Air conditioner

Abstract

To provide an air conditioner capable of suppressing increase of maintenance work and operation cost, and efficiently and easily performing humidification on an indoor side.SOLUTION: The air conditioning apparatus includes an outdoor unit, a first outdoor heat exchanger, a first receiving chamber, a second outdoor heat exchanger, a second receiving chamber, a third outdoor heat exchanger, an indoor unit, an air supply passage, an air return passage, and a ventilation switching mechanism. When one of the second outdoor heat exchanger and the third outdoor heat exchanger functions as a condenser and the other functions as an evaporator, the air passage switching mechanism is brought into a first state in which one of the first receiving chamber and the second receiving chamber that receive the condenser allows air to circulate between the one of the first receiving chamber and the second receiving chamber and the indoor unit through the air supply air passage and the air return air passage and prevents outside air from being taken in from the outside of the outdoor unit, the ventilation state is switched so that the other of the first storage chamber and the second storage chamber storing the evaporator is in a second state in which circulation of air between the installation side and the other of the first storage chamber and the second storage chamber is suppressed and outside air is allowed to be taken in.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Air conditioners, such as air conditioners, regulate indoor temperatures by absorbing and absorbing heat through the condensation and evaporation of a refrigerant in a refrigeration cycle. During heating operation, the refrigerant evaporates in an outdoor heat exchanger (evaporator) and then condenses in an indoor heat exchanger (condenser). During cooling operation, the refrigerant condenses in the outdoor heat exchanger (condenser) and then evaporates in an indoor heat exchanger (evaporator). When such an air conditioner is operating in heating mode, indoor humidity may be low. Indoor air tends to become dry, especially in winter when outdoor humidity is low. Therefore, it is possible to use an air conditioner in conjunction with a humidifier or to use an air conditioner with a humidifying function. When using a humidifier in combination with an air conditioner, a separate humidifier is installed and operated in the room where the indoor unit is installed. Some air conditioners with a humidifying function include, for example, a moisture adsorbent in the outdoor unit. In this air conditioner, moisture is adsorbed onto the adsorbent, and the moisture is heated by a heater or the like and supplied to the room, thereby humidifying the room. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6881578 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the combined use of a humidifier poses problems such as increased maintenance work for the humidifier and increased operating costs, etc. Similarly, air conditioners equipped with a humidifying function also have problems such as the need for maintenance of the adsorbent, and in environments with low outdoor humidity, it can be difficult to smoothly replenish moisture from the outside air, making efficient humidification impossible.

[0005] One example of a problem to be solved by the present invention is to provide an air conditioner that can efficiently and easily humidify the indoor side while suppressing increases in maintenance work and operating costs, etc. [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 first four-way valve, a first expansion valve, a third pipe, a second outdoor heat exchanger, a first storage chamber, a third outdoor heat exchanger, a second storage chamber, a second expansion valve, a second four-way valve, an air supply air duct, an air return air duct, and an airflow switching mechanism. The indoor unit includes an indoor heat exchanger and an indoor blower fan. The outdoor unit includes a first outdoor heat exchanger and an outdoor blower fan. The first pipe connects the indoor heat exchanger and the first outdoor heat exchanger, and a refrigerant flows through it. The second pipe connects the first outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows through it. The compressor is provided in the first piping and has an inlet port for drawing in the refrigerant and an outlet port for discharging the refrigerant. A first four-way valve is provided in the first piping and is capable of changing the direction of refrigerant flow. A first expansion valve is provided in the second piping. A third piping is provided in the outdoor unit and connects the first piping between the inlet port and the first four-way valve and the first piping between the first four-way valve and the indoor heat exchanger. A second outdoor heat exchanger is provided in the third piping. A first storage chamber houses the second outdoor heat exchanger and a first auxiliary fan. A third outdoor heat exchanger is provided in the third piping and is provided in series with the second outdoor heat exchanger. A second storage chamber houses the third outdoor heat exchanger and a second auxiliary fan. A second expansion valve is provided in the third piping between the second outdoor heat exchanger and the third outdoor heat exchanger. A second four-way valve is provided in the third piping and is capable of changing the direction of refrigerant flow. An air supply duct supplies air from the installation side of the indoor unit to either the first storage chamber or the second storage chamber. An air return duct returns air that has been supplied to either the first storage chamber or the second storage chamber and passed through it to the installation side.The ventilation switching mechanism switches the ventilation states of the first storage chamber and the second storage chamber so that, when either the second outdoor heat exchanger or the third outdoor heat exchanger functions as a condenser and the other functions as an evaporator, either the first storage chamber or the second storage chamber that houses the condenser is in a first state that allows air to circulate between the installation side of the indoor unit via the air supply air duct and the air return air duct and inhibits the intake of outside air from outside the outdoor unit, and the other of the first storage chamber or the second storage chamber that houses the evaporator is in a second state that inhibits air from circulating between the installation side and allows the intake of outside air.

[0007] Furthermore, the third piping of the air conditioning apparatus may be provided with a heat generating mechanism, for example, between the second four-way valve and a connection portion with the first piping between the first four-way valve and the indoor heat exchanger.

[0008] The air conditioning apparatus may also include, for example, a fourth pipe connected to the second pipe between the first expansion valve and the first outdoor heat exchanger, and a pipe between one end of the third pipe and the second four-way valve, or a pipe between the other end of the third pipe and the second four-way valve, and a fourth outdoor heat exchanger provided on the fourth pipe.

[0009] According to the above air conditioner, it is possible to provide an air conditioner that can efficiently and easily humidify the indoor side. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a refrigerant system diagram of an air conditioner according to an embodiment, and is also an exemplary schematic diagram showing the flow of refrigerant during humidifying heating 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 cooling operation. [Figure 3]FIG. 3 is an exemplary schematic explanatory diagram showing the positions of the intake ports of the air supply air duct and the discharge ports of the air return air duct 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 air circulating between the indoor unit and the outdoor unit when humidifying the indoor unit side of the air conditioner according to the embodiment. [Figure 5] FIG. 5 is an illustrative and schematic front view showing the configuration of the outdoor unit of the air conditioner according to the embodiment. [Figure 6] FIG. 6 is an exemplary schematic side view showing the configuration of the outdoor unit of the air conditioner according to the embodiment. [Figure 7] FIG. 7 is an exemplary schematic explanatory diagram showing the frosting process in the first storage chamber and the humidification process in the second storage chamber on the outdoor unit side of the air conditioner according to the embodiment. [Figure 8] FIG. 8 is an exemplary schematic explanatory diagram showing the humidification process in the first storage chamber and the frosting process in the second storage chamber on the outdoor unit side of the air conditioner according to the embodiment. [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

[0011] 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.

[0012] 1 and 2 are refrigerant system diagrams of an air conditioner 10 according to an embodiment, and FIG. 1 is also an exemplary and schematic diagram showing the flow of refrigerant during humidifying heating operation. FIG. 2 is an exemplary and schematic diagram showing the flow of refrigerant during cooling operation. The air conditioner 10 is, for example, a home air conditioner. In addition to normal heating and cooling operation, the air conditioner 10 of this embodiment is equipped with a humidifying and heating function that humidifies the indoor air by using moisture obtained by defrosting frost generated on the outdoor unit during heating operation. Note that the air conditioner 10 is not limited to this example and may be another air conditioner, such as a commercial air conditioner.

[0013] 1 and 2, an air conditioner 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.

[0014] 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.

[0015] The outdoor unit 11 has a refrigerant piping 13, a first outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a first four-way valve 25, a second four-way valve 26, a three-way valve 27, a first expansion valve 28, a second expansion valve 29, a third expansion valve 30, a flow control valve 31, a second outdoor heat exchanger 32, a first auxiliary fan 33, a third outdoor heat exchanger 34, a second auxiliary fan 35, a fourth outdoor heat exchanger 36, an air supply air duct 37, an air return air duct 38, and a heat generation mechanism 41.

[0016] The indoor unit 12 has an indoor heat exchanger 42, an indoor blower fan 43, an air supply air duct 37, an air return air duct 38, etc. In other words, the air supply air duct 37 and the air return air duct 38 are air duct pipes arranged across the outdoor unit 11 and the indoor unit 12.

[0017] 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.

[0018] The first piping 51 connects the indoor heat exchanger 42 and the first outdoor heat exchanger 21. The compressor 23, the accumulator 24, and the first 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 first four-way valve 25 and the indoor heat exchanger 42. The second region 51b is a piping region that connects the first 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 first four-way valve 25. The fourth region 51d is a piping region that connects the first four-way valve 25 and the first outdoor heat exchanger 21.

[0019] The second piping 52 connects the first outdoor heat exchanger 21 and the indoor heat exchanger 42. The first expansion valve 28 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 first outdoor heat exchanger 21 and the first expansion valve 28. The sixth region 52b is a piping region that connects the first expansion valve 28 and the indoor heat exchanger 42.

[0020] The third piping 53 connects the first piping 51 (second region 51b) between the suction port 23a of the compressor 23 and the first four-way valve 25, and the first piping 51 (first region 51a) between the first four-way valve 25 and the indoor heat exchanger 42. The second four-way valve 26, the second expansion valve 29, the flow control valve 31, the second outdoor heat exchanger 32, the third outdoor heat exchanger 34, and the heat generating mechanism 41 are provided in the third piping 53. The third piping 53 has a seventh region 53a, an eighth region 53b, a ninth region 53c, a tenth region 53d, an eleventh region 53e, a twelfth region 53f, a thirteenth region 53g, and a fourteenth region 53h. The seventh region 53a is a piping region that connects the first piping 51 (first region 51a) and the flow control valve 31. The eighth region 53b is a piping region that connects the flow control valve 31 and the heat generation mechanism 41. The ninth region 53c is a piping region that connects the heat generation mechanism 41 and the second four-way valve 26. The tenth region 53d is a piping region that connects the second four-way valve 26 and the second outdoor heat exchanger 32. The eleventh region 53e is a piping region that connects the second outdoor heat exchanger 32 and the second expansion valve 29. The twelfth region 53f is a piping region that connects the second expansion valve 29 and the third outdoor heat exchanger 34. The thirteenth region 53g is a piping region that connects the third outdoor heat exchanger 34 and the second four-way valve 26. The fourteenth region 53h is a piping region that connects the second four-way valve 26 and the first piping 51 (the second region 51b).

[0021] The fourth piping 54 connects the second piping 52 (fifth region 52a) between the first expansion valve 28 and the first outdoor heat exchanger 21 to the piping (ninth region 53c) between one end of the third piping 53 and the second four-way valve 26, or to the piping (fourteenth region 53h) between the other end of the third piping 53 and the second four-way valve 26. The fourth outdoor heat exchanger 36, the three-way valve 27, and the third expansion valve 30 are provided in the fourth piping 54. The fourth piping 54 has a fifteenth region 54a, a sixteenth region 54b, a seventeenth region 54c, an eighteenth region 54d, and a nineteenth region 54e. The fifteenth region 54a is a piping region that connects the ninth region 53c, which is one side of the third piping 53, and the three-way valve 27. The sixteenth region 54b is a piping region that connects the three-way valve 27 and the fourteenth region 53h, which is the other side of the third piping 53. The seventeenth region 54c is a piping region that connects the three-way valve 27 and the fourth outdoor heat exchanger 36. The eighteenth region 54d is a piping region that connects the fourth outdoor heat exchanger 36 and the third expansion valve 30. The nineteenth region 54e is a piping region that connects the third expansion valve 30 and the second piping 52 (fifth region 52a).

