Heat Recovery for Adsorption Refrigeration System via Pinch Technology

An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission. However, one of the weaknesses is its low efficiency and more importantly its high cost. The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP). Analysis based on pinch technology can be helpful to optimal heat recovery operation. In this paper, temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology. The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds. Dynamic characteristic(time factor) of adsorption refrigeration system is the main resistance for heat recovery. The effect of pinch point temperature difference on the system COP is not distinct. Furthermore, when the driving temperature is 90°C, the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system. Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed, four-bed, mass recovery, et al.).