Air conditioner

Abstract

To provide an air conditioner capable of smoothly obtaining comfortable feeling while suppressing increase in necessary capacity during a cooling operation.SOLUTION: An air conditioner includes an indoor unit, an outdoor unit, first piping, second piping, a compressor, a four-way valve, an expansion valve, third piping, fourth piping, a first auxiliary heat exchanger, a second auxiliary heat exchanger, circulation air course piping and an auxiliary fan. The third piping connects the first piping between the four-way valve and a suction port of the compressor and the second piping between the expansion valve and the indoor heat exchanger. The fourth piping connects the first piping between the four-way valve and the outdoor heat exchanger and the second piping between the expansion valve and the outdoor heat exchanger. The first auxiliary heat exchanger is provided in the third piping, and the second auxiliary heat exchanger is provided in the fourth piping. The circulation air course piping enables air taken in on an indoor side on which the indoor unit is provided to pass through the first auxiliary heat exchanger and the second auxiliary heat exchanger in this order and return to the indoor side. The auxiliary fan is provided in a portion of the circulation air course piping to cause the air to flow between the indoor side and the outdoor unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an air conditioning apparatus. [Background technology]

[0002] Air conditioning devices such as air conditioners regulate indoor temperatures by absorbing and releasing heat through the condensation and evaporation of refrigerant in a refrigeration cycle. During cooling operation, the refrigerant condenses in the outdoor heat exchanger (condenser) and evaporates in the indoor heat exchanger (evaporator). During heating operation, the refrigerant evaporates in the outdoor heat exchanger (evaporator) and condenses in the indoor heat exchanger (condenser). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-32106 Summary of the Invention [Problem to be solved by the invention]

[0004] Air conditioners such as those described above may simultaneously perform heat (sensible heat) processing and water vapor (latent heat) processing to create a comfortable indoor environment. For example, when the air conditioner is operating in cooling mode and the indoor air humidity is high (e.g., when the outdoor humidity is high in summer), energy is consumed in water vapor processing for dehumidification, and the heat (sensible heat) processing that causes the indoor temperature to drop may not proceed smoothly. In other words, the damp feeling is difficult to eliminate, and it may take a long time to create the comfortable environment that users expect. As a result, there is a problem that high-load operation or the installation of a large air conditioner is required to achieve a comfortable feeling in a short period of time, which easily leads to an increase in the required capacity.

[0005] One example of a problem to be solved by the present invention is to provide an air conditioner that can smoothly provide a comfortable feeling while suppressing an increase in the required capacity during cooling operation. [Means for solving the problem]

[0006] An air conditioner according to one embodiment of the present invention includes an indoor unit, an outdoor unit, a first pipe, a second pipe, a compressor, a four-way valve, an expansion valve, a third pipe, a fourth pipe, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a circulation air duct pipe, and an auxiliary fan. The indoor unit includes an indoor heat exchanger and an indoor blower fan. The outdoor unit includes an outdoor heat exchanger and an outdoor blower fan. The first pipe connects the indoor heat exchanger and the outdoor heat exchanger, and a refrigerant flows through it. The second pipe connects the outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows through it. The compressor is provided in the first pipe and has an inlet for drawing in the refrigerant and an outlet for discharging the refrigerant. The four-way valve is provided in the first pipe and is capable of changing the direction in which the refrigerant flows. An expansion valve is provided in the second pipe. A third pipe connects 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 indoor heat exchanger. A fourth pipe connects the first pipe between the four-way valve and the outdoor heat exchanger and the second pipe between the expansion valve and the outdoor heat exchanger. A first auxiliary heat exchanger is provided on the third pipe. A second auxiliary heat exchanger is provided on the fourth pipe. The circulation air duct pipe is capable of passing air taken in a room where the indoor unit is installed through the first auxiliary heat exchanger and the second auxiliary heat exchanger in that order and returning the air to the room. An auxiliary fan is provided in a part of the circulation air duct pipe and moves the air between the room and the outdoor unit.

[0007] Furthermore, the outdoor unit of the air conditioning system may include, for example, an outdoor main air duct section in which the outdoor heat exchanger and the outdoor blower fan are arranged, an outdoor auxiliary air duct section provided above the outdoor main air duct section in which the first auxiliary heat exchanger and the second auxiliary heat exchanger are arranged, and a partition section that separates the outdoor main air duct section from the outdoor auxiliary air duct section and has a plurality of through-holes formed therein through which gas and liquid can pass.

[0008] Furthermore, the auxiliary fan of the air conditioner may be provided in the outdoor unit, for example.

[0009] Furthermore, the air conditioner may further include, for example, a heat generating mechanism capable of heating the refrigerant flowing through the third pipe.

[0010] Furthermore, the heat generating mechanism of the air conditioner may be formed of, for example, a thermoelectric element.

[0011] Furthermore, the air conditioner may further include, for example, an on-off valve in the fourth pipe.

[0012] Furthermore, the circulation air duct piping of the air conditioner may be provided with, for example, a ventilation valve that can close the circulation air duct piping.

[0013] According to the air conditioner described above, it is possible to provide an air conditioner that can smoothly provide a comfortable feeling (for example, a cooling feeling with less dampness) while suppressing an increase in the required capacity during cooling operation. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a refrigerant system diagram of an air conditioner according to an embodiment, and is also an exemplary and schematic diagram showing the flow of refrigerant during cooling operation. [Figure 2] FIG. 2 is a refrigerant system diagram of the air conditioner according to the embodiment, and is also an exemplary schematic diagram showing the flow of refrigerant during heating operation. [Figure 3] FIG. 3 is an exemplary schematic cross-sectional view showing the positions of the intake and exhaust ports of the circulation air duct pipe in the indoor unit of the air conditioner according to the embodiment. [Figure 4] FIG. 4 is an exemplary schematic explanatory diagram showing the flow of circulating air between the indoor unit and the outdoor unit during cooling operation of the air conditioner according to the embodiment. [Figure 5]FIG. 5 is an exemplary schematic explanatory diagram showing the configuration of the outdoor unit of the air conditioner according to the embodiment, the flow of air in the outdoor auxiliary air duct section, and the supply state of condensed water supplied to the outdoor main air duct section. [Figure 6] FIG. 6 is an exemplary schematic explanatory diagram showing the flow of air in the outdoor auxiliary air duct section of the outdoor unit during cooling operation of the air conditioner according to the embodiment. [Figure 7] FIG. 7 is an exemplary schematic plan view showing an aspect of a partition wall included in the outdoor unit of the air conditioner according to the embodiment. [Figure 8] FIG. 8 is an exemplary schematic explanatory diagram showing the configuration of the outdoor unit of the air conditioner according to the embodiment, the flow of air in the outdoor auxiliary air duct section, and the flow of hot air supplied to the outdoor main air duct section. [Figure 9] FIG. 9 is an exemplary schematic block diagram showing a control device for an air conditioner according to an embodiment and a configuration controlled by the control device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Several embodiments will be described below with reference to FIGS. 1 to 9. In this specification, components according to the embodiments and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0016] FIG. 1 is a refrigerant system diagram of an air conditioner according to an embodiment, and is also an exemplary and schematic diagram showing the flow of refrigerant during cooling operation. FIG. 2 is a refrigerant system diagram of an air conditioner according to an embodiment, and is also an exemplary and schematic diagram showing the flow of refrigerant during heating operation. The air conditioner 10 is, for example, a home air conditioner. However, the air conditioner 10 is not limited to this example and may be another air conditioner, such as a commercial air conditioner.

[0017] 1 and 2, an air conditioning apparatus 10 has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is disposed outdoors, for example. The indoor unit 12 is disposed indoors, for example.

[0018] The air conditioner 10 includes a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. A refrigerant flows between the outdoor unit 11 and the indoor unit 12 through the refrigerant piping 13. The outdoor unit 11 and the indoor unit 12 are also electrically connected to each other by, for example, electrical wiring.

[0019] The outdoor unit 11 has a refrigerant piping 13, an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, an expansion valve 26, a first flow control valve 27, a second flow control valve 28, a first auxiliary heat exchanger 29, a second auxiliary heat exchanger 30, a heat generation mechanism 31, and a circulation air duct piping 32.

[0020] The indoor unit 12 has an indoor heat exchanger 41, an indoor blower fan 42, and a circulation air duct 32. That is, the circulation air duct 32 is an air duct piping that is arranged across the outdoor unit 11 and the indoor unit 12.

[0021] The refrigerant pipes 13 are pipes made of metal such as copper or aluminum, and include a first pipe 51, a second pipe 52, a third pipe 53, a fourth pipe 54, and so on.

[0022] The first piping 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. The compressor 23, the accumulator 24, and the four-way valve 25 are provided in the first piping 51. The first piping 51 has a first region 51a, a second region 51b, a third region 51c, and a fourth region 51d. The first region 51a is a piping region that connects the four-way valve 25 and the indoor heat exchanger 41. The second region 51b is a piping region that connects the four-way valve 25 and the accumulator 24. The third region 51c is a piping region that connects the discharge port 23b of the compressor 23 and the four-way valve 25. The fourth region 51d is a piping region that connects the four-way valve 25 and the outdoor heat exchanger 21.

[0023] The second piping 52 connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The expansion valve 26 is provided in the second piping 52. The second piping 52 has a fifth region 52a and a sixth region 52b. The fifth region 52a is a piping region that connects the outdoor heat exchanger 21 and the expansion valve 26. The sixth region 52b is a piping region that connects the expansion valve 26 and the indoor heat exchanger 41.

