JP2000161820A - Air-conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure an overcooled region at the entrance side of a throttling device and utilize condensation heat at the overcooled region for improving operating efficiency, by providing the condenser between an indoor heat exchanger and the throttling device, arranging the condenser and the indoor heat exchanger so that heat can be exchanged, and feeding a refrigerant to the condenser in heating operation. SOLUTION: In cooling operation, a refrigerant from a compressor 10 is guided to an outdoor heat exchanger 30 via a four-way valve 20, the pressure of the refrigerant being condensed here is reduced by a throttling device 40 and then is guided to an indoor heat exchanger 50. Then, the evaporated refrigerant that has cooled indoor air is returned to the compressor 10. On the other hand, in heating operation, a refrigerant from the compressor 10 is condensed by cooling using the indoor heat exchanger 50 and then is guided to the throttling device 40 via a bypass circuit 61D, a condenser 90, and the like. After that, the refrigerant whose pressure has been reduced is returned to the compressor 10 via an outdoor heat exchanger 30. In this manner, by feeding the refrigerant to the condenser 90 in heating operation, the overcooled region at the entrance side of the throttling device 40 is ensured, and condensation heat at the overcooled region is utilized for the outdoor heat exchanger 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of performing a heating operation.

[0002]

2. Description of the Related Art In recent years, from the standpoint of protecting the global environment, it has become important to reduce the energy consumption of electrical equipment, and it is particularly important to increase the efficiency of air conditioners that consume large amounts of power among consumer electrical equipment. I have. In order to improve the heating performance of the air conditioner, conventionally, the size of the indoor heat exchanger has been increased or the path has been changed to achieve higher performance. However, even if an attempt is made to improve the performance in order to improve the heating performance, recent air conditioners have achieved higher performance because the outlet temperature of the indoor heat exchanger is close to the indoor temperature. However, the supercooled liquid increases, the liquid refrigerant region having a low heat transfer coefficient increases, and it is not possible to achieve remarkable high performance. That is, in the past, the temperature level, which is the operating point of the condenser, was set to 42 degrees,
Recently, it has been set to 39 degrees. At this time, the temperature of the supercooled area in the case of 42 degrees is 25 degrees,
The temperature of the supercooling zone in the case of 9 degrees is 22 degrees. Since the indoor air-conditioning temperature under the heating standard air-conditioning condition is 20 degrees, the temperature difference from the indoor air-conditioning temperature in the supercooling region when the temperature level which is the operating point of the condenser is 39 degrees is only 2 degrees. Therefore, in order to always secure a supercooling region of the condenser in order to secure a sufficient enthalpy, the capacity of the indoor heat exchanger must be increased. However, since the temperature difference in the supercooling region is only two degrees, there is a problem that even if the capacity of the indoor heat exchanger is increased, it hardly contributes to the heating effect. In addition, the refrigerant on the outlet side of the condenser,
It has been proposed to exchange heat with the refrigerant on the outlet side of the evaporator or the refrigerant on the suction side of the compressor to ensure supercooling of the condenser (for example, Japanese Patent Application Laid-Open Nos. Hei 6-213518 and Hei 9). -152204). However, these are
An object of the present invention is to solve the problem of a decrease in heat transfer performance peculiar to a mixed refrigerant when a mixed refrigerant is used as the refrigerant. Further, it has been proposed to exchange heat between the refrigerant on the outlet side of the condenser and the refrigerant on the discharge side of the compressor (JP-A-10-8).
No. 9794). However, this aims at further reducing the heating capacity by lowering the temperature of the refrigerant introduced into the indoor heat exchanger.

[0003]

SUMMARY OF THE INVENTION As described above,
In recent air conditioners, the outlet temperature of the indoor heat exchanger is close to the indoor temperature. Refrigerant area increases, and remarkable performance improvement cannot be achieved.

Accordingly, the present invention secures a subcooling area on the inlet side of the expansion device to increase the enthalpy without increasing the performance of the indoor heat exchanger, and further increases the heat of condensation in the subcooling area. It is an object of the present invention to further improve the operation efficiency and reduce the power consumption by utilizing the evaporator.

