Experiment verified simulation study of the operating sequences on the performance of adsorption cooling system

Abstract

In this study, simulation was conducted to investigate the effect of heat recovery, mass recovery, pre-heating and pre-cooling processes and their combinations on the system performance of a double-bed adsorption cooling system. The model developed consists of pressure variations and detailed compressible flow with flow resistance, which other similar studies had not taken into consideration, thus a detailed simulation of mass recovery, and pre-heating and pre-cooling processes is included in this study. A double-bed adsorption cooling system with silica gel and water as adsorbent-adsorbate pair was built for verifying the simulation models. Based on the simulation results, it was found that the basic cycle provided a COP and SCP of 0.20 and 57.6 W/kg, respectively. By conducting heat recovery for 30 seconds, the COP was increased by 20% to 0.24 compared to the basic cycle. The SCP was also increased to 66.4 W/kg, a 15% increase. The major advantage through conducting the mass recovery is in the SCP, whereby it was increased by 40% to 80.8W/kg. Additionally, performing only the pre-heating and pre-cooling process can also bring some benefits to the system. Therefore, for adsorption cooling systems that cannot carry out the mass recovery and/or heat recovery cycles, performing pre-heating and pre-cooling process only is recommended. This not only can reduce the cost, but also simplify the control program of the systems. Moreover, mass recovery followed by pre-heating and pre-cooling cycle is highly preferred when the SCP is the optimization target, since the SCP was hugely increased by 41% to 81.4 W/kg.