[0024] The third piping 53 connects the first piping 51 (second region 51b) between the four-way valve 25 and the accumulator 24 (suction port 23a of the compressor 23) with the second piping 52 (sixth region 52b) between the expansion valve 26 and the indoor heat exchanger 41. The first auxiliary heat exchanger 29, the second flow control valve 28, and the heat generation mechanism 31 are provided in the third piping 53. The third piping 53 has a seventh region 53a, an eighth region 53b, a ninth region 53c, and a tenth region 53d. The seventh region 53a is a piping region that connects the second piping 52 (sixth region 52b) and the heat generation mechanism 31. The eighth region 53b is a piping region that connects the heat generation mechanism 31 and the second flow control valve 28. The ninth region 53c is a piping region that connects the second flow control valve 28 and the first auxiliary heat exchanger 29. The tenth region 53d is a piping region that connects the first auxiliary heat exchanger 29 and the first piping 51 (the second region 51b).

[0025] The fourth piping 54 connects the first piping 51 (fourth region 51d) between the four-way valve 25 and the outdoor heat exchanger 21 and the second piping 52 (fifth region 52a) between the expansion valve 26 and the outdoor heat exchanger 21. The second auxiliary heat exchanger 30 and the first flow control valve 27 are provided in the fourth piping 54. The fourth piping 54 has an eleventh region 54a, a twelfth region 54b, and a thirteenth region 54c. The eleventh region 54a is a piping region that connects the first piping 51 (fourth region 51d) and the second auxiliary heat exchanger 30. The twelfth region 54b is a piping region that connects the second auxiliary heat exchanger 30 and the first flow control valve 27. The thirteenth region 54c is a piping region that connects the first flow control valve 27 and the second piping 52 (the fifth region 52a).

[0026] As shown in Fig. 1, in cooling operation, the refrigerant flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the first pipe 51, and flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the second pipe 52. In addition, as shown in Fig. 2, in heating operation, the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the first pipe 51, and flows to the outdoor heat exchanger 21 through the second pipe 52.

[0027] The outdoor heat exchanger 21 of the outdoor unit 11 acts as a condenser to release heat from the refrigerant or as an evaporator to absorb heat from the refrigerant, depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air to the outdoor heat exchanger 21, promoting heat exchange between the refrigerant and air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the outdoor heat exchanger 21.

[0028] Compressor 23 has suction port 23a and discharge port 23b. Compressor 23 draws in refrigerant through suction port 23a and discharges the compressed refrigerant through discharge port 23b. In this way, compressor 23 compresses the refrigerant in a refrigeration cycle and causes the refrigerant to circulate.

[0029] The accumulator 24 is connected to the suction port 23a of the compressor 23. The accumulator 24 separates the gaseous refrigerant from the liquid refrigerant. This allows the compressor 23 to draw the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can also function as the suction port of the compressor 23 by being configured integrally with the compressor 23.

[0030] Four-way valve 25 is connected to outdoor heat exchanger 21, accumulator 24 (on the side of suction port 23a of compressor 23), indoor heat exchanger 41, and discharge port 23b of compressor 23. Four-way valve 25 switches the flow paths connected to outdoor heat exchanger 21, accumulator 24, indoor heat exchanger 41, and discharge port 23b of compressor 23 between cooling operation and heating operation, thereby changing the direction in which the refrigerant flows.

[0031] During cooling operation, the four-way valve 25 connects the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21 and supplies high-temperature, high-pressure gaseous refrigerant to the outdoor heat exchanger 21. Furthermore, during cooling operation, the four-way valve 25 connects the indoor heat exchanger 41 to the accumulator 24 and returns the low-temperature, low-pressure, almost gaseous refrigerant to the accumulator 24. As a result, the refrigerant compressed by the compressor 23 flows to the outdoor heat exchanger 21, and the refrigerant that has undergone heat exchange (condensation) in the outdoor heat exchanger 21 flows to the indoor heat exchanger 41. Then, the refrigerant that has undergone heat exchange (evaporation) in the indoor heat exchanger 41 flows to the accumulator 24.

[0032] 2, during heating operation, the four-way valve 25 connects the discharge port 23b of the compressor 23 to the indoor heat exchanger 41 and supplies high-temperature, high-pressure gaseous refrigerant to the indoor heat exchanger 41. During heating operation, the four-way valve 25 connects the outdoor heat exchanger 21 to the accumulator 24 and supplies low-temperature, low-pressure, almost gaseous refrigerant to the accumulator 24. As a result, the refrigerant compressed by the compressor 23 flows to the indoor heat exchanger 41, and the refrigerant that has undergone heat exchange (evaporated) in the indoor heat exchanger 41 flows to the outdoor heat exchanger 21. Then, the refrigerant that has undergone heat exchange (evaporated) in the outdoor heat exchanger 21 flows to the accumulator 24.

[0033] The expansion valve 26 is, for example, an electromagnetic expansion valve. However, other types of expansion valves may be used as the expansion valve 26. The opening of the expansion valve 26 is controlled to adjust the amount of refrigerant passing through, thereby determining the amount of expansion of the refrigerant and adjusting the decrease in the refrigerant temperature.

[0034] As described above, the first flow control valve 27 is provided on the fourth pipe 54. During cooling operation, the first flow control valve 27 controls the opening state to adjust the amount of refrigerant flowing into the second auxiliary heat exchanger 30, which functions as a condenser. As will be described later, air drawn into the room where the indoor unit 12 is installed passes through the circulation air duct pipe 32, passing through the first auxiliary heat exchanger 29 and then the second auxiliary heat exchanger 30, exchanging heat therebetween, and is then returned to the room. By adjusting the amount of high-temperature refrigerant flowing from the compressor 23 side into the second auxiliary heat exchanger 30, the temperature of the air returned to the room via the circulation air duct pipe 32 is heated to a temperature equal to or lower than the room temperature. On the other hand, during heating operation, the first flow control valve 27 is basically controlled to a fully closed state, stopping the flow of refrigerant through the second auxiliary heat exchanger 30 (fourth pipe 54). In other words, the heat exchange function of the second auxiliary heat exchanger 30 is stopped. The first flow control valve 27 may be any other type of electromagnetic valve that can adjust the flow rate. The first flow control valve 27 may also be an on-off valve that switches between an open state and a closed state.

[0035] As described above, the second flow control valve 28 is provided in the third piping 53 between the first auxiliary heat exchanger 29 and the heat generation mechanism 31. During cooling operation, the second flow control valve 28 controls the opening state of the valve to control the amount of refrigerant flowing into the first auxiliary heat exchanger 29, thereby adjusting the amount of low-temperature refrigerant flowing through the first auxiliary heat exchanger 29, which functions as an evaporator. The first auxiliary heat exchanger 29 then exchanges heat with air (room air W) supplied from the room via the circulation air duct 32, causing condensation (water) to form on the surface of the first auxiliary heat exchanger 29, thereby reducing the humidity of the supplied air. In other words, the room air W is dehumidified. During heating operation, the second flow control valve 28 is basically controlled to a fully open state, and gaseous refrigerant supplied from the indoor heat exchanger 41 and heated by the heat generation mechanism 31 is supplied to the first auxiliary heat exchanger 29.

[0036] The first auxiliary heat exchanger 29 and the second auxiliary heat exchanger 30 are arranged inside the outdoor unit 11 so that the indoor air W passes through the first auxiliary heat exchanger 29 and then the second auxiliary heat exchanger 30 in the circulation air duct 32 that supplies the air (indoor air W) taken in the room where the indoor unit 12 is installed to the outdoor unit 11.

[0037] As described above, the first auxiliary heat exchanger 29 functions as an evaporator during cooling operation. The first auxiliary heat exchanger 29 cools the indoor air W by exchanging heat with air (indoor air W) sent from the indoor side to the outdoor unit 11 side via the circulation air duct 32. During this process, condensation occurs on the surface of the first auxiliary heat exchanger 29, dehumidifying the indoor air W. The condensed water generated on the first auxiliary heat exchanger 29 can be supplied to the outdoor heat exchanger 21 side and can be used primarily to clean the outdoor heat exchanger 21. On the other hand, during heating operation, the first auxiliary heat exchanger 29 functions as a condenser. The first auxiliary heat exchanger 29 exchanges heat with the indoor air W sent to the outdoor unit 11 side via the circulation air duct 32, thereby raising the temperature of the indoor air W. The heated indoor air W can be supplied to the outdoor heat exchanger 21 side and can raise the temperature of the air surrounding the outdoor heat exchanger 21. As a result, it is possible to contribute to suppressing freezing or defrosting of the outdoor heat exchanger 21 during heating operation.

[0038] As described above, the second auxiliary heat exchanger 30 functions as a condenser during cooling operation. The second auxiliary heat exchanger 30 heats the indoor air W by exchanging heat with the indoor air W that has been sent to the outdoor unit 11 via the circulation air duct 32 and cooled by the first auxiliary heat exchanger 29. In this case, the indoor air W is heated to, for example, the temperature at which it was drawn into the circulation air duct 32 on the indoor side or a temperature lower than that temperature. The heated indoor air W is returned to the indoor side via the circulation air duct 32. On the other hand, during heating operation, the second auxiliary heat exchanger 30 stops functioning when the first flow control valve 27 is closed, stopping the flow of refrigerant. At this time, the circulation air duct 32 is closed downstream of the first auxiliary heat exchanger 29, causing the indoor air W heated by the first auxiliary heat exchanger 29 to stagnate on the outdoor unit 11 side or to be supplied to the outdoor heat exchanger 21 side. As a result, as described above, the heated indoor air W can raise the temperature of the air surrounding the outdoor heat exchanger 21, which can contribute to preventing freezing or defrosting of the outdoor heat exchanger 21 during heating operation.

