Theoretical Simulation And Experimental Investigation On Heat Transfer Of The U-pipe Vertical Heat Exchanger Used In Ground Source Heat Pump

This paper presented a systematic investigation of U-pipe vertical heat exchanger, established physical and mathematical models for U-pipe pile heat exchanger in order to solve the problem of heat transfer in different running situations and running times. Based upon the application of two-dimensional model of U-pipe pile, the temperature profile of multi-areas field and the expressions of heat transfer resistance between pipe wall and the borehole wall had been found. Heat exchange between the borehole and earth layer were deeply studied by Green function and dummy heat source, and detailed analyzed the application range and precision of three models: infinite line heat Source model, finite line heat source model and finite cylinder hole model.The experimental system on the ground source heat pump had been set up in Beiwu development area, Beijing. The data were collected real-time by the collecting-data implement in winter. In the same time, applying the new software named EED to design ground source heat pump system, it stimulated the temperature distribution of heat carrier fluid and the other datum in the design. In addition, from both the theoretic datum and the test datum, the difference between them can be found, and it also provides the practical method how to use the software properly.