[0005]

According to the first aspect of the present invention, there is provided an air conditioner having a refrigeration cycle in which a compressor, an indoor heat exchanger, a throttling device, and an outdoor heat exchanger are connected in a ring by piping. A harmony device, wherein a condenser is provided between the indoor heat exchanger and the expansion device, and the condenser and the outdoor heat exchanger are disposed so as to be capable of exchanging heat. It is characterized by flowing a refrigerant. According to a second aspect of the present invention, in the air conditioner according to the first aspect, a first check valve for preventing a flow of a refrigerant during a heating operation is provided between the expansion device and the indoor heat exchanger. Wherein a bypass circuit is provided in parallel with the first check valve, and the bypass circuit is provided with the condenser and a second check valve for preventing a flow of refrigerant during a cooling operation. I do. According to a third aspect of the present invention, in the air conditioner according to the first aspect, the condenser is provided on a refrigerant inlet side during a heating operation of the outdoor heat exchanger. According to a fourth aspect of the present invention, in the air conditioner according to the first aspect, the condenser includes:
It is provided on the windward side of the outdoor heat exchanger.
According to a fifth aspect of the present invention, in the air conditioner of the first aspect, the condenser is provided at a central portion of the outdoor heat exchanger. The present invention of claim 6 is the first aspect of the present invention.
Wherein the same fins are provided in a pipe forming the condenser and a pipe forming the outdoor heat exchanger. According to a seventh aspect of the present invention, in the air conditioner of the first aspect, a part of a pipe constituting the outdoor heat exchanger is used as the condenser. The present invention of claim 8 is the invention of claim 7
In the air conditioner described in (1), among the pipes constituting the outdoor heat exchanger, a pipe adjacent to a refrigerant outlet side pipe during a heating operation is not used as the condenser. According to a ninth aspect of the present invention, in the air conditioner according to the first aspect, when a plurality of pipes constituting the outdoor heat exchanger are arranged in a flow direction of air, the pipes are arranged on the windward side. Is used as the condenser. According to a tenth aspect of the present invention, in the air conditioner according to the ninth aspect, when a plurality of pipes constituting the outdoor heat exchanger are arranged, pipes that are not adjacent to each other in the step direction are connected to the condenser. It is characterized by using as.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a first embodiment of the present invention, a condenser is provided between an indoor heat exchanger and a throttle device, and the condenser and the outdoor heat exchanger are arranged so as to be able to exchange heat. In addition, the refrigerant flows into the condenser during the heating operation. According to the present embodiment, a supercooling area can be secured by exchanging heat with the outdoor heat exchanger of the condenser, and the heat of condensation can be used for the outdoor heat exchanger.

[0007] A second embodiment of the present invention is a first embodiment.
In the embodiment, a first check valve for preventing the flow of the refrigerant during the heating operation is provided between the expansion device and the indoor heat exchanger, and a bypass circuit is provided in parallel with the first check valve. ,
This bypass circuit is provided with a condenser and a second check valve for preventing the flow of the refrigerant during the cooling operation. According to the present embodiment, in the air-conditioning apparatus capable of cooling and heating, the use of two check valves allows the refrigerant to flow to the condenser only during the heating operation.

[0008] A third embodiment of the present invention is the first embodiment.
In the embodiment, the condenser is provided on the refrigerant inlet side during the heating operation of the outdoor heat exchanger. According to the present embodiment, by performing heat exchange with the inlet side of the outdoor heat exchanger in this way, the direct influence on the superheated area on the outlet side of the outdoor heat exchanger is reduced, and the balance of the superheated area is reduced. Collapse can be prevented.

A fourth embodiment of the present invention is directed to the first embodiment.
In the above embodiment, the condenser is provided on the windward side of the outdoor heat exchanger. According to the present embodiment, by providing the condenser on the windward side, the heat of condensation can be effectively transmitted to the outdoor heat exchanger on the leeward side.

[0010] A fifth embodiment of the present invention is a first embodiment.
In the embodiment, the condenser is provided at the center of the outdoor heat exchanger. According to the present embodiment, by performing heat exchange with the central portion of the outdoor heat exchanger in this manner, the direct effect on the superheated area on the outlet side of the outdoor heat exchanger is reduced, and the balance of the superheated area is reduced. Collapse can be prevented, and heat can be exchanged in places where the wind speed distribution is high, so that the heat of condensation can be effectively transmitted to the outdoor heat exchanger.

A sixth embodiment of the present invention is directed to the first embodiment.
In this embodiment, the same fins are provided in a pipe constituting a condenser and a pipe constituting an outdoor heat exchanger. According to the present embodiment, since the same fin is used, the heat of condensation is easily transmitted to the outdoor heat exchanger.

A seventh embodiment of the present invention is directed to the first embodiment.
In this embodiment, a part of the piping constituting the outdoor heat exchanger is used as a condenser. According to the present embodiment, the heat of condensation is easily transmitted to the outdoor heat exchanger.

