Structure optimization for horizontal ground heat exchanger

With the advantages of lower installation cost and lower drilling technology requirement, the horizontal ground heat exchanger (HGHE) has attracted much attention. In this paper, the pipe arrangements with in-line and staggered are evaluated comparatively and the effects of the relative displacement of staggered pipes are investigated. Meanwhile, the comprehensive effects of bending number, pipe spacing and buried depth on thermal performance of HGHE are studied. The results show that the thermal performance of staggered arrangement outperformed that of in-line arrangement when the relative offset displacement is greater than 1/3. The thermal interference between adjacent buried pipes is the significant factors causing thermal resistance. For double-layered HGHE, the critical pipe spacing of first layer and second layer is 40d and 100d respectively. The buried depth has little effect on the thermal performance of HGHE.