JP7065681B2 - Air conditioner - Google Patents

Description

The present invention relates to an air conditioner.

The air conditioner is a device that absorbs heat from the outside of the building during a heating operation that heats the inside of the building and releases heat to the outside of the building during a cooling operation that cools the inside of the building. Therefore, the air conditioner includes a heat exchanger that exchanges heat between air and the refrigerant, a blower that creates an air flow, a compression device that compresses the refrigerant to a high temperature and a high pressure, and an expansion device that reduces the pressure of the refrigerant.

As a method of improving the operational stability of the air conditioner, there is a method of vaporizing the refrigerant at the outlet of the evaporator and flowing it into the compressor. However, in this case, since the heat transfer surface is in the gas phase region near the outlet of the evaporator, there is a problem that the cooling capacity is lowered.

In response to the above problems, in Patent Document 1, by heating the refrigerant at the outlet of the evaporator with the refrigerant at the outlet of the condenser, the refrigerant flowing into the compressor is vaporized and the dryness of the refrigerant at the outlet of the evaporator is reduced. The cooling capacity is increased. Further, in Patent Document 2, the refrigerant flowing out of the condenser is branched into two paths A and B, the path A is depressurized, and then heat is exchanged with the path B to evaporate the refrigerant. By merging with the refrigerant of the path B that has flowed out in the phase state, the suction refrigerant of the compressor is vaporized while increasing the cooling capacity of the evaporator.

Japanese Unexamined Patent Publication No. 9-60989 Japanese Unexamined Patent Publication No. 2002-156161

As mentioned above, the air conditioner operates in two modes, cooling and heating. For this reason, it is equipped with a four-way valve for switching the roles of the two heat exchangers of the refrigeration cycle, one to the condenser and the other to the evaporator. In the four-way valve, heat exchange occurs because the high-temperature and high-pressure refrigerant flowing from the compressor and the low-temperature and low-pressure refrigerant flowing from the evaporator flow side by side. As a result, the high temperature refrigerant is cooled by the low temperature refrigerant, resulting in a loss in cycle performance.

Considering the application of conventional techniques to a refrigeration cycle with a four-way valve, the area where the refrigerant is heated between the four-way valve outlet and the compressor suction port because the effects can be easily obtained in both cooling and heating. Will be provided. However, in this case, since the low-temperature refrigerant flowing through the four-way valve has a gas-liquid two-phase flow, heat transfer is accompanied by evaporation, and the heat transfer coefficient is high. That is, the heat loss is increased by circulating the gas-liquid two-phase flow through the four-way valve. Therefore, in order to increase the COP of the refrigeration cycle, it is necessary to make the outlet of the evaporator gas-liquid two-phase, but to make the low-pressure refrigerant flowing into the four-way valve into a gas-phase single-phase state.

Therefore, the present invention can reduce the heat loss of the four-way valve and improve the COP by heating the gas-liquid two-phase refrigerant flowing out of the evaporator to the gas-phase single phase before reaching the four-way valve. The purpose is to provide a capable air conditioner.

In order to achieve the above object, the air conditioner according to one aspect of the present invention comprises a refrigeration cycle in which a compressor, a condenser, an expansion valve, an evaporator, and a four-way valve are connected by a pipe for flowing a refrigerant. It has a first flow path between the outlet of the condenser and the inlet of the evaporator, and a second flow path between the outlet of the evaporator and the inlet of the four-way valve, and the expansion. The valve is arranged in the first flow path, and the refrigerant flowing in the second flow path is heated by the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path. Equipped with a part.

According to the present invention, it is possible to reduce the heat loss of the four-way valve and improve the COP by heating the gas-liquid two-phase refrigerant flowing out of the evaporator to the gas-phase single phase before reaching the four-way valve. A capable air conditioner can be provided.

