AIR CONDITIONING SYSTEM

Info

Publication number: 20260029147
Type: Application
Filed: Sep 30, 2025
Publication Date: Jan 29, 2026
Applicant: QINGDAO HISENSE HITACHI AIR-CONDITIONING SYSTEMS CO., LTD. (Shandong)
Inventors: Zongchen SHAO (Qingdao), Xinyi LIU (Qingdao), Jiangnan WANG (Qingdao), Heng ZHANG (Qingdao), Jianjun MENG (Qingdao), Chen DONG (Qingdao)
Application Number: 19/344,580

Abstract

An air conditioning system is disclosed, having a defrosting mode, a cooling mode, and a heating mode. The defrosting mode includes a first defrosting mode and a second defrosting mode. The air conditioning system comprises: a compressor, an indoor heat exchanger, an outdoor unit, an outdoor heat exchanger assembly, a partition plate, a first fan, a second fan, and defrost pipeline. The compressor includes a suction port and a discharge port. A first end of the indoor heat exchanger is communicated with one of the suction port and the discharge port. The outdoor heat exchanger assembly includes a first part and a second part. The defrost pipeline is communicated with the discharge port.

Description

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of international application of PCT application serial no. PCT/CN2024/075343, filed on Feb. 1, 2024, which claims the priority benefit of China application No. 202310506265.8 filed on May 5, 2023 and Chinese Patent Application No. 202310502251.9, filed on May 5, 2023. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND Technical Field

The present disclosure relates to the field of air conditioning technologies, and in particular, to an air conditioning system.

Description of Related Art

When an air conditioning system operates in a heating mode, under certain conditions of temperature and humidity of external ambient, the outdoor heat exchanger assembly may frost, affecting the performance of the air conditioning system. Supplying the refrigerant discharged from the compressor to the outdoor heat exchanger assembly allows the use of the refrigerant's heat to defrost the outdoor heat exchanger assembly.

SUMMARY

An air conditioning system is provided, having a defrosting mode, a cooling mode, and a heating mode. The defrosting mode includes a first defrosting mode and a second defrosting mode. The air conditioning system includes: a compressor, an indoor heat exchanger, an outdoor unit, an outdoor heat exchanger assembly, a partition plate, a first fan, a second fan, and defrost pipeline. The outdoor unit includes a housing, wherein a cavity is defined within the housing. The compressor includes a suction port and a discharge port. A first end of the indoor heat exchanger is communicated with one of the suction port and the discharge port. The outdoor heat exchanger assembly includes a first part and a second part. The partition plate is disposed within the cavity and partitions the cavity into a first space and a second space independent of each other. The first fan and the first part are located in the first space, and the first fan is configured to increase an airflow velocity near the first part. The second fan and the second part are located in the second space, and the second fan is configured to increase an airflow velocity near the second part. The defrost pipeline is communicated with the discharge port. In a case where the air conditioning system operates in the first defrosting mode, the defrost pipeline is configured to transmit refrigerant discharged from the discharge port to one of the first part and the second part. In a case where the air conditioning system operates in the second defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the other of the first part and the second part. In a case where the air conditioning system operates in the first defrosting mode to defrost the first part, the first fan stops operating and the second fan operates normally, so that high-temperature and high-pressure gaseous refrigerant discharged from the discharge port is transmitted to the first part, and a refrigerant cycle is performed between the second part and the indoor heat exchanger to heat indoor air. In a case where the air conditioning system operates in the second defrosting mode to defrost the second part, the second fan stops operating and the first fan operates normally, so that the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port is transmitted to the second part for condensation and heat release, the condensed refrigerant is then transmitted to the first part for evaporation and heat absorption, and then returns to the compressor, and a refrigerant cycle is performed between the first part and the indoor heat exchanger to heat indoor air.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic diagram of an outdoor unit according to some embodiments;

FIG. 1B is a schematic diagram of another outdoor unit according to some embodiments;

FIG. 2 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 3 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 4 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 5 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 6 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 7 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 8 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 9 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 10 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 11 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 12 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 13 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 14 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 15 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 16 is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 17A is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 17B is a schematic diagram of yet another air conditioning system according to some embodiments;

FIG. 18 is a schematic diagram of a gas-liquid separator according to some embodiments;

FIG. 19 is a schematic diagram of an oil-gas separator according to some embodiments;

FIG. 20 is a flowchart of steps executed by a controller according to some embodiments;

FIG. 21 is another flowchart of steps executed by a controller according to some embodiments;

FIG. 22 is yet another flowchart of steps executed by a controller according to some embodiments;

FIG. 23 is yet another flowchart of steps executed by a controller according to some embodiments;

FIG. 24 is yet another flowchart of steps executed by a controller according to some embodiments;

FIG. 25 is yet another flowchart of steps executed by a controller according to some embodiments;

FIG. 26 is a flowchart of controlling the rotational speed of an indoor unit fan according to some embodiments;

FIG. 27 is a flowchart of controlling the opening degree of a sixth throttle valve according to some embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

The following will clearly and completely describe some embodiments of the present disclosure with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, not all of them. Based on the embodiments provided herein, all other embodiments obtained by persons of ordinary skill in the art shall fall within the protection scope of the present disclosure.

Unless the context requires otherwise, throughout the specification and claims, the term “comprise” and other forms such as the third person singular form “comprises” and the present participle form “comprising” are interpreted as open and inclusive, meaning “including, but not limited to”. In the description of the specification, terms such as “one embodiment”, “some embodiments”, “exemplary embodiments”, “example”, “specific example”, or “some examples” are intended to indicate that specific features, structures, materials, or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

Hereinafter, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with “first” and “second” may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise specified, “a plurality of” means two or more.

When describing some embodiments, the terms “coupled” and “connected” and their derivatives may be used. The term “connection” should be understood broadly. For example, “connection” may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection or an indirect connection through an intermediate medium. The term “coupled” indicates, for example, that two or more components have direct physical contact or electrical contact. The term “coupled” or “communicatively coupled” may also mean that two or more components are not in direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited by the content herein.

“A and/or B” includes the following three combinations: only A, only B, and a combination of A and B.

The use of “suitable for” or “configured to” herein means open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps.

In addition, the use of “based on” means open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values may, in practice, be based on additional conditions or values beyond those stated.

When an air conditioning system operates in a heating mode, under certain conditions of temperature and humidity of external ambient, the outdoor heat exchanger assembly may frost, leading to a decrease in system performance and heating capacity. After frosting, the air conditioning system initiates a defrosting procedure to defrost the outdoor heat exchanger assembly. Currently, there are mainly the following two implementations for defrosting.

In the first implementation, the air conditioning system uses a reverse cycle defrost method to defrost the outdoor heat exchanger assembly. By reversing the flow of refrigerant during heating, the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger assembly, utilizing the heat from the compressor to defrost the outdoor heat exchanger assembly. During reverse cycle defrosting, the air conditioning system stops heating the indoors and also requires the indoor heat exchanger to absorb some heat from the indoors, which lowers the indoor temperature, severely affects indoor thermal comfort, and reduces user experience. Additionally, the reverse cycle defrosting method requires changing the refrigerant flow direction. Particularly when switching back to heating mode operation after defrosting, since the gas-liquid separator stores a large amount of refrigerant during the defrosting process, after defrosting, when the compressor starts, the pressure difference between the high pressure at the discharge port and the low pressure at the suction port is established slowly, leading to a decrease in the heating capacity of the air conditioning system, affecting real-time heating capacity and indoor thermal comfort.

In the second implementation, the air conditioning system uses a bypass branch method to defrost the outdoor heat exchanger assembly. A bypass branch is provided on the compressor discharge pipe and is communicated with an inlet pipe of the outdoor heat exchanger. When defrosting operation is required, the refrigerant discharged from the compressor enters the outdoor heat exchanger through the bypass branch for defrosting. However, in this method, the heat source during defrosting is only the compression work of the compressor, resulting in poor defrosting reliability and a long defrosting time.

In both implementations described above, when the air conditioning system performs defrosting, it reduces the heating capacity provided to the indoors, affecting the comfort of indoor users in a heating environment.

Based on the above, some embodiments of the present disclosure provide an air conditioning system that can achieve uninterrupted heating during defrosting. The air conditioning system according to some embodiments of the present disclosure is described below.

Referring to FIGS. 2 and 3, in some embodiments, the air conditioning system 100 includes: a compressor 1, a first reversing valve 2, an indoor heat exchanger 3, an outdoor heat exchanger assembly 4, and defrost pipeline. The defrost pipeline includes a bypass branch 5 and a diverting branch 6. The compressor 1 includes a suction port 11 and a discharge port 12. For example, the suction port 11 of the compressor 1 is configured to suck in gaseous refrigerant so that the gaseous refrigerant enters the compression chamber of the compressor 1 through the suction port 11 and is compressed into high-temperature and high-pressure refrigerant. The high-temperature and high-pressure refrigerant gas is then discharged from the discharge port 12 of the compressor 1 and enters the air conditioning system 100 for circulation. For example, the air conditioning system 100 may include one or more compressors 1. For example, the compressor 1 may be a scroll compressor, a rotary compressor, a screw compressor, or other types of compressors.

Referring to FIG. 1A, the first part 41 may also be located below the second part 42.

Thus, the first defrost branch 61 and the second defrost branch 62 can be reasonably arranged in the air conditioning system 100, which is beneficial for reducing costs.

As shown in FIG. 1B, in some embodiments, the air conditioning system 100 further includes an outdoor unit. The outdoor unit includes a housing 40, a partition plate 48, a first part 41, a first fan 45, a second part 42, and a second fan 47.

In some embodiments, a cavity Q is defined within the housing 40. The partition plate 48 is disposed within the cavity Q and partitions the cavity Q into a first space Q1 and a second space Q2 independent of each other.

For example, the partition plate 48 may be arranged along the vertical direction. In this case, the first space Q1 and the second space Q2 may be arranged along the horizontal direction.

For example, the partition plate 48 may be arranged along the horizontal direction. In this case, the first space Q1 and the second space Q2 may be arranged along the vertical direction.

In some embodiments, as shown in FIG. 1B, the first part 41 and the first fan 45 are located in the first space Q1. The first fan 45 is configured to increase the airflow velocity near the first part 41. The second part 42 and the second fan 47 are located in the second space Q2. The second fan 47 is configured to increase the airflow velocity near the second part 42.

For example, the first fan 45 and the second fan 47 can be controlled independently.

It is understandable that when the first fan 45 is operating, it can increase the airflow velocity near the first part 41 and avoid affecting the airflow velocity near the second part 42. When the second fan 47 is operating, it can increase the airflow velocity near the second part 42 and avoid affecting the airflow velocity near the first part 41.

For example, referring to FIG. 1B, when the air conditioning system 100 operates in the first defrosting mode, the refrigerant discharged from the discharge port 12 is transmitted through the second defrost branch 62 to the first end of the first part 41 and discharged from the second end of the first part 41 to defrost the first part 41. The first fan 45 stops operating. The first end of the first part 41 is communicated with the second end of the indoor heat exchanger 3. The first end of the second part 42 is communicated with the suction port 11. The second end of the first part 41 is communicated with the second end of the second part 42. The first end of the indoor heat exchanger 3 is communicated with the discharge port 12. The second fan 47 operates normally. The second part 42 normally performs a refrigerant cycle with the indoor heat exchanger 3 to enable the indoor heat exchanger 3 to heat indoor air.

For example, referring to FIG. 1B, when the air conditioning system 100 operates in the first defrosting mode, the refrigerant discharged from the discharge port 12 is transmitted through the first defrost branch 61 to the second end of the first part 41 and discharged from the first end of the first part 41 to defrost the first part 41, and the first fan 45 stops operating. The first end of the first part 41 is communicated with the suction port 11. The first end of the second part 42 is communicated with the second end of the indoor heat exchanger 3. The second end of the first part 41 is communicated with the second end of the second part 42. The first end of the indoor heat exchanger 3 is communicated with the discharge port 12. The second fan 47 operates normally. The second part 42 normally performs a refrigerant cycle with the indoor heat exchanger 3 to enable the indoor heat exchanger 3 to heat indoor air.

For example, referring to FIG. 1B, when the air conditioning system 100 operates in the second defrosting mode, the refrigerant discharged from the discharge port 12 is transmitted through the first defrost branch 61 to the second end of the second part 42 and discharged from the first end of the second part 42 to defrost the second part 42, and the first fan 45 stops operating. The first end of the first part 41 is communicated with the second end of the indoor heat exchanger 3. The first end of the second part 42 is communicated with the suction port 11. The second end of the first part 41 is communicated with the second end of the second part 42. The first end of the indoor heat exchanger 3 is communicated with the discharge port 12. The second fan 47 operates normally. The second part 42 normally performs a refrigerant cycle with the indoor heat exchanger 3 to enable the indoor heat exchanger 3 to heat indoor air.

For example, referring to FIG. 1B, when the air conditioning system 100 operates in the second defrosting mode, the refrigerant discharged from the discharge port 12 is transmitted through the second defrost branch 62 to the first end of the second part 42 and discharged from the second end of the second part 42 to defrost the second part 42, and the first fan 45 stops operating. The first end of the first part 41 is communicated with the suction port 11. The first end of the second part 42 is communicated with the second end of the indoor heat exchanger 3. The second end of the first part 41 is communicated with the second end of the second part 42. The first end of the indoor heat exchanger 3 is communicated with the discharge port 12. The second fan 47 operates normally. The second part 42 normally performs a refrigerant cycle with the indoor heat exchanger 3 to enable the indoor heat exchanger 3 to heat indoor air.

