Experimental and Numerical Investigations on the Heat Transfer Performance of a New Type of Energy Pile

Abstract

The ground‐source heat pump heating and cooling system is currently the most important development and utilization method of shallow geothermal resources, but its key component is the ground heat exchanger system. Herein, a new type of ground heat exchanger, the soil‐cement energy pile, is proposed. The similarity model comparison experiments of the soil‐cement energy piles and the soil energy pile in summer and winter were conducted respectively, and the 3D numerical models of heat transfer of the two kinds of energy piles are established, their related thermal properties are verified. Then the heat transfer calculation methods of the soil‐cement energy pile are presented and validated. The research has shown that the soil‐cement energy pile has good thermodynamic performance, which effectively reduces the largest thermal resistance in the heat transfer system of the energy pile, the thermal resistance of pile body material, and the heat transfer per linear meter of the soil‐cement energy pile is 21.20%–55.60% higher than that of the soil energy pile. The soil‐cement energy pile is of great significance to improve the thermal efficiency of the ground‐source heat pump system and can reduces the overall project cost.