REFRIGERATION CYCLE DEVICE
A refrigeration cycle device includes an outside evaporator, an inside evaporator, an evaporating pressure adjusting valve, a charging port, a pressure change buffer. The outside evaporator exchanges heat between a refrigerant flowing out of a heater and an outside air. The inside evaporator exchanges heat between the refrigerant flowing out of the outside evaporator and a heat-exchange target medium. The evaporating pressure adjusting valve is disposed at a position downstream of the inside evaporator and adjusts an evaporating pressure of the refrigerant in the inside evaporator. The charging port is disposed at a position downstream of the evaporating pressure adjusting valve. The pressure change buffer is disposed between the evaporating pressure adjusting valve and the charging port and defines a buffer space.
The present application is a continuation application of International Patent Application No. PCT/JP2018/041810 filed on Nov. 12, 2018, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2017-233196 filed on Dec. 5, 2017. The entire disclosures of all of the above applications are incorporated herein by reference.
TECHNICAL FIELDThe present disclosure relates to a refrigeration cycle device.
BACKGROUND ARTA refrigeration cycle device includes a compressor, an outside evaporator, an inside evaporator, and an evaporating pressure adjusting valve. The evaporating pressure adjusting valve is configured to adjust an evaporating pressure of a refrigerant in the inside evaporator as a value equal to or higher than a frost restriction pressure to restrict a frost from generating on the inside evaporator. The evaporating pressure adjusting valve is configured to adjust an opening degree of the valve with a mechanical means.
SUMMARYA refrigeration cycle device includes a compressor, a heater, an inside evaporator, an outside evaporator, a first refrigerant passage, a first decompressor, a second refrigerant passage, a second decompressor, an evaporating pressure adjusting valve, a third refrigerant passage, an opening-closing member, a charging port, and a pressure change buffer. The compressor compresses and discharges a refrigerant. The heater heats a heat-exchange target fluid using the refrigerant, as a heat source, discharged from the compressor. The outside evaporator exchanges heat between an outside air and the refrigerant flowing out of the heater. The inside evaporator exchanges heat between the refrigerant flowing out of the outside evaporator and the heat-exchange target fluid. The refrigerant flowing out of the heater is guided toward an inlet of the outside evaporator through the first refrigerant passage. The first decompressor is disposed in the first refrigerant passage and configured to vary an opening area of the first refrigerant passage. The refrigerant flowing out of the outside evaporator flows through the inside evaporator toward a suction inlet of the compressor through the second refrigerant passage. The second decompressor is disposed in the second refrigerant passage between the outside evaporator and the inside evaporator and configured to vary an opening area of the second refrigerant passage. The evaporating pressure adjusting valve is disposed in the second refrigerant passage at a position downstream of the inside evaporator and configured to adjust an evaporating pressure of the refrigerant in the inside evaporator. The third refrigerant passage has an end fluidly connected to a portion of the second refrigerant passage between the evaporating pressure adjusting valve and the compressor. The refrigerant flowing out of the outside evaporator is guided toward the suction inlet of the compressor through the third refrigerant passage. The charging port through which the refrigerant is supplied is disposed in the second refrigerant passage at a position downstream of the evaporating pressure adjusting valve. The pressure change buffer is disposed in the second refrigerant passage between the evaporating pressure adjusting valve and the charging port and defines a buffer space to restrict an inner pressure in the second refrigerant passage from rapidly changing when the refrigerant is supplied through the charging port
To begin with, examples of relevant techniques will be described.
A refrigeration cycle device includes a compressor, an outside evaporator, an inside evaporator, and an evaporating pressure adjusting valve. The evaporating pressure adjusting valve is configured to adjust an evaporating pressure of a refrigerant in the inside evaporator as a value equal to or higher than a frost restriction pressure to restrict a frost from generating on the inside evaporator. The evaporating pressure adjusting valve is configured to adjust an opening degree of the valve with a mechanical means.
The refrigeration cycle device includes a high-pressure charging port at a position downstream of the compressor to supply the refrigerant before shipping the cycle device. The refrigeration cycle device includes a low-pressure charging port at a downstream of a low-pressure evaporator to supply the refrigerant after shipping the cycle device.
The evaporating pressure adjusting valve of the refrigeration cycle device varies the opening degree of the valve according to a pressure difference between the refrigerant upstream of the valve and the refrigerant downstream of the valve. When the pressure of the refrigerant downstream of the valve exceeds the pressure of the refrigerant upstream of the valve and thus a counter pressure is applied to the evaporating pressure adjusting valve, a durability of the evaporating pressure adjusting valve may be impaired. Thus, the low-pressure charging port is typically disposed at a position upstream of the evaporating pressure adjusting valve.
As described above, it is difficult to arrange the low-pressure charging port at a position downstream of the evaporating pressure adjusting valve, and therefore a flexibility of positions at which the low-pressure charging port is disposed is limited. Thus, there has been demand for a refrigeration cycle device that can keep a durability of the evaporating pressure adjusting valve even though the low-pressure charging port is positioned downstream of the evaporating pressure adjusting valve.
It is objective of the present disclosure to provide a refrigeration cycle device that has a high flexibility in positioning of a charging port without impairing a durability of an evaporating pressure adjusting valve.