[0022] 1, during normal heating operation, the refrigerant flows from the first outdoor heat exchanger 21 to the indoor heat exchanger 42 through the first pipe 51, and then flows from the indoor heat exchanger 42 to the first outdoor heat exchanger 21 through the second pipe 52. During humidifying heating operation, the refrigerant flows through the third pipe 53 in addition to the flow path during normal heating operation. In this case, by controlling the flow path switching of the second four-way valve 26, it is possible to alternately switch the flow of the refrigerant that has flowed from the compressor 23 to the third pipe 53 between a flow state in which the refrigerant flows from the second outdoor heat exchanger 32 functioning as a condenser to the third outdoor heat exchanger 34 functioning as an evaporator, and a flow state in which the refrigerant flows from the third outdoor heat exchanger 34 functioning as a condenser to the second outdoor heat exchanger 32 functioning as an evaporator. In the humidifying heating operation, when the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 is made to function as an evaporator, it is possible to intentionally cause frost to form on the surface of the heat exchanger. After that, the frosted third outdoor heat exchanger 34 or the second outdoor heat exchanger 32 is made to function as a condenser to defrost it. The moisture that can be generated at this time can be used to humidify the air circulating between the outdoor unit 11 and the indoor unit 12. Details of the humidifying heating operation will be described later.

[0023] As shown in FIG. 2, when cooling operation is performed, the refrigerant flows from the indoor heat exchanger 42 to the first outdoor heat exchanger 21 through the first pipe 51, and then flows from the first outdoor heat exchanger 21 to the indoor heat exchanger 42 through the second pipe 52. When cooling operation is performed, a portion of the refrigerant can be caused to flow from the first outdoor heat exchanger 21 to the fourth pipe 54. In this case, the refrigerant is expanded by the third expansion valve 30 to lower its temperature, and then supplied to the fourth outdoor heat exchanger 36, whereby the air around the first outdoor heat exchanger 21 can be cooled. As a result, the heat exchange efficiency of the first outdoor heat exchanger 21 can be improved during cooling operation. The operation of the fourth outdoor heat exchanger 36 will be described in detail later.

[0024] The first outdoor heat exchanger 21 of the outdoor unit 11 absorbs heat as an evaporator or releases heat as a condenser depending on the direction of refrigerant flow. The outdoor blower fan 22 sends air to the first outdoor heat exchanger 21, promoting heat exchange between the refrigerant and air in the first outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the first outdoor heat exchanger 21. As will be described later, the outdoor blower fan 22 also sends air to a fourth outdoor heat exchanger 36 that is arranged in a common air passage with the first outdoor heat exchanger 21, promoting heat exchange in the fourth outdoor heat exchanger 36.

[0025] 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.

[0026] 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.

[0027] The first four-way valve 25 is connected to the indoor heat exchanger 42, the accumulator 24 (on the side of the suction port 23a of the compressor 23), the first outdoor heat exchanger 21, and the discharge port 23b of the compressor 23. The first four-way valve 25 switches the flow paths connected to the indoor heat exchanger 42, the accumulator 24, the first outdoor heat exchanger 21, and the discharge port 23b of the compressor 23, respectively, depending on the operation mode, and changes the direction in which the refrigerant flows.

[0028] As shown in FIG. 1 , during heating operation (humidification heating operation and normal (non-humidification) heating operation), the first four-way valve 25 connects the discharge port 23b of the compressor 23 to the indoor heat exchanger 42 and supplies high-temperature, high-pressure gaseous refrigerant to the indoor heat exchanger 42. During humidification heating operation, a portion of the high-temperature, high-pressure gaseous refrigerant is supplied to the third pipe 53 via the flow control valve 31 to enable humidification. The first four-way valve 25 also connects the first outdoor heat exchanger 21 to the accumulator 24, thereby returning the refrigerant to the compressor 23. During humidification heating operation, the refrigerant that has flowed to the fourth pipe 54 is also returned to the compressor 23 via the accumulator 24. The flow of refrigerant through the third pipe 53 and the fourth pipe 54 and their effects will be described in detail below.

[0029] 2, in cooling operation, the first four-way valve 25 connects the discharge port 23b of the compressor 23 to the first outdoor heat exchanger 21 and supplies high-temperature, high-pressure gaseous refrigerant to the first outdoor heat exchanger 21. The first four-way valve 25 also connects the indoor heat exchanger 42 to the accumulator 24, thereby returning the refrigerant to the compressor 23. When refrigerant is caused to flow through the fourth pipe 54, this refrigerant is also returned to the compressor 23 via the accumulator 24. The flow of refrigerant through the fourth pipe 54 and its effects will be described in detail later.

[0030] During humidifying heating operation, the second four-way valve 26 switches whether to cause the high-temperature, high-pressure gaseous refrigerant flowing from the first pipe 51 (first region 51a) to flow to the third pipe 53 via the tenth region 53d to the second outdoor heat exchanger 32 or via the thirteenth region 53g to the third outdoor heat exchanger 34. As will be described later, during cooling operation, the connection direction of the second four-way valve 26 may be arbitrary, but no flow of refrigerant occurs because the flow control valve 31 is closed.

[0031] The three-way valve 27 switches the connection between the fifteenth region 54a or the sixteenth region 54b of the fourth pipe 54 and the seventeenth region 54c.

[0032] For example, during heating operation (humidification heating operation and normal heating operation), the three-way valve 27 connects the 17th region 54c and the 15th region 54a of the fourth pipe 54. As a result, part of the high-temperature, high-pressure gaseous refrigerant flowing from the first pipe 51 (first region 51a) into the third pipe 53 is supplied to the fourth outdoor heat exchanger 36, which functions as a condenser, via the 15th region 54a and the 17th region 54c, thereby enabling defrosting of the first outdoor heat exchanger 21.

[0033] During cooling operation, the three-way valve 27 connects the 17th region 54c and the 16th region 54b of the fourth pipe 54. As a result, the refrigerant flowing out from the fourth outdoor heat exchanger 36, which functions as an evaporator, is returned to the accumulation 4 (compressor 23) side via the 16th region 54b of the fourth pipe 54.

[0034] The first expansion valve 28, the second expansion valve 29, and the third expansion valve 30 are, for example, electromagnetic expansion valves. However, the first expansion valve 28, the second expansion valve 29, and the third expansion valve 30 may be other types of expansion valves. The opening degrees of the first expansion valve 28, the second expansion valve 29, and the third expansion valve 30 are controlled to adjust the amount of refrigerant passing through, thereby determining the amount of expansion of the refrigerant and adjusting the decrease in refrigerant temperature. During normal heating and cooling operations, the second expansion valve 29 is fully closed. Furthermore, the third expansion valve 30 is fully closed when the fourth outdoor heat exchanger 36 is not used.

[0035] The flow control valve 31 controls the amount of high-temperature, high-pressure gaseous refrigerant flowing from the first pipe 51 (first region 51a) into the third pipe 53. For example, when the flow control valve 31 is fully closed, the flow of refrigerant is blocked, and when the flow control valve 31 is open, the amount of refrigerant flowing in is adjusted. The flow control valve 31 can be an electromagnetic control valve capable of flow control, but basically, any type of valve that can fully open and close the valve may be used, such as an on-off valve.

[0036] During humidifying heating operation, the second outdoor heat exchanger 32 functions as a condenser to release heat or as an evaporator to absorb heat, depending on the refrigerant flow direction based on switching control of the second four-way valve 26. A first auxiliary fan 33 is disposed near the second outdoor heat exchanger 32 and sends air to the second outdoor heat exchanger 32 to promote heat exchange between the refrigerant and air in the second outdoor heat exchanger 32. In other words, the first auxiliary fan 33 generates an airflow that exchanges heat with the second outdoor heat exchanger 32. The second outdoor heat exchanger 32 and the first auxiliary fan 33 are disposed inside the first accommodation chamber 11M, which can form a substantially sealed space. The first storage chamber 11M will be described in detail later, but the first storage chamber 11M can communicate with the indoor unit 12 via an air supply air passage 37 (first air supply air passage 37a) and an air return air passage 38 (first air return air passage 38a) which will be described later. The first storage chamber 11M can also communicate with the outside air via a first outside air ventilation passage 39 which will be described later.

[0037] Similarly, during humidifying heating operation, the third outdoor heat exchanger 34 functions as an evaporator to absorb heat or as a condenser to release heat, depending on the refrigerant flow direction based on switching control of the second four-way valve 26. That is, when the second outdoor heat exchanger 32 functions as a condenser, the third outdoor heat exchanger 34 functions as an evaporator. Conversely, when the second outdoor heat exchanger 32 functions as an evaporator, the third outdoor heat exchanger 34 functions as a condenser. A second auxiliary fan 35 is disposed near the third outdoor heat exchanger 34 and blows air toward the third outdoor heat exchanger 34 to promote heat exchange between the refrigerant and air in the third outdoor heat exchanger 34. In other words, the second auxiliary fan 35 generates an airflow that exchanges heat with the third outdoor heat exchanger 34. The third outdoor heat exchanger 34 and the second auxiliary fan 35 are disposed inside the second storage chamber 11N, which can form a substantially sealed space. The second storage chamber 11N will be described in detail later, but the second storage chamber 11N can communicate with the indoor unit 12 via an air supply air passage 37 (second air supply air passage 37b) and an air return air passage 38 (second air return air passage 38b), which will be described later. The second storage chamber 11N can also communicate with outside air via a second outside air ventilation passage 40, which will be described later.

[0038] The first auxiliary fan 33 and the second auxiliary fan 35 may be, for example, a blower such as a sirocco fan, but are not limited to this and may be any fan of other structure as long as it has a blowing function.

[0039] The first auxiliary fan 33 generates an airflow inside the first storage chamber 11M. When the first storage chamber 11M is in communication with the indoor unit 12 via the air supply airflow 37 (first air supply airflow 37a) and the air return airflow 38 (first air return airflow 38a), the first auxiliary fan 33 draws air from the indoor unit 12 via the first air supply airflow 37a, passes the air through the first storage chamber 11M, and returns the air to the indoor unit 12 via the first air return airflow 38a. In other words, a circulating airflow is generated between the first storage chamber 11M and the indoor unit 12. At this time, the first outside air ventilation path 39 for the first storage chamber 11M is closed, and the air supplied from the indoor unit 12 is controlled not to leak to the outside air side. As will be described later, when the humidifying heating operation is performed, for example, in winter, the second outdoor heat exchanger 32 functions as a condenser and humidifies the air passing through the inside of the first accommodation chamber 11M.

[0040] On the other hand, when first storage chamber 11M is in communication with the outside air via first outside-air ventilation path 39, first auxiliary fan 33 draws outside air into first storage chamber 11M. At this time, first air supply duct 37a and first air return duct 38a for first storage chamber 11M are closed, and air is not supplied to first storage chamber 11M from the indoor unit 12 side (air circulation with the indoor unit 12 side does not occur). As will be described later, during humidifying heating operation, such as in winter, second outdoor heat exchanger 32 functions as an evaporator, and moisture contained in the outside air drawn in by driving first auxiliary fan 33 may frost on the surface of second outdoor heat exchanger 32.

[0041] The second auxiliary fan 35 generates an airflow inside the second storage chamber 11N. When the second storage chamber 11N is in communication with the outside air via the second outside-air ventilation path 40, the second auxiliary fan 35 draws the outside air into the second storage chamber 11N. At this time, the second air supply duct 37b and the second air return duct 38b for the second storage chamber 11N are closed, and air is not supplied to the second storage chamber 11N from the indoor unit 12 side (air circulation with the indoor unit 12 side does not occur). As described above, in winter, for example, when the humidifying heating operation is performed, the third outdoor heat exchanger 34 functions as an evaporator, and moisture contained in the outside air drawn in by the driving of the second auxiliary fan 35 may frost on the surface of the third outdoor heat exchanger 34.

