Energetic and economic analysis of vapour compression refrigeration systems applied in different temperature ranges

To determine the suitable vapour compression refrigeration system for different temperature ranges, this paper established thermodynamic models for a single-stage vapour compression refrigeration system with an economiser (SSRS+E), a two-stage vapour compression refrigeration system (TSRS), and a cascade vapour compression refrigeration system (CRS) and conducted an energetic and economic analysis of it. The results show that compared with TSRS, SSRS+E can save energy by 13.6% and 7.1%, in the evaporating temperatures of -20°C and -25°C, respectively. R744/R717 CRS is superior to TSRS in terms of energy consumption and refrigeration unit investment costs. Compared with TSRS, R744/R717 CRS can save energy by 14.1% and 18.8%, in the evaporating temperatures of -45°C and -50°C, respectively. Based on the energetic and economic analysis, SSRS+E is recommended for use above the evaporating temperature of -25°C. TSRS is recommended for use in the evaporating temperature range of -45°C to -25°C, and R744/R717 CRS is recommended for use below the evaporating temperature of -45°C.