Performance study of adsorption refrigeration system with composite adsorbent

Abstract

As an effective way to improve the performance of heat and mass transfer, Composite adsorbent used in adsorption refrigeration has attracted increasing research attention. The aim of the research is to reveal composite theory of silica gel composite adsorbent and to understand adsorption refrigeration system mechanism running by above composite adsorbent. Coarse porous silica gel with different particle diameters was selected as the matrix of composite adsorbent and calcium chloride was selected as additive. The results showed that composite adsorbent's thermal conductivity and adsorption capacity increased significantly compared with pure silica gel. The thermal conductivity could be increased by 58.2%, and the adsorption capacity could be increased by 4–10 times. Finally, the adsorption refrigeration system using silica gel-calcium chloride composite adsorbent was studied. A two-bed adsorption refrigeration cycle running by above composite adsorbent was adopted. The experimental results showed that the optimal values of system cooling capacity and COP were not at the same time. The system cooling capacity reached its maximum at 1500 s and the system COP reached its maximum at 1200 s. The best heat recovery time was 20 s. The SCP of the system was up to 288.1 W kg−1, which could reduce the volume of the adsorption refrigeration system effectively.