WO2023084658A1

WO2023084658A1 - Air conditioner

Info

Publication number: WO2023084658A1
Application number: PCT/JP2021/041422
Authority: WO
Inventors: 千歳田中
Original assignee: 三菱電機株式会社
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2023-05-19
Also published as: CN118176395A

Abstract

An air conditioner (100) comprises a refrigerant circuit (RC) and a blower (32). A refrigerant flow path switching mechanism (RF) is configured so as to switch the refrigerant circuit (RC) so that refrigerant flows in the order of a reheater (21), a second expansion valve (23), and a cooler (22) in a first switching state. The refrigerant flow path switching mechanism (RF) is configured so as to switch the refrigerant circuit (RC) so that the refrigerant flows in the order of the reheater (21), the second expansion valve (23), and the cooler (22) in a second switching state. The reheater (21) and the cooler (22) are configured so that in both the first switching state and the second switching state, air blown by the blower (32) passes through the cooler (22) and then through the reheater (21).

Description

air conditioner

The present disclosure relates to air conditioners.

An outdoor unit provided with an outdoor heat exchanger functioning as a condenser, an indoor unit provided with a first indoor heat exchanger functioning as a cooler and a second indoor heat exchanger functioning as a reheater, and an outdoor unit An air conditioner is known that has a heat exchanger, a first indoor heat exchanger, and a compressor that circulates a refrigerant through the second indoor heat exchanger. In this air conditioner, the air cooled and dehumidified by the first indoor heat exchanger is heated by the second indoor heat exchanger, so that the temperature and humidity of the air blown out from the indoor unit into the air-conditioned space are are individually adjusted. Such an air conditioner is described, for example, in Japanese Patent Laying-Open No. 2002-89998 (Patent Document 1).

JP-A-2002-89998

However, in the air conditioner described in the above publication, only one four-way valve is used as the refrigerant channel switching mechanism. Therefore, when the cooling-main operation and the heating-main operation are performed corresponding to the two switching states of the four-way valve, the direction of the refrigerant flowing through the indoor unit is reversed between the cooling-main operation and the heating-main operation. Therefore, the indoor heat exchanger functioning as a cooler and the indoor heat exchanger functioning as a reheater are switched between the cooling main operation and the heating main operation. As a result, in either the cooling main operation or the heating main operation, the air heated by the reheater is cooled by the cooler, so sufficient dehumidification cannot be performed.

The present disclosure has been made in view of the above problems, and an object thereof is to provide an air conditioner in which the direction of the refrigerant flowing through the reheater and the cooler can be the same in both cooling-dominant operation and heating-dominant operation. to provide.

The air conditioner of the present disclosure includes a refrigerant circuit and a blower. The refrigerant circuit has a compressor, a refrigerant channel switching mechanism, an outdoor heat exchanger, a first expansion valve, a reheater, a second expansion valve, and a cooler, and is configured to circulate the refrigerant. The blower is configured to blow air to the reheater and the cooler. The refrigerant channel switching mechanism is configured to be switchable between a first switching state and a second switching state. In the first switching state, the refrigerant flow switching mechanism divides the refrigerant circuit into the compressor, the refrigerant flow switching mechanism, the outdoor heat exchanger, the first expansion valve, the refrigerant flow switching mechanism, the reheater, and the second expansion valve. , the cooler, and the refrigerant flow switching mechanism are switched so that the refrigerant flows in this order. In the second switching state, the refrigerant flow switching mechanism connects the refrigerant circuit to the compressor, the refrigerant flow switching mechanism, the reheater, the second expansion valve, the cooler, the refrigerant flow switching mechanism, the first expansion valve, the outdoor It is configured to switch so that the refrigerant flows in the order of the heat exchanger and the refrigerant flow switching mechanism. The reheater and cooler are configured such that in both the first switching state and the second switching state, air blown by the blower passes through the cooler and then through the reheater.

According to the air conditioner of the present disclosure, the refrigerant flow switching mechanism is configured to switch the refrigerant circuit so that the refrigerant flows in order of the reheater and the cooler in both the first switching state and the second switching state. It is Therefore, the direction of the refrigerant flowing through the reheater and the cooler can be the same in both the cooling-dominant operation and the heating-dominant operation.

FIG. 3 is a refrigerant circuit diagram of cooling-main operation of the air conditioner according to Embodiment 1; FIG. 2 is a refrigerant circuit diagram of a heating-dominant operation of the air conditioner according to Embodiment 1; 4 is a schematic diagram of a first switching state of the rotary hexagonal valve of the air conditioner according to Embodiment 1. FIG. 4 is a schematic diagram of a second switching state of the rotary hexagonal valve of the air conditioner according to Embodiment 1. FIG. 4 is a schematic diagram of a first switching state of the slide-type hexagonal valve of the air conditioner according to Embodiment 1. FIG. 4 is a schematic diagram of a second switching state of the slide-type hexagonal valve of the air conditioner according to Embodiment 1. FIG. FIG. 10 is a refrigerant circuit diagram of cooling-dominant operation of the air conditioner according to Embodiment 2; FIG. 7 is a refrigerant circuit diagram of a heating-dominant operation of the air conditioner according to Embodiment 2; FIG. 11 is a refrigerant circuit diagram of cooling-dominant operation of the air conditioner according to Embodiment 3; FIG. 11 is a refrigerant circuit diagram of a heating-dominant operation of an air conditioner according to Embodiment 3; FIG. 11 is a perspective view of a reheater of an air conditioner according to Embodiment 3; FIG. 11 is a perspective view of a cooler of an air conditioner according to Embodiment 3; FIG. 11 is a perspective view of a reheater of an air conditioner according to Embodiment 4; FIG. 11 is a perspective view of a cooler of an air conditioner according to Embodiment 4; FIG. 11 is a cross-sectional view of a fin of a reheater of an air conditioner according to Embodiment 4;

An embodiment will be described below with reference to the drawings. In the following description, the same reference numerals are given to the same or corresponding parts, and the description thereof will not be repeated.