It is a block diagram of the refrigerating cycle of the air conditioner which concerns on 1st Embodiment. It is a block diagram of the refrigerating cycle of the air conditioner of the prior art. It is a schematic diagram of the relationship between the dryness of the refrigerant inside the evaporator and the heat transfer coefficient. It is a schematic diagram of the flow inside a four-way valve in the refrigeration cycle of the prior art. It is a block diagram of the refrigerating cycle of the air conditioner which concerns on 2nd Embodiment. It is a schematic diagram of the cross section of the outdoor unit which concerns on 2nd Embodiment. It is a block diagram of the refrigerating cycle of the air conditioner which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
The air conditioner 200 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows a configuration diagram of a refrigeration cycle of the air conditioner 200 according to the first embodiment.
The air conditioner 200 shown in FIG. 1 is a home room air conditioner. The air conditioner 200 includes an indoor unit 110 for controlling the temperature inside the building, an outdoor unit 100 for receiving and radiating air from the outside of the building, a liquid phase side connecting pipe 113 connecting the indoor unit 110 and the outdoor unit 100, and air. It is provided with a phase side connection pipe 114. Inside the indoor unit 110, an indoor heat exchanger 111 and a once-through fan 112 are provided. Inside the outdoor unit 100, there are a compressor 101, a four-way valve 102, an outdoor heat exchanger 103, a propeller fan 105, a main expansion valve 104, a sub expansion valve 3, and a first heat exchange unit 4. It is provided.

This system passes through a compressor 101, a four-way valve 102, a gas phase side connection pipe 114, an indoor heat exchanger 111, a liquid phase side connection pipe 113, a first heat exchange unit 4, and a main expansion valve 104, and then exchanges outdoor heat. The main flow path 1 passing through the vessel 103, branching from between the main expansion valve 104 and the outdoor heat exchanger 103, and passing through the sub-expansion valve 3 and the first heat exchanger 4, the four-way valve 102 and the outdoor heat exchanger It is composed of an auxiliary flow path 2 that joins between 103. The entire flow path is a closed loop without an open portion, and the R32 refrigerant is sealed inside the flow path. The refrigerant may be another refrigerant such as R410a.

The valve body 26 of the four-way valve 102 can move in the left-right direction in FIG. 1 according to the operation setting. Specifically, in FIG. 1, the discharge pipe 20 and the indoor unit side pipe 22 are in a state where the suction pipe 21 and the outdoor unit side pipe 23 are in communication with each other. However, by switching the position of the valve body 26, the discharge pipe 20 The outdoor unit side pipe 23 can be switched to a state in which the suction pipe 21 and the indoor unit side pipe 22 are in communication with each other.

The main expansion valve 104 and the sub expansion valve 3 are electromagnetic expansion valves, respectively, and the opening degree of the flow path can be adjusted from fully closed to fully open by a control device (not shown). Since the sub-expansion valve 3 only needs to be able to open and close the flow path as a minimum function, an electromagnetic valve or the like can be used as a substitute.

The indoor heat exchanger 111 and the outdoor heat exchanger 103 are of a type in which air and a refrigerant exchange heat. Specifically, it is a fin tube type heat exchanger having a structure in which a heat transfer tube through which a refrigerant flows penetrates through a fin serving as an air heat transfer surface.

The first heat exchange unit 4 has a structure in which the flow path between the indoor heat exchanger 111 and the main expansion valve 104 and the flow path between the sub-expansion valve 3 and the flow path confluence point 5 are partially in contact with each other. .. Therefore, the first heat exchange unit 4 functions as a supercooling heat exchanger.

The flow path between the outlet of the indoor heat exchanger 111 and the inlet of the outdoor heat exchanger 103 is the first flow path A. The main flow path 1 constitutes a part of the first flow path A. The flow path between the outlet of the outdoor heat exchanger 103 and the inlet of the four-way valve 102 is the second flow path B. The flow path that branches from the flow path between the main expansion valve 104 and the inlet of the outdoor heat exchanger 103 in the first flow path A and is connected to the second flow path B is the third flow path C, which is a side flow. The road 2 corresponds to the third flow path C.

