Performance enhancement of some alternatives to R-502

Abstract

The results of an experimental study on the behaviour of some new alternatives to R-502 using heated suction accumulator are presented. The experimental set up was composed of a fully instrumented air-source heat pump with a capacity of 12000 BTUH and equipped with a heated suction accumulator. The refrigerant temperatures were varied at the evaporator entrance to simulate various extreme conditions encountered in air-source heat pump applications. The primary parameters observed during the course of this study were mass flux, heat flux, quality evaporator and condenser thermal capacities, power consumed and pressure ratios for the azeotropic refrigerant mixtures under investigation. The test results showed that a heated suction accumulator enhanced the evaporation of more volatile component of ternary azeotropic refrigerant mixtures. Thus, increasing the mixture thermal capacity as well as the COP. Furthermore, experiments have also shown capacity increases of 27 per cent with a heat accumulator over an unheated accumulator at - 15°C outside air temperatures.