According to one aspect of the present disclosure, a refrigeration cycle device includes a compressor, a heater, an inside evaporator, an outside evaporator, a first refrigerant passage, a first decompressor, a second refrigerant passage, a second decompressor, an evaporating pressure adjusting valve, a third refrigerant passage, an opening-closing member, a charging port, and a pressure change buffer. The compressor compresses and discharges a refrigerant. The heater heats a heat-exchange target fluid using the refrigerant, as a heat source, discharged from the compressor. The outside evaporator exchanges heat between an outside air and the refrigerant flowing out of the heater. The inside evaporator exchanges heat between the refrigerant flowing out of the outside evaporator and the heat-exchange target fluid. The refrigerant flowing out of the heater is guided toward an inlet of the outside evaporator through the first refrigerant passage. The first decompressor is disposed in the first refrigerant passage and configured to vary an opening area of the first refrigerant passage. The refrigerant flowing out of the outside evaporator flows through the inside evaporator toward a suction inlet of the compressor through the second refrigerant passage. The second decompressor is disposed in the second refrigerant passage between the outside evaporator and the inside evaporator and configured to vary an opening area of the second refrigerant passage. The evaporating pressure adjusting valve is disposed in the second refrigerant passage at a position downstream of the inside evaporator and configured to adjust an evaporating pressure of the refrigerant in the inside evaporator. The third refrigerant passage has an end fluidly connected to a portion of the second refrigerant passage between the evaporating pressure adjusting valve and the compressor. The refrigerant flowing out of the outside evaporator is guided toward the suction inlet of the compressor through the third refrigerant passage. The charging port through which the refrigerant is supplied is disposed in the second refrigerant passage at a position downstream of the evaporating pressure adjusting valve. The pressure change buffer is disposed in the second refrigerant passage between the evaporating pressure adjusting valve and the charging port and defines a buffer space to restrict an inner pressure in the second refrigerant passage from rapidly changing when the refrigerant is supplied through the charging port
The pressure change buffer can restrict the inner pressure in the second refrigerant passage, in which the evaporating pressure adjusting valve is disposed, from rapidly changing when the refrigerant is supplied to the refrigeration cycle device through the charging port. Thus, a pressure change at an outlet side of the evaporating pressure adjusting valve can be suppressed. As a result, a durability of the evaporating pressure adjusting valve can be restricted from deteriorating even though the charging port is disposed at a position downstream of the evaporating pressure adjusting valve.
According to the present disclosure, it is possible to flexibly select a position for the charging port without impairing a durability of the evaporating pressure adjusting valve.
Hereinafter, embodiments for implementing the present disclosure will be described with reference to drawings. In the respective embodiments, parts corresponding to matters already described in the preceding embodiments are given reference numerals identical to reference numerals of the matters already described. The same description is therefore omitted depending on circumstances. When only a part of a configuration is described in an embodiment, another preceding embodiment may be applied to the other parts of the configuration. The present disclosure is not limited to combinations of embodiments which combine parts that are explicitly described as being combinable. As long as no problem is present, the various embodiments may be partially combined with each other even if not explicitly described.
First EmbodimentAn air conditioner 1 including a refrigeration cycle device 10 in a first embodiment will be described with reference to
The refrigeration cycle device 10 is configured to switch the refrigerant circuit between a heating mode, a cooling mode, a serial dehumidification heating mode, and a parallel dehumidification heating mode.
The heating mode of the air conditioner 1 is an operating mode in which a ventilation air is heated and conveyed to the vehicle cabin that is the air-conditioning target space. The serial dehumidification heating mode and the parallel dehumidification heating mode are operating modes in which the ventilation air having been cooled and dehumidified is heated and conveyed into the vehicle cabin that is the air-conditioning target space. The cooling mode is an operating mode in which the ventilation air is cooled and conveyed to the vehicle cabin that is the air-conditioning target space.
In
The refrigeration cycle device 10 uses a hydrofluorocarbon type refrigerant (i.e., HFC type refrigerant and specifically, R134a) as a refrigerant and constitutes a vapor compression type subcritical refrigerant cycle in which a pressure of a high pressure side refrigerant Pd does not exceed a critical pressure of the refrigerant. However, a hydrofluoroolefin type refrigerant (i.e., HFO type refrigerant) such as R1234yf may be used as the refrigerant. In addition, the refrigerant contains a refrigerant oil to lubricate a compressor 11 and a part of the refrigerant oil circulates through the cycle together with the refrigerant.
The refrigeration cycle device 10 includes the compressor 11, a condenser 12, a first decompression valve 15a (a first decompressor), a second decompression valve 15b (a second decompressor), an outside evaporator 16, a non-return valve 17, an inside evaporator 18, an evaporating pressure adjusting valve 19, an accumulator 20 (a pressure change buffer), a first opening-closing valve 21 (an opening-closing member), a second opening-closing valve 22, a low-pressure charging port 23, and a high-pressure charging port 24.
The compressor 11 sucks, compresses, and discharges the refrigerant in the refrigeration cycle device 10. The compressor 11 is disposed in an engine compartment of the vehicle. The compressor 11 is configured as an electric compressor in which a fixed-displacement type compression mechanism is driven by an electric motor. The fixed-displacement type compression mechanism has a fixed discharging capacity and may apply various types of compression mechanisms such as a scroll type compression mechanism and a vane type compression mechanism.
The operation of the electric motor such as a rotational speed is controlled by control signals outputted from an air conditioning controller. The electric motor may be an alternate current motor or direct current motor. The air conditioning controller controls the rotational speed of the electric motor to alter a refrigerant discharging capacity of the compression mechanism.
A discharge outlet of the compressor 11 is fluidly connected to a refrigerant inlet of the condenser 12. The condenser 12 is a heat exchanger for heating a cooling water through heat exchange between the high-temperature and high-pressure refrigerant discharged from the compressor 11 and the cooling water flowing through the heater 25 that is a heat-exchange target fluid. The high-pressure refrigerant is condensed when a heat of the high-pressure refrigerant is released to the cooling water.
The heater 25 includes the condenser 12, a cooling water circulating circuit 26, a heater core 27, and a cooling water pump 28. The heater 25 heats the ventilation air that is a heat-exchange target fluid using the high-pressure refrigerant, as a heat source, discharged from the compressor 11.
The cooling water flowing through the cooling water circulating circuit 26 may be a liquid including at least ethylene glycol, dimethylpolysiloxane, or nano-fluid, or the cooling water may be an antifreeze.
The cooling water circulating circuit 26 is an annular passage through which the cooling water circulates between the condenser 12 and the heater core 27. The condenser 12, the heater core 27, and the cooling water pump 28 are arranged in this order in the cooling water circulating circuit 26.
The cooling water pump 28 circulates the cooling water through the cooling water circulating circuit 26 by drawing and discharging the cooling water toward the condenser 12. The cooling water pump 28 is an electric pump and corresponds to a flow adjuster for the cooling water that adjusts a flow rate of the cooling water circulating through the cooling water circulating circuit 26.
The heater core 27 is disposed in a casing 31, as will be described later. The heater core 27 heats the ventilation air through heat exchange between the cooling water heated at the condenser 12 and the ventilation air that is a heat-exchange target fluid. The condenser 12 heats the ventilation air through the heater core 27.
