JP7670600B2 - Heat exchanger and air conditioning device - Google Patents

Description

Embodiments of the present invention relate to a heat exchanger and an air conditioning device.

Air conditioning devices such as air conditioners adjust the indoor temperature by condensing and evaporating the refrigerant in a refrigeration cycle. For example, during cooling operation, the refrigerant condenses in the outdoor heat exchanger and evaporates in the indoor heat exchanger. In such heat exchangers, if the refrigerant exists in a separated liquid and gas state, the heat exchange performance decreases, so technology has been proposed to suppress the separation of liquid and gas.

Japanese Patent Application Publication No. 11-337293

The capacity of a heat exchanger is determined by the amount of heat transfer, and is therefore determined by the size of the heat exchanger. In other words, in order to improve the cooling and heating capabilities of an air conditioning system, a large heat exchanger is required. However, increasing the size of the heat exchanger has been an obstacle to making indoor and outdoor units smaller. In addition, by reducing the diameter of the flow paths through which the refrigerant flows in the heat exchanger and by making them multiple, it is possible to improve the heat exchange efficiency while preventing the heat exchanger from becoming larger. However, as the flow paths become thinner, it becomes more difficult to distribute the liquid and gaseous refrigerant to each flow path, and there is a problem in that it is difficult to achieve the effect of dividing the flow paths into smaller ones.

One example of the problem that the present invention solves is to provide a heat exchanger and an air conditioner that can improve operating performance while reducing the size of the heat exchanger.

A heat exchanger according to one embodiment of the present invention includes a first tube group, a second tube group, a support portion, a first throttle opening, and a second throttle opening. The first tube group is made up of a plurality of first thin tubes through which a refrigerant can flow in one direction. The second tube group is made up of a second thin tube through which the refrigerant can flow in a direction different from that of the first thin tubes. The support portion has a communication chamber that communicates the first thin tube and the second thin tube. The first throttle opening is provided in a first connection wall to which the first thin tube of the support portion is connected, and has an area smaller than the pipe cross-sectional area of the first thin tube. The second throttle opening is provided in a second connection wall to which the second thin tube of the support portion is connected, and has an area smaller than the pipe cross-sectional area of the second thin tube. The first throttle opening is open in the first connection wall at a lower area side of the pipe cross section in a direction perpendicular to the flow direction of the refrigerant in the first thin tube. The second throttle opening is open in the second connecting wall toward a lower region side of a pipe cross section in a direction perpendicular to a flow direction of the refrigerant in the second small diameter tube.

The communication chamber of the heat exchanger may also include, for example, a partition wall between the first and second throttling openings, the partition wall having a third throttling opening with an area smaller than the cross-sectional area of the flow passage of the communication chamber.

Furthermore, the third throttle opening of the heat exchanger may be formed, for example, at a position including the center of the partition wall.

The communication chamber of the heat exchanger may also include, for example, an auxiliary partition wall having at least one fourth throttle opening at a position offset from the position where the third throttle opening of the partition wall is formed.

The communication chamber of the heat exchanger may also include, for example, an opposing wall portion that blocks the flow direction of the refrigerant passing through the first throttling opening, the second throttling opening, and the third throttling opening.

The heat exchanger may also be provided in at least one of the indoor and outdoor units of an air conditioner.

According to the above heat exchanger, for example, the first and second throttling sections can increase the speed of the refrigerant flowing through the first and second thin tubes, and the medium with increased speed flows into the communication chamber, causing turbulence in the communication chamber. As a result, the liquid medium and the gaseous medium are mixed, and the medium flowing into the first or second thin tube downstream across the communication chamber is easily homogenized. In addition, the flow speed of the medium flowing through the first or second thin tube downstream is increased, further improving the heat exchange efficiency.

FIG. 1 is a refrigerant system diagram of an air conditioner equipped with a heat exchanger according to this embodiment, and is an exemplary schematic diagram showing the flow of refrigerant during cooling operation. FIG. 2 is a refrigerant system diagram of an air conditioner including a heat exchanger according to this embodiment, and is an exemplary schematic diagram showing the flow of refrigerant during heating operation. FIG. 3 is an exemplary schematic cross-sectional block diagram functionally illustrating the configuration of an air-conditioning apparatus including the heat exchanger of this embodiment. FIG. 4 is an exemplary schematic perspective view showing the overall configuration of the heat exchanger of the present embodiment. FIG. 5 is an illustrative schematic cross-sectional view showing an indoor unit of an air conditioner equipped with the heat exchanger of the present embodiment. FIG. 6 is an exemplary schematic cross-sectional view showing details of the heat exchanger according to the present embodiment. FIG. 7 is an exemplary schematic cross-sectional view showing details of the support portion of FIG. 6. As shown in FIG. FIG. 8 is an exemplary flowchart showing the flow of cooling operation control of an air conditioner including the heat exchanger of this embodiment. FIG. 9 is an exemplary flowchart showing the flow of heating operation control of an air conditioner including the heat exchanger of this embodiment. FIG. 10 is an exemplary schematic diagram showing another refrigerant system diagram of an air conditioner in which the heat exchanger according to the present embodiment can be mounted.

One embodiment will be described below with reference to Figs. 1 to 9. Note that in this specification, components according to the embodiment and descriptions of the components may be described in multiple ways. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. The components may also be described by expressions different from those in this specification.

Figure 1 is a refrigerant system diagram of an air conditioner 10 equipped with a heat exchanger according to this embodiment, and is an exemplary and schematic diagram showing the flow of refrigerant during cooling operation. The air conditioner 10 is, for example, a home air conditioner. Note that the air conditioner 10 is not limited to this example, and may be other air conditioners such as a commercial air conditioner.

As shown in FIG. 1, the air conditioning device 10 has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is placed, for example, outdoors. The indoor unit 12 is placed, for example, indoors.

The air conditioning device 10 has a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. Refrigerant flows between the outdoor unit 11 and the indoor unit 12 through the refrigerant piping 13. In addition, the outdoor unit 11 and the indoor unit 12 are electrically connected to each other, for example, by electrical wiring.

The outdoor unit 11 has an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, a first expansion valve 31, a second expansion valve 32, a third expansion valve 33, a gas-liquid separator 34, a switching valve 35, a first check valve 36, and a second check valve 37. The indoor unit 12 has an indoor heat exchanger 41 and an indoor blower fan 42.

The refrigerant pipe 13 is a pipe made of a metal such as copper or aluminum. The refrigerant pipe 13 has a first pipe 51, a second pipe 52, and a third pipe 53. The first pipe 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. The compressor 23, the accumulator 24, the four-way valve 25, the third expansion valve 33, the switching valve 35, and the first check valve 36 are provided in the first pipe 51. The second pipe 52 connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The first expansion valve 31, the second expansion valve 32, and the gas-liquid separator 34 are provided in the second pipe 52. The third pipe 53 is connected to the first pipe 51. The second check valve 37 is provided in the third pipe 53.

During cooling operation, the refrigerant flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the first pipe 51, and flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the second pipe 52. The arrows in Figure 1 show the flow of the refrigerant during cooling operation.

Figure 2 is a refrigerant system diagram of an air conditioning device 10 equipped with a heat exchanger according to this embodiment, and is an exemplary and schematic diagram showing the flow of refrigerant during heating operation. As shown in Figure 2, during heating operation, the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the first pipe 51, and flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the second pipe 52. The arrows in Figure 2 indicate the flow of refrigerant during heating operation.

The outdoor heat exchanger 21 of the outdoor unit 11 acts as an evaporator to absorb heat from the refrigerant or as a condenser to release heat from the refrigerant depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air toward the outdoor heat exchanger 21, promoting heat exchange between the refrigerant and air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the outdoor heat exchanger 21.

The compressor 23 has an intake port 23a and an exhaust port 23b. The compressor 23 draws in the refrigerant from the intake port 23a and exhausts the compressed refrigerant from the exhaust port 23b. In this way, the compressor 23 compresses the refrigerant in the refrigeration cycle and causes the refrigerant to circulate.

The accumulator 24 is connected to the suction port 23a of the compressor 23. The accumulator 24 separates the gaseous refrigerant from the liquid refrigerant. This allows the compressor 23 to suck the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can also function as the suction port of the compressor 23 by being configured integrally with the compressor 23.

The four-way valve 25 is connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23, and the accumulator 24 (the suction port 23a of the compressor 23). The four-way valve 25 switches the flow paths connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23, and the accumulator 24 during heating operation and cooling operation, changing the direction in which the refrigerant flows.

As shown in FIG. 1, during cooling operation, the four-way valve 25 connects the outdoor heat exchanger 21 to the discharge port 23b of the compressor 23. Furthermore, during cooling operation, the four-way valve 25 connects the indoor heat exchanger 41 to the accumulator 24. As a result, the refrigerant compressed by the compressor 23 flows to the outdoor heat exchanger 21, and the refrigerant that has undergone heat exchange (e.g. evaporated) in the indoor heat exchanger 41 flows to the accumulator 24.

As shown in FIG. 2, during heating operation, the four-way valve 25 connects the outdoor heat exchanger 21 and the accumulator 24. Furthermore, during heating operation, the four-way valve 25 connects the indoor heat exchanger 41 and the discharge port 23b of the compressor 23. As a result, the refrigerant compressed by the compressor 23 flows to the indoor heat exchanger 41, and the refrigerant that has undergone heat exchange (e.g. evaporated) in the outdoor heat exchanger 21 flows to the accumulator 24.

The first expansion valve 31, the second expansion valve 32, and the third expansion valve 33 are, for example, electromagnetic expansion valves. Note that the first expansion valve 31, the second expansion valve 32, and the third expansion valve 33 may be other expansion valves. The first expansion valve 31, the second expansion valve 32, and the third expansion valve 33 adjust the amount of refrigerant passing through by controlling the opening degree.

The gas-liquid separator 34 separates the two-phase gas-liquid refrigerant flowing in from the first expansion valve 31 side during cooling operation, and the two-phase gas-liquid refrigerant flowing in from the second expansion valve 32 side during heating operation, into a liquid medium and a gas medium. During cooling operation, the liquid refrigerant is sent to the indoor heat exchanger 41 side. During heating operation, the liquid refrigerant is sent to the outdoor heat exchanger 21 side. The separated gas refrigerant is sent to the compressor 23 via the accumulator 24.

The indoor heat exchanger 41 of the indoor unit 12 absorbs heat as an evaporator or releases heat as a condenser depending on the direction of refrigerant flow. The indoor blower fan 42 blows air toward the indoor heat exchanger 41, promoting heat exchange between the indoor heat exchanger 41 and the air. In other words, the indoor blower fan 42 generates an airflow that exchanges heat with the indoor heat exchanger 41.

In the air conditioning device 10 in which the elements are arranged as described above, the first piping 51 has a first region 51a, a second region 51b, a third region 51c, and a fourth region 51d. The first region 51a is a portion of the first piping 51 between the indoor heat exchanger 41 and the four-way valve 25. The second region 51b is a portion of the first piping 51 between the four-way valve 25 and the accumulator 24. The third region 51c is a portion of the first piping 51 between the discharge port 23b of the compressor 23 and the four-way valve 25. The fourth region 51d is a portion of the first piping 51 between the four-way valve 25 and the outdoor heat exchanger 21.

The second piping 52 has a fifth region 52a, a sixth region 52b, a seventh region 52c, and an eighth region 52d. The fifth region 52a is a part of the second piping 52 between the outdoor heat exchanger 21 and the first expansion valve 31. The sixth region 52b is a part of the second piping 52 between the second expansion valve 32 and the indoor heat exchanger 41. The seventh region 52c is a part of the second piping 52 between the first expansion valve 31 and the gas-liquid separator 34. The eighth region 52d is a part of the second piping 52 between the second expansion valve 32 and the gas-liquid separator 34.

The third expansion valve 33 is provided in the second region 51b of the first pipe 51. In other words, the third expansion valve 33 is provided in the first pipe 51 between the four-way valve 25 and the intake port 23a (accumulator 24) of the compressor 23.

The switching valve 35 is, for example, a three-way valve. Note that the switching valve 35 may be another switching valve capable of changing the direction in which the refrigerant flows, such as a four-way valve. The switching valve 35 is provided in the second region 51b of the first pipe 51 between the third expansion valve 33 and the suction port 23a (accumulator 24) of the compressor 23.

The third pipe 53 is connected to the second region 51b of the first pipe 51. The first end 53a of the third pipe 53 is connected to the switching valve 35. That is, the switching valve 35 is provided at the connection between the first end 53a of the third pipe 53 and the first pipe 51. The second end 53b of the third pipe 53 is connected to the first pipe 51 between the switching valve 35 and the suction port 23a (accumulator 24) of the compressor 23. The first end 53a is an example of one end of the third pipe. The second end 53b is an example of the other end of the third pipe.

