Conference Year
2018
Keywords
sorption, chemisorption, heat pump, efficiency
Abstract
Sorption heat pumps utilize the thermal effect of the sorbent bonding with the refrigerant (sorbate) through a variety of physio-chemical processes, and when such bonding is due to chemical reaction between solid sorbent and gas refrigerant, the system is known as chemisorption heat pump. The most commonly used refrigerant in chemisorption systems is ammonia, and it can work with a variety of sorbent materials across a wide temperature range. The abundance in working pair selection and the viability of resorption configuration leads to multiple available cycle configurations and working pairs for heat pump system design. Therefore, preliminary evaluation of these available configurations and working pairs is necessary to analyze system performance, identify key aspects for optimization, and identify the optimal combination of cycle configuration and working pair for a particular application. In this study, the efficiencies of several chemisorption heat pump cycles are analyzed and compared using a generalized analytical model. The effects on system performance were compared between different working pairs, dead thermal mass factors, and system operating conditions. The effect of heat and mass recovery on system performance was also investigated for each cycle configuration using the model. Based on the comparisons, the optimal single-effect cycle configuration and working pair was identified for several applications.