[0042] On the other hand, when the second storage chamber 11N is in communication with the indoor unit 12 via the air supply duct 37 (second air supply duct 37b) and the air return duct 38 (second air return duct 38b), the second auxiliary fan 35 draws air from the indoor unit 12 via the second air supply duct 37b, passes it through the second storage chamber 11N, and returns it to the indoor unit 12 via the second air return duct 38b. In other words, a circulating airflow is generated between the second storage chamber 11N and the indoor unit 12. At this time, the second outdoor air vent 40 to the second storage chamber 11N is closed, and air supplied from the indoor unit 12 is controlled not to leak to the outside air. As described above, during humidifying heating operation, such as in winter, the third outdoor heat exchanger 34 functions as a condenser and humidifies the air passing through the second storage chamber 11N.

[0043] During wet heating operation or normal heating operation, the fourth outdoor heat exchanger 36 is supplied with high-temperature, high-pressure gaseous refrigerant supplied via the fourth pipe 54 (seventeenth region 54c) by switching control of the three-way valve 27, and functions as a condenser to radiate heat. This heat radiation can suppress frosting that may occur in the first outdoor heat exchanger 21 when wet heating operation or normal heating operation is performed in winter, etc. If it is not necessary to suppress frosting, no refrigerant may be supplied to the fourth outdoor heat exchanger 36, and a larger amount of high-temperature, high-pressure gaseous refrigerant may be supplied to the indoor heat exchanger 42, thereby contributing to improved heating efficiency.

[0044] Furthermore, during cooling operation, a portion of the refrigerant supplied to the indoor heat exchanger 42 is supplied to the fourth outdoor heat exchanger 36 via the fourth pipe 54 (18th region 54d) through switching control of the three-way valve 27 and control of the third expansion valve 30. At this time, the liquid refrigerant, which has been changed to a low temperature and low pressure by throttling control of the third expansion valve 30, absorbs heat by heat exchange in the fourth outdoor heat exchanger 36. This heat absorption lowers the temperature of the air surrounding the first outdoor heat exchanger 21, which is located in the same air passage as (adjacent to) the fourth outdoor heat exchanger 36. As a result, even if the temperature of the refrigerant supplied to the first outdoor heat exchanger 21 is lowered during cooling operation, the heat exchange required for cooling operation is possible, reducing the operation of the compressor 23 and contributing to energy savings. Note that if priority is to be given to the cooling function of the indoor heat exchanger 42, refrigerant may not be supplied to the fourth outdoor heat exchanger 36. In this case, a larger amount of low-temperature, low-pressure liquid refrigerant can be supplied to the indoor heat exchanger 42, which can contribute to improving cooling efficiency.

[0045] The air supply duct 37 connects the indoor unit 12 to the first storage chamber 11M and the second storage chamber 11N, and is a pipe for supplying air from the interior of the indoor unit 12 (the room R in which the indoor unit 12 is installed) to the first storage chamber 11M or the second storage chamber 11N from the indoor unit 12 side. The air supply duct 37 can be formed from a metal material, a resin material, or the like. The air supply duct 37 branches midway into a first air supply duct 37a connected to the first storage chamber 11M and a second air supply duct 37b connected to the second storage chamber 11N. The end of the air supply duct 37 on the indoor unit 12 side is provided with an intake port 37c that opens into the interior of the indoor unit 12. A first intake valve 37d is provided midway (for example, near the end on the first storage chamber 11M side) of the first air supply duct 37a, which is formed by separating the air supply duct 37. Similarly, a second intake valve 37e is provided midway (for example, near the end on the second storage chamber 11N side) in second air supply air passage 37b, which is formed by separating air supply air passage 37. First intake valve 37d and second intake valve 37e are configured as on-off valves, and are controlled so that when one is open, the other is closed. In other words, first storage chamber 11M and second storage chamber 11N are alternately connected to indoor unit 12 via air supply air passage 37. Note that first intake valve 37d and second intake valve 37e may have other structures, such as an on-off shutter, as long as they can connect and close first air supply air passage 37a and second air supply air passage 37b.

[0046] The air return duct 38 connects the first storage chamber 11M and the second storage chamber 11N to the indoor unit 12 and is a pipe for returning air from the first storage chamber 11M or the second storage chamber 11N to the indoor unit 12. The air return duct 38 can be formed from a metal material, a resin material, or the like. The air return duct 38 branches into a first air return duct 38a connected to the first storage chamber 11M and a second air return duct 38b connected to the second storage chamber 11N. The end of the air return duct 38 on the indoor unit 12 side is provided with an outlet port 38c that opens into the interior of the indoor unit 12. A first outlet valve 38d is provided in the first air return duct 38a (for example, near the end on the first storage chamber 11M side), which is formed by separating the air return duct 38. Similarly, a second discharge valve 38e is provided midway (for example, near the end on the second storage chamber 11N side) in second air return passage 38b, which is formed by separating air return passage 38. First discharge valve 38d and second discharge valve 38e are configured as on-off valves, and are controlled so that when one is closed, the other is open. In other words, first storage chamber 11M and second storage chamber 11N are alternately connected to indoor unit 12 via air return passage 38. Note that first discharge valve 38d and second discharge valve 38e may have other structures, such as open / close shutters, as long as they can connect and close first air return passage 38a and second air return passage 38b.

[0047] 1 and 2, the air supply duct 37 and the air return duct 38 are branched midway to connect the indoor unit 12 to the first storage chamber 11M and the second storage chamber 11N. In this case, the connection structure on the indoor unit 12 side can be simplified. In other embodiments, the air supply duct 37 and the air return duct 38 may not be branched, and the indoor unit 12 side may be connected to the first storage chamber 11M and the indoor unit 12 side to the second storage chamber 11N by dedicated piping, respectively.

[0048] As described above, the first outdoor air vent passage 39 is a pipe that connects the inside of the first storage chamber 11M with the outside (the outdoor air side of the outdoor unit 11) and introduces outdoor air into the first storage chamber 11M. The first outdoor air vent passage 39 can be made of a metal material or a resin material. The first outdoor air vent passage 39 is provided with a first ventilation shutter 39a. When the second outdoor heat exchanger 32 housed in the first storage chamber 11M functions as a condenser, the first ventilation shutter 39a closes to block contact between the first storage chamber 11M and outdoor air. On the other hand, when the second outdoor heat exchanger 32 functions as an evaporator, the first ventilation shutter 39a opens to allow outdoor air to be introduced into the first storage chamber 11M.

[0049] As described above, the second outdoor air vent passage 40 is also a pipe that connects the inside of the second storage chamber 11N to the outside (the outdoor air side of the outdoor unit 11) and introduces outdoor air into the second storage chamber 11N. The second outdoor air vent passage 40 can be made of a metal material or a resin material. The second outdoor air vent passage 40 is provided with a second ventilation shutter 40a. When the third outdoor heat exchanger 34 housed in the second storage chamber 11N functions as an evaporator, the second ventilation shutter 40a opens to allow outdoor air to be introduced into the second storage chamber 11N. On the other hand, when the third outdoor heat exchanger 34 housed in the second storage chamber 11N functions as a condenser, the second ventilation shutter 40a closes to block contact between the second storage chamber 11N and the outdoor air.

[0050] The first ventilation shutter 39a and the second ventilation shutter 40a may have other structures, such as on-off valves, as long as they can switch between introducing and not introducing outside air into the first outside air vent passage 39 and the second outside air vent passage 40. While FIGS. 1 and 2 show an example in which two first outside air vent passages 39 and two second outside air vent passages 40 are provided, this is not limiting. By providing a plurality of first outside air vent passages 39 and two second outside air vent passages 40, it is sufficient to smoothly introduce outside air into the first storage chamber 11M or the second storage chamber 11N when the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 functions as an evaporator. For example, one or three or more of each may be provided. In another embodiment, the first outside air ventilation path 39 and the second outside air ventilation path 40 may be formed by slits provided in the outer wall surfaces of the first storage chamber 11M and the second storage chamber 11N. In this case, the first ventilation shutter 39a and the second ventilation shutter 40a may be configured to open and close the slits.

[0051] In this way, air supply air passage 37, first suction valve 37d, second suction valve 37e, air return air passage 38, first discharge valve 38d, second discharge valve 38e, first outdoor air ventilation passage, first ventilation shutter 39a, second outdoor air ventilation passage 40, and second ventilation shutter 40a constitute an ventilation switching mechanism that switches the ventilation state of first storage chamber 11M and second storage chamber 11N. That is, when either second outdoor heat exchanger 32 or third outdoor heat exchanger 34 functions as a condenser and the other functions as an evaporator, either first storage chamber 11M or second storage chamber 11N accommodating the condenser can be in a first state that allows air to circulate between the installation side of indoor unit 12 via air supply air passage 37 and air return air passage 38 and inhibits the intake of outdoor air from outside outdoor unit 11. Also, the other of the first storage chamber 11M and the second storage chamber 11N that houses the evaporator can be in a second state that prevents air from circulating between the other and the installation side of the indoor unit 12 and allows outside air to be taken in. In other words, by alternately switching between the first state and the second state, the ventilation switching mechanism switches the air circulation in the first storage chamber 11M and the second storage chamber 11N, making it possible to continuously humidify the interior air W.

[0052] The heat generating mechanism 41 is provided in the third pipe 53, and further increases the temperature of the refrigerant supplied when the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 functions as a condenser. In other words, the heat generating mechanism 41 more efficiently melts frost that forms on the surfaces of the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 when they function as evaporators, efficiently increasing the humidity in the first storage chamber 11M or the second storage chamber 11N, and more efficiently humidifying the interior air W circulating between the indoor unit 12 side and the first storage chamber 11M or the second storage chamber 11N.

[0053] Furthermore, the heat generating mechanism 41 functions when suppressing frost during humidifying heating operation or normal heating operation, or when defrosting is required due to frost formation, and when it is necessary to further increase the temperature of the refrigerant supplied to the fourth outdoor heat exchanger 36. For example, when it is necessary to improve the heating efficiency of the indoor unit 12 and suppress frost formation or defrost, it may be difficult to increase the amount of refrigerant that can be supplied to the fourth outdoor heat exchanger 36. In this way, by further increasing the temperature of the refrigerant even when the amount of refrigerant supplied to the fourth outdoor heat exchanger 36 is small, it is possible to sufficiently suppress frost formation or perform defrosting even with a small amount of refrigerant. Note that the heat generating mechanism 41 may be configured, for example, by a heater, but may also be configured, for example, by an energy conversion element (Peltier element) that utilizes the interaction between heat and electricity, as long as it is capable of increasing the temperature of the refrigerant. In addition, if the high-temperature refrigerant supplied from compressor 23 can provide sufficient heating control, frost suppression, or defrosting, for example, if air conditioning device 10 is used in an area other than a cold region, or if a sufficient amount of refrigerant can be ensured to circulate, heat generation mechanism 41 may be omitted.

[0054] The indoor heat exchanger 42 of the indoor unit 12 either radiates heat as a condenser or absorbs heat as an evaporator depending on the direction of refrigerant flow. The indoor blower fan 43 blows air to the indoor heat exchanger 42, promoting heat exchange between the refrigerant and air in the indoor heat exchanger 42. In other words, the indoor blower fan 43 generates an airflow that exchanges heat with the indoor heat exchanger 42.