The switching valve 35 switches the flow paths connected to the four-way valve 25, the suction port 23a (accumulator 24) of the compressor 23, and the third pipe 53, and changes the direction in which the refrigerant flows. That is, the switching valve 35 can direct the refrigerant flowing from the four-way valve 25 toward the suction port 23a (accumulator 24) of the compressor 23 via the third pipe 53 to the suction port 23a (accumulator 24) of the compressor 23.

The first check valve 36 is provided in the first pipe 51 between the switching valve 35 and the second end 53b of the third pipe 53. The first check valve 36 allows the refrigerant flowing in the direction from the switching valve 35 toward the suction port 23a (accumulator 24) of the compressor 23 to pass through. On the other hand, the first check valve 36 blocks the refrigerant flowing in the direction from the suction port 23a (accumulator 24) of the compressor 23 toward the switching valve 35.

The second check valve 37 is provided in the third pipe 53 between the switching valve 35 and the second end 53b of the third pipe 53. The second check valve 37 allows the refrigerant flowing in the direction from the switching valve 35 toward the suction port 23a (accumulator 24) of the compressor 23 to pass. On the other hand, the second check valve 37 blocks the refrigerant flowing in the direction from the suction port 23a (accumulator 24) of the compressor 23 toward the switching valve 35.

The outdoor unit 11 of this embodiment has a first heat storage material 61, a second heat storage material 62, and a third heat storage material 63. The outdoor unit 11 also has a first temperature sensor 71, a second temperature sensor 72, a third temperature sensor 73, a fourth temperature sensor 74, a fifth temperature sensor 75, a sixth temperature sensor 76, a seventh temperature sensor 77, an eighth temperature sensor 78, a ninth temperature sensor 79, and a tenth temperature sensor 80. The first heat storage material 61 is an example of a first heat transfer section. The second heat storage material 62 is an example of a second heat transfer section. The third heat storage material 63 is an example of a heat storage material.

The first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 each have, for example, a latent heat storage material filled in a block-shaped container. The latent heat storage material is, for example, calcium chloride. The first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 may have another latent heat storage material. The first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 in this embodiment are, for example, heat storage materials that can be used in a temperature range of about 10°C to about 100°C.

The first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 are not limited to the above examples, and may be, for example, other heat storage materials such as sensible heat storage materials, or may be heat storage materials that can be used in other temperature ranges. In addition, the first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 may be different heat storage materials from each other.

The first heat storage material 61 is thermally connected to the second region 51b of the first pipe 51 between the third expansion valve 33 and the intake port 23a (accumulator 24) of the compressor 23. In this embodiment, the first heat storage material 61 is thermally connected to the first pipe 51 between the switching valve 35 and the first check valve 36. Therefore, the first end 53a of the third pipe 53 is connected to the first pipe 51 between the third expansion valve 33 and the first heat storage material 61. Furthermore, the second end 53b of the third pipe 53 is connected to the first pipe 51 between the first heat storage material 61 and the intake port 23a (accumulator 24) of the compressor 23.

Furthermore, the first heat storage material 61 is thermally connected to the fifth region 52a of the second pipe 52 between the outdoor heat exchanger 21 and the first expansion valve 31. For example, the first pipe 51 and the second pipe 52 are spaced apart from each other and pass through the first heat storage material 61. Therefore, the first heat storage material 61 thermally connects the first pipe 51 and the second pipe 52 to each other.

The first heat storage material 61 has a larger heat storage capacity than each of the second region 51b and the fifth region 52a. In addition, the second region 51b and the fifth region 52a are made of metal and are in close contact with the latent heat storage material of the first heat storage material 61. For this reason, heat conduction is likely to occur between the second region 51b and the fifth region 52a and the latent heat storage material of the first heat storage material 61.

The second heat storage material 62 is thermally connected to the third pipe 53. In this embodiment, the second heat storage material 62 is thermally connected to the third pipe 53 between the switching valve 35 and the second check valve 37.

Furthermore, the second heat storage material 62 is thermally connected to the sixth region 52b of the second pipe 52 between the indoor heat exchanger 41 and the second expansion valve 32. For example, the sixth region 52b and the third pipe 53 are spaced apart from each other and pass through the second heat storage material 62. Therefore, the second heat storage material 62 thermally connects the sixth region 52b and the third pipe 53 to each other.

The second heat storage material 62 has a larger heat storage capacity than the third pipe 53 and the sixth region 52b. In addition, the third pipe 53 and the sixth region 52b are made of metal and are in close contact with the latent heat storage material of the second heat storage material 62. For this reason, heat conduction is likely to occur between the third pipe 53 and the sixth region 52b and the latent heat storage material of the second heat storage material 62.

The third heat storage material 63 is thermally connected to the first region 51a of the first pipe 51 between the indoor heat exchanger 41 and the four-way valve 25. Furthermore, the third heat storage material 63 is thermally connected to the second region 51b of the first pipe 51 between the four-way valve 25 and the intake port 23a (accumulator 24) of the compressor 23.

For example, the first region 51a and the second region 51b of the first pipe 51 are spaced apart from each other and pass through the third heat storage material 63. Therefore, the first region 51a and the second region 51b are thermally connected to each other via the third heat storage material 63.

In this embodiment, the third heat storage material 63 is thermally connected to the second region 51b of the first pipe 51 between the four-way valve 25 and the third expansion valve 33. Therefore, the third expansion valve 33 is provided in the first pipe 51 between the third heat storage material 63 and the intake port 23a (accumulator 24) of the compressor 23.

The third heat storage material 63 has a larger amount of heat that can be stored (heat storage capacity) than the first region 51a and the second region 51b. In addition, the first region 51a and the second region 51b are made of metal and are in close contact with the latent heat storage material of the third heat storage material 63. For this reason, heat conduction is likely to occur between the first region 51a and the second region 51b and the latent heat storage material of the third heat storage material 63.

The third heat storage material 63 has a larger latent heat storage material volume and a larger heat storage capacity than the first heat storage material 61 and the second heat storage material 62. The first heat storage material 61 and the second heat storage material 62 have substantially the same latent heat storage material volume and heat storage capacity. The first heat storage material 61 and the second heat storage material 62 may have different latent heat storage material volumes and heat storage capacities.

The first temperature sensor 71 is provided in the fifth region 52a of the second pipe 52 in the vicinity of the first expansion valve 31, at a pre-flow position during cooling operation of the first expansion valve 31, i.e., between the first expansion valve 31 and the first heat storage material 61. The first temperature sensor 71 detects the temperature of the refrigerant flowing through the fifth region 52a in the vicinity of the first expansion valve 31.

The second temperature sensor 72 is provided in the first heat storage material 61. The second temperature sensor 72 detects the intermediate temperature (internal temperature) of the first heat storage material 61. The second temperature sensor 72 is an example of a heat storage material temperature sensor.

The third temperature sensor 73 is provided in the indoor heat exchanger 41 and detects the temperature (intermediate temperature) of the refrigerant flowing through the indoor heat exchanger 41. For example, the third temperature sensor 73 is disposed at a position where the saturation temperature of the refrigerant flowing through the indoor heat exchanger 41 can be obtained. The third temperature sensor 73 may be an indoor unit temperature sensor.

The fourth temperature sensor 74 is provided in the third heat storage material 63 and detects the intermediate temperature (internal temperature) of the third heat storage material 63. The fourth temperature sensor 74 is an example of a heat storage material temperature sensor.

The fifth temperature sensor 75 is provided in the second region 51b of the first pipe 51 near the accumulator 24. The fifth temperature sensor 75 detects the temperature (inlet temperature) of the refrigerant flowing through the second region 51b near the accumulator 24 and into the accumulator 24 (suction port 23a).

The sixth temperature sensor 76 is provided in the second region 51b of the first pipe 51, between the second end 53b of the third pipe 53 and the accumulator 24, and in the vicinity of the second end 53b. The sixth temperature sensor 76 detects the temperature of the refrigerant flowing through the second region 51b in the vicinity of the second end 53b (the temperature of the medium flowing out of the first heat storage material 61 during cooling operation, or the temperature of the medium flowing out of the second heat storage material 62 during heating operation: outlet temperature).

The seventh temperature sensor 77 is provided in the sixth region 52b of the second pipe 52, between the indoor heat exchanger 41 and the second heat storage material 62, and in the vicinity of the indoor heat exchanger 41. The seventh temperature sensor 77 detects the temperature of the medium flowing through the sixth region 52b (the outlet temperature during heating operation).

The eighth temperature sensor 78 is provided in the sixth region 52b of the second pipe 52 between the second heat storage material 62 and the second expansion valve 32 and in the vicinity of the second heat storage material 62. The eighth temperature sensor 78 detects the temperature of the medium flowing through the sixth region 52b (the outlet temperature of the second heat storage material 62 during heating operation).

The ninth temperature sensor 79 is provided in the second heat storage material 62 and detects the intermediate temperature (internal temperature) of the second heat storage material 62. The ninth temperature sensor 79 is an example of a heat storage material temperature sensor.

The tenth temperature sensor 80 is provided in the outdoor heat exchanger 21 and detects the temperature (intermediate temperature, internal temperature) of the refrigerant flowing through the outdoor heat exchanger 21. For example, the tenth temperature sensor 80 is disposed at a position where the saturation temperature of the refrigerant flowing through the outdoor heat exchanger 21 can be obtained.

The control device 14 has, for example, an outdoor control device 14a and an indoor control device 14b. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other by electrical wiring. At least one of the outdoor control device 14a and the indoor control device 14b is, for example, a computer having a control device such as a CPU (Central Processing Unit) or a microcontroller, a ROM (Read Only Memory), a RAM (Random Access Memory), and a storage device such as a flash memory. Note that the control device 14 is not limited to this example. For example, the control device 14 may have only one of the outdoor control device 14a and the indoor control device 14b.

The outdoor control device 14a controls the outdoor blower fan 22, compressor 23, four-way valve 25, first expansion valve 31, second expansion valve 32, third expansion valve 33, and switching valve 35 of the outdoor unit 11. The indoor control device 14b controls the indoor blower fan 42 of the indoor unit 12.

The control device 14 controls the outdoor unit 11 and the indoor unit 12, so that the air conditioning device 10 performs cooling operation, heating operation, dehumidification operation, defrosting operation, cold storage operation, and other operations. The indoor control device 14b may receive signals, for example, from a remote controller, or may receive signals from an information terminal such as a smartphone via a communication device.

Figure 3 is a block diagram showing the functional configuration of the air conditioning device 10 of this embodiment. As shown in Figure 3, the air conditioning device 10 of this embodiment further has an outdoor fan drive circuit 81, an indoor fan drive circuit 82, an inverter circuit 83, a four-way valve drive circuit 84, a first expansion valve drive circuit 85, a second expansion valve drive circuit 86, a third expansion valve drive circuit 87, and a switching valve drive circuit 88.

The outdoor fan drive circuit 81 is a drive circuit for the outdoor blower fan 22. The indoor fan drive circuit 82 is a drive circuit for the indoor blower fan 42. The inverter circuit 83 inverter controls the compressor 23 and changes the operating frequency of the compressor 23. The inverter circuit 83 is, for example, a PAM (Pulse Amplitude Modulation) type inverter circuit. Note that the inverter circuit 83 is not limited to this example.

The four-way valve drive circuit 84 is a drive circuit for the four-way valve 25. The first expansion valve drive circuit 85 is a drive circuit for the first expansion valve 31. The second expansion valve drive circuit 86 is a drive circuit for the second expansion valve 32. The third expansion valve drive circuit 87 is a drive circuit for the third expansion valve 33. The switching valve drive circuit 88 is a drive circuit for the switching valve 35.

The control device 14 is connected to the first to tenth temperature sensors 71-80, the outdoor fan drive circuit 81, the indoor fan drive circuit 82, the inverter circuit 83, the four-way valve drive circuit 84, the first expansion valve drive circuit 85, the second expansion valve drive circuit 86, the third expansion valve drive circuit 87, and the switching valve drive circuit 88. The control device 14 includes a temperature acquisition unit 91, an operation switching unit 92, an outdoor fan control unit 93, an indoor fan control unit 94, a compressor control unit 95, and a valve control unit 96.

The temperature acquisition unit 91 acquires the temperatures (intermediate temperatures) of the outdoor heat exchanger 21 and the indoor heat exchanger 41, the temperature of the refrigerant flowing through each pipe, and the temperatures (intermediate temperatures) of the first heat storage material 61, the second heat storage material 62, and the third heat storage material 63 from the output signals of the first to tenth temperature sensors 71 to 80.

The operation switching unit 92 switches between cooling operation and heating operation in the air conditioning device 10, and between dehumidification operation, defrosting operation, cold storage operation, etc. The operation switching unit 92 may also switch the operation of the air conditioning device 10 to another operating mode.

