Analysis of Temperature Field and Stress Field around Vertical U-Tube Exchange Used in Ground Source Heat Pump

Abstract

Basing on coupled thermal conduction and groundwater advection conduction, this paper analyzed the effects to the temperature field and the stress field caused by the Vertical U-tube exchange used in ground source heat pump. And then this paper analyzed the relationship between heat influence radius and thermal conductivity and groundwater advection velocity. Also, we obtained the simple formula which can estimate the heat radius of influence. Basing on coupled thermal conduction and solid mechanics analyzed the stress field caused by thermal expansion. The results show that: without groundwater advection, the heat radius of influence linear correlate to the thermal conductivity; the radius will obviously expand when the groundwater advection velocity is not too small; the stress field caused by thermal expansion near the U-tube is much larger than the farther region and it will trends to balance with the distance increasing.