Air conditioner

Abstract

To provide an air conditioner which hardly receives an influence of the outside air, and which can avoid deterioration in operation efficiency and deterioration in operation capability, while achieving downsizing of an outdoor unit.SOLUTION: An outdoor heat exchanger of an air conditioner is provided in an outdoor unit. An indoor heat exchanger is provided in an indoor unit. First piping connects the indoor heat exchanger and the outdoor heat exchanger, and a refrigerant flows in it. Second piping connects the outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows in it. A compressor is provided in the first piping, and includes a suction port for sucking the refrigerant, and a discharge port for discharging the refrigerant. A four-way valve is provided in the first piping, and can change the direction in which the refrigerant flows. An expansion valve is provided in the second piping. A first heat adjustment mechanism is arranged on the flow upstream side of the air which is made to pass the outdoor heat exchanger when allowing the outdoor heat exchanger to exchange heat, and can cool / heat the air going toward the outdoor heat exchanger.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to an air conditioner.

Background Art

[0002] An air conditioner such as an air conditioner adjusts the indoor temperature by condensing and evaporating the refrigerant in the refrigeration cycle. In the cooling operation, the refrigerant condenses in the outdoor heat exchanger (condenser) and evaporates in the indoor heat exchanger (evaporator) to supply cold air into the room. In the heating operation, the refrigerant evaporates in the outdoor heat exchanger (evaporator) and condenses in the indoor heat exchanger (condenser) to supply warm air into the room.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the outdoor unit in the air conditioner as described above changes the state of the refrigerant by exchanging heat with air (outside air). Therefore, the air conditioner has a problem that it is affected by the outside air temperature and causes a decrease in operating efficiency and a decrease in operating capacity. In addition, there is a problem that it is necessary to increase the size of the outdoor unit or increase the circulation amount of the refrigerant in order to avoid a decrease in operating efficiency and operating capacity.

[0005] An example of the problem to be solved by the present invention is to provide an air conditioner that is hardly affected by the outside air temperature, realizes downsizing of the outdoor unit, and can avoid a decrease in operating efficiency and a decrease in operating capacity.

Means for Solving the Problems

[0006] An air conditioner according to an embodiment of the present invention includes an outdoor heat exchanger, an indoor heat exchanger, a first pipe, a second pipe, a compressor, a four-way valve, an expansion valve, and a first heat adjustment mechanism. The outdoor heat exchanger is provided in an outdoor unit. The indoor heat exchanger is provided in an indoor unit. The first pipe connects the indoor heat exchanger and the outdoor heat exchanger, and refrigerant flows therethrough. The second pipe connects the outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows therethrough. The compressor is provided in the first pipe and has a suction port for sucking the refrigerant and a discharge port for discharging the refrigerant. The four-way valve is provided in the first pipe and can change the direction in which the refrigerant flows. The expansion valve is provided in the second pipe. The first heat adjustment mechanism is disposed on the upstream side of the air flow passing through the outdoor heat exchanger when causing heat exchange in the outdoor heat exchanger and can cool or heat the air flowing toward the outdoor heat exchanger.

[0007] Further, the first heat adjustment mechanism of the air conditioner may include, for example, a heat adjustment plate in which a through hole through which the air can pass is formed, and a thermoelectric element for the plate that changes the temperature of the heat adjustment plate.

[0008] Further, the air conditioner may include, for example, a first on-off valve disposed in the first pipe between the four-way valve and the indoor heat exchanger, the first pipe between the four-way valve and the suction port of the compressor, a third pipe connecting the second pipe between the expansion valve and the outdoor heat exchanger for the front drive, a first three-way valve disposed at the connection position between the second pipe and the third pipe and switching between a first connection state connecting the indoor heat exchanger and the outdoor heat exchanger and a second connection state connecting the indoor heat exchanger and the third pipe, a fourth pipe connecting the first pipe between the first on-off valve and the indoor heat exchanger and the second pipe between the first three-way valve and the outdoor heat exchanger, a second on-off valve provided in the fourth pipe, a fifth pipe connecting the fourth pipe between the connection position of the second on-off valve and the second pipe and the third pipe, and a second three-way valve provided at the connection position between the fourth pipe and the fifth pipe and switching between a third connection state connecting the first pipe and the second pipe and a fourth connection state connecting the first pipe and the fifth pipe, and a second heat adjustment mechanism provided across the third pipe and the fourth pipe and capable of heating the refrigerant flowing through the third pipe or the refrigerant flowing through the fourth pipe.

[0009] Further, the air conditioner may include, for example, a third heat adjustment mechanism provided in the first pipe between the four-way valve and the outdoor heat exchanger and capable of cooling or heating the refrigerant flowing through the first pipe.

[0010] Further, the third heat adjustment mechanism of the air conditioner may include, for example, a heat storage material in contact with the first pipe and a thermoelectric element for the heat storage material that transfers heat to the heat storage material.

[0011] According to the above air conditioner, for example, an air conditioner that is less affected by the outside air temperature, realizes miniaturization of the outdoor unit, and can avoid a decrease in operating efficiency and a decrease in operating capacity can be obtained.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, some embodiments will be described with reference to FIGS. 1 to 8. In this specification, the components according to the embodiments and the descriptions of the components may be described in a plurality of expressions. The components and their descriptions are examples and are not limited by the expressions in this specification. The components may be specified by different names from those in this specification. Also, the components may be described by expressions different from those in this specification.

[0014] FIG. 1 is an exemplary and schematic diagram showing a refrigerant system diagram of an air conditioner 10 according to an embodiment. The air conditioner 10 is, for example, a household 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. The air conditioner 10 according to the embodiment can continuously operate at a low load without stopping even after the room temperature reaches the set temperature, and has a function that enables dehumidification and defrosting during heating even during low load operation.

[0015] As shown in FIG. 1, the air conditioner 10 includes an outdoor unit 11, an indoor unit 12, a refrigerant pipe 13, and a control device 14. The outdoor unit 11 is disposed outdoors, for example. The indoor unit 12 is disposed indoors, for example.

[0016] The air conditioner 10 includes a refrigeration cycle in which the outdoor unit 11 and the indoor unit 12 are connected by the refrigerant pipe 13. The refrigerant flows through the refrigerant pipe 13 between the outdoor unit 11 and the indoor unit 12. Further, the outdoor unit 11 and the indoor unit 12 are electrically connected to each other by, for example, electrical wiring.

[0017] The outdoor unit 11 includes an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, a first on-off valve 26, a second on-off valve 27, an expansion valve 28, a first three-way valve 29 (switching valve), a second three-way valve 30 (switching valve), a first heat adjustment mechanism 31, a second heat adjustment mechanism 32, a third heat adjustment mechanism 33, a receiver tank 34, and the like. The indoor unit 12 includes an indoor heat exchanger 41 and an indoor blower fan 42.

[0018] The refrigerant pipe 13 is a pipe through which a refrigerant made of a metal such as copper or aluminum flows, for example. The refrigerant pipe 13 includes a first pipe 51, a second pipe 52, a third pipe 53, a fourth pipe 54, a fifth pipe 55, and the like.

[0019] The first pipe 51 connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The compressor 23, the accumulator 24, the four-way valve 25, the first on-off valve 26, and the third heat adjustment mechanism 33 are provided in the first pipe 51. The first pipe 51 has a first region 51a, a second region 51b, a third region 51c, a fourth region 51d, a fifth region 51e, and a sixth region 51f. The first region 51a is a pipe region connecting the indoor heat exchanger 41 and the first on-off valve 26. The second region 51b is a pipe region connecting the first on-off valve 26 and the four-way valve 25. The third region 51c is a pipe region connecting the four-way valve 25 and the accumulator 24. The fourth region 51d is a pipe region connecting the discharge port 23b of the compressor 23 and the four-way valve 25. The fifth region 51e is a pipe region connecting the four-way valve 25 and the third heat adjustment mechanism 33. The sixth region 51f is a pipe region connecting the third heat adjustment mechanism 33 and the outdoor heat exchanger 21. During the cooling operation, the high-pressure and high-temperature gaseous refrigerant discharged from the compressor 23 is supplied to the outdoor heat exchanger 21 side. Also, during the heating operation, the high-pressure and high-temperature gaseous refrigerant discharged from the compressor 23 is supplied to the indoor heat exchanger 41 side.

[0020] The second pipe 52 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. The expansion valve 28, the receiver tank 34, and the first three-way valve 29 are provided in the second pipe 52. The second pipe 52 has a seventh region 52a, an eighth region 52b, a ninth region 52c, and a tenth region 52d. The seventh region 52a is a pipe region connecting the indoor heat exchanger 41 and the expansion valve 28. The eighth region 52b is a pipe region connecting the expansion valve 28 and the first opening 34a of the receiver tank 34. The receiver tank 34 is a tank that temporarily stores the refrigerant circulating in the refrigerant pipe 13, and includes a first opening 34a and a second opening 34b through which the refrigerant can flow in and out. The ninth region 52c is a pipe region connecting the second opening 34b of the receiver tank 34 and the first three-way valve 29. The tenth region 52d is a pipe region connecting the first three-way valve 29 and the outdoor heat exchanger 21. During the cooling operation, the refrigerant flowing out from the outdoor heat exchanger 21 is supplied to the indoor heat exchanger 41 side. Also, during the heating operation, the refrigerant flowing out from the indoor heat exchanger 41 is supplied to the outdoor heat exchanger 21 side.