[0055] Fig. 3 is an exemplary and schematic explanatory diagram showing the positions of the intake port 37c of the air supply airflow duct 37 and the discharge port 38c of the air return airflow duct 38 in the indoor unit 12 of the air conditioner 10 according to this embodiment. Fig. 4 is an exemplary and schematic explanatory diagram showing the flow of air (in-unit air W) between the indoor unit 12 and the outdoor unit 11 during humidifying heating operation of the air conditioner 10.

[0056] The intake port 37c of the air supply duct 37 opens, for example, to a portion of the inside of the exterior panel 12a, for example, inside the right end of the indoor unit 12 in FIG. 3 . The intake port 37c may open anywhere as long as it can draw in the interior air W1 inside the indoor unit 12. For example, it is desirable that the intake port 37c open near an intake port (not shown) in the indoor unit 12 that draws in air from the room R in which the indoor unit 12 is installed by driving the indoor blower fan 43. The discharge port 38c of the air return duct 38 may open anywhere as long as it can discharge the interior air W3 humidified by the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 on the outdoor unit 11 side into the indoor unit 12. For example, it is desirable that the discharge port 38c open near the center of the interior of the exterior panel 12a as shown in FIG. 3 to easily supply the humidified interior air W3 to the entire indoor heat exchanger 42.

[0057] As described above, the first auxiliary fan 33 is located in the first storage chamber 11M in which the second outdoor heat exchanger 32 is disposed. Similarly, the second auxiliary fan 35 is located in the second storage chamber 11N in which the third outdoor heat exchanger 34 is disposed. As shown in FIG. 4 , for example, when the second outdoor heat exchanger 32 functions as a condenser, driving the first auxiliary fan 33 causes circulation of interior air W between the indoor unit 12 and the first storage chamber 11M via the air supply air duct 37 and the air return air duct 38. As a result, interior air W1(W) on the indoor unit 12 side (room R side), which may be dry, passes through the air supply air duct 37 and is humidified by passing through the first storage chamber 11M to become interior air W2(W). The interior air W2(W) then passes through the air return air duct 38 as interior air W3(W) and is returned to the indoor unit 12. In other words, it is possible to blow out humidified air (indoor air W4) from the indoor unit 12. Similarly, when the third outdoor heat exchanger 34 functions as a condenser, driving the second auxiliary fan 35 causes circulation of the indoor air W between the indoor unit 12 and the second storage chamber 11N via the air supply air duct 37 and the air return air duct 38. As a result, the indoor air W1(W) on the indoor unit 12 side (room R side), which may be dry, passes through the air supply air duct 37 and is humidified by passing through the second storage chamber 11N to become indoor air W2(W). The indoor air W2(W) then passes through the air return air duct 38 as indoor air W3(W) and is returned to the indoor unit 12 again. In other words, it is possible to blow out humidified air (indoor air W4) from the indoor unit 12.

[0058] 1 and 2, the first auxiliary fan 33 is disposed in the first storage chamber 11M to improve the heat exchange efficiency of the second outdoor heat exchanger 32 and circulate the interior air W, but a fan for improving the heat exchange efficiency and a fan for circulating the interior air W may be provided separately. The same applies to the second storage chamber 11N. The circulation fan may be, for example, an axial fan.

[0059] Fig. 5 is an exemplary schematic explanatory diagram showing the configuration of the outdoor unit 11 of the air conditioning apparatus 10 according to the embodiment. Fig. 6 is an exemplary schematic side view showing the configuration of the outdoor unit 11 of the air conditioning apparatus 10 according to the embodiment.

[0060] As shown in Fig. 5, the outdoor unit 11 of this embodiment includes an outdoor main air duct section 11P and a first storage chamber 11M and a second storage chamber 11N disposed above the outdoor main air duct section 11P. As described above, the first storage chamber 11M and the second storage chamber 11N are each independent housings that are substantially airtight spaces and made of metal plates or the like. The first storage chamber 11M and the second storage chamber 11N may be disposed above the outdoor main air duct section 11P, for example, but are not limited to this. As part of the configuration of the outdoor unit 11, they may be disposed in a position independent of the outdoor main air duct section 11P, for example, a position adjacent to the outdoor unit 11 or a position separated from the outdoor main air duct section 11P.

[0061] The outdoor main air passage 11P is an air passage formed in a space open to outdoor air for flowing air (air around the outdoor unit 11) to an area including the first outdoor heat exchanger 21, the fourth outdoor heat exchanger 36, the outdoor blower fan 22, etc. In the outdoor main air passage 11P, as shown in Fig. 6, for example, the fourth outdoor heat exchanger 36, the first outdoor heat exchanger 21, and the outdoor blower fan 22 are arranged in this order in the direction from the outdoor air inlet 11a formed on the rear side of the outdoor unit 11 to the air outlet 11b formed on the front side of the outdoor unit 11. Therefore, when the outdoor blower fan 22 is driven, outdoor air W0 flows in from the outdoor air inlet 11a, exchanges heat with the fourth outdoor heat exchanger 36, and then further exchanges heat with the first outdoor heat exchanger 21 before being discharged to the outside of the outdoor unit 11 from the air outlet 11b.

[0062] For example, during humidification heating operation or heating operation when the outdoor temperature is low, such as in winter, the ambient air temperature can be increased by heat exchange with the fourth outdoor heat exchanger 36, which functions as a condenser. The heated air can then be supplied to the first outdoor heat exchanger 21. This can contribute to suppressing frost formation on the first outdoor heat exchanger 21, which functions as an evaporator for the humidification heating operation or heating operation. On the other hand, during cooling operation when the outdoor temperature is high, such as in summer, the ambient air temperature can be decreased by heat exchange with the fourth outdoor heat exchanger 36, which functions as an evaporator. In this case, cooled air can be supplied to the first outdoor heat exchanger 21, which functions as a condenser for the cooling operation. As a result, this can contribute to improving the heat exchange efficiency of the first outdoor heat exchanger 21. Furthermore, since the temperature of the air around the first outdoor heat exchanger 21 can be lowered, it becomes possible to lower the temperature of the refrigerant supplied from the compressor 23 to the first outdoor heat exchanger 21, thereby reducing the workload of the compressor 23. In other words, this can contribute to energy-saving operation.

[0063] As explained in Figure 1, an air supply duct 37 and an air return duct 38 are connected to the first storage chamber 11M and the second storage chamber 11N, which realize the circulation of the in-unit air W between the indoor unit 12, and a first outside air ventilation duct 39 and a second outside air ventilation duct 40 are formed, which communicate with the outside air side and allow the outside air to pass through the inside of the first storage chamber 11M and the second storage chamber 11N.

[0064] The first storage chamber 11M and the second storage chamber 11N have substantially the same structure. For example, as shown in Fig. 6, in the first storage chamber 11M, the air supply air passage 37 (first air supply air passage 37a) and the first outdoor air ventilation passage 39 are disposed, for example, facing each other, with the second outdoor heat exchanger 32 and the first auxiliary fan 33 disposed therebetween. That is, the second outdoor heat exchanger 32 is disposed closer to the first air supply air passage 37a, and the first auxiliary fan 33 is disposed closer to the first outdoor air ventilation passage 39. Similarly, although not shown, in the second storage chamber 11N, the air supply air passage 37 (second air supply air passage 37b) and the second outdoor air ventilation passage 40 are disposed, for example, facing each other, with the third outdoor heat exchanger 34 and the second auxiliary fan 35 disposed therebetween. That is, the third outdoor heat exchanger 34 is disposed on the side closer to the second air supply air passage 37b, and the second auxiliary fan 35 is disposed on the side closer to the second outdoor air passage 40.

[0065] As described above, in this embodiment, when humidifying and heating operation is performed, the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 is made to function as an evaporator and absorbs heat, thereby intentionally causing frost to form on the surface of the heat exchanger. Then, the frosted third outdoor heat exchanger 34 or the second outdoor heat exchanger 32 is made to function as a condenser and dissipate heat, thereby defrosting. The moisture that can be generated at this time is used to humidify the air (in-unit air W) circulating between the outdoor unit 11 side and the indoor unit 12 side.

[0066] Fig. 7 is an exemplary schematic explanatory diagram showing the frosting process (processing in the second state) in the first storage chamber 11M on the outdoor unit 11 side of the air conditioner 10 and the humidification process (processing in the first state) in the second storage chamber 11N, for example, during humidification heating operation. Fig. 8 is an exemplary schematic explanatory diagram showing the humidification process (processing in the first state) in the first storage chamber 11M on the outdoor unit 11 side of the air conditioner 10 and the frosting process (processing in the second state) in the second storage chamber 11N, for example, during humidification heating operation.

[0067] First, referring to FIG. 7, a case where frosting occurs in the second outdoor heat exchanger 32 will be described. In this case, the first intake valve 37d of the first air supply air passage 37a (air supply air passage 37) connected to the first storage chamber 11M and the first discharge valve 38d of the first air return air passage 38a (air return air passage 38) are controlled to be closed. As a result, the interior air W on the indoor unit 12 side does not circulate to the first storage chamber 11M even when the first auxiliary fan 33 is driven. Meanwhile, the first ventilation shutter 39a of the first outside air ventilation passage 39 connected to the first storage chamber 11M is opened. As a result, outside air (e.g., low-temperature air in winter) can be supplied to the second outdoor heat exchanger 32 in the first storage chamber 11M by driving the first auxiliary fan 33. That is, when the second outdoor heat exchanger 32 functions as an evaporator, the first accommodation chamber 11M that accommodates the evaporator (second outdoor heat exchanger 32) enters a second state in which air circulation between the first accommodation chamber 11M and the installation side of the indoor unit 12 is inhibited and outdoor air is allowed to enter. At this time, the second outdoor heat exchanger 32 functions as an evaporator and low-temperature refrigerant flows inside, so the surface of the second outdoor heat exchanger 32 is prone to frost formation. That is, by maintaining this state for a predetermined period of time, it is possible to intentionally cause frost to form on the surface of the second outdoor heat exchanger 32.

[0068] At this time, the second intake valve 37e of the second air supply air passage 37b (air supply air passage 37) connected to the second storage chamber 11N and the second discharge valve 38e of the second air return air passage 38b (air return air passage 38) are controlled to be open. As a result, the interior air W on the indoor unit 12 side can be circulated to the first storage chamber 11M by driving the second auxiliary fan 35. Meanwhile, the second ventilation shutter 40a of the second outside air ventilation passage 40 connected to the second storage chamber 11N is closed. As a result, even if the second auxiliary fan 35 is driven, the supply of outside air (for example, low-temperature air in winter) to the second outdoor heat exchanger 32 in the second storage chamber 11N is inhibited (blocked). That is, when the third outdoor heat exchanger 34 functions as a condenser, the second storage chamber 11N that houses the condenser (third outdoor heat exchanger 34) enters a first state in which air is permitted to circulate between the second storage chamber 11N and the installation side of the indoor unit 12, and the intake of outside air is inhibited. At this time, the third outdoor heat exchanger 34 functions as a condenser and a high-temperature refrigerant flows inside, so that if frost has formed on the surface of the third outdoor heat exchanger 34, the frost can be melted. That is, the humidity inside the second storage chamber 11N, which is sealed and essentially isolated from the outside air, can be increased, and the interior air W circulating via the air supply air duct 37 and the air return air duct 38 can be humidified.

