Energy and exergy analysis of a novel ejector-assisted compression–absorption–resorption refrigeration system

Abstract

We propose two novel configurations of an ejector-assisted compression–absorption–resorption refrigeration system. In these configurations, an absorption–resorption sub-cycle is cascaded to a compression sub-cycle to deliver two simultaneous refrigerating effects to the end-users. The absorption–resorption sub-cycle utilises waste heat and delivers the refrigerating effect at -5°C, while the compression sub-cycle delivers the refrigerating effect at 7°C. The two novel configurations are categorised as the first configuration (C1) and the second configuration (C2), based on the cascading of the compression sub-cycle. The first and second law coefficients of performance (COP) of the proposed configurations are computed and compared at different compression ratios, generator and absorber temperatures, and ejector pressure ratios. The results indicate that the configuration C2 achieves the highest COP of 0.98 at 25°C absorber temperature and the COP changes from 0.98 to 0.79 as the absorber temperature increases from 25°C to 55°C. For the same refrigerating capacity, the proposed configurations C1 and C2 save electricity consumption by 36 % and 23 %, respectively, as compared with the electricity consumption by the conventional compression refrigeration system. The performance of the cascaded compression sub-cycle using R717, R600, and R290 refrigerants is assessed and compared with the widely used R134a and R410A refrigerants.