An eighth embodiment of the present invention relates to a seventh embodiment.
In the embodiment, of the pipes constituting the outdoor heat exchanger, pipes adjacent to the refrigerant outlet side pipe during the heating operation,
It is not used as a condenser. According to the present embodiment, it is possible to reduce the direct influence on the superheated area on the outlet side of the outdoor heat exchanger, and prevent the balance of the superheated area from being lost.

The ninth embodiment of the present invention is the first embodiment.
In the embodiment, when a plurality of pipes constituting the outdoor heat exchanger are arranged in the direction of air flow, a part of the pipes arranged on the windward side is used as a condenser. According to the present embodiment, by providing the condenser on the windward side, the heat of condensation can be effectively transmitted to the outdoor heat exchanger on the leeward side.

[0015] In a tenth embodiment of the present invention, in the ninth embodiment, when a plurality of pipes constituting the outdoor heat exchanger are arranged, pipes not adjacent to each other in the step direction are condensed. It is used as a container. According to the present embodiment, the heat of condensation can be effectively transmitted to the outdoor heat exchanger.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioner according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a refrigeration cycle diagram of the air conditioner for explaining the first embodiment. As shown in the figure, the compressor 10, the four-way valve 20, the outdoor heat exchanger 30, the expansion device 40, and the indoor heat exchanger 50 are connected in a ring shape through respective pipes. Here, the compressor 10,
The four-way valve 20, the outdoor heat exchanger 30, and the expansion device 40 are provided in the outdoor unit A, and the indoor heat exchanger 50 is provided in the indoor unit B.

The outdoor unit A and the indoor unit B are connected to the liquid side connection pipe 6.
1C and the gas-side connection pipe 62C. The liquid side connection pipe 61C is connected by a liquid side outdoor valve 81 and a liquid side indoor valve 82, and the gas side connection pipe 62C is connected by a gas side outdoor valve 83 and a gas side indoor valve 84. The liquid side pipe 61A connects the outdoor heat exchanger 30 and the throttle device 40, and the liquid side pipe 61B connects the throttle device 40 and the liquid side outdoor valve 81. The gas-side pipe 62A connects the four-way valve 20 and the outdoor heat exchanger 30.

As shown in FIG. 1, a first check valve 71 for preventing the flow of the refrigerant during the heating operation is provided in the liquid side pipe 61B. A bypass circuit 61D is provided in parallel with the first check valve 71. The bypass circuit 61D is provided with a condenser 90 and a second check valve 72 for preventing the flow of the refrigerant during the cooling operation. The outdoor heat exchanger 30 includes the outdoor blower 3 and the indoor heat exchanger 50.
Is provided with an indoor blower 5. The condenser 90 is arranged to be able to exchange heat with the outdoor heat exchanger 30. At this time, it is preferable that the condenser 90 is arranged on the windward side of the outdoor heat exchanger 30. By providing the condenser 90 on the windward side, the heat of condensation of the condenser 90 can be easily used in the outdoor heat exchanger 30. Further, as shown in the figure, it is preferable to provide on the side where the refrigerant flows in the heating operation. By thus providing the refrigerant on the refrigerant inflow side of the outdoor heat exchanger 30, the balance of the superheated region is not lost.

Switching between the cooling operation and the heating operation is performed by switching the four-way valve 20 to change the flow of the refrigerant. In the drawing, the arrow indicated by a solid line indicates the flow direction of the refrigerant during the cooling operation, and the arrow indicated by the broken line indicates the flow direction of the refrigerant during the heating operation. During the cooling operation, the outdoor heat exchanger 30 functions as a condenser, and the indoor heat exchanger 50 functions as an evaporator. During the heating operation, the indoor heat exchanger 50 functions as a condenser, and the outdoor heat exchanger 30 functions as an evaporator.

Hereinafter, the flow of the refrigerant will be described. First, the refrigerant flow in the cooling operation will be described. Compressor 1
The refrigerant compressed at 0 is guided to the outdoor heat exchanger 30 through the four-way valve 20. The refrigerant condensed in the outdoor heat exchanger 30 is depressurized by the expansion device 40 through the liquid-side pipe 61A, and guided to the indoor heat exchanger 50 through the first check valve 71 and the liquid-side connection pipe 61C. . The refrigerant evaporated in the indoor heat exchanger 50 is sucked into the compressor 10 through the gas-side connection pipe 62C and the four-way valve 20.