The operation of the refrigeration cycle will be described with respect to the air conditioner 200 according to the first embodiment.
The air conditioner 200 shown in FIG. 1 shows the connection relationship during the heating operation. The refrigerant compressed into a high-temperature and high-pressure gas phase state by the compressor 101 passes through the four-way valve 102 and then flows into the indoor heat exchanger 111. In the indoor heat exchanger 111, the refrigerant releases heat to the air flow generated by the through-flow fan 112, and the air in the building is heated. At this time, the refrigerant is cooled to change from a gas-liquid two-phase state to a liquid single-phase state. The refrigerant that has been radiated by the indoor heat exchanger 111 returns to the outdoor unit 100, is cooled by the first heat exchanger 4, and then passes through the main expansion valve 104 to enter a gas-liquid two-phase state below the outside air temperature. Reduce the pressure.

The reduced pressure refrigerant branches into the main flow path 1 and the sub flow path 2. The refrigerant in the main flow path 1 flows into the outdoor heat exchanger 103 and evaporates by receiving heat from the air flow generated by the propeller fan 105. The refrigerant in the sub-flow path 2 is heated by the first heat exchange unit 4, and then merges with the refrigerant in the main flow path 1 at the flow path confluence point 5. The refrigerant flow rate ratio between the main flow path 1 and the sub-flow path 2 is adjusted by the opening degree of the sub-expansion valve 3. The refrigerant flow rate ratio between the main flow path 1 and the sub-flow path 2 is, for example, 1: 95% for the main flow path and 2: 5% for the sub-flow path. The combined refrigerant passes through the four-way valve 102 and then returns to the suction side of the compressor 101. This closed loop continuously heats the air inside the building.

In the case of cooling operation, the valve body 26 is shifted to the right in FIG. 1, and the sub-expansion valve 3 is fully closed. As a result, the refrigerant flows in the reverse direction of the heating operation, releases heat in the outdoor heat exchanger 103, and receives heat in the indoor heat exchanger 111, so that the air inside the building is cooled. In the case of cooling operation, the auxiliary expansion valve 3 is fully closed, so that the refrigerant in the auxiliary flow path 2 does not flow.

In order to explain the effect of the air conditioner 200 according to the first embodiment, the differences from the prior art will be described.
FIG. 2 shows a configuration diagram of a refrigeration cycle of the conventional air conditioner 210. The conventional refrigeration cycle does not have the first heat exchange unit 4, the sub-expansion valve 3, and the sub-flow path 2 with respect to the air conditioner 200 of FIG. Further, since there is no sub-flow path 2, there is no flow path confluence point 5. Therefore, in the case of heating operation, the refrigerant flowing out of the main expansion valve 104 obtains heat from the outside air by the outdoor heat exchanger 103, and then flows in the order of the four-way valve 102 and the compressor 101.

FIG. 3 is a schematic diagram of the relationship between the dryness of the refrigerant and the heat transfer coefficient when the outdoor heat exchanger 103 is used as an evaporator.
In the evaporation process, the dryness of the gas-liquid two-phase refrigerant increases from the inlet to the outlet, and the proportion occupied by the gas-phase region increases toward the downstream. At this time, the heat transfer coefficient of the refrigerant drops sharply above the threshold value x of the dryness. This is because the flow mode of the refrigerant with the threshold x as the boundary changes from a cyclic flow in which the liquid phase is distributed on the wall surface of the heat transfer tube and the gas phase in the center of the heat transfer tube to a flow in which the liquid phase is distributed in the flow of the gas phase. This is because the change makes it difficult for the refrigerant to evaporate on the wall surface of the heat transfer tube. Since the threshold value x depends on the shape of the groove on the inner surface of the heat transfer tube, there is no fixed value, but the dryness is generally 0.9 to 1.0.

When the heat transfer coefficient of the refrigerant decreases, the temperature difference between the air and the refrigerant required to obtain a constant amount of exchange heat increases, but since the inflow air temperature is constant, the evaporation temperature decreases, that is, the evaporation pressure decreases. .. Therefore, as the dryness of the outlet of the outdoor heat exchanger 103 increases, the proportion of the heat transfer surface having a low heat transfer coefficient increases, and the evaporation pressure decreases. When the evaporation pressure decreases, the theoretical compression power increases due to the increase in the pressure difference from the discharge pressure, and the COP decreases due to the increase in the compressor input power.

For the above reasons, in the prior art, the outlet dryness of the outdoor heat exchanger 103 is set to less than 1 in order to maximize the COP, but in this case, there is a problem in the heat loss of the four-way valve 102.

