JP7785172B2 - air conditioner - Google Patents

Description

This disclosure relates to an air conditioner.

An air conditioner is known that includes an outdoor unit with an outdoor heat exchanger that functions as a condenser, an indoor unit with a first indoor heat exchanger that functions as a cooler and a second indoor heat exchanger that functions as a reheater, and a compressor that circulates refrigerant through the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. In this air conditioner, air cooled and dehumidified by the first indoor heat exchanger is heated by the second indoor heat exchanger, thereby individually adjusting the temperature and humidity of the air blown out from the indoor unit into the space to be air-conditioned. Such an air conditioner is described, for example, in JP 2002-89998 A (Patent Document 1).

Japanese Patent Application Laid-Open No. 2002-89998

However, the air conditioner described in the above publication uses only one four-way valve as the refrigerant flow switching mechanism. Therefore, when cooling-dominated operation and heating-dominated operation are performed in accordance with the two switching states of the four-way valve, the direction of refrigerant flow through the indoor unit is reversed in cooling-dominated operation and heating-dominated operation. Therefore, the indoor heat exchanger functioning as a cooler and the indoor heat exchanger functioning as a reheater are interchanged in cooling-dominated operation and heating-dominated operation. As a result, in either cooling-dominated operation or heating-dominated operation, air heated in the reheater is cooled in the cooler, preventing sufficient dehumidification.

This disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an air conditioner that can ensure the direction of refrigerant flowing through the reheater and cooler is the same in both cooling-dominated operation and heating-dominated operation.

The air conditioner of the present disclosure includes a refrigerant circuit and a blower. The refrigerant circuit has a compressor, a six-way valve, an outdoor heat exchanger, a reheater, a first expansion valve, and a cooler, and is configured to circulate a refrigerant. The blower is configured to be able to blow air to the reheater and the cooler. The six-way valve is configured to be switchable between a first switching state and a second switching state. In the first switching state, the six-way valve is configured to switch the refrigerant circuit so that the refrigerant flows in the following order: compressor, six-way valve, outdoor heat exchanger, six-way valve, reheater, first expansion valve, six-way valve, and cooler. In the second switching state, the six-way valve is configured to switch the refrigerant circuit so that the refrigerant flows in the following order: compressor, six-way valve, reheater, first expansion valve, six-way valve, outdoor heat exchanger, six-way valve, and cooler. The reheater and the cooler are configured so that, in both the first switching state and the second switching state, the air blown by the blower passes through the cooler and then passes through the reheater.

In the air conditioner of the present disclosure, the refrigerant flow switching mechanism is configured to switch the refrigerant circuit so that the refrigerant flows through the reheater and then the cooler in either the first switching state or the second switching state. This allows the direction of refrigerant flow through the reheater and the cooler to be the same in both cooling-dominated operation and heating-dominated operation.

1 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to Embodiment 1. FIG. 1 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to Embodiment 1. FIG. 1 is a schematic diagram of a first switching state of a rotary six-way valve of an air conditioner according to Embodiment 1. FIG. 4 is a schematic diagram of a second switching state of the rotary six-way valve of the air conditioner according to the first embodiment. FIG. 1 is a schematic diagram of a first switching state of a sliding six-way valve of an air conditioner according to Embodiment 1. FIG. 4 is a schematic diagram of a second switching state of the sliding six-way valve of the air conditioner according to the first embodiment. FIG. FIG. 10 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to a second embodiment. FIG. 10 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to a second embodiment. FIG. 11 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to a third embodiment. FIG. 11 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to a third embodiment. FIG. 10 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to a fourth embodiment. FIG. 10 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to a fourth embodiment. FIG. 10 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to a fifth embodiment. FIG. 10 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to a fifth embodiment. FIG. 13 is a refrigerant circuit diagram of a cooling-dominated operation of an air conditioner according to a sixth embodiment. FIG. 13 is a refrigerant circuit diagram of a heating-dominated operation of an air conditioner according to a sixth embodiment. FIG. 13 is a perspective view of a reheater and a cooler of an air conditioner according to a seventh embodiment.

The following describes the embodiments with reference to the drawings. Note that, in the following, the same or corresponding parts are given the same reference numerals and their descriptions will not be repeated.

Embodiment 1.
The configuration of an air conditioner 100 according to the first embodiment will be described with reference to FIG.

<Device configuration>
Figure 1 is a refrigerant circuit diagram of an air conditioner 100 pertaining to Embodiment 1. As shown in Figure 1, the air conditioner 100 includes a refrigerant circuit RC, an outdoor blower 14, an air duct 31, a blower 32, and a control device CD. The refrigerant circuit RC includes a first pipe 1, a second pipe 2, a third pipe 3, a fourth pipe 4, a fifth pipe 5, a sixth pipe 6, a compressor 11, a six-way valve 12, an outdoor heat exchanger 13, a reheater 21, a cooler 22, and a first expansion valve 23.

In the refrigerant circuit RC, the compressor 11, six-way valve 12, outdoor heat exchanger 13, reheater 21, cooler 22, and first expansion valve 23 are connected by the first pipe 1, second pipe 2, third pipe 3, fourth pipe 4, fifth pipe 5, and sixth pipe 6.

The first pipe 1 connects the compressor 11 and the six-way valve 12. The second pipe 2 connects the six-way valve 12 and the outdoor heat exchanger 13. The third pipe 3 connects the outdoor heat exchanger 13 and the six-way valve 12. The fourth pipe 4 connects the six-way valve 12 and the reheater 21. The fifth pipe 5 connects the reheater 21 and the six-way valve 12 via the first expansion valve 23. The sixth pipe 6 connects the six-way valve 12 and the cooler 22.

In the first switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22.

In the second switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, third pipe 3, outdoor heat exchanger 13, second pipe 2, six-way valve 12, sixth pipe 6, and cooler 22.

The refrigerant circuit RC is configured to circulate a refrigerant. The refrigerant is a mixed refrigerant. A mixed refrigerant is a mixture of two or more types of refrigerants. However, the refrigerant may also be a single refrigerant.

