Experimental study on a solar-powered thermochemical sorption refrigeration system using strontium chloride/EG-ammonia working pair

摘要

An intermittent thermochemical sorption refrigeration system consisted of a reactor and an evaporator/condenser was constructed and studied by using strontium chloride/EG (expanded graphite) as composite sorbent and ammonia as refrigerant. Firstly, the sorption characteristic of strontium chloride/EG-ammonia was investigated, and the reaction enthalpy and entropy were obtained experimentally and compared with other previous data. Then, from the view of practical application, the specific cooling power (SCP) and coefficient of performance (COP) of the system were obtained at different operating temperatures. The regeneration process of SrCl_2 was driven by high-temperature heat transfer fluid with temperature of 94±1.5°C from an external heat source, which was used to simulate solar collectors. In the evaporation-adsorption process, the evaporation temperature varied from 15 to -15°C, and heat sink temperature was kept at 25±0.5°C. The experimental results showed that the COP increases with increasing evaporation temperature, and its maximum value could reach 0.24 when the evaporation temperature was 15°C, and the corresponding mean SCP was 291.5W/kg.