Performance comparison of heat pumps using low global warming potential refrigerants with optimized heat exchanger designs

Abstract

The objective of this study is to analyze the performance improvement of heat pumps with low global warming potential (GWP) refrigerants over conventional R-410A heat pumps by optimizing the heat exchanger designs. A simulation model is developed for heat pumps with low GWP refrigerants and validated by comparing the predicted and measured data for R-410A and R-32. Based on the developed model, the diameter of the tube and the number of paths in the indoor and outdoor heat exchangers are optimized for each alternative refrigerant using the genetic algorithm. The performances of the optimized heat pumps with the low GWP refrigerants are compared with that of the R-410A heat pump to provide a selection guide for alternative refrigerants. The average performance improvements of the heat pumps with optimized heat exchanger designs were estimated to be 6.0%, 3.4%, and 2.4% for R-32, DR-5, and L-41a, respectively, compared with that of the baseline system. Thus, the R-32 heat pump delivered the highest performance improvement with the optimized heat exchanger designs.