FIG. 4 is a diagram schematically showing a flow state inside the four-way valve 102 in the prior art.
In FIG. 4, the high-temperature refrigerant discharged from the compressor 101 flows from the discharge pipe 20 to the indoor unit side pipe 22, and the outdoor heat exchanger 103 flows from the outdoor unit side pipe 23 to the suction pipe 21. It shows the state in which the refrigerant of the above flows.

Since the refrigerant flowing out of the outdoor heat exchanger 103 is a gas-liquid two-phase, the liquid-phase refrigerant 24 is distributed inside the gas-phase refrigerant 25. Here, the flow of the low-temperature refrigerant is bent 180 degrees inside the valve body 26 inside the four-way valve 102, but the liquid phase refrigerant 24 having a high density has a high inertial force, so that it adheres to the wall surface of the valve body 26 and is a liquid film. To form. When a liquid film is formed on the wall surface of the valve body 26, the heat transfer coefficient increases because the liquid film evaporates when heat is exchanged with the high-temperature refrigerant through the valve body 26. As a result, when the refrigerant on the low temperature side has two phases of gas and liquid, the amount of heat exchange increases as compared with the case of single phase of gas phase.

When the amount of heat exchange between the high temperature refrigerant and the low temperature refrigerant in the four-way valve 102 increases, the refrigerant temperature at the inlet of the indoor heat exchanger 111 decreases during the heating operation. As a result, the specific enthalpy of the refrigerant at the inlet of the indoor heat exchanger 111 decreases, so that the difference in the specific enthalpy of the inlet and outlet of the indoor heat exchanger 111 decreases, and the COP decreases due to the decrease in the heating capacity.

For the above reasons, in the prior art, the outlet of the outdoor heat exchanger 103 is in a gas-liquid two-phase state to maintain the evaporation pressure, but the heat exchange amount in the four-way valve 102 is high, so that the heating capacity is lost. Therefore, COP is reduced.

On the other hand, in the air conditioner 200 according to the first embodiment, the refrigerant branched to the sub-flow path 2 is heated to the gas phase region by the first heat exchange unit 4, and then the outdoor heat exchanger 103 flows out. It merges with the refrigerant in the main flow path 1. As a result, by adjusting the flow rate of the sub-flow path 2 using the sub-expansion valve 3, the dryness of the refrigerant of the sub-flow path 2 that has flowed out of the first heat exchange unit 4 is set to 1 or more, and the dryness is 1 or more. The refrigerant makes it possible to heat the gas-liquid two-phase refrigerant flowing out of the outdoor heat exchanger 103. As described above, in the present embodiment, the first heat exchange unit 4 and the sub-flow path 2 (third flow path C) function as the heating unit 40 for heating the refrigerant flowing in the second flow path B.

Therefore, by setting the refrigerant dryness at the outlet on the side of the sub-flow path 2 of the first heat exchanger 4 to 1 or more, the refrigerant flows into the four-way valve 102 while keeping the refrigerant dryness at the outlet of the outdoor heat exchanger 103 less than 1. The refrigerant to be used can be a gas phase single phase. Therefore, the heat transfer coefficient of the low-temperature refrigerant in the four-way valve 102 can be reduced, heat loss can be suppressed, and COP can be improved.

With the above configuration, the air conditioner 200 according to the first embodiment can improve the COP as compared with the conventional air conditioner. In addition, although this embodiment has a configuration for the purpose of obtaining an effect in the case of heating operation, it is also possible to have a configuration for the purpose of obtaining an effect in the cooling operation.

<Second embodiment>
The air conditioner 220 according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 shows a configuration diagram of a refrigeration cycle of the air conditioner 220 according to the second embodiment.
The air conditioner 220 according to the second embodiment has a sub-flow path 2 (second) between the first heat exchange unit 4 and the flow path confluence point 5 with respect to the air conditioner 200 according to the first embodiment. The point that the flow path B) passes through the second heat exchange section 6 in contact with the compressor 101, and the point that the liquid phase side distributor 30 and the gas phase side distributor 31 are provided before and after the outdoor heat exchanger 103. Is different.

