Optimal Design Of Solar Energy Refrigeration System With Larger Heat Source Temperature Difference

Computer optimization of solar energy refrigeration system can promote the performance of the unit, decrease the heat transfer area of the refrigerator and upgrade the operation coefficient of the system.In this paper, the solar energy refrigeration system with large heat source temperature difference is introduced.A thermodynamic and heat transfer calculation model of this kind of refrigeration cycle is built. According to the tested calculation,the cycle parameters calculation program is correct.Seven parameters are appointed as optimization variables according to the analysis to the system. They are: heat-source temperature difference, evaporator temperature difference, low-pressure absorber temperature difference, high-pressure absorber temperature difference, condenser temperature difference, fluid resistance and medium pressure. Maximum coefficient of performance(COP), minimum heat transfer area and minimum area efficiency ratio are chosen as objective functions.The optimum procedure is programed using FORTRAN language. MPOP method is introduced to optimize the system. The optimized calculation results are perfect. According to the calculation, if maximum coefficient of performance being chosen as objective function, its value can be increased significantly, but heat transfer area is also palpable increased; if minimum heat transfer area being chosen as objective function, heat transfer area is reduced clearly but coefficient of performance is reduced too. When use minimum area efficiency ratio is chosen as object function, the coefficient of performance is promoted clearly but heat transfer area is increased slightly. This result indicates that using minimum area efficiency ratio as objective function can get better results.Compared with original system, optimized system has clearly advantages. In minimum area efficiency ratio optimization solution, coefficient of performance is promoted from 0.584 to 0.698, while heat transfer area is reducede by 2.63641 square meters. Consumption of cooling-water and heat water flux are decreased in the same time.Through the optimizations, the performance of the solar energy refrigeration system with large heat source temperature difference is consummated. The coefficient of performance is increased, the heat transfer area is decreased. This method can be used to optimize the design and the operational parameters of the system.