Embodiment 1.
A configuration of an air conditioner 100 according to Embodiment 1 will be described with reference to FIG.

<Device configuration>
FIG. 1 is a refrigerant circuit diagram of an air conditioner 100 according to Embodiment 1. FIG. As shown in FIG. 1, the air conditioner 100 includes a refrigerant circuit RC, a sensor 15, an air passage 31, a blower 32, and a controller CD. The refrigerant circuit RC includes a high-pressure pipe 1, a low-pressure pipe 2, a discharge pipe 3, a suction pipe 4, a gas pipe 5, a liquid pipe 6, a compressor 11, a refrigerant flow switching mechanism RF, an outdoor heat exchanger 13, and a first expansion valve. 14 , a reheater 21 , a cooler 22 and a second expansion valve 23 .

In the refrigerant circuit RC, a compressor 11, a refrigerant flow switching mechanism RF, an outdoor heat exchanger 13, a first expansion A valve 14, a reheater 21, a cooler 22 and a second expansion valve 23 are connected.

The high-pressure pipe 1 is connected to the refrigerant flow switching mechanism RF and the reheater 21 . The low-pressure pipe 2 is connected to the refrigerant flow switching mechanism RF and the cooler 22 . The discharge pipe 3 is connected to the discharge side of the compressor 11 and the refrigerant flow switching mechanism RF. The suction pipe 4 is connected to the suction side of the compressor 11 and the refrigerant flow switching mechanism RF. The gas pipe 5 is connected to the refrigerant flow switching mechanism RF and the outdoor heat exchanger 13 . The liquid pipe 6 connects the outdoor heat exchanger 13 and the refrigerant flow switching mechanism RF via the first expansion valve 14 .

The refrigerant circuit RC is configured to circulate the refrigerant. The refrigerant is a mixed refrigerant. A mixed refrigerant is a mixture of two or more refrigerants. Note that the refrigerant may be a single refrigerant.

The air conditioner 100 includes an outdoor unit 10 and an indoor unit 20. An outdoor unit 10 and an indoor unit 20 are connected by a high pressure pipe 1 and a low pressure pipe 2 . The outdoor unit 10 has a compressor 11, a refrigerant flow switching mechanism RF, an outdoor heat exchanger 13, a first expansion valve 14, a sensor 15, and a control device CD. The compressor 11 , the refrigerant flow switching mechanism RF, the outdoor heat exchanger 13 , the first expansion valve 14 , the sensor 15 and the controller CD are housed in the outdoor unit 10 . The indoor unit 20 has a reheater 21 , a cooler 22 , a second expansion valve 23 , an air passage 31 and a blower 32 . The reheater 21 , the cooler 22 , the second expansion valve 23 and the blower 32 are housed in the indoor unit 20 . An air passage 31 is provided in the indoor unit 20 .

The compressor 11 is configured to compress refrigerant. The compressor 11 is configured to compress and discharge the sucked refrigerant. Compressor 11 is configured, for example, to have a variable capacity. Compressor 11 is configured, for example, to change its capacity by adjusting the rotational speed of compressor 11 based on an instruction from control device CD.

The refrigerant channel switching mechanism RF is configured to be switchable between a first switching state and a second switching state. The coolant flow path switching mechanism RF is configured, for example, to be switched between a first switching state and a second switching state based on an instruction from the control device CD. In the first switching state, the refrigerant flow switching mechanism RF connects the refrigerant circuit RC to the compressor 11, the refrigerant flow switching mechanism RF, the outdoor heat exchanger 13, the first expansion valve 14, the refrigerant flow switching mechanism RF, and the refrigerant circuit RC. The refrigerant is switched to flow in the order of the heater 21, the second expansion valve 23, the cooler 22, and the refrigerant flow switching mechanism RF. The refrigerant flow switching mechanism RF is in the first switching state in the cooling-dominant operation.

In the second switching state, the refrigerant flow switching mechanism RF connects the refrigerant circuit RC to the compressor 11, the refrigerant flow switching mechanism RF, the reheater 21, the second expansion valve 23, the cooler 22, and the refrigerant flow switching mechanism. RF, the first expansion valve 14, the outdoor heat exchanger 13, and the refrigerant flow switching mechanism RF are configured to switch so that the refrigerant flows in this order. The refrigerant flow switching mechanism RF is in the second switching state in the heating main operation.

In Embodiment 1, the refrigerant flow switching mechanism RF is the hexagonal valve 12 . Each of the six connection ports (first connection port P1 to sixth connection port P6) of the hexagonal valve 12 is connected to the high pressure pipe 1, the low pressure pipe 2, the discharge pipe 3, the suction pipe 4, the gas pipe 5, and the liquid pipe 6, respectively. It is connected. The first connection port P1 is connected to the discharge pipe 3 . The second connection port P2 is connected to the gas pipe 5 . The third connection port P3 is connected to the suction pipe 4 . The fourth connection port P4 is connected to the low pressure pipe 2 . The fifth connection port P5 is connected to the liquid pipe 6 . The sixth connection port P6 is connected to the high pressure pipe 1 .

