An efficient and compact integrated microchannel membrane-based absorption refrigeration system

Abstract

Microchannel membrane-based absorption refrigeration system (MMARS) is an efficient and compact solution for delivering cooling capacity, driven by renewable and waste thermal energy. This study introduces a novel integrated MMARS (I-MMARS), featuring integrated evaporator-absorber and desorber-condenser, to further enhance the system compactness. By analyzing the influence of the gap distance within these two integrations on the system efficiency (COP) and compactness (volumetric cooling capacity, Rqv), the advantages of the new system are highlighted. The highest Rqv (136.765 kW/m3) and corresponding COP of 0.6994 are found to be achieved with a 0-mm gap in the evaporator-absorber integration and a 0.2778-mm gap in the desorber-condenser integration. The performance of the I-MMARS, with these optimal gap distances, is further examined under various operating conditions. Our findings indicate that the system COP can be enhanced by increasing both the heat source temperature and the chilled water temperature. Simultaneously, reducing the heat source and solution flow rates, or the cooling water temperature also contributes to COP improvements. Finally, a comparison with conventional MMARS shows that the novel I-MMARS can boost system compactness by 37.88 %. The innovative I-MMARS paves the way for the development of small-scale absorption refrigeration systems in a highly efficient and space-saving manner.