JPS5912526Y2 - Refrigeration equipment - Google Patents

Description

[Detailed explanation of the idea] This proposal concerns improvement of refrigeration equipment G÷.

．．・Conventionally, when defrosting a refrigerator/freezer equipped with multiple evaporators connected in parallel, each evaporator is hot gas defrosted in sequence, and each evaporator is The liquid refrigerant stored in the evaporator is transferred to each evaporator on the inlet side of the compressor through a bypass solenoid valve having a pressure reducing effect, which is provided in parallel with the suction pipe solenoid valve. This method prevents a sudden liquid back-up during recooling operation, but there is a problem in that it requires as many bypass solenoid valves as there are evaporators, and the control circuit becomes complicated.

This proposal has been made in view of the above points, and will be explained below based on the embodiments shown in the figures.

1 is a compressor, 2 is a condenser, 3 is a solenoid valve, 4 is a pressure reducing valve installed in parallel with the solenoid valve 3, 5 is a liquid header, 6,
7 is a liquid pipe solenoid valve; 8 and 9 are check valves provided in parallel with the liquid pipe solenoid valves 6 and 7; 10 and 11 are expansion valves; 12.
13 is a check valve provided in parallel with the expansion valves 10 and 11; 14 and 15 are evaporators; 16. 17 is the suction pipe solenoid valve, 18 is the gas header, 19 is the spacer, 20
is a side pipe provided between the compressor 1 and the condenser 2, and from the side pipe to each evaporator 14. 15 and suction pipe solenoid valve 16
．． 17, there are hot gas solenoid valves 21, 22, respectively.
The side branch pipes 23 and 24 provided with the above are connected to form a refrigeration cycle.

Reference numeral 25 denotes a bypass solenoid valve having a pressure reducing effect, which is provided in parallel with each of the suction pipe solenoid valves 16 and 17, and the bypass solenoid valve is connected to each of the evaporators 14 and 14. A check valve 26.15 is provided on the outlet side of the suction pipe solenoid valve 16.17 in parallel. 27
28. Connected to 29.

In a refrigeration system constructed in this way, the hot gas solenoid valves 21 and 22 and the bypass solenoid valve 25 are closed, and the compressor 1 adiabatically compresses the medium, which is then transferred to the condenser 2. The liquid refrigerant is condensed and liquefied, and this liquid refrigerant flows into the liquid header 5 via the electromagnetic valve 3.

The electromagnetic valve 3 is opened during the cooling operation to cause no pressure change, and is closed during the defrosting operation to reduce the pressure of the refrigerant discharged from the compressor 1 to below the hot gas pressure by the pressure reducing valve 4.

The liquid refrigerant divided by the liquid header 5 is depressurized by the expansion valve 10.11 via the liquid pipe solenoid valves 6 and 7, and then sent to the evaporator 14.15.
It is evaporated and cooled.

The gas refrigerant evaporated in the evaporator is passed through the suction pipe electromagnetic valve 16.
17, the gas is collected in the gas header 18 and returned to the compressor 1 via the accumulator 19, and the same operation is repeated thereafter.

When frost adheres to the evaporators 14 and 15 during such normal cooling operation, the solenoid valve 3 is closed during the defrosting operation, and the defrosting side evaporator 1 is closed.
With the hot gas solenoid valve 21 of No. 4 open and the liquid pipe solenoid valve 6 and suction pipe solenoid valve 16 closed, the hot gas discharged by the compressor 1 flows into the branch pipe 23 from the side pipe 20. The hot gas defrosts the evaporator 14 through the solenoid valve 21 and flows into the liquid header 5 through the check valves 12 and 8.

The high-pressure liquid refrigerant discharged from the compressor 1 and flowing out from the condenser 2 is reduced in pressure to a level slightly lower than the hot gas pressure by a pressure reducing valve 4 and flows into a liquid header 5 to prevent it from flowing back into the evaporator 14. Then, the hot gas refrigerant that has been defrosted from the evaporator 14 is mixed with the liquid header 5 and flows into the other evaporator 15 to form a cooling cycle.

After the defrosting of the evaporator 14 is completed, the hot gas solenoid valve 21 is closed and the bypass solenoid valve 25 is opened, and the liquid refrigerant stored in the evaporator 14 passes through the check valve 26 to the bypass solenoid valve 25 which has a pressure reducing effect. The liquid refrigerant is gradually returned to the compressor 1 via the gas header 18, and when there is no more liquid refrigerant in the evaporator 14, the defrosting of the other evaporator 15 is switched to, and the same operation is repeated.

Since the check valves 26 and 27 are connected in reverse to each other, the liquid refrigerant stored in the defrosted evaporator 14.15 is cooled in the evaporator 14.15. This prevents water from flowing into 15.

Also, the evaporator 14. Since l bypass solenoid valves 25 that gradually return the liquid refrigerant stored in the compressor 1 to the compressor 1 are used in common, liquid back-up due to poor liquid refrigerant recovery due to differences in the throttle opening of the bypass solenoid valves is prevented. can.

As described above, the present invention provides a refrigeration system that includes a plurality of evaporators connected in parallel and that performs cooling operation of other evaporators while continuing defrosting operation of one evaporator. This is because piping each equipped with a check valve is connected in parallel to the suction pipe solenoid valve, and one side of the piping is connected to one bypass solenoid valve that has a pressure reducing effect and is connected to the inlet side of the compressor. By combining a bypass solenoid valve with a check valve to gradually return the liquid refrigerant stored in the evaporator to the compressor when recooling operation starts after the defrosting of each evaporator is completed, the liquid return of each evaporator is made common. This has practical beneficial effects such as reducing the number of expensive bypass solenoid valves, simplifying the control circuit, and preventing liquid packs due to poor liquid refrigerant recovery due to differences in the characteristics of the bypass solenoid valves.

[Brief explanation of drawings]

The drawing is a refrigerant circuit diagram showing an embodiment of the refrigeration system of the present invention. 1... Compressor, 14, 15... Evaporator, 16, 17... Suction pipe solenoid valve, 25...
...Bypass solenoid valve, 26, 27...Check valve, 28, 29...Piping.

Claims (1)

[Scope of utility model registration request] In a refrigeration system that is equipped with a plurality of evaporators connected in parallel and that performs cooling operation of other evaporators while continuing defrosting operation of any evaporator, a suction pipe solenoid valve is provided on the outlet side of each of the evaporators. Parallel to
A refrigeration system characterized in that one part of the piping is connected to a pressure-reducing solenoid valve having a pressure reducing effect, which is connected to the dog mouth side of the pressure pipe.