Characteristics of the ground temperature of the typical Ground-Source Heat Pumps system in Nanjing

Ground-Source Heat Pumps (GSHP) are often used to exploit the shallow geothermal energy.The designer of GSHP should take into account the variation of the ground temperature field after the operation of GSHP. In this manuscript, in order to analyze the spatial-temporal evolution of the ground temperature field, the bored concrete pile with GSHP and three observation wells (1.2 m, 2.1 m, 3 m) were all equipped with temperature sensors. The results demonstrate that the variations in temperature are smaller with the increasing of the horizontal distance from the bored concrete pile; the influence range of the underground soil temperature decreases and the heat transfer rate gradually decelerates as the increase of the depth. The variation equation of ground temperature with time and depth of energy pile and the change equation of ground temperature with time and distance were obtained by multiple regression analysis.