Performance Comparison of Single-Stage and Cascade Refrigeration Systems Using R134a as the Working Fluid

Authors : Murat HOŞÖZ

Pages : 285-296

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :This study presents an experimental comparison of single-stage and cascade vapour-compression refrigeration systems using R134a as the refrigerant. The experimental plants employ a vapour-compression refrigeration cycle serving as a base unit, a cooling tower and another vapour-compression refrigeration cycle serving as a higher-temperature unit in the cascade operation. In the single-stage operation the condenser of the base unit was connected to the cooling tower, whereas in the cascade operation it was thermally coupled to the evaporator of the higher-temperature unit via a water stream. Using data obtained from steady-state test runs, the performance characteristics of both systems, namely evaporating and condensing temperatures, refrigerant mass flow rate, compressor power, coefficient of performance insert ignore into journalissuearticles values(COP);, compressor discharge temperature, compressor volumetric efficiency and the ratio of compressor discharge to suction pressures, were evaluated. The results show that, for a given refrigeration capacity, the cascade system provides a lower evaporating temperature, lower compressor discharge temperature, lower ratio of discharge to suction pressures and higher compressor volumetric efficiency at the expense of a lower COP.
Keywords : Refrigeration, Cascade system, Single stage system, Coefficient of performance, R134a