Energy-saving middle temperature refrigerant/middle temperature refrigerant cascade refrigeration system

Abstract

The invention discloses an energy-saving middle temperature refrigerant / middle temperature refrigerant cascade refrigeration system, which comprises a high-temperature level refrigeration cycle and a low-temperature level refrigeration cycle, wherein heat exchange is carried out by virtue of a condensation evaporator. The high-temperature level refrigeration cycle is additionally provided with a high-temperature level refrigeration branch. The high-temperature level refrigeration cycle and the low-temperature level refrigeration cycle adopt the same middle temperature refrigerant, and share the same evaporator, and switching is realized through the opening and closing of an electromagnetic valve. The cascade refrigeration system disclosed by the invention has the remarkable effects that the refrigeration coefficient is high, cold supply can be realized respectively under the high-temperature level working condition and the low-temperature level working condition, energy can be saved, the operating cost can be lowered, and the use ratio of equipment can be improved.

Description

technical field [0001] The invention relates to the field of environmental simulation test equipment and cold storage refrigeration, in particular to an energy-saving intermediate-temperature refrigerant / intermediate-temperature refrigerant cascade refrigeration system in full-temperature working conditions above -60°C. Background technique [0002] In the vapor compression refrigeration cycle, due to the limitation of the compression ratio of the refrigeration cycle and the thermophysical properties of the refrigerant, the commonly used single-stage compression refrigeration cycle can only obtain a low temperature of -20--40°C. For low temperature, a two-stage compression refrigeration cycle with a medium temperature refrigerant is often used. When a low temperature below -50°C is required, a refrigeration cycle in which a medium temperature refrigerant and a low temperature refrigerant are cascaded is used; the research results of many scholars show that at -40-- In the te...

AI Technical Summary

Problems solved by technology

The two-stage compression refrigeration system and the cascade refrigeration system need to start the two-stage compressor all the time to meet the cooling requirements, and the redundant refrigeration needs to provide heating power to balance, which causes a large waste of energy

At present, the cascade refrigeration system can cool the high-temperature stage and the low-temperature stage separately by means of double evaporators, but this will lead to the problem of increasing equipment investment costs and increasing the number of automatic control points; in addition, the cascade refrigeration system uses low-temperature refrigerants. At room temperature, all of them will be vaporized into superheated steam, which will bring safety hazards to the entire refrigeration system

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