In the first switching state of the hexagonal valve 12, the compressor 11, the discharge pipe 3, the hexagonal valve 12, the gas pipe 5, the outdoor heat exchanger 13, the liquid pipe 6, the first expansion valve 14, the hexagonal valve 12, the high pressure pipe 1, A refrigerant circuit RC is configured to reach the compressor 11 again via the reheater 21 , the second expansion valve 23 , the cooler 22 , the low-pressure pipe 2 , the hexagonal valve 12 , and the suction pipe 4 . In the first switching state of the hexagonal valve 12, the first connection port P1 is connected to the second connection port P2, the third connection port P3 is connected to the fourth connection port, and the fifth connection port is connected to the sixth connection port. The port is connected.

In the second switching state of the hexagonal valve 12, the compressor 11, the discharge pipe 3, the hexagonal valve 12, the high pressure pipe 1, the reheater 21, the second expansion valve 23, the cooler 22, the low pressure pipe 2, the hexagonal valve 12, the 1 expansion valve 14 , liquid pipe 6 , outdoor heat exchanger 13 , gas pipe 5 , hexagonal valve 12 , suction pipe 4 , and again to compressor 11 , refrigerant circuit RC is configured. In the second switching state of the hexagonal valve 12, the first connection port P1 is connected to the sixth connection port P6, the second connection port P2 is connected to the third connection port P3, and the fourth connection port P4 is connected to The fifth connection port P5 is connected.

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 in the cooling main operation and the cooling operation. The outdoor heat exchanger 13 is configured to function as an evaporator that evaporates the refrigerant in the heating main operation and the heating operation. The outdoor heat exchanger 13 is, for example, a fin-and-tube heat exchanger having a plurality of fins and heat transfer tubes passing through the plurality of fins.

The first expansion valve 14 is configured to reduce the pressure by expanding the refrigerant condensed in the condenser. The first expansion valve 14 is in a fully open state and does not function as a decompression device in the cooling-dominant operation and the heating-dominant operation. The first expansion valve 14 is configured to reduce the pressure of the refrigerant condensed by the outdoor heat exchanger 13 during cooling operation. The first expansion valve 14 is configured to reduce the pressure of the refrigerant condensed by the reheater 21 and the cooler 22 during heating operation.

The first expansion valve 14 is, for example, an electromagnetic expansion valve. The first expansion valve 14 is configured such that the degree of opening of the first expansion valve 14 is adjusted based on instructions from the control device CD, for example, so that the amount of pressure reduction changes.

The sensor 15 is installed between the first expansion valve 14 and the refrigerant flow switching mechanism RF in the refrigerant circuit RC. The sensor 15 is installed on a pipe connecting the first expansion valve 14 and the refrigerant flow switching mechanism RF. Sensor 15 is configured to be able to measure the pressure or temperature of the refrigerant in this pipe. The sensor 15 is configured to be able to measure the pressure or temperature of the refrigerant in the refrigerant circuit RC. The sensor 15 may be a refrigerant pressure sensor that can measure the pressure of the refrigerant, or a refrigerant temperature sensor that can measure the temperature of the refrigerant.

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, the refrigerant flow switching mechanism RF, the first expansion valve 14, the sensor 15, the second expansion valve 23, the blower 32, etc., and controls these operations. is configured to

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 the cooling-dominant operation, the heating-dominant operation, and the heating operation. The reheater 21 is configured to function as an evaporator that evaporates the refrigerant during cooling operation. The reheater 21 is, for example, a fin-and-tube heat exchanger having a plurality of fins and heat transfer tubes passing through the plurality of 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-dominant operation, heating-dominant operation, and cooling operation. The cooler 22 is configured to function as a condenser that condenses the refrigerant during heating operation. Cooler 22 is, for example, a fin-and-tube heat exchanger having a plurality of fins and heat transfer tubes passing through the plurality of fins.

The second expansion valve 23 is configured to reduce the pressure by expanding the refrigerant condensed by the condenser. The second expansion valve 23 is configured to reduce the pressure of the refrigerant condensed by the reheater 21 in the cooling main operation and the heating main operation. The second expansion valve 23 is fully open during cooling operation and heating operation, and does not function as a decompression device. The second expansion valve 23 is, for example, an electromagnetic expansion valve. The second expansion valve 23 is configured such that the degree of opening of the second expansion valve 23 is adjusted based on instructions from the control device CD, for example, so that the amount of pressure reduction changes.

The air passage 31 is provided in the housing of the indoor unit 20. A reheater 21 and a cooler 22 are arranged in the air passage 31 . Air blower 32 is configured to blow air to reheater 21 and cooler 22 . The reheater 21 and the cooler 22 are arranged side by side in the direction of air flow blown by the blower 32 . The reheater 21 is arranged on the leeward side of the cooler 22 in the flow of air blown by the blower 32 . The cooler 22 is arranged upstream of the reheater 21 in the air passage 31 .

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 such that the air blown by the blower 32 passes through the cooler 22 and then the reheater 21 in both the first switching state and the second switching state. ing. During operation of the blower 32, regardless of the first switching state and the second switching state of the hexagonal valve 12, the reheater 21 and the cooling device are operated so that the air passes through the reheater 21 after passing through the cooler 22. The vessel 22 is constructed.

