Cascading refrigerating system and method based on forward and reverse cycle coupling

Abstract

The invention discloses a cascading refrigerating system and method based on forward and reverse cycle coupling. The system comprises power subcycle, absorption type refrigeration subcycle and compression type refrigeration subcycle. A low-temperature heat source is adopted in the system to drive the power subcycle to act, heat exhausted by the power subcycle drives the absorption type refrigeration subcycle to carry out refrigeration, power acted by the power subcycle drives the compression type refrigeration subcycle to carry out refrigeration, and the absorption type refrigeration subcycle and the compression type refrigeration subcycle form the cascading refrigerating system. The absorption type refrigeration subcycle works in a high-temperature area, and the compression type refrigeration subcycle works in a low-temperature area. Cooling loads are provided for the condensation process of the compression type refrigeration subcycle of the low-temperature area by the evaporating refrigeration process of the absorption type refrigeration subcycle of the high-temperature area, and the absorption type refrigeration subcycle and the compression type refrigeration subcycle are combined through an evaporation-condensation device. The input energy of the system is a medium and low temperature heat source, and low temperature cooling capacity is product output.

Description

technical field [0001] The invention relates to the technical field of medium and low temperature heat source refrigeration, in particular to an absorption-compression cascade refrigeration system and method based on forward and reverse cycle coupling. Background technique [0002] Ammonia water absorption refrigeration technology is a refrigeration technology that can be driven by low-temperature waste heat resources or low-temperature renewable energy such as solar energy and geothermal energy. Smelting and other chemical processes. The evaporation temperature of single-stage ammonia water absorption refrigeration should not be too low, and is suitable for air conditioning, cold storage and some industrial sectors. But there are also some industrial sectors, such as the food processing industry (quick-freezing, freeze-drying, long-term preservation of food, etc.), some gas (propane, etc.) liquefaction, some low-temperature environmental laboratories, and solid CO 2 (Dry ...

AI Technical Summary

Problems solved by technology

But there are also some industrial sectors, such as the food processing industry (quick-freezing, freeze-drying, long-term preservation of food, etc.), some gas (propane, etc.) liquefaction, some low-temperature environmental laboratories, and solid CO 2 The production of (dry ice) requires the use of cooling capacity with a lower temperature (such as lower than -30°C). At this time, the single-stage ammonia water absorption refrigeration is difficult to meet the requirements, and a two-stage process is required.

Compared with the single-stage cycle, the thermal coefficient of the two-stage cycle is lower, and the system is complex, there are more equipment, the metal consumption is larger, and the operation is also more complicated.

For the low-temperature cooling capacity, it can also be obtained by cascade compression refrigeration cycle in industry, but the compression refrigeration cycle is used in the high-temperature and low-temperature regions of the cycle, which will consume a lot of work.

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