Novel energy-saving refrigerating unit and working method thereof

Abstract

The invention discloses a novel energy-saving refrigerating unit and a working method thereof. In the novel energy-saving refrigerating unit, liquid from a condenser enters a liquid receiver; the high-pressure liquid coming out of the liquid receiver is divided into two paths by a heat exchanger; one path of the liquid is throttled by an expansion valve and enters the low-pressure end of the heat exchanger to be evaporated; the other path of the liquid enters a low-temperature evaporator through the low-temperature expansion valve, and a refrigerant gas returns to a gas-liquid separator of the unit and enters a low-temperature compressor to be compressed; the gas evaporated by the heat exchanger enters a moderate-temperature gas-liquid separator and a moderate-temperature compressor to be compressed; the exhaust gas of the moderate-temperature compressor is mixed with the exhaust gas of the low-temperature compressor by a check valve, and the mixed exhaust gas enters an oil separator and then flows into the condenser and returns to the liquid receiver; the refrigerant oil separated by the oil separator enters an oil receiver; and when the moderate-temperature compressor is short of oil, the refrigerant oil in the oil content stops entering the oil receiver and starts to enter the moderate-temperature compressor. The novel energy-saving refrigerating unit fulfills the purpose of saving energy for the unit by using the cold energy of the highly efficient moderate-temperature compressor in the unit.

Description

technical field [0001] The invention relates to a novel energy-saving refrigeration unit and a control method thereof. Background technique [0002] When the evaporator is far away from the low-temperature unit or at a high position, in order to reduce the cooling capacity reduction caused by resistance in the tube and gravity, increasing the subcooling degree of the refrigerant is a common and effective way. There are three common ways for the unit to achieve liquid supercooling: 1. The liquid from the liquid receiver passes through the subcooling section set at the lower part of the condenser, and uses air to provide supercooling for the refrigerant liquid; 2. Use part of the liquid in the unit itself Provides subcooling for another part of the liquid ( figure 1 ) The outlet liquid of the liquid receiver is divided into two paths, one of which passes through the expansion valve to cool the other path of liquid, the supercooled liquid enters the cold end and then evaporate...

AI Technical Summary

Problems solved by technology

The first method is mostly used in small units where the unit is relatively close to the condenser, but the increase in the degree of subcooling is limited; although the second method can increase the degree of subcooling of the liquid, due to the consumption of a part of the liquid refrigerant, the reach The total amount of liquid in the evaporator is reduced, and the energy-saving effect is not obvious; although the realization of the third method has a good energy-saving effect, it requires an additional refrigeration unit, which will inevitably increase the cost of the unit

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