In some embodiments, as shown in FIGS. 2, 3, and 4, when the air conditioning system 100 operates in the first defrosting mode, the first fan 45 stops operating. The first end of the first part 41 is communicated with the discharge port 12. The second end of the first part 41 is communicated with the suction port 11, so that the refrigerant in the compressor 1 enters the first part 41 from the discharge port 12 for defrosting and then returns to the compressor 1 via the suction port 11. The second fan 47 operates normally. The first end of the second part 42 is communicated with the first end of the indoor heat exchanger 3. The second end of the second part 42 is communicated with the suction port 11. The second end of the indoor heat exchanger 3 is communicated with the discharge port 12, to enable the indoor heat exchanger 3 to heat indoor air. As shown in FIGS. 2, 3, and 4, when the air conditioning system 100 operates in the second defrosting mode, the second fan 47 stops operating, the second end of the second part 42 is communicated with the discharge port 12. The first end of the second part 42 is communicated with the suction port 11, so that the refrigerant in the compressor 1 enters the second part 42 from the discharge port 12 for defrosting and then returns to the compressor 1 via the suction port 11. The first fan 45 operates normally. The first end of the first part 41 is communicated with the first end of the indoor heat exchanger 3. The second end of the first part 41 is communicated with the suction port 11. The second end of the indoor heat exchanger 3 is communicated with the discharge port 12, to enable the indoor heat exchanger 3 to heat indoor air.

In this way, when the air conditioning system 100 defrosts one of the first part 41 and the second part 42, it can use the other of the first part 41 and the second part 42 as an evaporator, so that the other of the first part 41 and the second part 42 continues to exchange heat with the nearby air, thereby maintaining the indoor heat exchanger 3 to continue heating the indoor air. This improves the defrosting efficiency for the first part 41 and the second part 42, and allows the air conditioning system 100 to provide uninterrupted heating to the indoors, thereby improving indoor comfort and the user experience of the air conditioning system 100.

It is understandable that when the air conditioning system 100 operates in the first defrosting mode, the refrigerant in the compressor 1 defrosts the first part 41. When the first fan 45 stops operating, it can prevent the surrounding cold air from lowering the temperature of the first part 41, allowing the first part 41 to maintain a high temperature state, thereby improving the defrosting efficiency of the first part 41. When the air conditioning system 100 operates in the second defrosting mode, the refrigerant in the compressor 1 defrosts the second part 42. When the second fan 47 stops operating, it can prevent the surrounding cold air from lowering the temperature of the second part 42, allowing the second part 42 to maintain a high temperature state, thereby improving the defrosting efficiency of the second part 42.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system 100 further includes a fourth throttle valve 51 and a fifth throttle valve 52. The fourth throttle valve 51 is connected in a pipeline between the second end of the first part 41 and the second end of the indoor heat exchanger 3. The fifth throttle valve 52 is connected in a pipeline between the second end of the second part 42 and the second end of the indoor heat exchanger 3.

The fourth throttle valve 51 is configured to control the on/off of the pipeline between the second end of the first part 41 and the second end of the indoor heat exchanger 3, and to throttle and reduce the pressure of the refrigerant flowing through the fourth throttle valve 51. That is, the opening degree of the fourth throttle valve 51 is adjustable. For example, the fourth throttle valve 51 can have a fully open state (the opening degree of the fourth throttle valve 51 is 100%), a fully closed state (the opening degree of the fourth throttle valve 51 is 0), and a throttling state (the opening degree of the fourth throttle valve 51 is between 0˜100%). When the fourth throttle valve 51 is in the fully closed state, the pipeline between the second end of the first part 41 and the second end of the indoor heat exchanger 3 is not communicated. When the fourth throttle valve 51 is in the fully open state and the throttling state, the pipeline between the second end of the first part 41 and the second end of the indoor heat exchanger 3 is open, and when the fourth throttle valve 51 is in the throttling state, the fourth throttle valve 51 can throttle and reduce the pressure of the refrigerant flowing through it.

The fifth throttle valve 52 is configured to control the on/off of the pipeline between the second end of the second part 42 and the second end of the indoor heat exchanger 3, and to throttle and reduce the pressure of the refrigerant flowing through the fifth throttle valve 52. That is, the opening degree of the fifth throttle valve 52 is adjustable. For example, the fifth throttle valve 52 can have a fully open state (the opening degree of the fifth throttle valve 52 is 100%), a fully closed state (the opening degree of the fifth throttle valve 52 is 0), and a throttling state (the opening degree of the fifth throttle valve 52 is between 0˜100%). When the fifth throttle valve 52 is in the fully closed state, the pipeline between the second end of the second part 42 and the second end of the indoor heat exchanger 3 is not communicated. When the fifth throttle valve 52 is in the fully open state and the throttling state, the pipeline between the second end of the second part 42 and the second end of the indoor heat exchanger 3 is open, and when the fifth throttle valve 52 is in the throttling state, the fifth throttle valve 52 can throttle and reduce the pressure of the refrigerant flowing through it.

It is understandable that, as shown in FIGS. 2, 3, and 4, when the fourth throttle valve 51 and the fifth throttle valve 52 are open, the refrigerant can flow to the first part 41 and the second part 42 respectively after flowing through the indoor heat exchanger 3; or, the refrigerant flowing through the first part 41 or the second part 42 can also flow to the indoor heat exchanger 3.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system further includes a first subcooling device 65. The first subcooling device 65 is communicated between the fourth throttle valve 51 and the second end of the indoor heat exchanger 3 and is configured to reduce the temperature of the refrigerant entering the fourth throttle valve 51 from the indoor heat exchanger 3. By providing the first subcooling device 65, the temperature of the refrigerant entering the fourth throttle valve 51 can be reduced, thereby avoiding excessive pressure changes in the refrigerant before entering the fourth throttle valve 51, reducing the flash gas generated during the throttling process of the air conditioning system 100, which is beneficial to improving the cooling capacity of the air conditioning system 100, and also improving the operation stability of the compressor 1, thereby improving the stability and reliability of the air conditioning system 100.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system further includes a second subcooling device 66. The second subcooling device 66 is communicated between the fifth throttle valve 52 and the second end of the indoor heat exchanger 3 and is configured to reduce the temperature of the refrigerant entering the fifth throttle valve 52 from the indoor heat exchanger 3.

By providing the second subcooling device 66, the temperature of the refrigerant entering the fifth throttle valve 52 can be reduced, thereby avoiding excessive pressure changes in the refrigerant before entering the fifth throttle valve 52, reducing the flash gas generated during the throttling process of the air conditioning system 100, which is beneficial to improving the cooling capacity of the air conditioning system 100, and also improving the operation stability of the compressor 1, thereby improving the stability and reliability of the air conditioning system 100.

It should be noted that flash gas refers to the gas produced by instantaneous vaporization of some liquid refrigerant due to a sudden pressure drop in a liquid refrigeration system.

As shown in FIG. 2, in some embodiments, the air conditioning system 100 further includes a first branch 91. A first end of the first branch 91 is communicated with the third valve port 23, and a second end of the first branch 91 is communicated with the first end of the second part 42.

In some embodiments, the air conditioning system 100 further includes a second branch 92. A first end of the second branch 92 is communicated with the discharge port 12, and a second end of the second branch 92 is communicated with the first end of the second part 42.

In some embodiments, the air conditioning system 100 further includes a third branch 93. A first end of the third branch 93 is communicated with the discharge port 12, and a second end of the third branch 93 is communicated with the pipeline between the fourth throttle valve 51 and the second end of the first part 41.

In some embodiments, the air conditioning system 100 further includes a fourth branch 94. A first end of the fourth branch 94 is communicated with the pipeline between the fourth throttle valve 51 and the second end of the first part 41, and a second end of the fourth branch 94 is communicated with the pipeline between the fifth throttle valve 52 and the second end of the second part 42.

In some embodiments, the air conditioning system 100 further includes a first on-off valve 63. The first on-off valve 63 is connected in series with the first branch 91. The first on-off valve 63 is configured to control the on/off of the first branch 91, that is, to control the on/off between the third valve port 23 and the first end of the second part 42.

In some embodiments, the air conditioning system 100 further includes a sixth throttle valve 53. The sixth throttle valve 53 is connected in series with the second branch 92. The sixth throttle valve 53 is configured to control the on/off of the second branch 92 and to throttle and reduce the pressure of the refrigerant flowing through the sixth throttle valve 53. That is, the opening degree of the sixth throttle valve 53 is adjustable. For example, the sixth throttle valve 53 can have a fully open state (the opening degree of the sixth throttle valve 53 is 100%), a fully closed state (the opening degree of the sixth throttle valve 53 is 0), and a throttling state (the opening degree of the sixth throttle valve 53 is between 0˜100%). When the sixth throttle valve 53 is in the fully closed state, the second branch 92 is not communicated. When the sixth throttle valve 53 is in the fully open state and the throttling state, the second branch 92 is open, and when the sixth throttle valve 53 is in the throttling state, the sixth throttle valve 53 can throttle and reduce the pressure of the refrigerant flowing through it.

In some embodiments, the air conditioning system 100 further includes a second on-off valve 64. The second on-off valve 64 is connected in series with the third branch 93. The second on-off valve 64 is configured to control the on/off of the third branch 93.

In some embodiments, the air conditioning system 100 further includes a seventh throttle valve 54. The seventh throttle valve 54 is connected in series with the fourth branch 94. The seventh throttle valve 54 is configured to control the on/off of the fourth branch 94 and to throttle and reduce the pressure of the refrigerant flowing through the seventh throttle valve 54. That is, the opening degree of the seventh throttle valve 54 is adjustable. For example, the seventh throttle valve 54 can have a fully open state (the opening degree of the seventh throttle valve 54 is 100%), a fully closed state (the opening degree of the seventh throttle valve 54 is 0), and a throttling state (the opening degree of the seventh throttle valve 54 is between 0˜100%). When the seventh throttle valve 54 is in the fully closed state, the fourth branch 94 is not communicated. When the seventh throttle valve 54 is in the fully open state and the throttling state, the fourth branch 94 is open, and when the seventh throttle valve 54 is in the throttling state, the seventh throttle valve 54 can throttle and reduce the pressure of the refrigerant flowing through it.

As shown in FIG. 3, the difference from the air conditioning system 100 in the above some embodiments is that the air conditioning system 100 shown in FIG. 3 further includes a second reversing valve 10. The second reversing valve 10 includes a first port 101, a second port 102, and a third port 103. The first port 101 is communicated with the discharge port 12; the second port 102 is communicated with the suction port 11; the third port 103 is communicated with the first end of the second part 42.

In some embodiments, the second reversing valve 10 may be a three-way reversing valve or a four-way reversing valve. For example, when the second reversing valve 10 is a four-way reversing valve, the second reversing valve 10 further includes a fourth port 104. The fourth port 104 is closed, and the third port 103 is communicatively switched between the first port 101 and the second port 102.

In some embodiments, when the second reversing valve 10 is energized, the first port 101 is communicated with the third port 103; when the second reversing valve 10 is de-energized, the second port 102 is communicated with the third port 103.

In some embodiments, when the second reversing valve 10 is energized, the second port 102 is communicated with the third port 103; when the second reversing valve 10 is de-energized, the first port 101 is communicated with the third port 103.

In some embodiments, when the second reversing valve 10 is a three-way reversing valve, the type of the three-way reversing valve may be a pilot-operated three-way valve or other low-resistance three-way valve.

As shown in FIG. 4, in some embodiments, the air conditioning system 100 further includes a fifth branch 95 and a sixth branch 96. A first end of the fifth branch 95 is communicated with the discharge port 12, and a second end of the fifth branch 95 is communicated with the pipeline between the fifth throttle valve 52 and the second end of the second part 42. A first end of the sixth branch 96 is communicated with the pipeline between the fourth throttle valve 51 and the second end of the first part 41, and a second end of the sixth branch 96 is communicated with the pipeline between the first branch 91 and the first end of the second part 42.

The air conditioning system 100 further includes an eighth throttle valve 55. The eighth throttle valve 55 is connected in series with the fifth branch 95. The eighth throttle valve 55 is configured to control the on/off of the fifth branch 95 and to throttle and reduce the pressure of the refrigerant flowing through the eighth throttle valve 55. That is, the opening degree of the eighth throttle valve 55 is adjustable. For example, the eighth throttle valve 55 can have a fully open state (the opening degree of the eighth throttle valve 55 is 100%), a fully closed state (the opening degree of the eighth throttle valve 55 is 0), and a throttling state (the opening degree of the eighth throttle valve 55 is between 0˜100%). When the eighth throttle valve 55 is in the fully closed state, the fifth branch 95 is not communicated. When the eighth throttle valve 55 is in the fully open state and the throttling state, the fifth branch 95 is open, and when the eighth throttle valve 55 is in the throttling state, the eighth throttle valve 55 can throttle and reduce the pressure of the refrigerant flowing therethrough.