[0039] The heat generating mechanism 31 can be configured with, for example, a heater element. The heat generating mechanism 31 mainly raises the temperature of the refrigerant supplied to the first auxiliary heat exchanger 29, which functions as a condenser during heating operation, and promotes the gasification of the refrigerant. The gaseous refrigerant with the increased temperature is then used to effectively raise the temperature of the indoor air W supplied via the circulation air duct 32, as described above, and the indoor air W improves the efficiency of freezing prevention or defrosting of the outdoor heat exchanger 21.

[0040] In another embodiment, the heat generating mechanism 31 may be configured with a thermoelectric element such as a Peltier element. A Peltier element is an energy conversion element that utilizes the interaction between heat and electricity. A Peltier element is, for example, a sheet-like element formed by joining two different types of metals or semiconductors at two points. When an electric current flows through this element, heat is also transported as the current flows from one contact to the other, heating one contact and cooling the other contact. For example, the Peltier element serving as the heat generating mechanism 31 and the third pipe 53 are arranged so that they are thermally connected to each other. The direction of the electric current flowing through the Peltier element can be controlled so that the surface of the Peltier element facing the third pipe 53 becomes the heating surface, thereby heating the refrigerant flowing through the third pipe 53. As a result, as described above, the refrigerant can be heated by the circulation air duct pipe 32. In other words, the temperature of the refrigerant can be adjusted and vaporized, contributing to the prevention of freezing or defrosting of the outdoor heat exchanger 21. Furthermore, by controlling the direction of the current flowing through the Peltier element so that the surface facing the third pipe 53 becomes the cooling surface, it is possible to cool the refrigerant flowing through the third pipe 53. In this case, for example, it is possible to supplement the cooling effect of the liquid refrigerant supplied to the first auxiliary heat exchanger 29 during cooling operation, and the first auxiliary heat exchanger 29 can dehumidify the indoor air W more efficiently.

[0041] When dehumidification is performed by heat exchange in the first auxiliary heat exchanger 29, the amount of condensation water generated, i.e., the amount of dehumidification of the indoor air W, varies depending on the humidity and temperature of the indoor air W. In this case, the heat exchange efficiency can be adjusted by controlling the amount of refrigerant supplied to the first auxiliary heat exchanger 29 through the control of the second flow control valve 28. As a result, the amount of condensation water generated, i.e., the amount of dehumidification of the indoor air W, can be adjusted. Similarly, when the heat generating mechanism 31 is composed of a Peltier element, the temperature of the refrigerant can be adjusted by controlling the Peltier element, and the heat exchange efficiency can be adjusted. As a result, the amount of condensation water generated, i.e., the amount of dehumidification of the indoor air W, can be adjusted.

[0042] The circulation air duct 32 is a duct made of metal, resin, or the like. The circulation air duct 32 is a duct that guides air (room air W) taken in a room where the indoor unit 12 is installed to the outdoor unit 11 side, passes the air through the first auxiliary heat exchanger 29 and the second auxiliary heat exchanger 30 in that order, and then guides the air to the indoor unit 12 side and returns the air to the room. The circulation air duct 32 is provided with a circulation fan 33 for flowing (circulating) the room air W through the circulation air duct 32, and a circulation shutter 34 that functions as an air vent valve that allows or blocks the flow of the room air W in the circulation air duct 32. The circulation fan 33 and the circulation shutter 34 will be described in detail below.

[0043] Fig. 3 is an exemplary schematic cross-sectional view showing the positions of the intake port 15 and the exhaust port 16 of the circulation air duct 32 in the indoor unit 12 of the air conditioner 10 according to this embodiment. Fig. 4 is an exemplary schematic explanatory diagram showing the flow of circulating air (room air W) between the indoor unit 12 and the outdoor unit 11 during cooling operation of the air conditioner 10.

[0044] The intake port 15 of the circulation air duct 32 opens, for example, in a part of the exterior panel 12a of the indoor unit 12, on the right side in the case of FIG. 3, and can take in indoor air W. Furthermore, an exhaust port 16, through which the indoor air W that has passed through the outdoor unit 11 side is exhausted, opens in a part of the exterior panel 12a, approximately in the center in the case of FIG. 3. As shown in FIGS. 1 and 4, a circulation fan 33 is disposed in a part of the flow path of the circulation air duct 32. As shown in FIG. 4, when the circulation fan 33 is driven, an airflow is generated in the circulation air duct 32, and air from the room R in which the indoor unit 12 is installed is drawn in through the intake port 15. The indoor air W1 drawn in through the intake port 15 is cooled and dehumidified by the first auxiliary heat exchanger 29 as it passes through the outdoor unit 11 as indoor air W2. In addition, while passing through the second auxiliary heat exchanger 30, the air is heated to a temperature equal to or lower than the temperature of the air in room R, and is returned to the indoor unit 12 as indoor air W3 and discharged into room R from the exhaust port 16.

[0045] During heating operation of the air conditioner 10, the circulation air duct 32 is closed by closing the circulation shutter 34, and the circulation fan 33 is stopped or operated at a low speed. As a result, the indoor air W2 remains in the circulation air duct 32 and is heated by the first auxiliary heat exchanger 29. The heated indoor air W2 is drawn in by the airflow generated by the outdoor blower fan 22 and moves toward the outdoor heat exchanger 21, thereby contributing to preventing freezing or defrosting of the outdoor heat exchanger 21. The installation positions of the air inlet 15 and the exhaust outlet 16 can be selected appropriately. For example, the air inlet 15 and the exhaust outlet 16 may be installed in close proximity to each other or in separate locations. When installed in separate locations, the air inlet 15 and the exhaust outlet 16 may be installed in the locations shown in FIG. 3 , near the left and right ends of the exterior panel 12a, on the left and right sides, or on the top and bottom surfaces of the indoor unit 12, for example. When the intake port 15 and the exhaust port 16 are installed at positions separated from each other, the mixing of the high-humidity indoor air W that is sucked in and the low-humidity indoor air W that is exhausted is reduced, and the high-humidity indoor air W and the low-humidity indoor air W can be efficiently exchanged in the room.

[0046] In this way, when the air conditioner 10 is operating in cooling mode, the air conditioner 10 temporarily transfers the air in room R to the outdoor unit 11 side, dehumidifies it, and then returns it to room R. The indoor unit 12 installed in room R, separate from the flow of indoor air W circulating through the circulation air duct 32, draws in dehumidified indoor air W by driving the indoor blower fan 42 and exchanges heat in the indoor heat exchanger 41, thereby discharging cool air (indoor air W4) from the air outlet 12b to room R, thereby cooling room R. Note that by locating the exhaust outlet 16 near the intake port that draws in the indoor air W when the indoor blower fan 42 is driven, it is possible to efficiently take in dehumidified indoor air W3 and efficiently generate cool air through heat exchange in the indoor heat exchanger 41.

[0047] The circulation fan 33 can have any structure as long as it can move the indoor air W from the air inlet 15 to the air outlet 16 of the circulation air duct 32. For example, it can be configured as an axial fan. The installation position of the circulation fan 33 in the circulation air duct 32 can be selected as appropriate as long as it can move the indoor air W from the air inlet 15 to the air outlet 16. For example, it is desirable to install the circulation fan 33 on the outdoor unit 11 side. By installing the circulation fan 33 in the circulation air duct 32 on the outdoor unit 11 side, the driving noise of the circulation fan 33 can be made less noticeable indoors. This contributes to improving quietness indoors when the air conditioner 10 is operating. Furthermore, placing the circulation fan 33 on the outdoor unit 11 side can also contribute to reducing the size of the indoor unit 12.

[0048] Fig. 5 is an exemplary and schematic explanatory diagram showing the configuration of the outdoor unit 11 of the air conditioner 10 according to this embodiment, the flow of air in the outdoor auxiliary air duct section, and the supply status of condensation water supplied to the outdoor main air duct section. Fig. 5 is a diagram showing the state of the air conditioner 10 (outdoor unit 11) during cooling operation.

[0049] As shown in FIG. 5, the outdoor unit 11 of the air conditioner 10 of this embodiment includes an outdoor main air duct section 11M and an outdoor auxiliary air duct section 11S arranged above the outdoor main air duct section 11M.

[0050] The outdoor main air passage 11M is an air passage formed in a space open to the outside air for flowing air (air around the outdoor unit 11) to an area including the outdoor heat exchanger 21, the outdoor blower fan 22, etc. Specifically, the outdoor main air passage 11M forms an air passage that passes the outside air taken in by driving the outdoor blower fan 22 through the outdoor heat exchanger 21, which performs heat exchange, and then discharges it outside the outdoor unit 11 again.