The second heat exchange unit 6 has a shape in which the sub-flow path 2 is in contact with the surface of the compressor 101, and heats the refrigerant in the sub-flow path 2 by the surface of the compressor 101 having a high temperature. However, if the desired effect is obtained, there may be various configurations such as arranging a heat exchanger around the compressor 101. In the present embodiment, the first heat exchange unit 4, the sub-flow path 2 (third flow path C), and the second heat exchange unit 6 function as a heating unit 41 for heating the refrigerant flowing in the second flow path B. ..

In the case of heating operation, the refrigerant in the main flow path 1 is branched into a plurality of flow paths by the liquid phase side distributor 30, evaporated by the outdoor heat exchanger 103, and then merged by the gas phase side distributor 31. On the other hand, in the case of cooling operation, the refrigerant flowing out of the four-way valve 102 is branched into a plurality of flow paths by the gas phase side distributor 31, condensed by the outdoor heat exchanger 103, and then the liquid phase side distributor 30. Meet at.

FIG. 6 shows a schematic cross-sectional view of the outdoor unit 100.

The outdoor heat exchanger 103 includes fins 32 that serve as a heat transfer surface on the air side, and a flat heat transfer tube 33 having a plurality of holes in a flat cross section. The top and bottom of the outdoor heat exchanger 103 are closed by the housing wall surface 34 of the outdoor unit 100, and the propeller fan 105 is rotated by driving the fan motor 35 provided inside the outdoor unit 100 to rotate the propeller fan 105 from right to left in the drawing. Generates an air flow toward. The refrigerant flows inside the flat heat transfer tube 33 in the front and depth directions of the drawing. As a result, the air and the refrigerant exchange heat. Although each flat heat transfer tube 33 is connected to the liquid phase side distributor 30 and the gas phase side distributor 31 shown in FIG. 5, the detailed route is omitted.

Since the heat exchanger using the flat heat transfer tube 33 shown in FIG. 6 has a small cross-sectional area of the flow path, it is necessary to branch the refrigerant flow path and exchange heat with a plurality of refrigerant paths when using the heat exchanger. Here, when the refrigerant flow path is branched into a plurality of refrigerant paths, the flow rate or replacement of the refrigerant for each refrigerant path depends on the difference in pressure loss of each flow path, the head difference between the flow path inlet / outlet, the distribution of the inflow wind speed, and the like. Differences in calorific value may occur. Due to this, in the evaporator in which the refrigerant flow path is made into multiple refrigerant paths, depending on the conditions, a refrigerant path having a dryness of less than 1 and a refrigerant path having a dryness of 1 or more are generated on the flow path outlet side. Refrigerant paths with a dryness of 1 or more have a low heat transfer coefficient of the refrigerant, but after merging, the total dryness of all the refrigerant paths is obtained. For this reason, the evaporator outlet after merging is in a gas-liquid two-phase state, but it is possible that a dry surface is partially generated and the heat transfer coefficient is lowered. That is, if the dryness distribution at the outlet of the evaporator is non-uniform, the evaporation pressure may decrease even with the same dryness at the outlet.

Next, consider a case where the outdoor heat exchanger 103 of the second embodiment is applied to the air conditioner 200 of the first embodiment. In the first embodiment, since the space between the outlet side of the outdoor heat exchanger 103 and the four-way valve 102 is heated by the refrigerant of the sub-flow path 2, the outdoor heat exchange is performed while the inlet of the four-way valve 102 is a gas phase single phase. The dryness of the outlet of the vessel 103 can be reduced. Therefore, even if there is a slight difference in the dryness of each refrigerant path at the outlet of the outdoor heat exchanger 103, the decrease in evaporation pressure is suppressed by maximizing the amount of heat generated by the sub-flow path 2. Can be done.

However, when the non-uniformity of the refrigerant distribution is high, the amount of heat is insufficient in the configuration of the sub-flow path 2 of the first embodiment, and the heat transfer coefficient of the refrigerant decreases at the outlet of the outdoor heat exchanger 103. Refrigerant paths can occur.