Next, the refrigerant flow in the heating operation will be described. The refrigerant compressed by the compressor 10 is guided to the indoor heat exchanger 50 through the four-way valve 20. The refrigerant condensed in the indoor heat exchanger 50 is guided to the expansion device 40 through the liquid-side connection pipe 61C, the bypass circuit 61D, the condenser 90, and the second check valve 72. The refrigerant decompressed by the expansion device 40 passes through the liquid-side pipe 61A, and passes through the outdoor heat exchanger 3
It is led to 0. The refrigerant evaporated in the outdoor heat exchanger 30 is sucked into the compressor 10 through the gas connection pipe 62A. Here, during the heating operation, the indoor heat exchanger 50
The refrigerant on the outlet side of the supercooled (about 17 deg) liquid refrigerant (about 2
2 degrees), and is controlled so as to be a gas-liquid two-layer region (about 39 degrees). By controlling in this manner, the indoor heat exchanger 50
The heat exchanger performance (heat transferability) can be improved by increasing the latent heat area in the heat exchanger. Then, in the condenser 90, heat is condensed and released in the ambient temperature of the outside air (wet bulb / dry bulb temperature: 7/6 degrees) to form a supercooled liquid refrigerant. At this time, the condenser 90
By allowing the outdoor heat exchanger 30 to absorb the heat of condensation from
Evaporation performance is also improved, and frost formation in the outdoor heat exchanger 30 can be prevented under low-temperature heating conditions (wet bulb / dry bulb temperature: 2/1 degree). Note that, as described above, the condenser 9
At 0, enthalpy will increase due to increased supercooling.

Next, an air conditioner according to another embodiment of the present invention will be described with reference to FIGS. The members having the same functions as those of the embodiment shown in FIG. In the embodiment shown in FIG. 2, the condenser 90 is provided at the center of the outdoor heat exchanger 30. By arranging the condenser 90 at a position where the wind speed distribution by the outdoor blower 3 is high, the release of the condensation heat from the condenser 90 can be promoted, and the condensation heat can be effectively used for the outdoor heat exchanger 30. can do. Further, by providing the heat exchanger in the center of the outdoor heat exchanger 30 in this way, the balance of the superheated area on the outlet side of the outdoor heat exchanger 30 is not broken.

In the embodiment shown in FIG. 3, a part of the pipe of the outdoor heat exchanger 30 is used as a condenser. FIG. 3 shows only members different from those in FIG. 1, and other omitted members are the same as those in FIG. As shown in the figure, the pipes constituting the outdoor heat exchanger 30 are arranged in two rows in the direction of air flow. On the windward side of the outdoor heat exchanger 30, the pipes 31A, 31A
31H are arranged on the leeward side in the order from the refrigerant inflow side to the pipes 32A, 32B, 32C,.
H is arranged. Here, the pipe 31B and the pipe 31E constituting the outdoor heat exchanger 30 are used as the evaporator 90. The refrigerant introduced from the liquid side pipe 61A is
A and a branch to the pipe 32A. The refrigerant branched to the pipe 31A is a pipe 31C, a pipe 32D, a pipe 32E, a pipe 3
The gas flows sequentially through 2F, 31G, 32G, 31H, and 32H, and is led out to the gas-side pipe 62A. On the other hand, the refrigerant branched to the pipe 32A is a pipe 32B, a pipe 32C, a pipe 31D,
It flows through the pipe 31F in order and joins the pipe 31G. In addition,
The refrigerant from the bypass circuit 61D flows from the pipe 31E to the pipe 31B. The condenser 90 includes the pipe 31E and the pipe 31B. In the present embodiment, some of the pipes 31E and 31B constituting the outdoor heat exchanger 30 as described above are used.
Is used as the condenser 90, so that they are connected by the same fin, so that heat exchange can be easily performed. Further, by using the pipes 31E and 31B arranged on the windward side as the condenser 90, the heat of condensation can be easily used for the heat of evaporation. Therefore,
The piping used as the condenser 90 is preferably the windward piping 31. Further, it is preferable that the pipes 31H and 32G adjacent to the refrigerant outlet pipe 32H are not used as the condenser 90. This is because the influence on the outlet pipe 32H of the refrigerant may cause the balance of the overheated area to be lost. Further, as in this embodiment, by using non-adjacent pipes as the pipes of the condenser 90, the heat of condensation can be easily used for the heat of evaporation.