[0069] By maintaining the state of the first storage chamber 11M and the second storage chamber 11N shown in FIG. 7 for a predetermined period (e.g., one hour), frost can be formed on the surface of the second outdoor heat exchanger 32 of the first storage chamber 11M. In other words, moisture for humidification can be secured. Then, a cycle of switching the functions of the first storage chamber 11M and the second storage chamber 11N (switching between the first state and the second state) is repeatedly executed every time the predetermined period elapses. The state in which the functions of the first storage chamber 11M and the second storage chamber 11N are switched will be described with reference to FIG. 8.

[0070] As shown in FIG. 8, the first intake valve 37d of the first air supply air passage 37a (air supply air passage 37) connected to the first storage chamber 11M and the first discharge valve 38d of the first air return air passage 38a (air return air passage 38) are controlled to be open. As a result, the interior air W on the indoor unit 12 side can be circulated to the first storage chamber 11M by driving the first auxiliary fan 33. Meanwhile, the first ventilation shutter 39a of the first outside air ventilation passage 39 connected to the first storage chamber 11M is closed. As a result, even if the first auxiliary fan 33 is driven, the supply of outside air (e.g., low-temperature air in winter) to the second outdoor heat exchanger 32 in the first storage chamber 11M is inhibited (blocked). In other words, the ventilation state of the first storage chamber 11M is in the first state. At this time, the second outdoor heat exchanger 32 functions as a condenser and high-temperature refrigerant flows therein, so that it is possible to melt the frost that formed on the surface of the second outdoor heat exchanger 32 in the previous cycle. That is, it is possible to efficiently increase the humidity in the first accommodation chamber 11M, which is in a sealed state and substantially isolated from the outside air. As a result, it is possible to efficiently humidify the interior air W circulating via the air supply air duct 37 and the air return air duct 38.

[0071] Meanwhile, the second intake valve 37e of the second air supply air passage 37b (air supply air passage 37) connected to the second storage chamber 11N and the second discharge valve 38e of the second air return air passage 38b (air return air passage 38) are controlled to be closed. As a result, even if the second auxiliary fan 35 is driven, the interior air W on the indoor unit 12 side is prevented from being supplied to the second outdoor heat exchanger 32 in the second storage chamber 11N. Furthermore, the second ventilation shutter 40a of the second outdoor air ventilation passage 40 connected to the second storage chamber 11N is opened. As a result, the driving of the second auxiliary fan 35 allows outdoor air (e.g., low-temperature air in winter) to be supplied to the third outdoor heat exchanger 34 in the second storage chamber 11N. In other words, the ventilation state of the second storage chamber 11N is in the second state. At this time, the third outdoor heat exchanger 34 functions as an evaporator and low-temperature refrigerant flows inside, so the surface of the third outdoor heat exchanger 34 is prone to frosting. By maintaining this state for a predetermined period of time, it becomes possible to intentionally cause frost to form on the surface of the third outdoor heat exchanger 34. As a result, it is possible to ensure sufficient moisture available for the humidification process in the next cycle.

[0072] In this way, a cycle is repeatedly performed in which the second outdoor heat exchanger 32 in the first storage chamber 11M and the third outdoor heat exchanger 34 in the second storage chamber 11N are alternately switched between a state in which they function as a condenser and a state in which they function as an evaporator. That is, by repeatedly performing a cycle in which the ventilation state is switched between the first state and the second state, it is possible to continuously and easily humidify the interior air W on the indoor unit 12 side, i.e., the air in the room R in which the indoor unit 12 is installed. Furthermore, in this case, it is only necessary to switch the usage states of the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34, and no auxiliary parts such as adsorbents for retaining moisture for humidification are required. This makes it possible to provide an air conditioner 10 that can achieve efficient humidifying heating without requiring maintenance during operation.

[0073] At the start of humidifying heating operation, either the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 may function as an evaporator and the other as a condenser, with the functions being switched alternately in subsequent cycles. For example, the states of the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 may be detected, and the one with frost may be made to function as a condenser first.

[0074] The control device 14 controls the outdoor blower fan 22, the indoor blower fan 43, the first auxiliary fan 33, the second auxiliary fan 35, the first ventilation shutter 39a, the second ventilation shutter 40a, the heat generating mechanism 41, the compressor 23, the various valves, and other components provided in the outdoor unit 11 and the indoor unit 12, and performs humidifying heating operation, normal heating operation, cooling operation, and other operational controls. 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 transmit 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 a 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 integrated 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 may be provided in the indoor unit 12, for example.

[0075] 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.

[0076] 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 71, an indoor fan drive circuit 72, an inverter circuit 73, a first four-way valve drive circuit 74, a second four-way valve drive circuit 75, a three-way valve drive circuit 76, a first expansion valve drive circuit 77, a second expansion valve drive circuit 78, a third expansion valve drive circuit 79, a flow control valve drive circuit 80, an air passage valve drive circuit 81, an auxiliary fan drive circuit 82, a ventilation shutter drive circuit 83, a heat generation mechanism drive circuit 84, and the like.

[0077] The outdoor fan drive circuit 71 is a drive circuit for the outdoor blower fan 22. The indoor fan drive circuit 72 is a drive circuit for the indoor blower fan 43. The inverter circuit 73 inverter-controls the compressor 23 to change the frequency of the compressor 23. The inverter circuit 73 is, for example, a PAM (Pulse Amplitude Modulation) type inverter circuit. However, the inverter circuit 73 is not limited to this example.

[0078] The first four-way valve drive circuit 74 is a drive circuit for the first four-way valve 25. The second four-way valve drive circuit 75 is a drive circuit for the second four-way valve 26. The three-way valve drive circuit 76 is a drive circuit for the three-way valve 27. The first expansion valve drive circuit 77 is a drive circuit for the first expansion valve 28. The second expansion valve drive circuit 78 is a drive circuit for the second expansion valve 29. The third expansion valve drive circuit 79 is a drive circuit for the third expansion valve 30. The flow control valve drive circuit 80 is a drive circuit for the flow control valve 31. The ventilation valve drive circuit 81 is a drive circuit for the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e. The auxiliary fan drive circuit 82 is a drive circuit for the first auxiliary fan 33 and the second auxiliary fan 35. The ventilation shutter drive circuit 83 is a drive circuit for the first ventilation shutter 39a and the second ventilation shutter 40a. The heat generating mechanism drive circuit 84 is a drive circuit for the heat generating mechanism 41.

[0079] The control device 14 is connected to humidity sensors H1, H2, temperature sensors T1 to T7, temperature sensor Su, an outdoor fan drive circuit 71, an indoor fan drive circuit 72, an inverter circuit 73, a first four-way valve drive circuit 74, a second four-way valve drive circuit 75, a three-way valve drive circuit 76, a first expansion valve drive circuit 77, a second expansion valve drive circuit 78, a third expansion valve drive circuit 79, a flow control valve drive circuit 80, an air passage valve drive circuit 81, an auxiliary fan drive circuit 82, a ventilation shutter drive circuit 83, and a heat generation mechanism drive circuit 84. 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, an auxiliary fan control unit 97, a ventilation shutter control unit 98, and a heat generation control unit 99.

[0080] The humidity acquisition unit 90 uses humidity sensors H1 and H2 to detect the humidity of the interior air W1 inside the indoor unit 12 that is drawn into the intake port 37c of the air supply air duct 37 and the humidity of the interior air W3 that is discharged from the discharge port 38c of the air return air duct 38. As shown in FIGS. 1 and 3, the humidity sensor H1 is installed, for example, near the intake port 37c. Furthermore, the humidity sensor H2 is installed near the discharge port 38c. The detected (acquired) humidity can be used to control various valves that control the flow direction, supply amount, and refrigerant flow timing of the refrigerant supplied to the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34.

[0081] The temperature acquisition unit 91 measures the temperatures of various parts in the refrigeration cycle using temperature sensors T1 to T7 and temperature sensor Su. As shown in FIG. 1 and other figures, for example, temperature sensor T1 detects the temperature (T1 value) of the refrigerant inside the indoor heat exchanger 42. Temperature sensor T2 detects the temperature (T2 value) of the refrigerant inside the first outdoor heat exchanger 21. Temperature sensor T3 detects the temperature (T3 value) of the refrigerant inside the second outdoor heat exchanger 32. Temperature sensor T4 detects the temperature (T4 value) of the refrigerant inside the third outdoor heat exchanger 34. Temperature sensor T5 detects the temperature (T5 value) of the refrigerant inside the fourth outdoor heat exchanger 36. Temperature sensor T6 is installed near the intake port 37c of the air supply air duct 37 formed in the indoor unit 12, and detects the temperature (T6 value) of the in-unit air W1 before humidification that is drawn into the air supply air duct 37. Temperature sensor T7 is installed near discharge port 38c of air return duct 38 formed in the indoor unit 12, and detects the temperature (T7 value) of humidified interior air W3 discharged from air return duct 38. 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 installed in various locations in the outdoor unit 11 and indoor unit 12, and the detection results may be used to control the air conditioner 10.

[0082] The operation switching unit 92 switches the air conditioner 10 between humidifying heating operation, normal heating operation (without humidifying function), cooling operation, and other operations.

[0083] 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 71 to control the rotation speed of the motor of the outdoor blower fan 22.

[0084] The indoor fan control unit 94 controls the indoor blower fan 43. For example, the indoor fan control unit 94 controls the indoor fan drive circuit 72 to control the rotation speed of the motor of the indoor blower fan 43, and thereby controls the wind speed and air volume of the air (in-unit air W4) blown out from the indoor unit 12.

[0085] The compressor control unit 95 controls the compressor 23. For example, the compressor control unit 95 controls the inverter circuit 73 to control the frequency (operating frequency) of the compressor 23 through inverter control.

[0086] The valve control unit 96 controls the first four-way valve 25, the second four-way valve 26, the three-way valve 27, the first expansion valve 28, the second expansion valve 29, the third expansion valve 30, the flow control valve 31, the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e. The valve control unit 96 controls the first four-way valve drive circuit 74 to drive the actuator of the first four-way valve 25 and change the direction of refrigerant flow in the first four-way valve 25. The valve control unit 96 controls the second four-way valve drive circuit 75 to drive the actuator of the second four-way valve 26 and change the direction of refrigerant flow in the second four-way valve 26. The valve control unit 96 controls the three-way valve drive circuit 76 to drive the actuator of the three-way valve 27 and change the direction of refrigerant flow in the three-way valve 27. The valve control unit 96 controls the first expansion valve drive circuit 77 to drive the actuator of the first expansion valve 28 and control the amount of refrigerant flowing (expansion amount) in the first expansion valve 28. The valve control unit 96 controls the second expansion valve drive circuit 78 to drive the actuator of the second expansion valve 29 and control the amount of refrigerant flowing (expansion amount) in the second expansion valve 29. The valve control unit 96 controls the third expansion valve drive circuit 79 to drive the actuator of the third expansion valve 30 and control the amount of refrigerant flowing (expansion amount) in the third expansion valve 30. The valve control unit 96 controls the flow control valve drive circuit 80 to drive the actuator of the flow control valve 31 and determine the amount of refrigerant flowing (presence or absence) in the flow control valve 31. The valve control unit 96 controls the ventilation duct valve drive circuit 81 to drive the actuators of the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e, thereby opening and closing the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e, and determines whether or not the in-machine air W is circulated.