On the other hand, in the air conditioner 220 of the second embodiment, the refrigerant in the sub-flow path 2 heated by the first heat exchange section 4 passes through the second heat exchange section 6, thereby passing through the compressor 101. It receives heat from and is heated to a higher temperature. Therefore, it is possible to increase the amount of heating of the second flow path B at the flow path confluence point 5 with respect to the refrigerant, and as a result, it is possible to increase the tolerance for variation in the dryness of each refrigerant path at the outlet of the outdoor heat exchanger 103. ..

With the above configuration, the air conditioner 220 according to the second embodiment can provide a system in which the COP is improved even when the refrigerant distribution becomes non-uniform.

<Third embodiment>
The air conditioner 230 according to the third embodiment of the present invention will be described with reference to FIG. 7.

FIG. 7 shows a block diagram of the refrigeration cycle of the air conditioner 230 according to the third embodiment.
The air conditioner 230 according to the third embodiment removes the sub-expansion valve 3 and the sub flow path 2 from the air conditioner 220 according to the second embodiment, and replaces the first heat exchange unit 4 with a third heat. It is a refrigeration cycle in which the exchange unit 10 is installed. The outlet of the gas phase distributor 31 is connected to the four-way valve 102 after passing through the first check valve 11, the third heat exchange section 10, and the fourth heat exchange section 16. The flow path from the outlet of the gas phase distributor 31 to the inlet of the four-way valve 102 via the first check valve 11, the third heat exchange section 10, and the fourth heat exchange section 16 is the second flow path B. Corresponds to. Further, the outdoor heat exchanger 103 and the first check valve 11 and the fourth heat exchange unit 16 and the four-way valve 102 are connected by a bypass flow path 13 via the second check valve 12. The third heat exchanger 10 is an internal heat exchanger and functions as a heating unit. Further, the configuration and function of the fourth heat exchange unit 16 are the same as those of the second heat exchange unit 6, and function as a heating unit.

In the case of heating operation, the refrigerant flows out of the gas phase side distributor 31 and then flows into the third heat exchange unit 10 via the first check valve 11 to enter the indoor heat exchanger 111 and the main expansion valve. It is heated by the refrigerant between 104. Further, the refrigerant flowing out of the third heat exchange unit 10 is heated by obtaining heat from the compressor 101 in the fourth heat exchange unit 16. As a result, as in the second embodiment, even if the dryness of each refrigerant path on the outlet side of the outdoor heat exchanger 103 varies widely, the refrigerant in each refrigerant path on the outlet side of the outdoor heat exchanger 103 is vaporized. The refrigerant flowing into the four-way valve 102 can be made into a gas phase single phase while being in a liquid two-phase state. In the case of heating operation, the refrigerant in the bypass flow path 13 does not flow due to the action of the second check valve 12.

In the case of cooling operation, the refrigerant flows out of the four-way valve 102 and then flows into the gas phase side distributor 31 via the bypass flow path 13. At this time, the flow toward the fourth heat exchange unit 16 and the third heat exchange unit 10 is blocked by the action of the first check valve 11. This makes it possible to prevent a decrease in the cooling capacity due to heating of the compressor 101 itself by the high-temperature refrigerant discharged from the compressor 101 and heating of the refrigerant flowing into the indoor unit 110 by the third heat exchange unit 10. ..

With the above configuration, the heat loss of the four-way valve 102 can be reduced while the outlet of the outdoor heat exchanger 103 is a gas-liquid two-phase flow in the heating operation, and the increase in the loss can be suppressed in the cooling operation. The above configuration is an example, and the effect can be obtained even when the fourth heat exchange unit 16 is not provided. Further, in the present embodiment, two check valves are used as a method of switching the refrigerant path during the heating operation and the cooling operation, but the flow path is directly switched by installing a three-way valve at the inlet / outlet of the bypass flow path 13. But the same effect can be obtained.

The present embodiment is not limited to the above-described embodiment. A person skilled in the art can make various additions and changes within the scope of the present embodiment.

