Numerical simulation and experimental validation on the heat transfer property of vertical buried tube ground heat exchanger

In order to study the effect of the arrangement of buried tubes on heat transfer, a three-dimensional heat transfer model of vertical U-shaped buried tubes is established. The regional thermal efficiency and soil temperature field around the buried tubes arranged in square array and rhombic array are numerically simulated. The numerical simulation results are compared with the experimental data to verify the correctness of the established model and simulation conditions. The results show that the rhombic arrangement form has more advantages than the square arrangement form: with the same number of buried tubes, the land use area of the rhombic arrangement form is smaller and the regional thermal efficiencies of the two forms are almost the same. The experimental validation shows that the experimental value of the average heat transfer rate of a single tube is in good agreement with the simulated value, and the relative error is 5.4%.