The outdoor fan control unit 93 controls the outdoor blower fan 22. For example, the outdoor fan control unit 93 controls the outdoor fan drive circuit 81 to control the rotation speed of the motor of the outdoor blower fan 22.

The indoor fan control unit 94 controls the indoor blower fan 42. For example, the indoor fan control unit 94 controls the rotation speed of the motor of the indoor blower fan 42 by controlling the indoor fan drive circuit 82.

The compressor control unit 95 controls the compressor 23. For example, the compressor control unit 95 controls the inverter circuit 83 to control the operating frequency of the compressor 23 through inverter control.

The valve control unit 96 controls the four-way valve 25, the first expansion valve 31, the second expansion valve 32, the third expansion valve 33, and the switching valve 35. The valve control unit 96 drives the actuator of the four-way valve 25 by controlling the four-way valve drive circuit 84, and changes the direction of the refrigerant flowing through the four-way valve 25. The valve control unit 96 changes the opening degree of the first expansion valve 31, the second expansion valve 32, and the third expansion valve 33 by controlling the first expansion valve drive circuit 85, the second expansion valve drive circuit 86, and the third expansion valve drive circuit 87. Furthermore, the valve control unit 96 controls the switching valve drive circuit 88 to change the direction of the refrigerant flowing through the switching valve 35.

Next, the details of the heat exchanger of this embodiment will be described with reference to Figures 4 to 7. Note that in this embodiment, the outdoor heat exchanger 21 on the outdoor unit 11 side and the indoor heat exchanger 41 on the indoor unit 12 side can have the same basic structure. Therefore, the indoor heat exchanger 41 on the indoor unit 12 side will be described as a representative example.

Figure 4 is an exemplary and schematic perspective view showing the overall configuration of the indoor heat exchanger 41 of this embodiment. As shown in Figure 4, the indoor heat exchanger 41 configures a microchannel heat exchanger 43 in which a plurality of thin tubes 43a (thin flow paths) are arranged, for example, in a row in a direction perpendicular to the tube axis direction to form a flat plate-shaped tube group. The microchannel heat exchanger 43 is formed by microfabricating a material with high thermal conductivity, such as aluminum, to form a plurality of thin tubes 43a. Each thin tube 43a has a cross-sectional shape with an equivalent diameter of, for example, 1 mm, and the cross-sectional shape can be, for example, a rectangular shape such as a square shape, a circular shape, an elliptical shape, or the like.

As shown in FIG. 6, the flat plate-shaped microchannel heat exchange body 43 is supported by a first support part 44 (sometimes called a first header; the first support part 44 is omitted in FIG. 4) and a second support part 45 (sometimes called a second header). Fins 46 made of a plurality of thin plates having high thermal conductivity such as aluminum are arranged between the first support part 44 and the second support part 45. As shown in FIG. 4, each fin 46 has a through hole 44a having a shape (size) substantially the same as the outer shape of the microchannel heat exchange body 43, and the microchannel heat exchange body 43 is inserted and fixed. In addition, one end of the common flow paths 48a, 48b for supplying the refrigerant to the indoor heat exchanger 41 is connected to the outside of the first support part 44 (the side opposite to the side where the fins 46 are arranged) as shown in FIG. 6. A through hole (not shown) having substantially the same shape (size) as the common flow passage 48a and the common flow passage 48b is formed in the wall surface of the first support portion 44, and the common flow passage 48a and the common flow passage 48b are connected to each other. The details of the common flow passages 48a and 48b will be described later. One end side of the first support portion 44 is connected to the inside of the first support portion 44 (the side where the fins 46 are arranged). A partition wall 44b is provided for each microchannel heat exchange body 43 inside the first support portion 44, and a common flow passage is formed that connects the corresponding microchannel heat exchange body 43 to the common flow passage 48a or the common flow passage 48b. The fins 46 and the microchannel heat exchange body 43 are fixed to each other using a known connection technique, and are thermally connected to each other. For example, they may be fixed by press fitting, or may be fixed by using a joining technique such as brazing or spot welding. The other end side of the microchannel heat exchange body 43 is connected to and fixed to the outer wall surface of the second support portion 45. The connection structure with the second support part 45 at the other end of the microchannel heat exchange body 43 will be described in detail later.

The thin tubes 43a of the microchannel heat exchanger 43 are filled with a liquid or gaseous refrigerant, or a mixture thereof (a gas-liquid two-phase state) so that it can flow. The refrigerant exchanges heat with the air flowing around the indoor heat exchanger 41 through the fins 46. The heat transfer performance of the indoor heat exchanger 41 can be improved by reducing the diameter of the thin tubes 43a to increase the heat transfer area, reducing the contact heat resistance by brazing the thin tubes 43a and the fins 46, and reducing the ventilation resistance (increasing the air volume) by making the microchannel heat exchanger 43 into a flat tube. In addition, the internal volume of the thin tubes 43a is reduced, which can contribute to reducing the amount of refrigerant charged. The number of microchannel heat exchangers 43 and fins 46 that constitute the indoor heat exchanger 41, and the number of thin tubes 43a formed in the microchannel heat exchanger 43 can be appropriately changed depending on the size (capacity) of the indoor heat exchanger 41.

Figure 5 is an exemplary schematic cross-sectional view showing an air conditioning device 10 (indoor unit 12) equipped with an indoor heat exchanger 41.

As described above, the indoor unit 12 has an indoor heat exchanger 41, an indoor blower fan 42, a filter 16, and, for example, two upper and lower air deflectors 17 (17A, 17B) and multiple left and right air deflectors (not shown) inside the housing 15. The upper and lower air deflectors 17 and the left and right air deflectors may also be referred to as louvers.

As shown in FIG. 5, for the sake of convenience, an X-axis, a Y-axis, and a Z-axis are defined in this specification. The X-axis, the Y-axis, and the Z-axis are mutually perpendicular. The X-axis is set along the width of the indoor unit 12. The Y-axis is set along the depth of the indoor unit 12. The Z-axis is set along the height of the indoor unit 12.

Furthermore, in this specification, the X direction, Y direction, and Z direction are defined. The X direction is a direction along the X axis, and includes the +X direction indicated by the X axis arrow, and the -X direction opposite the X axis arrow. The Y direction is a direction along the Y axis, and includes the +Y direction indicated by the Y axis arrow, and the -Y direction opposite the Y axis arrow. The Z direction is a direction along the Z axis, and includes the +Z direction indicated by the Z axis arrow, and the -Z direction opposite the Z axis arrow. In this embodiment, the +Z direction is the upward direction, and the -Z direction is the downward direction.

The housing 15 is formed in a generally rectangular parallelepiped shape extending in the X direction. The housing 15 may be formed in other shapes. For example, the housing 15 is hung on a wall of a building (indoors). The housing 15 has an upper surface 15a and a lower surface 15b. The upper surface 15a is provided at or near the upper end of the housing 15 and faces generally upward. The lower surface 15b is provided at or near the lower end of the housing 15 and faces generally downward.

The housing 15 is provided with an air passage 18, an intake port 18a, and an exhaust port 18b. The air passage 18 is provided inside the housing 15. The intake port 18a opens, for example, to the upper surface 15a of the housing 15. The exhaust port 18b opens, for example, to the lower surface 15b of the housing 15. The intake port 18a and the exhaust port 18b may open to other parts of the housing 15.

The indoor unit 12 can pass wind through the ventilation passage 18. Wind is a flow of gas such as air. The intake port 18a is provided at one end of the ventilation passage 18 and connects the ventilation passage 18 to the outside of the indoor unit 12. The outlet port 18b is provided at the other end of the ventilation passage 18 and connects the ventilation passage 18 to the outside of the indoor unit 12. In other words, the ventilation passage 18 is provided inside the housing 15, between the intake port 18a and the outlet port 18b.

The indoor heat exchanger 41 is provided in the ventilation duct 18. The indoor heat exchanger 41 exchanges heat with the surrounding gas in the ventilation duct 18. In the case of FIG. 5, for example, three indoor heat exchangers 41 are arranged around the indoor blower fan 42 on the upstream side of the air flowing inside the housing 15 so as to surround the indoor blower fan 42. The indoor heat exchanger 41 has a substantially rectangular shape as shown in FIG. 4, but is arranged at an angle according to the layout relative to the indoor blower fan 42 in order to reduce the size of the indoor unit 12. As a result, the indoor heat exchanger 41 cools the air flowing through the ventilation duct 18 during cooling operation and heats the air flowing through the ventilation duct 18 during heating operation.

The indoor blower fan 42 is provided in the ventilation passage 18. The indoor blower fan 42 rotates around a rotation axis Axf extending in the X direction to blow air from the intake port 18a to the exhaust port 18b in the ventilation passage 18. As a result, the indoor unit 12 draws indoor air into the ventilation passage 18 from the intake port 18a and blows out air (wind) in the ventilation passage 18 from the exhaust port 18b. For this reason, in this specification, the side of the ventilation passage 18 closer to the intake port 18a may be referred to as the upstream side, and the side closer to the exhaust port 18b may be referred to as the downstream side.

The indoor blower fan 42 is located downstream of the indoor heat exchanger 41. Therefore, when the indoor blower fan 42 generates wind, the air (W0) sucked in from the intake port 18a passes through the fins 46 of the indoor heat exchanger 41. As a result, the air flowing through the ventilation passage 18 exchanges heat with the indoor heat exchanger 41.

The filter 16 is provided at the intake port 18a or near the intake port 18a in the ventilation duct 18. The filter 16 is located upstream of the indoor heat exchanger 41. The filter 16 covers the intake port 18a from inside the housing 15. The filter 16, for example, filters the air sucked in from the intake port 18a and captures dust in the air. By configuring the filter 16 with a HEPA filter or the like, it is possible to achieve higher quality air purification processing.

As shown in FIG. 5, the upper and lower air deflectors 17 can be moved between an open position that opens the air outlet 18b and a closed position that closes the air outlet 18b.

The upper and lower air deflectors 17 (17A, 17B) are components that adjust the wind direction of the conditioned air in the vertical direction, and are also called upper and lower louvers. The upper and lower air deflectors 17 are supported by an axis 17a formed in a roughly cylindrical shape extending in the X direction. The axis 17a is supported on the housing 15 so as to be rotatable around a rotation axis AxL extending in the X direction. The upper and lower air deflectors 17A, 17B can each adjust the rotation angle independently, and the direction of the wind (air W1, W2) blown out from the air outlet 18b can be adjusted, for example, between a direction parallel to the +Y direction and a direction parallel to the -Z direction. The left and right air deflectors, not shown, can adjust the angle between the -X direction and the +X direction, and the direction of the wind (air) blown out from the air outlet 18b can be adjusted in the left and right direction of the housing 15 (indoor unit 12). By combining the angle adjustment of the up/down air deflector 17 with the angle adjustment of the left/right air deflector, the direction of the wind (air) blown out from the air outlet 18b can be directed in any direction in the room. In addition, by continuously changing at least one of the angle adjustments of the up/down air deflector 17 and the left/right air deflector, the direction of the wind (air) can be continuously changed.

Next, the detailed structure of the indoor heat exchanger 41 will be described with reference to Figures 6 and 7. Figure 6 is an exemplary and schematic cross-sectional view showing the details of the indoor heat exchanger 41. Also, Figure 7 is an exemplary and schematic cross-sectional view showing the details of the second support portion 45 in Figure 6.

In the case of the indoor heat exchanger 41 of this embodiment, two microchannel heat exchangers 43 are set as one set to constitute the round-trip tube 41A of the indoor heat exchanger 41, and a plurality of round-trip tubes 41A are supported by the first support part 44 and the second support part 45. In the case of FIG. 6, for example, an example in which four sets of round-trip tubes 41A are supported by the first support part 44 and the second support part 45 are shown for the sake of simplicity of illustration. The number of sets of round-trip tubes 41A can be appropriately changed according to the size (heat exchange capacity) of the indoor heat exchanger 41. Note that one microchannel heat exchanger 43 of the round-trip tubes 41A may be referred to as the first tube group 43A, and the other microchannel heat exchanger 43 may be referred to as the second tube group 43B. In addition, the thin tube 43a included in the first tube group 43A may be referred to as the first thin tube 43a1, and the thin tube 43a included in the second tube group 43B may be referred to as the second thin tube 43a2. In addition, the refrigerant flows in the opposite directions in the first thin tube 43a1 and the second thin tube 43a2. For example, when the air conditioning device 10 is in cooling operation, the refrigerant flows in from the first tube group 43A (first thin tube 43a1) (upstream side, lower piping) and flows out from the second tube group 43B (second thin tube 43a2) (downstream side, upper piping). On the other hand, in heating operation, the refrigerant flows in from the second tube group 43B (second thin tube 43a2) (upstream side, upper piping) and flows out from the first tube group 43A (second thin tube 43a2) (downstream side, lower piping).