A refrigerant outlet of the condenser 12 is fluidly connected to one of three openings of a first three-way joint 13a. Such three-way joint may be formed by joining multiple pipes or by defining multiple refrigerant passages at a metal block or a resin block. The refrigeration cycle device 10 further includes second to fourth three-way joints 13b to 13d as described later. Basic structures of the second to fourth three-way joints 13b to 13d are similar to that of the first three-way joint 13a.
Each of these three-way joints serves as a branching portion or joining portion. For example, the first three-way joint 13a in the parallel dehumidification heating mode uses one of the three openings as an inlet and the other two of the three openings as outlets. Accordingly, the first three-way joint 13a in the parallel dehumidification heating mode serves as a branching portion that divides a flow of the refrigerant flowing from the one inlet into two flows toward the two outlets.
The fourth three-way joint 13d in the parallel dehumidification heating mode uses two of the three openings as inlets and the other one of the three openings as an outlet. Accordingly, the fourth three-way joint 13d in the parallel dehumidification heating mode serves as a joining portion that joins refrigerants flowing into the fourth three-way joint 13d through the two inlets and discharges the joined refrigerant through the one outlet.
Another opening of the three openings of the first three-way joint 13a is fluidly connected to a first refrigerant passage 14a. The refrigerant flowing out of the condenser 12 is guided toward a refrigerant inlet of the outside evaporator 16 through the first refrigerant passage 14a. The other opening of the three openings of the first three-way joint 13a is fluidly connected to a fourth refrigerant passage 14d, and the refrigerant flowing out of the condenser 12 is guided toward an inlet of the second decompression valve 15b (specifically, one of openings of the third three-way joint 13c) through the fourth refrigerant passage 14d. The second decompression valve 15b is disposed in a second refrigerant passage 14b as described later.
The first decompression valve 15a is disposed in the first refrigerant passage 14a. The first decompression valve 15a can vary an opening area of the first refrigerant passage 14a and corresponds to the first decompressor that decompresses the refrigerant flowing out of the condenser 12 at least in the heating mode. The first decompression valve 15a is a variable throttle mechanism including a valve body configured to vary a throttle degree and an electric actuator including a stepper motor configured to control the throttle degree of the valve body.
The first decompression valve 15a is configured as a variable throttle mechanism with a full opening function in which the first decompression valve 15a serves as a refrigerant passage without decompressing the refrigerant by fully opening the valve body. An operation of the first decompression valve 15a is controlled by control signals (control pulse) outputted from the air conditioning controller.
An outlet of the first decompression valve 15a is fluidly connected to the refrigerant inlet of the outside evaporator 16. The outside evaporator 16 exchanges heat between the refrigerant flowing out of the first decompression valve 15a (i.e., out of the condenser 12) and an outside air blown by a blowing fan (not shown). The outside evaporator 16 is disposed at a vehicle front side of the engine compartment. The blowing fan is an electric blower whose rotational speed (i.e., a blower performance) is controlled by a control voltage outputted from the air conditioning controller.
A refrigerant outlet of the outside evaporator 16 is fluidly connected to the second refrigerant passage 14b. The second refrigerant passage 14b is a passage through which the refrigerant flowing out of the outside evaporator 16 flows through the inside evaporator 18 and is guided toward a suction inlet of the compressor 11. The second three-way joint 13b, the non-return valve 17, the third three-way joint 13c, the second decompression valve 15b, the inside evaporator 18, the evaporating pressure adjusting valve 19, the fourth three-way joint 13d, the accumulator 20, and the low-pressure charging port 23 are disposed in the second refrigerant passage 14b in this order along a flow direction of the refrigerant. An end of the second refrigerant passage 14b is fluidly connected to the suction inlet of the compressor 11.
An opening of the second three-way joint 13b is fluidly connected to the third refrigerant passage 14c through which the refrigerant flowing out of the outside evaporator 16 is guided toward an inlet of the accumulator 20, as will be described later (specifically, the refrigerant is guided to one of the openings of the fourth three-way joint 13d). The third three-way joint 13c is fluidly connected to the fourth refrigerant passage 14d as described above.
The non-return valve 17 allows the refrigerant to flow only from the second three-way joint 13b (i.e., from the outside evaporator 16) toward the inside evaporator 18.
The second decompression valve 15b is disposed in the second refrigerant passage 14b between the outside evaporator 16 and the inside evaporator 18. In this embodiment, the second decompression valve 15b is disposed in the second refrigerant passage 14b between the third three-way joint 13c and the inside evaporator 18. The second decompression valve 15b is configured to vary an opening area of the second refrigerant passage 14b and corresponds to the second decompressor that decompresses the refrigerant flowing out of the outside evaporator 16 into the inside evaporator 18. A basic structure of the second decompression valve 15b is the same as that of the first decompression valve 15a. Additionally, the second decompression valve 15b in this embodiment is configured as a variable throttle mechanism with a full-closing function in which the second refrigerant passage 14b is completely closed when a throttle of the valve is fully closed.
Accordingly, the refrigeration cycle device 10 in this embodiment can switch the refrigeration circuit by controlling the second decompression valve 15b to close the second refrigerant passage 14b. In other words, the second decompression valve 15b serves not only as a refrigerant decompressor but also as a refrigerant circuit switching device to switch a refrigerant circuit of the refrigerant circulating through the cycle.
In the cooling, the serial dehumidification heating, and the parallel dehumidification heating modes, the inside evaporator 18 serves as a heat exchanger for cooling that exchanges heat between the refrigerant flowing out of the second decompression valve 15b (i.e., out of the outside evaporator 16) and the ventilation air (i.e., a heat-exchange target fluid) before passing through the heater core 27. The inside evaporator 18 cools the ventilation air by an endothermic action of evaporating the refrigerant decompressed by the second decompression valve 15b. The inside evaporator 18 is disposed at a position upstream of the heater core 27 in a flow direction of the ventilation air in the casing 31 of the inside air-conditioning unit 30.
