Parametric study of absorption-compression hybrid refrigeration cycle with multi-stage heat recovery

Abstract

Traditional absorption-compression hybrid refrigeration cycles, e.g., two-stage and cascade cycles, can reduce the electricity consumption of chillers in low-temperature scenarios such as cold storage. However, their heat consumption cannot be fully covered by the heat supply of small- and moderate-scale heat sources, which adversely affects the operational reliability and hinders the actual applications. In this regard, an absorption-compression hybrid refrigeration cycle with multi-stage heat recovery is proposed to effectively address this issue. In this study, the thermodynamic analysis of the proposed cycle was performed. Performance comparisons with traditional systems are conducted to demonstrate the advantages of the proposed system. Then, the effects of inter-stage pressure were analyzed in detail. Finally, trends in the optimal inter-stage pressure for different conditions were fitted and obtained using artificial neural networks. A case study showed that the internal heat recovery enhanced the exergy efficiency and heat power coefficient of performance by 26.9% and 109.7%, respectively. The novelty of this study lies in the proposal of a novel absorption-compression hybrid refrigeration cycle to reduce the heat consumption per unit production of cooling capacity, and to obtain the design criteria for inter-stage pressure under different conditions. This study achieves energy savings in cold-storage refrigeration systems.