Performance of combined solar energy and waste heat driving absorption subcooled CO2 refrigeration-desalination cogeneration system
Aiming at meeting the requirement of cooling and freshwater on the basis of improving the energy efficiency of the CO2 refrigeration system,a combined solar energy and waste heat driving absorption subcooled CO2 refrigeration-desalination cogeneration system(Abs-CWCS)is proposed.The thermodynamic model is developed,and the coefficient of performance(COP)of the system is analyzed considering the influence of ambient temperature and solar radiation.In addition,to further assess the impact of climatic conditions,5 typical cities are selected to evaluate the annual performance factor(APF)and annual freshwater production.The results indicate that both COP and daily freshwater production of the Abs-CWCS are increased.Compared with the baseline CO2 refrigeration-desalination cogeneration system(Base-CWCS),COP is increased by 1.95%~41.02%.Moreover,the freshwater production is increased by 0.8~28.6 times,and the discharge pressure of the Abs-CWCS can be reduced by 7.86%.The annual performance factor(APF)can be effectively improved as the Abs-CWCS of the solar absorption subcooled system is adopted.Additionally,an average APF enhancement ratio of 3.66%achieve in five typical cities,and the annual increase rate of freshwater production can reach up to 9.54%~64.62%.Therefore,the new proposed Abs-CWCS is a feasible solution for the simultaneous demand of refrigeration and freshwater.
absorption subcoolingCO2 refrigeration systemsolar energyrefrigeration and freshwater cogenerationwaste heat