Study of a two stage air-cooled ammonia-water absorption refrigeration cycle for solar cooling system

抄録

Combined solar hot water driven with air-cooled equipments could be realized by two-stage ammonia-water absorption refrigeration systems for small scale residential uses. In this paper, both thermal and electrical performances are evaluated by system mathematical models. The analysis showed that cooling air should cool condenser firstly and absorber secondly to reach an optimum performance. Thermal COP about 0.34 and electric COP above 25 could be obtained in hot summer working condition. The researches show that both thermal and electrical COP increase with the increase of driven hot water and evaporation temperature, and with the decrease of cooling air temperature. Rectifier is not required in the system because the basic concentration of ammonia vapour has already reached the purity standard. Low-grade solar energy could be utilized efficiently due to large inlet and outlet temperature difference of the driven hot water. Absorption heat recovery of low pressure cycle could be realized to increase thermal COP for ceiling radiation cooling conditions.