[0051] On the other hand, the outdoor auxiliary air duct section 11S includes a first auxiliary heat exchanger 29, a second auxiliary heat exchanger 30, a circulation fan 33, etc., and is an air duct formed in a substantially closed space surrounded by walls for circulating the indoor air W supplied by the circulation air duct piping 32. The outdoor auxiliary air duct section 11S is formed with a discharge port 32m that discharges the indoor air W circulated by the circulation air duct piping 32 into the outdoor auxiliary air duct section 11S, and a recovery port 32n that recovers the indoor air W that has been discharged into the outdoor auxiliary air duct section 11S and subjected to heat exchange. The discharge port 32m is a funnel-shaped opening with an enlarged open end that is formed on the other end of the suction piping area 32a (circulation air duct piping 32) that communicates with the suction port 15 (see FIG. 3) of the indoor unit 12, and is located on the side of the outdoor auxiliary air duct section 11S where the first auxiliary heat exchanger 29 is located (upstream of the flow of the indoor air W). In addition, the recovery port 32n is a funnel-shaped opening with an enlarged open end formed on the other end side of the exhaust piping area 32b (circulation air duct 32) that communicates with the exhaust port 16 (see Figure 3) of the indoor unit 12, and is located on the side of the outdoor auxiliary air duct section 11S where the second auxiliary heat exchanger 30 is located (downstream of the flow of indoor air W).

[0052] FIG. 6 is an exemplary schematic explanatory diagram showing the flow of air (room air W) in the outdoor auxiliary air duct portion 11S of the outdoor unit 11 during cooling operation of the air conditioner 10 according to the embodiment.

[0053] By driving the circulation fan 33 (not shown in FIG. 6), indoor air W1 (W) from the room R (see FIG. 4) is drawn in through the air inlet 15 and then passes through the circulation air duct 32 (the air inlet duct region 32a) and is then discharged from the air outlet 32m toward the first auxiliary heat exchanger 29 disposed in the outdoor auxiliary air duct section 11S. At this time, the funnel-shaped air outlet 32m (see FIG. 5), which expands in diameter toward the first auxiliary heat exchanger 29, allows the indoor air W1 to be supplied to a wide area of ​​the first auxiliary heat exchanger 29, which performs cooling and dehumidification. As a result, efficient heat exchange between the indoor air W (W2a) and the first auxiliary heat exchanger 29 is achieved. Similarly, the funnel-shaped recovery port 32n (see FIG. 5), which expands in diameter toward the second auxiliary heat exchanger 30, allows the heated indoor air W (W2b) to be recovered from a wide area of ​​the second auxiliary heat exchanger 30. As a result, the recovered indoor air W (W3) can be efficiently sent to the exhaust piping area 32b (circulation air duct 32) and returned to the indoor unit 12 side.

[0054] While FIG. 5 illustrates the discharge port 32m and the recovery port 32n having a funnel-like shape with an expanded diameter at the open end, this shape is merely an example, and any shape may be used as long as it allows the supply of room air W1 to the outdoor auxiliary air duct section 11S and the recovery of room air W2 from the outdoor auxiliary air duct section 11S. For example, the funnel-like portion may be formed with a curved or stepped surface. Furthermore, the discharge port 32m and the recovery port 32n may be formed as straight pipes with a larger diameter than the circulation air duct piping 32. Furthermore, the shape of the discharge port 32m and the recovery port 32n may be formed as the discharge port 32m and the recovery port 32n without expanding the diameter of the end of the circulation air duct piping 32, as long as it allows for smooth supply of room air W1 and smooth recovery of room air W2.

[0055] As described above, when the air conditioner 10 is operating in cooling mode, if the humidity of the indoor air W in the room R is high, it may take some time for the room R to achieve the comfortable environment expected by the user. Therefore, in the air conditioner 10 of this embodiment, the outdoor unit 11 dehumidifies the indoor air W in parallel with the cooling mode. Specifically, the indoor air W is sent to the outdoor auxiliary air duct section 11S via the circulation air duct 32, where heat exchange occurs between the outdoor air W and the first auxiliary heat exchanger 29, which functions as an evaporator. The moisture contained in the indoor air W passing through the first auxiliary heat exchanger 29, through which a low-temperature refrigerant flows, condenses on the surface of the first auxiliary heat exchanger 29 through which the low-temperature refrigerant flows. As a result, the indoor air W is dehumidified. The condensed water formed on the surface of the first auxiliary heat exchanger 29 falls onto the partition wall 35 that forms the bottom surface of the outdoor auxiliary air duct section 11S due to gravity, the wind force of the indoor air W2 flowing through the outdoor auxiliary air duct section 11S, vibrations during operation of the outdoor unit 11, and the like.

[0056] FIG. 7 is an exemplary schematic plan view showing an aspect of the partition wall portion 35 included in the outdoor unit 11 of the air conditioner 10 according to the embodiment.

[0057] The partition wall 35 is a plate-like member made of, for example, metal or resin, in which a plurality of through-holes 35a through which gas and liquid can pass are formed, separating the outdoor main air passage 11M and the outdoor auxiliary air passage 11S, and which forms the bottom surface of the outdoor auxiliary air passage 11S. In the example shown in Fig. 7, the through-holes 35a are circular holes, but the shape of the through-holes 35a can be selected appropriately as long as it allows gas and liquid to pass through and enables the passed gas and liquid to be supplied to the entire area of ​​the outdoor main air passage 11M (particularly the outdoor heat exchanger 21), and may be an elliptical shape, polygonal shape, groove shape, or the like.

[0058] As described above, during cooling operation of the air conditioner 10, the condensed water D generated when the indoor air W is dehumidified via the first auxiliary heat exchanger 29 passes through the through-hole 35a of the partition wall 35 and is supplied to the entire outdoor main air passage 11M (particularly the outdoor heat exchanger 21) as shown in FIG. 5 . The condensed water D can clean the fins and other components formed on the surface of the outdoor heat exchanger 21. As a result, it is possible to prevent a decrease in heat exchange efficiency due to contamination of the outdoor heat exchanger 21, contributing to maintaining and improving the efficiency of cooling operation. Furthermore, maintaining and improving the efficiency of cooling operation can contribute to energy conservation. Furthermore, supplying the condensed water D to the outdoor heat exchanger 21 makes it possible to lower the ambient temperature of the outdoor heat exchanger 21. As a result, even if the temperature of the gaseous refrigerant supplied to the outdoor heat exchanger 21 during cooling operation is lowered, the heat exchange of the refrigerant required for cooling operation is possible. That is, it becomes possible to lower the temperature of the refrigerant supplied from the compressor 23, thereby reducing the workload of the compressor 23. Therefore, this also contributes to energy conservation during cooling operation. The condensed water D used for cleaning the outdoor heat exchanger 21, etc., is discharged to the outside of the outdoor unit 11 via a drain pan or the like provided below the outdoor unit 11, together with the condensed water generated on the indoor unit 12 side during cooling operation.

[0059] During cooling operation, warm air flows in the outdoor main air duct 11M as a result of heat exchange in the outdoor heat exchanger 21, but is discharged, for example, to the front side of the outdoor unit 11 by driving the outdoor blower fan 22. As a result, there is little possibility that the warm air will move through the through-hole 35a toward the outdoor auxiliary air duct 11S located above the outdoor main air duct 11M. Furthermore, the flow direction of the warm air flowing due to the driving of the outdoor blower fan 22 differs from the flow direction of the indoor air W in the outdoor auxiliary air duct 11S, and they function as a so-called air curtain, suppressing the mixing of air of different temperatures. Therefore, it can be assumed that the warm air generated by heat exchange in the outdoor heat exchanger 21 does not affect the heat exchange in the first auxiliary heat exchanger 29 or the generation of condensation water.

[0060] During cooling operation of the air conditioner 10, the indoor air W2, which has been cooled and dehumidified by heat exchange in the first auxiliary heat exchanger 29, is heated while substantially maintaining its humidity as it passes through the second auxiliary heat exchanger 30, which functions as a condenser and is located downstream of the first auxiliary heat exchanger 29. For example, the indoor air W2 is reheated to a temperature equal to or lower than the temperature in room R and returned to room R via the indoor unit 12. By reheating the dehumidified indoor air W and returning it to the temperature of room R before circulating it, accurate temperature control of room R can be easily achieved by controlling only the indoor unit 12. Furthermore, in the air conditioner 10 of this embodiment, dehumidification of the indoor air W can be performed on the outdoor unit 11 side, eliminating the need for dehumidification processing on the indoor unit 12 side, which contributes to simplifying the structure and reducing the size of the indoor unit 12.

[0061] When the air conditioner 10 is operating in heating mode, for example when the outdoor air temperature is low, the humidity of the indoor air W is not very high and dehumidification is often unnecessary. On the other hand, during heating mode, the outdoor heat exchanger 21, which functions as an evaporator, may freeze, causing the heating mode to be temporarily stopped or the heating efficiency to decrease due to defrosting. Therefore, in the case of the air conditioner 10 of this embodiment, when operating in heating mode, the first auxiliary heat exchanger 29 functions as a condenser to raise the temperature of the supplied indoor air W, which is used to prevent freezing or defrost the outdoor heat exchanger 21.

[0062] Figure 8 is an exemplary and schematic explanatory diagram showing the configuration of the outdoor unit 11 of the air conditioning apparatus 10 according to the embodiment, the flow of air (indoor air W2) in the outdoor auxiliary air duct section 11S, and the flow of warm air (indoor air W2) supplied to the outdoor main air duct section 11M.

