Techno-economic analysis of Al2O3/CuO nanofluid applied in various horizontal ground heat exchangers

A ground source heat pump (GSHP) is widely regarded as a promising technology for building heating, ventilation, and air conditioning because of its higher energy efficiency. Nanofluids (NFs) have also received extensive attention due to their excellent heat transfer characteristics. In this paper, CuO/Al2O3 particles mixed with propylene glycol/water (PG/W, volume ratio: 60/40) are applied to GSHPs as a heat transfer medium. The combination of different pipe types and different concentrations of NFs is studied by comparing the coefficient of performances (COPs) and outlet temperatures. The results show that the 2% CuO NF combined with the spiral type offers the best performance with a 28% rise in the outlet temperature in the pipe and an average COP value of 4.6. When the concentration of Al2O3 NF is 2%, the combined effect of the meander type is the best. The optimal combination of CuO (2%) and spiral type is used for economic analysis by comparing with the performance of natural gas boilers, air source pumps, and GSHPs under similar conditions. The levelized cost of heat analysis results indicate that the horizontal GSHP system coupled with NF can maximize heat exchange efficiency and mitigate environmental effects, but the cost is still high as 1355/MWh ($212.46/MWh).

Automated summary

This study explores the application of CuO/Al2O3 particles mixed with propylene glycol/water as a heat transfer medium in ground source heat pumps, aiming to improve heat efficiency and performance by studying different pipe types and NF concentrations. Results indicate that certain combinations can significantly increase outlet temperature and achieve higher COP values.