Energy and exergy analysis of ground source heat pump with low global warming potential refrigerant under Iraqi hot climate

The sources have a huge potential becoming sustainable sources and one of them is geothermal energy and its decisions making in context of GWP (Global Warming Potential) are of interest. This paper will discuss thermodynamic and exergetic performance of a Ground Source Heat Pump (GSHP) system with a refrigerant R410A which consists of vertical Ground Heat Exchanger (GHE) in the climatic condition of Baghdad. Experimental data were analyzed using Engineering Equation Solver (EES) software and were used to calculate the energy and exergy rates, which could then be utilized to examine the system in detail with respect to the key system components. In addition, an energy and exergy analysis of six low GWP refrigerants were carried out as an alternative to R410A at constant pressure ratio (3000 Kpa/700Kpa) detailed. The results indicated exergetic efficiency of the ground heat pump as 68.14% and 38.42% for overall system confirming high values of irreversibility losses particularly in the compressor and expansion valve. The analysis shows that R32 delivers the highest overall Coefficient of Performance (COP) of all other refrigerants studied at 2.388 and the highest overall exergy efficiency was obtained as 47.52% while exergy destruction was 36% higher than for R410A. R513A features thermodynamic limitation, and has a good exergy performance. The outcomes show thermodynamic consistency over the entire system and may prove beneficial in optimizing the efficiency and sustainability of GSHP.