The refrigerant passage 14b is fluidly connected, at a position downstream of the inside evaporator 18 in the flow direction of the refrigerant, to an inlet of the evaporating pressure adjusting valve 19. The evaporating pressure adjusting valve 19 adjusts an evaporating pressure Pe of the refrigerant in the inside evaporator 18 to be equal to or greater than a frost restricting pressure Ape so as to restrict a frost from generating on the inside evaporator 18. In other words, the evaporating pressure adjusting valve 19 adjusts an evaporating temperature Te of the refrigerant in the inside evaporator 18 to be equal to or greater than a frost restricting temperature Ate.
In this embodiment, R134a is used as a refrigerant and the frost restricting temperature Ate is set to have a value slightly higher than 0° C. Accordingly, the frost restricting pressure APe is set to have a value slightly higher than 0.293 MPa that is a saturated pressure of R134a at 0° C.
The second refrigerant passage 14b at a position downstream of the evaporating pressure adjusting valve 19 is fluidly connected to the fourth three-way joint 13d. The fourth three-way joint 13d is fluidly connected to the third refrigerant passage 14c as described above. That is, the third refrigerant passage 14c has an end connected to the fourth three-way joint 13d that is a joining portion disposed in the second refrigerant passage 14b between the evaporating pressure adjusting valve 19 and the compressor 11.
The other opening of the fourth three-way joint 13d is fluidly connected to an inlet of the accumulator 20. That is, the accumulator 20 is disposed in the second refrigerant passage 14b between the evaporating pressure adjusting valve 19 and the low-pressure charging port 23. In this embodiment, the accumulator 20 is disposed at a position downstream of the fourth three-way joint 13d that is the joining portion of the third refrigerant passage 14c and the second refrigerant passage 14b.
The accumulator 20 defines a buffer space 20a therein. The accumulator 20 is a gas-liquid separator that separates the refrigerant flowing therein into a gas-phase and a liquid-phase and reserves an excess amount of the refrigerant in the cycle in the buffer space 20a. The buffer space 20a of the accumulator 20 serves as a reservoir to reserve the excess amount of the refrigerant in the cycle.
The buffer space 20a of the accumulator 20 increases the capacity of a passage between the low-pressure charging port 23 and the evaporating pressure adjusting valve 19 as compared when the buffer space 20a is not formed. Thus, the buffer space 20a of the accumulator 20 serves as a pressure change buffer to restrict an inner pressure in the second refrigerant passage 14b from rapidly changing when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23.
The accumulator 20 has a gas-phase refrigerant outlet fluidly connected to the suction inlet of the compressor 11. Accordingly, the accumulator 20 restricts the compressor 11 from sucking the liquid-phase refrigerant and prevents a liquid compression in the compressor 11.
The first opening-closing valve 21 is disposed in the third refrigerant passage 14c that fluidly connects the second three-way joint 13b and the fourth three-way joint 13d. The first opening-closing valve 21 is an electromagnetic valve as a refrigerant circuit switching device that switches a refrigerant circuit, through which the refrigerant circulates, by selectively opening and closing the third refrigerant passage 14c. The first opening-closing valve 21 is an opening-closing member whose operation is controlled by control signals outputted from the air conditioning controller.
The second opening-closing valve 22 is disposed in the fourth refrigerant passage 14d that fluidly connects the first three-way joint 13a and the third three-way joint 13c. The second opening-closing valve 22 is an electromagnetic valve as a refrigerant circuit switching device that switches a refrigerant circuit, through which the refrigerant circulates, by selectively opening and closing the fourth refrigerant passage 14d. A basic structure of the second opening-closing valve 22 is the same as that of the first opening-closing valve 21.
The low-pressure charging port 23 is located in the second refrigerant passage 14b at a position downstream of the evaporating pressure adjusting valve 19. In this embodiment, the low-pressure charging port 23 is located in the second refrigerant passage 14b between the accumulator 20 and the compressor 11. The low-pressure charging port 23 is used to supply the refrigerant into the refrigeration cycle device 10 while operating the compressor 11 after the vehicle (i.e., the refrigeration cycle device 10) is shipped.
The high-pressure charging port 24 is located in the first refrigerant passage 14a at a position downstream of the condenser 12. In this embodiment, the high-pressure charging port 24 is located in the first refrigerant passage 14a between the first three-way joint 13a and the first decompression valve 15a. The high-pressure charging port 24 is used to supply the refrigerant into the refrigerant cycle device 10 before the vehicle (i.e., the refrigeration cycle device 10) is shipped.
Next, the inside air-conditioning unit 30 will be described. The inside air-conditioning unit 30 conveys the ventilation air temperature-adjusted by the refrigeration cycle device 10 into the vehicle cabin that is an air-conditioning target space. The inside air-conditioning unit 30 is disposed in an instrument panel that defines the most front side of the vehicle cabin. The inside air conditioning unit 30 includes a blower 32, the inside evaporator 18, and the heater core 27 in the casing 31 constituting an outer frame thereof.
The casing 31 is an air passage forming portion that defines a passage of the ventilation air conveyed to the vehicle cabin that is an air-conditioning target space. The casing 31 is made of resin such as polypropylene having a certain degree of an elasticity and great strength. An inside outside air switching device 33 is located at the most upstream side in the casing in the flow of the ventilation air. The inside outside air switching device 33, as an inside outside switching portion, switches air introduced into the casing between an inside air (i.e., air inside the air-conditioning target space) and an outside air (i.e., air outside the air-conditioning target space).
The blower 32 is located at a position downstream of the inside outside air switching device 33 in the flow direction of the ventilation air. The blower 32 blows an air drawn through the inside outside air switching device 33 toward the air-conditioning target space. The blower 32 is an electric blower that drives a centrifugal multi blades fan (i.e., sirocco fan) by an electric motor. The rotational speed (i.e., a flow rate) of the blower 32 is controlled by a control voltage outputted from the air conditioning controller.
The inside evaporator 18 is disposed in the air passage defined by the casing 31 at a position downstream of the blower 32 in the flow direction of the ventilation air. A space downstream of the inside evaporator 18 in the air passage defined by the casing 31 is divided into two spaces so that an inside condenser passage 35 and a cooling air bypass passage 36 are formed in parallel with each other.
The heater core 27 is disposed in the inside condenser passage 35. That is, the inside condenser passage 35 is a passage through which the ventilation air flows to exchange its heat with the refrigerant at the heater core 27. The inside evaporator 18 and the heater core 27 are arranged in this order in the flow direction of the ventilation air. In other words, the inside evaporator 18 is located upstream of the heater core 27 in the flow direction of the ventilation air.
