Thermodynamic performance comparison of series and parallel two-stage evaporation vapor compression refrigeration cycle

Series and parallel two-stage evaporative strategy for vapor compression refrigeration cycles characterized by temperature and humidity independent control were presented. The theoretical model was established to analyze the performance of parallel two-stage evaporative strategy regarding the coefficient of performance (COP), exergy loss, exergy efficiency in comparisons with series system. And refrigerants R290 and R600 with low global warming potential (GWP) and no ozone depletion potential (ODP) are proposed as alternative refrigerants for R134a in two systems. The results show that compared with R134a, the proposed R600 has better performance with higher specific refrigerating capacity and coefficient of performance, of which specific refrigerating capacity increase 102.72% than that of R134a on average. Series two-stage evaporative strategy for vapor compression refrigeration cycle with R600 had the optimal techno-economic performance, which COP and exergy efficiency are 7.8% and 11% higher than that of parallel two-stage evaporative strategy, respectively.