HEAT EXCHANGER AND AIR-CONDITIONING APPARATUS INCLUDING THE SAME

Abstract

A heat exchanger includes: heat transfer tubes; a first header; a second header; and a gas separation pipe. The first header includes a partition wall that partitions an internal space of the first header into spaces including a main flow space and a gas separation space. The partition wall has first openings through which the main flow space and the gas separation space communicate with each other. The gas separation space is located above the main flow space. The gas separation space and the refrigerant pipe are connected by the gas separation pipe.

Description

TECHNICAL FIELD

The present disclosure relates to a heat exchanger including a plurality of heat transfer tubes and an air-conditioning apparatus including the heat exchanger.

BACKGROUND ART

At an existing heat exchanger that causes heat exchange to be performed between air and refrigerant, two-phase gas-liquid refrigerant is distributed to a plurality of heat transfer tubes connected to a header portion serving as a refrigerant distributor. Distribution characteristics regarding the flow rate of liquid refrigerant to each of the heat transfer tubes vary depending on the structure of the header portion and have an effect on the heat exchange performance. For example, in a configuration in which the header portion extends in the horizontal direction and the plurality of heat transfer tubes extend in the direction of gravitational force, when refrigerant flows in the header portion, the distribution characteristics of the refrigerant greatly vary depending on a quality that is the mass ratio of gas refrigerant to liquid refrigerant and the flow velocity of refrigerant that flows in the header portion.

At a refrigerant inlet of the header portion, in the case where the quality of the refrigerant is low, that is, the ratio of liquid refrigerant in the refrigerant is high, the distribution characteristics of the refrigerant is improved, and the heat exchange performance of the heat exchanger is improved. In a known heat exchanger, a gas-liquid separator is provided upstream of a header portion in the flow direction of refrigerant in order to reduce the quality of the refrigerant at a refrigerant inlet of the header portion (for example, see Patent Literature 1).

CITATION LIST

Patent Literature

• Patent Literature 1: Japanese Patent No. 3122578

SUMMARY OF INVENTION

Technical Problem

In a heat exchanger disclosed in Patent Literature 1, it is necessary to further provide a gas-liquid separator as a refrigerant assist device, in addition to a header portion.

The present disclosure is applied to solve the above problem, and relates to a heat exchanger that is improved in refrigerant distribution characteristics regarding distribution of refrigerant to a plurality of heat transfer tubes without further providing a refrigerant assist device, and to an air-conditioning apparatus including the heat exchanger.

Solution to Problem

A heat exchanger according to one embodiment of the present disclosure causes heat exchange to be performed between air and refrigerant, and includes: a plurality of heat transfer tubes that extend in a direction of gravitational force, the plurality of heat transfer tubes being arranged apart from each other in a horizontal direction orthogonal to the direction of gravitational force; a first header connected to the plurality of heat transfer tubes at end portions thereof in the opposite direction to the direction of gravitational force; a second header connected to the plurality of heat transfer tubes at end portions thereof in the direction of gravitational force; and a gas separation pipe connecting the first header and a refrigerant pipe through which the refrigerant flows out of the second header when the heat exchanger operates as an evaporator. The first header includes a partition wall that partitions an internal space of the first header into a plurality of spaces including a main flow space and a gas separation space. The partition wall has a plurality of first openings through which the main flow space and the gas separation space communicate with each other. The gas separation space is located above the main flow space. The gas separation space and the refrigerant pipe are connected by the gas separation pipe.

An air-conditioning apparatus according to another embodiment of the present disclosure includes the above heat exchanger, a fan configured to supply air to the heat exchanger, and a housing that houses the heat exchanger and the fan.

Advantageous Effects of Invention

In the heat exchanger of each of the embodiments of the present disclosure, the first header includes the gas separation space into which gas refrigerant is separated from two-phase gas-liquid refrigerant. Of the two-phase gas-liquid refrigerant that has flowed into the first header, the gas refrigerant is separated from the main flow space into the gas separation space, and the ratio of the gas refrigerant in the main flow space decreases. Thus, in the main flow space, the ratio of liquid refrigerant in the two-phase gas-liquid refrigerant increases, and it is therefore possible to more uniformly distribute the refrigerant from the main flow space to the plurality of heat transfer tubes. As a result, the refrigerant distribution characteristics can be improved without further providing a refrigerant assist device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 1.

FIG. 2 is a refrigerant circuit diagram illustrating the flow of refrigerant in the case where the air-conditioning apparatus according to Embodiment 1 performs a cooling operation.

FIG. 3 is a plan view illustrating one configuration example of a heat-source-side heat exchanger housed in a heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 4 is a plan view illustrating another configuration example of the heat-source-side heat exchanger housed in the heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 5 is a plan view illustrating another configuration example of the heat-source-side heat exchanger housed in the heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 6 is a plan view illustrating a configuration example of a heat-source-side heat exchanger provided in another heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 7 is a plan view illustrating a further configuration example of the heat-source-side heat exchanger of the air-conditioning apparatus according to Embodiment 1; that is, a configuration example of the heat-source-side heat exchanger provided in a further heat source-side unit of air-conditioning apparatus according to Embodiment 1.

FIG. 8 is a plan view illustrating still another configuration example of the heat-source-side heat exchanger of the air-conditioning apparatus according to Embodiment 1, that is, a configuration example of the heat source-side heat exchanger provided in a still another heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 9 is a side view f for explanation the configuration of the heat-source-side heat exchanger according to Embodiment 1.

FIG. 10 is a side view illustrating a configuration example in which heat transfer fins are provided in the heat-source-side heat exchanger as illustrated in FIG. 9.

FIG. 11 is a schematic sectional view illustrating a configuration of part taken along a line A-A in FIG. 9.

FIG. 12 is a schematic view illustrating a configuration example of the inside of a first header as illustrated in FIG. 11.

FIG. 13 is a schematic view illustrating a configuration example of the inside of a first header of Modification 1.

FIG. 14 is a schematic view illustrating a configuration example of the inside of a first header of Modification 2.

FIG. 15 is a schematic view illustrating a configuration example of the inside of a first header of Modification 3.

FIG. 16 is a schematic view illustrating a configuration example of the inside of a first header of Modification 4.

FIG. 17 is a schematic sectional view illustrating a configuration example of the inside of a first header of a heat-source-side heat exchanger according to Embodiment 2.

FIG. 18 is a side view for illustrating a configuration of a heat-source-side heat exchanger according to Embodiment 3.

FIG. 19 is a side view for illustrating a configuration of a heat-source-side heat exchanger according to Embodiment 4.

FIG. 20 is a side view for illustrating a configuration of a heat-source-side heat exchanger according to Embodiment 5.

FIG. 21 is a side view for illustrating a configuration of a heat-source-side heat exchanger according to Embodiment 6.

FIG. 22 is a side view of the heat-source-side heat exchanger as illustrated in FIG. 21 as viewed in another direction.

FIG. 23 is a refrigerant circuit diagram of an air-conditioning apparatus including a heat-source-side heat exchanger according to Embodiment 7.

FIG. 24 is a side view for explanation of a configuration of the heat-source-side heat exchanger according to Embodiment 7.