The cooling air bypass passage 36 is a passage through which the ventilation air that has passed through the inside evaporator 18 flows while bypassing the heater core 27.
An air mix door 34 is disposed at a position downstream of the inside evaporator 18 and upstream of the heater core 27 in the flow direction of the ventilation air. The air mix door 34 is a flow ratio adjuster that adjusts an amount of the ventilation air passing through the heater core 27 that has passed through the inside evaporator 18 based on control signals outputted from the air conditioning controller.
A mixing passage 37 is defined in the casing 31 at a position downstream of the inside condenser passage 35 and the cooling air bypass passage 36. The ventilation air heated at the heater core 27 is mixed with the ventilation air flowing through the cooling air bypass passage 36 without being heated at the heater core 27 in the mixing passage 37.
Multiple openings are defined at the most downstream side of the casing 31 in the flow direction of the ventilation air. The ventilation air (i.e., conditioned air) mixed at the mixing passage 37 is conveyed toward the vehicle cabin through the multiple openings.
The air mix door 34 adjusts the ratio of an amount of air passing through the heater core 27 and an amount of air flowing through the cooling air bypass passage 36, and therefore a temperature of the conditioned air mixed in the mixing passage 37 is adjusted. As a result, a temperature of the conditioned air conveyed into the vehicle cabin that is an air-conditioning target space is adjusted.
That is, the air mix door 34 serves as a temperature adjuster that adjusts a temperature of the conditioned air blown into the vehicle cabin that is an air-conditioning target space. The air mix door 34 is driven by an electric actuator for the air mix door 34. The operation of the electric actuator is controlled by control signals outputted from the air conditioning controller.
The air mix door 34 causes the ventilation air to flow through the inside evaporator 18 and the heater core 27 in this order during the heating mode, the serial dehumidification heating mode, and the parallel dehumidification heating mode. The air mix door 34 causes the ventilation air to flow through the inside evaporator 18 and bypass the heater core 27 during the cooling mode. The air mix door 34 serves as an air passage switching device.
Next, an operation of the air conditioner 1 in this embodiment will be described. The air conditioner 1 in this embodiment can switch the operating mode between the heating mode, the cooling mode, the serial dehumidification heating mode, and the parallel dehumidification heating mode. These operating modes are selectively switched by executing air-conditioning control programs stored in the air conditioning controller in advance.
(a) Heating ModeIn the heating mode, the air conditioning controller opens the first opening-closing valve 21, closes the second opening-closing valve 22, controls the first decompression valve 15a to serve as a decompressor by reducing a throttle of the first decompression valve 15a, and fully closes the second decompression valve 15b.
In the heating mode, as shown by the black arrows in
In this cycle, the air conditioning controller appropriately controls operations of air conditioning devices connected to an output portion of the air conditioning controller. The air conditioning controller determines control signals outputted to the electric actuator for the air mix door 34 such that the air mix door 34 completely closes the cooling air bypass passage 36. That is, the control signals are determined such that all of the ventilation air that has passed through the inside evaporator 18 flows through the air passage in which the heater core 27 is disposed.
Accordingly, in the refrigeration cycle device 10 in the heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The refrigerant flowing through the condenser 12 exchanges heat with the cooling water flowing through the cooling water circulating circuit 26 and releases the heat. As a result, the cooling water flowing through the cooling water circulating circuit 26 is heated. The ventilation air that has been blown by the blower 32 and passed through the inside evaporator 18 is heated at the heater core 27 because the air mix door 34 opens the air passage in which the heater core 27 is disposed.
The refrigerant flowing out of the condenser 12 flows through the first three-way joint 13a toward the first refrigerant passage 14a because the second opening-closing valve 22 is closed. The refrigerant flowing through the first refrigerant passage 14a is decompressed to be a low-pressure refrigerant by the first decompression valve 15a. The low-pressure refrigerant decompressed by the first decompression valve 15a flows into the outside evaporator 16 and absorbs heat from an outside air blown by the blowing fan.
The refrigerant flowing out of the outside evaporator 16 flows through the second three-way joint 13b toward the third refrigerant passage 14c because the first opening-closing valve 21 is opened and the second decompression valve 15b is completely closed. The refrigerant flowing through the third refrigerant passage 14c flows through the fourth three-way joint 13d into the accumulator 20 and is separated into a gas-phase and a liquid-phase. The gas-phase refrigerant separated in the accumulator 20 is sucked by the compressor 11 through the suction inlet and compressed again by the compressor 11.
Accordingly, in the heating mode, the ventilation air heated at the heater core 27 through the condenser 12 is blown into the vehicle cabin that is an air-conditioning target space to perform an air-heating in the vehicle cabin.
(b) Cooling ModeIn the cooling mode, the air conditioning controller closes the first opening-closing valve 21 and the second opening-closing valve 22, fully opens the first decompression valve 15a, and reduces the throttle of the second decompression valve 15b.
In the cooling mode, as shown by white arrows in
In this cycle, the air conditioning controller appropriately controls the air conditioning devices connected to the output portion of the air conditioning controller. The control signals outputted to the electric actuator for the air mix door 34 from the air conditioning controller are set such that the air mix door 34 fully opens the cooling air bypass passage 36. Thus, all amount of the ventilation air that has passed through the inside evaporator 18 flows through the cooling air bypass passage 36.
Accordingly, in the refrigeration cycle device 10 in the cooling mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. At this time, the air mix door 34 completely closes the air passage in which the heater core 27 is disposed, thus the cooling water flowing through the heater core 27 rarely exchanges heat with the ventilation air and flows out of the heater core 27.
The refrigerant flowing out of the condenser 12 flows through the first three-way joint 13a toward the first refrigerant passage 14a because the second opening-closing valve 22 is closed. The refrigerant flowing through the first refrigerant passage 14a flows into the first decompression valve 15a. At this moment, the refrigerant flowing out of the condenser 12 is not decompressed by the first decompression valve 15a and flows into the outside evaporator 16 because the first decompression valve 15a is fully opened.