The reheater 21 and the cooler 22 may be configured so that the refrigerant flows countercurrent to the air flow. Both the reheater 21 and the cooler 22 have a heat transfer tube flow path configuration in which air and refrigerant flow countercurrently. Each of the reheater 21 and the cooler 22 has a windward heat transfer tube and a leeward heat transfer tube. The heat transfer tube on the windward side is connected to the heat transfer tube on the leeward side. In the cooling-dominant operation and the heating-dominant operation, the refrigerant is configured to flow from the heat transfer tube on the leeward side to the heat transfer tube on the windward side. In both the cooling-dominant operation and the heating-dominant operation, the refrigerant flowing inside the heat transfer tubes of the reheater 21 and the cooler 22 and the air flowing outside the heat transfer tubes flow in opposite directions.

Next, operation of the air conditioner 100 according to Embodiment 1 will be described.
<Cooling main operation>
First, the cooling-dominant operation of the air conditioner 100 according to Embodiment 1 will be described with reference to FIG. In the cooling-dominant operation, the cooling amount of the air in the cooler 22 is larger than the heating amount of the air in the reheater 21, and the outdoor heat exchanger 13 functions as a condenser, so that the surplus heat radiation amount of the heat pump is reduced. This is an operation in which heat is released to the outside air. In the cooling-dominant operation, the air after passing through the reheater 21 has a lower temperature and a lower moisture content than the air before passing through the cooler 22 .

In the cooling-dominant operation, the hexagonal valve 12 is switched to the first switching state as indicated by the solid line in FIG. The vapor refrigerant compressed to high temperature and high pressure by the compressor 11 flows out to the discharge pipe 3 , passes through the hexagonal valve 12 , and flows into the outdoor heat exchanger 13 via the gas pipe 5 . The outdoor heat exchanger 13 functions as a condenser. The high-temperature and high-pressure vapor refrigerant radiates heat to outdoor air introduced into the outdoor heat exchanger 13 by an outdoor blower (not shown). As a result, the high-temperature and high-pressure vapor refrigerant is condensed into a high-temperature and high-pressure gas-liquid two-phase refrigerant.

The high-temperature, high-pressure gas-liquid two-phase refrigerant flows out to the liquid pipe 6, passes through the first expansion valve 14, the hexagonal valve 12, and flows into the reheater 21 via the high-pressure pipe 1. The reheater 21 functions as a condenser. The high-temperature and high-pressure gas-liquid two-phase refrigerant radiates heat to the air introduced into the reheater 21 by the blower 32 . As a result, the high-temperature and high-pressure gas-liquid two-phase refrigerant is condensed into a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows into the second expansion valve 23 .

This high-pressure liquid refrigerant is expanded by the second expansion valve 23 and decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. This low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the cooler 22 . 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 to become a low-pressure vapor refrigerant. After that, the low-pressure vapor refrigerant flows into the hexagonal valve 12 via the low-pressure pipe 2 and is sucked into the compressor 11 via the suction pipe 4 . In the cooling-dominant operation, the refrigerant circulates through the refrigerant circuit RC in the same process thereafter.

The reheater 21 and the cooler 22 share the air passage 31 and the blower 32. The air guided through the air passage 31 by the blower 32 is first cooled and dehumidified by passing through the cooler 22 . This lowers the temperature of the air and reduces the moisture content of the air. The air that has finished passing through the cooler 22 is heated by being led to the air passage 31 and passing through the reheater 21 . This increases the temperature of the air. Incidentally, since humidification is generally not performed in the reheater 21 , the moisture content of the air does not change before and after passing through the reheater 21 . The air that has finished passing through the reheater 21 is guided to the air passage 31 and blown out to the air conditioning target space.

After the air is cooled and dehumidified in the cooler 22, it is heated in the reheater 21 as necessary, so the amount of dehumidification of the air and the temperature of the air can be individually adjusted. Therefore, air having a temperature and humidity set by the user can be supplied to the space to be air-conditioned.

<Heating main operation>
Next, the heating main operation of the air conditioner 100 according to Embodiment 1 will be described with reference to FIG. In the heating-dominant operation, the amount of air heating in the reheater 21 is greater than the amount of air cooling in the cooler 22, and the outdoor heat exchanger 13 functions as an evaporator, so that the surplus cold heat amount of the heat pump is reduced. This is an operation in which heat is exhausted to the outside air. In the heating-dominant operation, the air after passing through the reheater 21 has a higher temperature and a lower moisture content than the air before passing through the cooler 22 .

　In the heating main operation, the hexagonal valve 12 is switched to the second switching state as indicated by the solid line in FIG. The vapor refrigerant compressed to high temperature and high pressure by the compressor 11 flows out to the discharge pipe 3 , passes through the hexagonal valve 12 , and flows into the reheater 21 via the high pressure pipe 1 . The reheater 21 functions as a condenser. The high-temperature and high-pressure vapor refrigerant radiates heat to the air introduced into the reheater 21 by the blower 32 . As a result, the high-temperature and high-pressure vapor refrigerant is condensed into a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows into the second expansion valve 23 .

This high-pressure liquid refrigerant is expanded by the second expansion valve 23 and decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. This low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the cooler 22 . Cooler 22 functions as an evaporator. By absorbing heat from the air introduced into the cooler 22 by the blower 32, part of the low-temperature, low-pressure gas-liquid two-phase refrigerant evaporates. After that, the low-temperature and low-pressure gas-liquid two-phase refrigerant flows through the low-pressure pipe 2 into the hexagonal valve 12, flows out into the liquid pipe 6, and flows through the first expansion valve 14 into the outdoor heat exchanger 13. .

The outdoor heat exchanger 13 functions as an evaporator. By absorbing heat from outdoor air introduced into the outdoor heat exchanger 13 by an outdoor blower (not shown), the low-temperature, low-pressure gas-liquid two-phase refrigerant evaporates to become a low-pressure vapor refrigerant. This low-pressure vapor refrigerant flows into the hexagonal valve 12 via the gas pipe 5 and is sucked into the compressor 11 via the suction pipe 4 . In the heating-dominant operation, the refrigerant thereafter circulates in the refrigerant circuit RC in the same process.