In addition, in the case of this embodiment, as described above, the bifurcated common flow path 48a is used in front of the first support part 44 to allow the medium to flow (for example, inflow in the case of cooling operation) to the two first pipe groups 43A at the same time, and the bifurcated common flow path 48b is used in front of the first support part 44 to allow the medium to flow (for example, outflow in the case of cooling operation) to the two first pipe groups 43A at the same time. The common flow paths 48a and 48b may allow the refrigerant to flow to three or more first pipe groups 43A (second pipe groups 43B) at the same time. As described above, in the case of heating operation, the flow direction of the medium is reversed. In cooling operation, the medium flowing from the upstream side of the indoor heat exchanger 41 is diverted into a common flow path partitioned by the partition wall 44b of the first support part 44 by the bifurcated common flow path 48a. When the medium flows from the common flow path inside the first support part 44 into the first tube group 43A, it is further divided into each of the first small diameter tubes 43a1. In addition, during cooling operation, the medium that has flowed through the second small diameter tube 43a2 of the second tube group 43B joins at the first support part 44, and then further joins at the common flow path 48b and flows downstream of the indoor heat exchanger 41.

As described above, one side of the microchannel heat exchange body 43 is supported in a state of being connected to the first support part 44. On the other hand, the other side (thin tube 43a) of the microchannel heat exchange body 43 is supported (fixed) in a state of being connected to one side of the second support part 45 as shown in Figs. 6 and 7. As shown in Fig. 7, for example, the connection wall 45a to which the first thin tube 43a1 (first tube group 43A) of the second support part 45 is connected is provided with a first throttle opening 49a having an area smaller than the pipe cross-sectional area of the first thin tube 43a1. Similarly, the connection wall 45b to which the second thin tube 43a2 (second tube group 43B) of the second support part 45 is connected is provided with a second throttle opening 49b having an area smaller than the pipe cross-sectional area of the second thin tube 43a2. The connection between the connecting wall 45a and the first thin tube 43a1 (first tube group 43A) and the connection between the connecting wall 45b and the second thin tube 43a2 (second tube group 43B) are performed using a joining technique such as brazing so that watertightness and airtightness can be maintained. In addition, inside the second support part 45 to which the first thin tube 43a1 (first tube group 43A) and the second thin tube 43a2 (second tube group 43B) are connected, a communication chamber R (see FIG. 6) that communicates the first thin tube 43a1 (first tube group 43A) and the second thin tube 43a2 (second tube group 43B) is provided. A partition wall 50 that divides the communication chamber R into a first communication chamber R1 and a second communication chamber R2 is formed between the connecting wall 45a in which the first throttle opening 49a is formed and the connecting wall 45b in which the second throttle opening 49b is formed. This partition wall 50 has a third throttling opening 50a formed at a position including the center position of the partition wall 50, the area of which is smaller than the flow path cross-sectional area of the communication chamber R. Note that the third throttling opening 50a may be provided in multiple locations as long as it can accelerate and diffuse the flow rate of the refrigerant as it passes through.

The first throttle opening 49a has the function of increasing the flow rate of the medium flowing from the first thin tube 43a1 to the second support portion 45 during cooling operation. The second throttle opening 49b has the function of increasing the flow rate of the medium flowing from the second support portion 45 to the second thin tube 43a2 during cooling operation. The third throttle opening 50a has the function of accelerating the flow rate of the refrigerant and diffusing the passing refrigerant to generate a vortex. The effects of increasing the refrigerant flow and diffusing it will be described in detail later.

In this embodiment, the first communication chamber R1 of the communication chambers R may be provided with an auxiliary partition wall 45c having at least one fourth aperture opening 49c at a position offset from the position where the third aperture opening 50a of the partition wall 50 is formed.

The behavior of the medium when the first tube group 43A and the second tube group 43B are connected to the second support portion 45 of the indoor heat exchanger 41 configured as described above will be explained using Figures 6 and 7.

First, we will explain the flow of refrigerant in the indoor heat exchanger 41 when the air conditioning device 10 is operating in cooling mode.

When the air conditioning device 10 is in cooling operation, the indoor heat exchanger 41 functions as an evaporator. In this case, a low-temperature, low-pressure liquid refrigerant is supplied to the first tube group 43A via the common flow path 48a and the flow path inside the first support part 44. The liquid refrigerant supplied from the common flow path 48a is distributed to the two first tube groups 43A, and further distributed to each first thin tube 43a1 of the first tube group 43A. In this case, by supplying the refrigerant in a nearly liquid state (a state in which almost no gaseous refrigerant is included), the refrigerant can be distributed approximately evenly to each first thin tube 43a1. The control for supplying only liquid refrigerant from the common flow path 48a will be described later.

The liquid refrigerant flowing through each of the first thin tubes 43a1 of the first tube group 43A exchanges heat with the air taken into the housing 15 through the suction port 18a in the indoor unit 12, and a portion of it vaporizes and flows through the first thin tubes 43a1 in a gas-liquid two-phase state.

The indoor heat exchanger 41 may be disposed at an angle as shown in FIG. 5. As a result, the liquid refrigerant separated from the gaseous refrigerant is affected by gravity and tends to accumulate on the lower side of the indoor heat exchanger 41, that is, on the first tube group 43A side, during cooling operation. As a result, the amount of refrigerant circulating in the refrigerant flow path of the air conditioning device 10 may decrease, and the heat exchange efficiency may decrease. In addition, the gasified refrigerant tends to move to the second tube group 43B located above the first tube group 43A. In cooling operation, the contribution rate of the gasified refrigerant to heat exchange decreases. When the liquid refrigerant and the gaseous refrigerant are separated, it becomes difficult to distribute the refrigerant effective for heat exchange evenly to each thin tube 43a, and the heat exchange efficiency (cool air generation efficiency) of the first tube group 43A on the outward path is reduced compared to the heat exchange efficiency of the second tube group 43B on the return path. As a result, the heat exchange efficiency of the indoor heat exchanger 41 as a whole decreases.

The second support portion 45 of the indoor heat exchanger 41 in this embodiment uses the above-mentioned structure to change the flow state of the refrigerant so that more liquid refrigerant can flow toward the second tube group 43B.

As described above, the refrigerant supplied to the first tube group 43A is at low pressure, and in this state, the refrigerant that has evaporated during its passage through the first tube group 43A tends to flow to the second tube group 43B. Therefore, the flow rate of the refrigerant is increased by making the refrigerant in a gas-liquid two-phase state pass through the first throttle opening 49a. As a result, more liquid refrigerant can be made to flow into the first communication chamber R1 along with the gas refrigerant. Furthermore, the refrigerant in the gas-liquid two-phase state with an increased flow rate can be made to collide with the first opposing wall h1 formed in the first communication chamber R1 at a position that blocks the flow direction of the refrigerant, thereby generating turbulence in the refrigerant. As a result, the uniformity of the mixed state of the liquid refrigerant and the gas refrigerant can be improved.

The turbulent refrigerant then passes through the fourth throttle opening 49c formed in the auxiliary partition wall 45c and flows. The turbulence of the refrigerant can be further strengthened by colliding with the second opposing wall h2 formed in the partition wall 50 at a position that blocks the flow direction of the refrigerant. In addition, in the case of FIG. 7, since the fourth throttle opening 49c is formed in the corner of the first communication chamber R1, the refrigerant that collides with the second opposing wall h2 swirls greatly in the first communication chamber R1 that spreads widely on the other side of the fourth throttle opening 49c, and the mixture rate of the liquid refrigerant and the gas refrigerant can be further improved. Although it is necessary to adjust the flow resistance, the fourth throttle opening 49c may be narrowed from the cross-sectional area of the flow path downstream of the fourth throttle opening 49c to accelerate the flow rate of the refrigerant at the fourth throttle opening 49c as well. The auxiliary partition wall 45c may be omitted.

The refrigerant then accelerates again as it passes through the third throttling opening 50a formed in the partition wall 50. In addition, the refrigerant passes through the third throttling opening 50a formed in a position including the center position of the partition wall 50 and is sprayed into the expanded area of the second communication chamber R2, diffusing the turbulent refrigerant. The accelerated refrigerant collides with the third opposing wall h3, which is located in a position that blocks the flow direction, i.e., in a position opposite the third throttling opening 50a, further strengthening the turbulence generated in the refrigerant and further improving the uniformity of the mixture state of the liquid refrigerant and gas refrigerant.

Then, the gas-liquid two-phase refrigerant in a strongly turbulent state passes through the second throttle opening 49b of the common flow path 48b, and the flow speed is accelerated again. As a result, more liquid refrigerant can be supplied to the second thin tube 43a2 of the second tube group 43B. As described above, the refrigerant is distributed from the second communication chamber R2 (second support portion 45) to each second thin tube 43a2 of the second tube group 43B, and the strongly turbulent refrigerant (especially the liquid refrigerant) is distributed in a more uniform state. As a result, it is possible to efficiently flow the liquid refrigerant in the second thin tube 43a2 of the second tube group 43B, and efficient heat exchange can be performed in the second tube group 43B of the return path as well as in the first tube group 43A of the outward path. Furthermore, by increasing the flow rate of the refrigerant through the first throttling opening 49a, the second throttling opening 49b, (the fourth throttling opening 49c), and the third throttling opening 50a, liquid refrigerant can be supplied more efficiently to the first tube group 43A (first thin tube 43a1) on the forward path and the second tube group 43B (second thin tube 43a2) on the return path, so that heat exchange can be performed even more efficiently.

As mentioned above, even if the indoor heat exchanger 41 is placed at an angle, the increased flow rate of the refrigerant and turbulence (vortexing) will send the liquid refrigerant, which tends to accumulate at the lower part of the angle due to the influence of gravity, to the upper side, allowing for more efficient heat exchange.

When the air conditioning device 10 is in heating operation, the indoor heat exchanger 41 functions as a condenser, and the direction of refrigerant flow is opposite to that during cooling operation. The flow of refrigerant during heating will be explained using Figure 7, which is used to explain the flow of refrigerant during cooling operation.

In heating operation, gaseous refrigerant is supplied to the indoor heat exchanger 41, and as it flows through the second thin tube 43a2, it exchanges heat with the air passing through the indoor heat exchanger 41 via the fins 46, dissipating heat and condensing to liquefy. The refrigerant supplied to the second thin tube 43a2 of the indoor heat exchanger 41 is a high-temperature, high-pressure gaseous refrigerant, so the flow rate of gaseous refrigerant increases in the second thin tube 43a2, where the temperature difference between the air and the refrigerant is large, improving condensation performance. On the other hand, the degree of subcooling also increases, and as a result, liquid refrigerant is more likely to accumulate in the second thin tube 43a2 and the communication chamber R. In heating operation, liquid refrigerant does not easily contribute to heat exchange.

On the other hand, in the case of the indoor heat exchanger 41 of this embodiment, when the refrigerant condensed and liquefied in the second thin tube 43a2 flows from the second thin tube 43a2 into the second communication chamber R2 of the communication chamber R together with the gaseous refrigerant, the flow rate is increased at the second throttling opening 49b of the connection wall 45b. In addition, turbulence (vortex) is generated by colliding with the fourth opposing wall h4 that exists in an opposing position that blocks the flow direction of the refrigerant that has passed through the second throttling opening 49b. As a result, the liquefied refrigerant can be mixed with the gaseous refrigerant. Furthermore, the flow rate of the refrigerant that has become turbulent and has become a two-phase gas-liquid state is accelerated again when it passes through the third throttling opening 50a formed in the partition wall 50. In addition, the refrigerant in a turbulent state is diffused by passing through the third throttle opening 50a formed at a position including the center position of the partition wall 50 and being sprayed into the expanded area of the first communication chamber R1, and the accelerated refrigerant collides with the fifth opposing wall h5 located at a position that blocks the flow direction, i.e., the position opposite the third throttle opening 50a. As a result, the turbulence generated in the refrigerant is further strengthened, promoting the mixing state of the liquid refrigerant and the gas refrigerant, and improving uniformity.

Then, the turbulent refrigerant passes through the fourth throttle opening 49c formed in the auxiliary partition wall 45c and flows, further increasing the flow rate. In addition, by colliding with the sixth opposing wall h6 formed at a position that blocks the flow direction of the refrigerant, the turbulence of the refrigerant can be further strengthened and the mixed state of the liquid and gaseous refrigerants can be promoted. In other words, the refrigerant is prevented from existing in a gas-liquid separated state. As a result, the refrigerant is supplied to the first tube group 43A (first thin tube 43a1) in a state where the flow rate of the gas-liquid mixed refrigerant is accelerated. Therefore, during heating operation, the gaseous refrigerant can be efficiently sent to the first thin tube 43a1 on the return path. In addition, the refrigerant whose gas-liquid two-phase state has been promoted by the turbulence is easily distributed evenly to each first thin tube 43a1.

