Thermodynamic evaluation of two-stage refrigeration cycle with deep intercooling and series-parallel integration of thermal and mechanical compression

Abstract

ABSTRACT A novel two-stage refrigeration cycle with deep intercooling and series-parallel integration of thermal and mechanical compression is proposed. Its mechanical energy consumption can be reduced by supplementing it with low-grade non-large-scale heat sources. Firstly, to show the advantages of the proposed cycle, the comparison with a two-stage refrigeration cycle with series integration of thermal and mechanical compression as well as the cascade system driven by heat and power is implemented. Secondly, the effects of the major operating parameters affecting the performance such as inter-stage pressure, inlet quality of high-pressure stage mechanical compressor and thermal compressor flow rate are analyzed. Finally, the near-optimal operating parameters for different working conditions are proposed. It is exhibited that the ECOP of the proposed layout increases by 19.4–43.7% as compared to the traditional system layouts. It is recommended that the inlet quality of 0.9 in the high-pressure mechanical compressor serves as a good guide for different operational conditions. The results show that the proposed system has a clear potential of lowering the energy consumption of cold storage refrigeration systems by supplementing with available low-grade heat. It is believed that the proposed cycle promotes a more sustainable development of fresh produce e-commerce logistics.