The air guided through the air passage 31 by the blower 32 is cooled and dehumidified by the cooler 22, then heated by the reheater 21 and blown out to the air conditioning target space, as in the cooling main operation. Therefore, the amount of dehumidification of the air and the temperature of the air can be individually adjusted. Therefore, air having a temperature and humidity set by the user can be supplied to the space to be air-conditioned.

<Cooling operation>
The cooling operation will be described with reference to FIG. 1 again. In cooling operation, the first expansion valve 14 expands the refrigerant. That is, in cooling operation, the first expansion valve 14 functions as an expansion valve. On the other hand, in cooling operation, the second expansion valve 23 is fully open and does not function as an expansion valve.

In the cooling operation, the refrigerant circuit RC includes the compressor 11, the refrigerant flow switching mechanism RF, the outdoor heat exchanger 13, the first expansion valve 14, the refrigerant flow switching mechanism RF, the reheater 21, the second expansion valve 23, The coolant circulates in the order of the cooler 22 and the coolant flow switching mechanism RF.

<Heating operation>
The heating operation will be described with reference to FIG. 2 again. In heating operation, the first expansion valve 14 expands the refrigerant. That is, in heating operation, the first expansion valve 14 functions as an expansion valve. On the other hand, in heating operation, the second expansion valve 23 is fully open and does not function as an expansion valve.

In the heating operation, the refrigerant circuit RC is composed of the compressor 11, the refrigerant flow switching mechanism RF, the reheater 21, the second expansion valve 23, the cooler 22, the refrigerant flow switching mechanism RF, the first expansion valve 14, the outdoor heat The refrigerant circulates in the order of the exchanger 13 and the refrigerant flow switching mechanism RF.

Next, functions and effects of the air conditioner 100 according to Embodiment 1 will be described.
According to the air conditioner according to Embodiment 1, the refrigerant flow switching mechanism RF causes the refrigerant to flow through the refrigerant circuit RC in the order of the reheater 21 and the cooler 22 in both the first switching state and the second switching state. It is configured so that it can be switched as follows. The refrigerant flow switching mechanism RF is in the first switching state during the cooling main operation, and is in the second switching state during the heating main operation. Therefore, the direction of the refrigerant flowing through the reheater 21 and the cooler 22 can be the same in both the cooling-dominant operation and the heating-dominant operation.

Further, the reheater 21 and the cooler 22 are arranged so that the air blown by the blower 32 passes through the cooler 22 and then the reheater 21 in both the first switching state and the second switching state. It is configured. Therefore, in both the cooling-dominant operation and the heating-dominant operation, the air can be cooled and dehumidified and then reheated. Therefore, sufficient dehumidification can be performed in both the cooling main operation and the heating main operation.

In particular, since sufficient dehumidification can be performed in heating-dominant operation, heating-dominant operation can be used for drying and dehumidifying the space to be air-conditioned. Therefore, the air conditioner 100 according to Embodiment 1 can also be used for drying foods and materials.

In the air conditioner 100 according to Embodiment 1, the refrigerant channel switching mechanism RF is the hexagonal valve 12 . Therefore, in both the cooling-dominant operation and the heating-dominant operation, the flow directions of the refrigerant flowing through the reheater 21 and the cooler 22 can be the same. Therefore, in both the cooling main operation and the heating main operation, the air cooled and dehumidified by the cooler 22 can be heated by the reheater 21 . Therefore, air having a temperature and humidity set by the user can be supplied to the space to be air-conditioned.

When noise and vibration in the indoor space are not desired, the configuration of the air conditioner 100 called a separate type in which the compressor 11 is installed in the outdoor unit 10 is used. is preferable to the configuration of the air conditioner 100 called a remote type. The remote type generally has a refrigerant circuit configuration in which one end of the reheater 21 is connected to the discharge pipe 3 without passing through the refrigerant flow switching mechanism RF, and the other end of the reheater 21 is connected to the liquid pipe 6. be. In this refrigerant circuit configuration, if a separate type configuration in which the compressor 11 is installed in the outdoor unit 10 is adopted, the outdoor unit 10 and the indoor unit 20 are connected to three lines of the discharge pipe 3, the liquid pipe 6, and the low pressure pipe 2. must be connected with In the configuration of air conditioner 100 according to Embodiment 1, outdoor unit 10 and indoor unit 20 are connected by high-pressure pipe 1 and low-pressure pipe 2 . Therefore, since the outdoor unit 10 and the indoor unit 20 can be connected by the two high-pressure pipes 1 and the low-pressure pipes 2, the labor for construction can be reduced.

According to the air conditioner 100 according to Embodiment 1, the sensor 15 is configured to be able to measure the pressure or temperature of the refrigerant in the refrigerant circuit RC. Therefore, in the cooling-dominant operation, the first expansion valve 14 can adjust the heating amount of the air based on the result of the sensor 15 measuring the pressure or temperature of the refrigerant in the reheater 21 . Further, the first expansion valve 14 can adjust the cooling amount of the air based on the result of the sensor 15 measuring the pressure or temperature of the refrigerant in the cooler 22 in the heating-dominant operation. Therefore, it is possible to finely adjust the refrigerant condensation temperature in the reheater 21 in the cooling-dominant operation, and the refrigerant evaporation temperature in the cooler 22 in the heating-dominant operation. Thereby, the temperature and humidity of the air blown out from the air conditioner 100 can be stably controlled.