As a result, more gaseous refrigerant can be supplied to the first tube group 43A. As described above, the refrigerant is distributed from the first communication chamber R1 (second support portion 45) to each of the first thin tubes 43a1 of the first tube group 43A, and the strongly turbulent refrigerant (especially the gaseous refrigerant) is distributed in a more uniform state. As a result, the gaseous refrigerant can be efficiently flowed in the first thin tube 43a1 of the first tube group 43A, and efficient heat exchange can be performed in the first tube group 43A on the return path as well as in the second tube group 43B on the outward path. Furthermore, by increasing the flow rate of the refrigerant by the second throttle opening 49b, the third throttle opening 50a, and the fourth throttle opening 49c, the gaseous refrigerant can be efficiently supplied to the second tube group 43B (second thin tube 43a2) on the outward path and the first tube group 43A (first thin tube 43a1) on the return path, so that heat exchange can be performed even more efficiently. In addition, even if the indoor heat exchanger 41 is placed at an angle during heating operation, the refrigerant flow rate increases and becomes turbulent (vortexes), so that liquid refrigerant, which tends to accumulate at the bottom of the slanted position due to the effects of gravity, is mixed with the gaseous refrigerant and sent out, improving the efficiency of refrigerant circulation.

As described above, by using the indoor heat exchanger 41 of this embodiment, more efficient heat exchange can be performed during cooling and heating operations, which contributes to improving the operating efficiency of the air conditioning unit 10, reducing operating costs, and reducing the operating load of the air conditioning unit 10.

In the above example, the heat exchanger configuration of this embodiment that improves the refrigerant flow velocity and generates turbulence (vortexes) is applied to the indoor heat exchanger 41, but it may also be applied to the outdoor heat exchanger 21, and similar effects can be obtained. Furthermore, the air conditioning device 10 may be applied only to the indoor heat exchanger 41 to which the heat exchanger configuration of this embodiment is applied, or only to the outdoor heat exchanger 21. Furthermore, it may be applied to both the indoor heat exchanger 41 and the outdoor heat exchanger 21, and in either case, more efficient heat exchange can be achieved than with conventional heat exchangers.

Next, we will explain the refrigerant circulation control during cooling operation using the flowcharts in Figures 1 and 8.

As mentioned above, in the case of cooling operation, in the indoor heat exchanger 41, the gaseous refrigerant does not contribute to heat exchange for cooling. Therefore, by supplying liquid refrigerant to the indoor heat exchanger 41 of the indoor unit 12, the heat exchange efficiency can be improved. In other words, ideally, it is desirable to provide the indoor heat exchanger 41 with a refrigerant in a completely liquefied state. In addition, if the refrigerant can be discharged from the indoor heat exchanger 41 in liquid form while undergoing heat exchange (if it can be discharged without or with a small amount of gaseous refrigerant), the heat exchange efficiency for cooling can be improved. In addition, if the indoor heat exchanger 41 is placed in the housing 15 in an inclined position as shown in FIG. 5, more liquid refrigerant is supplied to the indoor heat exchanger 41, and further, if the evaporation of the refrigerant can be suppressed inside the indoor heat exchanger 41, the occurrence of poor distribution when the refrigerant is distributed to each thin tube 43a by the second support part 45 can be reduced.

However, when the outdoor temperature in the outdoor environment where the outdoor unit 11 is located is high, the refrigerant does not condense easily in the outdoor heat exchanger 21. As a result, the dryness of the refrigerant flowing through the fifth region 52a increases, and the proportion of gas increases. If the proportion of gaseous refrigerant is high in the fifth region 52a, the amount of refrigerant that can pass through the first expansion valve 31 decreases, and the capacity of the outdoor heat exchanger 21 may decrease.

For example, the cooling capacity (watts) of the air conditioning device 10 when the outdoor temperature is 48°C may be reduced to about half of the cooling capacity (watts) of the air conditioning device 10 when the outdoor temperature is 35°C. In other words, the air conditioning device 10 may have a reduced capacity of the indoor heat exchanger 41 due to an increase in outdoor temperature. Therefore, in the case of the air conditioning device 10 of this embodiment, as shown in FIG. 1, the refrigerant flowing through the fifth region 52a is supercooled by throttling control of the first expansion valve 31. Then, by performing heat exchange between the first heat storage material 61 and the first heat storage material 61 cooled by the lower temperature refrigerant flowing through the second region 51b, the refrigerant is further condensed to promote liquefaction of the gas-liquid two-phase state. Then, by performing gas-liquid separation in the gas-liquid separator 34, more liquid refrigerant is sent to the indoor heat exchanger 41 side. The gas-liquid refrigerant separated in the gas-liquid separator 34 is returned to the compressor 23 via the accumulator 24. The amount of liquid refrigerant supplied from the gas-liquid separator 34 to the indoor heat exchanger 41 is controlled by controlling the second expansion valve 32. As a result, more liquid refrigerant can be supplied to the indoor heat exchanger 41, which operates as an evaporator during cooling operation, allowing for more efficient heat exchange and achieving efficient cooling operation.

Furthermore, the degree of superheat in the indoor heat exchanger 41 is adjusted by throttling control of the second expansion valve 32 and the third expansion valve 33, and the operating frequency of the compressor 23 is controlled so that the refrigerant passes through the indoor heat exchanger 41 as a liquid. As a result, gaseous refrigerant that does not contribute to heat exchange for cooling is suppressed in the indoor heat exchanger 41, allowing more efficient heat exchange.

Figure 8 is an exemplary flowchart showing the flow of control processing during cooling operation of the air conditioning device 10 of this embodiment. For example, when the air conditioning device 10 is started and the cooling operation starts simultaneously, the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 are stopped. In this case, the outdoor fan control unit 93, the indoor fan control unit 94, and the compressor control unit 95 start the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 at the start of the cooling operation.

During cooling operation, the outdoor fan control unit 93 adjusts the rotation speed of the outdoor blower fan 22. The indoor fan control unit 94 adjusts the rotation speed of the indoor blower fan 42. The compressor control unit 95 adjusts the operating frequency of the compressor 23. For example, the indoor fan control unit 94 controls the indoor blower fan 42 between weak wind (low speed) operation and strong wind (high speed) operation in response to the air temperature in the room where the indoor unit 12 is installed or a signal input from a remote controller.

As shown in FIG. 8, when the cooling operation is started, the valve control unit 96 controls the four-way valve drive circuit 84 and the switching valve drive circuit 88 to change the direction of the refrigerant flow through the four-way valve 25 and the switching valve 35 (S100). As a result, the outdoor heat exchanger 21 is connected to the discharge port 23b of the compressor 23, and the indoor heat exchanger 41 is connected to the accumulator 24 (the suction port 23a of the compressor 23). That is, the control device 14 executes the cooling operation to control the four-way valve 25 so that the refrigerant flows from the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21. Furthermore, the third expansion valve 33 is connected to the suction port 23a of the compressor 23 via the first heat storage material 61.

Next, the operation switching unit 92 determines whether or not to end the cooling operation (S102). For example, if the air conditioning device 10 receives a stop signal or a switch signal to another operation from the remote controller, the operation switching unit 92 determines that the cooling operation is to end (Yes in S102) and ends the cooling operation.

If the cooling operation does not end (No in S102), the valve control unit 96 determines whether the difference between the temperature Tc1 and the temperature Tch1 (degree of subcooling) is, for example, about 5°C (first control value) (S104). For example, the temperature acquisition unit 91 acquires the temperature Tc1 at the pre-flow position of the first expansion valve 31 from the first temperature sensor 71. Furthermore, the temperature acquisition unit 91 acquires the intermediate temperature Tch1 of the first heat storage material 61 (first heat transfer unit) from the second temperature sensor 72. Then, the valve control unit 96 controls the first expansion valve drive circuit 85 to control the throttling control of the first expansion valve 31 so that the dryness of the refrigerant flowing into the gas-liquid separator 34 is, for example, 20%, and controls the degree of subcooling to, for example, 5°C, thereby controlling the amount of liquefaction of the refrigerant.

The valve control unit 96 determines whether the degree of subcooling (Tc1-Tch1) is approximately 5°C. For example, the valve control unit 96 determines whether the degree of subcooling (Tc1-Tch1) is within the range of 5±0.5°C for a predetermined period of time. Note that the determination in S104 is not limited to this example.

If the degree of subcooling (Tc1-Tch1) is not approximately 5°C (No in S104), the valve control unit 96 controls the first expansion valve drive circuit 85 to adjust the opening of the first expansion valve 31 (S106). The valve control unit 96 adjusts the opening of the first expansion valve 31 so that the degree of subcooling (Tc1-Tch1) is approximately 5°C. In other words, it controls the amount of liquid refrigerant flowing into the gas-liquid separator 34. If the degree of subcooling (Tc1-Tch1) is approximately 5°C in S104 (Yes in S104), S106 is omitted.

Next, the valve control unit 96 determines whether the difference (degree of superheat) between the temperature Te and the temperature Tch3 is approximately -2°C (second control value) (S108). For example, the temperature acquisition unit 91 detects the intermediate temperature Te of the indoor heat exchanger 41 from the third temperature sensor 73. Furthermore, the temperature acquisition unit 91 acquires the intermediate temperature Tch3 of the third heat storage material 63 from the fourth temperature sensor 74. Then, the valve control unit 96 controls the second expansion valve drive circuit 86 to throttle the second expansion valve 32 so that the temperature difference of the refrigerant between the indoor heat exchanger 41 and the third heat storage material 63 is approximately -2°C, thereby suppressing the gasification of the refrigerant in the indoor heat exchanger 41. In other words, the refrigerant is allowed to flow out of the indoor heat exchanger 41 in a liquid state while heat exchange is being performed.

The valve control unit 96 determines whether the degree of superheat (Te-Tch3) is approximately -2°C. For example, the valve control unit 96 determines whether the degree of superheat (Te-Tch3) is within the range of -2±0.5°C for a predetermined period of time. Note that the determination in S108 is not limited to this example.

If the degree of superheat (Te-Tch3) is not approximately -2°C (No in S108), the valve control unit 96 controls the second expansion valve drive circuit 86 to adjust the opening degree of the second expansion valve 32 (S110). The valve control unit 96 adjusts the opening degree of the second expansion valve 32 so that the degree of superheat (Te-Tch3) is approximately -2°C. If the degree of superheat (Te-Tch3) is approximately -2°C in S108 (Yes in S108), S110 is omitted.

Next, the valve control unit 96 determines whether the difference (degree of superheat) between the temperature Su and the temperature Tk is 2°C (third control value) or less (S112). For example, the temperature acquisition unit 91 acquires the temperature Su of the refrigerant in the vicinity of the accumulator 24 (inlet temperature) from the fifth temperature sensor 75. In other words, the temperature acquisition unit 91 acquires the temperature Su of the refrigerant entering the suction port 23a of the compressor 23 from the fifth temperature sensor 75. Furthermore, the temperature acquisition unit 91 acquires the temperature Tk of the refrigerant in the vicinity of the second end 53b of the third pipe 53 from the sixth temperature sensor 76. In other words, the temperature acquisition unit 91 acquires the temperature Tk (outlet temperature) of the refrigerant exiting the first heat storage material 61 from the sixth temperature sensor 76.

The valve control unit 96 determines whether the degree of superheat (Su-Tk) is 2°C or less. For example, the valve control unit 96 determines whether the degree of superheat (Su-Tk) is 2°C or less for a predetermined period of time. Note that the determination in S112 is not limited to this example.

If the degree of superheat (Su-Tk) is not 2°C or less (No in S112), the valve control unit 96 controls the third expansion valve drive circuit 87 to adjust the opening of the third expansion valve 33 (S114). The valve control unit 96 adjusts the opening of the third expansion valve 33 so that the degree of superheat (Su-Tk) is 2°C or less, and controls so that the refrigerant is reliably vaporized as it passes through the first heat storage material 61 and returned to the compressor 23. If the degree of superheat (Su-Tk) is 2°C or less in S112 (Yes in S112), S114 is omitted.

If the valve control unit 96 adjusts the third expansion valve 33 or the degree of superheat (Su-Tk) is 2°C or less, the process returns to S102 and the operation switching unit 92 again determines whether or not to end the cooling operation. S102 to S114 are repeated until the cooling operation ends.