The air conditioning system 100 further includes a ninth throttle valve 56. The ninth throttle valve 56 is connected in series with the sixth branch 96. The ninth throttle valve 56 is configured to control the on/off of the sixth branch 96 and to throttle and reduce the pressure of the refrigerant flowing through the ninth throttle valve 56. That is, the opening degree of the ninth throttle valve 56 is adjustable. For example, the ninth throttle valve 56 can have a fully open state (the opening degree of the ninth throttle valve 56 is 100%), a fully closed state (the opening degree of the ninth throttle valve 56 is 0), and a throttling state (the opening degree of the ninth throttle valve 56 is between 0˜100%). When the ninth throttle valve 56 is in the fully closed state, the sixth branch 96 is not communicated. When the ninth throttle valve 56 is in the fully open state and the throttling state, the sixth branch 96 is open, and when the ninth throttle valve 56 is in the throttling state, the ninth throttle valve 56 can throttle and reduce the pressure of the refrigerant flowing through it.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system 100 further includes an indoor unit fan 30.

The indoor unit fan 30 is configured to increase the heat exchange speed of the indoor heat exchanger 3.

In some embodiments, the air conditioning system 100 has a cooling mode, a heating mode, a first defrosting mode, and a second defrosting mode. Below, the control process of the air conditioning system 100 for each component and the refrigerant flow direction during the operation of the cooling mode, the heating mode, the first defrosting mode, and the second defrosting mode are described in detail.

<Cooling Mode>

Referring to FIG. 5, when the air conditioning system 100 operates in the cooling mode, the first valve port 21 of the first reversing valve 2 is communicated with the third valve port 23, the second valve port 22 is communicated with the fourth valve port 24, the first on-off valve 63 is on, the second on-off valve 64 is off, the fourth throttle valve 51 and the fifth throttle valve 52 are throttled, the sixth throttle valve 53 is fully open or fully closed, the seventh throttle valve 54 is fully closed, and the first fan 45 and the second fan 47 are operating.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the first reversing valve 2 through the first valve port 21 and flows out of the first reversing valve 2 from the third valve port 23. The refrigerant flowing out of the third valve port 23 flows to the first part 41 and the second part 42, and after fully exchanging heat in the first part 41 and the second part 42, it becomes high-pressure and medium-temperature liquid refrigerant. Then, the high-pressure and medium-temperature liquid refrigerant flows out of the first part 41 and the second part 42, flows through the fourth throttle valve 51 and the fifth throttle valve 52, and is throttled by the fourth throttle valve 51 and the fifth throttle valve 52 into low-temperature and low-pressure two-phase refrigerant. Then, the low-temperature and low-pressure two-phase refrigerant flows into the indoor heat exchanger 3 and evaporates in the indoor heat exchanger 3, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the low-temperature and low-pressure gaseous refrigerant flows through the second valve port 22 and the fourth valve port 24 sequentially and flows back to the suction port 11 of the compressor 1, thus completing the cooling cycle of the air conditioning system 100.

<Heating Mode>

Referring to FIG. 6, when the air conditioning system 100 operates in the heating mode, the first valve port 21 of the first reversing valve 2 is communicated with the second valve port 22, the third valve port 23 is communicated with the fourth valve port 24, the first on-off valve 63 is on, the second on-off valve 64 is off, the fourth throttle valve 51 and the fifth throttle valve 52 are throttled, the sixth throttle valve 53 and the seventh throttle valve 54 are fully closed, and the first fan 45 and the second fan 47 are operating.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the first reversing valve 2 through the first valve port 21 and flows out of the first reversing valve 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3. After exchanging heat in the indoor heat exchanger 3, it is cooled into high-pressure and medium-temperature liquid refrigerant, and then flows from the indoor heat exchanger 3 to the fourth throttle valve 51 and the fifth throttle valve 52. At throttled and pressure-reduced by the fourth throttle valve 51 and the fifth throttle valve 52, the refrigerant flows into the first part 41 and the second part 42 respectively and evaporates in the first part 41 and the second part 42, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the refrigerant flowing out of the first part 41 and the second part 42 flows through the third valve port 23 and the fourth valve port 24 sequentially, and flows back to the suction port 11 of the compressor 1, thus completing the heating cycle of the air conditioning system 100.

<First Defrosting Mode>

Referring to FIG. 7, when the air conditioning system 100 operates in the first defrosting mode, it defrosts the first part 41, controls the first valve port 21 of the first reversing valve 2 to be communicated with the second valve port 22, controls the third valve port 23 to be communicated with the fourth valve port 24, controls the first on-off valve 63 and the second on-off valve 64 to be on, controls the fifth throttle valve 52 to be throttled, controls the fourth throttle valve 51, the sixth throttle valve 53 and the seventh throttle valve 54 to be fully closed, the first fan 45 stops operating, and the second fan 47 is operating.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the first reversing valve 2 and the first branch 91 respectively. The refrigerant flowing to the first reversing valve 2 flows into the first reversing valve 2 through the first valve port 21 and flows out of the first reversing valve 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 fully exchanges heat in the indoor heat exchanger 3 and is cooled into high-pressure high-temperature two-phase refrigerant, and then flows from the indoor heat exchanger 3 to the fifth throttle valve 52. The fifth throttle valve 52 throttles the refrigerant flowing therethrough into low-temperature and low-pressure two-phase refrigerant. Then, the low-temperature and low-pressure two-phase refrigerant flows to the second part 42 and evaporates in the second part 42, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the low-temperature and low-pressure gaseous refrigerant flows through the first on-off valve 63, the third valve port 23, the fourth valve port 24, and the gas-liquid separator 7 sequentially, and enters the compressor 1 for compression.

The high-temperature and high-pressure gaseous refrigerant flowing to the first branch 91 enters the first part 41 through the second on-off valve 64 to defrost the first part 41. The refrigerant entering the first part 41 is cooled into low-pressure low-temperature gaseous refrigerant. Then, the low-pressure low-temperature gaseous refrigerant flows through the third valve port 23, the fourth valve port 24, and the gas-liquid separator 7 sequentially, and enters the compressor 1 for compression.

Thus, during the process of defrosting the first part 41, by stopping the operation of the first fan 45, it can prevent excessive heat dissipation from the first part 41 to the outdoor environment, and increase the discharge pressure of the compressor 1, improving defrosting efficiency. By operating the second fan 47, it can accelerate the speed at which the second part 42 absorbs heat from the outside, improving the heating capacity of the indoor unit and the defrosting speed of the first part 41. The purpose of adjusting the fifth throttle valve 52 to the throttling state is to use the second part 42 as an evaporator and regulate the flow rate of the refrigerant flowing from the indoor heat exchanger 3 into the second part 42.

In the above process of defrosting the first part 41, the pressure and temperature of the refrigerant in the indoor heat exchanger 3 are high, and the sensible heat of the refrigerant flowing out of the compressor 1 is directly used for defrosting. The above process of defrosting the first part 41 can be called high-pressure sensible heat defrosting.

<Second Defrosting Mode>

Referring to FIG. 8, when the air conditioning system 100 operates in the second defrosting mode, it defrosts the second part 42, controls the first valve port 21 of the first reversing valve 2 to be communicated with the second valve port 22, controls the third valve port 23 to be communicated with the fourth valve port 24, controls the first on-off valve 63 and the second on-off valve 64 to be off, controls the fifth throttle valve 52 to be fully closed, controls the fourth throttle valve 51, the sixth throttle valve 53 and the seventh throttle valve 54 to be throttled, the first fan 45 is operating, and the second fan 47 stops operating.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the first reversing valve 2 and the second branch 92 respectively.

The refrigerant flowing to the first reversing valve 2 flows into the first reversing valve 2 through the first valve port 21 and flows out of the first reversing valve 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 fully exchanges heat in the indoor heat exchanger 3 and is cooled into high-pressure high-temperature two-phase refrigerant, and then flows from the indoor heat exchanger 3 to the fourth throttle valve 51. The fourth throttle valve 51 throttles the flowing refrigerant into low-temperature and low-pressure two-phase refrigerant. Then, the low-temperature and low-pressure two-phase refrigerant flows to the first part 41 and evaporates in the first part 41, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the low-temperature and low-pressure gaseous refrigerant flows through the third valve port 23, the fourth valve port 24, and the gas-liquid separator 7 sequentially, and enters the compressor 1 for compression.

The high-temperature and high-pressure gaseous refrigerant flowing to the second branch 92 flows into the second part 42, using the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 to remove the frost on the second part 42. The refrigerant is cooled into medium-pressure medium-temperature liquid refrigerant in the second part 42. Then, the medium-temperature medium-pressure liquid refrigerant is throttled by the seventh throttle valve 54 into low-temperature and low-pressure two-phase refrigerant. Then, the low-temperature and low-pressure two-phase refrigerant enters the first part 41 and evaporates, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the low-temperature and low-pressure gaseous refrigerant flows through the third valve port 23, the fourth valve port 24, and the gas-liquid separator 7 sequentially, and enters the compressor 1 for compression, thus completing the defrosting refrigerant cycle for the second part 42.

During the process of defrosting the second part 42, by stopping the operation of the second fan 47, it can prevent excessive heat dissipation to the outdoor environment, and increase the discharge pressure of the compressor 1, improving defrosting efficiency. By operating the first fan 45, it can accelerate the speed at which the first part 41 absorbs heat from the outside, improving the heating capacity of the indoor unit and the defrosting speed of the second part 42. The purpose of adjusting the sixth throttle valve 53 to the throttling state is to convert the second part 42 from an evaporator to a condenser. Off of the first on-off valve 63 can block the refrigerant in the second part 42 from flowing into the gas-liquid separator 7. Throttling the fourth throttle valve 51 can regulate the flow rate of the refrigerant flowing from the indoor heat exchanger into the first part 41. The fifth throttle valve 52 is fully closed while the seventh throttle valve 54 is throttled, which can regulate the flow rate of the refrigerant flowing from the second part 42 into the first part 41.

Thus, the air conditioning system 100 can alternately defrost the first part 41 and the second part 42, and can provide uninterrupted heating to the indoors during the defrosting process, improving the user experience of the air conditioning system 100. Moreover, in the second defrosting mode, the pressure of the refrigerant in the second part 42 can be controlled through the sixth throttle valve 53, which can control the flow rate of the refrigerant during the defrosting of the second part 42, avoiding energy waste, and also allowing the discharge pressure of the compressor 1 to increase. In this way, without affecting the defrosting efficiency, more heat can be used to increase the indoor temperature, so that good indoor heating effect is also achieved while defrosting the second part 42.

In the above process of defrosting the second part 42, the refrigerant pressure and temperature in the indoor heat exchanger 3 are low, and the phase change heat release of the refrigerant flowing from the compressor 1 to the second part 42 can be used to defrost the second part 42. This process of defrosting the second part 42 can be called pressure-controlled latent heat defrosting.

In some embodiments, the air conditioning system 100 has a cooling mode, a heating mode, a first defrosting mode, and a second defrosting mode. Below, the control process of the air conditioning system 100 for each component and the refrigerant flow direction during the operation of the cooling mode, the heating mode, the first defrosting mode, and the second defrosting mode are described in detail.

<Cooling Mode>

Referring to FIG. 9, the air conditioning system 100 further includes a second reversing valve 10, and does not include the sixth throttle valve 53 and the first on-off valve 63. The difference from the air conditioning system 100 shown in FIG. 5 is that, when the air conditioning system 100 operates in the cooling mode, the first port 101 of the second reversing valve 10 is communicated with the third port 103.

In this case, the flow direction of part of the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 through the first part 41 is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 5, and will not be repeated here.

Another part of the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the second reversing valve 10 through the first port 101 and flows out of the second reversing valve 10 from the third port 103. The refrigerant flowing out of the third port 103 flows to the second part 42, and after fully exchanging heat in the second part 42, it becomes high-pressure and medium-temperature liquid refrigerant. Then, the high-pressure and medium-temperature liquid refrigerant flows out of the second part 42, flows through the fifth throttle valve 52, and is throttled by the fifth throttle valve 52 into low-temperature and low-pressure two-phase refrigerant. Then, the low-temperature and low-pressure two-phase refrigerant flows into the indoor heat exchanger 3 and evaporates in the indoor heat exchanger 3, becoming low-temperature and low-pressure gaseous refrigerant. Finally, the low-temperature and low-pressure gaseous refrigerant flows through the second valve port 22 and the fourth valve port 24 sequentially, and flows back to the suction port 11 of the compressor 1. Thus, the cooling cycle of the air conditioning system 100 is completed.

<Heating Mode>

Referring to FIG. 10, the air conditioning system 100 further includes a second reversing valve 10, and does not include the sixth throttle valve 53 and the first on-off valve 63. The difference from the air conditioning system 100 shown in FIG. 5 is that, when the air conditioning system 100 operates in the heating mode, the second port 102 of the second reversing valve 10 is communicated with the third port 103.

In this case, the similarities of the refrigerant flow direction through the first part 41 with the air conditioning system 100 in the embodiment shown in FIG. 6 will not be repeated. The difference is that the refrigerant flowing out of the second part 42 flows through the third port 103 and the second port 102 sequentially, and flows back to the suction port 11 of the compressor 1.

<First Defrosting Mode>

Referring to FIG. 11, the difference from the air conditioning system 100 shown in FIG. 7 is that, the air conditioning system 100 further includes a second reversing valve 10, and does not include the sixth throttle valve 53 and the first on-off valve 63. When the air conditioning system 100 operates in the first defrosting mode, it controls the second port 102 of the second reversing valve 10 to be communicated with the third port 103.

In this case, the similarities of the refrigerant flow direction of the air conditioning system 100 with the embodiment shown in FIG. 7 will not be repeated. The difference is that, the gaseous refrigerant evaporated in the second part 42, becoming low-temperature and low-pressure, flows through the third port 103, the second port 102, and the gas-liquid separator 7 sequentially, and enters the compressor 1 for compression.

