JPS6230697Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is designed to heat-exchange the liquid refrigerant of the evaporator generated by the defrosting operation of the main refrigerant circuit with the discharge gas of the auxiliary refrigerant circuit, vaporize it, and return it to the main compressor. The purpose is to prevent liquid compression due to liquid returning to the tank.

The present invention will be explained below based on the embodiment shown in the drawings.

1 is the main compressor, 2 is the three-way switching valve, 3 is the condenser,
4 is a check valve, 5 is a first heat exchanger, 6 is an expansion valve, 7
8 is an evaporator, 9 is a second on-off valve, and 10 is a third on-off valve provided in parallel with the second on-off valve 9, as well as a first on-off valve 11 and a suction pressure regulating valve. 12, and these are connected in sequence to form a main refrigerant circuit. Further, 13 is a sub-compressor, and the second heat exchanger 1
0 and 14 are auxiliary condensers, 15 is a second expansion valve, and the first heat exchanger 5 are sequentially connected to perform high-temperature evaporation (e.g.
It constitutes an auxiliary refrigerant circuit (ET approximately 10℃). Further, the main refrigerant circuit and the high-temperature evaporation auxiliary refrigerant circuit are in a heat exchange relationship through first and second heat exchangers 5 and 10.

In the refrigeration cycle configured in this way,
During the cooling operation, the high-temperature, high-pressure refrigerant discharged from the main compressor 1 of the main refrigerant circuit is cooled in the condenser 3 via the three-way switching valve 2, and then reaches the first heat exchanger 5 via the check valve 4. After being supercooled by heat exchange with the low-temperature, low-pressure refrigerant gas in the auxiliary refrigerant circuit, the pressure is reduced by the expansion valve 6, enters the evaporator 8, becomes low-temperature, low-pressure refrigerant gas, and passes through the second on-off valve 9 to the main compressor. Return to 1.

During defrosting operation, the three-way switching valve 2 switches the refrigerant gas discharged from the main compressor 1 to the condenser 3.
is mixed with the high-pressure liquid of
Defrost the evaporator. The liquid refrigerant generated by this defrosting is depressurized by the suction pressure regulating valve 12 through the first on-off valve 11 due to the second on-off valve 9 being blocked, and then the pressure is reduced in the second heat exchanger 10.
The refrigerant gas exchanges heat with the high-temperature, high-pressure discharged refrigerant gas of the auxiliary refrigerant circuit, is vaporized, and is returned to the main compressor 1, thereby preventing the liquid from returning into the compressor and preventing liquid compression.

FIG. 2 shows another embodiment of the present invention, in which the three-way switching valve 2 in the main refrigerant circuit is connected to the condenser 3.
It is provided on the outlet side of the main compressor 1, and is configured to use only the discharged gas of the main compressor 1 without using the high pressure liquid of the condenser during defrosting operation.

As described above, this project consists of a main refrigerant circuit that returns from the main compressor to the main compressor via a three-way switching valve, a condenser, a first heat exchanger, an expansion valve, an evaporator, and an on-off valve, and a second heat refrigerant circuit that returns from the auxiliary compressor to the main compressor. an auxiliary refrigerant circuit that returns to the auxiliary compressor via an exchanger, an auxiliary condenser, a second expansion valve, and the first heat exchanger; and a auxiliary refrigerant circuit that branches from the main compressor through a three-way switching valve to the first heat exchanger; a defrosting refrigerant circuit that reaches the evaporator via an on-off valve, vaporizes the liquid refrigerant produced by defrosting the evaporator, and returns to the main compressor after being bypassed by the second heat exchanger of the auxiliary refrigerant circuit; Since the liquid refrigerant in the main refrigerant circuit generated by defrosting the evaporator is reduced in pressure by the suction pressure regulating valve, the high temperature and high pressure discharge refrigerant gas in the sub refrigerant circuit is transferred to the second heat exchanger. Since it exchanges heat with the liquid and returns to the main compressor after being vaporized, it is possible to prevent the liquid from returning into the main compressor and prevent liquid compression.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram showing one embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram showing another embodiment of the present invention. 1... Main compressor, 2... Three-way switching valve, 3... Condenser, 5... First heat exchanger, 6... Expansion valve, 7,
9, 11... Opening/closing valve, 8... Evaporator, 10... Second heat exchanger, 12... Suction pressure regulating valve, 13...
Subcompressor, 14...Auxiliary condenser, 15...Second expansion valve.

Claims (1)

[Scope of utility model registration request] The main refrigerant circuit returns from the main compressor to the main compressor via the three-way switching valve, condenser, first heat exchanger, expansion valve, evaporator, and on-off valve, and the sub-compressor returns to the second heat exchanger and auxiliary condensing. an auxiliary refrigerant circuit that returns to the auxiliary compressor via the refrigerant, the second expansion valve, and the first heat exchanger; a defrosting refrigerant circuit that reaches the evaporator, vaporizes the liquid refrigerant produced by defrosting the evaporator, bypasses the second heat exchanger of the auxiliary refrigerant circuit, and then returns to the main compressor. A defrosting device for a refrigeration cycle characterized by: