JPH0587426A - Air-conditioner - Google Patents

Abstract

PURPOSE:To increase the refrigerant circulation rate of flow during defrosting by providing a bypass circuit through which high temperature, high pressure refrigerant gas is bypassed to an indoor side heat exchanger, and a bypass circuit leading from a receiver tank to the suction side of a compressor via a capillary. CONSTITUTION:A first bypass circuit 8 branches off from the inlet of a four-way valve 2 on the suction side of a compressor 1 and is connected between an outdoor side heat exchanger 6 and an expansion valve 4 via a first solenoid valve 7, so that hot gas from the compressor 1 can be directly led to the outdoor side heat exchanger 6 to stimulate defrosting of the heat exchanger 6 when defrosting of the heat exchanger 6 is carried out during heating operation. In this case, a second bypass circuit 11 leading from the receiver tank 5 to the suction side of the compressor via a second solenoid valve 9 and a capillary 10 is formed to send liquid refrigerant stored in a room side heat exchanger 3 and the receiver tank 5 to the suction side of the compressor 1 so that the refrigerant circulation rate of flow is increased to stimulate defrosting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to defrosting of an air conditioner during heating operation.

[0002]

2. Description of the Related Art Conventionally, in a refrigerant circuit of an air conditioner, as shown in FIG. 2, an indoor heat exchanger 3 and an expansion valve 4 are provided in order to improve a heating coefficient of performance (COP) during heating operation. A receiver tank 5 is provided between them to store the liquid refrigerant cooled by heat exchange with the indoor air by the indoor heat exchanger 3 to make the amount of the refrigerant passing through the expansion valve 4 appropriate so that the compressor 1 The heating capacity is improved by speeding up circulation. When the outdoor heat exchanger 6 is frosted during the heating operation, the heat exchange efficiency is reduced. Therefore, the outdoor heat exchanger 6 is defrosted. At this time, in order to avoid the temperature drop of the indoor heat exchanger 3. , The flow of the refrigerant is branched from the discharge side of the compressor 1, part of which is used for the indoor heat exchanger 3 and the other is used for the inlet of the outdoor heat exchanger 6 by the first bypass circuit 8 and the first solenoid valve 7 Compressed high-temperature gas is caused to flow from the compressor 1 through the to defrost in a short time to prevent the temperature of the indoor heat exchanger 3 from decreasing. At this time, the high-temperature and high-pressure refrigerant gas from the compressor 1 is divided into the first bypass circuit 8 and the indoor heat exchanger 3 and flows,
At the confluence of the inlets of the outdoor heat exchanger 6, the pressure of the refrigerant gas flowing through the first bypass circuit 8 is high, and the indoor heat exchanger 3
When the defrosting time is prolonged, the refrigerant gas flows backward to the indoor heat exchanger 3 to suppress the refrigerant gas flow from the indoor heat exchanger 3, and the liquid refrigerant accumulates in the indoor heat exchanger 3 and the receiver tank 5. This causes a problem of lowering the temperature of the inner heat exchanger 3 and lowering the heating state of the room.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and is an air conditioner for preventing excessive liquid refrigerant from accumulating in the indoor heat exchanger or the receiver tank during defrosting. Is intended to provide.

[0004]

In order to achieve the above object, a second bypass circuit is formed from a receiver tank to a suction side of a compressor via a second solenoid valve and a capillary to form a second bypass circuit. The second solenoid valve was opened so that the refrigerant in the receiver tank was sent to the suction side of the compressor via the capillary.

[0005]

According to the above construction, the second bypass circuit connecting from the receiver tank to the suction side of the compressor is formed, and the liquid refrigerant staying in the receiver tank during defrosting increases and flows to the indoor heat exchanger. , When the temperature of the indoor heat exchanger decreases, the second solenoid valve is opened, the accumulated liquid refrigerant is returned to the suction side of the compressor through the capillary, the circulation amount of the refrigerant is increased, and the liquid accumulated in the receiver tank is retained. By reducing the amount of refrigerant, it is possible to prevent a decrease in indoor temperature even if the defrosting time is prolonged.