<Second Defrosting Mode>

Referring to FIG. 12, the difference from the air conditioning system 100 shown in FIG. 8 is that, the air conditioning system 100 further includes a second reversing valve 10, and does not include the sixth throttle valve 53 and the first on-off valve 63. When the air conditioning system 100 operates in the second defrosting mode, the first port 101 of the second reversing valve 10 is communicated with the third port 103 of the second reversing valve 10.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the first reversing valve 2 and the second reversing valve 10 respectively.

The refrigerant flow direction to the first reversing valve 2 is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 8 and will not be repeated here.

The refrigerant flow direction to the second reversing valve 10 is similar to the refrigerant flow direction to the second branch in the embodiment of the air conditioning system 100 shown in FIG. 8. The similarities will not be repeated. The difference is that the refrigerant flows through the first port 101 and the third port 103, and flows into the second part 42.

Thus, the air conditioning system 100 can alternately defrost the first part 41 and the second part 42, and can provide uninterrupted heating to the indoors during the defrosting process, improving the user experience of the air conditioning system 100.

In some embodiments, the air conditioning system 100 has a cooling mode, a heating mode, a first defrosting mode, and a second defrosting mode. Below, the control process of the air conditioning system 100 for each component and the refrigerant flow direction during the operation of the cooling mode, the heating mode, the first defrosting mode, and the second defrosting mode are described in detail.

<Cooling Mode>

Referring to FIG. 13, the difference from the air conditioning system 100 shown in FIG. 5 is that, the air conditioning system 100 further includes a fifth branch 95, a sixth branch 96, an eighth throttle valve 55, and a ninth throttle valve 56, and does not include the fourth branch 94, the sixth throttle valve 53, and the seventh throttle valve 54. When the air conditioning system 100 operates in the cooling mode, the eighth throttle valve 55 and the ninth throttle valve 56 are fully closed.

In this case, the refrigerant flow direction is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 5 and will not be repeated here.

<Heating Mode>

Referring to FIG. 14, the difference from the air conditioning system 100 shown in FIG. 6 is that, the air conditioning system 100 further includes a fifth branch 95, a sixth branch 96, an eighth throttle valve 55, and a ninth throttle valve 56, and does not include the fourth branch 94, the sixth throttle valve 53, and the seventh throttle valve 54. When the air conditioning system 100 operates in the heating mode, the eighth throttle valve 55 and the ninth throttle valve 56 are fully closed, and the first fan 45 and the second fan 47 are operating.

In this case, the refrigerant flow direction is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 6 and will not be repeated here.

<First Defrosting Mode>

Referring to FIG. 17, the difference from the air conditioning system 100 shown in FIG. 7 is that, the air conditioning system 100 further includes a fifth branch 95, a sixth branch 96, an eighth throttle valve 55, and a ninth throttle valve 56, and does not include the fourth branch 94, the sixth throttle valve 53, and the seventh throttle valve 54. When the air conditioning system 100 operates in the first defrosting mode, it controls the eighth throttle valve 55 and the ninth throttle valve 56 to be fully closed.

In this case, the refrigerant flow direction is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 7 and will not be repeated here.

<Second Defrosting Mode>

Referring to FIG. 16, the difference from the air conditioning system 100 shown in FIG. 8 is that, the air conditioning system 100 further includes a fifth branch 95, a sixth branch 96, an eighth throttle valve 55, and a ninth throttle valve 56, and does not include the fourth branch 94, the sixth throttle valve 53, and the seventh throttle valve 54. When the air conditioning system 100 operates in the second defrosting mode, it controls the eighth throttle valve 55 and the ninth throttle valve 56 to be throttled.

In this case, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the first reversing valve 2 and the fifth branch 95 respectively.

The refrigerant flow direction to the first reversing valve 2 is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 8 and will not be repeated here.

The refrigerant flow direction to the fifth branch 95 is similar to that of the air conditioning system 100 in the embodiment shown in FIG. 8. The similarities will not be repeated. The difference is that the medium-pressure medium-temperature liquid refrigerant cooled in the second part 42 is throttled by the fifth branch 95 and the ninth throttle valve 56 into low-temperature and low-pressure two-phase refrigerant.

Thus, the air conditioning system 100 can alternately defrost the first part 41 and the second part 42, and can provide uninterrupted heating to the indoors during the defrosting process, improving the user experience of the air conditioning system 100.

In some embodiments, when the air conditioning system 100 operates in the first defrosting mode or the second defrosting mode, the indoor unit fan 30 can be controlled to stop operating. This can avoid excessive heat dissipation to the indoor environment during the defrosting process, thereby increasing the discharge pressure of the compressor 1 and improving defrosting efficiency. Alternatively, the indoor unit fan 30 can be controlled to operate at a low rotational speed state, which can maintain the temperature of the indoor heat exchanger 3 and help to improve the indoor heating effect during the defrosting process.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system 100 further includes a first temperature sensor 411 and a third temperature sensor 412. The first temperature sensor 411 is arranged on the pipeline at the first end of the first part 41 and is configured to detect the pipeline temperature Tg1 at the first end of the first part 41. The third temperature sensor 412 is arranged on the pipeline at the second end of the second part 42 and is configured to detect the pipeline temperature Tg2 at the second end of the second part 42.

In some embodiments, the fourth throttle valve 51, the fifth throttle valve 52, the sixth throttle valve 53, the seventh throttle valve 54, the eighth throttle valve 55, and the ninth throttle valve 56 are electronic expansion valves. This can improve the operating speed and control accuracy of the air conditioning system 100.

In some embodiments, referring to FIGS. 17A and 17B, the outdoor heat exchanger assembly 4 includes a first part 41 and a second part 42. The second end of the first part 41 is communicated with the second end of the second part 42. The first end of one of the first part 41 and the second part 42 is communicated with the third valve port 23. The first end of the other of the first part 41 and the second part 42 is communicated with the second end of the indoor heat exchanger 3. It is understandable that the first part 41 and the second part 42 are connected in series, and the refrigerant can flow through the first part 41 and the second part 42 sequentially. The first end of the bypass branch 5 is communicated with the discharge port 12. The diverting branch 6 includes a first defrost branch 61 and a second defrost branch 62. The first end of the first defrost branch 61 is communicated with the second end of the bypass branch 5. The second end of the first defrost branch 61 is communicated with the pipeline between the first part 41 and the second part 42. The first end of the second defrost branch 62 is communicated with the second end of the bypass branch 5. The second end of the second defrost branch 62 is communicated with the first end of the other of the first part 41 and the second part 42, thereby communicating with the second end of the indoor heat exchanger 3. For example, the diverting branch 6 further includes a first throttle valve 611. The first throttle valve 611 is arranged on the first defrost branch 61. The first throttle valve 611 is connected in series with the first defrost branch 61. For example, the diverting branch 6 further includes a second throttle valve 621. The second throttle valve 621 is arranged on the second defrost branch 62. The second throttle valve 621 is connected in series with the second defrost branch 62. The first throttle valve 611 is configured to control the on/off of the first defrost branch 61 and to throttle and reduce the pressure of the refrigerant flowing through the first throttle valve 611. That is, the opening degree of the first throttle valve 611 is adjustable. For example, the first throttle valve 611 can have a fully open state (the opening degree of the first throttle valve 611 is 100%), a fully closed state (the opening degree of the first throttle valve 611 is 0), and a throttling state (the opening degree of the first throttle valve 611 is between 0˜100%). When the first throttle valve 611 is in the fully closed state, the first defrost branch 61 is not communicated. When the first throttle valve 611 is in the fully open state and the throttling state, the first defrost branch 61 is open, and when the first throttle valve 611 is in the throttling state, the first throttle valve 611 can throttle and reduce the pressure of the refrigerant flowing through it. The second throttle valve 621 is configured to control the on/off of the second defrost branch 62 and to throttle and reduce the pressure of the refrigerant flowing through the second throttle valve 621. That is, the opening degree of the second throttle valve 621 is adjustable. For example, the second throttle valve 621 can have a fully open state (the opening degree of the second throttle valve 621 is 100%), a fully closed state (the opening degree of the second throttle valve 621 is 0), and a throttling state (the opening degree of the second throttle valve 621 is between 0˜100%). When the second throttle valve 621 is in the fully closed state, the second defrost branch 62 is not communicated. When the second throttle valve 621 is in the fully open state and the throttling state, the second defrost branch 62 is open, and when the second throttle valve 621 is in the throttling state, the second throttle valve 621 can throttle and reduce the pressure of the refrigerant flowing through it. The high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 can flow through the bypass branch 5, the first defrost branch 61, and the first throttle valve 611, and flow to the pipeline between the first part 41 and the second part 42, or can flow through the bypass branch 5, the second defrost branch 62, and the second throttle valve 621, and flow to the first end of the other of the first part 41 and the second part 42. In some embodiments, the first part 41 and the second part 42 in the outdoor heat exchanger assembly 4 can be arranged in various ways.

For example, as shown in FIGS. 17A and 17B, the first end of the second part 42 is communicated with the third valve port 23, and the first end of the first part 41 is communicated with the second end of the indoor heat exchanger 3. In this way, when the first part 41 is frosted, by controlling the second throttle valve 621 to be open and the first throttle valve 611 to be close, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 enters the first part 41 along the bypass branch 5, the second defrost branch 62, and the second throttle valve 621, thereby defrosting the first part 41. Moreover, when defrosting of the first part 41 is not required, by controlling the second throttle valve 621 to be close, it can prevent the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 from flowing to the first defrost branch 61 and the second defrost branch 62, thereby avoiding affecting the normal operation of the air conditioning system 100 and improving the reliability of the air conditioning system 100 operation. When the second part 42 is frosted, by controlling the first throttle valve 611 to be open and the second throttle valve 621 to be close, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 enters the second part 42 along the bypass branch 5, the first defrost branch 61, and the first throttle valve 611, thereby defrosting the second part 42. Moreover, when defrosting of the second part 42 is not required, by controlling the first throttle valve 611 to be close, it can block the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 from flowing to the first defrost branch 61, thereby avoiding affecting the normal operation of the air conditioning system 100 and improving the reliability of the air conditioning system 100 operation. For example, as shown in FIGS. 17A and 17B, the first end of the first part 41 is communicated with the third valve port 23, and the first end of the second part 42 is communicated with the second end of the indoor heat exchanger 3. In this way, when the first part 41 is frosted, by controlling the second throttle valve 621 to be close and the first throttle valve 611 to be open, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 enters the first part 41 along the bypass branch 5, the first defrost branch 61, and the first throttle valve 611, thereby defrosting the first part 41. Moreover, when defrosting of the first part 41 is not required, by controlling the first throttle valve 611 to be close, it can block the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 from flowing to the first defrost branch 61, thereby avoiding affecting the normal operation of the air conditioning system 100 and improving the reliability of the air conditioning system 100 operation. When the second part 42 is frosted, by controlling the first throttle valve 611 to be close and the second throttle valve 621 to be open, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 enters the second part 42 along the bypass branch 5, the second defrost branch 62, the second throttle valve 621, and the first end of the second part 42, thereby defrosting the second part 42. Moreover, when defrosting of the second part 42 is not required, by controlling the second throttle valve 621 to be close, it can block the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 from flowing to the second defrost branch 62, thereby avoiding affecting the normal operation of the air conditioning system 100 and improving the reliability of the air conditioning system 100 operation. In some embodiments, the air conditioning system 100 has a cooling mode, a heating mode, a first defrosting mode, and a second defrosting mode. When the outdoor heat exchanger assembly frosts, during the operating process of the air conditioning system 100 operating in the defrosting mode, the heat of the refrigerant discharged from the compressor 1 can be used to defrost the outdoor heat exchanger assembly.

In some embodiments, the defrost pipeline further includes a check valve 612. The check valve 612 is connected in series with the pipeline between the first throttle valve 611 and the second end of the first defrost branch 61. The flow direction of the check valve 612 is direction from the first throttle valve 611 towards the second end of the first defrost branch 61. The check valve 612 is configured to control the refrigerant to flow from the first throttle valve 611 to the second end of the first defrost branch 61 and to block the refrigerant from flowing from the second end of the first defrost branch 61 to the first throttle valve 611.

With the above arrangement, it can block the refrigerant from flowing from the second end of the first defrost branch 61 to the first throttle valve 611 during cooling or heating of the air conditioning system 100, thereby affecting the cooling/heating capacity and efficiency.

In some embodiments, referring to FIGS. 17A and 17B, the third throttle valve 43, the first throttle valve 611, and the second throttle valve 621 are electronic expansion valves. This can improve the operating speed and accuracy of the air conditioning system 100.

In some embodiments, the third throttle valve 43, the first throttle valve 611, and the second throttle valve 621 are thermal expansion valves.

In some embodiments, the first throttle valve 611 and the second throttle valve 621 are solenoid valves or solenoid valves connected in series with pressure reducers.

In some embodiments, the first part 41 and the second part 42 may be independent heat exchangers respectively. Thus, when one of the first part 41 and the second part 42 is damaged during the operation of the air conditioning system 100 in cooling mode or heating mode, the air conditioning system 100 can avoid stopping work, thereby improving the operational stability and reliability of the air conditioning system 100.