The air conditioner 100 comprises an outdoor unit 10 and an indoor unit 20. The outdoor unit 10 and the indoor unit 20 are connected by a second pipe 2 and a third pipe 3. The outdoor unit 10 has an outdoor heat exchanger 13 and an outdoor blower 14. The outdoor heat exchanger 13 and the outdoor blower 14 are housed in the outdoor unit 10. The indoor unit 20 has a compressor 11, a six-way valve 12, a reheater 21, a cooler 22, a first expansion valve 23, an air duct 31, a blower 32, and a control device CD. The compressor 11, the six-way valve 12, the reheater 21, the cooler 22, the first expansion valve 23, the blower 32, and the control device CD are housed in the indoor unit 20. The indoor unit 20 has an air duct 31.

The compressor 11 is configured to compress the refrigerant. The compressor 11 is configured to compress the refrigerant that it draws in and then discharge it. The compressor 11 is configured, for example, to have a variable capacity. The compressor 11 is configured, for example, so that its capacity can be changed by adjusting the rotation speed of the compressor 11 based on instructions from the control device CD.

The six-way valve 12 is configured to be switchable between a first switching state and a second switching state. The six-way valve 12 is configured to be switchable between the first switching state and the second switching state, for example, based on an instruction from the control device CD. In the first switching state, the six-way valve 12 is configured to switch the refrigerant circuit RC so that the refrigerant flows in the following order: compressor 11, six-way valve 12, outdoor heat exchanger 13, six-way valve 12, reheater 21, first expansion valve 23, six-way valve 12, and cooler 22. The six-way valve 12 is in the first switching state during cooling-dominated operation.

In the second switching state, the six-way valve 12 is configured to switch the refrigerant circuit RC so that the refrigerant flows in the following order: compressor 11, six-way valve 12, reheater 21, first expansion valve 23, six-way valve 12, outdoor heat exchanger 13, six-way valve 12, and cooler 22. The six-way valve 12 is in the second switching state during heating-dominated operation.

Each of the six connection ports (first connection port P1 to sixth connection port P6) of the six-way valve 12 is connected to the first pipe 1, second pipe 2, third pipe 3, fourth pipe 4, fifth pipe 5, and sixth pipe 6, respectively. The first connection port P1 is connected to the second pipe 2. The second connection port P2 is connected to the sixth pipe 6. The third connection port P3 is connected to the fifth pipe 5. The fourth connection port P4 is connected to the third pipe 3. The fifth connection port P5 is connected to the fourth pipe 4. The sixth connection port P6 is connected to the first pipe 1.

When the six-way valve 12 is in the first switching state, a refrigerant circuit RC is formed, passing through the compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22, and then back to the compressor 11. When the six-way valve 12 is in the first switching state, the sixth connection port P6 is connected to the first connection port P1, the third connection port P3 is connected to the second connection port P2, and the fifth connection port P5 is connected to the fourth connection port P4.

When the six-way valve 12 is in the second switching state, a refrigerant circuit RC is formed, passing through the compressor 11, first pipe 1, six-way valve 12, fourth pipe 4, reheater 21, first expansion valve 23, fifth pipe 5, six-way valve 12, third pipe 3, outdoor heat exchanger 13, second pipe 2, six-way valve 12, sixth pipe 6, and cooler 22, and then back to the compressor 11. When the six-way valve 12 is in the second switching state, the second connection port P2 is connected to the first connection port P1. The fourth connection port P4 is connected to the third connection port P3. The sixth connection port P6 is connected to the fifth connection port P5.

The outdoor heat exchanger 13 is configured to exchange heat between the refrigerant flowing inside the outdoor heat exchanger 13 and the air flowing outside the outdoor heat exchanger 13. The outdoor heat exchanger 13 is configured to function as a condenser that condenses the refrigerant during cooling-dominated operation. The outdoor heat exchanger 13 is configured to function as an evaporator that evaporates the refrigerant during heating-dominated operation. The outdoor heat exchanger 13 is, for example, a fin-and-tube heat exchanger having multiple fins and heat transfer tubes that pass through the multiple fins.

The control device CD is configured to perform calculations, instructions, etc. to control each device of the air conditioner 100. The control device CD is electrically connected to the compressor 11, six-way valve 12, first expansion valve 23, blower 32, etc., and is configured to control the operation of these devices.

The reheater 21 is configured to exchange heat between the refrigerant flowing inside the reheater 21 and the air flowing outside the reheater 21. The reheater 21 is configured to function as a condenser that condenses the refrigerant in cooling-dominated operation and heating-dominated operation. The reheater 21 is, for example, a fin-and-tube heat exchanger having multiple fins and heat transfer tubes that pass through the multiple fins.

The cooler 22 is configured to exchange heat between the refrigerant flowing inside the cooler 22 and the air flowing outside the cooler 22. The cooler 22 is configured to function as an evaporator that evaporates the refrigerant in cooling-dominated operation and heating-dominated operation. The cooler 22 is, for example, a fin-and-tube heat exchanger having multiple fins and heat transfer tubes that pass through the multiple fins.

The first expansion valve 23 is configured to reduce the pressure of the refrigerant condensed in the condenser by expanding it. The first expansion valve 23 is configured to reduce the pressure of the refrigerant condensed by the reheater 21 in cooling-dominated operation and heating-dominated operation. The first expansion valve 23 is, for example, an electromagnetic expansion valve. The first expansion valve 23 is configured, for example, to change the amount of pressure reduction by adjusting the opening degree of the first expansion valve 23 based on instructions from the control device CD.

Air duct 31 is provided in the housing of the indoor unit 20. Reheater 21 and cooler 22 are arranged within air duct 31. Blower 32 is configured to be able to blow air to reheater 21 and cooler 22. Reheater 21 and cooler 22 are arranged side by side in the direction of the air flow blown by blower 32. Reheater 21 is arranged downwind of cooler 22 in the flow of air blown by blower 32. In air duct 31, cooler 22 is arranged upstream of reheater 21.

The reheater 21 and the cooler 22 share the air passage 31 and the blower 32. The reheater 21 and the cooler 22 are configured so that, in either the first switching state or the second switching state, the air blown by the blower 32 passes through the cooler 22 before passing through the reheater 21. When the blower 32 is operating, the reheater 21 and the cooler 22 are configured so that the air passes through the cooler 22 before passing through the reheater 21, regardless of whether the six-way valve 12 is in the first switching state or the second switching state.

