Absorption-compression composite refrigeration system and method based on forward and reverse cycle coupling

Abstract

The invention discloses an absorption-compression composite refrigeration system and method based on forward and reverse cycle coupling. The system includes a power sub-cycle and an absorption-compression composite refrigeration sub-cycle. The system and method use the higher temperature part of the medium and low temperature heat source to drive the power sub-cycle to do work, reducing the heat source directly used for the heat exchange temperature difference of the absorption-compression compound refrigeration system; the lower temperature part and the power sub-cycle exhaust heat as the absorption-compression The heat source of the compound refrigeration sub-cycle; the work done by the power sub-cycle drives the compressor in the absorption-compression compound refrigeration sub-cycle. In the absorption-compression composite refrigeration sub-cycle, the compressor is located between the evaporator and the absorber, and the evaporation pressure can be lower than the absorption pressure, so that the evaporation temperature can be lowered, which meets the needs of the low-temperature refrigeration field, and at the same time enables the system to operate Normal operation under higher condensing temperature conditions. The input energy of the whole system is medium and low temperature heat source, and the product output is low temperature cooling capacity, which does not require external input work.

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 composite refrigeration system and method based on forward and reverse cycle coupling. Background technique [0002] 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. It has a wide range of refrigeration temperatures, about -60°C to 10°C, and is widely used in air conditioning, cold storage, and petroleum smelting and other chemical processes. The evaporation temperature of conventional single-stage absorption refrigeration cannot be too low, and it is only suitable for some industrial sectors such as air conditioning and cold storage. But there are also some industrial sectors, such as the food processing industry (quick-freezing, freeze-drying, long-term ...

AI Technical Summary

Problems solved by technology

The evaporation temperature of conventional single-stage absorption refrigeration cannot be too low, and it is only suitable for some industrial sectors such as air conditioning and cold storage

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 ice) production, etc., need to use low-temperature cooling capacity (such as lower than -30°C), at this time, single-stage absorption refrigeration is difficult to meet the requirements, and multi-stage processes are required

Although the two-stage absorption refrigeration cycle proposed by Rogdakis and Antonopoulos can produce cooling capacity from -70°C to -30°C, the thermal performance coefficient is low

In addition, when medium and low temperature heat energy (such as flue gas at 350°C) is used to directly drive the absorption refrigeration cycle, there will be a large temperature difference between the heat source and the working medium, resulting in large irreversible losses.

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

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