Unsteady analysis for solar-powered hybrid storage LiBr-water absorption air-conditioning

Hybrid (cold plus refrigerant) storage design for continuous (24-h a day) solar-powered LiBr-water absorption air-conditioning systems has many advantages. It can improve system performance, reduce collector size, lower storage tank capacity making the system more attractive. This paper analyzes the impact of unsteady solar conditions on operation parameters and system performance of a hybrid storage LiBr-water absorption air-conditioning chiller of 5 kW cooling power during a few representative days in summer and winter in Dhahran City, Saudi Arabia. The system consists of flat-plate collector and absorption chiller with hybrid storage tanks (cold and refrigerant) in addition to an excess heat storage tank that might be needed to prevent crystallization. The results indicate that, under constant cooling load constraint, the coefficient of performance is better in winter; however, the required collector area and refrigerant storage tank size are smaller in summer.