The reheater 21 and the cooler 22 may be configured so that the refrigerant flows countercurrently to the air flow. Both the reheater 21 and the cooler 22 have a heat transfer tube flow path configuration in which the air and refrigerant flow countercurrently. The reheater 21 and the cooler 22 each have an upwind heat transfer tube and a downwind heat transfer tube. The upwind heat transfer tube is connected to the downwind heat transfer tube. In cooling-dominated operation and heating-dominated operation, the refrigerant flows from the downwind heat transfer tube to the upwind heat transfer tube. In both cooling-dominated operation and heating-dominated operation, the refrigerant flowing inside the heat transfer tubes of the reheater 21 and the cooler 22 flows countercurrently to the air flowing outside the heat transfer tubes.

Next, the operation of the air conditioner 100 according to the first embodiment will be described.
<Cooling-based operation>
First, referring to Figure 1, the cooling-dominated operation of the air conditioner 100 according to embodiment 1 will be described. Cooling-dominated operation is an operation in which the amount of air cooled in the cooler 22 is greater than the amount of air heated in the reheater 21, and the outdoor heat exchanger 13 functions as a condenser, so that excess heat released by the heat pump is released to the outside air. In cooling-dominated operation, the air that has passed through the reheater 21 has a lower temperature and a lower moisture content than the air before passing through the cooler 22.

In cooling-dominated operation, the six-way valve 12 is switched to the first switching state, as shown by the solid line in Figure 1. Vapor refrigerant compressed to high temperature and high pressure by the compressor 11 flows out into the first pipe 1, passes through the six-way valve 12, and flows into the outdoor heat exchanger 13 via the second pipe 2. The outdoor heat exchanger 13 functions as a condenser. The high-temperature, high-pressure vapor refrigerant releases heat to the outdoor air introduced into the outdoor heat exchanger 13 by the outdoor blower 14. As a result, the high-temperature, high-pressure vapor refrigerant condenses and becomes a high-temperature, high-pressure, two-phase gas-liquid refrigerant.

The high-temperature, high-pressure, two-phase gas-liquid refrigerant flows out into the third pipe 3, passes through the six-way valve 12, and flows into the reheater 21 via the fourth pipe 4. The reheater 21 functions as a condenser. The high-temperature, high-pressure, two-phase gas-liquid refrigerant dissipates heat to the air introduced into the reheater 21 by the blower 32. As a result, the high-temperature, high-pressure, two-phase gas-liquid refrigerant condenses into high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows into the first expansion valve 23.

This high-pressure liquid refrigerant expands and is reduced in pressure in the first expansion valve 23, becoming a low-temperature, low-pressure, two-phase gas-liquid refrigerant. This low-temperature, low-pressure, two-phase gas-liquid refrigerant flows out into the fifth pipe 5, passes through the six-way valve 12, and flows into the cooler 22 via the sixth pipe 6. The cooler 22 functions as an evaporator. By absorbing heat from the air introduced into the cooler 22 by the blower 32, the low-temperature, low-pressure, two-phase gas-liquid refrigerant evaporates and becomes a low-pressure vapor refrigerant. The low-pressure vapor refrigerant is then drawn into the compressor 11. In cooling-dominated operation, the refrigerant subsequently circulates through the refrigerant circuit RC following a similar process.

The reheater 21 and cooler 22 share the air duct 31 and blower 32. Air guided through the air duct 31 by the blower 32 is first cooled and dehumidified by passing through the cooler 22. This lowers the air temperature and reduces the moisture content of the air. After passing through the cooler 22, the air is guided into the air duct 31 and heated by passing through the reheater 21. This increases the air temperature. Note that humidification is not generally performed in the reheater 21, so the moisture content of the air remains the same before and after passing through the reheater 21. After passing through the reheater 21, the air is guided into the air duct 31 and blown out into the space to be air-conditioned.

After being cooled and dehumidified in the cooler 22, the air is heated as needed in the reheater 21, allowing the amount of dehumidification and the air temperature to be adjusted independently. This allows air at the temperature and humidity set by the user to be supplied to the space to be air-conditioned.

<Heating-dominant operation>
Next, the heating-dominated operation of the air conditioner 100 according to Embodiment 1 will be described with reference to Figure 2. Heating-dominated operation is an operation in which the amount of air heated in the reheater 21 is greater than the amount of air cooled in the cooler 22, and the outdoor heat exchanger 13 functions as an evaporator, so that surplus cold energy from the heat pump is released to the outside air. In heating-dominated operation, the air that has passed through the reheater 21 has a higher temperature and a lower moisture content than the air before passing through the cooler 22.

In heating-dominant operation, the six-way valve 12 is switched to the second switching state, as shown by the solid line in Figure 2. The vapor refrigerant compressed to a high temperature and high pressure by the compressor 11 flows into the first pipe 1, passes through the six-way valve 12, and flows into the reheater 21 via the fourth pipe 4. The reheater 21 functions as a condenser. The high-temperature, high-pressure vapor refrigerant releases heat to the air introduced into the reheater 21 by the blower 32. As a result, the high-temperature, high-pressure vapor refrigerant condenses and becomes high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows into the first expansion valve 23.

This high-pressure liquid refrigerant expands and is reduced in pressure in the first expansion valve 23, becoming a low-temperature, low-pressure, two-phase gas-liquid refrigerant. This low-temperature, low-pressure, two-phase gas-liquid refrigerant flows out into the fifth pipe 5, passes through the six-way valve 12, and flows into the outdoor heat exchanger 13 via the third pipe 3. The outdoor heat exchanger 13 functions as an evaporator. The low-temperature, low-pressure, two-phase gas-liquid refrigerant partially evaporates by absorbing heat from the outdoor air introduced into the outdoor heat exchanger 13 by the outdoor blower 14. The low-temperature, low-pressure, two-phase gas-liquid refrigerant then flows into the six-way valve 12 via the second pipe 2 and into the cooler 22 via the sixth pipe 6.