[0021] The third pipe 53 connects the first pipe 51 (the third region 51c) between the four-way valve 25 and the suction port 23a (accumulator 24) of the compressor 23 and the second pipe 52 (the ninth region 52c) between the expansion valve 28 and the outdoor heat exchanger 21 via the first three-way valve 29. The second heat adjustment mechanism 32 is provided in the third pipe 53. The third pipe 53 has an eleventh region 53a and a twelfth region 53b. The eleventh region 53a is a pipe region connecting the third region 51c of the first pipe 51 and the opening 32a at one end of one flow path passing through the second heat adjustment mechanism 32. The twelfth region 53b is a pipe region connecting the opening 32b at the other end of one flow path passing through the second heat adjustment mechanism 32 and the first three-way valve 29.

[0022] The fourth pipe 54 connects the first pipe 51 (the first region 51a) between the first on-off valve 26 and the indoor heat exchanger 41 and the second pipe (the tenth region 52d) between the first three-way valve 29 and the outdoor heat exchanger 21. The second heat adjustment mechanism 32, the second on-off valve 27 (flow control valve), and the second three-way valve 30 are provided in the fourth pipe 54. The fourth pipe 54 has a thirteenth region 54a, a fourteenth region 54b, a fifteenth region 54c, and a sixteenth region 54d. The thirteenth region 54a is a pipe region connecting the first region 51a of the first pipe 51 and the opening 32c at one end of the other flow path passing through the second heat adjustment mechanism 32. The fourteenth region 54b is a pipe region connecting the opening 32d at the other end of the other flow path passing through the second heat adjustment mechanism 32 and the second on-off valve 27. The fifteenth region 54c is a pipe region connecting the second on-off valve 27 and the second three-way valve 30. Therefore, the second heat adjustment mechanism 32 allows the third pipe 53 and the fourth pipe 54 to penetrate each other, enabling heat exchange between the refrigerant flowing through the third pipe 53 and the refrigerant flowing through the fourth pipe 54. The sixteenth region 54d is a pipe region connecting the second three-way valve 30 and the tenth region 52d of the second pipe 52.

[0023] The fifth pipe 55 is connected to the fourth pipe 54 (the fifteenth region 54c) between the connection position of the second on-off valve 27 and the second pipe 52 (the tenth region 52d), the third pipe 53 (the twelfth region 53b), and through the second three-way valve 30.

[0024] During normal load (non-low load) cooling operation, no refrigerant flow occurs in the third pipe 53, the fourth pipe 54, and the fifth pipe 55.

[0025] The outdoor heat exchanger 21 of the outdoor unit 11 absorbs heat from the refrigerant as an evaporator or releases heat from the refrigerant as a condenser according to the direction of refrigerant flow. The outdoor blower fan 22 blows air to the outdoor heat exchanger 21 to promote heat exchange between the refrigerant and the air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an air flow that exchanges heat with the outdoor heat exchanger 21.

[0026] The air conditioner 10 of the present embodiment includes a first heat adjustment mechanism 31 on the upstream side of the flow of air (outdoor air) that passes through the outdoor heat exchanger 21 when heat exchange is performed with the outdoor heat exchanger 21. The first heat adjustment mechanism 31 adjusts the temperature of the air by cooling or heating the passing air. Details of the first heat adjustment mechanism 31 will be described later.

[0027] The compressor 23 has a suction port 23a and a discharge port 23b. The compressor 23 sucks refrigerant from the suction port 23a and discharges the compressed refrigerant from the discharge port 23b. Thereby, the compressor 23 compresses the refrigerant in the refrigeration cycle and causes the refrigerant to circulate.

[0028] The accumulator 24 is connected to the suction port 23a of the compressor 23. When the refrigerant contains liquid refrigerant, the accumulator 24 separates the gaseous refrigerant and the liquid refrigerant. Thereby, the compressor 23 can suck the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can be configured integrally with the compressor 23 to serve as the suction port of the compressor 23.

[0029] The four-way valve 25 is provided in the first pipe 51 and is connected to the first on-off valve 26, the accumulator 24, the compressor 23, and the third heat adjustment mechanism 33. The four-way valve 25 switches the flow paths connected to the first on-off valve 26, the accumulator 24, the compressor 23, and the third heat adjustment mechanism 33 during cooling operation and heating operation, and changes the direction in which the refrigerant flows.

[0030] The first on-off valve 26 closes during low-load cooling operation to prevent the refrigerant flowing out of the indoor heat exchanger 41 from directly returning to the accumulator 24 via the four-way valve 25. The first on-off valve 26 is controlled to be open except during low-load cooling operation. Details of the operation of the first on-off valve 26 in each operating state will be described later.

[0031] The second on-off valve 27 also functions as a flow control valve that controls the flow rate of the refrigerant passing through it in addition to being fully open and fully closed. The second on-off valve 27 stops the flow of the refrigerant in the fourth pipe 54 by being fully closed. Further, the second on-off valve 27 adjusts the flow rate of the refrigerant in the fourth pipe 54 by opening valve control. Details of the operation of the second on-off valve 27 in each operating state will be described later.

[0032] The expansion valve 28 is, for example, an electromagnetic expansion valve. Note that the expansion valve 28 may be another type of expansion valve. The expansion valve 28 controls its opening degree to adjust the amount of refrigerant passing through it to determine the expansion amount of the refrigerant and to adjust the refrigerant temperature.

[0033] The first three-way valve 29 and the second three-way valve 30 may be other types of solenoid valves or the like as long as they can switch the flow path. The first three-way valve 29 is disposed at the connection position between the second pipe 52 and the third pipe 53. Then, the first three-way valve 29 switches between a first connection state in which the indoor heat exchanger 41 and the outdoor heat exchanger 21 are connected and a second connection state in which the indoor heat exchanger 41 and the third pipe 53 are connected. The second three-way valve 30 is provided at the connection position between the fourth pipe 54 and the fifth pipe 55. Then, the second three-way valve 30 switches between a third connection state in which the first pipe 51 and the second pipe 52 are connected and a fourth connection state in which the first pipe 51 and the fifth pipe 55 are connected.

[0034] As described above, the air conditioner 10 of the present embodiment includes a first heat adjustment mechanism 31 on the upstream side of the flow of air (outside air) that passes through the outdoor heat exchanger 21 when heat exchange is performed with the outdoor heat exchanger 21.

[0035] FIG. 2 is an exemplary and schematic explanatory diagram showing the structure of the first heat adjustment mechanism 31. FIG. 2 shows a sectional view and a plan view of the first heat adjustment mechanism 31 arranged side by side. As shown in FIG. 2, the first heat adjustment mechanism 31 is arranged, for example, on the opposite side of the outdoor blower fan 22 across the outdoor heat exchanger 21, and enables adjustment of the temperature of the air F before the air F moved by the outdoor blower fan 22 passes through the outdoor heat exchanger 21. The first heat adjustment mechanism 31 is composed of a heat adjustment plate 31P and a first thermoelectric element 31H (which may also be referred to as a thermoelectric element for the plate). The heat adjustment plate 31P is, for example, a plate-like member formed of a material with high thermal conductivity and can be formed of, for example, metal. The heat adjustment plate 31P has a plurality of through holes 31Pa formed on its surface and allows the passage of the air F. Further, the heat adjustment plate 31P is provided with a first thermoelectric element 31H that changes the temperature of the heat adjustment plate 31P. In the case of the example shown in FIG. 2, the first thermoelectric element 31H is arranged in contact with the thickness portion of the heat adjustment plate 31P so as to surround the periphery of the heat adjustment plate 31P. Although FIG. 2 shows that the first thermoelectric element 31H is arranged on the left and right surfaces and the upper surface of the heat adjustment plate 31P, the arrangement position can be appropriately selected as long as the temperature of the heat adjustment plate 31P can be changed sufficiently. For example, it may be attached to the lower surface and arranged around the entire circumference. Also, it may be arranged in a part of the periphery, or may be arranged in a part of the surface where the through holes 31Pa are formed. Also, in the case of FIG. 2, three first thermoelectric elements 31H are arranged, but it may be composed of a continuous single one, or conversely, the first thermoelectric element 31H may be divided and arranged on each surface. Note that the shape, size, etc. of the heat adjustment plate 31P can be appropriately changed as long as the temperature of the air F passing through the through holes 31Pa can be adjusted and the same effect can be obtained.

[0036] The first thermoelectric element 31H is an energy conversion element (Peltier element) that utilizes the interaction between heat and electricity. The first thermoelectric element 31H is, for example, a sheet-like element formed by joining two different types of metals or semiconductors at two points. When an electric current is passed through this element, heat is also transported when the current flows from one contact to the other, causing one contact to be cooled and the other to be heated. As a result, in the first thermoelectric element 31H, when the surface in contact with the heat adjustment plate 31P is cooled, the heat adjustment plate 31P is cooled, and the temperature of the air F passing through the through-hole 31Pa can be lowered. Also, when a current in the reverse direction is passed through the first thermoelectric element 31H and the surface in contact with the heat adjustment plate 31P is heated, the heat adjustment plate 31P is heated, and the temperature of the air F passing through the through-hole 31Pa can be increased. That is, the temperature of the air F supplied to the outdoor heat exchanger 21 can be controlled. For example, when the outdoor heat exchanger 21 functions as a condenser during the cooling operation, air cooled by the first heat adjustment mechanism 31 is supplied to the outdoor heat exchanger 21. Also, when the outdoor heat exchanger 21 functions as an evaporator during the heating operation, air heated by the first heat adjustment mechanism 31 is supplied to the outdoor heat exchanger 21. As a result, it becomes difficult to be affected by the outside air temperature, and it becomes possible to increase the heat exchange efficiency in the outdoor heat exchanger 21. Therefore, it becomes possible to reduce the capacity of the outdoor heat exchanger 21, and for example, it can also contribute to the miniaturization of the outdoor heat exchanger 21 and thus the miniaturization of the outdoor unit 11.