Specifically, for example, the refrigerant pressure value in the reheater 21 in the cooling main operation or the refrigerant pressure in the cooler 22 in the heating main operation corresponding to the temperature and humidity of the blown air of the air conditioner 100 set by the user When the value is known in advance, the opening command for the first expansion valve 14 is adjusted so that the measured value of the sensor 15 approaches the refrigerant pressure value.

According to the air conditioner 100 according to Embodiment 1, the refrigerant is a mixed refrigerant. A mixed refrigerant, which is a mixture of two or more kinds of refrigerants, is generally non-azeotropic, so the temperature during the gas-liquid phase change is not constant. Therefore, a temperature gradient is generated in the heat exchanger according to the phase change of the mixed refrigerant. Therefore, optimum design of the heat exchanger is required. In the air conditioner 100 according to Embodiment 1, the reheater 21 and the cooler 22 can be specially designed, so even if a mixed refrigerant is used, the high performance air conditioner 100 can be realized.

According to the air conditioner 100 according to Embodiment 1, the reheater 21 and the cooler 22 are configured so that the refrigerant flows countercurrent to the air flow. Therefore, the temperature gradient of the mixed refrigerant in the heat exchanger can be utilized to reduce the heat exchange temperature difference between the air and the refrigerant. Therefore, high performance operation of the air conditioner 100 can be realized.

Since the temperature of the non-azeotropic refrigerant rises as the refrigerant evaporates, by making the air and the refrigerant counterflow in the cooler 22 that functions as an evaporator, the temperature rise in the refrigerant flow direction and the air flow The temperature drops in the directions can interact to reduce the heat exchange temperature difference between the air and the refrigerant across the cooler 22 .

In addition, since the temperature of the non-azeotropic refrigerant decreases as the refrigerant condenses, the reheater 21 that functions as a condenser has a structure in which the air and the refrigerant flow in opposite directions, thereby decreasing the temperature in the flow direction of the refrigerant and The temperature rise in the air flow direction can interact to reduce the heat exchange temperature difference between the air and the refrigerant across the reheater 21 .

It should be noted that the position of the blower 32 is not limited to the upstream of the air passage 31 of the cooler 22 as shown in FIGS. The position of the blower 32 may be between the cooler 22 and the reheater 21 in the air passage 31 or may be downstream of the air passage 31 of the reheater 21 .

Also, with reference to FIGS. 3 and 4, the hexagonal valve 12 may have a rotary configuration. FIG. 3 is a schematic diagram of the first switching state of the rotary hexagonal valve 12. As shown in FIG. FIG. 4 is a schematic diagram of the second switching state of the rotary hexagonal valve 12. As shown in FIG. The rotary six-way valve 12 has a valve seat 12a and a valve body 12b rotatable with respect to the valve seat 12a. The flow path is switched between the first switching state and the second switching state by rotating the valve body 12b with respect to the valve seat 12a.

Also, referring to FIGS. 5 and 6, the hexagonal valve 12 may have a slide type configuration. FIG. 5 is a schematic diagram of the first switching state of the slide-type hexagonal valve 12. As shown in FIG. FIG. 6 is a schematic diagram of the second switching state of the slide-type hexagonal valve 12. As shown in FIG. The slide-type hexagonal valve 12 has a valve seat 12a and a valve body 12b configured to be slidable with respect to the valve seat 12a. The flow path is switched between the first switching state and the second switching state by sliding the valve body 12b against the valve seat 12a.

Embodiment 2.
The air conditioner 100 according to Embodiment 2 has the same configuration, operation, and effects as those of the air conditioner 100 according to Embodiment 1 unless otherwise specified.

<Device configuration>
FIG. 7 is a refrigerant circuit diagram of the air conditioner 100 according to Embodiment 2. As shown in FIG. A configuration of the air conditioner 100 according to Embodiment 2 will be described with reference to FIG.

In Embodiment 2, the refrigerant flow switching mechanism RF has the four-way valve 41 and the check valve bridge circuit NC. The four-way valve 41 is connected to the compressor 11, the outdoor heat exchanger 13 and the check valve bridge circuit NC. The check valve bridge circuit NC has a first check valve 42 , a second check valve 43 , a third check valve 44 and a fourth check valve 45 .

Each of the four connection ports (first connection port P1 to fourth connection port P4) of the four-way valve 41 is connected to the high-pressure pipe 1 or the low-pressure pipe 2, the discharge pipe 3, the suction pipe 4, and the gas pipe 5, respectively. . The first connection port P1 is connected to the discharge pipe 3 . The second connection port P2 is connected to the gas pipe 5 . The third connection port P3 is connected to the inlet of the first check valve 42 and the outlet of the fourth check valve 45 . The fourth connection port P4 is connected to the suction pipe 4 .

The outflow port of the first check valve 42 and the outflow port of the third check valve 44 are connected to the high pressure pipe 1 . The inlet of the fourth check valve 45 and the inlet of the second check valve 43 are connected to the low-pressure pipe 2 . The outflow port of the second check valve 43 and the inflow port of the third check valve 44 are connected to the liquid pipe 6 .

In the first switching state of the four-way valve 41, the compressor 11, the discharge pipe 3, the four-way valve 41, the gas pipe 5, the outdoor heat exchanger 13, the liquid pipe 6, the first expansion valve 14, the third check valve 44, the high pressure Refrigerant circuit RC leading to compressor 11 again via pipe 1, reheater 21, second expansion valve 23, cooler 22, low pressure pipe 2, fourth check valve 45, four-way valve 41, suction pipe 4 is configured. In the first switching state of the four-way valve 41, the second connection port P2 is connected to the first connection port P1, and the fourth connection port is connected to the third connection port P3.