As shown in FIG. 1, in cooling operation, the high-temperature, high-pressure gaseous refrigerant discharged from the discharge port 23b of the compressor 23 passes through the four-way valve 25 and dissipates heat in the outdoor heat exchanger 21. The medium-temperature, medium-pressure liquid refrigerant condensed in the outdoor heat exchanger 21 is controlled to be subcooled by throttling control of the first expansion valve 31, and undergoes heat exchange again in the first heat storage material 61 to promote liquefaction. Gas-liquid separation is then performed in the gas-liquid separator 34, and the pressure is reduced by the second expansion valve 32.

The low-temperature, low-pressure, fully liquid refrigerant decompressed by the second expansion valve 32 is supplied to the indoor heat exchanger 41, where the refrigerant is distributed to each small-diameter tube 43a in a highly uniform state due to the increase in the flow rate of the refrigerant and turbulence (vortexing), and efficient heat exchange is performed. At this time, the second expansion valve 32 is throttled and the compressor control unit 95 controls the inverter circuit 83 to control the operating frequency of the compressor 23, thereby controlling the degree of superheat and suppressing complete gasification in the indoor heat exchanger 41, and allowing the refrigerant to flow out of the indoor heat exchanger 41 as a liquid. As a result, the retention of liquid refrigerant in the indoor heat exchanger 41 is suppressed, and the circulation efficiency of the refrigerant is improved in the air conditioning device 10 as a whole, which can contribute to improving the heat exchange efficiency and cooling operation performance of the air conditioning device 10 as a whole. The refrigerant that leaves the indoor heat exchanger 41 in a liquid state passes through the four-way valve 25, and then the degree of superheat is controlled by the throttle control of the third expansion valve 33. It is vaporized as it passes through the first heat storage material 61, passes through the accumulator 24, and returns to the intake port 23a of the compressor 23.

In the case of the air conditioning device 10 of this embodiment, in order to liquefy the refrigerant in the first heat storage material 61, it is desirable to further lower the temperature of the refrigerant flowing through the second region 51b to lower the temperature of the first heat storage material 61. In this case, it is possible to carry out a cold storage operation to cool the third heat storage material 63 in advance. The control device 14 of this embodiment can cool the third heat storage material 63 by carrying out the cold storage operation, for example, at night when the air conditioning device 10 is stopped. Note that the time when the cold storage operation is carried out is not limited to this example. It is also possible not to carry out the cold storage operation.

First, the operation switching unit 92 determines whether the conditions for starting the cold storage operation have been met. For example, if the operation switching unit 92 determines that the air conditioning device 10 is stopped and the time is, for example, between 1:00 and 3:00 a.m. (nighttime), it determines that the conditions for starting the cold storage operation have been met.

The start condition of the cold storage operation is not limited to the above example. For example, the operation switching unit 92 may determine the start condition of the cold storage operation based on the outside air temperature. In this case, the temperature acquisition unit 91 may acquire the outside air temperature from a temperature sensor provided near the outdoor heat exchanger 21. The operation switching unit 92 may determine that the start condition of the cold storage operation is achieved when the air conditioning device 10 is stopped and the outside air temperature is below the threshold value for a predetermined time.

The operation switching unit 92 may also determine the start condition based on the presence of a person in the room. In this case, the operation switching unit 92 determines whether or not there is no one in the room based on an output signal from a human presence sensor or the like provided in the housing 15 of the indoor unit 12. If the operation switching unit 92 determines that there is no one in the room for a predetermined period of time, it may determine that the start condition for the cold storage operation has been achieved.

Furthermore, the operation switching unit 92 may determine the start conditions for the cold storage operation based on the required capacity of the air conditioning device 10. In this case, the operation switching unit 92 calculates the required capacity of the air conditioning device 10 (the cooling capacity required of the air conditioning device 10 to make the room temperature the target temperature) based on the difference between the room temperature and the target temperature set by the user, etc. The operation switching unit 92 may determine that the start conditions for the cold storage operation are achieved when the required capacity of the air conditioning device 10 is equal to or less than a predetermined threshold value.

If the conditions for starting the cold storage operation are not met, the operation switching unit 92 waits without starting the cold storage operation. When the conditions for starting the cold storage operation are met, the outdoor fan control unit 93, the indoor fan control unit 94, and the compressor control unit 95 start and adjust the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42.

The valve control unit 96 changes the direction of refrigerant flow in the four-way valve 25 and the switching valve 35, as in the cooling operation. This connects the outdoor heat exchanger 21 to the discharge port 23b of the compressor 23, and connects the indoor heat exchanger 41 to the accumulator 24 (the suction port 23a of the compressor 23). That is, the control device 14 executes a cold storage operation in which the four-way valve 25 is controlled so that the refrigerant flows from the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21. Furthermore, the third expansion valve 33 and the suction port 23a of the compressor 23 are connected via the first heat storage material 61.

The outdoor fan control unit 93 and the compressor control unit 95 control the outdoor blower fan 22 and the compressor 23 in the same manner as in the cooling operation. Note that the control of the outdoor fan control unit 93 and the compressor control unit 95 in the cold storage operation may be different from the control in the cooling operation.

On the other hand, the indoor fan control unit 94 controls the indoor blower fan 42 to operate at a low speed (low wind). That is, the indoor fan control unit 94 rotates the indoor blower fan 42 at the minimum speed during cooling operation. Note that the control of the indoor fan control unit 94 is not limited to this example. For example, the indoor fan control unit 94 may stop the indoor blower fan 42.

Next, the operation switching unit 92 determines whether or not to end the cold storage operation. For example, if the air conditioning device 10 receives a stop signal or a switch signal to another operation from the remote controller, the operation switching unit 92 determines that the cold storage operation is to end, and ends the cold storage operation.

If the cold storage operation does not end, the operation switching unit 92 determines whether a predetermined time has elapsed since the start of the cold storage operation. For example, the operation switching unit 92 ends the cold storage operation when, for example, one hour has elapsed since the start of the cold storage operation.

When a stop signal is input to the air conditioning device 10 from the remote controller, and when a predetermined time has elapsed since the start of cold storage operation, the outdoor fan control unit 93, the indoor fan control unit 94, and the compressor control unit 95 stop the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42.

If a predetermined time has not elapsed since the start of the cold storage operation, the cooling operation control from S104 onwards described in FIG. 8 is executed, and the valve control unit 96 controls the second expansion valve 32 so that the refrigerant leaving the indoor heat exchanger 41 contains more liquid than gas. Furthermore, in the cold storage operation, the indoor fan control unit 94 controls the indoor blower fan 42 so that the refrigerant leaving the indoor heat exchanger 41 contains more liquid than gas.

For example, as described above, the opening degree of the second expansion valve 32 is adjusted so that the degree of superheat (Te-Tch3) is approximately -2°C. As a result, the refrigerant passes through the indoor heat exchanger 41 in a liquid state. Furthermore, as described above, the indoor blower fan 42 operates at a low blower speed. As a result, it becomes difficult for the refrigerant to exchange heat in the indoor heat exchanger 41, and the refrigerant passes through the indoor heat exchanger 41 in a liquid state. Note that by operating the indoor blower fan 42 at a low blower speed, condensation in the indoor heat exchanger 41 is suppressed.

The low-temperature, low-pressure liquid refrigerant coming out of the indoor heat exchanger 41 cools the third heat storage material 63. The low-temperature, low-pressure refrigerant cools the first heat storage material 61 twice: once when it passes through the first region 51a of the first pipe 51 and once when it passes through the second region 51b.

The liquid refrigerant coming out of the third heat storage material 63 is depressurized by the third expansion valve 33. The liquid refrigerant depressurized by the third expansion valve 33 exchanges heat with the first heat storage material 61. In other words, the low-temperature, low-pressure liquid refrigerant flowing through the second region 51b of the first pipe 51 exchanges heat with the medium-temperature, medium-pressure liquid refrigerant flowing through the fifth region 52a of the second pipe 52 via the second heat storage material 62.

In the cold storage operation, the valve control unit 96 controls the third expansion valve 33 so that the refrigerant in the second region 51b that has been transferred heat to the first heat storage material 61 is vaporized. For example, as described above, the opening of the third expansion valve 33 is adjusted so that the superheat degree (Su-Tk) is 2°C or less. As a result, the liquid refrigerant flowing through the second region 51b is warmed and vaporized through the first heat storage material 61 by the medium-temperature and medium-pressure refrigerant flowing through the fifth region 52a. In other words, the third expansion valve 33 adjusts the amount of refrigerant supplied to the first heat storage material 61 to adjust the superheat degree of the refrigerant returning to the suction port 23a of the compressor 23. The refrigerant vaporized by the first heat storage material 61 returns to the suction port 23a of the compressor 23 through the accumulator 24. The refrigerant is vaporized in the first heat storage material 61, preventing it from entering the intake port 23a of the compressor 23 in liquid form.

Meanwhile, the refrigerant flowing through the fifth region 52a is cooled by the low-temperature, low-pressure refrigerant flowing through the second region 51b. In the fifth region 52a, gaseous refrigerant that was not liquefied in the outdoor heat exchanger 21 may flow. In this case, the gaseous refrigerant is cooled by the first heat storage material 61 and liquefied.

If the proportion of gaseous refrigerant is high in the fifth region 52a, the amount of refrigerant that can pass through the first expansion valve 31 may decrease. In this embodiment, the first heat storage material 61 liquefies the refrigerant, thereby increasing the proportion of liquid in the refrigerant that passes through the first expansion valve 31. As a result, the first heat storage material 61 prevents a decrease in the amount of refrigerant supplied to the indoor heat exchanger 41.

As described above, the cold storage operation is performed for, for example, one hour. For example, even in summer, the outside air temperature at night is lower than the outside air temperature during the day. Therefore, the third heat storage material 63 is sufficiently cooled during the night when the cold storage operation is performed.

In cooling operation after cold storage operation, the third heat storage material 63 cools the refrigerant coming out of the indoor heat exchanger 41. The refrigerant cooled by the third heat storage material 63 is depressurized by the third expansion valve 33 and exchanges heat with the first heat storage material 61. In other words, the refrigerant flowing through the second region 51b of the first pipe 51 exchanges heat with the medium-temperature, medium-pressure liquid refrigerant flowing through the fifth region 52a of the second pipe 52 via the first heat storage material 61.

Therefore, in the case of cooling operation, the refrigerant flowing through the second region 51b is warmed and vaporized by the medium-temperature, medium-pressure refrigerant flowing through the fifth region 52a. The refrigerant vaporized in the first heat storage material 61 passes through the accumulator 24 and returns to the intake port 23a of the compressor 23. Because the refrigerant is vaporized in the first heat storage material 61, it is possible to prevent the refrigerant from entering the intake port 23a of the compressor 23 in a liquid state.

The refrigerant flowing through the fifth region 52a is cooled by the refrigerant flowing through the second region 51b. As described above, when the outside air temperature is high, the refrigerant is less likely to condense in the outdoor heat exchanger 21. Therefore, the dryness of the refrigerant flowing through the fifth region 52a increases, and the proportion of gas increases. However, the gaseous refrigerant is cooled and liquefied by the first heat storage material 61. By cooling the refrigerant with the first heat storage material 61, the degree of supercooling of the refrigerant becomes, for example, 5°C or more. As a result, the first heat storage material 61 passes the liquid refrigerant through the first expansion valve 31, and is completely liquefied by gas-liquid separation in the gas-liquid separator 34. In other words, the amount of refrigerant supplied to the indoor heat exchanger 41 is prevented from decreasing.

As described above, the first heat storage material 61 converts the refrigerant supplied to the indoor heat exchanger 41 into a low-temperature, low-pressure liquid, and supplies a sufficient amount of liquid refrigerant to the indoor heat exchanger 41. This allows the air conditioning device 10 to prevent a decrease in the capacity of the indoor heat exchanger 41 even when the outside air temperature is high. In addition, the third heat storage material 63 cools the refrigerant in the second region 51b, allowing the first heat storage material 61 to cool the refrigerant in the fifth region 52a.

In addition, in a typical air conditioning device, when the compressor is stopped, heat may transfer from the outdoor heat exchanger to the indoor heat exchanger, causing the room temperature to rise. However, in the configuration of this embodiment, when the compressor 23 is stopped, the third heat storage material 63 can suppress the transfer of heat from the outdoor heat exchanger 21 to the indoor heat exchanger 41. In other words, even when the compressor 23 is operated intermittently under low load, energy loss can be suppressed, which contributes to energy saving. By providing the third heat storage material 63, as described above, a fully liquefied refrigerant can be efficiently supplied to the indoor heat exchanger 41 during cooling operation, but the third heat storage material 63 may be omitted.

Next, we will explain the refrigerant circulation control during heating operation using the flowcharts in Figures 2 and 9.