DESCRIPTION OF EMBODIMENTS

Embodiments of a heat exchanger and an air-conditioning apparatus as described in the present disclosure will be described with reference to the drawings. In each of figures in the drawings, components that are the same as or equivalent to those in a previous figure or previous figures are denoted by the same reference signs, and regarding an embodiment, after components are each described once, their descriptions will not be repeated regarding the other embodiments, that is, their descriptions will be appropriately omitted or simplified. Furthermore, in sectional views of the figures, hatching is appropriately omitted for viewability. In addition, the configurations of components described below regarding each of the embodiments are merely examples, and those descriptions are not limiting. In addition, the shapes, the sizes, and the arrangement of the components as illustrated in the figures can appropriately be modified within the scope of the present disclosure.

In addition, in some of the figures for explanation, arrows along three orthogonal axes (X axis, Y axis, and Z axis) that indicate respective directions are shown. An arrow along the X-axis indicates a width direction, and an arrow along the Y-axis indicates a depth direction; and the opposite direction to the direction indicated by an arrow along the Z-axis is a direction of gravitational force.

Embodiment 1

An air-conditioning apparatus including a heat exchanger according to Embodiment 1 will be described. FIG. 1 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 1. As illustrated in FIG. 1, an air-conditioning apparatus 10 includes a heat-source-side heat exchanger 1, a load-side heat exchanger 2, a compressor 3, an expansion device 4, and a four-way valve 5. The compressor 3, the heat-source-side heat exchanger 1, the expansion device 4, and the load-side heat exchanger 2 are connected by refrigerant pipes 6, whereby a refrigerant circuit 20 is formed in which refrigerant circulates. A gas separation pipe 9 is connected to the heat-source-side heat exchanger 1. The expansion device 4 is, for example, an expansion valve.

The air-conditioning apparatus 10 further includes a heat-source-side fan 7 and a load-side fan 8. The heat-source-side fan 7 sucks outdoor air and supplies the sucked outdoor air to the heat-source-side heat exchanger 1. The load-side fan 8 sucks air in a target space and supplies the sucked air to the load-side heat exchanger 2.

Operation in Heating Operation

The flow of refrigerant in the case where the air-conditioning apparatus 10 performs a heating operation will be described with reference to FIG. 1. Arrows in FIG. 1 indicate the flow direction of the refrigerant.

When being sucked and compressed by the compressor 3, low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant. When being discharged from the compressor 3, the high-temperature and high-pressure gas refrigerant flows through the four-way valve 5 and then flows into the load-side heat exchanger 2. The high-temperature and high-pressure gas refrigerant that has flowed into the load-side heat exchanger 2 exchanges heat with indoor air supplied by the load-side fan 8, and transfers heat to the indoor air to condense and change into high-temperature and high-pressure liquid refrigerant. The high-temperature and high-pressure liquid refrigerant then flows out of the load-side heat exchanger 2. The liquid refrigerant that has flowed out of the load-side heat exchanger 2 is expanded and reduced in pressure by the expansion device 4 to change into low-temperature and low-pressure two-phase gas-liquid refrigerant. The low-temperature and low-pressure two-phase gas-liquid refrigerant flows into the heat-source-side heat exchanger 1. The two-phase gas-liquid refrigerant that has flowed into the heat-source-side heat exchanger 1 exchanges heat with outdoor air supplied by the heat-source-side fan 7, receives heat from the outdoor air, and evaporates to change into low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flows out of the heat-source-side heat exchanger 1. When being re-sucked and compressed by the compressor 3, the low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant, and the high-temperature and high-pressure gas refrigerant is discharged from the compressor 3. The above circulation of the refrigerant is repeated.

Cooling Operation

The flow of the refrigerant in the case where the air-conditioning apparatus 10 performs the cooling operation will be described with reference to FIG. 2. FIG. 2 is a refrigerant circuit diagram illustrating the flow of the refrigerant in the case where the air-conditioning apparatus according to Embodiment 1 performs the cooling operation. Arrows in FIG. 2 indicate the flow direction of the refrigerant.

When being sucked and compressed by the compressor 3, low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant. When being discharged from the compressor 3, the high-temperature and high-pressure gas refrigerant flows through the four-way valve 5 and then flows into the heat-source-side heat exchanger 1. The high-temperature and high-pressure gas refrigerant that has flowed into the heat-source-side heat exchanger 1 exchanges heat with outdoor air supplied by the heat-source-side fan 7 and transfers heat to the outdoor air to condense and change into high-temperature and high-pressure liquid refrigerant, and the high-temperature and high-pressure liquid refrigerant flows out of the heat-source-side heat exchanger 1. The liquid refrigerant that has flowed out of the heat-source-side heat exchanger 1 is expanded and reduced in pressure by the expansion device 4 to change into low-temperature and low-pressure two-phase gas-liquid refrigerant. The low-temperature and low-pressure two-phase gas-liquid refrigerant flows into the load-side heat exchanger 2. The two-phase gas-liquid refrigerant that has flowed into the load-side heat exchanger 2 exchanges heat with indoor air supplied by the load-side fan 8 to receive heat from the indoor air, and thus evaporates and changes into low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flows out of the load-side heat exchanger 2. When being re-sucked and compressed by the compressor 3, the low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant, and the high-temperature and high-pressure gas refrigerant is discharged from the compressor 3. In such a manner, the circulation of the refrigerant is repeated.

Defrosting Operation

The flow of the refrigerant in the case where the air-conditioning apparatus 10 performs a defrosting operation will be described with reference to FIG. 2. Arrows in FIG. 2 each indicate the flow direction of the refrigerant.

When being sucked and compressed by the compressor 3, low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant. Then, when being discharged from the compressor 3, the high-temperature and high-pressure gas refrigerant flows through the four-way valve 5 and then flows into the heat-source-side heat exchanger 1. The high-temperature and high-pressure gas refrigerant that has flowed into the heat-source-side heat exchanger 1 exchanges heat with outdoor air supplied by the heat-source-side fan 7 and with the frost that adheres to an outer surface of the heat-source-side heat exchanger 1, to transfer heat to the frost and condense, and as a result, changes into high-temperature and high-pressure liquid refrigerant. The high-temperature and high-pressure liquid refrigerant then flows out of the heat-source-side heat exchanger 1. The liquid refrigerant that has flowed out of the heat-source-side heat exchanger 1 is expanded and reduced in pressure by the expansion device 4 to change into low-temperature and low-pressure two-phase gas-liquid refrigerant. The low-temperature and low-pressure two-phase gas-liquid refrigerant flows into the load-side heat exchanger 2. The two-phase gas-liquid refrigerant that has flowed into the load-side heat exchanger 2 exchanges heat with indoor air supplied by the load-side fan 8 to receive heat from the indoor air, and as a result, evaporates and changes into low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flows out of the load-side heat exchanger 2. When being re-sucked and compressed by the compressor 3, the low-temperature and low-pressure gas refrigerant changes into high-temperature and high-pressure gas refrigerant, and the high-temperature and high-pressure gas refrigerant is discharged from the compressor 3. In the above manner, the circulation of the refrigerant is repeated.

It should be noted that the number of the heat-source-side heat exchangers 1 and the number of the load-side heat exchangers 2 are not limited to the numbers of those illustrated in FIGS. 1 and 2. The number of the heat-source-side heat exchangers 1 and the number of the load-side heat exchangers 2 may be determined based on the environment of a location where the air-conditioning apparatus 10 is installed or the dimensions of a target space to be air-conditioned by the air-conditioning apparatus 10.