[0087] The auxiliary fan control unit 97 controls the first auxiliary fan 33 and the second auxiliary fan 35. For example, the auxiliary fan control unit 97 controls the auxiliary fan drive circuit 82 to control the rotation speed of the motor of the first auxiliary fan 33, thereby controlling the circulation of the interior air W or the outside air in the first accommodation chamber 11M. Furthermore, the auxiliary fan control unit 97 controls the auxiliary fan drive circuit 82 to control the rotation speed of the motor of the second auxiliary fan 35, thereby controlling the circulation of the interior air W or the outside air in the second accommodation chamber 11N.

[0088] The ventilation shutter control unit 98 controls the first ventilation shutter 39a and the second ventilation shutter 40a. For example, the ventilation shutter control unit 98 controls the ventilation shutter drive circuit 83 to drive the actuator of the first ventilation shutter 39a and the actuator of the second ventilation shutter 40a, and controls the intake or exhaust of outside air in the first outside-air ventilation path 39 and the second outside-air ventilation path 40.

[0089] The heat generation control unit 99 controls the heat generation mechanism 41. For example, the heat generation control unit 99 controls the amount of heat generated by the heat generation mechanism 41 (the amount of heat of the refrigerant) by controlling the amount of current flowing through the heat generation mechanism 41.

[0090] The humidifying heating operation, normal heating operation, and cooling operation of the air conditioner 10 of this embodiment configured as described above will be described.

[0091] First, the humidifying and heating operation will be described based on the medium flow pattern shown in Fig. 1. The humidifying and heating operation is basically performed when starting operation of the air conditioner 10, based on operations using a dedicated remote controller or a terminal device with a dedicated application installed. In other embodiments, the humidity and other factors in the room R in which the indoor unit 12 is installed may be detected, and the humidifying and heating operation may be performed automatically when starting heating operation.

[0092] For example, when humidifying and heating operation is performed, each component of the air conditioner 10 is basically stopped. Then, when humidifying and heating operation is performed by operating a dedicated remote controller or terminal device, the outdoor fan control unit 93, indoor fan control unit 94, compressor control unit 95, and auxiliary fan control unit 97 start the outdoor blower fan 22, indoor blower fan 43, compressor 23, first auxiliary fan 33, and second auxiliary fan 35 when humidifying and heating operation starts.

[0093] During humidifying 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 43. For example, the indoor fan control unit 94 controls the indoor blower fan 43 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 a remote controller or the like.

[0094] The auxiliary fan control unit 97 also adjusts the rotation speeds of the first auxiliary fan 33 and the second auxiliary fan 35 depending on the humidification status. For example, when the second outdoor heat exchanger 32 is functioning as a condenser, the rotation speed of the first auxiliary fan 33 installed corresponding to the second outdoor heat exchanger 32 is adjusted according to the humidity of the interior air W1 sent from the indoor unit 12 and the humidity value set by a remote controller or the like, thereby adjusting the humidification efficiency (humidification value). When the second outdoor heat exchanger 32 is functioning as an evaporator, the rotation speed of the first auxiliary fan 33 is set to, for example, the maximum to efficiently supply outside air to the second outdoor heat exchanger 32 and promote frost formation. The rotation speed of the second auxiliary fan 35 installed corresponding to the third outdoor heat exchanger 34 is similarly controlled according to the functional status of the third outdoor heat exchanger 34.

[0095] The compressor control unit 95 adjusts the frequency of the compressor 23 based on the set temperature and other parameters specified by a remote controller or the like.

[0096] When the humidifying heating operation is started, the valve control unit 96 controls the first four-way valve drive circuit 74 to change the refrigerant flow direction through the first four-way valve 25 to heating mode. The valve control unit 96 also controls the first expansion valve drive circuit 77, the second expansion valve drive circuit 78, the third expansion valve drive circuit 79, and the flow control valve drive circuit 80 to change the state of each valve to humidifying heating mode. The valve control unit 96 also controls the second four-way valve drive circuit 75 to switch the refrigerant flow direction through the second four-way valve 26 at predetermined intervals. At this time, the valve control unit 96 controls the ventilation valve drive circuit 81 in response to the switching operation of the second four-way valve 26 to change the open / closed states of the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e.

[0097] In addition, when the humidifying and heating operation is started, the ventilation shutter control unit 98 changes the open / closed state of the first ventilation shutter 39a and the second ventilation shutter 40a in response to the switching operation of the second four-way valve 26 by the valve control unit 96.

[0098] Specifically, the first four-way valve 25 connects the fourth region 51d and the second region 51b of the first pipe 51 to connect the first outdoor heat exchanger 21 side and the accumulator 24. The first 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 42 side. At this time, the flow control valve 31 is controlled to be open. As a result, high-temperature, high-pressure gaseous refrigerant is supplied from the compressor 23 to the indoor heat exchanger 42, and some of the high-temperature, high-pressure gaseous refrigerant is supplied to the third pipe 53 via the flow control valve 31. The high-temperature, high-pressure gaseous refrigerant supplied to the indoor heat exchanger 42 undergoes heat exchange in the indoor heat exchanger 42, which functions as a condenser, and hot air is efficiently supplied to room R.

[0099] The high-temperature, high-pressure gaseous refrigerant that flows to the third pipe 53 side by controlling the opening of the flow control valve 31 can be further heated by passing through the heat generating mechanism 41. As described above, if sufficient heating and frost suppression or defrosting can be performed during humidifying operation, heating by the heat generating mechanism 41 may be omitted. This can contribute to energy savings.

[0100] The second four-way valve 26 determines whether the refrigerant that has reached the second four-way valve 26 via the third piping 53 (ninth region 53c) will flow to the second outdoor heat exchanger 32 side or to the third outdoor heat exchanger 34. When the second four-way valve 26 connects the ninth region 53c of the third piping 53 to the tenth region 53d and the thirteenth region 53g to the fourteenth region 53h, high-temperature, high-pressure gaseous refrigerant flows to the second outdoor heat exchanger 32. In this case, the second outdoor heat exchanger 32 functions as a condenser.

[0101] At this time, as shown in Fig. 8, the first intake valve 37d and the first discharge valve 38d are opened, the indoor unit 12 and the first storage chamber 11M are connected via the first air supply air passage 37a and the first air return air passage 38a, and the inside air W can circulate. In this case, the first ventilation shutter 39a of the first outside air ventilation passage 39 is closed, preventing the inside air W from leaking to the outside air side. In other words, circulation with the outside air is suppressed. Therefore, the ventilation state of the first storage chamber 11M is in the first state.

[0102] At this time, if the second outdoor heat exchanger 32 is frosted or has moisture on its surface, the frost dissipates heat through heat exchange with the high-temperature refrigerant passing through the second outdoor heat exchanger 32, converting the frost into vapor and increasing the humidity inside the first storage chamber 11M. This allows the interior air W (W1) flowing in from the indoor unit 12 through the first air supply air duct 37a to be humidified, and the room R can be humidified by returning the air to the indoor unit 12 through the first air return air duct 38a and blowing it out as warm air from the indoor unit 12. Note that immediately after the start of humidifying heating operation, there may be no frost on the surface of the second outdoor heat exchanger 32 or there may be little moisture. In this case, the humidification efficiency may be low, but continuous humidification is possible from the next cycle onwards, enabling good humidification of the room R.

[0103] The refrigerant that has undergone heat exchange in the second outdoor heat exchanger 32 and has become a medium-temperature, high-pressure liquid refrigerant is supplied to the second expansion valve 29 via the eleventh region 53e. The second expansion valve 29 reduces the pressure of the medium-temperature, high-pressure liquid refrigerant by controlling the throttle of the valve, thereby expanding and lowering its temperature. The low-temperature, low-pressure liquid refrigerant is supplied to the third outdoor heat exchanger 34 via the twelfth region 53f.

[0104] At this time, the second intake valve 37e and the second discharge valve 38e are closed, the second air supply duct 37b and the second air return duct 38b connecting the indoor unit 12 and the second storage chamber 11N are closed, and the inside air W cannot circulate. In this case, the second ventilation shutter 40a of the second outside air vent duct 40 is in an open state, allowing outside air to circulate within the second storage chamber 11N. Therefore, the ventilation state of the second storage chamber 11N is in the second state.

[0105] When humidifying heating operation is used, the outdoor air temperature is often low, and the refrigerant that has been converted into a low-temperature, low-pressure liquid by the second expansion valve 29 absorbs heat through heat exchange in the third outdoor heat exchanger 34, which functions as an evaporator. As a result, frost is likely to form on the surface of the third outdoor heat exchanger 34. In other words, frosting can be intentionally caused on the surface of the third outdoor heat exchanger 34 to ensure that moisture is available for use in the next cycle.

[0106] The low-pressure refrigerant at body temperature that has been vaporized by heat exchange in the third outdoor heat exchanger 34, which functions as an evaporator, passes through the 13th region 53g, the second four-way valve 26, the 14th region 53h, the second region 51b, and returns to the compressor 23 via the accumulator 24.

[0107] The above-described state, in which the second outdoor heat exchanger 32 functions as a condenser and the third outdoor heat exchanger 34 functions as an evaporator, continues for a predetermined period, for example, one hour, which is defined as one cycle. After the predetermined period has elapsed, the second four-way valve 26 controls the ninth region 53c to connect the thirteenth region 53g, and the tenth region 53d to connect the fourteenth region 53h.

[0108] When the flow path is switched by the second four-way valve 26 in this way, as shown in Fig. 7, the first intake valve 37d and the first discharge valve 38d in the first storage chamber 11M are opened, the first air supply airflow path 37a and the first air return airflow path 38a connecting the indoor unit 12 and the first storage chamber 11M are closed, and the inside air W cannot circulate. Also, the first ventilation shutter 39a of the first outside air ventilation path 39 is opened, allowing outside air to circulate within the first storage chamber 11M. Therefore, the ventilation state of the first storage chamber 11M becomes the second state. Meanwhile, in the second storage chamber 11N, the second intake valve 37e and the second discharge valve 38e are opened, and the indoor unit 12 and the second storage chamber 11N are connected via the second air supply air passage 37b and the second air return air passage 38b, allowing the inside air W to circulate. The second ventilation shutter 40a of the second outside air ventilation passage 40 is closed, preventing the inside air W from leaking to the outside air side. In other words, circulation with the outside air is suppressed. Therefore, the ventilation state of the second storage chamber 11N becomes the first state.

[0109] As described above, the surface of the third outdoor heat exchanger 34, which functioned as an evaporator in the previous cycle, is likely to be frosted. The third outdoor heat exchanger 34, which functions as a condenser in the current cycle, dissipates heat through heat exchange as the high-temperature, high-pressure gaseous refrigerant flows, melting the frost. As a result, the humidity in the second storage chamber 11N increases, enabling humidification of the interior air W (W1) flowing from the indoor unit 12 through the second air supply air passage 37b. The interior air W (W1) is returned to the indoor unit 12 through the second air return air passage 38b and blown out as warm air from the indoor unit 12, thereby humidifying the room R. In this case, frost on the third outdoor heat exchanger 34 may have been sufficiently removed in the previous cycle, enabling effective humidification.

[0110] Meanwhile, the refrigerant that has undergone heat exchange in the third outdoor heat exchanger 34 and has become a medium-temperature, high-pressure liquid refrigerant is supplied to the second expansion valve 29 via the twelfth region 53f. The second expansion valve 29 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 low-temperature, low-pressure liquid refrigerant is supplied to the second outdoor heat exchanger 32 via the eleventh region 53e. In other words, the second outdoor heat exchanger 32 functions as an evaporator, and absorbs heat through heat exchange, making it easier for frost to form on the surface of the second outdoor heat exchanger 32. In other words, frosting the surface of the second outdoor heat exchanger 32 intentionally ensures that moisture is available for use in the next cycle.

