Simulation Of Working Process And Study On Performance For Solar Absorption-subcooled Compression Hybrid Cooling System

Solar subcooled absorption-compression hybrid cooling system is a new type of efficient and economical solar refrigeration device,and it always meets the demand of cooling load despite of solar radiation and ambient temperature change. The running cost of the hybrid system is less than the traditional solar cooling system because it doesn’t need any auxiliary heat source. It may promote the application of solar refrigeration technology in high-rise buildings.Based on the measured meteorological data of subtropical city Guangzhou, the paper developed a corresponding parametric model for the hybrid refrigeration system, the performance of hybrid system was analysed under different external conditions. the working process of this hybrid system was simulated as well. And a preliminary experimental study was made on the absorption subsystem.Structure parameters have significant impact on the design and the performance of the hybrid system. Under the condition of specific meteorological datas,if the structure parameters are not properly designed, it may leads to the hybrid system to frequent start-stop or crystallization.The influence on the performance and the working process of the hybrid system of three major structure parameters—the collector area, volume of hot water tank and refrigerating capacity of absorption subsystem was discussed respectively,and the corresponding temperature curve were gotten. The results showed that : when the collector area exceed 168m2 or the refrigerating capacity of absorption subsystem less than 13 kW, the temperature of generator will be very high and the hybrid system will risk of crystallization. However,when the collector area less than 105m2 or the refrigerating capacity of absorption subsystem exceed 23 kW, the performance of hybrid system dropped significantly due to the dramatically reduced of the working time of absorption subsystem.Because of the higher evaporation temperature in absorption subsystem,and lower temperature of refrigerant into the evaporator,the performance of the hybrid system is usually better than the traditional one. But the performance of the hybrid system is affected by the coupling working characteristic of absorption and compression subsystems,it changes quite complicated for different working conditions.So the performance of the hybrid system under different working conditions(different evaporation temperature, condensation temperature, absorption temperature) were analyzed as well.Moreover, a small solar double-effect lithium bromide absorption cooling system experimental platform was developed for further experimental study.the result of experimental study showed that: the lithium bromide absorption refrigeration system using evaporative cooling way can work effectively in subtropical city of Guangzhou in summer. The total refrigerating capacity is 8.2kW, the lowest temperature of chilled water is 16 ℃ and the average COP the absorption cooling system is 0.51.