The refrigerant flowing through the outside evaporator 16 releases heat to the outside air blown by the blowing fan at the outside evaporator 16. The refrigerant flowing out of the outside evaporator 16 flows through the second three-way valve 13b toward the second refrigerant passage 14b because the first opening-closing valve 21 is closed. The refrigerant flowing through the second refrigerant passage 14b is decompressed to be a low-pressure refrigerant by the second decompression valve 15b.
The low-pressure refrigerant decompressed by the second decompression valve 15b flows into the inside evaporator 18 and evaporates by absorbing heat from the ventilation air blown by the blower 32. Thus, the ventilation air is cooled. The refrigerant flowing out of the inside evaporator 18 flows through the evaporating pressure adjusting valve 19 into the accumulator 20 and is separated into a gas-phase and a liquid-phase in the accumulator 20. The gas-phase refrigerant separated at the accumulator 20 is sucked by the compressor 11 through the suction inlet and compressed by the compressor 11 again.
Accordingly, in the cooling mode, the ventilation air cooled at the inside evaporator 18 is blown into the vehicle cabin that is an air-conditioning target space, thereby performing an air-cooling in the vehicle cabin.
(c) Serial Dehumidification Heating ModeIn the serial dehumidification heating mode, the air conditioning controller closes the first opening-closing valve 21 and the second opening-closing valve 22 and reduces throttles of the first decompression valve 15a and the second decompression valve 15b. The air conditioning controller displaces the air mix door 34 such that the air passage in which the heater core 27 is disposed is fully opened and the cooling air bypass passage 36 is fully closed.
The refrigeration cycle device 10 in the serial dehumidification heating mode constitutes a vapor compression type refrigeration cycle, as shown by white arrows in
The refrigeration cycle device 10 in the serial dehumidification heating mode constitutes a refrigeration cycle in which the condenser 12 serves as a radiator and the inside evaporator 18 serves as an evaporator. When a saturated temperature of the refrigerant in the outside evaporator 16 is higher than an outside temperature Tam, the outside evaporator 16 serves as a radiator. When the saturated temperature of the refrigerant in the outside evaporator 16 is lower than the outside temperature Tam, the outside evaporator 16 serves as an evaporator.
In this cycle, the air conditioning controller appropriately controls operations of the air conditioning devices connected to the output portion of the air conditioning controller. The control signals outputted to the electric actuator for the air mix door 34 from the air conditioning controller are set such that the air mix door 34 completely closes the cooling air bypass passage 36 as with in the heating mode. That is, the control signals are determined such that all amount of the air having passed through the inside evaporator 18 flows through the air passage in which the heater core 27 is disposed.
Accordingly, in the serial dehumidification heating mode, the ventilation air cooled and dehumidified at the inside evaporator 18 is heated at the heater core 27 and blown into the vehicle cabin that is an air-conditioning target space. Thus, air in the vehicle cabin is dehumidified and heated. Additionally, a heating capacity of the heater core 27 for the ventilation air can be adjusted by adjusting the throttle degrees of the first decompression valve 15a and the second decompression valve 15b.
(d) Parallel Dehumidification Heating ModeIn the parallel dehumidification heating mode, the air conditioning controller opens the first opening-closing valve 21 and the second opening-closing valve 22 and reduces the throttles of the first decompression valve 15a and the second decompression valve 15b.
As shown by arrows with diagonal hatching in
That is, in the parallel dehumidification heating mode, the flow of the refrigerant flowing out of the condenser 12 is separated into two flows at the first three-way joint 13a. One of the two flows of the refrigerant flows through the first decompression valve 15a, the outside evaporator 16, and the compressor 11 in this order, and the other one of the two flows of the refrigerant flows through the second decompression valve 15b, the inside evaporator 18, the evaporating pressure adjusting valve 19, and the compressor in this order.
In this cycle, the air conditioning controller appropriately controls operations of the air conditioning devices connected to the output portion of the air conditioning controller. For example, the control signals outputted to the electric actuator for the air mix door 34 from the air conditioning controller are set such that the air mix door 34 fully closes the cooling air bypass passage 36 as with in the heating mode. That is, the control signals are determined such that the all amount of the ventilation air having passed through the inside evaporator 18 flows through the air passage in which the heater core 27 is disposed.
Accordingly, in the refrigeration cycle device 10 in the parallel dehumidification heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The refrigerant flowing in the condenser 12 exchanges heat with and releases heat to the cooling water. The ventilation air that has been blown by the blower 32 and passed through the inside evaporator 18 is heated by the cooling water heated by the refregerant similarly to the heating mode because the air mix door 34 opens the air passage in which the heater core 27 is disposed. As a result, the ventilation air is heated.
The second opening-closing valve 22 is opened, thus the flow of the refrigerant flowing out of the condenser 12 is separated into the two flows at the first three-way joint 13a. One of the two flows of the refrigerant separated at the first three-way joint 13a flows through the first refrigerant passage 14a. The refrigerant flowing through the first refrigerant passage 14a is decompressed to be a low-pressure refrigerant at the first decompression valve 15a. The low-pressure refrigerant decompressed by the first decompression valve 15a flows into the outside evaporator 16 and absorbs heat from an outside air blown by the blowing fan.
The other one of the two flows of the refrigerant separated at the first three-way joint 13a flows through the fourth refrigerant passage 14d. The refrigerant flowing through the fourth refrigerant passage 14d is restricted from flowing back toward the outside evaporator 16 by the non-return valve 17 and flows through the second opening-closing valve 22 and the third three-way joint 13c into the second decompression valve 15b.
The refrigerant flowing through the second decompression valve 15b is decompressed to be a low-pressure refrigerant. The low-pressure refrigerant decompressed by the second decompression valve 15b flows into the inside evaporator 18 and evaporates by absorbing heat from the ventilation air blown by the blower 32. As a result, the ventilation air is cooled. The refrigerant flowing out of the inside evaporator 18 is decompressed by the evaporating pressure adjusting valve 19 to have a value substantially equal to the pressure of the refrigerant flowing out of the outside evaporator 16.
The refrigerant flowing out of the evaporating pressure adjusting valve 19 flows through the fourth three-way joint 13d and merges with the refrigerant flowing out of the outside evaporator 16. The refrigerant merging at the fourth three-way joint 13d flows into the accumulator 20 and is separated into a gas-phase and a liquid-phase. The gas-phase refrigerant separated at the accumulator 20 is sucked by the compressor 11 through the suction inlet and compressed again by the compressor 11.