[0111] The low-temperature, low-pressure refrigerant that is gasified by heat exchange in the second outdoor heat exchanger 32, which functions as an evaporator, passes through the tenth region 53d, the second four-way valve 26, the fourteenth region 53h, the second region 51b, and returns to the compressor 23 via the accumulator 24.

[0112] In this way, by switching the second four-way valve 26 at predetermined intervals and alternately switching the functions of the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 between condenser and evaporator, the in-unit air W circulating through the first storage chamber 11M or the second storage chamber 11N can be continuously and efficiently humidified, and the room R in which the indoor unit 12 is installed can be effectively humidified.

[0113] The refrigerant that has been heat exchanged in the indoor heat exchanger 42 and changed into a medium-temperature, high-pressure liquid state is supplied to the first expansion valve 28 via the sixth region 52b of the second pipe 52. The first expansion valve 28 reduces the temperature of the medium-temperature, high-pressure liquid refrigerant by reducing its pressure through valve throttling control, thereby expanding it. The low-temperature, low-pressure liquid refrigerant is supplied to the first outdoor heat exchanger 21 via the fifth region 52a. The low-temperature, low-pressure liquid refrigerant is gasified by heat exchange in the first outdoor heat exchanger 21, which functions as an evaporator, and returns to the compressor 23 via the first pipe 51 (fourth region 51d), the first four-way valve 25, and the accumulator 24.

[0114] When performing humidifying and heating operation, the first outdoor heat exchanger 21 may function as an evaporator in a low-temperature environment. Therefore, frost may form on the surface of the first outdoor heat exchanger 21. Therefore, a portion of the high-temperature, high-pressure gaseous refrigerant from the compressor 23, which is supplied to the third pipe 53 via the flow control valve 31, is supplied to the fourth outdoor heat exchanger 36 via the fourth pipe 54 (the fifteenth region 54a and the seventeenth region 54c) by switching control of the three-way valve 27. The fourth outdoor heat exchanger 36 functions as a condenser, and the high-temperature, high-pressure gaseous refrigerant supplied to the fourth outdoor heat exchanger 36 exchanges heat with the outside air inside the outdoor unit 11 (the outdoor main air duct portion 11P) and dissipates heat. As a result, frost formation on the first outdoor heat exchanger 21, which functions as an evaporator and is disposed adjacent to the fourth outdoor heat exchanger 36, can be suppressed or defrosted. In this case, unlike a general air conditioner, there is no need to temporarily stop the heating operation to perform a defrosting operation. As a result, the air conditioner 10 of this embodiment can perform a continuous humidifying heating operation.

[0115] The refrigerant that has been heat exchanged in the fourth outdoor heat exchanger 36 and changed into a medium-temperature, high-pressure liquid state is supplied to the third expansion valve 30 via the eighteenth region 54d of the fourth pipe 54. The third expansion valve 30 reduces the temperature of the medium-temperature, high-pressure liquid refrigerant by reducing its pressure through valve throttling control. The low-temperature, low-pressure liquid refrigerant merges with the refrigerant that has been changed into a low-temperature, low-pressure liquid state by the first expansion valve 28 and flows through the fifth region 52a of the second pipe 52 via the nineteenth region 54e, is supplied to the first outdoor heat exchanger 21, and is returned to the compressor 23 as described above. Note that when frost suppression or defrosting using the fourth outdoor heat exchanger 36 is not required, the flow of refrigerant through the fourth pipe 54 can be stopped and the function of the fourth outdoor heat exchanger 36 can be stopped, for example, by fully closing the third expansion valve 30. In this case, a larger amount of high-temperature, high-pressure refrigerant can be supplied to the indoor heat exchanger 42 side, so that efficient heating operation can be performed.

[0116] In this way, the air conditioner 10 of this embodiment can achieve efficient humidification without the need for an adsorbent that adsorbs moisture for humidification or for adding a humidifier with a water tank. Furthermore, because humidification is achieved by the function of the heat exchanger, it is maintenance-free, making it easier to maintain and manage the air conditioner 10 and contributing to reduced running costs.

[0117] When performing normal heating operation without humidification, the basic flow of refrigerant circulating through the first pipe 51 and the second pipe 52 is the same as during humidification heating operation, and although detailed description will be omitted, the flow control valve 31 is controlled to be fully closed. That is, high-temperature, high-pressure gaseous refrigerant is prevented from flowing from the first pipe 51 to the third pipe 53. As a result, the refrigerant circulates between the indoor heat exchanger 42 and the first outdoor heat exchanger 21, allowing normal heating operation to be performed. In this case, if the third expansion valve 30 is controlled to be fully closed, low-temperature, low-pressure liquid refrigerant can be prevented from flowing from the second pipe 52 (fifth region 52a) to the 19th region 54e of the fourth pipe 54 into the fourth outdoor heat exchanger 36. Alternatively, the first suction valve 37d, the first discharge valve 38d, the second suction valve 37e, and the second discharge valve 38e may be controlled to be fully closed to close the air supply airflow path 37 and the air return airflow path 38. As a result, circulation of the interior air W between the indoor unit 12 and the first storage chamber 11M and the second storage chamber 11N is suppressed, and heated air in the room R can be suppressed from flowing toward the outdoor unit 11.

[0118] In this way, the air conditioner 10 of this embodiment can easily accommodate non-humidifying heating operation in which humidification is not performed by controlling the flow control valve 31 and the like.

[0119] During normal heating operation, it may be necessary to suppress or defrost the first outdoor heat exchanger 21 using the fourth outdoor heat exchanger 36, which functions as a condenser. In this case, the second expansion valve 29 is controlled to be fully closed, and the flow control valve 31 is controlled to be open. The three-way valve 27 is also controlled to connect the fifteenth region 54a and the seventeenth region 54c of the fourth piping 54. As a result, high-pressure, high-temperature gaseous refrigerant flows to the fourth outdoor heat exchanger 36, which functions as a condenser, to suppress or defrost the frost. This means that continuous heating operation can be performed without the need to temporarily stop heating operation to perform a defrosting operation. Note that some of the high-pressure, high-temperature gaseous refrigerant flows into the third piping 53 via the second four-way valve 26. However, because the second expansion valve 29 is controlled to be fully closed, no refrigerant flows, and the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 do not function.

[0120] Next, cooling operation will be described based on the medium flow pattern shown in Fig. 2. In cooling operation, as in the normal heating operation described above, the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 do not function. Therefore, the air supply air duct 37 and the air return air duct 38 are closed, and there is no need to circulate the in-unit air W between the indoor unit 12 and the first storage chamber 11M or the second storage chamber 11N.

[0121] For example, when the air conditioning apparatus 10 starts up and the cooling operation starts simultaneously, the outdoor blower fan 22, the compressor 23, and the indoor blower fan 43 are stopped. In this case, the outdoor fan control unit 93, the indoor fan control unit 94, and the compressor control unit 95 start the outdoor blower fan 22, the compressor 23, and the indoor blower fan 43 when the cooling operation starts.

[0122] 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 43. For example, the indoor fan control unit 94 controls the indoor blower fan 43 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 a remote controller or the like. As described above, the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 do not function, and therefore the first auxiliary fan 33 and the second auxiliary fan 35 remain stopped.

[0123] The compressor control unit 95 adjusts the frequency of the compressor 23 based on the set temperature and other parameters specified by a remote controller or the like.

[0124] When the cooling operation starts, the valve control unit 96 controls the first four-way valve drive circuit 74 to change the refrigerant flow direction in the first four-way valve 25 to cooling. The valve control unit 96 also controls the first expansion valve drive circuit 77, the second expansion valve drive circuit 78, the third expansion valve drive circuit 79, and the flow control valve drive circuit 80 to change the state of each valve to cooling. Because the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 are not functioning, the valve control unit 96 does not control the second four-way valve drive circuit 75. Therefore, the second four-way valve 26 maintains the state it was in when the cooling operation started, for example. The second expansion valve drive circuit 78 also fully closes the second expansion valve 29 to suppress the flow of refrigerant in the third pipe 53. The valve control unit 96 also controls the ventilation duct valve drive circuit 81 to fully close the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e, thereby closing the air supply duct 37 and the air return duct 38, thereby preventing the interior air W cooled during cooling operation from leaking into the outdoor unit 11. The ventilation shutter control unit 98 controls the ventilation shutter drive circuit 83 to close the first ventilation shutter 39a and the second ventilation shutter 40a. As a result, the first storage chamber 11M and the second storage chamber 11N are isolated from the outside air, preventing the intrusion of dust and other particles and preventing the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 from becoming dirty.

[0125] Specifically, the first four-way valve 25 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 and the first outdoor heat exchanger 21. As a result, high-pressure, high-temperature gaseous refrigerant discharged from the compressor 23 is supplied to the first outdoor heat exchanger 21. The first outdoor heat exchanger 21 functions as a condenser and performs heat exchange of the refrigerant.

[0126] The medium-temperature, high-pressure refrigerant in a nearly liquid state discharged from the first outdoor heat exchanger 21 passes through the fifth region 52a of the second pipe 52 and is supplied to the first expansion valve 28. The first expansion valve 28 reduces the pressure of the medium-temperature, high-pressure liquid refrigerant by controlling the throttle of the valve, thereby expanding and lowering its temperature. The low-temperature, low-pressure liquid refrigerant is supplied to the indoor heat exchanger 42 via the sixth region 52b. As a result of heat exchange in the indoor heat exchanger 42, the temperature of the interior air W is lowered, and cool air can be blown into the room R by driving the indoor blower fan 43. The refrigerant discharged from the indoor heat exchanger 42 returns to the accumulator 24 via the first region 51a, the first four-way valve 25, and the second region 51b of the first pipe 51 and is sent to the compressor 23 again.

[0127] A portion of the medium-temperature, high-pressure refrigerant in a nearly liquid state discharged from the first outdoor heat exchanger 21 flows through the 19th region 54e of the fourth pipe 54 connected to the fifth region 52a of the second pipe 52 and is supplied to the third expansion valve 30. The third expansion valve 30 reduces the temperature of the medium-temperature, high-pressure liquid refrigerant by controlling the throttle of the valve to reduce its pressure and expand it. The low-temperature, low-pressure liquid refrigerant is supplied to the fourth outdoor heat exchanger 36 via the 18th region 54d. The fourth outdoor heat exchanger 36, which functions as an evaporator, absorbs heat as a result of heat exchange, thereby lowering the temperature of the air surrounding the fourth outdoor heat exchanger 36. In other words, the outdoor air temperature in the outdoor main air duct section 11P of the outdoor unit 11 in which the fourth outdoor heat exchanger 36 is disposed can be lowered, thereby cooling the first outdoor heat exchanger 21 disposed adjacent to the fourth outdoor heat exchanger 36 in the outdoor main air duct section 11P. As a result, heat exchange required during cooling operation is possible even if the temperature of the refrigerant supplied to the first outdoor heat exchanger 21 is lowered. Therefore, it is possible to reduce the operation of the compressor 23, which can contribute to energy conservation.

[0128] When it is desired to prioritize the cooling function of the indoor heat exchanger 42, the third expansion valve 30 is controlled to be fully closed so that refrigerant is not supplied to the fourth outdoor heat exchanger 36. In this case, the amount of refrigerant circulating through the second pipe 52 and the first pipe 51 can be increased, so that a larger amount of low-temperature, low-pressure liquid refrigerant can be supplied to the indoor heat exchanger 42, which can contribute to improving cooling efficiency.