Referring to FIGS. 17A and 17B, the air conditioning system 100 further includes a subcooler 44. The subcooler 44 is connected in the pipeline between the third throttle valve 43 and the second end of the indoor heat exchanger 3. By providing the subcooler 44, during the process of the refrigerant flowing from the indoor heat exchanger 3 to the third throttle valve 43, the subcooler 44 can cool the refrigerant, thereby reducing the temperature of the refrigerant entering the third throttle valve 43, which can avoid excessive pressure changes in the refrigerant before entering the fourth throttle valve 51 and the fifth throttle valve 52 (refer to FIG. 16), reduce the flash gas generated during the throttling process of the air conditioning system 100, which is beneficial to improving the cooling capacity of the air conditioning system 100, and also improve the stability of the compressor 1 operation, thereby improving the stability and reliability of the air conditioning system 100.

Referring to FIGS. 17A and 17B, the air conditioning system 100 further includes a first shut-off valve 31 and a second shut-off valve 32. The first shut-off valve 31 is communicated with the first end of the indoor heat exchanger 3 and is configured to control the on/off of the pipeline at the first end of the indoor heat exchanger 3. The second shut-off valve 32 is communicated with the second end of the indoor heat exchanger 3 and is configured to control the on/off of the pipeline at the second end of the indoor heat exchanger 3.

Thus, when the indoor heat exchanger 3 needs maintenance or replacement, by closing the first shut-off valve 31 and the second shut-off valve 32, the refrigerant in the indoor heat exchanger 3 can be sealed in the indoor heat exchanger 3, thereby omitting the step of discharging the refrigerant from the indoor heat exchanger 3 and facilitating the maintenance and replacement of the indoor heat exchanger 3.

For example, the air conditioning system 100 may be a multi-split system. The air conditioning system 100 includes a plurality of indoor units. Each indoor unit is provided with an indoor heat exchanger 3. The plurality of indoor units are connected in parallel. The first ends of the indoor heat exchangers 3 of the plurality of indoor units are communicated with the first shut-off valve 31. The second ends of the indoor heat exchangers 3 of the plurality of indoor units are communicated with the second shut-off valve 32.

It is understandable that in some embodiments, the air conditioning system 100 may include only one indoor unit.

Referring to FIGS. 17A and 17B, in some embodiments, the air conditioning system 100 further includes a gas-liquid separator 7. The gas-liquid separator 7 is arranged between the compressor 1 and the first reversing valve 2 and is configured to separate gaseous refrigerant and liquid refrigerant returning from the first reversing valve 2 to the suction port of the compressor 1 to block excessive liquid refrigerant from entering the compressor 1. As shown in FIG. 18, the gas-liquid separator 7 has a liquid inlet 71 and a gas outlet 72. The liquid inlet 71 is communicated with the fourth valve port 24. The gas outlet 72 is communicated with the suction port 11. By providing the gas-liquid separator, it can perform gas-liquid separation on the refrigerant entering the compressor 1 to reduce the amount of liquid refrigerant entering the compressor, thereby avoiding liquid slugging problems for the compressor 1 and protecting the compressor 1.

Referring to FIGS. 17A and 17B, in some embodiments, the air conditioning system 100 further includes an oil-gas separator 8. The oil-gas separator 8 is arranged between the compressor 1 and the first reversing valve 2 and is configured to separate oil droplets carried in the compressed air flowing from the compressor 1 to the first reversing valve 2. As shown in FIG. 19, the oil-gas separator 8 has an inlet 81, a gas discharge port 82, and an oil outlet 84. The inlet 81 is communicated with the discharge port 12. The gas discharge port 82 is communicated with the first valve port 21. The oil outlet 84 is communicated with the suction port 11. By providing the oil-gas separator 8, it can separate the oil droplets carried in the compressed air flowing from the compressor 1 to the first reversing valve 2, to reduce the gas content in the oil returning to the compressor 1, thereby reducing the impact of gas on the compressor 1, which can improve the protection of the compressor 1 and improve the stability and reliability of the air conditioning system 100.

Referring to FIGS. 17A and 17B, in some embodiments, the air conditioning system 100 further includes an oil return pressure reducer 83. The oil return pressure reducer 83 is located between the compressor 1 and the oil outlet 84 of the oil-gas separator 8. The oil return pressure reducer 83 is configured to return the liquid separated from the oil-gas separator 8 to the suction port 11 of the compressor 1.

Referring to FIGS. 17A and 17B, in some embodiments, the air conditioning system 100 further includes an outdoor fan 46. One side of the outdoor heat exchanger assembly may be provided with an outdoor fan 46. The outdoor fan 46 is configured to increase the airflow velocity near the outdoor heat exchanger assembly to improve the heat exchange efficiency of the outdoor heat exchanger assembly 4.

In some embodiments, as shown in FIGS. 17A and 17B, the air conditioning system 100 further includes a controller 110. The controller 110 is configured to: detect whether the air conditioning system 100 satisfies a defrost start condition; if the defrost start condition is satisfied, adjust the operating mode of the air conditioning system 100 to the first defrosting mode to defrost the first part 41; detect whether defrosting of the first part 41 is complete; if the defrosting of the first part 41 is complete, adjust the operating mode of the air conditioning system 100 to the second defrosting mode to defrost the second part 42; detect whether defrosting of the second part 42 is complete; if the defrosting of the second part 42 is complete, control the air conditioning system 100 to exit the second defrosting mode. In some embodiments, the first part 41 and the second part 42 may be provided with outdoor fans 46 respectively.

It is understandable that when the air conditioning system 100 needs defrosting, it can defrost the first part 41 first and then the second part 42, thereby alternately defrosting the first part 41 and the second part 42. In this case, the refrigerant in the indoor heat exchanger 3 can maintain high temperature and high pressure to continue heating the indoors, which is beneficial for maintaining the indoor temperature.

Based on the structure of the above air conditioning system 100 and the function of the controller 110, some embodiments of the present disclosure provide a defrosting method for the air conditioning system 100. The defrosting method for an air conditioning system 100 of some embodiments of the present disclosure is described below.

Referring to FIG. 21, in some embodiments, the defrosting method of the air conditioning system 100 includes steps S1A to S14A.

In step S1A, the air conditioning system 100 starts operating.

In step S2A, relevant temperature values and pressure values during the operation of the air conditioning system 100 are collected.

In some embodiments, as shown in FIGS. 17A and 17B, the air conditioning system 100 further includes an outdoor temperature sensor 9, a first temperature sensor 411, a second temperature sensor 422, a third temperature sensor 412, a first pressure sensor 111, a second pressure sensor 121, and a fourth temperature sensor 122.

For example, the outdoor temperature sensor 9 is configured to detect the outdoor ambient temperature Ta.

For example, the first temperature sensor 411 is configured to detect the pipeline temperature Te near the second end 4B of the outdoor heat exchanger assembly 4.

For example, the second temperature sensor 422 is configured to detect the pipeline temperature Tg1 near the first end 4A of the outdoor heat exchanger assembly 4.

For example, the third temperature sensor 412 is configured to detect the pipeline temperature Tg2 between the first part 41 and the second part 42.

For example, the first pressure sensor 111 is configured to detect the suction pressure Ps of the compressor 1.

For example, the second pressure sensor 121 is configured to detect the discharge pressure Pd of the compressor 1.

For example, the fourth temperature sensor 122 is configured to detect the discharge temperature Td of the compressor 1.

For example, the above various sensors are all coupled to the controller 110. The controller 110 can obtain various temperature values and pressure values through the above various sensors.

For example, in step S2A, the relevant temperature values include the outdoor ambient temperature Ta, the pipeline temperature Te near the second end 4B of the outdoor heat exchanger assembly 4, the pipeline temperature Tg1 near the first end 4A of the outdoor heat exchanger assembly 4, the pipeline temperature Tg2 between the first part 41 and the second part 42, and the discharge temperature Td of the compressor 1. The relevant pressure values include the suction pressure Ps of the compressor 1 and the discharge pressure Pd of the compressor 1.

It is understandable that by obtaining the above parameters, the air conditioning system can determine whether heating is currently needed based on these parameters, which can improve the sensitivity and intelligence of the air conditioning system during operation and is beneficial to improving user experience.

In step S3A, detect whether the air conditioning system 100 needs to perform heating.

If yes, proceed to step S4A. If no, proceed to step S5A.

In step S4A, the air conditioning system 100 operates in the heating mode.

In step S5A, the air conditioning system 100 operates in the cooling mode.

In step S6A, detect whether the air conditioning system 100 satisfies the defrost start condition.

If no, repeat step S4A. If yes, proceed to step S7A.

In some embodiments, the defrost start condition in step S6A includes: Ta≤a, Te≤b, and the cumulative heating time reaches a first preset duration.

a and b are both preset values.

In some embodiments, −7° C.<a<7° C. For example, the threshold a for the outdoor ambient temperature Ta can be −6° C., −5° C., −4° C., −3° C., −2° C., −1° C., 0° C., 1° C., 2° C., 3° C., 4° C., 5° C., or 6° C., etc.

In some embodiments, −5° C.≤b≤0° C. For example, b can be −5° C., −4° C., −3° C., −2° C., −1° C., or 0° C., etc.

In some embodiments, the first preset duration ≥10 minutes. For example, the value of the first preset duration can be 10 minutes, 11 minutes, 12 minutes, 13 minutes, or 14 minutes, etc.

In step S7A, the operating mode of the air conditioning system 100 is adjusted to the first defrosting mode.

In some embodiments, step S7A includes: adjusting the opening degree of the third throttle valve 43 so that the discharge superheat Tdsh of the compressor 1≥e, where e is a preset value.

For example, Tdsh=Td−Tcpd (for example, Tcpd is the saturation temperature corresponding to the discharge pressure Pd).

In some embodiments, 20° C.≤e≤40° C. For example, e can be 20° C., 25° C., 30° C., 35° C., or 40° C., etc.

As set above, the accuracy of controlling the opening degree of the third throttle valve 43 can be improved, which is beneficial to improving the reliability of the air conditioning system 100.

In step S8A, the air conditioning system 100 operates in the first defrosting mode.

It is understandable that when the air conditioning system 100 operates in the first defrosting mode, it can defrost the first part 41, and the indoor heat exchanger 3 can normally heat the indoors.

In some implementations, when the air conditioning system 100 operates in the first defrosting mode, the first reversing valve 2 never reverses, which can reduce the power consumption of the air conditioning system 100.

In some embodiments, the first defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 to defrost the first part 41, and the defrosting effect is significant.

In step S9A, detect whether defrosting of the first part is complete.

If no, repeat step S8A. If yes, proceed to step S10A.

It should be noted that when the connection method between the first part 41 and the second part 42 in the outdoor heat exchanger assembly 4 changes, the condition for the completion of defrosting the first part 41 in step S9A also changes accordingly.

For example, when the third valve port 23 is communicated with the first end of the second part 42, and the second end of the indoor heat exchanger 3 is communicated with the first end of the first part 41, the condition for the completion of defrosting the first part 41 in step S9A includes: Tg2≥f and lasts for a second preset duration, where f is a preset value.

For example, when the third valve port 23 is communicated with the first end of the first part 41, and the second end of the indoor heat exchanger 3 is communicated with the first end of the second part 42, the condition for the completion of defrosting the first part 41 in step S9A includes: Tg1≥f and lasts for a second preset duration, where f is a preset value.

In some embodiments, 10° C.≤f≤25° C. For example, f can be 10° C., 15° C., 18° C., 22° C., or 25° C., etc.

In some embodiments, 5 s≤the second preset duration ≤30 s. For example, the second preset duration can be 5 s, 10 s, 20 s, 25 s, or 30 s, etc.

Thus, the air conditioning system 100 can exit the first defrosting mode in time when the end condition of the first defrosting mode is satisfied, which is beneficial to improving the intelligence and reliability of the air conditioning system 100.

In step S10A, the air conditioning system is controlled to exit the first defrosting mode.

In step S11A, the operating mode of the air conditioning system is adjusted to the second defrosting mode.

In some embodiments, step S11A includes: adjusting the opening degree of the third throttle valve 43 so that the discharge superheat Tdsh of the compressor 1≥e, where e is a preset value.

In some embodiments, Tdsh=Td−Tcpd (for example, Tcpd is the saturation temperature corresponding to the discharge pressure Pd).

In some embodiments, 20° C.≤e≤40° C. For example, e can be 20° C., 25° C., 30° C., 35° C., or 40° C., etc.

As set above, the accuracy of controlling the opening degree of the third throttle valve 43 can be improved, which is beneficial to improving the reliability of the air conditioning system 100.

In step S12A, the air conditioning system 100 operates in the second defrosting mode.

It is understandable that when the air conditioning system 100 operates in the second defrosting mode, it can defrost the second part 42, and the indoor heat exchanger 3 can normally heat the indoors.

In some embodiments, when the air conditioning system 100 operates in the second defrosting mode, the first reversing valve 2 never reverses, which can reduce the power consumption of the air conditioning system 100.

In some embodiments, the second defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 to defrost the second part 42, and the defrosting effect is significant.

In some embodiments, when the first part 41 is located directly above the second part 42, during the defrosting process of the outdoor heat exchanger assembly 4, by defrosting the first part 41 first, the defrosting water on the first part 41 flows to the second part 42 and melts part of the frost on the second part 42. After the defrosting of the first part 41 is completed, the second part 42 is then defrosted, which is beneficial to ensuring the defrosting effect of the outdoor heat exchanger assembly 4. Moreover, it can prevent the situation where if the defrosting of the second part 42 is complete first and then the first part 41 is defrosted, the defrosting water droplets from the first part 41 fall onto the second part 42 which is acting as an evaporator, to avoid icing on the second part 42 and improve the defrosting effect of the second part 42.