In the second switching state of the four-way valve 41, the compressor 11, the discharge pipe 3, the four-way valve 41, the first check valve 42, the high-pressure pipe 1, the reheater 21, the second expansion valve 23, the cooler 22, and the low-pressure pipe. 2. Refrigerant circuit RC leading to compressor 11 again via second check valve 43, first expansion valve 14, liquid pipe 6, outdoor heat exchanger 13, gas pipe 5, four-way valve 41, suction pipe 4 is configured. In the second switching state of the four-way valve 41, the third connection port P3 is connected to the first connection port P1, and the fourth connection port P4 is connected to the second connection port P2.

Next, operation of the air conditioner 100 according to Embodiment 2 will be described.
The operation of the air conditioner 100 according to the second embodiment is basically the same as that of the first embodiment. Referring to FIG. 7, in the cooling main operation of air conditioner 100 according to Embodiment 2, refrigerant is used in compressor 11, discharge pipe 3, four-way valve 41, gas pipe 5, outdoor heat exchanger 13, liquid pipe 6, first expansion valve 14, third check valve 44, high pressure pipe 1, reheater 21, second expansion valve 23, cooler 22, low pressure pipe 2, fourth check valve 45, four-way valve 41, suction It flows through the refrigerant circuit RC to the compressor 11 again via the pipe 4 .

Referring to FIG. 8, in the heating-dominant operation of air conditioner 100 according to Embodiment 2, refrigerant is supplied to compressor 11, discharge pipe 3, four-way valve 41, first check valve 42, high-pressure pipe 1, re Heater 21, second expansion valve 23, cooler 22, low-pressure pipe 2, second check valve 43, first expansion valve 14, liquid pipe 6, outdoor heat exchanger 13, gas pipe 5, four-way valve 41, suction It flows through the refrigerant circuit RC to the compressor 11 again via the pipe 4 .

Referring to FIG. 7 again, in the cooling operation of the air conditioner 100 according to Embodiment 2, the refrigerant flows through the refrigerant circuit RC as in the cooling main operation. Referring to FIG. 8 again, in the heating operation of the air conditioner 100 according to Embodiment 2, the refrigerant flows through the refrigerant circuit RC as in the heating main operation.

Next, effects of the air conditioner 100 according to Embodiment 2 will be described.
In the air conditioner 100 according to Embodiment 2, the refrigerant flow switching mechanism RF has the four-way valve 41 and the check valve bridge circuit NC. Therefore, the direction of the refrigerant flowing through the reheater 21 and the cooler 22 can be the same in both the cooling-dominant operation and the heating-dominant operation. Therefore, in both the cooling main operation and the heating main operation, the air cooled and dehumidified by the cooler 22 can be heated by the reheater 21 . Therefore, air having a temperature and humidity set by the user can be supplied to the space to be air-conditioned.

In addition, since the refrigerant flow switching mechanism RF can be composed of the four-way valve 41 and the check valve bridge circuit NC, the refrigerant flow switching mechanism RF can be composed of inexpensive parts.

Embodiment 3.
The air conditioner 100 according to Embodiment 3 has the same configuration, operation, and effects as those of the air conditioner 100 according to Embodiment 1 unless otherwise specified.

The configuration of the air conditioner 100 according to Embodiment 3 will be described with reference to FIGS. 9 and 10. FIG.

As shown in FIGS. 9 and 10, the reheater 21 has a plurality of first heat transfer paths T1 arranged in parallel. The cooler 22 has a plurality of second heat transfer paths T2 arranged in parallel.

11 and 12, the parallel number of the plurality of second heat transfer paths T2 of the cooler 22 is greater than the number of the plurality of first heat transfer paths T1 of the reheater 21. The number of parallels is the number of branches. In other words, the number of parallels is the number of passes.

Next, functions and effects of the air conditioner 100 according to Embodiment 3 will be described.
The refrigerant in the reheater 21 is in a high temperature and high pressure state and has a high density. Therefore, by reducing the parallel number of the first heat transfer passages T1, the heat transfer coefficient in the heat transfer passages can be increased by increasing the flow velocity of the refrigerant. Therefore, reducing the number of parallel first heat transfer paths T1 contributes to improving the performance of the air conditioner 100 .

The refrigerant in the cooler 22 is in a low temperature, low pressure state and has a low density. Therefore, by increasing the parallel number of the second heat transfer passages T2, it is possible to reduce the pressure loss in the heat transfer passages by reducing the flow velocity of the refrigerant. Therefore, increasing the parallel number of the second heat transfer paths T2 contributes to improving the performance of the air conditioner 100. FIG.

Therefore, according to the air conditioner 100 according to Embodiment 3, the parallel number of the plurality of second heat transfer passages T2 of the cooler 22 is greater than the number of parallelization of the plurality of first heat transfer passages T1 of the reheater 21. Therefore, the high-performance air conditioner 100 can be realized.

Since a dedicated design is possible with the heat exchanger on the upstream side of the air passage as the cooler 22 and the heat exchanger on the downstream side of the air passage as the reheater 21, from the viewpoint of designing the number of parallel branches of the heat transfer tubes in the heat exchanger Optimum design is possible for the effect of improving the performance by improving the heat transfer coefficient of the refrigerant and the effect of improving the performance by reducing the pressure loss of the refrigerant.