Configuration of Heat-Source-Side Heat Exchanger 1

A configuration of the heat-source-side heat exchanger 1 will be described. Regarding Embodiment 1, the following description is made with respect to the case where the heat-source-side heat exchanger 1 operates as an evaporator, but the heat-source-side heat exchanger 1 may operate as a condenser. When the heat-source-side heat exchanger 1 operates as a condenser, the flow direction of the refrigerant in the refrigerant circuit 20 is opposite to that in the case where the heat-source-side heat exchanger 1 operates as an evaporator. Also, the following description is made with respect to the case where the heat exchanger as described in the present disclosure is the heat-source-side heat exchanger 1, but the load-side heat exchanger 2 may have the same configuration as the heat-source-side heat exchanger 1. In the following description, the heat-source-side heat exchanger 1 and the load-side heat exchanger 2 are sometimes collectively referred to simply as a heat exchanger.

FIG. 3 is a plan view illustrating one configuration example of a heat-source-side heat exchanger provided in a heat source-side unit of the air-conditioning apparatus according to Embodiment 1. FIG. 3 is a plan view of a housing 25 of the heat source-side unit that houses the heat-source-side heat exchanger 1 and the heat-source-side fan 7, as viewed from above. The housing 25 is a top flow-type housing in which, when a propeller of the heat-source-side fan 7 is rotated, air is sucked through four sides of the housing 25 and blown out in the opposite direction to the direction of gravitational force. The planar shape of the housing 25 is a rectangle. In FIG. 3, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant.

The heat-source-side heat exchanger 1 as illustrated in FIG. 3 includes a first heat exchanger 35a and a second heat exchanger 35b. As illustrated in FIG. 3, the heat-source-side fan 7 is provided at the center of the housing 25, and the first heat exchanger 35a and the second heat exchanger 35b are provided along sides of the housing 25. The first heat exchanger 35a and the second heat exchanger 35b include respective bent regions 110 each of which is L-shaped along an associated one of corner portions. At each of the corner portions, two sides of the housing 25 connect with each other, as viewed in the direction of gravitational force.

FIG. 4 is a plan view illustrating another configuration example of the heat-source-side heat exchanger provided in the heat source-side unit of the air-conditioning apparatus according to Embodiment 1. In FIG. 4, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant. The heat-source-side heat exchanger 1 as illustrated in FIG. 4 includes a first heat exchanger 36a and a second heat exchanger 36b. Each of the first heat exchanger 36a and the second heat exchanger 36b includes heat exchangers that extend in plural rows and arranged in the flow direction of air.

The first heat exchanger 36a includes a heat exchanger 131a of the first row, a heat exchanger 132a of the second row, and a connection pipe 27a connecting the heat exchanger 131a of the first row and the heat exchanger 132a of the second row. The heat exchanger 131a of the first row is provided on the windward side, and the heat exchanger 132a of the second row is provided on the leeward side. Each of the heat exchanger 131a of the first row and the heat exchanger 132a of the second row includes the bent region 110 that is L-shaped along an associated one of the corner portions of the housing 25.

The second heat exchanger 36b includes a heat exchanger 131b of the first row, a heat exchanger 132b of the second row, and a connection pipe 27b connecting the heat exchanger 131b of the first row and the heat exchanger 132b of the second row. The heat exchanger 131b of the first row is provided on the windward side, and the heat exchanger 132b of the second row is provided on the leeward side. Each of the heat exchanger 131b of the first row and the heat exchanger 132b of the second row includes the bent region 110 that is L-shaped along an associated one of the corner portions of the housing 25.

FIG. 5 is a plan view illustrating another configuration example of the heat-source-side heat exchanger provided in the heat source-side unit of the air-conditioning apparatus according to Embodiment 1. In FIG. 5, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant. The heat-source-side heat exchanger 1 as illustrated in FIG. 5 includes a first heat exchanger 37a and a second heat exchanger 37b. Each of the first heat exchanger 37a and the second heat exchanger 37b includes heat exchangers that extend in plural rows and that are arranged in the flow direction of air.

The first heat exchanger 37a includes the heat exchanger 131a of the first row and the heat exchanger 132a of the second row but does not include the connection pipe 27a as illustrated in FIG. 4. The heat exchanger 131a of the first row is provided on the windward side, and the heat exchanger 132a of the second row is provided on the leeward side. Each of the heat exchanger 131a of the first row and the heat exchanger 132a of the second row includes the bent region 110 that is L-shaped along an associated one of the corner portions of the housing 25.

The second heat exchanger 36b includes the heat exchanger 131b of the first row and the heat exchanger 132b of the second row but does not include the connection pipe 27b as illustrated in FIG. 4. The heat exchanger 131b of the first row is provided on the windward side, and the heat exchanger 132b of the second row is provided on the leeward side. Each of the heat exchanger 131b of the first row and the heat exchanger 132b of the second row includes the bent region 110 that is L-shaped along an associated one of the corner portions of the housing 25.

As described above, FIG. 4 and FIG. 5 each illustrate the case where in the housing 25 of the heat source-side unit, the plurality of heat exchangers are arranged in the flow direction of air.

Next, the heat-source-side heat exchanger 1 according to Embodiment 1 will be described with respect to the case where a housing different from the housing 25 as Illustrated in FIGS. 3 to 5 is provided. FIG. 6 is a plan view illustrating a configuration example of a heat-source-side heat exchanger provided in another heat source-side unit of the air-conditioning apparatus according to Embodiment 1.

FIG. 6 is a plan view of a housing 26 of the heat source-side unit that includes the compressor 3, the heat-source-side heat exchanger 1, and the heat-source-side fan 7, as viewed from above. The housing 26 is a side flow-type housing in which air is sucked through two of the four sides of the housing 25 and is blown to the outside through one of the four sides, when a propeller of the heat-source-side fan 7 is rotated. The planar shape of the housing 26 is a rectangle. In FIG. 6, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant.

As illustrated in FIG. 6, the heat-source-side fan 7 is provided along one of the four sides of the housing 26, and the heat-source-side heat exchanger 1 is provided along two of the sides of the housing 26. The heat-source-side heat exchanger 1 includes the bent region 110 that is L-shaped along the associated corner portion of the housing 26.

FIG. 7 is a plan view illustrating a further configuration example of the heat-source-side heat exchanger of the air-conditioning apparatus according to Embodiment 1; that is, a configuration example of the heat-source-side heat exchanger provided in a further heat source-side unit of air-conditioning apparatus according to Embodiment 1. In FIG. 7, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant.

The heat-source-side heat exchanger 1 as illustrated in FIG. 7 includes the first heat exchanger 37a and the second heat exchanger 37b that are arranged in the flow direction of air and a connection pipe 28 connecting the first heat exchanger 37a and the second heat exchanger 37b. The first heat exchanger 37a is provided on the windward side, and the second heat exchanger 37b is provided on the leeward side. Each of the first heat exchanger 37a and the second heat exchanger 37b includes the bent region 110 that is L-shaped along the associated corner portion of the housing 26.

FIG. 8 is a plan view illustrating still another configuration example of the heat-source-side heat exchanger of the air-conditioning apparatus according to Embodiment 1, that is, a configuration example of the heat source-side heat exchanger provided in a still another heat source-side unit of the air-conditioning apparatus according to Embodiment 1. In FIG. 8, arrows Dar each indicate the flow direction of air, and arrows Drf each indicate the flow direction of the refrigerant.

The heat-source-side heat exchanger 1 as illustrated in FIG. 8 includes the first heat exchanger 37a and the second heat exchanger 37b that are arranged in the flow direction of air but does not include the connection pipe 28 as illustrated in FIG. 7. The first heat exchanger 37a is provided on the windward side, and the second heat exchanger 37b is provided on the leeward side. Each of the first heat exchanger 37a and the second heat exchanger 37b includes the bent region 110 that is L-shaped along the associated corner portion of the housing 26.