[0037] The second heat adjustment mechanism 32 is provided across the third pipe 53 and the fourth pipe 54. FIG. 3 is an exemplary and schematic explanatory diagram showing the structure of the second heat adjustment mechanism 32. Note that FIG. 3 shows a sectional view and a plan view of the second heat adjustment mechanism 32 arranged side by side. The second heat adjustment mechanism 32 is composed of a first heat storage material 32K and a second thermoelectric element 32H. The first heat storage material 32K is arranged so as to surround the third pipe 53 and the fourth pipe 54. The first heat storage material 32K can be formed, for example, by filling a latent heat storage material in a block-shaped container. The latent heat storage material is, for example, calcium chloride. The first heat storage material 32K may have other latent heat storage materials. The third pipe 53 and the fourth pipe 54 passing through the first heat storage material 32K may be arranged so that heat exchange can occur between the heat stored in the first heat storage material 32K and the refrigerant flowing through the third pipe 53 and the fourth pipe 54. The third pipe 53 and the fourth pipe 54 may penetrate the first heat storage material 32K linearly, for example, but as shown in FIG. 3, by arranging them in a meandering shape or a spiral shape, it is desirable to increase the contact area with the first heat storage material 32K to improve the heat exchange efficiency. Further, for example, on the outer peripheral surface of the first heat storage material 32K, a second thermoelectric element 32H for heating the first heat storage material 32K is wound. The second thermoelectric element 32H is, for example, a Peltier element and can be temperature-adjusted by electrical control. Note that the second heat adjustment mechanism 32 is mainly used to heat the passing refrigerant. Therefore, a heater element that can be temperature-adjusted by electrical control similar to the second thermoelectric element 32H may be used. When using a heater element, it may be embedded inside the first heat storage material 32K.

[0038] As shown in FIG. 3, an opening 32a to which an eleventh region 53a of a third pipe 53, which is one of the flow paths passing through the second heat adjustment mechanism 32, is connected is formed on one end side of the first heat storage material 32K, and an opening 32b to which a twelfth region 53b of the third pipe 53 is connected is formed on the other end side. Similarly, an opening 32c to which a thirteenth region 54a of a fourth pipe 54, which is the other flow path passing through the second heat adjustment mechanism 32, is connected is formed on one end side of the first heat storage material 32K, and an opening 32d to which a fourteenth region 54b of the fourth pipe 54 is connected is formed on the other end side. Note that the first heat storage material 32K may store heat using the heat of the refrigerant when, for example, a high-temperature refrigerant flows through the thirteenth region 54a of the fourth pipe 54 and passes through the first heat storage material 32K, or when the high-temperature refrigerant stays within the first heat storage material 32K.

[0039] The third heat adjustment mechanism 33 is provided in the first pipe 51 between the four-way valve 25 and the outdoor heat exchanger 21. FIG. 4 is an exemplary and schematic explanatory diagram showing the structure of the third heat adjustment mechanism 33. Note that FIG. 4 shows a sectional view and a plan view of the third heat adjustment mechanism 33 side by side. Similar to the second heat adjustment mechanism 32, the third heat adjustment mechanism 33 is composed of a second heat storage material 33K and a third thermoelectric element 33H (which may also be referred to as a thermoelectric element for heat storage material). The second heat storage material 33K is arranged so as to surround the first pipe 51. The second heat storage material 33K can be formed, for example, by filling a latent heat storage material into a block-shaped container. The latent heat storage material is, for example, calcium chloride. The second heat storage material 33K may have other latent heat storage materials. The first pipe 51 passing through the second heat storage material 33K may be arranged so that heat exchange can occur between the heat stored in the second heat storage material 33K and the refrigerant flowing through the first pipe 51. The first pipe 51 may penetrate the second heat storage material 33K linearly, for example, but as shown in FIG. 4, it is desirable to arrange it in a meandering shape or a spiral shape to increase the contact area with the second heat storage material 33K and improve the heat exchange efficiency. Further, for example, on the outer peripheral surface of the second heat storage material 33K, a third thermoelectric element 33H for cooling or heating the second heat storage material 33K is wound. The third thermoelectric element 33H is, for example, a Peltier element and can be temperature-adjusted by electrical control.

[0040] As shown in FIG. 4, an opening 33a is formed at one end of the second heat storage material 33K, to which a fifth region 51e of a first pipe 51, which is a flow path passing through the third heat adjustment mechanism 33, is connected. An opening 33b to which a sixth region 51f of the first pipe 51 is connected is formed at the other end. As will be described later, during the cooling operation, when the refrigerant flows from the compressor 23 side to the outdoor heat exchanger 21 side with respect to the third heat adjustment mechanism 33, the refrigerant is preliminarily cooled by the second heat storage material 33K cooled by the third thermoelectric element 33H, assisting the heat exchange in the outdoor heat exchanger 21. Conversely, during the heating operation, when the refrigerant flows from the outdoor heat exchanger 21 side to the compressor 23 side with respect to the third heat adjustment mechanism 33, the refrigerant is heated by the second heat storage material 33K heated by the third thermoelectric element 33H, promoting gasification.

[0041] The receiver tank 34 includes a first opening 34a and a second opening 34b, and is an example of a gas-liquid separator having a simple structure configured as a storage tank capable of temporarily storing the refrigerant. During the cooling operation, the refrigerant flows into the receiver tank 34 from the second opening 34b and flows out from the first opening 34a. Also, during the heating operation, the refrigerant flows into the receiver tank 34 from the first opening 34a and flows out from the second opening 34b.

[0042] The control device 14 controls the outdoor air supply fan 22, the indoor air supply fan 42, the compressor 23, each valve, each thermoelectric element, etc. provided in the outdoor unit 11 and the indoor unit 12, and performs cooling operation, low-load cooling operation, heating operation, low-load heating operation, dehumidifying operation, defrosting operation, and other operation controls. The control device 14 is composed of, for example, an outdoor control device 14a provided in the outdoor unit 11, an indoor control device 14b provided in the indoor unit 12, etc. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other to send and receive control signals, and cooperate to control the outdoor unit 11 and the indoor unit 12. The indoor control device 14b provided in the indoor unit 12 may be controlled by receiving a signal from a remote controller operated by a user, or may be controlled by receiving a signal from an information terminal such as a smartphone through a communication device. Note that the outdoor control device 14a and the indoor control device 14b may be collectively regarded as one control device 14. In this case, the control device 14 may be provided in the outdoor unit 11 or the indoor unit 12, but can be provided in the indoor unit 12, for example.

[0043] The control device 14 is 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.

[0044] FIG. 5 is an exemplary and schematic block diagram showing the control device 14 of the air conditioner 10 of the present embodiment and the configuration controlled by the control device 14. As shown in FIG. 5, the air conditioner 10 of the present embodiment includes an outdoor fan drive circuit 71, an indoor fan drive circuit 72, an inverter circuit 73, a four-way valve drive circuit 74, a first on-off valve drive circuit 75, a second on-off valve drive circuit 76, an expansion valve drive circuit 77, a first three-way valve drive circuit 78, a second three-way valve drive circuit 79, a first thermoelectric element drive circuit 80, a second thermoelectric element drive circuit 81, a third thermoelectric element drive circuit 82, etc.

[0045] The outdoor fan drive circuit 71 is the drive circuit for the outdoor air supply fan 22. The indoor fan drive circuit 72 is the drive circuit for the indoor air supply fan 42. The inverter circuit 73 performs inverter control on the compressor 23 and changes the frequency of the compressor 23. The inverter circuit 73 is, for example, an inverter circuit of the PAM (Pulse Amplitude Modulation) method. Note that the inverter circuit 73 is not limited to this example.

[0046] The four-way valve drive circuit 74 is the drive circuit for the four-way valve 25. The first on-off valve drive circuit 75 is the drive circuit for the first on-off valve 26. The second on-off valve drive circuit 76 is the drive circuit for the second on-off valve 27. The expansion valve drive circuit 77 is the drive circuit for the expansion valve 28. The first three-way valve drive circuit 78 is the drive circuit for the first three-way valve 29. The second three-way valve drive circuit 79 is the drive circuit for the second three-way valve 30. The first thermoelectric element drive circuit 80 is the drive circuit for the first thermoelectric element 31H. The second thermoelectric element drive circuit 81 is the drive circuit for the second thermoelectric element 32H. The third thermoelectric element drive circuit 82 is the drive circuit for the third thermoelectric element 33H.

[0047] The control device 14 is connected to temperature sensors T (T1 to T4, Su) provided in the refrigerant pipe 13, the indoor heat exchanger 41, the outdoor heat exchanger 21, the second heat adjustment mechanism 32, etc., the outdoor fan drive circuit 71, the indoor fan drive circuit 72, the inverter circuit 73, the four-way valve drive circuit 74, the first on-off valve drive circuit 75, the second on-off valve drive circuit 76, the expansion valve drive circuit 77, the first three-way valve drive circuit 78, the second three-way valve drive circuit 79, the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82. 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, a valve control unit 96, and a thermoelectric element control unit 97.

