Performance test of residential heat pump after partial optimization using low GWP refrigerants

The present study aimed to improve the performance of the residential heat pump using R-32 and L-41b as a HFO blend after partial optimization by modifying heat exchanger and compressor discharge volume as well as providing the drop-in test data using low GWP refrigerants. Cooling and heating capacities, COP, discharge temperature, pressure drop of evaporator and condenser of the residential heat pump system were measured in case of drop-in test and test after partial optimization. Optimal refrigerant charge for R-32 and L-41b systems was less by 18-25% than that of R-410A system. Capacities of R-32 and L-41b systems through the drop-in test showed 105% and 89-94% of those of R-410A system respectively, while the COP of R-32 and L-41b systems showed 99-101% and 104-105% of those of R-410A systems, respectively. Discharge temperatures of R-32 system showed up to 94.7 degrees C, while those of L-41b system showed up to 86.4 degrees C through the drop-in test. Cooling and heating capacities of R-32 and L-41b systems after partial optimization showed 99% and 101% of those of the R-410A system. Discharge temperatures of R-32 and L-41b systems after partial optimization were 81.8 degrees C and 85.2 degrees C under cooling standard mode, while they were 81.7 degrees C and 80.2 degrees C under heating standard mode. Pressure drops of heat exchanger by using L-41b after partial optimization were lower by 8% under cooling mode and 11% under heating mode for condenser and by 21% under cooling standard mode and 7% under heating standard mode for evaporator than those in case of drop-in test. (C) 2014 Elsevier Ltd. All rights reserved.