As described above, FIG. 7 and FIG. 8 each illustrate the case where in the housing 26 of the heat source-side unit, the plurality of heat exchangers are arranged in the flow low direction of air.

Although the above descriptions are made with reference to FIGS. 3 to 8 regarding the configuration examples of the heat-source-side heat exchanger 1 including the bent region 110 that is L-shaped in the horizontal direction, the number of bent regions 110 is not limited to the number of bent regions 110 illustrated in FIGS. 3 to 8. The heat-source-side heat exchanger 1 may include two or more bent regions 110 that are located at respective locations. Alternatively, it is allowable that no bent region 110 is included in the heat-source-side heat exchanger 1. In addition, for example, FIG. 3 illustrates a configuration in which the two heat exchangers each including a single bent region 110 are provided in the housing 25; however, the number of the bent regions 110 and the arrangement of the bent regions 110 may be changed, and the number of the heat exchangers and the arrangement of the heat exchangers may be changed.

Next, the configuration of the heat-source-side heat exchanger 1 according to Embodiment 1 and the flow of the refrigerant will be described in detail. FIG. 9 is a side view for explanation of the configuration of the heat-source-side heat exchanger according to Embodiment 1. In FIG. 9, arrows Drf each indicate the flow direction of the refrigerant. The heat-source-side heat exchanger 1 includes the plurality of heat transfer tubes 11 that extend in the direction of gravitational force and that are arranged apart from each other in the horizontal direction orthogonal to the direction of gravitational force, a first header 12, and a second header 13.

The first header 12 is connected to an end portion of each of the plurality of heat transfer tubes 11 in the opposite direction (in the direction along the Z-axis) to the direction of gravitational force. The second header 13 is connected to an end portion of each of the plurality of heat transfer tubes 11 in the direction of gravitational force (the opposite direction opposite to the direction along the Z-axis). In Embodiment 1, the first header 12 is provided to distribute refrigerant that flows thereinto from the expansion device 4 to the plurality of heat transfer tubes 11. The second header 13 is provided to merge refrigerant streams of refrigerant that flow through the plurality of heat transfer tubes 11, into refrigerant. The following description regarding Embodiment 1 is made with respect to the case where the heat transfer tube 11 is a flat tube. However, the heat transfer tube 11 may be a circular tube.

In addition, although it is omitted in FIG. 9, heat transfer fins configured to transfer heat from the refrigerant via the heat transfer tubes 11 are provided in the heat-source-side heat exchanger 1. FIG. 10 is a side view illustrating a configuration example in which heat transfer fins are provided in the heat-source-side heat exchanger as illustrated in FIG. 9. As illustrated in FIG. 10, corrugated fins 19 are provided between adjacent ones of the heat transfer tubes 11 that are arranged apart from each other. The heat transfer fin is not limited to the corrugated fin 19 and may be a plate fin. It is allowable that no heat transfer fins are provided in the heat-source-side heat exchanger 1.

In addition, although it is described as a configuration example with reference to FIG. 9 that the first header 12 serves as a distribution header, the second header 13 serves as a confluence header, and the distribution header and the confluence header are provided in one set, the combination of the headers and the positional relationship between the headers are not limited to those in the configuration example. As described later, the second header 13 may serve as a distribution header. In addition, each of the first header 12 and the second header 13 may be a combination of a distribution header and a confluence header.

Next, the flow of the refrigerant in the heat-source-side heat exchanger 1 will be described with reference to FIGS. 1 to 9. When the heat-source-side heat exchanger 1 operates as an evaporator, two-phase gas-liquid refrigerant that has flowed into the first header 12 through an inlet 22 first flows into a main flow space 15. Of the two-phase gas-liquid refrigerant that has flowed into the main flow space 15, part of gas refrigerant flows into a gas separation space 16 through a first opening 31. The gas refrigerant that has flowed into the gas separation space 16 passes through the gas separation pipe 9 and flows through the refrigerant pipe 6 connected with an outlet 23 of the second header 13. On the other hand, of the two-phase gas-liquid refrigerant that has flowed into the main flow space 15, refrigerant that has not flowed into the gas separation space 16 is distributed to the plurality of heat transfer tubes 11. In the refrigerant distributed to the plurality of heat transfer tubes 11, the ratio of liquid refrigerant is high, because part of the gas refrigerant flows into the gas separation space 16. The two-phase gas-liquid refrigerant distributed to the plurality of heat transfer tubes 11 exchanges heat with air, flows through the heat transfer tubes 11 while evaporating and gasifying, and then flows into the second header 13. In the second header 13, refrigerant streams of gas refrigerant merge into gas refrigerant. The gas refrigerant flows from the second header 13 into the refrigerant pipe 6 through the outlet 23.

FIG. 11 is a schematic sectional view illustrating a configuration of part that is taken along line A-A in FIG. 9. FIG. 11 illustrates a heat transfer tube 11 that is shifted from the part taken along the line A-A, in the direction along the X-axis in FIG. 9, as a matter of convenience for explanation. Arrow Drf in FIG. 11 indicates the flow direction of the refrigerant. The first header 12 is configured such that its internal space is partitioned into the main flow space 15 and the gas separation space 16 by a partition wall 17 that is a plate-shaped member. The gas separation space 16 is provided above the main flow space 15 in the direction along the Z-axis. The partition wall 17 has plural first openings 31 through which the main flow space 15 and the gas separation space 16 communicate with each other and that are spaced from each other in the direction along the X-axis. When the heat-source-side heat exchanger 1 serves as an evaporator, the plural first openings 31 are located at a higher level than the liquid level of liquid refrigerant that flows in the main flow space 15. This is intended to reduce the likelihood that two-phase gas-liquid refrigerant that flows in the main flow space 15 will flow into the gas separation space 16, and also to cause gas refrigerant to be easily separated from the two-phase gas-liquid refrigerant into the gas separation space 16.

In the heat-source-side heat exchanger 1, two-phase gas-liquid refrigerant that has flowed into the first header 12 is affected by the gravity, whereby liquid refrigerant flows mainly in a lower region of the main flow space 15, and gas refrigerant flows mainly in an upper region of the main flow space 15. Thus, the gas refrigerant is separated from the main flow space 15 into the gas separation space 16 through the first openings 31, as a result of which the ratio of gas in the main flow space 15 decreases.

It should be noted that although in the configuration example in FIG. 11, the sectional area of the main flow space 15 is larger than that of the gas separation space 16, the relationship between those sectional areas is not limited to that in the configuration example illustrated in FIG. 11. The sectional area of the gas separation space 16 may be larger than that of the main flow space 15, or may be equal to that of the main flow space 15.

FIG. 12 is a schematic view illustrating a configuration example of the inside of the first header as illustrated in FIG. 11. FIG. 12 illustrates the shape and the positions of the first openings 31 and a positional relationship between the first openings 31 and the heat transfer tubes 11. FIG. 12 illustrates the first header 12 as viewed from above. As illustrated in FIG. 12, the first openings 31 and the heat transfer tubes 11 are alternately arranged. The positional relationship between the first openings 31 and the heat transfer tubes 11 is not limited to that in the configuration as illustrated in FIG. 12. Hereinafter, modifications of the positional relationship between the first openings 31 and the heat transfer tubes 11 will be described.