[0048] The temperature acquisition unit 91 measures the temperatures of respective parts within the refrigeration cycle using each temperature sensor T, and reflects them in the control of each drive circuit. For example, the temperature sensor T1 is disposed near the indoor heat exchanger 41 in the first region 51a of the first pipe 51 to detect the temperature of the refrigerant. The temperature sensor T2 is disposed near the indoor heat exchanger 41 in the seventh region 52a of the second pipe 52 to detect the temperature of the refrigerant. The temperature sensor T3 is disposed on the outdoor heat exchanger 21 to detect the temperature of the outdoor heat exchanger 21. The temperature sensor T4 is disposed on the first heat adjustment mechanism 31 to detect the temperature of the heat adjustment plate 31P. The temperature sensor T5 is disposed on the second thermoelectric element 32H to detect the temperature of the first heat storage material 32K. The temperature sensor T6 is disposed on the third thermoelectric element 33H to detect the temperature of the second heat storage material 33K. The temperature sensor Su is disposed near the accumulator 24 in the third region 51c of the first pipe 51 to detect the temperature of the refrigerant. Although not shown in the figure, a plurality of temperature sensors are disposed within the refrigeration cycle, and their detection results are reflected in each control.

[0049] The operation switching unit 92 switches between the cooling operation, low-load cooling operation, heating operation, low-load heating operation, dehumidifying operation, defrosting operation, and other operations in the air conditioner 10.

[0050] The outdoor fan control unit 93 controls the outdoor blower fan 22. For example, the outdoor fan control unit 93 controls the rotation speed of the motor of the outdoor blower fan 22 by controlling the outdoor fan drive circuit 71.

[0051] 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 72, and adjusts the amount (air volume, wind strength) of cold air or warm air blown into the room.

[0052] The compressor control unit 95 controls the compressor 23. For example, the compressor control unit 95 controls the frequency (operating frequency) of the compressor 23 by controlling the inverter circuit 73 through inverter control, and adjusts the compression capacity (normal load operation, low-load operation) of the compressor 23.

[0053] The valve control unit 96 controls the four-way valve 25, the first on-off valve 26, the second on-off valve 27, the expansion valve 28, the first three-way valve 29, and the second three-way valve 30. By controlling the four-way valve drive circuit 74, the valve control unit 96 drives the actuator of the four-way valve 25 to change the direction in which the refrigerant flows through the four-way valve 25. By controlling the first on-off valve drive circuit 75, the valve control unit 96 drives the actuator of the first on-off valve 26 to switch between the fully closed state and the fully open state of the first on-off valve 26. By controlling the second on-off valve drive circuit 76, the valve control unit 96 drives the actuator of the second on-off valve 27 to adjust the fully closed state, the fully open state, and the amount of refrigerant flowing through the second on-off valve 27. By controlling the expansion valve drive circuit 77, the valve control unit 96 changes the opening degree of the expansion valve 28 to adjust the refrigerant flow rate and the expansion amount and to adjust the refrigerant temperature. By controlling the first three-way valve drive circuit 78 and the second three-way valve drive circuit 79, the valve control unit 96 drives the actuators of the first three-way valve 29 and the second three-way valve 30 to change the direction in which the refrigerant flows. The first three-way valve 29 switches between the first connection state and the second connection state, and the second three-way valve 30 switches between the third connection state and the fourth connection state. The valve control unit 96 controls the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82 to change the amount of current supplied and the direction of flow, thereby adjusting heat absorption (cooling) and heat generation (heating) in the first thermoelectric element 31H, the second thermoelectric element 32H, and the third thermoelectric element 33H. In this embodiment, the second thermoelectric element 32H is used only for heating.

[0054] An example of each operating state of the air conditioner 10 configured as described above will be described with reference to FIGS. 1 and 6 to 8.

[0055] First, with reference to FIG. 1, the cooling operation of the air conditioner 10 in the normal load state will be described together with the refrigerant flow pattern.

[0056] In the case of normal-load cooling operation, when the air conditioner 10 starts up and the cooling operation starts simultaneously, the outdoor air supply fan 22, the compressor 23, and the indoor air supply 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 up the outdoor air supply fan 22, the indoor air supply fan 42, and the compressor 23 at the start of the cooling operation.

[0057] During normal-load cooling operation, the outdoor fan control unit 93 adjusts the rotational speed of the outdoor air supply fan 22. The indoor fan control unit 94 adjusts the rotational speed of the indoor air supply fan 42. For example, the indoor fan control unit 94 controls the indoor air supply fan 42 between weak-wind (low-speed) operation and strong-wind (high-speed) operation according to the temperature inside the room where the indoor unit 12 is installed or a signal input from the remote controller, and the compressor control unit 95 adjusts the frequency of the compressor 23.

[0058] When the normal-load cooling operation starts, the valve control unit 96 controls the four-way valve drive circuit 74, the first three-way valve drive circuit 78, and the second three-way valve drive circuit 79 to change the direction in which the refrigerant flows in the four-way valve 25, the first three-way valve 29, and the second three-way valve 30 for normal-load cooling. Also, the valve control unit 96 controls the first on-off valve drive circuit 75, the second on-off valve drive circuit 76, and the expansion valve drive circuit 77 to change the on-off state of the first on-off valve 26, the second on-off valve 27, and the expansion valve 28 for normal-load cooling. Further, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82 to control the control states of the first thermoelectric element 31H, the second thermoelectric element 32H, and the third thermoelectric element 33H for normal-load cooling.

[0059] Specifically, the four-way valve 25 connects the fourth region 51d and the fifth region 51e of the first pipe 51, and connects the discharge port 23b of the compressor 23 and the opening 33a of the third heat adjustment mechanism 33. As a result, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23 is supplied to the outdoor heat exchanger 21 side. Further, the valve control unit 96 controls the first on-off valve drive circuit 75 to fully open the first on-off valve 26. Also, the valve control unit 96 controls the second on-off valve drive circuit 76 to fully close the second on-off valve 27. The valve control unit 96 controls the first three-way valve drive circuit 78 to switch the first three-way valve 29, connect the tenth region 52d and the ninth region 52c of the second pipe 52 to form a first connection state, and connect the outdoor heat exchanger 21 and the receiver tank 34. Then, the valve control unit 96 controls the expansion valve drive circuit 77 to control the opening degree of the expansion valve 28 and adjust the expansion state of the liquid refrigerant supplied from the receiver tank 34.

[0060] At this time, the thermoelectric element control unit 97 controls the third thermoelectric element drive circuit 82 to put the third thermoelectric element 33H in an endothermic (cooling) state and cool the second heat storage material 33K of the third heat adjustment mechanism 33. As a result, the high-temperature gaseous refrigerant passing through the third heat adjustment mechanism 33 is pre-cooled in advance and supplied to the outdoor heat exchanger 21. Further, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80 to put the first thermoelectric element 31H in an endothermic (cooling) state and cool the heat adjustment plate 31P of the first heat adjustment mechanism 31. As a result, as described with reference to FIG. 2, the outside air (air F) supplied to the outdoor heat exchanger 21 by the outdoor blower fan 22 is cooled when passing through the through holes 31Pa of the heat adjustment plate 31P that has been cooled, and the further cooled air F is supplied to the outdoor heat exchanger 21. That is, the gaseous refrigerant preliminarily cooled by the third heat adjustment mechanism 33 is efficiently liquefied by exchanging heat with the air F whose temperature is lower than the outside air temperature immediately before the outdoor heat exchanger 21. In this case, compared with the case where the high-temperature gaseous refrigerant is directly supplied from the compressor 23 without the third heat adjustment mechanism 33 and the first heat adjustment mechanism 31, effective heat exchange of the refrigerant is possible in the outdoor heat exchanger 21 even in the same environment.

[0061] As a result of heat exchange in the outdoor heat exchanger 21, the refrigerant that has changed to a medium-temperature and high-pressure liquid state is supplied to the expansion valve 28 via the first three-way valve 29 and the receiver tank 34. Then, the liquid refrigerant that has been expanded by the expansion valve 28 and has become low-temperature is supplied to the indoor heat exchanger 41. And as a result of heat exchange in the indoor heat exchanger 41, cold air can be discharged into the room. The refrigerant discharged from the indoor heat exchanger 41 passes through the first on-off valve 26 in the fully open state and the four-way valve 25 and is returned to the compressor 23 via the accumulator 24. When the air conditioner 10 is operating in normal-load cooling mode, the second on-off valve 27 is controlled to the fully closed state, so the refrigerant does not flow through the third pipe 53, the fourth pipe 54, and the fifth pipe 55, and the low-temperature and low-pressure gaseous refrigerant discharged from the indoor heat exchanger 41 flows toward the accumulator 24 side and is returned to the compressor 23. During normal-load cooling operation, the third pipe 53, the fourth pipe 54, the second heat adjustment mechanism 32, the second on-off valve 27, and the second three-way valve 30 are not used.

[0062] In this way, by using the first heat adjustment mechanism 31 and the third heat adjustment mechanism 33 during normal-load cooling operation, the air conditioner 10 can lower the temperature of the refrigerant to liquefy it, so the operation of the outdoor heat exchanger 21 can be performed in a state less affected by the outside air temperature. That is, it becomes possible to improve the liquefaction efficiency of the refrigerant in the outdoor heat exchanger 21, and even if an outdoor heat exchanger 21 with a reduced heat exchange capacity is used, the same heat exchange performance as before can be obtained. That is, it is possible to perform cooling operation while realizing miniaturization of the outdoor unit and avoiding a decrease in operation efficiency and operation capacity. When the temperature of the air F (outside air) is lowered to a temperature sufficient for liquefying the refrigerant by cooling in the first heat adjustment mechanism 31, the third heat adjustment mechanism 33 may not be driven. In this case, the power consumption by the third thermoelectric element 33H can be reduced, contributing to a reduction in operation cost.

[0063] Subsequently, with reference to FIG. 6, the cooling operation of the air conditioner 10 in the low-load state will be described together with the refrigerant flow pattern.