In step S13A, detect whether defrosting of the second part is complete.

If no, repeat step S12A. If yes, proceed to step S14A.

It should be noted that when the connection method between the first part 41 and the second part 42 in the outdoor heat exchanger assembly 4 changes, the condition for the completion of defrosting the second part 42 in step S13A also changes accordingly.

For example, when the third valve port 23 is communicated with the first end of the second part 42, and the second end of the indoor heat exchanger 3 is communicated with the first end of the first part 41, the condition for the completion of defrosting the second part 42 in step S13A includes: Tg1≥f and lasts for a first preset duration.

For example, when the third valve port 23 is communicated with the first end of the first part 41, and the second end of the indoor heat exchanger 3 is communicated with the first end of the second part 42, the condition for the completion of defrosting the second part 42 in step S13A includes: Tg2≥f and lasts for a first preset duration.

In some embodiments, 10° C.≤f≤25° C. For example, the temperature f at the second end of the second part 42 can be 10° C., 11° C., 12° C., 13° C., 14° C., 15° C., 16° C., 17° C., 18° C., 19° C., 20° C., 21° C., 22° C., 23° C., 24° C., or 25° C., etc.

In some embodiments, 5 seconds≤the first preset duration≤30 seconds. For example, the first preset duration can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, or 30 seconds, etc.

Thus, the air conditioning system 100 can exit the second defrosting mode in time when the end condition of the second defrosting mode is satisfied, which is beneficial to improving the intelligence and reliability of the air conditioning system 100.

In step S14A, the air conditioning system is controlled to exit the second defrosting mode, and the air conditioning system 100 is controlled to operate in the heating mode.

It is understandable that when the air conditioning system 100 satisfies the end condition of the second defrosting mode, it can exit the second defrosting mode in time and switch to the normal heating mode, providing users with normal heating function, which is beneficial to improving the intelligence and reliability of the air conditioning system 100 and improving customer experience.

In some embodiments, when defrosting the first part 41, the indoor fan of the air conditioning system 100 is controlled to stop operating or operate at the lowest wind speed. This setting can ensure that the refrigerant flowing out of the indoor heat exchanger 3 has waste heat in the first defrosting mode, thereby ensuring the defrosting efficiency of the first part 41.

In other embodiments, different from the previous embodiment, the controller 110 is configured to: detect whether the air conditioning system 100 reaches the defrost start condition; if the defrost start condition is reached, adjust the operating mode of the air conditioning system 100 to the second defrosting mode to defrost the second part 42; detect whether defrosting of the second part 42 is complete; if the defrosting of the second part 42 is complete, adjust the operating mode of the air conditioning system 100 to the first defrosting mode to defrost the first part 41; detect whether defrosting of the first part 41 is complete; if the defrosting of the first part 41 is complete, control the air conditioning system 100 to exit the first defrosting mode.

It is understandable that when the air conditioning system 100 needs defrosting, it can defrost the second part 42 first and then the first part 41, thereby alternately defrosting the first part 41 and the second part 42. In this case, the refrigerant in the indoor heat exchanger 3 can maintain high temperature and high pressure to continue heating the indoors, which is beneficial for maintaining the indoor temperature.

Based on the structure of the above air conditioning system 100 and the function of the controller 110, some embodiments of the present disclosure provide another defrosting method for the air conditioning system 100.

Referring to FIG. 21, in some embodiments, the defrosting method of the air conditioning system 100 includes steps S1B to S14B.

In step S1B, the air conditioning system 100 starts operating.

In step S2B, relevant temperature values and pressure values during the operation of the air conditioning system 100 are collected.

In some embodiments, in step S2B, the relevant temperature values include the outdoor ambient temperature Ta, the gas pipe temperature Te at the first end of the first part 41, the gas pipe temperature Tg1 at the first end of the second part 42, the gas pipe temperature Tg2 at the second end of the first part 41, and the discharge temperature Td of the compressor. The relevant pressure values include the suction pressure Ps of the compressor 1 and the discharge pressure Pd of the compressor 1.

It is understandable that by obtaining the above parameters, the air conditioning system can determine whether heating is currently needed based on these parameters, which can improve the sensitivity and intelligence of the air conditioning system during operation and is beneficial to improving user experience.

In step S3B, detect whether the air conditioning system 100 needs to perform heating.

If yes, proceed to step S4B. If no, proceed to step S5B.

In step S4B, the air conditioning system 100 operates in the heating mode.

In step S5B, the air conditioning system 100 operates in the cooling mode.

In step S6B, detect whether the air conditioning system 100 satisfies the defrost start condition.

If no, repeat step S4B. If yes, proceed to step S7B.

In some embodiments, the defrost start condition in step S6B includes: Ta≤a, Te≤b, and the cumulative heating time reaches a first preset duration.

a and b are both preset values.

In some embodiments, −7° C.<a<7° C. For example, the threshold a for the outdoor ambient temperature Ta can be −6° C., −5° C., −4° C., −3° C., −2° C., −1° C., 0° C., 1° C., 2° C., 3° C., 4° C., 5° C., or 6° C., etc.

In some embodiments, −5° C.≤b≤0° C. For example, b can be −5° C., −4° C., −3° C., −2° C., −1° C., or 0° C., etc.

In some embodiments, the first preset duration ≥10 minutes. For example, the first preset duration can be 10 minutes, 11 minutes, 12 minutes, 13 minutes, or 14 minutes, etc.

In step S7B, the operating mode of the air conditioning system is adjusted to the second defrosting mode.

In some embodiments, step S7B includes: adjusting the opening degree of the third throttle valve 43 so that the discharge superheat Tdsh of the compressor 1≥e, where e is a preset value.

For example, Tdsh=Td−Tcpd (for example, Tcpd is the saturation temperature corresponding to the discharge pressure Pd).

As set above, the accuracy of controlling the opening degree of the third throttle valve 43 can be improved, which is beneficial to improving the reliability of the air conditioning system 100.

In some embodiments, 20° C.≤e≤40° C. For example, e can be 20° C., 25° C., 30° C., 35° C., or 40° C., etc.

In step S8B, the air conditioning system 100 operates in the second defrosting mode.

It is understandable that when the air conditioning system 100 operates in the second defrosting mode, it can defrost the second part 42, and the indoor heat exchanger 3 can normally heat the indoors.

In some embodiments, when the air conditioning system 100 operates in the second defrosting mode, the first reversing valve 2 never reverses, which can reduce the power consumption of the air conditioning system 100.

In some embodiments, the second defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 to defrost the second part 42, and the defrosting effect is significant.

In step S9B, detect whether defrosting of the second part 42 is complete.

If no, repeat step S8B. If yes, proceed to step S10B.

It should be noted that when the connection method between the first part 41 and the second part 42 in the outdoor heat exchanger assembly 4 changes, the condition for the completion of defrosting the second part 42 in step S9B also changes accordingly.

For example, when the third valve port 23 is communicated with the first end of the second part 42, and the second end of the indoor heat exchanger 3 is communicated with the first end of the first part 41, the condition for the completion of defrosting the second part 42 in step S9B includes: Tg1≥f and lasts for a first preset duration.

For example, when the third valve port 23 is communicated with the first end of the first part 41, and the second end of the indoor heat exchanger 3 is communicated with the first end of the second part 42, the condition for the completion of defrosting the second part 42 in step S9B includes: Tg2≥f and lasts for a first preset duration.

In some embodiments, 10° C.≤f≤25° C. For example, the temperature f at the second end of the second part 42 can be 10° C., 11° C., 12° C., 13° C., 14° C., 15° C., 16° C., 17° C., 18° C., 19° C., 20° C., 21° C., 22° C., 23° C., 24° C., or 25° C., etc.

In some embodiments, 5 seconds≤the first preset duration≤30 seconds. For example, the first preset duration can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, or 30 seconds, etc.

Thus, the air conditioning system 100 can exit the second defrosting mode in time when the end condition of the second defrosting mode is satisfied, which is beneficial to improving the intelligence and reliability of the air conditioning system 100.

In step S10B, the air conditioning system is controlled to exit the second defrosting mode.

In step S11B, the operating mode of the air conditioning system is adjusted to the first defrosting mode.

In some embodiments, step S11B includes: adjusting the opening degree of the third throttle valve 43 so that the discharge superheat Tdsh of the compressor 1≥e, where e is a preset value.

In some embodiments, Tdsh=Td−Tcpd (for example, Tcpd is the saturation temperature corresponding to the discharge pressure Pd).

In some embodiments, 20° C.≤e≤40° C. For example, e can be 20° C., 25° C., 30° C., 35° C., or 40° C., etc.

As set above, the accuracy of controlling the opening degree of the third throttle valve 43 can be improved, which is beneficial to improving the reliability of the air conditioning system 100.

In step S12B, the air conditioning system 100 operates in the first defrosting mode.

It is understandable that when the air conditioning system 100 operates in the first defrosting mode, it can defrost the first part 41, and the indoor heat exchanger 3 can normally heat the indoors.

In some embodiments, when the air conditioning system 100 operates in the first defrosting mode, the first reversing valve 2 never reverses, which can reduce the power consumption of the air conditioning system 100.

In some embodiments, the first defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 to defrost the first part 41, and the defrosting effect is significant.

In step S13B, detect whether defrosting of the first part is complete.

If no, repeat step S12B. If yes, proceed to step S14B.

It should be noted that when the connection method between the first part 41 and the second part 42 in the outdoor heat exchanger assembly 4 changes, the condition for the completion of defrosting the second part 42 in step S13B also changes accordingly.

For example, when the third valve port 23 is communicated with the first end of the second part 42, and the second end of the indoor heat exchanger 3 is communicated with the first end of the first part 41, the condition for the completion of defrosting the second part 42 in step S13B includes: Tg2≥f and lasts for a second preset duration, where f is a preset value.

For example, when the third valve port 23 is communicated with the first end of the first part 41, and the second end of the indoor heat exchanger 3 is communicated with the first end of the second part 42, the condition for the completion of defrosting the second part 42 in step S13B includes: Tg1≥f and lasts for a second preset duration, where f is a preset value.

In some embodiments, 10° C.≤f≤25° C. For example, f can be 10° C., 15° C., 18° C., 22° C., or 25° C., etc.

In some embodiments, 5 s≤the second preset duration≤30 s. For example, the second preset duration can be 5 s, 10 s, 20 s, 25 s, or 30 s, etc.

Thus, the air conditioning system 100 can exit the first defrosting mode in time when the end condition of the first defrosting mode is satisfied, which is beneficial to improving the intelligence and reliability of the air conditioning system 100.

In step S14B, the air conditioning system is controlled to exit the first defrosting mode, and the air conditioning system 100 is controlled to operate in the heating mode.

It is understandable that when the air conditioning system 100 satisfies the end condition of the first defrosting mode, it exits the first defrosting mode in time and switches to the heating mode, which is beneficial to improving the intelligence and reliability of the air conditioning system 100 and improving customer experience.

In some embodiments, the controller 110 of some embodiments of the present disclosure is configured to: adjust the operating mode of the air conditioning system 100 to the first defrosting mode to defrost the first part 41; control the first fan 45 to stop operating and control the second fan 47 to operate normally; if the defrosting of the first part 41 is complete, adjust the operating mode of the air conditioning system 100 to the second defrosting mode to defrost the second part 42; control the second fan 47 to stop operating and control the first fan 45 to operate normally; if the defrosting of the second part 42 is complete, control the air conditioning system 100 to exit the second defrosting mode.

Some embodiments of the present disclosure also provide a defrost control method for the air conditioning system 100. As shown in FIG. 22, the defrost control method includes steps S100A to S700A.

In step S100A, the operating mode of the air conditioning system 100 is adjusted to the first defrosting mode to defrost the first part 41.

In step S200A, the first fan 45 is controlled to stop operating, and the second fan 47 is controlled to operate.

In step S300A, detect whether the first part 41 is defrosted.

In step S400A, if the defrosting of the first part 41 is complete, the operating mode of the air conditioning system 100 is adjusted to the second defrosting mode to defrost the second part 42.

In step S500A, the second fan 47 is controlled to stop operating, and the first fan 45 is controlled to operate.

In step S600A, detect whether defrosting of the second part 42 is complete.

In step S700A, if the defrosting of the second part 42 is complete, the air conditioning system 100 is controlled to exit the second defrosting mode.

Below, with reference to FIG. 23, the above defrost control method is supplemented. After adjusting the operating mode of the air conditioning system 100 to the first defrosting mode, the above defrost control method further includes steps S101A to S108A.

In step S101A, the air conditioning system 100 starts defrosting.

In step S102A, the operating mode of the air conditioning system 100 is adjusted to the first defrosting mode.

In step S103A, the value Tg1 of the first temperature sensor is detected.

In step S104A, determine whether the air conditioning system 100 satisfies Tg1≥Tgo1 (Tgo1 is a preset value, Tgo1 is the temperature target threshold for the air conditioning system 100 to exit the first defrosting mode) and maintains for time m1 (m1 is a preset value, set according to different air conditioning systems or customer needs).

In step S105A, if the determination result is yes, the operating mode of the air conditioning system is adjusted to the second defrosting mode.

In step S106A, detect the value Tg2 of the second temperature sensor.