[0006]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a refrigerant circuit diagram showing details of the present invention, in which a refrigerant gas compressed to a high temperature and high pressure by a compressor 1 has a four-way valve 2
Is switched to "heating" and sent to the indoor heat exchanger 3, where it is cooled by exchanging heat with the indoor air by the indoor heat exchanger 3 and branched between the indoor heat exchanger 3 and the expansion valve 4. The excess liquefied refrigerant is stored in the receiver tank 5 provided by the above, and is decompressed through the expansion valve 4 to be vaporized and enter the outdoor heat exchanger 6 to exchange heat with the outdoor air and the compressor 1 by the four-way valve 2. It circulates in the route returning to the suction side of. Further, a first bypass circuit 8 that branches from the inlet portion of the discharge-side four-way valve 2 of the compressor 1 and is connected between the outdoor heat exchanger 6 and the expansion valve 4 via the first electromagnetic valve 7 is provided. When the outdoor heat exchanger 6 is provided and defrosted by performing frosting during the heating operation, the first electromagnetic valve 7 is opened to allow hot gas from the compressor 1 to directly flow to the outdoor heat exchanger 6, The defrosting of the outdoor heat exchanger 6 is accelerated. In the present invention, further, the second bypass circuit 11 connected to the suction side of the compressor 1 is formed from the receiver tank 5 through the second electromagnetic valve 9 and the capillary 10. When defrosting is performed by opening the first solenoid valve 7 by the first bypass circuit 8, the hot gas from the compressor 1 is shunted to the indoor heat exchanger 3 and the first bypass circuit 8, but the fluid resistance increases. Flow mainly through the first bypass circuit 8 having a small amount of heat, and slightly flow toward the indoor heat exchanger 3 side. In the vicinity of the inlet of the outdoor heat exchanger 6 and the outlet of the first bypass circuit 8, the pressure of the hot gas from the first bypass circuit 8 becomes high, and the hot gas from the indoor heat exchanger 3 passing through the expansion valve 4 is discharged. Refrigerant gas is prevented from flowing in and flows backward, and the liquefied refrigerant gas is retained in the receiver tank 5 and the indoor heat exchanger 3 to lower the temperature of the indoor heat exchanger 3 and lower the indoor heating state. At this time, the second solenoid valve 9 of the receiver tank 5 is opened, and the liquefied refrigerant gas in the receiver tank 5 and the indoor heat exchanger 3 is sent to the suction side of the compressor 1 through the capillary 10 to receive the receiver tank 5. And reducing the refrigerant gas staying in the indoor heat exchanger 3 to increase the circulation amount of the refrigerant to prevent the temperature of the indoor heat exchanger 3 from decreasing and at the same time increase the refrigerant gas pressure on the suction side of the compressor 1. Thereby, the load of the compressor 1 can be reduced and the efficiency of the compressor 1 can be improved.

[0007]

As described above, according to the present invention, the second bypass circuit is provided so as to be connected from the receiver tank to the suction side of the compressor, and the indoor heat exchanger and the receiver tank are provided through the second bypass circuit during defrosting. By sending the staying liquid refrigerant to the suction side of the compressor and increasing the amount of refrigerant circulation, defrosting by the first bypass circuit is accelerated and the flow of refrigerant hot gas is also secured on the indoor heat exchanger side. , The indoor heating environment can be maintained. At the same time, by increasing the refrigerant gas pressure on the suction side of the compressor, it is possible to reduce the load on the compressor and improve the efficiency of the compressor.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing details of the present invention.

FIG. 2 is a refrigerant circuit diagram showing details of a conventional example.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Expansion valve 5 Receiver tank 6 Outdoor heat exchanger 7 First solenoid valve 8 First bypass circuit 9 Second solenoid valve 9 10 Capillary 11 Second bypass circuit

Claims (1)

[Claims] 1. A compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are sequentially connected, and a receiver tank is provided between the indoor heat exchanger and the expansion valve. An air conditioner comprising a first bypass circuit for bypassing a high-temperature high-pressure refrigerant gas from an outlet-side four-way valve inlet via a first electromagnetic valve to an outdoor heat exchanger, wherein the receiver tank is connected to a second side of the receiver tank. A second bypass circuit that connects to the suction side of the compressor via the solenoid valve and the capillary of the above is formed, and the second solenoid valve is opened during defrosting, and the refrigerant in the receiver tank is passed through the capillary to the suction side of the compressor. An air conditioner characterized by being sent out.