Modification 1

FIG. 13 is a schematic view illustrating a configuration example of the inside of the first header of Modification 1. As illustrated in FIG. 13, the first openings 31 may be aligned with the respective heat transfer tubes 11.

Modification 2

FIG. 14 is a schematic view illustrating a configuration example of the inside of the first header of Modification 2. As illustrated in FIG. 14, the number of the first openings 31 may be smaller than that of the heat transfer tubes 11. In addition, illustration of the configuration in FIG. 14 is not limiting, and the number of the first openings 31 may be larger than that of the heat transfer tubes 11.

Modification 3

FIG. 15 is a schematic view illustrating a configuration example of the inside of the first header of Modification 3. As illustrated in FIG. 15, the plural first openings 31 may be one-sided. That is, in the configuration example as illustrated in FIG. 15, the plural first openings 31 are provided in a region that is shifted from a central line of the first header 12 in the opposite direction to the direction indicated by the arrow along the X-axis.

Modification 4

FIG. 16 is a schematic view illustrating a configuration example of the inside of the first header of Modification 4. As illustrated in FIG. 16, the first opening 31 may have a flat shape that is longer than the distance between adjacent ones of the heat transfer tubes 11 in the direction along the X-axis.

It should be noted that although FIGS. 12 to 16 illustrate the cases where the first openings 31 are circular or elongated, these illustrations are not limiting. The first openings 31 may be rectangular or polygonal, or may have a shape defined by a closed curve.

The following descriptions are made with respect to the case where the heat-source-side heat exchanger 1 as illustrated in FIG. 9 is applied to the configurations as illustrated in FIGS. 3 to 5. The first one of the descriptions is made with respect to the case where the heat-source-side heat exchanger 1 as illustrated in FIG. 9 is applied to the configuration in FIG. 3. In this case, the first heat exchanger 35a and the second heat exchanger 35b as illustrated in FIG. 3 each have a configuration similar to the configuration of the heat-source-side heat exchanger 1 as illustrated in FIG. 9.

The second one of the descriptions is made with respect to the case where the heat-source-side heat exchanger 1 as illustrated in FIG. 9 is applied to the configuration as illustrated in FIG. 4. In this case, for example, the heat exchanger 131a of the first row and the heat exchanger 132a of the second row in FIG. 4 each have a configuration similar to the configuration of the heat-source-side heat exchanger 1 as illustrated in FIG. 9. The first header 12 of the heat exchanger 131a of the first row and the first header 12 of the heat exchanger 132a of the second row are connected by a connection pipe 27. This connection pipe 27 will be referred to as a first connection pipe. In addition, plural second headers are connected by a connection pipe. The second header 13 of the heat exchanger 131a of the first row and the second header 13 of the heat exchanger 132a of the second row are connected by a connection pipe 27. This connection pipe 27 will be referred to as a second connection pipe. Each of the two first headers 12 connected to each other by the first connection pipe includes the main flow space 15 and the gas separation space 16.

Although it is described with reference to FIG. 4 that the two headers are connected to each other by the connection pipe 27, the heat-source-side heat exchanger 1 as illustrated in FIG. 9 may be bent as the first heat exchanger 36a as illustrated in FIG. 4 is bent, without providing the connection pipe 27a. Also, with such a configuration, the heat exchangers are spaced from each other in the flow direction of air. In this case, the first header 12 of the heat exchanger on the windward side and the first header 12 of the heat exchanger on the leeward side share the gas separation space 16.

Next, the last one of the descriptions is made with respect to the case where the heat-source-side heat exchanger 1 as illustrated in FIG. 9 is applied to the configuration as illustrated in FIG. 5. In this case, for example, the heat exchanger 131a of the first row and the heat exchanger 132a of the second row as illustrated in FIG. 5 each have a similar configuration to the configuration of the heat-source-side heat exchanger 1 as illustrated in FIG. 9. It should be noted that the cases where the heat-source-side heat exchanger 1 as illustrated in FIG. 9 is applied to the configurations as illustrated in FIGS. 6 to 8 are similar to the cases where it is applied to the configurations as illustrated in FIGS. 3 to 5, and their detailed descriptions will thus be omitted.

The heat-source-side heat exchanger 1 of Embodiment 1 includes the plurality of heat transfer tubes 11 that extend in the direction of gravitational force and that are arranged apart from each other in the horizontal direction orthogonal to the direction of gravitational force, the first header 12 connected to the plurality of heat transfer tubes 11 at end portions thereof in the opposite direction to the direction of gravitational force, the second header 13 connected to the plurality of heat transfer tubes 11 at end portions thereof in the direction of gravitational force, and the gas separation pipe 9. The gas separation pipe 9 connects the first header 12 and the refrigerant pipe 6 into which the refrigerant flows out from the second header 13 when the heat-source-side heat exchanger 1 operates as an evaporator. The first header 12 includes the partition wall 17 that partitions an internal space of the first header 12 into plural spaces including the main flow space 15 and the gas separation space 16. The partition wall 17 has the plural first openings 31 through which the main flow space 15 and the gas separation space 16 communicate with each other. The gas separation space 16 is provided above the main flow space 15. The gas separation space 16 is connected with the refrigerant pipe 6 into which the refrigerant flows from the second header 13, by the gas separation pipe 9.

According to Embodiment 1, the first header 12 of the heat-source-side heat exchanger 1 includes the gas separation space 16 into which gas refrigerant is separated from two-phase gas-liquid refrigerant. Of the two-phase gas-liquid refrigerant that has flowed into the first header 12, the gas refrigerant is separated from the main flow space 15 into the gas separation space 16, and the ratio of the gas refrigerant in the main flow space 15 decreases. Thus, in the main flow space 15, the ratio of the liquid refrigerant in the two-phase gas-liquid refrigerant increases, whereby it is possible to more uniformly distribute the refrigerant from the main flow space 15 to the plurality of heat transfer tubes 11. As a result, it is possible to improve the refrigerant distribution characteristics without providing a refrigerant assist device, and improve the heat exchange performance of the heat exchanger. In Embodiment 1, in a header-type refrigerant distributor extending in the horizontal direction, a mechanism for controlling the quality of the two-phase gas-liquid refrigerant is provided as described above, whereby the refrigerant distribution characteristics can be improved

In addition, it is possible to reduce the flow rate of the gas refrigerant that flows in the plurality of heat transfer tubes 11 and the second header 13. Thus, it is possible to reduce a pressure loss of the refrigerant that occurs in the plurality of heat transfer tubes 11 and the second header 13 and improve the performance of the heat exchanger. In particular, when the air-conditioning apparatus 10 is operated under an operation condition that the ratio of the gas refrigerant is high, it is possible to reduce the likelihood that distribution of the refrigerant to the plurality of heat transfer tubes 11 will be worsened, and also to reduce the pressure loss of the refrigerant.

Embodiment 2

In Embodiment 2, the internal configuration of the first header 12 is different from that described regarding Embodiment 1. Regarding Embodiment 2, components that are the same as or equivalent to those described regarding Embodiment 1 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

The configuration of a heat exchanger according to Embodiment 2 will be described. FIG. 17 is a schematic sectional view illustrating a configuration example of the inside of the first header of a heat-source-side heat exchanger according to Embodiment 2. FIG. 17 illustrates a configuration of part taken along the line A-A in FIG. 9, and illustrates a heat transfer tube 11 that is shifted from the part taken along the line A-A, in the direction along the X-axis in FIG. 9, as a matter of convenience for explanation. Arrow Drf in FIG. 17 indicates the flow direction of the refrigerant.