The cooler 22 functions as an evaporator. By absorbing heat from the air introduced into the cooler 22 by the blower 32, the low-temperature, low-pressure, gas-liquid two-phase refrigerant evaporates and becomes low-pressure vapor refrigerant. This low-pressure vapor refrigerant is drawn into the compressor 11. In heating-dominated operation, the refrigerant then circulates through the refrigerant circuit RC in the same manner.

The air guided through the air duct 31 by the blower 32 is cooled and dehumidified in the cooler 22, as in cooling-dominated operation, and then heated in the reheater 21 before being blown into the space to be air-conditioned. Therefore, the amount of dehumidification and the air temperature can be adjusted independently. This allows air at the temperature and humidity set by the user to be supplied to the space to be air-conditioned.

Next, the effects of the air conditioner 100 according to the first embodiment will be described.
In the air conditioner according to the first embodiment, the six-way valve 12 is configured to switch the refrigerant circuit RC so that the refrigerant flows through the reheater 21 and the cooler 22 in that order in either the first switching state or the second switching state. The six-way valve 12 is in the first switching state in cooling-dominated operation and in the second switching state in heating-dominated operation. This allows the direction of refrigerant flow through the reheater 21 and the cooler 22 to be the same in both cooling-dominated operation and heating-dominated operation. Therefore, in both cooling-dominated operation and heating-dominated operation, the air cooled and dehumidified in the cooler 22 can be heated in the reheater 21. This allows air at a temperature and humidity set by the user to be supplied to the space to be air-conditioned.

Furthermore, the reheater 21 and cooler 22 are configured so that, in both the first switching state and the second switching state, the air blown by the blower 32 passes through the cooler 22 before passing through the reheater 21. Therefore, in both cooling-dominated operation and heating-dominated operation, the air can be cooled and dehumidified before being reheated. Therefore, sufficient dehumidification can be achieved in both cooling-dominated operation and heating-dominated operation.

In particular, since sufficient dehumidification can be achieved during heating-dominated operation, heating-dominated operation can be utilized to dry and dehumidify the space to be air-conditioned. Therefore, the air conditioner 100 according to embodiment 1 can also be used to dry food and ingredients.

In addition, during cooling-dominated operation, refrigerant that has passed through the outdoor heat exchanger 13 flows through the reheater 21. During heating-dominated operation, refrigerant that has passed through the outdoor heat exchanger 13 flows through the cooler 22. Therefore, the amount of heat exchanged by the refrigerant can be easily adjusted by adjusting the effective heat transfer area of the outdoor heat exchanger 13. In addition, the amount of heat exchanged by the refrigerant can be easily adjusted by adjusting the rotation speed of the outdoor blower 14. Since refrigerant whose heat quantity (internal energy) has been adjusted in the outdoor heat exchanger 13 can be supplied to the reheater 21 or the cooler 22, the amount of heat exchanged in the reheater 21 or the cooler 22 can be continuously adjusted. Therefore, the air conditioner 100 can be operated with a stable discharge temperature from the indoor unit 20.

According to the air conditioner of embodiment 1, in the first switching state, the refrigerant circuit RC is configured so that refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22. In the second switching state, the refrigerant circuit RC is configured so that refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, third pipe 3, outdoor heat exchanger 13, second pipe 2, six-way valve 12, sixth pipe 6, and cooler 22. Therefore, in either the first switching state or the second switching state, the refrigerant can flow through the refrigerant circuit RC in the order of the reheater 21 and the cooler 22 .

In the air conditioner 100 according to embodiment 1, the refrigerant is a mixed refrigerant. Mixed refrigerants, which are mixtures of two or more types of refrigerants, are generally non-azeotropic, and therefore the temperature during the gas-liquid phase change is not constant. As a result, a temperature gradient occurs in the heat exchanger as the mixed refrigerant changes phase. This necessitates optimal design of the heat exchanger. In the air conditioner 100 according to embodiment 1, the reheater 21 and cooler 22 can be specially designed, making it possible to achieve a high-performance air conditioner 100 even when using a mixed refrigerant.

In the air conditioner 100 according to embodiment 1, the reheater 21 and the cooler 22 are configured so that the refrigerant flows countercurrently to the air flow. This allows the temperature gradient of the mixed refrigerant within the heat exchanger to be utilized, thereby reducing the heat exchange temperature difference between the air and the refrigerant. This allows the air conditioner 100 to operate at high performance.

Since the temperature of non-azeotropic refrigerants rises as the refrigerant evaporates, by configuring the air and refrigerant to flow in counter-current fashion in the cooler 22, which functions as an evaporator, the temperature increase in the direction of refrigerant flow and the temperature decrease in the direction of air flow interact with each other, reducing the heat exchange temperature difference between the air and refrigerant throughout the entire cooler 22.

In addition, since the temperature of non-azeotropic refrigerants decreases as they condense, by configuring the air and refrigerant to flow in countercurrent fashion in the reheater 21, which functions as a condenser, the temperature decrease in the direction of refrigerant flow and the temperature increase in the direction of air flow interact with each other, reducing the heat exchange temperature difference between the air and refrigerant throughout the entire reheater 21.

The position of the blower 32 is not limited to being upstream of the air duct 31 of the cooler 22 as shown in Figures 1 and 2. The position of the blower 32 may be between the cooler 22 and the reheater 21 in the air duct 31, or may be downstream of the air duct 31 of the reheater 21.

Also, with reference to Figures 3 and 4, the six-way valve 12 may be of a rotary type configuration. Figure 3 is a schematic diagram of the rotary six-way valve 12 in a first switching state. Figure 4 is a schematic diagram of the rotary six-way valve 12 in a second switching state. The rotary six-way valve 12 has a valve seat 12a and a valve element 12b configured to be rotatable relative to the valve seat 12a. By rotating the valve element 12b relative to the valve seat 12a, the flow path is switched between the first switching state and the second switching state.

Also, with reference to Figures 5 and 6, the six-way valve 12 may have a sliding configuration. Figure 5 is a schematic diagram of the sliding six-way valve 12 in a first switching state. Figure 6 is a schematic diagram of the sliding six-way valve 12 in a second switching state. The sliding six-way valve 12 has a valve seat 12a and a valve body 12b configured to be slidable relative to the valve seat 12a. The flow path is switched between the first switching state and the second switching state by the valve body 12b sliding relative to the valve seat 12a.