Embodiment 4.
The air conditioner 100 according to Embodiment 4 has the same configuration, operation, and effects as those of the air conditioner 100 according to Embodiment 1 unless otherwise specified.

The configurations of the reheater 21 and the cooler 22 of the air conditioner 100 according to Embodiment 4 will be described with reference to FIGS. 13 to 15. FIG.

As shown in FIG. 13, the reheater 21 has first fins F1. The reheater 21 may have a plurality of first fins F1. As shown in FIG. 14, the cooler 22 has second fins. The cooler 22 may have a plurality of second fins F2. The contact angle with water on the surface of the second fins F2 of the cooler 22 is smaller than the contact angle with water on the surface of the first fins F1 of the reheater 21 .

As shown in FIG. 15, the surfaces of the second fins F2 of the cooler 22, on which dew condensation occurs when the air is cooled, are subjected to a hydrophilic treatment in order to suppress dewdrops in the air passage and improve the drainage performance of the fin surfaces. preferably The second fin F2 of the cooler 22 has a body portion Fa and a hydrophilic treatment portion Fb covering the surface of the body portion Fa. On the other hand, since dew condensation water does not occur on the fin surfaces of the reheater 21, costly hydrophilic treatment is unnecessary.

Next, functions and effects of the air conditioner 100 according to Embodiment 4 will be described.
According to the air conditioner 100 according to Embodiment 4, the contact angle with water on the surface of the second fin F2 of the cooler 22 is the contact angle with water on the surface of the first fin F1 of the reheater 21. smaller than the corner. Therefore, it is possible to realize the air conditioner 100 that satisfies both dehumidification performance and cost.

Since the heat exchanger on the upstream side of the air passage is the cooler 22 and the heat exchanger on the downstream side of the air passage is the reheater 21, a dedicated design is possible. By applying the coating, the contact angle of water on the surface of the second fins F2 of the cooler 22 can be made smaller than that on the surface of the first fins F1 of the reheater 21 .

The embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the scope of claims.

1 high pressure pipe, 2 low pressure pipe, 3 discharge pipe, 4 suction pipe, 5 gas pipe, 6 liquid pipe, 10 outdoor unit, 11 compressor, 12 hexagonal valve, 13 outdoor heat exchanger, 14 first expansion valve, 15 sensor , 20 Indoor unit, 21 Reheater, 22 Cooler, 23 Second expansion valve, 31 Air passage, 32 Blower, 41 Four-way valve, 42 First check valve, 43 Second check valve, 44 Third check valve, 45 fourth check valve, 100 air conditioner, F1 first fin, F2 second fin, NC check valve bridge circuit, RC refrigerant circuit, RF refrigerant channel switching mechanism, T1 first heat transfer channel, T2 A second heat transfer channel.

Claims

a refrigerant circuit having a compressor, a refrigerant flow switching mechanism, an outdoor heat exchanger, a first expansion valve, a reheater, a second expansion valve, and a cooler, and configured to circulate the refrigerant;
A blower configured to blow air to the reheater and the cooler,
The refrigerant channel switching mechanism is configured to be switchable between a first switching state and a second switching state,
The refrigerant flow switching mechanism is
In the first switching state, the refrigerant circuit includes the compressor, the refrigerant flow switching mechanism, the outdoor heat exchanger, the first expansion valve, the refrigerant flow switching mechanism, the reheater, and the second It is configured such that the refrigerant is switched to flow in the order of the expansion valve, the cooler, and the refrigerant flow switching mechanism, and in the second switching state, the refrigerant circuit is switched between the compressor and the refrigerant flow. The refrigerant flows in order of the path switching mechanism, the reheater, the second expansion valve, the cooler, the refrigerant flow switching mechanism, the first expansion valve, the outdoor heat exchanger, and the refrigerant flow switching mechanism. It is configured so that it can be switched between
The reheater and the cooler are arranged such that the air blown by the blower passes through the cooler before passing through the reheater in both the first switching state and the second switching state. An air conditioner configured to
The air conditioner according to claim 1, wherein the refrigerant channel switching mechanism is a hexagonal valve.
The refrigerant flow switching mechanism has a four-way valve and a check valve bridge circuit,
The air conditioner according to claim 1, wherein said four-way valve is connected to said compressor, said outdoor heat exchanger and said check valve bridge circuit.
The reheater has a plurality of first heat transfer channels arranged in parallel,
The cooler has a plurality of second heat transfer channels arranged in parallel,
The parallel number of the plurality of second heat transfer paths of the cooler is larger than the number of parallel of the plurality of first heat transfer paths of the reheater, according to any one of claims 1 to 3. Air conditioner.
The reheater has a first fin,
The cooler has a second fin,
The water contact angle on the surface of the second fin of the cooler is smaller than the water contact angle on the surface of the first fin of the reheater. The air conditioner described in the paragraph.
an outdoor unit having the compressor and the outdoor heat exchanger;
an indoor unit having the reheater and the cooler;
high pressure pipes,
further equipped with low-pressure piping,
The air conditioner according to any one of claims 1 to 5, wherein the outdoor unit and the indoor unit are connected by the high pressure pipe and the low pressure pipe.
further comprising a sensor on a pipe connecting the first expansion valve and the refrigerant flow switching mechanism;
The air conditioner according to any one of claims 1 to 6, wherein said sensor is configured to measure the pressure or temperature of said refrigerant in said pipe.
The air conditioner according to any one of claims 1 to 7, wherein the refrigerant is a mixed refrigerant.
The air conditioner according to claim 8, wherein the reheater and the cooler are configured such that the flow of the refrigerant is countercurrent to the flow of the air.