Comprehensive performance analysis of cascade refrigeration system with two-stage compression for industrial refrigeration

The cascade refrigeration system with two-stage compression (CRST) with R1150/R717 as the refrigerant group was studied to replace the three-stage cascade refrigeration system (TCRS) with R1150/R41/R717 as the refrigerant group, aiming to improve the operational efficiency of the industrial refrigeration system in the temperature range of-120 degrees C to-80 degrees C. This paper selected typical cities in five major climatic zones in China to analyze the coefficient of performance (COP), annual total power consumption, and seasonal energy efficiency ratio (SEER) of CRST and TCRS under different climatic conditions based on compressor discharge temperature, compressor input power, COP, and thermodynamic perfectibility. According to the results, the compressor input power of CRST is 1.45-1.61 kW lower than that of TCRS. CRST improved by 7.0%-11.7% in terms of COP and thermodynamic perfectibility. The seasonal performance analysis compared the CRST and TCRS operating in five different climate zones; the SEER of CRST increased by 26.3%- 29.2%. CRST has a significant energy-saving effect, with an annual total power consumption of 8.6%-10.2% lower than that of TCRS. Finally, in the evaporation temperature range of-120 degrees C to-80 degrees C, the technical scheme of using CRST to replace TCRS in different climate zones is entirely feasible.