In Embodiment 2, the internal space of the first header 12 is partitioned by the partition wall 17 into the gas separation space 16, main flow spaces 15, and a jet space 18. The partition wall 17 has the plural first openings 31 and plural second openings 32. The plural first openings 31 cause the main flow spaces 15 and the gas separation space 16 to communicate with each other. The plural second openings 32 cause the main flow spaces 15 and the jet space 18 to communicate with each other.

Preferably, each of the plural second openings 32 should not face in the direction indicated by an arrow along the Z-axis in the heat transfer tube 11. To be more specific, the second opening 32 is provided at a position where the second opening 32 does not overlap a plane obtained by projecting, in the opposite direction (the direction indicated by the arrow along the Z-axis) to the direction of gravitational force, a passage cross section of the heat transfer tube 11. This is intended to reduce the likelihood that the refrigerant that jets from each of the main flow spaces 15 into the jet space 18 through the second openings 32 will directly flow into the heat transfer tube 11. In addition, it is preferable that the second openings 32 be located at a boundary between gas and the liquid level of the liquid refrigerant that flows in the main flow space 15. This is intended to reduce the likelihood that the ratio of the gas refrigerant that flows into the jet space 18 will increase.

It should be noted that although FIG. 17 illustrates a configuration in which the first header 12 includes two main flow spaces 15, the number of the main flow spaces 15 is not limited to two. The number of the main flow spaces 15 may be one or may be three or more. In addition, referring to FIG. 17, each of the two second openings 32 faces inward but may be formed in such a manner as to face in the direction indicated by the arrow along the Y-axis or in the opposite direction to the direction indicated by the arrow along the Y-axis.

In the heat-source-side heat exchanger 1 of Embodiment 2, it is possible to equalize the flow rates of refrigerant that jets from the main flow spaces 15 into the jet space 18. Thus, it is possible to more equalize the amounts of the refrigerant that is distributed to the plurality of heat transfer tubes 11. Therefore, the performance of the heat exchanger can be further improved. In addition, it is possible to reduce the amounts of gas refrigerant that flows in the plurality of heat transfer tubes 11 and the second header 13. Thus, the pressure loss of the refrigerant that occurs in the plurality of heat transfer tubes 11 and the second header 13 can be reduced, and the performance of the heat exchanger can be improved.

Embodiment 3

In Embodiment 3, the first header 12 and the second header 13 each have functions of a distribution header and a confluence header. Regarding Embodiment 3, components that are the same as or equivalent to those described regarding Embodiment 1 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

A configuration of a heat exchanger according to Embodiment 3 will be described. FIG. 18 is a side view for illustrating a configuration of a heat-source-side heat exchanger according to Embodiment 3. Arrows Drf in FIG. 18 each indicate the flow direction of the refrigerant.

A heat-source-side heat exchanger 1a includes a first header 12a, a second header 13a, and the plurality of heat transfer tubes 11. The first header 12a includes an upper confluence header 41a and an upper distribution header 42a. When the heat-source-side heat exchanger 1a operates as an evaporator, the upper confluence header 41a merges refrigerant streams of the refrigerant that flow through some of the plurality of heat transfer tubes 11 into refrigerant. The upper distribution header 42a distributes the refrigerant in the upper confluence header 41a to remaining ones of the plurality of heat transfer tubes 11 that are other than the some heat transfer tubes 11.

The second header 13a includes a lower distribution header 44a and a lower confluence header 43a. When the heat-source-side heat exchanger 1a operates as an evaporator, the lower distribution header 44a distributes refrigerant that flows thereinto through an inlet 22 to some of the plurality of heat transfer tubes 11. The lower confluence header 43a merges refrigerant streams of refrigerant that flow from the upper distribution header 42a to the remaining ones of the heat transfer tubes 11. In the second header 13a, a partition portion 24 is provided between the lower distribution header 44a and the lower confluence header 43a. In the first header 12a, the upper confluence header 41a and the upper distribution header 42a share the gas separation space 16.

The flow of the refrigerant in the heat-source-side heat exchanger 1a of Embodiment 3 will be described. The refrigerant flows into the lower distribution header 44a of the second header 13a, flows through some heat transfer tubes 11 while being evaporated and gasified, and flows into the upper confluence header 41a. The two-phase gas-liquid refrigerant that has flowed into the upper confluence header 41a flows into the upper distribution header 42a adjacent thereto. Because the upper confluence header 41a and the upper distribution header 42a include the gas separation space 16 as a common gas separation space, in the gas separation space 18, the gas refrigerant is separated from the two-phase gas-liquid refrigerant.

In the heat-source-side heat exchanger 1a of Embodiment 3, of the two-phase gas-liquid refrigerant that has flowed into the first header 12a, the gas refrigerant is separated from the main flow space 15 into the gas separation space 16, and the ratio of the gas refrigerant in the main flow space 15 decreases. Thus, in the main flow space 15, the ratio of the liquid refrigerant in the two-phase gas-liquid refrigerant increases, and it is therefore possible to more uniformize the distribution of the refrigerant from the main flow space 15 to the plurality of heat transfer tubes 11. Therefore, the performance of the heat exchanger can be improved. In addition, the flow rate of the gas refrigerant that flows in the remaining heat transfer tubes 11 and the lower confluence header 43a can be decreased. Thus, the pressure loss of the refrigerant that occurs in the remaining heat transfer tubes 11 and the lower confluence header 43a can be reduced, and the performance of the heat exchanger can be improved. In particular, it should be noted that gas refrigerant is separated in the upper confluence header 41a, and the flow rate of the gas refrigerant decreases in a stage where the refrigerant flows into the upper distribution header 42a adjacent to the upper confluence header 41a, whereby the pressure loss of the refrigerant can be further reduced.

Embodiment 4

In Embodiment 4, the first header 12 and the second header 13 each have functions of a distribution header and a confluence header but have configurations different from those in Embodiment 3. Regarding Embodiment 4, components that are the same as or equivalent to those described regarding any of Embodiments 1 to 3 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

The configuration of a heat exchanger of Embodiment 4 will be described. FIG. 19 is a side view for explanation of a configuration of a heat-source-side heat exchanger according to Embodiment 4. Arrows Drf in FIG. 19 each indicate the flow direction of the refrigerant.

A heat-source-side heat exchanger 1b includes a first header 12b, a second header 13b, and the plurality of heat transfer tubes 11. The first header 12b includes an upper confluence header 41b and an upper distribution header 42b. When the heat-source-side heat exchanger 1b operates as an evaporator, the upper confluence header 41b merges refrigerant streams of refrigerant that flow through some of the plurality of heat transfer tubes 11 into refrigerant. The upper distribution header 42b distributes the refrigerant obtained in the upper confluence header 41b to remaining ones of the plurality of heat transfer tubes 11 that are other than the some heat transfer tubes 11.

The second header 13b includes a lower distribution header 44b and a lower confluence header 43b. When the heat-source-side heat exchanger 1b operates as an evaporator, the lower distribution header 44b distributes refrigerant that flows thereinto through an inlet 22 to some of the plurality of heat transfer tubes 11. The lower confluence header 43b merges refrigerant streams of refrigerant that flow from the upper distribution header 42b to the remaining ones of the heat transfer tubes 11. The upper confluence header 41b includes a gas separation space 16 and a main flow space 15, whereas the upper distribution header 42b includes only a main flow space 15. The passage sectional area of the main flow space 15 of the upper distribution header 42b is smaller than that of the main flow space 15 of the upper confluence header 41b.

