Comparative performance analysis of a two-bed adsorption cooling system with adsorption of different adsorbates on silica-gel

Abstract

This study presents a comparative performance analysis of a two-bed adsorption cooling system in which various working fluids are used with silica-gel as adsorbent pairs. An adsorption cycle simulation program has been developed to investigate the influence of different operating conditions on the cooling power and COP of the system. For the configuration of the adsorption cycle in the present simulation, two adsorption bed design is used. Different working fluids as adsorbate are considered in this study. These are water, methanol, R134a and R404a. They can be employed in the adsorption refrigeration systems driven by heat sources such as solar energy or waste heat with a temperature lower than 100C. It is observed that the parameters that have the most significant effect on COP and SCP are, in decreasing order, the adsorption heat of adsorbate-adsorbent pair, cooling source temperature, heating source temperature, condensation temperature at the condenser and evaporation temperature at the evaporator. These results are valid for all working pairs. In general, increasing evaporation temperature and decreasing adsorption bed temperature during the adsorption process increases COP and SCP for all working pairs. In addition to that different design parameter such as specific cooling power, the mass of adsorbent and adsorbate etc. are calculated, compared and discussed for each working pairs.