[0064] As described above, the air conditioner 10 constantly monitors the indoor temperature and determines whether the indoor temperature has reached the set temperature set by a remote controller or the like operated by the user. In the case of a conventional air conditioner, when it is determined that the indoor temperature has reached the set temperature, control may be implemented to temporarily stop the operation. For example, when it can be considered that the indoor temperature has reached the set temperature during the cooling operation under the normal load as described above, the cooling operation is temporarily stopped so that the room temperature does not drop further. Then, when the temperature difference between the indoor temperature and the set temperature exceeds a predetermined value (when the room temperature has risen during the stop), the cooling operation is restarted, and ON / OFF control may be performed again so that the indoor temperature becomes the set temperature.

[0065] However, when the cooling operation of the air conditioner is stopped, the dehumidification amount decreases during the stop period, and the humidity may increase, giving discomfort to the user. In addition, repeated frequent stops and restarts of the operation cause an increase in power consumption.

[0066] Therefore, the air conditioner 10 of this embodiment performs a low-load cooling operation that reduces the rotation amount of the compressor 23 to reduce the refrigerant circulation amount. When it is determined that the indoor temperature has reached the set temperature, for example, the indoor blower fan 42 is operated at a gentle breeze to reduce the amount of cold air blown into the room and suppress the drop in the room temperature. However, at this time, since the low-temperature liquid refrigerant is supplied to the indoor heat exchanger 41, it is possible to continue to cause dew condensation on the surface of the indoor heat exchanger 41, and dehumidification can be continuously performed by collecting the generated dew condensation. That is, while maintaining the indoor temperature and suppressing a decrease in the dehumidification amount by continuing the cooling operation with a gentle breeze in a state where the refrigerant circulation amount is reduced, a low-load cooling operation function, that is, a non-stop cooling operation function, is provided to avoid repeated frequent operation stops and restarts. However, in this case, since the heat exchange efficiency of the indoor heat exchanger 41 decreases, the possibility of the liquid refrigerant flowing out of the indoor heat exchanger 41 increases. As a result, the liquid refrigerant may return to the compressor 23, which may cause a so-called "liquid back" that can cause a decrease in the efficiency of the compressor 23. The air conditioner 10 of this embodiment also realizes prevention of liquid back by using the second heat adjustment mechanism 32.

[0067] Hereinafter, the details of the low-load cooling operation will be described. When the low-load cooling operation is performed, since the air conditioner 10 is already performing a normal-load cooling operation, the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 are operating. When the control device 14 determines that the indoor temperature has reached the set temperature during the normal-load cooling operation, it switches the control state of the cooling operation from the normal-load state to the low-load state.

[0068] When the low-load cooling operation is started, the valve control unit 96 controls the four-way valve drive circuit 74, the first three-way valve drive circuit 78, and the second three-way valve drive circuit 79 to change the direction in which the refrigerant flows in the four-way valve 25, the first three-way valve 29, and the second three-way valve 30 for low-load cooling. That is, the four-way valve 25 and the first three-way valve 29 maintain the switching state during normal-load cooling, and the second three-way valve 30 connects the 15th region 54c of the fourth pipe 54 and the fifth pipe 55. The valve control unit 96 controls the expansion valve drive circuit 77 to adjust the refrigerant expansion rate of the expansion valve 28 during the low-load cooling operation. Further, the valve control unit 96 controls the first on-off valve drive circuit 75 and the second on-off valve drive circuit 76 to change the on-off valve states of the first on-off valve 26 and the second on-off valve 27 according to the up and down changes of the room temperature with respect to the set temperature. Also, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82 to control the control states of the first thermoelectric element 31H, the second thermoelectric element 32H, and the third thermoelectric element 33H for low-load cooling.

[0069] In the low-load cooling operation, the compressor control unit 95 reduces the frequency of the compressor 23 to decrease the circulation amount of the refrigerant. The outdoor fan control unit 93 reduces the rotational speed of the outdoor air supply fan 22 for low-load cooling operation, for example, according to the decreased circulation amount of the refrigerant. Also, as described above, the indoor fan control unit 94 adjusts to reduce the rotational speed of the indoor air supply fan 42, reduces the amount of cold air blown into the room, and suppresses the room temperature from dropping too much to maintain the room temperature at the set temperature. In this case, in the indoor heat exchanger 41, since the heat exchange efficiency decreases, the gasification rate of the refrigerant may decrease and the refrigerant in the gas-liquid two-phase state may flow out of the indoor heat exchanger 41.

[0070] In the low-load cooling operation, the flow pattern of the refrigerant from the compressor 23 to the outdoor heat exchanger 21, the first three-way valve 29, the receiver tank 34, the expansion valve 28, and the indoor heat exchanger 41 is the same as that in the above-described normal-load cooling operation. Specifically, the four-way valve 25 connects the fourth region 51d and the fifth region 51e of the first pipe 51, and connects the discharge port 23b of the compressor 23 and the opening 33a of the third heat adjustment mechanism 33. As a result, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23 is supplied to the outdoor heat exchanger 21 side.

[0071] The valve control unit 96 controls the first three-way valve drive circuit 78, maintains the connection between the tenth region 52d and the ninth region 52c of the second pipe 52 by the first three-way valve 29 (the first connection state), and maintains the connection between the outdoor heat exchanger 21 and the receiver tank 34. Then, the valve control unit 96 controls the expansion valve drive circuit 77, controls the opening degree of the expansion valve 28, and adjusts the expansion state of the liquid refrigerant supplied from the receiver tank 34.

[0072] At this time, as described above, the thermoelectric element control unit 97 controls the third thermoelectric element drive circuit 82 to put the third thermoelectric element 33H in an endothermic (cooling) state, and cools the second heat storage material 33K of the third heat adjustment mechanism 33. As a result, the high-temperature gaseous refrigerant passing through the third heat adjustment mechanism 33 is pre-cooled and supplied to the outdoor heat exchanger 21. Further, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80 to put the first thermoelectric element 31H in an endothermic (cooling) state, and cools the heat adjustment plate 31P of the first heat adjustment mechanism 31. That is, the gas-liquid two-phase refrigerant cooled by the third heat adjustment mechanism 33 is liquefied more easily by exchanging heat with the air F whose temperature is lower than the outside air temperature in the outdoor heat exchanger 21. In this case, compared with the case where the high-temperature gaseous refrigerant is directly supplied from the compressor 23 without the third heat adjustment mechanism 33 and the first heat adjustment mechanism 31, heat exchange using the low-temperature refrigerant becomes possible in the outdoor heat exchanger 21. During low-load cooling operation, since the amount of refrigerant circulating in the refrigerant pipe 13 is reduced, sufficient liquefaction (condensation) effect may be obtained by heat exchange in the outdoor heat exchanger 21 using the cooling air by the first heat adjustment mechanism 31. In this case, the heating function by the third heat adjustment mechanism 33 (the third thermoelectric element 33H) may be stopped. In this case, the energy-saving operation performance can be improved.

[0073] As a result of heat exchange in the outdoor heat exchanger 21, the refrigerant that has changed to a medium-temperature and high-pressure liquid state is supplied to the expansion valve 28 via the first three-way valve 29 and the receiver tank 34. Then, the liquid refrigerant that has been expanded by the expansion valve 28 and has become low-temperature is supplied to the indoor heat exchanger 41. The low-temperature liquid refrigerant supplied to the indoor heat exchanger 41 has its cold air blowing amount reduced by the gentle breeze supplied from the indoor blower fan 42 as described above, and heat exchange is suppressed and gasification is reduced, but dew condensation can occur on the surface of the indoor heat exchanger 41. Then, by collecting the generated dew condensation, dehumidification of the room can be continuously performed.

[0074] Here, when the room temperature relative to the set temperature is excessively cooled by a predetermined value or more during low-load cooling operation, for example, when it is excessively cooled by 1°C relative to the set temperature, there is a possibility of liquid backflow to the compressor 23 side. Therefore, it is necessary to vaporize the refrigerant flowing out from the indoor heat exchanger 41. Thus, in order to avoid the liquid refrigerant directly returning to the compressor 23 side, the valve control unit 96 controls the first on-off valve drive circuit 75 to fully close the first on-off valve 26, and controls the second on-off valve drive circuit 76 to perform opening valve control (i.e., opening degree control) on the second on-off valve 27. As a result, the gas-liquid two-phase or liquid refrigerant flowing out from the outdoor heat exchanger 21 flows from the first region 51a of the first pipe 51 to the thirteenth region 54a of the fourth pipe 54 and passes through the second heat adjustment mechanism 32. At this time, by heating the first heat storage material 32K of the second heat adjustment mechanism 32 with the second thermoelectric element 32H in advance, the refrigerant passing through the fourth pipe 54 can be heated to promote vaporization. Also, the valve control unit 96 controls the second on-off valve drive circuit 76 to perform opening valve control on the second on-off valve 27, and controls the second three-way valve drive circuit 79 to connect the fifteenth region 54c of the fourth pipe 54 to the fifth pipe 55 so that the refrigerant flows into the third pipe 53. At this time, since the first three-way valve 29 is not connected (communicated) to the third pipe 53, the refrigerant flowing through the fifth pipe 55 flows into the twelfth region 53b of the third pipe 53 and passes through the second heat adjustment mechanism 32 again. That is, also at this time, the refrigerant is heated and vaporization is promoted.