In the heat-source-side heat exchanger 1b of Embodiment 4, in the upper confluence header 41b, gas refrigerant is separated, thereby decreasing the refrigerant flow velocity, and the decreased refrigerant flow velocity can be increased in the upper distribution header 42b adjacent to the upper confluence header 41b. Thus, in the upper distribution header 42b, it is possible to reduce the likelihood that the refrigerant distribution characteristics will be worsened by a decrease in the flow velocity. In addition, it is possible to reduce the mass of components that form the first header 12b, and improve the cost performance of the heat-source-side heat exchanger 1b.

Embodiment 5

In Embodiment 5, the first header 12 and the second header 13 each have functions of a distribution header and a confluence header but have configurations different from those in Embodiments 3 and 4. Regarding Embodiment 5, components that are the same as or equivalent to those described regarding any of Embodiments 1 to 4 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

The configuration of a heat exchanger of Embodiment 5 will be described. FIG. 20 is a side view for explanation of the configuration of a heat-source-side heat exchanger according to Embodiment 5. Arrows Drf in FIG. 20 each indicate the flow direction of the refrigerant.

A heat-source-side heat exchanger 1c includes a first header 12c, a second header 13c, and the plurality of heat transfer tubes 11. The first header 12c includes an upper confluence header 41c and an upper distribution header 42c. When the heat-source-side heat exchanger 1c operates as an evaporator, the upper confluence header 41c merges refrigerant streams of refrigerant that flows through some of the plurality of heat transfer tubes 11 into refrigerant. The upper distribution header 42c distributes the refrigerant obtained in the upper confluence header 41c to remaining ones of the plurality of heat transfer tubes 11 that are other than the some heat transfer tubes 11. In the first header 12c, the upper confluence header 41c and the upper distribution header 42c share the main flow space 15. In the first header 12c, the partition portion 24 is provided between a refrigerant inlet and the upper confluence header 41c.

The second header 13c includes a lower distribution header 44c and a lower confluence header 43c. When the heat-source-side heat exchanger 1c operates as an evaporator, the lower distribution header 44c distributes refrigerant that flows thereinto to some of the plurality of heat transfer tubes 11. The lower confluence header 43c merges refrigerant streams of refrigerant that flow from the upper distribution header 42c into the remaining heat transfer tubes 11, into refrigerant. In the second header 13c, the partition portion 24 is provided between the lower distribution header 44c and the lower confluence header 43c.

The heat-source-side heat exchanger 1c includes one or more bent regions 110 as illustrated in FIGS. 3 to 8. Referring to FIG. 20, a heat exchange portion that includes the upper distribution header 42c, the lower confluence header 43c, two or more heat transfer tubes 11 connected to the upper distribution header 42c and the lower confluence header 43c is located in the bent region 110. In the heat-source-side heat exchanger 1c, the upper confluence header 41c that is located upstream of the bent region 110 in the flow direction of the refrigerant includes the gas separation space 16 and the main flow space 15.

The flow of refrigerant in the heat-source-side heat exchanger 1c of Embodiment 5 will be described. In the upper confluence header 41c located upstream of the bent region 110, of refrigerant that has flowed from the lower distribution header 44c into the upper confluence header 41c, part of gas refrigerant is separated into the gas separation space 16. Subsequently, refrigerant in which the ratio of liquid refrigerant is high flows into the upper distribution header 42c where the bent region 110 is located, and then flows into two or more heat transfer tubes 11.

In an existing configuration, when refrigerant in which the ratio of gas refrigerant is high flows into the bent region 110, a centrifugal force acts on the refrigerant in the bent region 110 and as a result, the refrigerant is nonuniformly distributed, thereby reducing the performance of the heat exchanger. In contrast, in the heat-source-side heat exchanger 1c of Embodiment 5, refrigerant in which the ratio of gas refrigerant is low flows into the upper distribution header 42c located in the bent region 110. It is therefore possible to reduce the likelihood that distribution of the refrigerant to the heat transfer tubes 11 will be worsened. It is therefore possible to reduce deterioration of the performance of the heat exchanger that occurs in the bent region 110.

Embodiment 6

A heat exchanger according to Embodiment 6 includes a plurality of heat exchangers that are arranged apart from each other in the flow direction of air. Regarding Embodiment 6, components that are the same as or equivalent to those described regarding any of Embodiments 1 to 5 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

A configuration of the heat exchanger according to Embodiment 6 will be described. FIG. 21 is a side view for explanation of the configuration of a heat-source-side heat exchanger according to Embodiment 6. FIG. 22 is a side view of the heat-source-side heat exchanger as illustrated in FIG. 21 as viewed in another direction. Arrows Drf in each of FIGS. 21 and 22 each indicate the flow direction of the refrigerant. Arrow Dar in FIG. 22 indicates the flow direction of air.

A heat-source-side heat exchanger 1d includes: a heat exchanger that includes a first header 12-1, the plurality of heat transfer tubes 11, and a second header 13-1; and a heat exchanger that includes a first header 12-2, the plurality of heat transfer tubes 11, and a second header 13-2. As illustrated in FIG. 22, those heat exchangers are arranged apart from each other in the flow direction of air.

The heat-source-side heat exchanger 1d includes a connection header 14 that includes the first headers 12-1 and 12-2 and that is formed as a single body in which the first headers 12-1 and 12-2 are connected to each other. The second header 13-1 serves as a distribution header that distributes the refrigerant to the plurality of heat transfer tubes 11. The second header 13-2 serves as a confluence header that merges refrigerant streams of refrigerant that flow from the connection header 14 to the plurality of heat transfer tubes 11, into refrigerant. The connection header 14 includes the main flow space 15 and the gas separation space 16.

In the heat-source-side heat exchanger 1d according to Embodiment 6, in the connection header 14, refrigerant in which the ratio of gas refrigerant has increased can be varied such that the ratio of the gas refrigerant is reduced. It is therefore possible to uniformly distribute the refrigerant to the plurality of heat transfer tubes 11 located downstream of the connection header 14, and improve the performance of the heat exchanger. It is also possible to reduce the flow rate of gas refrigerant that flows in the second header 13-2 and the plurality of heat transfer tubes 11 connected to the second header 13-2. Thus, it is possible to reduce the pressure loss of the refrigerant that occurs in the second header 13-2 and the plurality of heat transfer tubes 11 connected to the second header 13-2, and improve the performance of the heat exchanger.

Embodiment 7

In Embodiment 7, the flow rate of gas refrigerant that flows out of the gas separation space 16 of the first header 12 can be regulated. Regarding Embodiment 7, components that are the same as or equivalent to those described regarding any of Embodiments 1 to 6 will be denoted by the same reference sigs, and their detailed descriptions will thus be omitted.

A configuration of a heat exchanger of Embodiment 7 will be described. FIG. 23 is a refrigerant circuit diagram of an air-conditioning apparatus including a heat-source-side heat exchanger according to Embodiment 7. FIG. 24 is a side view for explanation of a configuration of the heat-source-side heat exchanger according to Embodiment 7. Arrows Drf in FIG. 24 each indicate the flow direction of the refrigerant.

A heat-source-side heat exchanger 1e according to Embodiment 7 includes a gas separation expansion device 21 provided at a gas separation pipe 9. The gas separation expansion device 21 is, for example, a thermal expansion valve. The gas separation expansion device 21 regulates the flow rate of gas refrigerant.