[0063] As described above, when the air conditioner 10 is operating in a heating mode, there is little need to adjust the humidity of the indoor air W in the room R. Therefore, it is not necessary to circulate the indoor air W between the indoor unit 12 and the outdoor unit 11 via the circulation air duct 32. However, to send warm air toward the outdoor heat exchanger 21 (the outdoor main air duct 11M side) to prevent freezing or defrost the outdoor heat exchanger 21, the circulation fan 33 is driven at low speed or intermittently to appropriately send the indoor air W to the outdoor auxiliary air duct 11S. In this case, the circulation shutter 34 (ventilation valve) provided in the discharge duct region 32b of the circulation air duct 32 is closed to prevent the indoor air W2, whose temperature has increased due to heat exchange with the first auxiliary heat exchanger 29, from flowing toward the indoor unit 12. As a result, the heated indoor air W2 is pushed toward the outdoor main air duct 11M through the through-hole 35a of the partition wall 35 in the outdoor auxiliary air duct 11S. As a result, the temperature of the air in the outdoor main air passage portion 11M is increased, and freezing of the outdoor heat exchanger 21 can be suppressed or defrosted.

[0064] In this case, the circulation fan 33 may be stopped. In this case, air heated by heat exchange with the first auxiliary heat exchanger 29 stagnates in the outdoor auxiliary air duct 11S. At this time, outside air flows in the outdoor main air duct 11M, for example, from the rear side to the front side of the outdoor unit 11, due to the operation of the outdoor blower fan 22. This flow of outside air causes the heated air stagnate in the outdoor auxiliary air duct 11S to be drawn into the outdoor main air duct 11M and supplied to the outdoor heat exchanger 21. In other words, even when the circulation fan 33 is stopped, the indoor air W2 is drawn from the indoor unit 12 side through the circulation air duct piping 32. Then, as when the circulation fan 33 is driven, the heated indoor air W2 can suppress freezing or defrost the outdoor heat exchanger 21.

[0065] The need for freeze suppression or defrosting of the outdoor heat exchanger 21 can be determined, for example, based on the outdoor air temperature and the temperature of the outdoor heat exchanger 21. The temperature of the refrigerant supplied to the first auxiliary heat exchanger 29 can be adjusted according to the outdoor air temperature and the temperature of the outdoor heat exchanger 21 to control the heating temperature of the indoor air W2 used for freeze suppression and defrosting. In this case, the temperature of the refrigerant supplied to the first auxiliary heat exchanger 29 can be controlled by adjusting the heat generation temperature in the heat generation mechanism 31 or by controlling the flow rate of the second flow control valve 28. In this way, the air conditioning apparatus 10 of this embodiment can prevent freeze and defrost the outdoor heat exchanger 21 during heating operation using the first auxiliary heat exchanger 29, thereby simplifying control (eliminating the need for a defrosting function).

[0066] The circulation shutter 34 may be any mechanism capable of opening and closing the air passage of the circulation air passage piping 32, and may be, for example, a solenoid valve. If defrosting operation is not used (if the defrosting function of the air conditioner 10 is omitted), the circulation shutter 34 may be omitted from the configuration.

[0067] The control device 14 controls the outdoor blower fan 22, indoor blower fan 42, circulation fan 33, circulation shutter 34, compressor 23, heat generating mechanism 31, and various valves provided in the outdoor unit 11 and the indoor unit 12, and performs cooling operation, heating operation, and other operational control. The control device 14 is composed of, for example, an outdoor control device 14a provided in the outdoor unit 11 and an indoor control device 14b provided in the indoor unit 12. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other and send and receive control signals to 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, for example, a signal input from a remote controller operated by the user, or by a signal input from an information terminal such as a smartphone via a communication device. The outdoor control device 14a and the indoor control device 14b may be combined into a single control device 14. In this case, the control device 14 may be provided in either the outdoor unit 11 or the indoor unit 12, but can be provided in the indoor unit 12, for example.

[0068] The control device 14 is, for example, a computer having a control device such as a CPU (Central Processing Unit) or a microcontroller, and a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. However, the control device 14 is not limited to this example.

[0069] Figure 9 is an exemplary schematic block diagram showing the control device 14 of the air conditioner 10 of this embodiment and the configuration controlled by the control device 14. As shown in Figure 9, the air conditioner 10 of this embodiment has an outdoor fan drive circuit 80, an indoor fan drive circuit 81, an inverter circuit 82, a four-way valve drive circuit 83, an expansion valve drive circuit 84, a first flow control valve drive circuit 85, a second flow control valve drive circuit 86, a circulation fan drive circuit 87, a circulation shutter drive circuit 88, an element drive circuit 89, and the like.

[0070] The outdoor fan drive circuit 80 is a drive circuit for the outdoor blower fan 22. The indoor fan drive circuit 81 is a drive circuit for the indoor blower fan 42. The inverter circuit 82 inverter-controls the compressor 23 to change the frequency of the compressor 23. The inverter circuit 82 is, for example, a PAM (Pulse Amplitude Modulation) type inverter circuit. However, the inverter circuit 82 is not limited to this example.

[0071] The four-way valve drive circuit 83 is a drive circuit for the four-way valve 25. The expansion valve drive circuit 84 is a drive circuit for the expansion valve 26. The first flow control valve drive circuit 85 is a drive circuit for the first flow control valve 27. The second flow control valve drive circuit 86 is a drive circuit for the second flow control valve 28. The circulation fan drive circuit 87 is a drive circuit for the circulation fan 33. The circulation shutter drive circuit 88 is a drive circuit for the circulation shutter 34. The element drive circuit 89 is a control circuit for the elements that make up the heat generation mechanism 31.

[0072] The control device 14 is connected to the humidity sensors H1, H2, the temperature sensors T1 to T7, the temperature sensor Su, the outdoor fan drive circuit 80, the indoor fan drive circuit 81, the inverter circuit 82, the four-way valve drive circuit 83, the expansion valve drive circuit 84, the first flow control valve drive circuit 85, the second flow control valve drive circuit 86, the circulation fan drive circuit 87, the circulation shutter drive circuit 88, and the element drive circuit 89. The control device 14 includes a humidity acquisition unit 90, 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, a circulation fan control unit 97, a circulation shutter control unit 98, and a temperature control unit 99.

[0073] The humidity acquisition unit 90 uses humidity sensors H1 and H2 to detect the humidity of the indoor air W1 in the room R (see FIG. 4) that is drawn into the circulation air duct 32 and the humidity of the indoor air W3 that is discharged from the circulation air duct 32. The humidity sensor H1 is installed, for example, near the air inlet 15 formed in the indoor unit 12, and detects the humidity of the indoor air W1 before dehumidification that is drawn into the circulation air duct 32. The humidity sensor H2 is installed near the air outlet 16 formed in the indoor unit 12, and detects the humidity of the dehumidified indoor air W3 that is discharged from the circulation air duct 32. The detected (acquired) humidity can be used to control the temperature and supply amount of refrigerant supplied to the first auxiliary heat exchanger 29 and the second auxiliary heat exchanger 30.

[0074] The temperature acquisition unit 91 measures the temperatures of various parts of the refrigeration cycle using temperature sensors T1 to T7 and temperature sensor Su. As shown in FIGS. 1 and 2, for example, temperature sensor T1 detects the temperature (T1 value) of the refrigerant inside the indoor heat exchanger 41. Temperature sensor T2 detects the temperature (T2 value) of the refrigerant inside the outdoor heat exchanger 21. Temperature sensor T3 detects the temperature (T3 value) of the refrigerant inside the first auxiliary heat exchanger 29. Temperature sensor T4 detects the temperature (T4 value) of the refrigerant inside the second auxiliary heat exchanger 30. Temperature sensor T5 is installed around the air inlet 15 formed in the indoor unit 12 and detects the temperature (T5 value) of the undehumidified indoor air W1 drawn into the circulation air duct 32. Temperature sensor T6 is installed around the air outlet 16 formed in the indoor unit 12 and detects the temperature (T6 value) of the dehumidified indoor air W3 discharged from the circulation air duct 32. Temperature sensor T7 detects the temperature (T7 value) of the refrigerant inside heat generating mechanism 31. Temperature sensor Su detects the temperature (Su value) of the refrigerant at the refrigerant inlet of accumulator 24. Note that humidity sensors and temperature sensors are not limited to the humidity sensors H1, H2, temperature sensors T1 to T7, and temperature sensor Su described above, but may be provided in various locations in outdoor unit 11 and indoor unit 12, and the detection results may be used to control the air conditioner 10.

[0075] The operation switching unit 92 switches the air conditioner 10 between cooling operation, heating operation, and other operations.

[0076] The outdoor fan control unit 93 controls the outdoor blower fan 22. For example, the outdoor fan control unit 93 controls the outdoor fan drive circuit 80 to control the rotation speed of the motor of the outdoor blower fan 22.

[0077] The indoor fan control unit 94 controls the indoor blower fan 42. For example, the indoor fan control unit 94 controls the indoor fan drive circuit 81 to control the rotation speed of the motor of the indoor blower fan 42, and thereby controls the wind speed and air volume of the air (room air W4) blown out from the indoor unit 12.

[0078] The compressor control unit 95 controls the compressor 23. For example, the compressor control unit 95 controls the inverter circuit 82 to control the frequency (operating frequency) of the compressor 23 through inverter control.