1: Main flow path, 2: Sub flow path, 4: 1st heat exchange section, 6: 2nd heat exchange section, 10: 3rd heat exchanger, 13: Bypass flow path, 16: 4th heat exchange section, 30 : Liquid phase distributor, 31: Gas phase distributor, 33: Flat heat transfer tube, 40, 41: Heating unit, 100: Outdoor unit, 101: Compressor, 102: Four-way valve, 103: Outdoor heat exchanger , 104: Main expansion valve, 110: Indoor unit, 111: Indoor heat exchanger, 200, 220, 230: Air conditioner, A: 1st flow path, B: 2nd flow path, C: 3rd flow path

Claims (6)

Compressors, condensers, expansion valves, evaporators, and four-way valves are connected by pipes for flowing refrigerant to form a refrigeration cycle.
The first flow path between the outlet of the condenser and the inlet of the evaporator, the second flow path between the outlet of the evaporator and the inlet of the four-way valve, and the expansion in the first flow path. It has a third flow path that branches off from the flow path between the valve and the inlet of the evaporator and is connected to the second flow path .
The expansion valve is arranged in the first flow path.
A heating unit that heats the refrigerant flowing through the second flow path with the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path.
A first heat exchange unit that exchanges heat between the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path and the refrigerant flowing through the third flow path.
A second heat exchange section that exchanges heat between the refrigerant flowing in the third flow path and the compressor on the second flow path side of the first heat exchange section in the third flow path. Prepare ,
The first heat exchange section and the third flow path function as the heating section for heating the refrigerant flowing through the second flow path.
The second heat exchange unit functions as the heating unit that heats the refrigerant flowing through the second flow path.
An air conditioner that forms a refrigeration cycle by setting the refrigerant at the outlet of the evaporator in a gas-liquid two-phase state and by setting the inlet of the four-way valve in a gas-phase state by the heating unit . Compressors, condensers, expansion valves, evaporators, and four-way valves are connected by pipes for flowing refrigerant to form a refrigeration cycle.
It has a first flow path between the outlet of the condenser and the inlet of the evaporator, and a second flow path between the outlet of the evaporator and the inlet of the four-way valve.
The expansion valve is arranged in the first flow path.
A heating unit that heats the refrigerant flowing through the second flow path with the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path.
A third heat exchange unit that exchanges heat between the refrigerant flowing through the second flow path and the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path.
A fourth heat exchange unit that exchanges heat between the refrigerant flowing in the second flow path and the compressor is provided on the four-way valve side of the third heat exchange unit in the second flow path. ,
The third heat exchange unit functions as the heating unit that heats the refrigerant flowing through the second flow path.
The fourth heat exchange unit functions as the heating unit that heats the refrigerant flowing through the second flow path.
An air conditioner that forms a refrigeration cycle by setting the refrigerant at the outlet of the evaporator in a gas-liquid two-phase state and by setting the inlet of the four-way valve in a gas-phase state by the heating unit . Compressors, condensers, expansion valves, evaporators, and four-way valves are connected by pipes for flowing refrigerant to form a refrigeration cycle.
It has a first flow path between the outlet of the condenser and the inlet of the evaporator, and a second flow path between the outlet of the evaporator and the inlet of the four-way valve.
The expansion valve is arranged in the first flow path.
A heating unit that heats the refrigerant flowing through the second flow path with the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path.
A third heat exchange unit that exchanges heat between the refrigerant flowing through the second flow path and the refrigerant flowing between the outlet of the condenser and the inlet of the expansion valve in the first flow path.
Branching from the flow path between the outlet of the evaporator and the inlet of the third heat exchange section in the second flow path, the outlet of the third heat exchange section and the inlet of the four-way valve in the second flow path. A bypass flow path that joins the flow path between and
The third heat exchange unit functions as the heating unit that heats the refrigerant flowing through the second flow path.
An air conditioner that forms a refrigeration cycle by setting the refrigerant at the outlet of the evaporator in a gas-liquid two-phase state and by setting the inlet of the four-way valve in a gas-phase state by the heating unit . The air conditioner according to any one of claims 1 to 3 , wherein the refrigerant flow path of the evaporator has a plurality of branches. The air conditioner according to claim 4 , wherein the refrigerant flow path in the evaporator has a shape having a substantially flat cross section and a plurality of holes. The air conditioner according to any one of claims 1 to 5 , wherein the condenser is an indoor heat exchanger provided in the indoor unit, and the evaporator is an outdoor heat exchanger provided in the outdoor unit. ..

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