In the case of the conventional indoor heat exchanger 41, the degree of supercooling tends to be large. As a result, for example, 20% or more of the indoor heat exchanger 41 may contain a liquid refrigerant with a low temperature. In this case, the temperature of the hot air blown out from the indoor unit 12 is, for example, about 43°C. In addition, when the indoor heat exchanger 41 is in a two-phase gas-liquid state of liquid and gas, as shown in FIG. 5, if the indoor heat exchanger 41 is placed in an inclined position, the liquid refrigerant may accumulate at the bottom due to the influence of gravity, and the gas refrigerant may exist in a separated state at the top, resulting in uneven distribution of the refrigerant to each thin tube 43a and a decrease in the circulation efficiency of the refrigerant. Therefore, in the case of the indoor heat exchanger 41 of this embodiment, as described above, the above-mentioned problems are improved by increasing the flow rate of the refrigerant and generating turbulence (vortex). Furthermore, the above-mentioned problems are further improved by controlling the indoor heat exchanger 41 to prevent the refrigerant from liquefying as much as possible and to flow out of the indoor heat exchanger 41 as a gas.

In this embodiment, the indoor heat exchanger 41 allows gaseous refrigerant to flow out from the indoor heat exchanger 41 by controlling the opening degree of the first expansion valve 31 and the operating frequency of the compressor 23. For example, the frequency of the compressor 23 is controlled to prevent liquefaction in the indoor heat exchanger 41 (to prevent a large degree of subcooling), and the second expansion valve 32 is controlled to control the degree of subcooling and the amount of refrigerant flowing to the gas-liquid separator 34. In addition, the gaseous refrigerant flowing out from the indoor heat exchanger 41 is liquefied on the outdoor unit 11 side and provided to the outdoor heat exchanger 21. Furthermore, the first expansion valve 31 and the third expansion valve 33 are controlled to control the degree of superheat of the refrigerant, so that the liquefied refrigerant does not exchange heat with the outside air in the outdoor heat exchanger 21 too much. In this case, the liquid refrigerant flowing out of the outdoor heat exchanger 21 is gasified by heat exchange in the third heat storage material 63 and the second heat storage material 62, and is returned to the compressor 23 via the accumulator 24. In other words, the heat exchange in the outdoor heat exchanger 21 is suppressed to reduce the operating load, and frost formation on the outdoor heat exchanger 21 is suppressed to contribute to energy saving during heating operation and reduction of defrosting operation. Note that if the third heat storage material 63 is omitted, the liquid refrigerant flowing out of the outdoor heat exchanger 21 is gasified by heat exchange in the second heat storage material 62.

Figure 9 is an exemplary flowchart showing the flow of heating operation control of an air conditioning device 10 equipped with an indoor heat exchanger 41. For example, when the air conditioning device 10 is started and the heating operation starts simultaneously, the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 are stopped. In this case, the outdoor fan control unit 93, the indoor fan control unit 94, and the compressor control unit 95 start the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 when the heating operation starts.

9, when the heating operation is started, the valve control unit 96 controls the four-way valve drive circuit 84 and the switching valve drive circuit 88 to change the direction of the refrigerant flow to the four-way valve 25 and the switching valve 35 (S200). As a result, the indoor heat exchanger 41 is connected to the discharge port 23b of the compressor 23, and the outdoor heat exchanger 21 is connected to the accumulator 24 (the suction port 23a of the compressor 23). That is, the control device 14 executes the heating operation to control the four-way valve 25 so that the refrigerant flows from the discharge port 23b of the compressor 23 to the indoor heat exchanger 41. Furthermore, the third expansion valve 33 is connected to the suction port 23a of the compressor 23 via the third piping 53 and the second heat storage material 62.

Next, the operation switching unit 92 determines whether or not to end the heating operation (S202). For example, if the air conditioning device 10 receives a stop signal or a switch signal to another operation from the remote controller, the operation switching unit 92 determines that the heating operation is to end (Yes in S202) and ends the heating operation.

If the heating operation does not end (No in S202), the compressor control unit 95 controls the operating frequency of the compressor 23 via the inverter circuit 83 so that the difference between temperature T3 and temperature Te becomes, for example, -2°C (fourth control value) (S204). For example, the temperature acquisition unit 91 acquires the outlet temperature T3 of the indoor heat exchanger 41 from the seventh temperature sensor 77. Furthermore, the temperature acquisition unit 91 acquires the intermediate temperature Te of the indoor heat exchanger 41 from the third temperature sensor 73.

The valve control unit 96 determines whether the temperature difference (T3-Te) between the outlet temperature and the intermediate temperature of the indoor heat exchanger 41 is, for example, approximately -2°C (S204). For example, the compressor control unit 95 determines whether the temperature difference (T3-Te) between the outlet temperature and the intermediate temperature is within the range of -2±0.5°C over a predetermined period of time. Note that the determination in S204 is not limited to this example.

If the temperature difference (T3-Te) between the outlet temperature and the intermediate temperature is not approximately -2°C (No in S204), the compressor control unit 95 controls the inverter circuit 83 to adjust the operating frequency of the compressor 23 (S206). The compressor control unit 95 adjusts the operating frequency of the compressor 23 so that the temperature difference (T3-Te) between the outlet temperature and the intermediate temperature of the indoor heat exchanger 41 is approximately -2°C, thereby preventing the refrigerant from liquefying (supercooling) in the indoor heat exchanger 41 and allowing the refrigerant to be discharged from the indoor heat exchanger 41 in a gaseous state. In other words, as described above, uneven distribution of the refrigerant to each small diameter tube 43a inside the indoor heat exchanger 41 can be suppressed, and the temperature of the hot air blown out from the indoor unit 12 is suppressed from decreasing due to the liquefied refrigerant. If the temperature difference (T3-Te) between the outlet temperature and the intermediate temperature is approximately -2°C (Yes in S204), S206 is omitted.

Next, the valve control unit 96 determines whether the difference (degree of subcooling) between the temperature Tc2 and the temperature Tch2 is, for example, about 5°C (fifth control value) (S208). For example, the temperature acquisition unit 91 acquires the outlet temperature Tc2 of the second heat storage material 62 from the eighth temperature sensor 78. Furthermore, the temperature acquisition unit 91 acquires the intermediate temperature Tch2 of the second heat storage material 62 from the ninth temperature sensor 79.

The valve control unit 96 determines whether the degree of subcooling (Tc2-Tch2) is approximately 5°C. For example, the valve control unit 96 determines whether the degree of subcooling (Tc2-Tch2) is within the range of 5±0.5°C for a predetermined period of time. Note that the determination in S208 is not limited to this example.

If the degree of subcooling (Tc2-Tch2) is not about 5°C (S208noNo), the valve control unit 96 controls the second expansion valve drive circuit 86 to adjust the opening of the second expansion valve 32 (S210). The valve control unit 96 adjusts the opening of the second expansion valve 32 so that the degree of subcooling (Tc2-Tch2) is about 5°C, thereby setting the dryness of the refrigerant flowing to the gas-liquid separator 34 to, for example, 20% and controlling the amount of refrigerant flowing to the second heat storage material 62 and the gas-liquid separator 34. In other words, the gaseous refrigerant flowing through the second heat storage material 62 is cooled and liquefied by heat exchange and supplied to the gas-liquid separator 34. If the degree of subcooling (Tc2-Tch2) is about 5°C in S208 (S208Yes), S210 is omitted.

Next, the valve control unit 96 determines whether the difference (degree of superheat) between the temperature Tch3 and the temperature Te1 is, for example, 1°C or less (sixth control value) (S212). For example, the temperature acquisition unit 91 acquires the intermediate temperature Tch3 of the third heat storage material 63 from the fourth temperature sensor 74. Furthermore, the temperature acquisition unit 91 acquires the intermediate temperature Te of the outdoor heat exchanger 21 from the tenth temperature sensor 80.

The valve control unit 96 determines whether the degree of superheat (Tch3-Te) is equal to or less than approximately 1°C. For example, the valve control unit 96 determines whether the degree of superheat (Tch3-Te) is within the range of 1±0.5°C for a predetermined period of time. Note that the determination in S212 is not limited to this example.

If the degree of superheat (Tch3-Te) is not approximately 1°C or less (No in S212), the valve control unit 96 controls the first expansion valve drive circuit 85 to adjust the opening degree of the first expansion valve 31 (S214). The valve control unit 96 adjusts the opening degree of the first expansion valve 31 so that the degree of superheat (Tch3-Te) is approximately 1°C or less, thereby preventing the refrigerant from evaporating too much inside the outdoor heat exchanger 21. In other words, separation of gas and liquid inside the outdoor heat exchanger 21 is suppressed. As a result, uneven distribution of the refrigerant to each thin tube 43a inside the outdoor heat exchanger 21 can be suppressed, and by reducing the degree of superheat (Tch3-Te) to approximately 1°C or less, the formation of frost on the surface of the outdoor heat exchanger 21 is suppressed. In other words, the frequency of defrosting operation of the air conditioning device 10 is reduced, contributing to improving the heating operation efficiency of the air conditioning device 10. If the degree of superheat (Tch3-Te) is less than or equal to approximately 1°C in S212 (Yes in S212), S214 is omitted.

Next, the valve control unit 96 determines whether the difference (degree of superheat) between the temperature Su and the temperature Tk is, for example, 2°C or less (seventh control value) (S216). For example, the temperature acquisition unit 91 acquires the inlet temperature Su of the suction port 23a (accumulator 24) of the compressor 23 from the fifth temperature sensor 75. Furthermore, the temperature acquisition unit 91 acquires the temperature Tk of the refrigerant near the second end 53b of the third pipe 53 from the sixth temperature sensor 76. In other words, the temperature acquisition unit 91 acquires the temperature Tk (outlet temperature) of the refrigerant exiting the second heat storage material 62 from the sixth temperature sensor 76.

The valve control unit 96 determines whether the degree of superheat (Su-Tk) is equal to or less than approximately 2°C. For example, the valve control unit 96 determines whether the degree of superheat (Su-Tk) is within the range of 2±0.5°C for a predetermined period of time. Note that the determination in S216 is not limited to this example.

If the degree of superheat (Su-Tk) is not about 2°C or less (No in S216), the valve control unit 96 controls the third expansion valve drive circuit 87 to adjust the opening degree of the third expansion valve 33 (S218). The valve control unit 96 adjusts the amount of refrigerant vaporized in the third heat storage material 63 and the second heat storage material 62 by adjusting the opening degree of the third expansion valve 33 so that the degree of superheat (Su-Tk) is about 2°C or less. As a result, as described above, the amount of refrigerant that has been reduced in the outdoor heat exchanger 21 is vaporized by heat exchange when passing through the third heat storage material 63 and the second heat storage material 62 (evaporation of liquid refrigerant), and the gas refrigerant can be efficiently returned to the compressor 23. If the degree of superheat (Tch3-Te) is about 2°C or less in S216 (Yes in S212), S214 is omitted.

If the valve control unit 96 adjusts the third expansion valve 33 or the degree of superheat (Su-Tk) is 2°C or less, the process returns to S202, and the operation switching unit 92 again determines whether or not to end the heating operation. S202 to S218 are repeated until the heating operation ends.

As shown in FIG. 2, in heating operation, the high-temperature, high-pressure gaseous refrigerant discharged from the discharge port 23b of the compressor 23 passes through the four-way valve 25 and superheats the third heat storage material 63. The high-temperature, high-pressure gaseous refrigerant that has passed through the third heat storage material 63 dissipates heat in the indoor heat exchanger 41.

As mentioned above, gaseous refrigerant has a higher heat exchange efficiency in the indoor heat exchanger 41 than liquid refrigerant. Therefore, the first expansion valve 31 improves the heat exchange efficiency in the indoor heat exchanger 41 by keeping the refrigerant passing through the indoor heat exchanger 41 in a gaseous state. In this way, by suppressing the presence of refrigerant in a gas-liquid two-phase state inside the indoor heat exchanger 41, uneven distribution of the refrigerant in each small diameter tube 43a of the indoor heat exchanger 41 can be suppressed, and a decrease in the heat exchange efficiency of the refrigerant can be suppressed. In addition, by suppressing liquefaction of the refrigerant in the indoor heat exchanger 41, a decrease in the temperature of the hot air blown out from the indoor unit 12 can be suppressed, and the heating operation efficiency can be improved. In addition, accumulation of liquid refrigerant in the indoor heat exchanger 41 can be reduced, which contributes to improving the circulation efficiency of the refrigerant.

The medium-temperature, medium-pressure gaseous refrigerant that has passed through the indoor heat exchanger 41 exchanges heat with the second heat storage material 62. In other words, the medium-temperature, medium-pressure gaseous refrigerant flowing through the sixth region 52b of the second pipe 52 exchanges heat with the low-temperature, low-pressure refrigerant flowing through the third pipe 53 via the second heat storage material 62.

