The Effect Of Seasonal Variation On Thermal Performance Of Horizontal Slinky-Loop Ground Heat Exchanger

For ground-source heat pump (GSHP) installations, it is important to predict the thermal performance and economic feasibility prior to the introduction of the system. Numerical modelling can be used as an analytical method to accurately predict the thermal performance of such system. It is desirable that the modelling to incorporate seasonal variation during long period of operation, which would lead to a better understanding of the overall performance and provide more reliable results. In this work, numerical modelling performed using computational fluid dynamic software presented the heat exchange rate for different operation of slinky loop ground heat exchanger (GHE) using timeand position-varying parameters. Each operation were carried out in short and long simulation periods during winter and summer conditions of southwest of Japan, specifically in Saga City. This analysis suggested that heat flow in GHE operation was more dominant along vertical axis. It also supports the common claim that heat exchange rate is predominantly limited by the thermal conductivity of the ground. Spaced loops in multiple parallel GHE helped to minimize the interference of heat flow that would penalize the overall thermal performance.