Optimal temperature of collector for solar double effect LiBr/H_2O absorption cooling system in subtropical city based on a year round meteorological data

摘要

The temperature of collector is one of the important parameters that determine the performance of solar cooling system. The paper mainly deals with the optimal temperature of collector for solar double effect LiBr/H_2O absorption refrigeration system in subtropical city. The study of paper is based on the parametric analysis and does not consider the pressure drop and heat loss of system. The optimal temperature of collector is that maximizes the monthly mean performance of system. Based on the measured year round meteorological data of subtropical Guangzhou, it was found that the optimal temperature of collector is not identical for different months. For the system without the hot fluid storage tank in which the tilted angle of collector is 20° toward to south, evaporation temperature is 5℃, condensation temperature is 43℃, absorber temperature is 40℃ and the energy distribution ratio of generator is 1.5, its optimal inlet temperature of collector from April to October is 100, 100,100,110, 110,110 and 125℃, respectively. The corresponding maximum monthly average total efficiency of system from April to October is 0.241, 0.278, 0.304, 0.407, 0.43, 0.434 and 0.458, respectively. The influence of evaporator temperature, condenser temperature, absorber temperature and the energy distribution ratio, on the optimum temperature of collector was analyzed. The comparison of optimal collector temperature for the system with and without the hot storage tank was also carried out. The paper is helpful to improve the performance of solar double effect LiBr/H_2O absorption cooling system in subtropical city.