Embodiment 2.
Unless otherwise specified, the air conditioner 100 according to the second embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the first embodiment.

The configuration of the air conditioner 100 according to embodiment 2 will be described with reference to Figure 7. Figure 7 is a refrigerant circuit diagram of the air conditioner 100 according to embodiment 2. Compared to the air conditioner 100 according to embodiment 1, the air conditioner 100 according to embodiment 2 has a configuration in which the connection positions of the fifth pipe 5 and the sixth pipe 6 relative to the six-way valve 12 are swapped.

Each of the six connection ports (first connection port P1 to sixth connection port P6) of the six-way valve 12 is connected to the first pipe 1, second pipe 2, third pipe 3, fourth pipe 4, fifth pipe 5, and sixth pipe 6, respectively. The first connection port P1 is connected to the second pipe 2. The second connection port P2 is connected to the fifth pipe 5. The third connection port P3 is connected to the sixth pipe 6. The fourth connection port P4 is connected to the third pipe 3. The fifth connection port P5 is connected to the fourth pipe 4. The sixth connection port P6 is connected to the first pipe 1.

In the first switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22.

In the second switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, sixth pipe 6, and cooler 22.

Next, with reference to Figures 7 and 8, the operation of the air conditioner 100 relating to embodiment 2 will be explained.

The operation of the air conditioner 100 according to embodiment 2 is basically the same as that according to embodiment 1. Referring to Figure 7, in cooling-dominated operation of the air conditioner 100 according to embodiment 2, the refrigerant flows through the refrigerant circuit RC via the compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22, before returning to the compressor 11.

Referring to Figure 8, in heating-dominated operation of the air conditioner 100 of embodiment 2, the refrigerant flows through the refrigerant circuit RC via the compressor 11, the first pipe 1, the six-way valve 12, the fourth pipe 4, the reheater 21, the first expansion valve 23, the fifth pipe 5, the six-way valve 12, the second pipe 2, the outdoor heat exchanger 13, the third pipe 3, the six-way valve 12, the sixth pipe 6, and the cooler 22, before returning to the compressor 11.

Next, the effects of the air conditioner 100 according to the second embodiment will be described.
According to the air conditioner 100 of the second embodiment, in the first switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22. In the second switching state, the refrigerant circuit RC is configured so that the refrigerant flows in the following order: compressor 11, first pipe 1, six-way valve 12, fourth pipe 4, reheater 21, fifth pipe 5, first expansion valve 23, fifth pipe 5, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, sixth pipe 6, and cooler 22. Therefore, in either the first switching state or the second switching state, the refrigerant can flow through the refrigerant circuit RC in the order of the reheater 21 and the cooler 22 .

In the air conditioner 100 according to embodiment 2, the air flow direction guided by the outdoor blower 14 to the outdoor heat exchanger 13 is the same in both cooling-dominated operation and heating-dominated operation. By making the refrigerant flow direction inside the outdoor heat exchanger 13 the same in both the first and second switching states of the six-way valve 12, heat exchange between the air and the refrigerant in the outdoor heat exchanger 13 can be counterflow in both cooling-dominated operation and heating-dominated operation. Because the temperatures of the air and the refrigerant change in accordance with the heat exchange, counterflow heat exchange can reduce the heat exchange temperature difference between the air and the refrigerant across the entire outdoor heat exchanger 13 compared to parallel flow heat exchange. This allows the performance and power consumption of the air conditioner 100 to be optimized.

In particular, in recent years, many mixtures of high-performance refrigerants with refrigerants that have a low global warming potential or a slow combustion rate have been proposed in order to reduce the global warming impact when refrigerant leaks from the air conditioner 100 and to reduce the refrigerant combustion rate when refrigerant leaks.

Mixed refrigerants, which are mixtures of two or more refrigerants, generally have non-azeotropic properties, in which temperature changes occur during the phase change processes of evaporation and condensation. The countercurrent heat exchange method in the outdoor heat exchanger 13 of embodiment 2 is particularly effective when the air conditioner 100 contains a mixed refrigerant, which is a mixture of two or more refrigerants.

Since the temperature of non-azeotropic refrigerants decreases as they condense, in cooling-dominated operation, by having the air and refrigerant flow in countercurrent directions in the outdoor heat exchanger 13, which functions as a condenser, the temperature decrease in the direction of refrigerant flow and the temperature increase in the direction of air flow interact with each other. This reduces the heat exchange temperature difference between the air and refrigerant throughout the entire outdoor heat exchanger 13.

In addition, since the temperature of non-azeotropic refrigerants rises as the refrigerant evaporates, by making the air and refrigerant flow countercurrently in the outdoor heat exchanger 13, which functions as an evaporator during heating-dominated operation, the temperature rise in the direction of refrigerant flow and the temperature drop in the direction of air flow interact with each other. This reduces the heat exchange temperature difference between the air and refrigerant throughout the entire outdoor heat exchanger 13.

Embodiment 3.
Unless otherwise specified, the air conditioner 100 according to the third embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the first embodiment.

The configuration of the air conditioner 100 according to embodiment 3 will be described with reference to Figure 9. Figure 9 is a refrigerant circuit diagram of the air conditioner 100 according to embodiment 3. The air conditioner 100 according to embodiment 3 differs from the air conditioner 100 according to embodiment 1 in that it has a liquid receiver 24.

In the air conditioner 100 according to embodiment 3, the refrigerant circuit RC has a liquid receiver 24. The liquid receiver 24 is arranged in the refrigerant circuit RC between the reheater 21 and the first expansion valve 23. The liquid receiver 24 is configured to store refrigerant.

Next, with reference to Figures 9 and 10, the operation of the air conditioner 100 relating to embodiment 3 will be explained.

The operation of the air conditioner 100 according to embodiment 3 is basically the same as that according to embodiment 1. Referring to Figure 9, in cooling-dominated operation of the air conditioner 100 according to embodiment 3, the refrigerant flows through the refrigerant circuit RC via the compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, receiver 24, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22, before returning to the compressor 11.

