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.

During the past few decades, the growing demand for air conditioning has caused a significant increase in demand for primary energy resources. Adsorption cooling system is one of the technologies which could be powered by renewable energy. This study aims to improve the performance of a solar-powered adsorption chiller by applying a novel composite adsorbent, a mixture of activated carbon, silica gel and calcium chloride. Modeling is established to investigate the cooling performance of a composite adsorbent based adsorption chiller driven by flat-type solar collectors with three different configurations of glaze: (1) single glazed cover; (2) double glazed cover and (3) transparent insulation material (TIM) cover. The simulation results show that the coefficient of performance (COP) and the specific cooling power (SCP) of the adsorption chiller depend hugely on the solar collector temperature. It is found that a double glazed cover shows the best cooling performance and 30 m² is the most optimized solar collector area. Two to three hours of pre-heating time is required to initiate the desorption process of the adsorber in a day of operation. This newly developed silica activated carbon/CaCl₂ composite material as adsorbent used in the adsorption chiller could achieve a high mean COP_sc of 0.48. Its satisfactory performance suggests that this novel composite material has a potential to be used in the adsorption chiller system even if it is powered by unstable solar energy.