The embodiment shown in FIG. 4 also uses part of the piping of the outdoor heat exchanger 30 as a condenser. Note that FIG. 4 also shows only members different from FIG. 1 as in FIG. As shown in the figure, the pipes constituting the outdoor heat exchanger 30 are arranged in two rows in the direction of air flow. On the leeward side of the outdoor heat exchanger 30, pipes 31A, 31B, 31C,... 31F are arranged in order from the refrigerant inflow side, and on the leeward side, pipes 32A,
32F are arranged. Downstream of the pipes 32D and 32E, the pipes 33D and 3
3E is additionally provided. Here, the outdoor heat exchanger 30
Are used as the evaporator 90. The refrigerant introduced from the liquid side pipe 61A is branched into a pipe 31A and a pipe 32A. The refrigerant branched to the pipe 31A is a pipe 31B, a pipe 32C, a pipe 33D,
The gas flows sequentially through the pipe 32E, the pipes 33E, 31F, and 32F, and is led out to the gas-side pipe 62A. On the other hand, the refrigerant branched to the pipe 32A is the pipe 32B, the pipe 31C, and the pipe 32.
D and flow sequentially to join the pipe 32E. The refrigerant from the bypass circuit 61D flows from the pipe 31E to the pipe 31D.
Flows to The condenser 90 is connected to the pipe 31E and the pipe 31D.
Composed of In the present embodiment, since some of the pipes 31E and 31D constituting the outdoor heat exchanger 30 are used as the condenser 90 as described above, they are connected by the same fin and heat exchange can be easily performed. In addition, by using the pipes 31E and 31D arranged on the windward side as the condenser 90, the heat of condensation can be easily used for the heat of evaporation. Therefore, the piping used as the condenser 90 is preferably the piping 31 on the windward side. In addition, the pipe 31 adjacent to the refrigerant outlet pipe 32F
It is preferable not to use F and 32E as the condenser 90. This is because the influence on the outlet pipe 32F of the refrigerant may cause the balance of the overheated area to be lost.

[0025]

As described above, according to the present invention, without increasing the performance of the indoor heat exchanger, the enthalpy is increased by securing a supercooling area on the inlet side of the expansion device. By utilizing the condensation heat in the region for the evaporator, it is possible to further improve the operation efficiency and reduce the power consumption.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner according to one embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of an air conditioner according to another embodiment of the present invention.

FIG. 3 is a refrigeration cycle diagram of a main part of an air conditioner according to another embodiment of the present invention.

FIG. 4 is a refrigeration cycle diagram of a main part of an air conditioner according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Compressor 20 Four-way valve 30 Outdoor heat exchanger 40 Throttle device 50 Indoor heat exchanger 61D Bypass circuit 71 Check valve 72 Second check valve 90 Condenser

Claims (10)

[Claims] 1. An air conditioner having a refrigeration cycle in which a compressor, an indoor heat exchanger, a throttle device, and an outdoor heat exchanger are connected in a ring by a pipe, wherein the indoor heat exchanger and the throttle device are connected to each other. An air conditioner, comprising: a condenser provided between the condenser and the outdoor heat exchanger so that heat can be exchanged between the condenser and the outdoor heat exchanger; and a refrigerant flows through the condenser during a heating operation. 2. A first check valve for preventing a flow of refrigerant during a heating operation is provided between the expansion device and the indoor heat exchanger, and a bypass circuit is provided in parallel with the first check valve. Provided,
2. The air conditioner according to claim 1, wherein the bypass circuit includes the condenser and a second check valve that prevents a flow of a refrigerant during a cooling operation. 3. 3. The condenser according to claim 1, wherein the condenser is provided on a refrigerant inlet side of the outdoor heat exchanger during a heating operation.
An air conditioner according to item 1. 4. The air conditioner according to claim 1, wherein the condenser is provided on the windward side of the outdoor heat exchanger. 5. The air conditioner according to claim 1, wherein the condenser is provided at a central portion of the outdoor heat exchanger. 6. The air conditioner according to claim 1, wherein the same fin is provided in a pipe forming the condenser and a pipe forming the outdoor heat exchanger. 7. The condenser according to claim 1, wherein a part of a pipe constituting the outdoor heat exchanger is used as the condenser.
An air conditioner according to item 1. 8. The air conditioner according to claim 7, wherein, of the pipes constituting the outdoor heat exchanger, a pipe adjacent to a refrigerant outlet pipe during a heating operation is not used as the condenser. apparatus. 9. When the pipes constituting the outdoor heat exchanger are arranged in a plurality of rows in the flow direction of air, a part of the pipes arranged on the windward side is used as the condenser. The air conditioner according to claim 1, wherein 10. When the pipes constituting the outdoor heat exchanger are arranged in a plurality of stages, pipes that are not adjacent to each other in a step direction are used as the condenser.
An air conditioner according to item 1.