Referring to Figure 10, in heating-dominated operation of the air conditioner 100 of embodiment 3, the refrigerant flows through the refrigerant circuit RC via the compressor 11, the first pipe 1, the six-way valve 12, the fourth pipe 4, the reheater 21, the receiver 24, the first expansion valve 23, the fifth pipe 5, the six-way valve 12, the third pipe 3, the outdoor heat exchanger 13, the second pipe 2, the six-way valve 12, the sixth pipe 6, and the cooler 22, before returning to the compressor 11.

Next, the effects of the air conditioner 100 according to the third embodiment will be described.
In cooling-dominated operation, a decrease in the amount of heat dissipated in the outdoor heat exchanger 13 reduces the amount of liquid refrigerant remaining inside the outdoor heat exchanger 13. In an air conditioner 100 that does not have a refrigerant amount adjustment mechanism, the amount of refrigerant charged becomes excessive relative to the appropriate refrigerant amount for that operation, which raises concerns about operational problems due to excessive increases in the compressor discharge refrigerant temperature or pressure.

In the air conditioner 100 according to embodiment 3, the receiver 24 is arranged in the refrigerant circuit RC between the reheater 21 and the first expansion valve 23. This makes it possible to achieve an optimum operating point for the compressor 11 by adjusting the amount of available refrigerant in the air conditioner 100.

In addition, to prevent refrigerant flow noise, it is desirable to supply liquid refrigerant to the first expansion valve 23. By placing the receiver 24 upstream of the refrigerant flow relative to the first expansion valve 23, the refrigerant at the inlet of the first expansion valve 23 can be stably maintained in a liquid state.

Embodiment 4.
Unless otherwise specified, the air conditioner 100 according to the fourth embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the third embodiment.

The configuration of the air conditioner 100 according to embodiment 4 will be described with reference to Figure 11. Figure 11 is a refrigerant circuit diagram of the air conditioner 100 according to embodiment 4. The air conditioner 100 according to embodiment 4 differs from the air conditioner 100 according to embodiment 3 in that it has a second expansion valve 25.

In the air conditioner 100 according to embodiment 4, the refrigerant circuit RC has a second expansion valve 25. The second expansion valve 25 is arranged in the refrigerant circuit RC between the reheater 21 and the receiver 24. The second expansion valve 25 is configured to have an adjustable opening.

Next, with reference to Figures 11 and 12, the operation of the air conditioner 100 relating to embodiment 4 will be explained.

The operation of the air conditioner 100 according to embodiment 4 is basically the same as that according to embodiment 3. Referring to Figure 11, in cooling-dominated operation of the air conditioner 100 according to embodiment 4, the refrigerant flows through the refrigerant circuit RC via the compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, second expansion valve 25, receiver 24, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22, before returning to the compressor 11.

Referring to Figure 12, in heating-dominated operation of the air conditioner 100 according to embodiment 4, the refrigerant flows through the refrigerant circuit RC via the compressor 11, the first pipe 1, the six-way valve 12, the fourth pipe 4, the reheater 21, the second expansion valve 25, the receiver 24, the first expansion valve 23, the fifth pipe 5, the six-way valve 12, the third pipe 3, the outdoor heat exchanger 13, the second pipe 2, the six-way valve 12, the sixth pipe 6, and the cooler 22, before returning to the compressor 11.

Next, the effects of the air conditioner 100 according to the fourth embodiment will be described.
In the air conditioner 100 according to the fourth embodiment, the second expansion valve 25 is disposed in the refrigerant circuit RC between the reheater 21 and the receiver 24. The refrigerant pressure inside the receiver 24 can be adjusted by adjusting the opening degree of the second expansion valve 25. This makes it possible to actively adjust the amount of liquid refrigerant stored inside the receiver 24, compared to the third embodiment. Therefore, the air conditioner 100 can be operated more stably.

In addition, in embodiments 1 to 4, in order to stably supply liquid refrigerant to the first expansion valve 23 or the second expansion valve 25, it is preferable that the refrigerant inlet of the reheater 21 be positioned higher in the direction of gravity than the refrigerant outlet. In other words, the reheater 21 has a refrigerant inlet and a refrigerant outlet. The refrigerant inlet of the reheater 21 is positioned higher in the direction of gravity than the refrigerant outlet.

In this configuration, liquid refrigerant remaining in the reheater 21 is gradually discharged due to gravity, so the inlet refrigerant at the first expansion valve 23 or the second expansion valve 25 can be kept in a liquid state. Therefore, the air conditioner 100 can be operated stably.

Embodiment 5.
Unless otherwise specified, the air conditioner 100 according to the fifth embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the second embodiment.

The configuration of the air conditioner 100 according to embodiment 5 will be described with reference to Figure 13. Figure 13 is a refrigerant circuit diagram of the air conditioner 100 according to embodiment 5. The air conditioner 100 according to embodiment 5 differs from the air conditioner 100 according to embodiment 2 in terms of the outdoor heat exchanger 13.

The refrigerant circuit RC has a first refrigerant shut-off mechanism 15 and a second refrigerant shut-off mechanism 16. The first refrigerant shut-off mechanism 15 and the second refrigerant shut-off mechanism 16 are, for example, solenoid valves.

The outdoor heat exchanger 13 has a first heat exchange section 13a and a second heat exchange section 13b. The first heat exchange section 13a and the second heat exchange section 13b are arranged in parallel with each other in the refrigerant circuit RC. The first heat exchange section 13a has a larger internal volume than the second heat exchange section 13b. The first refrigerant closing mechanism 15 is connected to the inlet of the first heat exchange section 13a. The second refrigerant closing mechanism 16 is connected to the outlet of the first heat exchange section 13a.

The refrigerant circuit RC also has a bypass circuit 17. The bypass circuit 17 has a bypass pipe 17a and a flow rate adjustment mechanism 17b. The bypass pipe 17a is connected to the second pipe 2 and the third pipe 3. The flow rate adjustment mechanism 17b is configured to be able to adjust its opening. The flow rate adjustment mechanism 17b is configured to be able to adjust the flow rate of the refrigerant flowing through the bypass circuit 17. The flow rate adjustment mechanism 17b is, for example, a solenoid valve. The bypass circuit 17 is arranged in parallel with the outdoor heat exchanger 13 in the refrigerant circuit RC. The bypass circuit 17 is arranged between the six-way valve 12 and the outdoor heat exchanger 13 in the refrigerant circuit RC.

