Analysis on the energy efficiency of geothermal heat pump for a high-rise office building

This paper analyzes an air-conditioning system of an actual project in Tianjin, China that uses geothermal and water loop heat pumps (GWLHP) in winter. The concept of exergy has been introduced to establish a universal efficiency evaluation standard for this kind of geothermal heat pump system. In the paper, the energy and exergy analysis of the GWLHP system in the whole winter were conducted together. We compared its primary energy consumption with that by using hot water from the city heating network. An exergy assessment and modeling of the geothermal heat pump system were studied as well. Basing on the analysis above, the exergy efficiency value of the GWLHP is 48.45%, and the geothermal heat pump system can save more energy enormously than normal heating system with heating network. This study also analyzed its economical and technical feasibilities by using geothermal heat as the sole heating source.