In the parallel dehumidification heating mode, the ventilation air cooled and dehumidified at the inside evaporator 18 is heated at the heater core 27 and blown into the vehicle cabin that is an air-conditioning target space. As a result, air in the vehicle cabin is dehumidified and heated.
In addition, in the parallel dehumidification heating mode in this embodiment, the evaporating temperature of the refrigerant in the outside evaporator 16 can be lowered than the evaporating temperature in the inside evaporator 18. Accordingly, a temperature difference between the evaporating temperature of the refrigerant in the outside evaporator 16 and the outside air can be increased, thereby increasing an amount of air absorbed by the refrigerant at the outside evaporator 16.
As a result, the heating capacity of the heater core 27 for the ventilation air can be increased compared to a refrigeration cycle device in which the evaporating temperature of the refrigerant in the outside evaporator 16 is similar to the evaporating temperature of the refrigerant in the inside evaporator 18.
As described above, the refrigeration cycle device 10 in this embodiment can perform a comfortable air-heating in the vehicle cabin by selectively switching the operating mode between the heating mode, the cooling mode, the serial dehumidification heating mode, and the parallel dehumidification heating mode.
Next, a method to supply the refrigerant into the refrigeration cycle device 10 will be described. Before the air conditioner 1 (i.e., the refrigeration cycle device 10) is shipped out, the first decompression valve 15a and the second decompression valve 15b are fully opened. The refrigeration cycle device 10 is vacuumed through the high-pressure charging port 24 and the low-pressure charging port 23 while opening the first opening-closing valve 21 and the second opening-closing valve 22.
The refrigeration cycle device 10 is vacuumed to remove air in the refrigeration cycle device 10. If air is remained in the refrigeration cycle device 10, water vapor in the air would freeze in the refrigeration cycle device 10, which prevents the refrigerant from circulating through the refrigeration cycle device 10.
After the refrigeration cycle device 10 is vacuumed, the first decompression valve 15a and the second decompression valve 15b are fully opened. The refrigerant is supplied into the refrigeration cycle device 10 through the high-pressure charging port 24 while opening the first opening-closing valve 21 and the second opening-closing valve 22.
After shipping out the air conditioner 1 (i.e., the refrigeration cycle device 10), the first decompression valve 15a and the second decompression valve 15b are fully opened. The refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23 while opening the first opening-closing valve 21 and the second opening-closing valve 22 and operating the compressor 11.
As described above, the accumulator 20 is disposed in the second refrigerant passage 14b between the evaporating pressure adjusting valve 19 and the low-pressure charging port 23. The accumulator 20, which is a pressure change buffer, restricts an inner pressure in the second refrigerant passage 14b from rapidly changing when the refrigerant is supplied through the low-pressure charging port 23.
The accumulator 20 defines the buffer space 20a, thereby restricting the inner pressure in the second refrigerant passage 14b from rapidly changing when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23 and the second refrigerant passage 14b. The reason why the rapid change in the inner pressure is avoided is that the air in the buffer space 20a is compressed. Thus, it is possible to suppress a pressure change at an outlet side of the evaporating pressure adjusting valve 19. In addition, even though the low-pressure charging port 23 is disposed at a position downstream of the evaporating pressure adjusting valve 19, a durability of the evaporating pressure adjusting valve 19 is restricted from being impaired.
The refrigeration cycle device 10 in this embodiment can improve a flexibility of positions at which the charging port is mounted without impairing the durability of the evaporating pressure adjusting valve.
The buffer space 20a is defined by the accumulator 20 that is a reservoir to reserve an excess amount of the refrigerant. The buffer space 20a of the accumulator 20 that has been already installed as a reservoir in the refrigeration cycle device 10 is used as a pressure change buffer, thus an additional pressure change buffer is not needed. Therefore, a cost and a size of the refrigeration cycle device 10 are not increased. The refrigeration cycle device 10 that keeps the durability of the evaporating pressure adjusting valve 19 can be provided even though the low-pressure charging port 23 is located at a position downstream of the evaporating pressure adjusting valve 19.
Second EmbodimentHereinafter, a refrigeration cycle device 10 in a second embodiment will be described with reference to
The muffler 51 defines a buffer space 51a that reduces a pressure pulsation generated when the compressor 11 discharges the refrigerant. The buffer space 51a also serves as a pressure change buffer that restricts the inner pressure in the second refrigerant passage 14b from changing when the refrigerant is supplied into the second refrigerant passage 14b through the low-pressure charging port 23.
The buffer space 51a of the muffler 51 increases the capacity of a passage through which the refrigerant flows between the evaporating pressure adjusting valve 19 and the low-pressure charging port 23. Thus, air in the buffer space 51a is compressed when the refrigerant is supplied into the second refrigerant passage 14b through the low-pressure charging port 23, thereby further restricting the inner pressure in the second refrigerant passage 14b from rapidly increasing. Thus, the pressure of the second refrigerant passage 14b at a position downstream of the evaporating pressure adjusting valve 19 is further restricted from changing.
As described above, the buffer space 51a is configured with the muffler 51 that reduces the pressure pulsation generated when the compressor 11 discharges the refrigerant. The refrigeration cycle device 10 including the muffler 51 does not need an additional member as a pressure change buffer. Thus, the refrigeration cycle device 10 can keep the durability of the evaporating pressure adjusting valve 19 without increasing a cost and a size of the refrigeration cycle device 10 even though the low-pressure charging port 23 is disposed at a position downstream of the evaporating pressure adjusting valve 19. The pressure in the second refrigerant passage 14b at a position downstream of the evaporating pressure adjusting valve 19 is further restricted from changing when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23.
Third EmbodimentA refrigeration cycle device 10 in a third embodiment will be described with reference to
The buffer space 52 is defined by repeatedly bending a pipe. The buffer space 52 increases a length of a passage through which the refrigerant flows between the evaporating pressure adjusting valve 19 and the low-pressure charging port 23 and increases the capacity of the passage through which the refrigerant flows.
The buffer space 52 may be defined by branching multiple pipes and joining these multiple pipes to increase the capacity of the passage through which the refrigerant flows.
