Dynamic Analysis On Heat Exchange Of Vertical Underground U-tube Heat Exchanger

Ground source heat pump is one kind of the utilization of renewable energy technology, which has been research focus in China in recent years. Key is the design and installment of underground heat exchanger, which has been research emphasis. The main research contents of this paper are as following:(1) A original heat transfer model of the soil temperature field was adopted. The soil temperature different depth was calculated in Chengdu. The effect of soil temperature surface on the distribution of soil temperature was analyzed.(2) And models of ground heat exchange for ground source heat pump were reviewed and summarized. The physical and mathematical model of the heat transfer was established for vertical two U-tube for ground heat exchanger.(3) Vertical two U-tube ground heat exchanger was simulated by ANSYS using APDL language. Effects on soil temperature field of soil thermal physical properties,external tube temperature,soil type and different material of backfill etc were obtained.(4) The heat transfer around Multiple-well for ground heat exchanger was simulated by ANSYS using APDL language. Monthly variation of temperature field was obtained.(5) A program for the design of vertical ground heat exchanger was developed using VB. It can calculate heat transfer rate per depth of single U-tube and double U-tube and the depth of well.The theoretical model,numerical calculation method and the program for the design of vertical ground heat exchanger are helpful to further study on ground source heat pump.