In step S107A, determine whether the air conditioning system 100 satisfies Tg2≥Tgo2 (Tgo2 is a preset value, Tgo2 is the temperature target threshold for the air conditioning system 100 to exit the second defrosting mode) and maintains for time m2 (m2 is a preset value, set according to different air conditioning systems or customer needs).

In step S108A, if the determination result is yes, the operating mode of the air conditioning system is controlled to exit the second defrosting mode.

In some embodiments, the controller 110 of some embodiments of the present disclosure is configured to: adjust the operating mode of the air conditioning system 100 to the second defrosting mode to defrost the second part 42; control the second fan 47 to stop operating and control the first fan 45 to operate normally; if the defrosting of the second part 42 is complete, adjust the operating mode of the air conditioning system 100 to the first defrosting mode to defrost the first part 41; control the first fan 45 to stop operating and control the second fan 47 to operate normally; if the defrosting of the first part 41 is complete, control the air conditioning system 100 to exit the second defrosting mode.

Some embodiments of the present disclosure also provide a defrost control method for the air conditioning system 100. As shown in FIG. 24, the defrost control method includes steps S100B to S700B.

In step S100B, the operating mode of the air conditioning system 100 is adjusted to the second defrosting mode to defrost the second part 42.

In step S200B, the second fan 47 is controlled to stop operating, and the first fan 45 is controlled to operate.

In step S300B, detect whether defrosting of the second part 42 is complete.

In step S400B, if the defrosting of the second part 42 is complete, the operating mode of the air conditioning system 100 is adjusted to the first defrosting mode to defrost the first part 41.

In step S500B, the first fan 45 is controlled to stop operating, and the second fan 47 is controlled to operate.

In step S600B, detect whether the first part 41 is defrosted.

In step S700B, if the defrosting of the first part 41 is complete, the air conditioning system 100 is controlled to exit the first defrosting mode.

Below, with reference to FIG. 25, the above defrost control method is supplemented. After adjusting the operating mode of the air conditioning system 100 to the second defrosting mode, the above defrost control method further includes steps S101B to S108B.

In step S101B, the air conditioning system 100 starts defrosting.

In step S102B, the operating mode of the air conditioning system 100 is adjusted to the second defrosting mode.

In step S103B, detect the value Tg2 of the second temperature sensor.

In step S104B, determine whether the air conditioning system 100 satisfies Tg2≥Tgo2 (Tgo2 is a preset value, Tgo2 is the temperature target threshold for the air conditioning system 100 to exit the second defrosting mode) and maintains for time m2 (m2 is a preset value, set according to different air conditioning systems or customer needs).

In step S105B, if the determination result is yes, the operating mode of the air conditioning system is adjusted to the first defrosting mode.

In step S106B, the value Tg1 of the first temperature sensor is detected.

In step S107B, determine whether the air conditioning system 100 satisfies Tg1≥Tgo1 (Tgo1 is a preset value, Tgo1 is the temperature target threshold for the air conditioning system 100 to exit the first defrosting mode) and maintains for time m1 (m1 is a preset value, set according to different air conditioning systems or customer needs).

In step S108B, if the determination result is yes, the operating mode of the air conditioning system is controlled to exit the first defrosting mode.

With the above settings, the first part 41 and the second part 42 can be defrosted alternately, and uninterrupted heating can be provided to the indoors during the defrosting process, improving the user experience of the air conditioning system 100. Moreover, when defrosting the first part 41, the first fan 45 stops operating, which can prevent the first fan 45 from blowing cold air to the first part 41, thereby maintaining the temperature of the first part 41 and helping to improve the defrosting speed of the first part 41; the second fan 47 operates, allowing the second part 42 to normally exchange heat with the outdoor air, thereby improving the heating efficiency of the air conditioning system 100. Moreover, when defrosting the second part 42, the second fan 47 stops operating, which can prevent the second fan 47 from blowing cold air to the second part 42, thereby maintaining the temperature of the second part 42 and helping to improve the defrosting speed of the second part 42; the first fan 45 operates, allowing the first part 41 to normally exchange heat with the outdoor air to absorb heat, thereby improving the heating efficiency of the air conditioning system 100.

In some embodiments, the above adjusting the operating mode of the air conditioning system 100 to the first defrosting mode includes: controlling the indoor unit fan 30 to stop operating, and/or, adjusting the operating mode of the air conditioning system 100 to the second defrosting mode further includes: controlling the indoor unit fan 30 to stop operating.

Through the above settings, the heat released by the refrigerant to the indoors can be reduced, so that more heat can be used to defrost the first part 41 or the second part 42, thereby improving the defrosting speed of the first part 41 or the second part 42.

In some embodiments, adjusting the operating mode of the air conditioning system 100 to the first defrosting mode further includes: controlling the rotational speed of the indoor unit fan 30 to a first preset rotational speed; and/or, adjusting the operating mode of the air conditioning system 100 to the second defrosting mode further includes: controlling the rotational speed of the indoor unit fan 30 to the first preset rotational speed; wherein the first preset rotational speed is less than the maximum rotational speed of the indoor unit fan.

With the above settings, the heat released by the refrigerant to the indoors can be reduced, ensuring the indoor air supply temperature, thereby improving indoor temperature comfort, and allowing more heat to be used to defrost the first part 41 or the second part 42, thereby improving the defrosting speed of the first part 41 or the second part 42.

In some embodiments, as shown in FIGS. 2, 3, and 4, the air conditioning system 100 further includes a second pressure sensor 121. The second pressure sensor 121 is arranged at the discharge port 12 of the compressor 1 and is configured to detect the discharge pressure Pd at the discharge port 12.

In some embodiments, after controlling the rotational speed of the indoor unit fan 30 to the first preset rotational speed n, and before the air conditioning system 100 exits the defrosting mode, the defrost control method further includes: detecting the discharge pressure Pd at the discharge port 12; comparing the discharge pressure Pd with a first threshold pressure Pdomax and a second threshold pressure Pdomin respectively, and obtaining a comparison result; if Pd≥Pdomax, adjusting the rotational speed of the indoor unit fan 30 to n1, and n1>n; if Pd≤Pdomin, adjusting the rotational speed of the indoor unit fan to n2, and 0≤n2<n; if Pdomin<Pd<Pdomax, maintaining the rotational speed of the indoor unit fan at n. Wherein, n>0, Pdomin<Pdomax.

In some embodiments, 2.8 MPa≤Pdomax≤3.5 MPa. For example, Pdomax can be 2.8 MPa, 2.9 MPa, 3.1 MPa, 3.3 MPa, 3.5 MPa, etc.

In some embodiments, 1.6 MPa≤Pdomin≤1.9 MPa. For example, Pdomin can be 1.6 MPa, 1.65 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, etc.

Below, with reference to FIG. 26, the above defrost control method is further explained. The defrost control method further includes steps S1 to S10.

In step S1, the air conditioning system 100 starts defrosting.

In step S2, the rotational speed of the indoor unit fan 30 is controlled to be the first preset rotational speed n.

In step S3, detect the discharge pressure Pd at the discharge port 12.

In step S4, determine whether Pd≥Pdomax is satisfied. For example, the size of Pd is compared with the size of the first threshold pressure Pdomax to determine whether Pd≥Pdomax is satisfied.

In step S5, if yes, adjust the rotational speed of the indoor unit fan 30 to n1.

In step S6, if no, determine whether Pd≤Pdomin is satisfied. For example, the size of Pd is compared with the size of the second threshold pressure Pdomin to determine whether Pd≤Pdomin is satisfied.

In step S7, if yes, adjust the rotational speed of the indoor unit fan 30 to n2.

In step S8, if no, that is, Pdomin<Pd<Pdomax, maintain the rotational speed of the indoor unit fan 30 at n.

In step S9, determine whether the air conditioning system 100 satisfies the condition for exiting the defrosting mode.

In step S10, if yes, control the air conditioning system 100 to exit defrosting; if no, repeat step S3.

With the above settings, the rotational speed of the indoor unit fan 30 can be automatically controlled according to the discharge pressure Pd at the discharge port 12. While ensuring the defrosting effect on the first part 41 or the second part 42, more heat can be used to heat the indoors, which is beneficial to improving indoor temperature comfort.

In some embodiments, as shown in FIG. 2, the air conditioning system 100 further includes a third pressure sensor 304. The third pressure sensor 304 is arranged at the second end of the second part 42 and is configured to detect the pressure at the second end of the second part 42.

After the air conditioning system 100 switches from the first defrosting mode to the second defrosting mode, as shown in FIG. 27, the defrost control method further includes controlling the opening degree of the sixth throttle valve 53. The control method of the air conditioning system 100 for the opening degree of the sixth throttle valve 53 includes steps S10A to S120A.

In step S10A, the air conditioning system 100 starts defrosting the second part 42.

In step S20A, adjust the sixth throttle valve 53 to an initial valve opening degree (e.g., the initial valve opening degree is a preset value, which can be set according to the actual situation).

In step S30A, detect the value Pdef of the third pressure sensor 304 and compare it with Pdefmax (Pdefmax is the target maximum threshold corresponding to the third pressure sensor 304).

In step S40A, determine whether Pdef≥Pdefmax is satisfied.

In step S50A, if yes, reduce the opening degree of the sixth throttle valve 53. In this way, the refrigerant flow rate entering the second part 42 can be reduced, the refrigerant pressure entering the second part 42 can be lowered, the discharge pressure at the discharge port 12 can be increased, and the indoor air supply temperature can be increased.

In step S60A, if no, determine whether Pdef≤Pdefmin is satisfied. For example, the size of Pdef is compared with the size of Pdefmin (Pdefmin is the target minimum threshold corresponding to the third pressure sensor 304) to determine whether Pdef≤Pdefmin is satisfied.

In step S70A, if yes, increase the opening degree of the sixth throttle valve 53. In this way, the refrigerant flow rate entering the second part 42 can be increased, the refrigerant pressure entering the second part 42 can be increased, the temperature of the condenser during defrosting can be increased, and the defrosting speed can be increased.

In step S80A, if no, that is, Pdefmin<Pdef<Pdefmax, maintain the opening degree of the sixth throttle valve 53 unchanged.

In step S90A, determine whether the air conditioning system satisfies the condition for exiting the defrosting mode.

In step S110A, if yes, the air conditioning system 100 exits the defrosting mode, and the sixth throttle valve 53 is adjusted to the fully closed state.

In step S120A, if no, repeat step S30A.

For example, the initial valve opening degree can be set to 100%, which can increase the refrigerant flow rate entering the second part 42 and speed up the defrosting speed; the initial valve opening degree can also be set to 50% or less, which can reduce the refrigerant flow rate entering the second part 42, increase the discharge pressure at the discharge port 12 of the compressor 1, and thus increase the indoor air supply temperature.

For example, Pdefmax is a preset value and can be set according to the actual situation.

For example, the value of Pdefmax can be 1.0 MPa (corresponding to a saturation temperature of 10° C.).

For example, Pdefmin is a preset value and can be set according to the actual situation.

For example, the value of Pdefmin can be 1.0 MPa (corresponding to a saturation temperature of 4° C.).

In some embodiments, the above third pressure sensor 304 can also be replaced with a temperature sensor, and the pressure at the second end of the second part 42 is obtained by detecting the temperature and converting it. This can avoid the need for a third pressure sensor 304 with high cost and reduce the production cost of the air conditioning system 100.

The above mainly describes the solutions provided by the embodiments of the present disclosure from the perspective of the air conditioning system 100. It can be understood that in order to achieve the above functions, the air conditioning system 100 includes hardware structures and/or software modules corresponding to each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of the examples described in the embodiments disclosed herein, the present disclosure can be implemented in hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professionals can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of the present disclosure.

Those skilled in the art will understand that the scope of the present disclosure is not limited to the specific embodiments above, and certain elements of the embodiments can be modified and replaced without departing from the spirit of the present disclosure. The scope of the present disclosure is limited by the appended claims.

Claims

1. An air conditioning system, having a defrosting mode, a cooling mode, and a heating mode, the air conditioning system comprising:

a compressor, comprising a suction port and a discharge port;

an indoor heat exchanger, a first end of the indoor heat exchanger being communicated with one of the suction port and the discharge port;

an outdoor unit, comprising: a housing, wherein a cavity is defined within the housing;

an outdoor heat exchanger assembly, comprising a first part and a second part;

a partition plate, disposed within the cavity and partitioning the cavity into a first space and a second space independent of each other;

a first fan, located in the first space with the first part, the first fan being configured to increase an airflow velocity near the first part;

a second fan, located in the second space with the second part, the second fan being configured to increase an airflow velocity near the second part; and

a defrost pipeline, communicated with the discharge port;

wherein, the defrosting mode comprises a first defrosting mode and a second defrosting mode;

in a case where the air conditioning system operates in the first defrosting mode, the defrost pipeline is configured to transmit a refrigerant discharged from the discharge port to one of the first part and the second part;

in a case where the air conditioning system operates in the second defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the other of the first part and the second part;

wherein, in a case where the air conditioning system operates in the first defrosting mode to defrost the first part, the first fan stops operating, and the second fan operates normally, so that high-temperature and high-pressure gaseous refrigerant discharged from the discharge port is transmitted to the first part, and a refrigerant cycle is performed between the second part and the indoor heat exchanger to heat indoor air;

in a case where the air conditioning system operates in the second defrosting mode to defrost the second part, the second fan stops operating, and the first fan operates normally, so that the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port is transmitted to the second part for condensation and heat release, the condensed refrigerant is then transmitted to the first part for evaporation and heat absorption, and then returns to the compressor, and the refrigerant cycle is performed between the first part and the indoor heat exchanger to heat indoor air.