[0079] The valve control unit 96 controls the four-way valve 25, the expansion valve 26, the first flow control valve 27, and the second flow control valve 28. The valve control unit 96 controls the four-way valve drive circuit 83 to drive the actuator of the four-way valve 25 and change the direction of refrigerant flow in the four-way valve 25. The valve control unit 96 controls the expansion valve drive circuit 84 to drive the actuator of the expansion valve 26 and control the amount of refrigerant flowing (expansion amount) in the expansion valve 26. The valve control unit 96 controls the first flow control valve drive circuit 85 and the second flow control valve drive circuit 86 to change the opening degrees of the first flow control valve 27 and the second flow control valve 28, thereby adjusting the flow rate of the medium.

[0080] The circulation fan control unit 97 controls the circulation fan 33. For example, the circulation fan control unit 97 controls the circulation fan drive circuit 87 to control the rotation speed of the motor of the circulation fan 33, and thereby controls the amount of circulation (circulation speed) of the room air W in the circulation air duct 32.

[0081] The circulation shutter control unit 98 controls the circulation shutter 34. For example, the circulation shutter control unit 98 controls the circulation shutter drive circuit 88 to drive the actuator of the circulation shutter 34, and performs opening and closing control on the circulation air duct 32 (exhaust duct area 32b), thereby controlling the flow of the indoor air W in the outdoor auxiliary air duct section 11S (circulation air duct piping 32).

[0082] The temperature control unit 99 controls the heat generating mechanism 31. For example, the temperature control unit 99 controls the element drive circuit 89 to control the current flowing through the elements (for example, heater elements, Peltier elements, etc.) of the heat generating mechanism 31, thereby controlling the temperature of the refrigerant supplied to the first auxiliary heat exchanger 29. Furthermore, during heating operation, the temperature control unit 99 heats and gasifies the refrigerant flowing through the third pipe 53.

[0083] Cooling operation and heating operation of the air conditioner 10 of this embodiment configured as described above will be described.

[0084] First, cooling operation will be described based on the medium flow pattern shown in Fig. 1. For example, when the air conditioning apparatus 10 starts up and the cooling operation begins simultaneously, the outdoor blower fan 22, the circulation fan 33, the compressor 23, and the indoor blower fan 42 are stopped. In this case, the outdoor fan control unit 93, the indoor fan control unit 94, the circulation fan control unit 97, and the compressor control unit 95 start the outdoor blower fan 22, the indoor blower fan 42, the circulation fan 33, and the compressor 23 when the cooling operation begins.

[0085] During cooling operation, the outdoor fan control unit 93 adjusts the rotation speed of the outdoor blower fan 22. The indoor fan control unit 94 adjusts the rotation speed of the indoor blower fan 42. For example, the indoor fan control unit 94 controls the indoor blower fan 42 between weak wind (low speed) operation and strong wind (high speed) operation in accordance with the air temperature of the room R in which the indoor unit 12 is installed or a signal input from the remote controller. The circulation fan control unit 97 adjusts the rotation speed of the circulation fan 33 to adjust the flow rate of the indoor air W in order to control the amount of dehumidification in the circulation air duct 32. The compressor control unit 95 adjusts the frequency of the compressor 23.

[0086] When the cooling operation is started, the valve control unit 96 controls the four-way valve drive circuit 83 to change the direction of refrigerant flow in the four-way valve 25 for cooling. The valve control unit 96 also controls the expansion valve drive circuit 84, the first flow control valve drive circuit 85, the second flow control valve drive circuit 86, and the circulation shutter control unit 98 to change the open / close states of the expansion valve 26, the first flow control valve 27, the second flow control valve 28, and the circulation shutter 34 for cooling.

[0087] Specifically, the four-way valve 25 connects the first region 51a and the second region 51b of the first pipe 51 to connect the indoor heat exchanger 41 and the accumulator 24. The four-way valve 25 also connects the fourth region 51d and the third region 51c of the first pipe 51, and connects the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21. As a result, high-pressure, high-temperature gaseous refrigerant discharged from the compressor 23 is supplied to the outdoor heat exchanger 21. The outdoor heat exchanger 21 functions as a condenser and performs heat exchange of the refrigerant. As a result of the heat exchange in the outdoor heat exchanger 21, the refrigerant changes to a medium-temperature, high-pressure liquid and flows through the fifth region 52a of the second pipe 52 to the expansion valve 26. At this time, the first flow control valve 27 is controlled to be open, and a portion of the high-temperature, high-pressure gaseous refrigerant from the compressor 23 flows from the fourth region 51d to the eleventh region 54a of the fourth pipe 54 and is supplied to the second auxiliary heat exchanger 30. The second auxiliary heat exchanger 30 functions as a condenser and reheats the room air W2 that has been cooled for dehumidification, as described above (see FIG. 5). As a result of the heat exchange in the second auxiliary heat exchanger 30, the refrigerant changes to a medium-temperature, high-pressure liquid state and flows through the twelfth region 54b of the fourth pipe 54, the first flow control valve 27, the thirteenth region 54c, and the fifth region 52a of the second pipe 52 to the expansion valve 26.

[0088] The expansion valve 26 reduces the pressure of the medium-temperature, high-pressure liquid refrigerant by controlling the throttle of the valve, thereby expanding and lowering the temperature. The refrigerant that has changed to a low-temperature, low-pressure liquid state then passes through the sixth region 52b of the second pipe 52 and is supplied to the indoor heat exchanger 41. The low-temperature, low-pressure liquid refrigerant supplied to the indoor heat exchanger 41 exchanges heat with the indoor air (room air W). The air cooled by the heat exchange (see FIG. 4: room air W4) is released into the room R, thereby cooling the room R.

[0089] At this time, the second flow control valve 28 is controlled to be open, and a portion of the refrigerant that has been converted into a low-temperature, low-pressure liquid by the expansion valve 26 passes through the seventh, eighth, and ninth regions 53a, 53b, and 53c of the third piping 53 and is supplied to the first auxiliary heat exchanger 29, which functions as an evaporator. At this time, the circulation fan 33 is driven to draw indoor air W from the room R through the air inlet 15 opened to the indoor unit 12, pass through the circulation air duct 32, and be supplied to the outdoor auxiliary air duct 11S of the outdoor unit 11. If the heat generating mechanism 31 is composed of a heater element or the like, the temperature control unit 99 deactivates the heat generating mechanism 31 during cooling operation, allowing the liquid refrigerant passing through it to pass through as is. If the heat generating mechanism 31 is composed of a Peltier element or the like, the temperature control unit 99 may cool the liquid refrigerant passing through it using the cooling action of the Peltier element during cooling operation.

[0090] 5, the first auxiliary heat exchanger 29 functioning as an evaporator exchanges heat with the indoor air W2 supplied to the outdoor auxiliary air duct section 11S via the circulation air duct 32 (intake duct region 32a) to cool the indoor air W2. At this time, the first auxiliary heat exchanger 29 through which the low-temperature refrigerant flows generates condensation water on the surface of the first auxiliary heat exchanger 29. As a result, the indoor air W2 is dehumidified.

[0091] The indoor air W2 dehumidified during heat exchange with the first auxiliary heat exchanger 29 exchanges heat with the second auxiliary heat exchanger 30, which is arranged downstream of the outdoor auxiliary air duct section 11S and functions as a condenser during cooling operation as described above. In other words, the dehumidified indoor air W2 is heated, for example, to a temperature equivalent to the temperature of the room R while remaining dehumidified, and passes through the circulation air duct piping 32 (exhaust piping area 32b) and is discharged into the room R from the exhaust port 16 of the indoor unit 12.

[0092] Here, an example of a dehumidification process for indoor air W will be described. Consider a case where the temperature of indoor air W1 drawn into the circulation air duct 32 from the room R is, for example, 27°C and the humidity is, for example, 70%. In this case, the first auxiliary heat exchanger 29 cools the indoor air W2a through heat exchange to, for example, a temperature of 20°C and a humidity of 70%. At this time, the first auxiliary heat exchanger 29 dehumidifies the indoor air W2a by generating condensed water D on its surface. Subsequently, the second auxiliary heat exchanger 30, functioning as a condenser, exchanges heat with the dehumidified indoor air W2a to change it to indoor air W2b with, for example, a temperature of 27°C and a humidity of 45%. The dehumidified indoor air W3, whose temperature has been returned to approximately the same as the original room temperature, is then discharged from the discharge port 16 via the circulation air duct 32 (discharge duct region 32b).

[0093] As a result, when the indoor unit 12 performs cooling operation, the indoor air W3 that has been dehumidified on the outdoor unit 11 side and returned to a temperature equivalent to the room temperature of the room R is sucked in by the indoor blower fan 42 and supplied to the indoor heat exchanger 41, thereby performing cooling operation.

[0094] The refrigerant that has been heat exchanged and gasified in the indoor heat exchanger 41 passes through the first pipe 51, the four-way valve 25, and the accumulator 24, and returns to the compressor 23. The refrigerant that has been heat exchanged and gasified in the first auxiliary heat exchanger 29 passes through the third pipe 53 (tenth region 53d) and the first pipe 51 (second region 51b) and the accumulator 24, and returns to the compressor 23.