The buffer space 52 increases the capacity of the passage through which the refrigerant flows between the evaporating pressure adjusting valve 19 and the low-pressure charging port 23. When the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23 and the second refrigerant passage 14b, air in the buffer space 52 is compressed. Thus, the inner pressure in the second refrigerant passage 14b is further restricted from rapidly changing. As a result, a pressure in the second refrigerant passage 14b downstream of the evaporating pressure adjusting valve 19 is further restricted from changing.
As described above, the buffer space 52 is defined by the pipe. Accordingly, a structure to restrict a pressure at the outlet side of the evaporating pressure adjusting valve 19 from changing can be achieved at a low cost.
The present disclosure is not limited to the embodiments described above, and can be variously modified in a range without departing from a gist of the present disclosure.
In the above embodiments, the refrigeration cycle device 10 in the present disclosure is applied to the vehicle, but the refrigeration cycle device 10 is not limited to a device for a vehicle and may be applied to a stationary refrigeration cycle device.
Components of the refrigeration cycle device 10 are not limited to those described in the embodiments. In the embodiments, the compressor 11 is an electric compressor, but not limited to this. When the compressor 11 is used for an engine for vehicle driving, the compressor 11 may be an engine driven compressor that is driven by a rotational driving force transmitted by the engine through a pulley and a belt.
Means disclosed in the above embodiments can be combined with each other in a practical range. For example, the air conditioner may be configured by combining the refrigeration cycle device 10 in the second embodiment and the refrigeration cycle device 10 in the third embodiment.
The low-pressure charging port 23 may include a throttle such as an orifice to further restrict a pressure at a position downstream of the evaporating pressure adjusting valve 19 from changing when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23.
A method to supply the refrigerant into the refrigeration cycle device 10 after the air conditioner 1 (i.e., the refrigeration cycle device 10) is shipped out is not limited to the method described above. Hereinafter, another method will be described.
At first, a predetermined amount of the refrigerant is supplied into the refrigeration cycle device 10 through the high-pressure charging port 24 while fully opening the first decompression valve 15a and the second decompression valve 15b and opening the first opening-closing valve 21 and the second opening-closing valve 22.
Next, the refrigerant is further supplied into the refrigeration cycle device 10 through the low-pressure charging port 23 while completely closing the high-pressure charging port 24 and operating the compressor 11.
After the predetermined amount of the refrigerant is supplied into the refrigeration cycle device 10 through the high-pressure charging port 24 as described above, the refrigerant is further supplied through the low-pressure charging port 23.
In this case, when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23, the predetermined amount of the refrigerant has been already supplied into the refrigeration cycle device 10. Accordingly, a pressure difference between the refrigerant supplied into the refrigeration cycle device 10 through the low-pressure charging port 23 and the refrigerant in the refrigeration cycle device 10 can be decreased. Thus, a counter pressure is not likely to act on the evaporating pressure adjusting valve 19 while the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23.
Therefore, a pressure at the outlet side of the evaporating pressure adjusting valve 19 is further restricted from rapidly changing when the refrigerant is supplied into the refrigeration cycle device 10 through the low-pressure charging port 23.
The predetermined amount of the refrigerant supplied into the refrigeration cycle device 10 through the high-pressure charging port 24 is predetermined such that the pressure at a position downstream of the evaporating pressure adjusting valve 19 is restricted from rapidly changing when the refrigerant is supplied into the second refrigerant passage 14b through the low-pressure charging port 23.
Although the present disclosure has been described in accordance with the examples, it is understood that the disclosure is not limited to such examples or structures. The present disclosure encompasses various modifications and variations within the scope of equivalents. In addition, it should be understood that various combinations or aspects, or other combinations or aspects, in which only one element, one or more elements, or one or less elements are added to the various combinations or aspects, also fall within the scope or technical idea of the present disclosure.
Claims
1. A refrigeration cycle device comprising:
- a compressor configured to compress and discharge a refrigerant;
- a heater configured to heat a heat-exchange target fluid using the refrigerant, as a heat source, discharged from the compressor;
- an outside evaporator configured to exchange heat between an outside air and the refrigerant flowing out of the heater;
- an inside evaporator configured to exchange heat between the refrigerant flowing out of the outside evaporator and the heat-exchange target fluid;
- a first refrigerant passage through which the refrigerant flowing out of the heater is guided toward an inlet of the outside evaporator;
- a first decompressor disposed in the first refrigerant passage and configured to vary an opening area of the first refrigerant passage;
- a second refrigerant passage through which the refrigerant flowing out of the outside evaporator passes through the inside evaporator and is guided toward a suction inlet of the compressor;
- a second decompressor disposed in the second refrigerant passage between the outside evaporator and the inside evaporator and configured to vary an opening area of the second refrigerant passage;
- an evaporating pressure adjusting valve disposed in the second refrigerant passage at a position downstream of the inside evaporator and configured to adjust an evaporating pressure of the refrigerant in the inside evaporator;
- a third refrigerant passage having an end fluidly connected to a portion of the second refrigerant passage between the evaporating pressure adjusting valve and the compressor, the refrigerant flowing out of the outside evaporator being guided toward the suction inlet of the compressor through the third refrigerant passage;
- an opening-closing member configured to selectively open and close the third refrigerant passage;
- a charging port disposed in the second refrigerant passage at a position downstream of the evaporating pressure adjusting valve to supply the refrigerant therethrough; and
- a pressure change buffer disposed in the second refrigerant passage between the evaporating pressure adjusting valve and the charging port, the pressure change buffer defining a buffer space therein to restrict an inner pressure in the second refrigerant passage from rapidly changing when the refrigerant is supplied through the charging port.
2. The refrigeration cycle device according to claim 1, wherein
- the buffer space is defined by a reservoir that reserves an excess amount of the refrigerant.
3. The refrigeration cycle device according to claim 1, wherein
- the buffer space is defined by a muffler that is configured to reduce a pressure pulsation generated when the refrigerant is discharged from the compressor.
4. The refrigeration cycle device according to claim 1, wherein
- the buffer space is defined by a pipe.
Type: Application
Filed: Jun 3, 2020
Publication Date: Sep 17, 2020
Inventor: Yuji KAWAZOE (Kariya-city)
Application Number: 16/892,001