The operation of the air conditioner 100 according to embodiment 5 is basically the same as that according to embodiment 1. Referring to Figure 13, in cooling-dominated operation of the air conditioner 100 according to embodiment 5, the refrigerant flows through the refrigerant circuit RC via the compressor 11, first pipe 1, six-way valve 12, second pipe 2, outdoor heat exchanger 13 and bypass circuit 17, third pipe 3, six-way valve 12, fourth pipe 4, reheater 21, first expansion valve 23, fifth pipe 5, six-way valve 12, sixth pipe 6, and cooler 22, before returning to the compressor 11.

Referring to Figure 14, in heating-dominated operation of the air conditioner 100 according to embodiment 5, the refrigerant flows through the refrigerant circuit RC via the compressor 11, the first pipe 1, the six-way valve 12, the fourth pipe 4, the reheater 21, the first expansion valve 23, the fifth pipe 5, the six-way valve 12, the second pipe 2, the outdoor heat exchanger 13, the bypass circuit 17, the third pipe 3, the six-way valve 12, the sixth pipe 6, and the cooler 22, before returning to the compressor 11.

Next, the effects of the air conditioner 100 according to the fifth embodiment will be described.
The amount of heat released by condensation and the amount of heat received by evaporation in the outdoor heat exchanger 13 can be adjusted by reducing the rotation speed of the outdoor blower 14 to reduce the volume of outdoor air introduced into the outdoor heat exchanger 13. Furthermore, the first heat exchange section 13a and the second heat exchange section 13b of the outdoor heat exchanger 13 are arranged in parallel with each other in the refrigerant circuit RC. This blocks the flow of refrigerant in a portion of the outdoor heat exchanger 13, thereby further reducing the amount of heat exchanged in the outdoor heat exchanger 13. This therefore widens the stable adjustment range of the heat exchange amounts in the reheater 21 and the cooler 22.

In addition, by circulating refrigerant through the bypass circuit 17 and not through the outdoor heat exchanger 13, the amount of heat exchanged in the outdoor heat exchanger 13 can be finely adjusted. This allows the amount of heat exchanged in the reheater 21 to be increased during cooling-dominated operation. Furthermore, the amount of heat exchanged in the cooler 22 can be increased during heating-dominated operation. Therefore, the adjustment range of the blown air temperature and blown air humidity by the air conditioner 100 can be expanded.

Embodiment 6.
Unless otherwise specified, the air conditioner 100 according to the sixth embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the fifth embodiment.

With reference to Figure 15, the configuration of the air conditioner 100 pertaining to embodiment 6 will be described. Figure 15 is a refrigerant circuit diagram of the air conditioner 100 pertaining to embodiment 6. The air conditioner 100 pertaining to embodiment 6 differs from the air conditioner 100 pertaining to embodiment 5 in the second refrigerant shut-off mechanism 16. The second refrigerant shut-off mechanism 16 is a check valve.

Referring to Figures 15 and 16, the operation of the air conditioner 100 according to embodiment 6 is basically the same as that according to embodiment 5.

Next, the effects of the air conditioner 100 according to the sixth embodiment will be described.
In the air conditioner 100 according to the sixth embodiment, the second refrigerant shut-off mechanism 16 is a check valve. Because the refrigerant flows in the same direction inside the outdoor heat exchanger 13 in both cooling-dominated operation and heating-dominated operation, a check valve can be used as the second refrigerant shut-off mechanism 16. Because check valves are less expensive and smaller than solenoid valves, refrigerant shut-off can be achieved at less cost and in a smaller space.

Embodiment 7.
Unless otherwise specified, the air conditioner 100 according to the seventh embodiment has the same configuration, operation, and effects as the air conditioner 100 according to the first embodiment.

With reference to Figure 17, the configuration of the reheater 21 and cooler 22 relating to embodiment 7 will be described. Figure 17 is an oblique view of the reheater 21 and cooler 22 relating to embodiment 7.

The reheater 21 has a smaller internal volume than the cooler 22. The reheater 21 has a first heat transfer tube T1. The cooler 22 has a second heat transfer tube T2. For example, the inner diameter of the first heat transfer tube T1 may be equal to the inner diameter of the second heat transfer tube T2, and the length of the first heat transfer tube T1 may be shorter than the length of the second heat transfer tube T2.

Furthermore, the reheater 21 has a plurality of first fins F1. The cooler 22 has a plurality of second fins F2. The plurality of first fins F1 have a total surface area that is smaller than that of the plurality of second fins F2. For example, the length of the first fins F1 may be shorter than the length of the second fins F2, and the number of first fins F1 may be fewer than the number of second fins F2.

Next, the effects of the air conditioner 100 according to the seventh embodiment will be described.
In the air conditioner 100 according to the seventh embodiment, the reheater 21 has an internal volume smaller than that of the cooler 22. Because the air cooled once in the cooler 22 is reheated in the reheater 21, the temperature difference between the refrigerant and the air in the reheater 21 is larger than the temperature difference between the refrigerant and the air in the cooler 22. For this reason, even if the reheater 21 is designed to be smaller and have a smaller internal volume than the cooler 22, the reheater 21 can still exhibit the heat dissipation capacity required for a preset target blown air temperature.

In addition, by designing the internal volume of the reheater 21 to be small, the amount of change in the amount of liquid refrigerant stored in the reheater 21 due to adjustment of the heat exchange amount in the reheater 21 can be reduced. This makes it possible to suppress excessive increases in the compressor discharge refrigerant temperature and compressor discharge refrigerant pressure. Furthermore, if a liquid receiver 24 is provided, its adjustment capacity can be reduced, allowing the liquid receiver 24 to be made smaller.

In the air conditioner 100 according to embodiment 7, the plurality of first fins F1 have a total surface area that is smaller than that of the plurality of second fins F2. When downsizing the reheater 21, the total surface area of the first fins F1 that come into contact with the air of the reheater 21 can be designed to be smaller than the total surface area of the second fins F2 that come into contact with the air of the cooler 22, thereby enabling the reheater 21 and air conditioner 100 to be constructed inexpensively and compactly.