[0095] In this way, the air conditioner 10 of this embodiment, which controls the circulation of refrigerant during cooling operation, can dehumidify the indoor air W in the outdoor unit 11 at an early stage after cooling begins, separate from the heat exchange process in the indoor unit 12. As a result, the indoor unit 12 can smoothly perform heat (sensible heat) processing, which is likely to cause a drop in indoor temperature, using the dehumidified indoor air W3 at an early stage after cooling begins, without expending energy on water vapor processing for dehumidification. This allows the air conditioner 10 (indoor unit 12) to quickly achieve the cooling state desired by the user. In this case, condensed water D generated when the indoor air W is dehumidified via the first auxiliary heat exchanger 29 can be supplied to the outdoor heat exchanger 21, as shown in FIG. 5. The condensed water D can clean the fins and other components formed on the surface of the outdoor heat exchanger 21, thereby preventing a decrease in heat exchange efficiency due to contamination of the outdoor heat exchanger 21. This contributes to maintaining or improving the efficiency of cooling operation. In other words, this can contribute to energy conservation, etc. Furthermore, by supplying the condensed water D to the outdoor heat exchanger 21, it is possible to lower the ambient temperature of the outdoor heat exchanger 21, and even if the temperature of the gaseous refrigerant supplied to the outdoor heat exchanger 21 is lowered, the heat exchange of the refrigerant necessary for cooling operation in the outdoor heat exchanger 21 is possible. Therefore, it is possible to lower the temperature of the refrigerant supplied from the compressor 23, and the workload of the compressor 23 can be reduced. This also contributes to energy conservation during cooling operation of the air conditioner 10. Furthermore, because the indoor air W is dehumidified on the outdoor unit 11 side, it is possible to maintain sufficient cooling function even if the operating capacity of the indoor unit 12 is reduced, which can contribute to the miniaturization of the indoor unit 12 and, ultimately, the air conditioner 10.

[0096] Next, heating operation will be described based on the medium flow pattern shown in Fig. 2. In the case of heating operation, for example, if the air conditioner 10 is started and the heating operation starts simultaneously, the outdoor blower fan 22, the circulation fan 33, the compressor 23, and the indoor blower fan 42 are stopped. In this case, the outdoor fan control unit 93, the indoor fan control unit 94, the circulation fan control unit 97, and the compressor control unit 95 start the outdoor blower fan 22, the indoor blower fan 42, the circulation fan 33, and the compressor 23 when the heating operation starts.

[0097] During heating operation, the outdoor fan control unit 93 adjusts the rotation speed of the outdoor blower fan 22. The indoor fan control unit 94 adjusts the rotation speed of the indoor blower fan 42. For example, the indoor fan control unit 94 controls the indoor blower fan 42 between weak wind (low speed) operation and strong wind (high speed) operation in accordance with the air temperature of the room R in which the indoor unit 12 is installed or a signal input from the remote controller. The compressor control unit 95 adjusts the frequency of the compressor 23. The circulation fan control unit 97 adjusts the rotation speed of the circulation fan 33 as necessary to send indoor air W into the circulation air duct 32. For example, during heating operation, if it is determined that the outdoor heat exchanger 21 needs to be prevented from freezing or that defrosting is necessary based on the detection value (T2 value) of the temperature sensor T2, which indicates the outdoor air temperature or the refrigerant temperature in the outdoor heat exchanger 21, the circulation fan control unit 97 adjusts the rotation speed of the circulation fan 33 to send indoor air W to be used for freezing prevention (or defrosting) into the circulation air duct 32. Note that during heating operation, the circulation fan 33 may be constantly driven to send indoor air W that can be used for freezing prevention (or defrosting) into the circulation air duct 32. Also, as described above, the circulation fan 33 may be stopped and the suction force of the airflow generated by the outdoor blower fan 22 may be used to draw air from the outdoor auxiliary air duct section 11S, thereby moving the indoor air W that can be used for freezing prevention (or defrosting) from the indoor unit 12 side.

[0098] When the heating operation is started, the valve control unit 96 controls the four-way valve drive circuit 83 to change the direction of refrigerant flow in the four-way valve 25 for heating. The valve control unit 96 also controls the expansion valve drive circuit 84, the first flow control valve drive circuit 85, the second flow control valve drive circuit 86, and the circulation shutter control unit 98 to change the open / close valve states of the expansion valve 26, the first flow control valve 27, the second flow control valve 28, and the circulation shutter 34 for heating.

[0099] Specifically, the four-way valve 25 connects the fourth region 51d and the second region 51b of the first pipe 51 to connect the outdoor heat exchanger 21 and the accumulator 24. The four-way valve 25 also connects the third region 51c and the first region 51a of the first pipe 51 to connect the discharge port 23b of the compressor 23 and the indoor heat exchanger 41. As a result, high-temperature, high-pressure gaseous refrigerant is supplied from the compressor 23 to the indoor heat exchanger 41, and heat exchange occurs in the indoor heat exchanger 41, which functions as a condenser, to efficiently supply hot air to the room R.

[0100] The refrigerant that has been heat exchanged in the indoor heat exchanger 41 and changed into a medium-temperature, high-pressure liquid state passes through the fifth region 52a of the second pipe 52 and is supplied to the expansion valve 26. The refrigerant supplied to the expansion valve 26 then changes to a low-temperature, low-pressure state, and is then supplied to the outdoor heat exchanger 21 through the fifth region 52a. The refrigerant that has been gasified by heat exchange in the outdoor heat exchanger 21, which functions as an evaporator, passes through the first pipe 51 (fourth region 51d), and returns to the compressor 23 via the four-way valve 25 and the accumulator 24.

[0101] Furthermore, a portion of the refrigerant that has been heat exchanged in the indoor heat exchanger 41 and changed into a medium-temperature, high-pressure liquid state passes through the seventh region 53a of the third pipe 53 and the heat generating mechanism 31. The medium-temperature, high-pressure liquid refrigerant is heated and gasified by the heating process of the heat generating mechanism 31 and flows to the first auxiliary heat exchanger 29 via the eighth region 53b, the second flow control valve 28, and the ninth region 53c. At this time, the circulation shutter control unit 98 closes the circulation shutter 34 to prevent the indoor air W2a, which has a high temperature and can be used for freeze suppression and defrosting, from returning to the indoor unit 12 (room R). Note that if freeze suppression and defrosting are deemed unnecessary, the second flow control valve 28 may be closed to prevent the refrigerant from being supplied to the first auxiliary heat exchanger 29. If the refrigerant is not supplied to the first auxiliary heat exchanger 29, the circulation fan 33 may be stopped.

[0102] When freeze suppression or defrosting is required, as described with reference to FIG. 8, indoor air W2 warmed by heat exchange with the first auxiliary heat exchanger 29 functioning as a condenser passes through the partition wall 35 and is supplied to the outdoor heat exchanger 21, thereby performing freeze suppression or defrosting. In this case, by closing the first flow control valve 27, refrigerant does not flow through the fourth pipe 54, and the second auxiliary heat exchanger 30 essentially stops functioning. As a result of heat exchange in the first auxiliary heat exchanger 29, low-temperature, high-pressure refrigerant passes through the first pipe 51 (fourth region 51d) and returns to the compressor 23 via the accumulator 24. As a result of heat exchange in the first auxiliary heat exchanger 29, some refrigerant may become liquid and return to the accumulator 24 in a two-phase gas-liquid state. However, the amount of liquefaction is not large, and due to the gas-liquid separation process in the accumulator 24, only gaseous refrigerant is returned to the compressor 23.

[0103] In this way, when the air conditioner 10 performs heating operation, the indoor air W2 heated by heat exchange with the first auxiliary heat exchanger 29, which functions as a condenser, passes through the partition wall 35 and is supplied to the outdoor heat exchanger 21, where freeze suppression and defrosting are performed, as necessary. As a result, the outdoor heat exchanger 21 does not need to stop heating operation for defrosting operation, and continuous and efficient heating operation can be performed.

[0104] During heating operation, the refrigerant that has been converted into a high-pressure, medium-temperature liquid state through heat exchange in the indoor unit 12 is warmed by the heat generating mechanism 31, converted into a gaseous state, and supplied to the first auxiliary heat exchanger 29. At this time, the refrigerant is returned to the compressor 23 side without being subcooled. As a result, the pressure of the low-pressure gaseous refrigerant returning from the outdoor heat exchanger 21 side can be increased by mixing with the high-pressure gaseous refrigerant that has passed through the first auxiliary heat exchanger 29. In other words, the pressure of the refrigerant returned to the compressor 23 can be increased compared to when the refrigerant returns only from the outdoor heat exchanger 21 side. This makes it possible to reduce the workload of the compressor 23. This also contributes to energy savings.

[0105] <Summary> The air conditioner 10 according to the embodiment described above includes an indoor unit 12 including an indoor heat exchanger 41 and an indoor blower fan 42, an outdoor unit 11 including an outdoor heat exchanger 21 and an outdoor blower fan 22, a first pipe 51 connecting the indoor heat exchanger 41 and the outdoor heat exchanger 21 and through which a refrigerant flows, a second pipe 52 connecting the outdoor heat exchanger 21 and the indoor heat exchanger 41 and through which a refrigerant flows, a compressor 23 provided in the first pipe 51 and having an inlet 23a for drawing in the refrigerant and an outlet 23b for discharging the refrigerant, a four-way valve 25 provided in the first pipe 51 and capable of changing the direction in which the refrigerant flows, an expansion valve 26 provided in the second pipe 52, the first pipe 51 between the four-way valve 25 and the inlet 23a of the compressor 23, and the expansion valve 26. a third pipe 53 connecting the first pipe 51 between the four-way valve 25 and the outdoor heat exchanger 21 and the second pipe 52 between the expansion valve 26 and the outdoor heat exchanger 21; a fourth pipe 54 connecting the first pipe 51 between the four-way valve 25 and the outdoor heat exchanger 21 and the second pipe 52 between the expansion valve 26 and the outdoor heat exchanger 21; a first auxiliary heat exchanger 29 provided on the third pipe 53; a second auxiliary heat exchanger 30 provided on the fourth pipe 54; a circulation air duct pipe 32 that can pass air taken in a room (room R) where the indoor unit 12 is installed through the first auxiliary heat exchanger 29 and the second auxiliary heat exchanger 30 in this order and return it to the room (room R); and a circulation fan 33 (auxiliary fan) that is provided in part of the circulation air duct pipe 32 and that moves air between the room (room R) and the outdoor unit 11.