[0075] At this time, since the first on-off valve 26 is in the fully closed state, the refrigerant whose vaporization is promoted and which passes through the second heat adjustment mechanism 32 and flows through the eleventh region 53a of the third pipe 53 does not flow to the four-way valve 25 side, but flows into the third region 51c of the first pipe 51 and returns to the accumulator 24, that is, the compressor 23 side. In this way, in the air conditioner 10, even when the indoor temperature drops below the set temperature and low-load cooling operation is performed, and it becomes necessary to suppress the heat exchange of the indoor heat exchanger 41, it is possible to suppress liquid backflow to the compressor 23 side.

[0076] On the one hand, when the room temperature with respect to the set temperature rises above a predetermined value during low-load cooling operation, for example, when it rises by 1°C with respect to the set temperature, the valve control unit 96 controls the expansion valve drive circuit 77, adjusts the opening degree of the expansion valve 28, and increases the amount of the low-temperature refrigerant liquid supplied to the indoor heat exchanger 41. Further, the indoor fan control unit 94 controls the indoor fan drive circuit 72, increases the air volume of the indoor blower fan 42, increases the heat exchange by the indoor heat exchanger 41, promotes the gasification of the refrigerant, increases the amount of cold air blown into the room, and performs a downward adjustment of the room temperature.

[0077] In this case, the valve control unit 96 controls the second on-off valve drive circuit 76 to fully close the second on-off valve 27 and controls the first on-off valve drive circuit 75 to open the first on-off valve 26. That is, the refrigerant is prevented from flowing through the fourth pipe 54 and the third pipe 53. As a result, the gasified refrigerant flowing out from the first region 51a of the first pipe 51 from the indoor heat exchanger 41 passes through the first on-off valve 26 and the four-way valve 25 and flows into the third region 51c of the first pipe 51 and returns to the accumulator 24, that is, the compressor 23 side. In this case, even if the refrigerant flowing out from the indoor heat exchanger 41 contains a little liquid refrigerant, since the gas refrigerant and the liquid refrigerant are separated by the accumulator 24, it is possible to avoid the liquid refrigerant from returning to the compressor 23. That is, the connection state of the refrigerant pipe 13 is temporarily returned to the same state as during normal-load cooling.

[0078] Thus, even when fine adjustment of the room temperature with respect to the set temperature is required during the low-load cooling operation of the air conditioner 10, if necessary, the second heat adjustment mechanism 32 is used to vaporize the refrigerant returning to the compressor 23 side, so that liquid backflow to the compressor 23 can be suppressed. Also, in the low-load cooling operation, since the operation (refrigerant circulation) of the air conditioner 10 is not stopped, it is possible to suppress the power consumption caused by maintaining the dehumidifying performance and repeating the stop and restart of the operation. And, as described above, during the low-load cooling operation of the air conditioner 10, the second heat adjustment mechanism 32 functions as an evaporator that warms the first heat storage material 32K with the second thermoelectric element 32H to vaporize the liquid refrigerant. Further, the third heat adjustment mechanism 33 cools the second heat storage material 33K with the third thermoelectric element 33H to assist in liquefying the refrigerant, which can also contribute to downsizing the outdoor heat exchanger 21 and thus the outdoor unit 11.

[0079] Subsequently, with reference to FIG. 7, the heating operation of the air conditioner 10 in the normal load state will be described together with the refrigerant flow pattern.

[0080] In the case of normal load heating operation, when the start of the air conditioner 10 and the start of the heating operation are simultaneous, the outdoor air supply fan 22, the compressor 23, and the indoor air supply 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 air supply fan 22, the indoor air supply fan 42, and the compressor 23 at the start of the heating operation.

[0081] During the normal load heating operation, the outdoor fan control unit 93 adjusts the rotation speed of the outdoor air supply fan 22. The indoor fan control unit 94 adjusts the rotation speed of the indoor air supply fan 42. For example, the indoor fan control unit 94 controls the indoor air supply fan 42 between weak wind (low speed) operation and strong wind (high speed) operation according to the temperature of the room where the indoor unit 12 is installed or a signal input from the remote controller, and the compressor control unit 95 adjusts the frequency of the compressor 23.

[0082] When the normal load heating operation is started, the valve control unit 96 controls the four-way valve drive circuit 74, the first three-way valve drive circuit 78, and the second three-way valve drive circuit 79 to change the direction in which the refrigerant flows in the four-way valve 25, the first three-way valve 29, and the second three-way valve 30 for normal load heating. Further, the valve control unit 96 controls the first on-off valve drive circuit 75, the second on-off valve drive circuit 76, and the expansion valve drive circuit 77 to change the opening and closing states of the first on-off valve 26, the second on-off valve 27, and the expansion valve 28 for normal load heating. Further, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82 to control the control states of the first thermoelectric element 31H, the second thermoelectric element 32H, and the third thermoelectric element 33H for normal load heating.

[0083] Specifically, the four-way valve 25 connects the fourth region 51d of the first pipe 51 and the second region 51b, and connects the discharge port 23b of the compressor 23 and the first on-off valve 26. Further, the valve control unit 96 controls the first on-off valve drive circuit 75 to fully open the first on-off valve 26. As a result, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23 is supplied to the indoor heat exchanger 41 side. As a result, during the heating operation, the indoor heat exchanger 41 functions as a condenser and discharges warm air into the room as a result of heat exchange.

[0084] In addition, the valve control unit 96 controls the second on-off valve drive circuit 76 to fully close the second on-off valve 27. In this case, in the fourth pipe 54, the refrigerant does not flow, but since the first region 51a of the first pipe 51 and the thirteenth region 54a of the fourth pipe 54 communicate with each other, the temperature of the refrigerant inside the thirteenth region 54a can be increased by the high-temperature refrigerant flowing through the first region 51a. Along with this, the temperature of the first heat storage material 32K of the second heat adjustment mechanism 32 can be increased (preheated). In this case, the temperature of the first heat storage material 32K may be increased using the second thermoelectric element 32H. By preheating the first heat storage material 32K, when defrosting or snow removal of the outdoor heat exchanger 21 described later becomes necessary, it becomes possible to supply warm refrigerant to the outdoor heat exchanger 21 from the start of defrosting / snow removal control, and rapid defrosting and snow removal can be realized.

[0085] The expansion valve control unit 96 controls the expansion valve drive circuit 77 and adjusts the valve opening state of the expansion valve 28, thereby changing the medium-temperature and high-pressure gaseous refrigerant heat-exchanged in the indoor heat exchanger 41 into a low-temperature and low-pressure liquid refrigerant. Then, the low-temperature and low-pressure liquid refrigerant is supplied to the outdoor heat exchanger 21 via the receiver tank 34 and the first three-way valve 29.

[0086] In the case of heating operation, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80 to put the first thermoelectric element 31H in a heat generation state and heat the heat adjustment plate 31P of the first heat adjustment mechanism 31. As a result, the outside air (air F) supplied to the outdoor heat exchanger 21 by the outdoor blower fan 22 is heated when passing through the through holes 31Pa of the heated heat adjustment plate 31P and is supplied to the outdoor heat exchanger 21. That is, the liquid refrigerant cooled by passing through the expansion valve 28 is vaporized by heat-exchanging with the air F that has become higher than the outside air temperature in the outdoor heat exchanger 21 functioning as an evaporator and flows out to the compressor 23 side (the third heat adjustment mechanism 33 side). That is, even when the outside air temperature is low, the influence of the low temperature can be mitigated, and the vaporization efficiency in the outdoor heat exchanger 21 can be improved. Note that the thermoelectric element control unit 97 controls the third thermoelectric element drive circuit 83 to put the third thermoelectric element 33H in a heat generation state and heat the second heat storage material 33K of the third heat adjustment mechanism 33. As a result, even if a liquid refrigerant remains as a result of the heat exchange in the outdoor heat exchanger 21, it can be vaporized by the third heat adjustment mechanism 33, and it is possible to suppress liquid backflow to the compressor 23 side. Note that the fifth region 51e of the first pipe 51 is connected to the third region 51c of the first pipe 51 and the eleventh region 53a of the third pipe 53 via the four-way valve 25, but the first three-way valve 29 does not connect the twelfth region 53b of the third pipe 53 to another pipe. Therefore, the refrigerant that has passed through the third heat adjustment mechanism 33 flows into the third region 51c of the first pipe 51 after passing through the four-way valve 25 and then flows to the accumulator 24 (compressor 23 side). Note that the second three-way valve 30 and the fifth pipe 55 are not used during normal load heating operation.

[0087] The air conditioner 10 of the present embodiment can be configured such that frost hardly adheres to the outdoor heat exchanger 21 by including the first heat adjustment mechanism 31. Therefore, the air conditioner 10 of the present embodiment can basically be configured not to require defrosting.

[0088] As described above, during normal load heating operation, the air conditioner 10 can vaporize the refrigerant by using the first heat adjustment mechanism 31 and the third heat adjustment mechanism 33 due to superheat of the refrigerant. Therefore, compared to the case where the low-temperature liquid refrigerant is directly supplied from the indoor heat exchanger 41 side (receiver tank 34) to the outdoor heat exchanger 21 without the first heat adjustment mechanism 31 and the third heat adjustment mechanism 33, even in the same environment, equivalent or more effective vaporization (heat exchange) of the refrigerant can be achieved in the outdoor heat exchanger 21. That is, heating operation can be performed in a state less affected by the outside air temperature. Also, it becomes possible to improve the vaporization efficiency of the refrigerant with the outdoor heat exchanger 21 and the third heat adjustment mechanism 33, and the same heat exchange performance as before can be obtained even when using the outdoor heat exchanger 21 with reduced heat exchange capacity. That is, heating operation can be performed while realizing downsizing of the outdoor unit and avoiding a decrease in operation efficiency and operation capacity. When the temperature of the air F (outside air) is raised to a temperature sufficient for vaporization of the refrigerant by heating (heat generation) in the first heat adjustment mechanism 31, the third heat adjustment mechanism 33 may be non-driven. In this case, power consumption by the third thermoelectric element 33H can be reduced, contributing to a reduction in operation cost.

