Temperature-changing model of canal temperature affected by soil temperature in sewage heat pump

The wide utilization of urban sewage heat pump makes it necessary to recognize the coupling characteristic between trunk canal sewage and soil. The physical model and boundary conditions were analyzed during the heat elimination of trunk canal. Based on the dummy heat source image method, the soil temperature and the simplified condition were assumed. The soil temperature field around the trunk canal and the route temperature function of the trunk canal were analyzed in theory. In order to be utilized in project, the temperature-changing model of route canal was approximately treated as an instance. The research shows that it is difficult to obtain the exact solution due to the complexity of physical model and boundary conditions. The heat transfer coupling model between trunk canal and soil can be obtained by the analysis in theory, so the temperature field is a curved face taking the soil temperature in the same depth as the asymptotic line. The canal temperature tends to approximate the soil temperature with the burying depth, and it is determined by two characteristic constants. The simplified model is suitable for projects and meets the physical mechanics.