Experimental and theoretical study on a novel double evaporating temperature chiller applied in THICS using R32/R236fa

Abstract A novel chiller with double evaporating temperatures is proposed in this paper, which can be applied in temperature and humidity independent control system (THICS). A zeotropic mixture R32/R236fa is selected as the refrigerant, and chilled water with two different temperatures is produced. The experimental coefficient of performance ( COP exp ), theoretical coefficient of performance ( COP th ), and second law efficiency ( η ) of the chiller are studied. The performance of the chiller is studied by varying the mass fraction of R32 in the R32/R236fa ( W (R32)), chilled water temperature, and the flow rates of the heat transfer media (chilled water and cooling water). The results show that the high temperature chilled water ( T H,out ) can be at 15–18 °C, and the low temperature chilled water ( T L,out ) can be at 6–8 °C. When T H,out is 17 °C and T L,out is 7 °C, the maximum COP th and COP exp are 4.73 and 3.97, respectively. Second law efficiency, η , increases to 31% as W (R32) increases from 0.3 to 0.6.