[0089] Subsequently, with reference to FIG. 8, the heating operation of the air conditioner 10 in the low load state will be described together with the refrigerant flow pattern.

[0090] Even during the heating operation, as described above, the air conditioner 10 constantly monitors the indoor temperature and determines whether the indoor temperature has reached the set temperature set by a remote controller or the like operated by the user. In the case of a conventional air conditioner, when it is determined that the indoor temperature has reached the set temperature, control may be implemented to temporarily stop the operation. For example, when it can be considered that the indoor temperature has reached the set temperature during the normal load heating operation as described above, the heating operation is temporarily stopped so that the room temperature does not become hotter. Then, when the temperature difference between the indoor temperature and the set temperature exceeds a predetermined value (when the room temperature has dropped during the stop), the heating operation may be restarted, and ON / OFF control may be performed again so that the indoor temperature becomes the set temperature.

[0091] However, when the heating operation of the air conditioner 10 is stopped, the humidity may increase during the stop period, giving the user a sense of discomfort. In addition, the repeated frequent stop and restart of the operation may cause an increase in power consumption.

[0092] Therefore, the air conditioner 10 of the present embodiment performs a low-load heating operation that reduces the rotation amount of the compressor 23 to reduce the refrigerant circulation amount. When it is determined that the indoor temperature has reached the set temperature, for example, the indoor blower fan 42 is operated at a low air volume to reduce the amount of warm air blown into the room and suppress the rise in the room temperature. That is, while continuing the heating operation at a low air volume in a state where the refrigerant circulation amount is reduced, the indoor temperature is maintained and the rise in humidity is suppressed, and a low-load heating operation function, that is, a non-stop heating operation function, is provided to avoid repeated frequent operation stops and restarts. Note that when the liquid refrigerant that has flowed out of the indoor heat exchanger 41 and has been cooled by passing through the expansion valve 28 returns to the outdoor heat exchanger 21, it may cause frosting of the outdoor heat exchanger 21. Therefore, the air conditioner 10 of the present embodiment does not allow the liquid refrigerant cooled by passing through the expansion valve 28 to flow into the outdoor heat exchanger 21, vaporizes it by passing through the second heat adjustment mechanism 32, and returns it to the accumulator 24 (on the compressor 23 side). That is, it has a structure that suppresses the generation of frost in the outdoor heat exchanger 21 due to the low-temperature refrigerant.

[0093] Hereinafter, the details of the low-load heating operation will be described. When the low-load heating operation is performed, since the air conditioner 10 is already performing a heating operation at a normal load, the outdoor blower fan 22, the compressor 23, and the indoor blower fan 42 are operating. When the control device 14 determines that the indoor temperature has reached the set temperature during the normal-load heating operation, it switches the control state of the heating operation from the normal-load state to the low-load state.

[0094] When the low-load heating operation is started, the valve control unit 96 controls the four-way valve drive circuit 74, the first three-way valve drive circuit 78, and the second three-way valve drive circuit 79 to change the direction in which the refrigerant flows in the four-way valve 25, the first three-way valve 29, and the second three-way valve 30 for low-load heating. That is, the four-way valve 25 and the first three-way valve 29 maintain the switching state during general-load heating, and the first three-way valve 29 connects the ninth region 52c of the second pipe 52 to the twelfth region 53b of the third pipe 53. In addition, the second three-way valve 30 connects the fifteenth region 54c of the fourth pipe 54 to the sixteenth region 54d. Further, the valve control unit 96 controls the expansion valve drive circuit 77 to adjust the refrigerant expansion rate of the expansion valve 28 during the low-load heating operation. Also, the valve control unit 96 controls the first on-off valve drive circuit 75 and the second on-off valve drive circuit 76 to change the on-off valve state of the first on-off valve 26 and the second on-off valve 27 according to the up and down change of the room temperature with respect to the set temperature. Further, the thermoelectric element control unit 97 controls the first thermoelectric element drive circuit 80, the second thermoelectric element drive circuit 81, and the third thermoelectric element drive circuit 82 to control the control states of the first thermoelectric element 31H, the second thermoelectric element 32H, and the third thermoelectric element 33H for low-load heating.

[0095] In the low-load heating operation, the compressor control unit 95 reduces the frequency of the compressor 23 to decrease the refrigerant circulation amount. The outdoor fan control unit 93 reduces the rotation speed of the outdoor blower fan 22, for example, for the low-load heating operation according to the decreased refrigerant circulation amount. On the other hand, as described above, the indoor fan control unit 94 adjusts to reduce the rotation speed of the indoor blower fan 42, reduces the amount of warm air blown into the room, and suppresses the room temperature from rising too much to maintain the room temperature at the set temperature.

[0096] In the low-load heating operation, the flow pattern of the refrigerant from the compressor 23 to the four-way valve 25, the first on-off valve 26, the indoor heat exchanger 41, the expansion valve 28, and the receiver tank 34 is the same as that during the normal-load heating operation described above. Specifically, the four-way valve 25 connects the fourth region 51d of the first pipe 51 and the second region 51b and connects the discharge port 23b of the compressor 23 and the first on-off valve 26. As a result, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23 is supplied to the indoor heat exchanger 41 side.

[0097] The valve control unit 96 controls the first on-off valve drive circuit 75 and the second on-off valve drive circuit 76 to perform an opening control of the first on-off valve 26 and the second on-off valve 27. Further, the valve control unit 96 controls the second three-way valve drive circuit 79 to switch the second three-way valve 30 and connect the 15th region 54c of the fourth pipe 54 to the 16th region 54d. That is, the second heat adjustment mechanism 32 is connected to the outdoor heat exchanger 21 side. In this case, since the first on-off valve 26 is in an open state, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23 flows to the fourth pipe 54 side and then to the outdoor heat exchanger 21 side, so as to reduce the amount supplied to the indoor heat exchanger 41 and suppress the temperature rise in the indoor unit 12.

[0098] Here, when the room temperature drops too much during the low-load heating operation, the valve control unit 96 controls the second on-off valve drive circuit 76 to throttle the opening degree of the second on-off valve 27 so that more high-temperature refrigerant flows from the fourth pipe 54 side to the indoor heat exchanger 41. That is, the amount of high-temperature gaseous refrigerant supplied to the indoor heat exchanger 41 is increased so that the indoor temperature can rise even during the low-load heating operation in which the amount of refrigerant circulating in the refrigerant pipe 13 is suppressed. When the indoor temperature is, for example, 1 °C lower than the set temperature, the opening degree control of the expansion valve 28 is performed based on the detected value of the temperature sensor T2 on the downstream side of the indoor heat exchanger 41 functioning as a condenser and the detected value of the temperature sensor T1 on the upstream side of the indoor heat exchanger 41, and the subcooling SC is adjusted. For example, the valve control unit 96 adjusts the opening degree of the expansion valve 28 and the refrigerant flow rate so that SC = T2 - T1 ≒ 5 °C by adjusting the expansion valve drive circuit 77 to adjust the temperature of the warm air blown out.

[0099] Conversely, when the room temperature rises too much during low-load heating operation, the valve control unit 96 controls the second on-off valve drive circuit 76 to increase the opening degree of the second on-off valve 27 so that more high-temperature refrigerant than the indoor heat exchanger 41 flows to the fourth pipe 54 side. That is, the amount of high-temperature gaseous refrigerant supplied to the indoor heat exchanger 41 is reduced to suppress the rise in the indoor temperature. When the indoor temperature becomes, for example, 1°C higher than the set temperature, the opening degree of the expansion valve 28 is controlled based on the detection value of the temperature sensor Su arranged at the inlet portion of the accumulator 24 and the detection value of the temperature sensor T3 arranged inside the outdoor heat exchanger 21, and the heating degree SH is adjusted. For example, the valve control unit 96 adjusts the opening degree of the expansion valve 28 and adjusts the refrigerant flow rate by controlling the expansion valve drive circuit 77 so that SH = Su - T3 ≒ 3°C, and adjusts the temperature of the warm air blown out.

[0100] In this way, by adjusting the amount of high-temperature refrigerant supplied to the indoor heat exchanger 41, the heat exchange efficiency of the indoor heat exchanger 41 is controlled, and the frequency of ON / OFF control of the air conditioner 10 for temperature adjustment is reduced. Also, as shown in FIG. 8, a part of the high-temperature gaseous refrigerant discharged from the compressor 23 is supplied to the outdoor heat exchanger 21 via the second heat adjustment mechanism 32 and the second on-off valve 27. Further, the low-temperature liquid refrigerant that has passed through the expansion valve 28 and the receiver tank 34 from the indoor heat exchanger 41 is sent to the second heat adjustment mechanism 32 via the first three-way valve 29. That is, the low-temperature liquid refrigerant is not supplied to the outdoor heat exchanger 21. Also, the outdoor heat exchanger 21 is supplied with the air F (outside air) heated by the first heat adjustment mechanism 31. As a result, it is possible to suppress the formation of frost on the outdoor heat exchanger 21 during heating operation. Also, even when defrosting is necessary or when snow falls and snow removal is necessary, the opening degree of the second on-off valve 27 is increased, and the amount of high-temperature gaseous refrigerant from the compressor 23 supplied to the outdoor heat exchanger 21 is increased, so that defrosting and snow removal can be performed efficiently and quickly.