[0129] The refrigerant discharged from the fourth outdoor heat exchanger 36 returns to the accumulator 24 via the 17th region 54c, the three-way valve 27, the 16th region 54b, the 14th region 53h, and the second region 51b, and is sent to the compressor 23 again.

[0130] In this way, the air conditioner 10 of this embodiment, which is capable of humidifying heating operation, can achieve efficient cooling while saving energy in cooling operation.

[0131] In the air conditioner 10 of this embodiment, the amount of humidification of the interior air W can be adjusted, for example, by controlling the valve opening amount of the flow control valve 31 and adjusting the amount of refrigerant supplied to the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34. In another example, the amount of humidification may be adjusted by adjusting the amount of interior air W passing through the air supply duct 37 and the air return duct 38 by controlling the valve opening amounts of the first suction valve 37d, the second suction valve 37e, the first discharge valve 38d, and the second discharge valve 38e.

[0132] 3 shows an example in which the intake port 37c of the air supply airflow duct 37 and the discharge port 38c of the air return airflow duct 38 are provided inside the indoor unit 12. In other embodiments, the intake port 37c and the discharge port 38c may be opened on the surface of the indoor unit 12, so that dry air is directly drawn in from the room R and humidified air is directly returned to the room R.

[0133] Furthermore, in this embodiment, an example has been shown in which two sets of heat exchangers are provided: the second outdoor heat exchanger 32 housed in the first storage chamber 11M and the third outdoor heat exchanger 34 housed in the second storage chamber 11N. The configuration has been shown in which evaporation and condensation are alternately performed to achieve continuous humidification. In a modified example, the storage chambers housing the heat exchangers may be configured as one set. In this case, humidification will be intermittent, but this can contribute to simplifying the configuration of the air conditioner and reducing costs.

[0134] <Summary> The air conditioner 10 according to the embodiment described above includes the indoor unit 12, the outdoor unit 11, the first piping 51, the second piping 52, the compressor 23, the first four-way valve 25, the first expansion valve 28, the third piping 53, the second outdoor heat exchanger 32, the first storage chamber 11M, the third outdoor heat exchanger 34, the second storage chamber 11N, the second expansion valve 29, and the third four-way valve 25. , a second four-way valve 26, an air supply air passage 37, an air return air passage 38, and an air ventilation switching mechanism (air supply air passage 37, first suction valve 37d, second suction valve 37e, air return air passage 38, first discharge valve 38d, second discharge valve 38e, first outdoor air ventilation passage, first ventilation shutter 39a, second outdoor air ventilation passage 40, second ventilation shutter 40a). The indoor unit 12 includes an indoor heat exchanger 42 and an indoor blower fan 43. The outdoor unit 11 includes a first outdoor heat exchanger 21 and an outdoor blower fan 22. A first pipe 51 connects the indoor heat exchanger 42 and the first outdoor heat exchanger 21, and a refrigerant flows through the first pipe 51. The second piping 52 connects the first outdoor heat exchanger 21 and the indoor heat exchanger 42, and refrigerant flows through it. The compressor 23 is provided on the first piping 51 and has an inlet 23a for drawing in the refrigerant and an outlet 23b for discharging the refrigerant. The first four-way valve 25 is provided on the first piping 51 and is capable of changing the direction of refrigerant flow. The first expansion valve 28 is provided on the second piping 52. The third piping 53 is provided in the outdoor unit 11 and connects the first piping 51 between the inlet 23a and the first four-way valve 25 and the first piping 51 between the first four-way valve 25 and the indoor heat exchanger 42. The second outdoor heat exchanger 32 is provided on the third piping 53. The first accommodation chamber 11M accommodates the second outdoor heat exchanger 32 and the first auxiliary fan 33. The third outdoor heat exchanger 34 is provided on the third piping 53 and is provided in series with the second outdoor heat exchanger 32. The second storage chamber 11N accommodates the third outdoor heat exchanger 34 and the second auxiliary fan 35. The second expansion valve 29 is provided on the third piping 53 between the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34. The second four-way valve 26 is provided on the third piping 53 and is capable of changing the direction of refrigerant flow. The air supply air passage 37 supplies air on the installation side of the indoor unit 12 to either the first storage chamber 11M or the second storage chamber 1N.The air return passage 38 returns air that has been supplied to either the first storage chamber 11M or the second storage chamber 11N and passed through the interior thereof to the installation side. The ventilation switching mechanism (air supply passage 37, first intake valve 37d, second intake valve 37e, air return passage 38, first discharge valve 38d, second discharge valve 38e, first outside air ventilation passage, first ventilation shutter 39a, second outside air ventilation passage 40, second ventilation shutter 40a) switches between the first storage chamber 11M and the second storage chamber 11N that accommodates the condenser when one of the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34 functions as a condenser and the other functions as an evaporator. The ventilation states of the first storage chamber 11M and the second storage chamber 11N are switched so that one of them is in a first state in which air is allowed to circulate between the installation side of the indoor unit 12 and the indoor unit 12 via the air supply air duct 37 and the air return air duct 38 and the intake of outside air from outside the outdoor unit 11, and the other of the first storage chamber 11M and the second storage chamber 11N that accommodates the evaporator is in a second state in which air is prevented from circulating between the installation side and the outdoor air is allowed to be taken in.

[0135] With this configuration, for example, a cycle is repeatedly performed in which the second outdoor heat exchanger 32 in the first storage chamber 11M and the third outdoor heat exchanger 34 in the second storage chamber 11N alternate between functioning as a condenser and functioning as an evaporator. That is, by repeatedly performing a cycle in which the ventilation state is switched between the first state and the second state, it is possible to continuously and easily humidify the interior air W on the indoor unit 12 side, i.e., the air in the room R in which the indoor unit 12 is installed. Furthermore, in this case, it is only necessary to switch the usage states of the second outdoor heat exchanger 32 and the third outdoor heat exchanger 34, and no auxiliary parts such as adsorbents for retaining moisture for humidification are required. This makes it possible to provide an air conditioner 10 that can achieve efficient humidifying heating without requiring maintenance during operation.

[0136] In addition, in the third piping 53 of the air conditioning device 10, a heat generating mechanism 41 may be provided, for example, between the connection portion with the first piping 51 between the first four-way valve 25 and the indoor heat exchanger 42 and the second four-way valve 26.

[0137] With this configuration, for example, the temperature of the refrigerant supplied when the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 functions as a condenser can be further increased. As a result, frost formed on the surfaces of the second outdoor heat exchanger 32 or the third outdoor heat exchanger 34 when they function as evaporators can be more efficiently melted, the humidity in the first storage chamber 11M or the second storage chamber 11N can be efficiently increased, and the in-unit air W circulating between the indoor unit 12 side and the first storage chamber 11M or the second storage chamber 11N can be more efficiently humidified.

[0138] The air conditioning device 10 may also include, for example, a second pipe 52 between the first expansion valve 28 and the first outdoor heat exchanger 21, a fourth pipe 54 connected to a pipe between one end of the third pipe 53 and the second four-way valve 26, or a pipe between the other end of the third pipe 53 and the second four-way valve 26, and a fourth outdoor heat exchanger 36 provided on the fourth pipe 54.

[0139] According to this configuration, for example, during humidification heating operation or heating operation when the outdoor temperature is low, such as in winter, the fourth outdoor heat exchanger 36 functions as a condenser to perform heat exchange, thereby raising the ambient air temperature. The heated air can then be supplied to the first outdoor heat exchanger 21. This can contribute to suppressing frost formation on the first outdoor heat exchanger 21, which functions as an evaporator for humidification heating operation or heating operation. Meanwhile, during cooling operation when the outdoor temperature is high, such as in summer, the fourth outdoor heat exchanger 36 functions as an evaporator to perform heat exchange, thereby lowering the ambient air temperature. In this case, cooled air can be supplied to the first outdoor heat exchanger 21, which functions as a condenser for cooling operation. This can contribute to improving the heat exchange efficiency of the first outdoor heat exchanger 21. Furthermore, since the temperature around the first outdoor heat exchanger 21 can be lowered, it becomes possible to lower the temperature of the refrigerant supplied from the compressor 23 to the first outdoor heat exchanger 21, thereby reducing the workload of the compressor 23. In other words, this can contribute to energy-saving operation.

[0140] 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]

[0141] 10...air conditioner, 11...outdoor unit, 11M...first storage chamber, 11N...second storage chamber, 12...indoor unit, 13...refrigerant piping, 14...control device, 21...first outdoor heat exchanger, 22...outdoor blower fan, 23...compressor, 25...first four-way valve, 26...second four-way valve, 27...three-way valve, 28...first expansion valve, 29...second expansion valve, 30...third expansion valve, 31...flow control valve, 32...second outdoor heat exchanger, 33...first auxiliary fan, 34...third outdoor heat exchanger, 35...third 2 auxiliary fan, 36...fourth outdoor heat exchanger, 37...air supply duct, 37d...first suction valve, 37e...second suction valve, 38...air return duct, 38d...first discharge valve, 38e...second discharge valve, 39...first outdoor air vent duct, 39a...first ventilation shutter, 40...second outdoor air vent duct, 40a...second ventilation shutter, 41...heat generating mechanism, 42...indoor heat exchanger, 43...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 a first outdoor heat exchanger and an outdoor blower fan; a first pipe connecting the indoor heat exchanger and the first outdoor heat exchanger and through which a refrigerant flows; a second pipe connecting the first 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 first four-way valve provided in the first pipe and capable of changing the direction in which the refrigerant flows; a first expansion valve provided in the second pipe; a third pipe provided in the outdoor unit and connecting the first pipe between the suction port and the first four-way valve and the first pipe between the first four-way valve and the indoor heat exchanger; a second outdoor heat exchanger provided in the third pipe; a first accommodation chamber that accommodates the second outdoor heat exchanger and the first auxiliary fan; a third outdoor heat exchanger provided in the third pipe and connected in series to the second outdoor heat exchanger; a second accommodation chamber that accommodates the third outdoor heat exchanger and the second auxiliary fan; a second expansion valve provided in the third pipe between the second outdoor heat exchanger and the third outdoor heat exchanger; a second four-way valve provided in the third pipe and capable of changing the direction in which the refrigerant flows; an air supply duct that supplies air from the installation side of the indoor unit to either the first storage chamber or the second storage chamber; an air return duct that returns air that has been supplied to either the first storage chamber or the second storage chamber and passed through the interior thereof to the installation side; an airflow switching mechanism that switches the airflow states of the first storage chamber and the second storage chamber so that, when one of the second outdoor heat exchanger and the third outdoor heat exchanger functions as a condenser and the other functions as an evaporator, one of the first storage chamber and the second storage chamber that accommodates the condenser is in a first state that allows air to circulate between the first storage chamber and the second storage chamber and an installation side of the indoor unit via the air supply airflow path and the air return airflow path and inhibits the intake of outside air from outside the outdoor unit, and the other of the first storage chamber and the second storage chamber that accommodates the evaporator is in a second state that inhibits air to circulate between the first storage chamber and the installation side and allows the intake of outside air; An air conditioning device comprising:

2. a heat generating mechanism is provided in the third piping between a connection portion of the first piping between the first four-way valve and the indoor heat exchanger and the second four-way valve; The air conditioning apparatus according to claim 1.

3. a fourth pipe connected to the second pipe between the first expansion valve and the first outdoor heat exchanger, and to the pipe between one end of the third pipe and the second four-way valve, or to the pipe between the other end of the third pipe and the second four-way valve; a fourth outdoor heat exchanger provided in the fourth pipe; The air conditioning apparatus according to claim 1 or 2, comprising:

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