Performance analysis of adsorption refrigeration using a composite adsorbent with improved heat and mass transfer

Abstract

Adsorption refrigeration is a typical environmental protection and energy-saving waste heat utilization refrigeration technology. However, improving the heat and mass transfer performance of adsorption beds is crucial to the wide-spread applications of adsorption refrigeration systems. In this paper, three types of composite adsorbents are proposed: adsorbents with improved heat transfer, improved mass transfer, and simultaneously improved heat and mass transfer. Both characteristics of adsorption and heat transfer are tested and compared. Based on the experimental results, the use of these three types of composite adsorbents in the adsorption refrigeration system is further examined. The results indicate that the silica gel (SG)/MIL-100/CF (SGMC) composite outputs the highest cooling capacity and exhibits a coefficient of performance (COP) comparable to that of a composite adsorbent with improved mass transfer. The cooling capacity and COP of the proposed SGMC system compared with those of the traditional SG–water system increase by 22% and 12.8%, respectively, and the refrigeration cycle time is shortened by 16.7%. Based on the optimal SGMC system, the impact of operation parameters is further investigated, and optimum parameters are selected to enhance the overall system performance.