Ejection and throttling double-temperature-zone CO2 refrigeration system and application thereof

Abstract

The invention discloses an ejection and throttling double-temperature-zone CO2 refrigeration system and application thereof. An outlet of a low-temperature stage CO2 ejector sequentially communicateswith a low-temperature stage supercooler, a CO2 low-pressure stage compressor, a CO2 high-pressure stage compressor, a CO2 gas cooler, a medium-temperature stage supercooler, and a main stream inlet of the low-temperature stage CO2 ejector. An outlet of a medium-temperature stage CO2 ejector sequentially communicates with the medium-temperature stage supercooler, a high-pressure stage CO2 compressor, the CO2 gas cooler, and a main stream inlet of a CO2 medium-temperature ejector. According to the ejection and throttling double-temperature-zone CO2 refrigeration system, the gas sucking pressureof the compressor can be improved, the compression ratio of the compressor is decreased, the temperature of a CO2 fluid before throttling is decreased, the throttling loss is reduced, the refrigeration amount can be increased, and the system efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of refrigeration, heating and heat pump, and in particular relates to a CO 2 Refrigeration systems and applications. Background technique [0002] In today's society, the application of refrigeration has penetrated into almost every aspect of human life, and has made outstanding contributions to improving the quality of human life. Due to the increasingly serious problems of energy shortage and environmental pollution, in order to achieve a low-carbon economy, refrigerants with low greenhouse effect are being developed and applied. CO 2 As a natural working fluid, it has become an important option for a new generation of refrigerants. CO 2 ODP=0, GWP=1, security level A1, CO 2 Become an important substitute for CFC and HCFC substances. And CO 2 The cooling capacity of R22 is 5 times larger; the pressure ratio of the compressor is small; the heat transfer performance is good; the relative pressure loss ...

AI Technical Summary

Problems solved by technology

[0004] Generally, mechanical subcooling can be used to achieve supercooling, that is, using a separate auxiliary refrigeration cycle to subcool the refrigerant in the main refrigeration cycle, but this method will introduce other refrigerants into the system as the working fluid of the auxiliary refrigeration cycle, and the system will Environmental protection is poor, increasing the cost of the system

[0005] The refrigeration system used in supermarkets requires two temperature zones, freezing and refrigeration, and the system performance is poor when the ambient temperature is high

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