2. The air conditioning system according to claim 1, wherein the first part is located on one side of the second part, and in a plane perpendicular to a direction from the first part towards the second part, a projection of at least a portion of the first part overlaps a projection of at least a portion of the second part.

3. The air conditioning system according to claim 1, wherein the first part and the second part are independent heat exchangers respectively.

4. The air conditioning system according to claim 1, wherein a second end of the first part is communicated with a second end of the second part, and the defrost pipeline is communicated with a pipeline between the first part and the second part;

a first end of the one of the first part and the second part is communicated with the other of the suction port and the discharge port, and a first end of the other of the first part and the second part is communicated with a second end of the indoor heat exchanger and is communicated with the defrost pipeline;

in a case where the air conditioning system operates in the first defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the first end of the one of the first part and the second part, and discharge the refrigerant from the second end of the one of the first part and the second part;

in a case where the air conditioning system operates in the second defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the second end of the other of the first part and the second part, and discharge the refrigerant from the first end of the other of the first part and the second part.

5. The air conditioning system according to claim 4, wherein the defrost pipeline comprises:

a bypass branch, a first end of the bypass branch being communicated with the discharge port; and,

a diverting branch, comprising: a first defrost branch, a first end of the first defrost branch being communicated with a second end of the bypass branch, a second end of the first defrost branch is communicated with the pipeline between the first part and the second part; and a second defrost branch, a first end of the second defrost branch being communicated with the second end of the bypass branch, a second end of the second defrost branch is communicated with the first end of the other of the first part and the second part.

6. The air conditioning system according to claim 5, wherein the defrost pipeline further comprises:

a first throttle valve, connected in series with the first defrost branch; and,

a second throttle valve, connected in series with the second defrost branch;

in a case where the air conditioning system operates in the defrosting mode, one of the first throttle valve and the second throttle valve is open, and the other of the first throttle valve and the second throttle valve is closed, to enable one of the first defrost branch and the second defrost branch and block the other of the first defrost branch and the second defrost branch.

7. The air conditioning system according to claim 6, wherein the defrost pipeline further comprises a check valve, the check valve being connected in series with a pipeline between the first throttle valve and the second end of the first defrost branch, wherein a flow direction of the check valve is a direction from the first throttle valve towards the second end of the first defrost branch, and the check valve is configured to control the refrigerant to flow from the first throttle valve to the second end of the first defrost branch and block the refrigerant from flowing from the second end of the first defrost branch to the first throttle valve.

8. The air conditioning system according to claim 1, further comprising a first reversing valve, a first valve port of the first reversing valve being communicated with the discharge port, a fourth valve port of the first reversing valve being communicated with the suction port;

wherein the first end of the indoor heat exchanger is communicated with a second valve port of the first reversing valve to communicate with the one of the suction port and the discharge port;

wherein a first end of the one of the first part and the second part is communicated with a third valve port of the first reversing valve to communicate with the other of the suction port and the discharge port.

9. The air conditioning system according to claim 1, wherein in a case where the air conditioning system operates in the first defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to a first end of the first part and discharge the refrigerant from a second end of the first part; the second fan operates normally, the first end of the first part is communicated with a second end of the indoor heat exchanger, a first end of the second part is communicated with the suction port, the second end of the first part is communicated with a second end of the second part, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air;

wherein in a case where the air conditioning system operates in the second defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the second end of the second part and discharge the refrigerant from the first end of the second part; the first end of the first part is communicated with the second end of the indoor heat exchanger, the first end of the second part is communicated with the suction port, the second end of the first part is communicated with the second end of the second part, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air.

10. The air conditioning system according to claim 1, wherein in a case where the air conditioning system operates in the first defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to a second end of the first part and discharge the refrigerant from a first end of the first part; a first end of the second part is communicated with a second end of the indoor heat exchanger, the first end of the first part is communicated with the suction port, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air;

wherein in a case where the air conditioning system operates in the second defrosting mode, the defrost pipeline is configured to transmit the refrigerant discharged from the discharge port to the first end of the second part and discharge the refrigerant from a second end of the second part;

the first end of the second part is communicated with the second end of the indoor heat exchanger, the first end of the first part is communicated with the suction port, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air.

11. The air conditioning system according to claim 1, wherein,

in a case where the air conditioning system operates in the first defrosting mode, a second end of the first part is communicated with the discharge port, a first end of the first part is communicated with the suction port, to enable refrigerant in the compressor to enter the first part from the discharge port and defrost the first part, and then return to the compressor via the suction port; a second end of the second part is communicated with a second end of the indoor heat exchanger, a first end of the second part is communicated with the suction port, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air;

in a case where the air conditioning system operates in the second defrosting mode, the second end of the second part is communicated with the discharge port, the first end of the second part is communicated with the suction port, to enable the refrigerant in the compressor to enter the second part from the discharge port and defrost the second part, and then return to the compressor via the suction port; the second end of the first part is communicated with the second end of the indoor heat exchanger, the first end of the first part is communicated with the suction port, the first end of the indoor heat exchanger is communicated with the discharge port, to enable the indoor heat exchanger to heat indoor air.

12. The air conditioning system according to claim 11, further comprising:

a fourth throttle valve, connected in a pipeline between the second end of the first part and the second end of the indoor heat exchanger;

a fifth throttle valve, connected in a pipeline between the second end of the second part and the second end of the indoor heat exchanger;

a first reversing valve, a first valve port of the first reversing valve being communicated with the discharge port, a second valve port of the first reversing valve being communicated with the first end of the indoor heat exchanger, a third valve port of the first reversing valve being communicated with the first end of the first part, a fourth valve port of the first reversing valve being communicated with the suction port;

the defrost pipeline comprises:

a first branch, a first end of the first branch being communicated with the third valve port of the first reversing valve, a second end of the first branch being communicated with the first end of the second part;

a first on-off valve, connected in series with the first branch;

a second branch, a first end of the second branch being communicated with the discharge port, a second end of the second branch being communicated with the first end of the second part;

a sixth throttle valve, connected in series with the second branch;

a third branch, a first end of the third branch being communicated with the discharge port, a second end of the third branch being communicated with a pipeline between the fourth throttle valve and the second end of the first part;

a second on-off valve, connected in series with the third branch;

a fourth branch, a first end of the fourth branch being communicated with the pipeline between the fourth throttle valve and the second end of the first part, a second end of the fourth branch being communicated with a pipeline between the fifth throttle valve and the second end of the second part;

a seventh throttle valve, connected in series with the fourth branch.

13. The air conditioning system according to claim 11, further comprising:

a fourth throttle valve, connected in a pipeline between the second end of the first part and the second end of the indoor heat exchanger;

a fifth throttle valve, connected in a pipeline between the second end of the second part and the second end of the indoor heat exchanger;

a first reversing valve, a first valve port of the first reversing valve being communicated with the discharge port, a second valve port of the first reversing valve being communicated with the first end of the indoor heat exchanger, a third valve port of the first reversing valve being communicated with the first end of the first part, a fourth valve port of the first reversing valve being communicated with the suction port;

a second reversing valve, a first port of the second reversing valve being communicated with the discharge port, a second port of the second reversing valve being communicated with the suction port, a third port of the second reversing valve being communicated with the first end of the second part;

the defrost pipeline comprises: a third branch, a first end of the third branch being communicated with the discharge port, a second end of the third branch being communicated with a pipeline between the fourth throttle valve and the second end of the first part; a second on-off valve, connected in series with the third branch; a fourth branch, a first end of the fourth branch being communicated with the pipeline between the fourth throttle valve and the second end of the first part, a second end of the fourth branch being communicated with a pipeline between the fifth throttle valve and the second end of the second part; and a seventh throttle valve, connected in series with the fourth branch.

14. The air conditioning system according to claim 11, further comprising:

a fourth throttle valve, connected in a pipeline between the second end of the first part and the second end of the indoor heat exchanger;

a fifth throttle valve, connected in a pipeline between the second end of the second part and the second end of the indoor heat exchanger;

a first reversing valve, a first valve port of the first reversing valve being communicated with the discharge port, a second valve port of the first reversing valve being communicated with the first end of the indoor heat exchanger, a third valve port of the first reversing valve being communicated with the first end of the first part, a fourth valve port of the first reversing valve being communicated with the suction port;

the defrost pipeline comprises: a first branch, a first end of the first branch being communicated with the third valve port of the first reversing valve, a second end of the first branch being communicated with the first end of the second part; a first on-off valve, connected in series with the first branch; a third branch, a first end of the third branch being communicated with the discharge port, a second end of the third branch being communicated with a pipeline between the fourth throttle valve and the second end of the first part; a second on-off valve, connected in series with the third branch; a fifth branch, a first end of the fifth branch being communicated with the discharge port, a second end of the fifth branch being communicated with a pipeline between the fifth throttle valve and the second end of the second part; an eighth throttle valve, connected in series with the fifth branch; a sixth branch, a first end of the sixth branch being communicated with the pipeline between the fourth throttle valve and the second end of the first part, a second end of the sixth branch being communicated with a pipeline between the first on-off valve and the first end of the second part; and a ninth throttle valve, connected in series with the sixth branch.

15. The air conditioning system according to claim 12, further comprising:

a first subcooling device, connected in a pipeline between the fourth throttle valve and the second end of the indoor heat exchanger, and configured to reduce a temperature of refrigerant entering the fourth throttle valve from the indoor heat exchanger; and

a second subcooling device, connected in a pipeline between the fifth throttle valve and the second end of the indoor heat exchanger, and configured to reduce a temperature of refrigerant entering the fifth throttle valve from the indoor heat exchanger.

16. The air conditioning system according to claim 1, further comprising a controller; the controller satisfies one of the following:

the controller is configured to:

if the air conditioning system satisfies a defrost start condition, adjust an operating mode of the air conditioning system to the first defrosting mode to defrost the first part;

if the defrosting of the first part is complete, adjust the operating mode of the air conditioning system to the second defrosting mode to defrost the second part; and

if the defrosting of the second part is complete, control the air conditioning system to exit the second defrosting mode;

or,

the controller is configured to:

if the air conditioning system satisfies the defrost start condition, adjust the operating mode of the air conditioning system to the second defrosting mode to defrost the second part;

detect whether the defrosting of the second part is complete;

if the defrosting of the second part is complete, adjust the operating mode of the air conditioning system to the first defrosting mode to defrost the first part; and

if the defrosting of the first part is complete, control the air conditioning system to exit the first defrosting mode.

17. The air conditioning system according to claim 1, further comprising a controller; the controller satisfies one of the following:

the controller is configured to:

adjust an operating mode of the air conditioning system to the first defrosting mode to defrost the first part;

control the first fan to stop operating and control the second fan to operate normally;

if a defrosting of the first part is complete, adjust the operating mode of the air conditioning system to the second defrosting mode to defrost the second part;

control the second fan to stop operating and control the first fan to operate; and

if a defrosting of the second part is complete, control the air conditioning system to exit the second defrosting mode;

or,

the controller is configured to:

adjust an operating mode of the air conditioning system to the second defrosting mode to defrost the second part;

control the second fan to stop operating and control the first fan to operate normally;

if a defrosting of the second part is complete, adjust the operating mode of the air conditioning system to the first defrosting mode to defrost the first part;

control the first fan to stop operating and control the second fan to operate; and

if a defrosting of the first part is complete, control the air conditioning system to exit the first defrosting mode.

18. The air conditioning system according to claim 17, further comprising an indoor unit fan;

the controller satisfies at least one of the following:

the controller is further configured to: when adjusting the operating mode of the air conditioning system to the first defrosting mode, control the indoor unit fan to stop operating;

or,

the controller is further configured to: when adjusting the operating mode of the air conditioning system to the second defrosting mode, control the indoor unit fan to stop operating.

19. The air conditioning system according to claim 17, further comprising an indoor unit fan;

the controller satisfies at least one of the following:

the controller is configured to: when adjusting the operating mode of the air conditioning system to the first defrosting mode, control a rotational speed of the indoor unit fan to be a first preset rotational speed n;

or,

the controller is configured to: when adjusting the operating mode of the air conditioning system to the second defrosting mode, control the rotational speed of the indoor unit fan to be the first preset rotational speed n;

wherein, the first preset rotational speed is less than a maximum rotational speed of the indoor unit fan.

20. The air conditioning system according to claim 19, wherein the controller is further configured to:

before the air conditioning system exits the defrosting mode, determine a discharge pressure Pd of the discharge port;

compare the discharge pressure Pd with a first threshold pressure Pdomax and a second threshold pressure Pdomin respectively to obtain a comparison result;

if the discharge pressure Pd≥the first threshold pressure Pdomax, adjust the rotational speed of the indoor unit fan to a first rotational speed n1; if the discharge pressure Pd≤the second threshold pressure Pdomin, adjust the rotational speed of the indoor unit fan to a second rotational speed n2; if the second threshold pressure Pdomin<the discharge pressure Pd<the first threshold pressure Pdomax, maintain the rotational speed of the indoor unit fan at the first preset rotational speed n;

wherein, the first rotational speed n1>the first preset rotational speed n, 0≤the second rotational speed n2<the first preset rotational speed n, the first preset rotational speed n>0 and the second threshold pressure Pdomin<the first threshold pressure Pdomax.