Performance assessment and techno-economic optimization of ground source heat pump for residential heating and cooling: A case study of Nanjing, China

Abstract

This study implemented the performance assessment and techno-economic optimization of residential ground source heat pump (GSHP). First, a detailed numerical model integrating the ground heat exchanger and heat pump and economic model considering economic indicators were developed to analyze the thermal and economic efficiency of residential GSHP. Then, Taguchi method was proposed to investigate the impacts of five parameters on the thermal and economic performance of GSHP and obtain the optimal parameters set. After that, the sensitivity of optimal parameter to the drilling costs, pipe prices, and interest rate were performed. Lastly, the analysis of variance approach was implemented to find out the relative significance of parameters. Results revealing that the superiority of individual GSHP can be maintained in the vast majority of time and the capital investments are relatively high within the range of 13034.4 to 18199.2 CNY. The optimal parameters combination was of great discrepancies when taking the economic indicators into account. The most economical choice of pipe size remains unchanged, despite the optimization objectives and varying pipe prices. The relative importance of fluid velocity, borehole depth, and pipe material towards the variation of economic efficiency largely depends on the drilling costs, pipe prices, and the interest rate.