The gaseous refrigerant flowing through the sixth region 52b is cooled and liquefied by the low-temperature, low-pressure refrigerant flowing through the third pipe 53. That is, the second heat storage material 62 compensates for the degree of subcooling of the refrigerant flowing through the sixth region 52b. The refrigerant liquefied by the second heat storage material 62 is depressurized by the second expansion valve 32. The refrigerant is liquefied by the second heat storage material 62, and is further separated into gas and liquid by the gas-liquid separator 34. The medium flow rate is adjusted by the first expansion valve 31, and the refrigerant is supplied to the outdoor heat exchanger 21.

The low-temperature, low-pressure liquid refrigerant is controlled by the first expansion valve 31 to suppress heat absorption in the outdoor heat exchanger 21. By suppressing the evaporation of the refrigerant in the outdoor heat exchanger 21, the operating load on the outdoor heat exchanger 21 is reduced and the generation of frost is suppressed. As a result, this contributes to reducing the need for defrosting operations.

The liquid refrigerant, whose evaporation in the outdoor heat exchanger 21 is suppressed, flows through the second region 51b of the first pipe 51, and is heated as it passes through the third heat storage material 63, and is also heated by the refrigerant flowing through the sixth region 52b via the second heat storage material 62. That is, the third heat storage material 63 and the second heat storage material 62 compensate for the degree of superheat of the refrigerant returning to the compressor 23. As a result, the gaseous refrigerant can be efficiently returned to the compressor 23 while reducing the operating load of the outdoor heat exchanger 21.

In addition, by preventing the refrigerant from being present in a gas-liquid two-phase state inside the indoor heat exchanger 41, uneven distribution of the refrigerant in each small-diameter tube 43a of the indoor heat exchanger 41 can be prevented, and a decrease in the heat exchange efficiency of the refrigerant can be prevented. In addition, by preventing the refrigerant from liquefying in the indoor heat exchanger 41, a decrease in the temperature of the warm air blown out from the indoor unit 12 can be prevented, improving the heating operation efficiency. In addition, accumulation of liquid refrigerant in the indoor heat exchanger 41 can be reduced, contributing to improved refrigerant circulation efficiency.

In addition, the gaseous refrigerant flowing out from the indoor heat exchanger 41 is controlled by controlling the throttle amount of the second expansion valve 32, and becomes liquid refrigerant when passing through the second heat storage material 62, and is separated into gas and liquid in the gas-liquid separator 34, and only the liquid refrigerant is supplied to the outdoor heat exchanger 21. At this time, the throttle control of the first expansion valve 31 and the third expansion valve 33 is performed to control the superheat degree of the refrigerant so that the liquefied refrigerant does not exchange heat with the outside air in the outdoor heat exchanger 21 too much. The liquid refrigerant flowing out from the outdoor heat exchanger 21 is gasified by heat exchange with the third heat storage material 63 and the second heat storage material 62, and is returned to the compressor 23 via the accumulator 24. In other words, the heat exchange in the outdoor heat exchanger 21 is suppressed to reduce the operating load, and frost is suppressed on the outdoor heat exchanger 21, contributing to energy saving during heating operation and reduction in defrosting operation. In addition, the third heat storage material 63 and the second heat storage material 62 increase the temperature and pressure of the refrigerant returned to the compressor 23. As a result, an increase in the workload of the compressor 23 can be suppressed. This allows the air conditioning device 10 of this embodiment to suppress an increase in the power consumption of the air conditioning device 10 caused by a decrease in the outside air temperature, thereby enabling energy savings.

In the above explanation, an example was shown in which the indoor heat exchanger 41 as described in Figures 5 to 7 is applied to an air conditioning device 10 that includes a gas-liquid separator 34, a first heat storage material 61, a second heat storage material 62, a third heat storage material 63, etc. in the outdoor unit 11. However, the configuration of the air conditioning device 10 other than the heat exchanger is not important. For example, it may be applied to a general air conditioning device that does not include a gas-liquid separator 34, a first heat storage material 61, a second heat storage material 62, a third heat storage material 63, etc.

Figure 10 is an exemplary schematic diagram showing a refrigerant system diagram of a general air conditioning device 10A that does not include the gas-liquid separator 34, the first heat storage material 61, the second heat storage material 62, the third heat storage material 63, etc., shown in Figure 1.

As shown in FIG. 10, the air conditioning device 10A has an outdoor unit 11A, an indoor unit 12A, a first pipe 51 and a second pipe 52 as refrigerant pipes, a control device (not shown), etc.

The outdoor unit 11A has an outdoor heat exchanger 21M, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, an expansion valve 31, etc. The indoor unit 12A has an indoor heat exchanger 41M and an indoor blower fan 42.

In cooling operation, the refrigerant comes out of the discharge port 23b of the compressor 23 in a high-temperature, high-pressure gaseous state and flows through the first pipe 51 to the outdoor heat exchanger 21M, which functions as a condenser. The refrigerant then dissipates heat and is liquefied in the outdoor heat exchanger 21M, is depressurized in the first expansion valve 31, becomes a low-temperature, low-pressure liquid refrigerant, and flows through the second pipe 52 to the indoor heat exchanger 41M. The low-temperature, low-pressure liquid refrigerant absorbs heat in the indoor heat exchanger 41M, which functions as an evaporator. As a result, cold air is blown out from the indoor unit 12A. The refrigerant gasified in the indoor heat exchanger 41M returns to the compressor 23 from the suction port 23a via the four-way valve 25 and the accumulator 24, completing one cycle during cooling operation. In heating operation, the refrigerant flows through the first pipe 51 and the second pipe 52 in the opposite direction to that in cooling operation, the outdoor heat exchanger 21M functions as an evaporator, the indoor heat exchanger 41M functions as a condenser, and warm air is blown out from the indoor unit 12A.

Even in a typical air conditioning unit 10A as shown in FIG. 10, the same effect as described above can be obtained by employing a microchannel heat exchanger (indoor heat exchanger 41) having a first throttle opening 49a, a second throttle opening 49b, a third throttle opening 50a, etc. in the second support portion 45 as shown in FIG. 5 to FIG. 7. In other words, compared to the case of employing a conventional microchannel heat exchanger, it is possible to contribute to suppressing uneven distribution of the refrigerant in the small diameter tubes 43a, improving the circulation efficiency of the refrigerant, and improving the heat exchange efficiency.

The heat exchanger of the air conditioning unit 10 according to the embodiment described above includes a first tube group 43A consisting of a plurality of first thin tubes 43a1 through which a refrigerant can flow in one direction, a second tube group 43B consisting of second thin tubes 43a2 through which a refrigerant can flow in a direction different from that of the first thin tubes 43a1, a second support part 45 having a communication chamber R that connects the first thin tubes 43a1 and the second thin tube 43a2, a first throttling opening 49a having an area smaller than the cross-sectional area of the first thin tube 43a1 and provided in the connection wall 45a to which the first thin tube 43a1 of the second support part 45 is connected, and a second throttling opening 49b having an area smaller than the cross-sectional area of the second thin tube 43a2 and provided in the connection wall 45b to which the second thin tube 43a2 of the second support part 45 is connected. With this configuration, for example, the flow rate of the medium flowing into the communication chamber R is increased, turbulence (vortex) is easily formed inside the communication chamber R, and the liquid refrigerant and the gaseous refrigerant are less likely to separate inside the heat exchanger, improving uniformity when distributed to the first thin tube 43a1 and the second thin tube 43a2. As a result, it can contribute to improving the heat exchange efficiency of the heat exchanger. In addition, accumulation of liquid refrigerant inside the heat exchanger is suppressed, improving the circulation efficiency of the refrigerant, and realizing efficient operation of the air conditioning device 10.

The communication chamber R may also be provided with a partition wall 50 having a third throttling opening 50a between the first throttling opening 49a and the second throttling opening 49b, the third throttling opening 50a having an area smaller than the cross-sectional area of the flow passage of the communication chamber R. With this configuration, for example, it is possible to generate strong turbulence (vortex) in the refrigerant within the communication chamber R, and the mixability (homogenization) of the liquid refrigerant and the gaseous refrigerant can be further promoted.

The third throttling opening 50a may be formed at a position including the center (in other words, the center) of the partition wall 50, for example, approximately at the center of the partition wall 50. With this configuration, for example, the refrigerant that has passed through the third throttling opening 50a is more likely to diffuse in the communication chamber R after passing through. As a result, the refrigerant with more uniform gas-liquid mixability can be more easily distributed to the downstream thin tube 43a, further improving the heat exchange efficiency.

The communication chamber R may also include an auxiliary partition wall 45c having at least one fourth throttle opening 49c at a position offset from the position where the third throttle opening 50a of the partition wall 50 is formed. With this configuration, for example, it is possible to increase the flow rate of the refrigerant in the communication chamber R and improve turbulence (vortexing).

The communication chamber R may also include opposing walls (first opposing wall h1, second opposing wall h2, third opposing wall h3, fourth opposing wall h4, fifth opposing wall h5) that block the flow direction of the refrigerant passing through the first throttling opening 49a, the second throttling opening 49b, and the third throttling opening 50a. With this configuration, for example, it is possible to easily generate turbulence (vortexes) in the refrigerant whose flow rate has increased through the first throttling opening 49a, the second throttling opening 49b, the third throttling opening 50a, the fourth throttling opening 49c, etc.

The heat exchanger described above may be provided in at least one of the outdoor unit 11 and the indoor unit 12. This configuration makes it possible to improve the heat exchange efficiency of the refrigerant, the circulation efficiency of the refrigerant, and the like in the air conditioning device 10, for example, and contributes to improving the operating efficiency of the air conditioning device 10.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

10...air conditioning device, 11...outdoor unit, 12...indoor unit, 13...refrigerant piping, 14...control device, 21...outdoor heat exchanger, 22...outdoor blower fan, 23...compressor, 24...accumulator, 25...four-way valve, 31...first expansion valve, 32...second expansion valve, 33...third expansion valve, 34...gas-liquid separator, 35...switching valve, 41...indoor heat exchanger, 41A...reciprocating tube, 43...microchannel heat exchanger, 43A...first tube group, 43B...second tube group, 43a...thin tube, 43a1...first thin tube, 43a2...second thin tube, 45...second support portion, 45a, 45b...connecting wall, 45c...auxiliary partition wall, 49a...first throttle opening, 49b...second throttle 49c...fourth throttle opening, 50...partition wall, 50a...third throttle opening, 61...first heat storage material, 62...second heat storage material, 63...third heat storage material, 71...first temperature sensor, 72...second temperature sensor, 73...third temperature sensor, 74...fourth temperature sensor, 75...fifth temperature sensor, 76...sixth temperature sensor, 77...seventh temperature sensor, 78...eighth temperature sensor, 79...ninth temperature sensor, 80...tenth temperature sensor, R...communication chamber, R1...first communication chamber, R2...second communication chamber, h1...first opposing wall, h2...second opposing wall, h3...third opposing wall, h4...fourth opposing wall, h5...fifth opposing wall, h6...sixth opposing wall.

Claims (6)

a first tube group including a plurality of first small diameter tubes through which a refrigerant can flow in one direction;
a second tube group including second thin tubes through which the refrigerant can flow in a direction different from that of the first thin tubes;
a support portion having a communication chamber that communicates the first thin tube and the second thin tube;
a first throttle opening portion having an area smaller than a pipe cross-sectional area of the first thin tube, the first throttle opening portion being provided in a first connection wall to which the first thin tube is connected of the support portion;
a second throttle opening portion having an area smaller than a pipe cross-sectional area of the second thin tube, the second throttle opening portion being provided in a second connection wall of the support portion to which the second thin tube is connected;
Equipped with
the first throttle opening is opened in the first connecting wall at a lower area side of a pipe cross section in a direction perpendicular to the flow direction of the refrigerant in the first thin tube, and the second throttle opening is opened in the second connecting wall at a lower area side of a pipe cross section in a direction perpendicular to the flow direction of the refrigerant in the second thin tube.
Heat exchanger. The heat exchanger according to claim 1, wherein the communication chamber is provided with a partition wall having a third throttling opening between the first throttling opening and the second throttling opening, the third throttling opening having an area smaller than the cross-sectional area of the communication chamber. The heat exchanger according to claim 2, wherein the third throttle opening is formed at a position including the center of the partition wall. The heat exchanger according to claim 2 or 3, wherein the communication chamber is provided with an auxiliary partition wall having at least one fourth throttle opening at a position offset from the position where the third throttle opening is formed in the partition wall. The heat exchanger according to any one of claims 2 to 4, wherein the communication chamber is provided with an opposing wall portion that blocks the flow direction of the refrigerant passing through the first throttling opening, the second throttling opening, and the third throttling opening. An air conditioner having a heat exchanger according to any one of claims 1 to 5 in at least one of an indoor unit and an outdoor unit.

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