[0106] This configuration allows the outdoor unit 11 to dehumidify the indoor air W, for example, at an early stage after the start of cooling, separate from the heat exchange process of the indoor unit 12. As a result, the indoor unit 12 can smoothly perform heat (sensible heat) processing, which is likely to cause a drop in the indoor temperature, using the dehumidified indoor air W3 at an early stage after the start of cooling operation, without expending energy on water vapor processing for dehumidification. As a result, the cooling state desired by the user of the air conditioner 10 (indoor unit 12) can be quickly achieved. Furthermore, condensation water D generated when the indoor air W is dehumidified via the first auxiliary heat exchanger 29 in the outdoor unit 11 can be used to clean the fins and other components formed on the surface of the outdoor heat exchanger 21, thereby preventing a decrease in heat exchange efficiency due to contamination of the outdoor heat exchanger 21. This contributes to maintaining or improving the efficiency of cooling operation. In other words, it contributes to energy conservation. Furthermore, by supplying the condensed water D to the outdoor heat exchanger 21, it is possible to lower the ambient temperature of the outdoor heat exchanger 21, and even if the temperature of the gaseous refrigerant supplied to the outdoor heat exchanger 21 is lowered, it is possible to perform heat exchange of the refrigerant required for cooling operation. It is also possible to lower the temperature of the refrigerant supplied from the compressor 23, and the workload of the compressor 23 can be reduced. This also contributes to energy savings during cooling operation of the air conditioner 10. Furthermore, because the indoor air W is dehumidified on the outdoor unit 11 side, there is no need to increase the size or capacity of the indoor unit 12 for dehumidification, which can contribute to a smaller indoor unit 12 and ultimately a smaller air conditioner 10.

[0107] Furthermore, in the air conditioner 10, for example, the outdoor unit 11 may include an outdoor main air duct 11M in which the outdoor heat exchanger 21 and the outdoor blower fan 22 are disposed, an outdoor auxiliary air duct 11S provided above the outdoor main air duct 11M in which the first auxiliary heat exchanger 29 and the second auxiliary heat exchanger 30 are disposed, and a partition wall 35 having a plurality of through-holes 35a formed therein, through which gas and liquid can pass, separating the outdoor main air duct 11M from the outdoor auxiliary air duct 11S. With this configuration, for example, condensed water D generated in the first auxiliary heat exchanger 29 during cooling operation can be supplied to the outdoor heat exchanger 21 side through the through-holes 35a, enabling cleaning of the outdoor heat exchanger 21 and cooling of the outdoor heat exchanger 21 and the outdoor air surrounding it. As a result, this can contribute to improved cooling efficiency and energy conservation during cooling operation.

[0108] Furthermore, the circulation fan 33 of the air conditioner 10 may be provided in, for example, the outdoor unit 11. With this configuration, for example, the indoor air W in the room (room R) can be circulated smoothly (circulated between the indoor unit 12 side and the outdoor unit 11 side). Furthermore, by arranging the circulation fan 33 on the outdoor unit 11 side, it is possible to suppress the transmission of drive noise into the room (room R), which can contribute to improving the quietness of the indoor unit 12.

[0109] The air conditioner 10 may further include a heat generating mechanism 31 capable of heating the refrigerant flowing through the third pipe 53. With this configuration, for example, it becomes possible to increase the temperature of the refrigerant supplied from the indoor heat exchanger 41 to the first auxiliary heat exchanger 29 during heating operation. This also makes it possible to increase the temperature of the indoor air W supplied to the outdoor auxiliary air duct section 11S and supply it to the outdoor heat exchanger 21 side, which can contribute to preventing freezing and defrosting of the outdoor heat exchanger 21. As a result, a defrosting operation is not required during heating operation, making continuous heating operation possible and achieving efficient heating.

[0110] Furthermore, in the air conditioner 10, the heat generating mechanism 31 may be configured with a thermoelectric element (for example, a Peltier element). With this configuration, by controlling the heat generating mechanism 31 (thermoelectric element), it becomes possible, for example, to raise the temperature of the refrigerant during heating operation and to cool the refrigerant during cooling operation, thereby improving the heat exchange efficiency of the first auxiliary heat exchanger 29 and improving the dehumidifying effect during cooling operation and the anti-freezing effect and defrosting effect during heating operation.

[0111] Furthermore, in the air conditioner 10, an on-off valve (first flow control valve 27) may be provided on the fourth pipe 54. According to this configuration, for example, during heating operation, closing the on-off valve (first flow control valve 27) suppresses the flow of low-temperature refrigerant in the second auxiliary heat exchanger 30, and the temperature of the indoor air W2 can be raised satisfactorily in the first auxiliary heat exchanger 29. As a result, freezing of the outdoor heat exchanger 21 can be suppressed and defrosting can be performed efficiently.

[0112] Furthermore, in the air conditioner 10, the circulation air duct 32 may be provided with a vent valve (circulation shutter 34) that can close the circulation air duct 32. With this configuration, for example, during heating operation, the indoor air W2 heated by the first auxiliary heat exchanger 29 is prevented from returning to the room (room R), and can be efficiently supplied to the outdoor heat exchanger 21. As a result, freezing of the outdoor heat exchanger 21 can be more efficiently prevented and defrosted.

[0113] Although the air conditioner 10 of the above-described embodiment has been described as being configured to circulate the indoor air W between the indoor unit 12 side and the outdoor unit 11 side, it can also be operated without circulating the indoor air W. For example, the first flow control valve 27 and the second flow control valve 28 can be controlled to close, so that refrigerant does not flow through the third pipe 53 and the fourth pipe 54 (they are not in use), and further the circulation fan 33 can be stopped (the circulation air duct pipe 32 is not in use), and cooling operation or heating operation can be performed using a general refrigerant circuit.

[0114] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0115] 10...air conditioning apparatus, 11...outdoor unit, 11M...outdoor main air duct section, 11S...outdoor auxiliary air duct section, 12...indoor unit, 13...refrigerant piping, 14...control device, 15...intake port, 16...exhaust port, 21...outdoor heat exchanger, 22...outdoor blower fan, 23...compressor, 24...accumulator, 25...four-way valve, 26...expansion valve, 27...first flow control valve, 28...second flow control valve, 29...first auxiliary heat exchanger, 30...second auxiliary heat exchanger, 31...heat generating mechanism, 32...circulation air duct piping, 33...circulation fan, 34...circulation shutter, 35...partition section, 41...indoor heat exchanger, 42...indoor blower fan, 51...first piping, 52...second piping, 53...third piping, 54...fourth piping.

Claims

1. an indoor unit including an indoor heat exchanger and an indoor blower fan; an outdoor unit including an outdoor heat exchanger and an outdoor blower fan; a first pipe connecting the indoor heat exchanger and the outdoor heat exchanger and through which a refrigerant flows; a second pipe connecting the outdoor heat exchanger and the indoor heat exchanger and through which the refrigerant flows; a compressor provided in the first pipe, the compressor having a suction port for drawing in 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 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 indoor heat exchanger; a fourth pipe connecting the first pipe between the four-way valve and the outdoor heat exchanger and the second pipe between the expansion valve and the outdoor heat exchanger; a first auxiliary heat exchanger provided in the third pipe; a second auxiliary heat exchanger provided in the fourth pipe; a circulation air duct that allows air taken in a room in which the indoor unit is installed to pass through the first auxiliary heat exchanger and the second auxiliary heat exchanger in this order and return the air to the room; an auxiliary fan provided in a part of the circulating air duct piping to move the air between the indoor unit and the outdoor unit; An air conditioning device comprising:

2. The outdoor unit is an outdoor main air duct section in which the outdoor heat exchanger and the outdoor blower fan are arranged; an outdoor auxiliary air duct section provided above the outdoor main air duct section and in which the first auxiliary heat exchanger and the second auxiliary heat exchanger are disposed; a partition wall portion that separates the outdoor main air passage portion from the outdoor auxiliary air passage portion and that has a plurality of through-holes formed therein through which gas and liquid can pass; The air conditioning apparatus according to claim 1 .

3. The auxiliary fan is provided in the outdoor unit. The air conditioning apparatus according to claim 1.

4. Further, a heat generating mechanism capable of heating the refrigerant flowing through the third pipe is provided. The air conditioning apparatus according to claim 1.

5. The heat generating mechanism is composed of a thermoelectric element. The air conditioning apparatus according to claim 4.

6. Further, an on-off valve is provided in the fourth pipe. The air conditioning apparatus according to claim 1.

7. The circulation air duct piping is provided with a vent valve capable of closing the circulation air duct piping. The air conditioning apparatus according to claim 6.

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