Gas refrigerant that is separated from two-phase gas-liquid refrigerant passes through the gas separation expansion device 21 and then flows into the refrigerant pipe 6 at the outlet 23 of the second header 13. The gas separation expansion device 21 regulates the flow rate of the separated gas refrigerant by controlling its opening degree. For example, when the heat-source-side heat exchanger 1e operates as a condenser, the gas separation expansion device 21 is in a closed state, and when the heat-source-side heat exchanger 1e operates as an evaporator, the gas separation expansion device 21 is in an opened state. In addition, when the ratio of the gas refrigerant is increased during the heating operation by an air-conditioning apparatus 10a, it is possible to regulate the amount of gas refrigerant to be separated, by further increasing the opening degree of the gas separation expansion device 21.

When the heat-source-side heat exchanger 1e of the Embodiment 7 operates as an evaporator, it is possible to regulate the flow rate of gas to be separated, according to the quality of refrigerant that flows into the heat-source-side heat exchanger 1e. It is therefore possible to uniformize distribution of the refrigerant under a wider range of operation conditions, and further improve the performance of the heat exchanger.

It should be noted that Embodiments 1 to 7 are described above as examples in order to explain the heat exchanger and the air-conditioning apparatus of the present disclosure, and of Embodiments 1 to 7, two or more embodiments may be combined to solve the above problem.

REFERENCE SIGNS LIST

1, 1a to 1e: heat-source-side heat exchanger, 2: load-side heat exchanger, 3: compressor, 4: expansion device, 5: four-way valve, 6: refrigerant pipe, 7: heat-source-side fan, 8: load-side fan, 9: gas separation pipe, 10, 10a: air-conditioning apparatus, 11: heat transfer tube, 12, 12-1, 12-2, 12a to 12c: first header, 13, 13-1, 13-2, 13a to 13c: second header, 14: connection header, 15: main flow space, 16: gas separation space, 17: partition wall, 18: jet space, 19: corrugated fin, 20: refrigerant circuit, 21: gas separation expansion device, 22: inlet, 23: outlet, 24: partition portion, 25, 26: housing, 27, 27a, 27b, 28: connection pipe, 31: first opening, 32: second opening, 35a to 37a: first heat exchanger, 35b to 37b: second heat exchanger, 41a to 41c: upper confluence header, 42a to 42c: upper distribution header, 43a to 43c: lower confluence header, 44a to 44c: lower distribution header, 110: bent region, 131a, 131b: heat exchanger of first row, 132a, 132b: heat exchanger of second row, Dar, Drf: arrow

Claims

1. A heat exchanger that causes heat exchange to be performed between air and refrigerant, the heat exchanger comprising:

a plurality of heat transfer tubes that extend in a direction of gravitational force, the plurality of heat transfer tubes being arranged apart from each other in a horizontal direction orthogonal to the direction of gravitational force;

a first header connected to the plurality of heat transfer tubes at end portions thereof in an opposite direction to the direction of gravitational force;

a second header connected to the plurality of heat transfer tubes at end portions thereof in the direction of gravitational force; and

a gas separation pipe connecting the first header and a refrigerant pipe through which the refrigerant flows out of the second header when the heat exchanger operates as an evaporator,

wherein

the first header includes a partition wall that partitions an internal space of the first header into a plurality of spaces including a main flow space and a gas separation space,

the partition wall has a plurality of first openings through which the main flow space and the gas separation space communicate with each other,

the gas separation space is located above the main flow space, and

the gas separation space and the refrigerant pipe are connected by the gas separation pipe.

2. The heat exchanger of claim 1, wherein the plurality of first openings are each provided at a higher position than a liquid level of the refrigerant that flows as liquid refrigerant in the main flow space when the heat exchanger operates as an evaporator.

3. The heat exchanger of claim 1, wherein

the partition wall partitions the internal space of the first header into the main flow space, the gas separation space, and a jet space,

the partition wall has a plurality of second openings through which the main flow space and the jet space communicate with each other, and

each of the plurality of second openings is located at a boundary between gas and a liquid level of the refrigerant that flows as liquid refrigerant in the main flow space and is provided at a position where the second opening does not overlap a plane obtained by projecting a passage cross section of each of the heat transfer tubes in the opposite direction to the direction of gravitational force.

4. The heat exchanger of claim 1, wherein

the first header includes an upper confluence header and an upper distribution header, the upper confluence header being configured to merge refrigerant streams of refrigerant that flow through some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, into refrigerant, the upper distribution header being configured to distribute the refrigerant in the upper confluence header to remaining ones of the plurality of heat transfer tubes that are other than the some of the plurality of heat transfer tubes,

the second header includes a lower distribution header and a lower confluence header, the lower distributor header being configured to distribute the refrigerant to the some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, the lower confluence header being configured to merge refrigerant streams of the refrigerant that flow from the upper distribution header to the remaining ones of the plurality of heat transfer tubes, into refrigerant,

in the second header, a partition portion is provided between the lower distribution header and the lower confluence header, and

in the first header, the upper confluence header and the upper distribution header share the gas separation space.

5. The heat exchanger of claim 1, wherein

the first header includes an upper confluence header and an upper distribution header, the upper confluence header being configured to merge refrigerant streams of refrigerant that flow through some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, into refrigerant, the upper distribution header being configured to distribute the refrigerant in the upper confluence header to remaining ones of the plurality of heat transfer tubes that are other than the some of the plurality of heat transfer tubes,

the second header includes a lower distribution header and a lower confluence header, the lower distribution header being configured to distribute the refrigerant to the some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, the lower confluence header being configured to merge refrigerant streams of refrigerant that flow from the upper distribution header to the remaining ones of the plurality of heat transfer tubes, into refrigerant,

the upper confluence header includes a plurality of spaces including the gas separation space and the main flow space,

the upper distribution header includes only the main flow space, and

the main flow space of the upper distribution header has a passage sectional area that is smaller than a passage sectional area of the main flow space of the upper confluence header.

6. The heat exchanger of claim 1, further comprising:

a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air; and

a connection header including a plurality of the first headers and formed as a single body in which the first headers are connected to each other,

wherein

one of a plurality of the second headers is a distribution header configured to distribute the refrigerant to the plurality of heat transfer tubes, and another one of the second headers is a confluence header configured to merge refrigerant streams of refrigerant that flow from the connection header to the plurality of heat transfer tubes, into refrigerant, and

the connection header includes a plurality of spaces including the main flow space and the gas separation space.

7. The heat exchanger of claim 1, further comprising:

a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air; and

a first connection pipe connecting a plurality of the first headers to each other; and

a second connection pipe connecting a plurality of the second headers to each other,

wherein the first headers each include the main flow space and the gas separation space.

8. The heat exchanger of claim 1, further comprising a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air,

wherein the first headers share the gas separation space.

9. The heat exchanger of claim 1, further comprising a gas separation expansion device provided at the gas separation pipe and configured to regulate a flow rate of the refrigerant that flows as gas refrigerant.

10. An air-conditioning apparatus comprising:

the heat exchanger of claim 1;

a fan configured to supply the air to the heat exchanger; and

a housing the heat exchanger and the fan.

11. The air-conditioning apparatus of claim 10, wherein

the heat exchanger includes a bent region that is bent along a corner portion at which two sides of the housing connect with each other as viewed in the direction of gravitational force, and

the gas separation space is provided upstream of the bent region in a flow direction of the refrigerant when the heat exchanger operates as the evaporator.