Furthermore, when a reheater 21 and a cooler 22 are placed inside the air duct 31, by designing the reheater 21 to be small and the cooler 22 to be large, a configuration that delivers optimal performance within the design dimensional constraints of the air conditioner 100 can be realized.

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present disclosure is indicated by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 First pipe, 2 Second pipe, 3 Third pipe, 4 Fourth pipe, 5 Fifth pipe, 6 Sixth pipe, 10 Outdoor unit, 11 Compressor, 12 Six-way valve, 13 Outdoor heat exchanger, 13a First heat exchange section, 13b Second heat exchange section, 14 Outdoor blower, 15 First refrigerant shut-off mechanism, 16 Second refrigerant shut-off mechanism, 17 Bypass circuit, 17a Bypass pipe, 17b Flow rate adjustment mechanism, 20 Indoor unit, 21 Reheater, 22 Cooler, 23 First expansion valve, 24 Receiver, 25 Second expansion valve, 31 Air duct, 32 Blower, 100 Air conditioner, F1 First fin, F2 Second fin, T1 First heat transfer tube, T2 Second heat transfer tube, RC Refrigerant circuit.

Claims (12)

a refrigerant circuit configured to circulate a refrigerant, the refrigerant circuit having a compressor, a six-way valve, an outdoor heat exchanger, a reheater, a first expansion valve, and a cooler;
a blower configured to blow air to the reheater and the cooler,
The six-way valve is configured to be switchable between a first switching state and a second switching state,
The six-way valve is
In the first switching state, the refrigerant circuit is configured to be switched so that the refrigerant flows through the compressor, the six-way valve, the outdoor heat exchanger, the six-way valve, the reheater, the first expansion valve, the six-way valve, and the cooler in this order; and in the second switching state, the refrigerant circuit is configured to be switched so that the refrigerant flows through the compressor, the six-way valve, the reheater, the first expansion valve, the six-way valve, the outdoor heat exchanger, the six-way valve, and the cooler in this order.
The reheater and the cooler are configured so that, in either the first switching state or the second switching state, the air blown by the blower passes through the cooler before passing through the reheater. the refrigerant circuit includes a first pipe connecting the compressor and the six-way valve, a second pipe connecting the six-way valve and the outdoor heat exchanger, a third pipe connecting the outdoor heat exchanger and the six-way valve, a fourth pipe connecting the six-way valve and the reheater, a fifth pipe connecting the reheater and the six-way valve via the first expansion valve, and a sixth pipe connecting the six-way valve and the cooler;
In the first switching state, the refrigerant circuit is configured so that the refrigerant flows in the order of the compressor, the first pipe, the six-way valve, the second pipe, the outdoor heat exchanger, the third pipe, the six-way valve, the fourth pipe, the reheater, the fifth pipe, the first expansion valve, the fifth pipe, the six-way valve, the sixth pipe, and the cooler,
2. The air conditioner of claim 1, wherein in the second switching state, the refrigerant circuit is configured so that the refrigerant flows in the following order: the compressor, the first pipe, the six-way valve, the fourth pipe, the reheater, the fifth pipe, the first expansion valve, the fifth pipe, the six-way valve, the third pipe, the outdoor heat exchanger, the second pipe, the six-way valve, the sixth pipe, and the cooler. the refrigerant circuit includes a first pipe connecting the compressor and the six-way valve, a second pipe connecting the six-way valve and the outdoor heat exchanger, a third pipe connecting the outdoor heat exchanger and the six-way valve, a fourth pipe connecting the six-way valve and the reheater, a fifth pipe connecting the reheater and the six-way valve via the first expansion valve, and a sixth pipe connecting the six-way valve and the cooler;
In the first switching state, the refrigerant circuit is configured so that the refrigerant flows in the order of the compressor, the first pipe, the six-way valve, the second pipe, the outdoor heat exchanger, the third pipe, the six-way valve, the fourth pipe, the reheater, the fifth pipe, the first expansion valve, the fifth pipe, the six-way valve, the sixth pipe, and the cooler,
2. The air conditioner of claim 1, wherein in the second switching state, the refrigerant circuit is configured so that the refrigerant flows in the following order: the compressor, the first pipe, the six-way valve, the fourth pipe, the reheater, the fifth pipe, the first expansion valve, the fifth pipe, the six-way valve, the second pipe, the outdoor heat exchanger, the third pipe, the six-way valve, the sixth pipe, and the cooler. The air conditioner according to claim 1 , wherein the refrigerant is a mixed refrigerant. The refrigerant circuit includes a receiver,
The air conditioner according to claim 1 , wherein the receiver is disposed in the refrigerant circuit between the reheater and the first expansion valve. the refrigerant circuit has a second expansion valve,
The air conditioner according to claim 5, wherein the second expansion valve is disposed in the refrigerant circuit between the reheater and the receiver. the reheater has a refrigerant inlet and a refrigerant outlet;
The air conditioner according to claim 1 , wherein the refrigerant inlet is located higher in the direction of gravity than the refrigerant outlet. the refrigerant circuit has a first refrigerant shut-off mechanism and a second refrigerant shut-off mechanism,
the outdoor heat exchanger has a first heat exchange section and a second heat exchange section,
the first heat exchange unit and the second heat exchange unit are arranged in parallel with each other in the refrigerant circuit,
The first heat exchange unit has a larger internal volume than the second heat exchange unit,
the first refrigerant shut-off mechanism is connected to an inlet of the first heat exchanger;
The air conditioner according to claim 1 , wherein the second refrigerant shut-off mechanism is connected to an outlet of the first heat exchanger. The refrigerant circuit has a bypass circuit,
The air conditioner according to claim 8 , wherein the bypass circuit is arranged in parallel with the outdoor heat exchanger in the refrigerant circuit. The air conditioner of claim 8, wherein the second refrigerant shut-off mechanism is a check valve. The air conditioner according to claim 1 , wherein the reheater has an internal volume smaller than that of the cooler. the reheater has a plurality of first fins;
the cooler has a plurality of second fins;
The air conditioner according to claim 1 , wherein the first fins have a total surface area smaller than that of the second fins.