A Study on the Thermal Performance of Vertical U-Tube Ground Heat Exchangers.

Abstract: Based on the problem of underground vertical U-tube heat exchangers in ground source heat pump systems in Shenchi station of Shuohuang railway, the transient heat transfer physical and mathematical model of the soil and borehole temperature field is established. Finite element numerical simulation is made by virtue of MATLAB software. Through the method of numerical simulation, the paper analyzes the soil temperature, obtains the distribution of isotherms around the pipes and the scope of the heat transfer, and understands the heat transfer performance around the pipe intuitively. Based on the model and numerical solution, the paper analyzes the changes of temperature field about the soil around ground heat exchangers in different ways which involve geological conditions operating mode, layout, pipe depth, and pipe coupling interval situation, and then the dates are obtained to help the engineering design of ground heat exchangers. [Copyright &y& Elsevier]