Modeling For Coaxial Tube Ground Heat Exchanger And Analysis Of Heat Transfer

Ground-Source heat pump (GSHP) which makes the ground as it'heat source, is a technique which economizes energy and protects environment. The article analyses the heat transfer process of coaxial tubes ground heat exchanger, and improved and modified an analytical model,a coupling model, based on the existence model, which deals with heat transfer of the flow in tubes and the heat transfer between tube and ground. The article calculated and analyzed the process on the basis of numerical method of finite element. Applying the finite difference principle, equations were converted into some discrete algebraic equations using the volume-control method, and the computational software solved this model in numerical method. Analyzing and exploring heat transfer characteristics and performance of coaxial tubes ground heat exchanger were implemented, including both cases of continuous process and intermittent process of changing load. Meanwhile, The article thoroughly researched the influences of some primary factors, such as the size of buried pipes, the velocity of flow in the pipe, the flow fluids, the thermophysical parameters of the ground, initial temperature of the ground, and so on.The results mainly displayed and showed the characteristics of temperature-time in flow fluids and the distribution of temperature field of the ground around the buried pipe.