Abstract: In this paper, a one-dimensional seepage-heat transfer model test-bed is built to study the influence of seepage velocity and direction on the heat transfer characteristics of buried pipes. Based on the theory of heat transfer in porous media and groundwater flow, a simplified three-dimensional numerical model was established through the simulation software COMSOL Multiphysics, and the calculated value was compared with the measured value to verify. The research shows that the effect of groundwater flow on the original medium-sand temperature field is as follows: at lower seepage velocity, the effect of seepage can be ignored, and at higher seepage velocity, seepage enhances heat transfer. And the higher the seepage velocity, the stronger the heat transfer effect. The influence of the seepage direction on the temperature field of the middle sand is the heat transfer range.  When the seepage direction is opposite to the heat transfer direction, the heat transfer range is small, which can be used as a reference basis for the arrangement of buried pipes. After simulation verification, the result error is small, and the established physical model is relatively reliable.

Key words: Model Test, Thermal Seepage Coupling, Horizontal Seepage, Simulation Verification, Multi-Field Coupling