[0101] Note that the second heat adjustment mechanism 32 heats the first heat storage material 32K with the high-temperature gaseous refrigerant flowing through the fourth pipe 54. The first heat storage material 32K can be heat-stored (heated) by the second thermoelectric element 32H. Therefore, the low-temperature liquid refrigerant flowing from the receiver tank 34 to the third pipe 53 is heat-exchanged and vaporized by the second heat adjustment mechanism 32, passes through the third region 51c of the first pipe 51, and is returned to the accumulator 24 (on the compressor 23 side). In this case, since the first heat storage material 32K of the second heat adjustment mechanism 32 can be heat-stored with the high-temperature refrigerant discharged from the compressor 23, it can also contribute to suppressing the increase in size of the second heat adjustment mechanism 32. Note that the substantially gaseous refrigerant that has passed through the second heat adjustment mechanism 32 is supplied to the outdoor heat exchanger 21. The refrigerant that has passed through the outdoor heat exchanger 21 is supplied to the third heat adjustment mechanism 33 via the sixth region 51f of the first pipe 51. The second heat storage material 33K of the third heat adjustment mechanism 33 can be heat-stored (heated) by the third thermoelectric element 33H, and can be vaporized by the third heat adjustment mechanism 33 even if liquid is mixed in the refrigerant that has passed through the outdoor heat exchanger 21. It merges with the gaseous refrigerant that passes through the third pipe 53 and is returned, and is returned to the accumulator 24 (on the compressor 23 side). That is, the third heat adjustment mechanism 33 assists in vaporizing the refrigerant returned to the accumulator 24 (on the compressor 23 side). Also in this regard, it can contribute to reducing the size of the outdoor heat exchanger 21, and thus the size of the outdoor unit 11.

[0102] The air conditioner 10 according to the embodiment described above includes an outdoor heat exchanger 21, an indoor heat exchanger 41, a first pipe 51, a second pipe 52, a compressor 23, a four-way valve 25, an expansion valve 28, and a first heat adjustment mechanism 31. The outdoor heat exchanger 21 is provided in the outdoor unit 11. The indoor heat exchanger 41 is provided in the indoor unit 12. The first pipe 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21, and refrigerant flows through it. The second pipe 52 connects the outdoor heat exchanger 21 and the indoor heat exchanger 41, and refrigerant flows through it. The compressor 23 is provided in the first pipe 51 and has a suction port 23a for sucking refrigerant and a discharge port 23b for discharging refrigerant. The four-way valve 25 is provided in the first pipe 51 and can change the direction in which refrigerant flows. The expansion valve 28 is provided in the second pipe 52. The first heat adjustment mechanism 31 is arranged on the upstream side of the flow of air F passing through the outdoor heat exchanger 21 when causing heat exchange in the outdoor heat exchanger 21, and cools or heats the air F flowing toward the outdoor heat exchanger 21. According to this configuration, for example, an air conditioner 10 can be obtained that is less affected by the outside air temperature, realizes miniaturization of the outdoor unit, and can avoid a decrease in operating efficiency and a decrease in operating capacity.

[0103] Further, the first heat adjustment mechanism 31 of the air conditioner 10 may include, for example, a heat adjustment plate 31P in which a through hole 31Pa through which air can pass is formed, and a first thermoelectric element 31H (thermoelectric element for the plate) that changes the temperature of the heat adjustment plate 31P. According to this configuration, for example, cooling of air (outside air) during cooling operation and heating of air (outside air) during heating operation can be easily controlled.

[0104] Further, the air conditioner 10 includes, for example, a first on-off valve 26 disposed in a first pipe 51 between a four-way valve 25 and an indoor heat exchanger 41, a first pipe 51 between the four-way valve 25 and the suction port 23a of a compressor 23, a second pipe 52 between an expansion valve 28 and an outdoor heat exchanger 21, a third pipe 53 connecting the second pipe 52 and the first pipe 51, a first three-way valve 29 disposed at the connection position between the second pipe 52 and the third pipe 53 for switching between a first connection state connecting the indoor heat exchanger 41 and the outdoor heat exchanger 21 and a second connection state connecting the indoor heat exchanger 41 and the third pipe 53, a fourth pipe 54 connecting the first pipe 51 between the first on-off valve 26 and the indoor heat exchanger 41 and the second pipe 52 between the first three-way valve 29 and the outdoor heat exchanger 21, a second on-off valve 27 provided in the fourth pipe 54, a fifth pipe 55 connecting the fourth pipe 54 between the connection position of the second on-off valve 27 and the second pipe 52 and the third pipe 53, and a second three-way valve 30 provided at the connection position between the fourth pipe 54 and the fifth pipe 55 for switching between a third connection state connecting the first pipe 51 and the second pipe 52 and a fourth connection state connecting the first pipe 51 and the fifth pipe 55, and a second heat adjustment mechanism 32 provided across the third pipe 53 and the fourth pipe 54 and capable of heating the refrigerant flowing through the third pipe 53 or the refrigerant flowing through the fourth pipe 54. According to this configuration, for example, it is possible to warm the refrigerant returning to the compressor 23 side via the second heat adjustment mechanism 32, and it is possible to suppress the liquid refrigerant from returning to the compressor 23.

[0105] Further, the air conditioner 10 may include, for example, a third heat adjustment mechanism provided in the first pipe 51 between the four-way valve 25 and the outdoor heat exchanger 21 and capable of cooling or heating the refrigerant flowing through the first pipe 51. According to this configuration, for example, it is possible to bear a part of the heat exchange by the outdoor heat exchanger 21, so that the required capacity of the outdoor heat exchanger 21 can be reduced, contributing to miniaturization.

[0106] Further, the third heat adjustment mechanism 33 of the air conditioner 10 may include, for example, a second heat storage material 33K in contact with the first pipe 51 and a third thermoelectric element 33H (thermoelectric element for heat storage material) that transfers heat to the second heat storage material 33K. According to this configuration, for example, it is possible to easily perform pre-cooling control of the refrigerant during cooling operation and heating control for gasification of the refrigerant during heating operation.

[0107] Although some 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 implemented in various other forms, and various omissions, replacements, and changes 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 also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0108] 10... air conditioner, 11... outdoor unit, 12... indoor unit, 13... refrigerant pipe, 14... control device, 21... outdoor heat exchanger, 23... compressor, 24... accumulator, 25... four-way valve, 26... first on-off valve, 27... second on-off valve, 28... expansion valve, 29... first three-way valve, 30... second three-way valve, 31... first heat adjustment mechanism, 31H... first thermoelectric element (thermoelectric element for plate), 31P... heat adjustment plate, 31Pa... through hole, 32... second heat adjustment mechanism, 32H... second thermoelectric element, 32K... first heat storage material, 33... third heat adjustment mechanism, 33H... third thermoelectric element (thermoelectric element for heat storage material), 33K... second heat storage material, 41... indoor heat exchanger, 51... first pipe, 52... second pipe, 53... third pipe, 54... fourth pipe, 55... fifth pipe.

Claims

1. An outdoor heat exchanger provided in an outdoor unit, An indoor heat exchanger provided in an indoor unit, A first pipe that connects the indoor heat exchanger and the outdoor heat exchanger and through which a refrigerant flows, A second pipe that connects the outdoor heat exchanger and the indoor heat exchanger and through which the refrigerant flows, A compressor provided in the first pipe, having a suction port for sucking the refrigerant and a discharge port for discharging the refrigerant, A four-way valve provided in the first pipe and capable of changing the direction in which the refrigerant flows, An expansion valve provided in the second pipe, A first heat adjustment mechanism arranged on the upstream side of the air flow passing through the outdoor heat exchanger when performing heat exchange with the outdoor heat exchanger and capable of cooling or heating the air flowing toward the outdoor heat exchanger, An air conditioner comprising the above.

2. The air conditioner according to claim 1, wherein the first heat adjustment mechanism includes a heat adjustment plate formed with a through hole through which the air can pass, and a thermoelectric element for the plate that changes the temperature of the heat adjustment plate.

3. A first on-off valve arranged in the first pipe between the four-way valve and the indoor heat exchanger, A third pipe connecting the first pipe between the four-way valve and the suction port of the compressor and the second pipe between the expansion valve and the outdoor heat exchanger, A first three-way valve arranged at the connection position between the second pipe and the third pipe and switching between a first connection state connecting the indoor heat exchanger and the outdoor heat exchanger and a second connection state connecting the indoor heat exchanger and the third pipe, A fourth pipe connecting the first pipe between the first on-off valve and the indoor heat exchanger and the second pipe between the first three-way valve and the outdoor heat exchanger, A second on-off valve provided in the fourth pipe, A fifth pipe connecting the fourth pipe between the connection position of the second on-off valve and the second pipe and the third pipe, A second three-way valve provided at the connection position between the fourth pipe and the fifth pipe and switching between a third connection state connecting the first pipe and the second pipe and a fourth connection state connecting the first pipe and the fifth pipe, A second heat adjustment mechanism provided across the third pipe and the fourth pipe and capable of heating the refrigerant flowing through the third pipe or the refrigerant flowing through the fourth pipe, The air conditioner according to claim 1, comprising the above.

4. The air conditioner according to claim 1, further comprising a third heat adjustment mechanism provided in the first pipe between the four-way valve and the outdoor heat exchanger and capable of cooling or heating the refrigerant flowing through the first pipe.

5. The air conditioner according to claim 4, wherein the third heat adjustment mechanism includes a heat storage material in contact with the first pipe and a thermoelectric element for the heat storage material that transfers heat to the heat storage material.

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