Method Of Design And Construction,Measurement In Summer Cooling Operation And Heat Transfer Modeling On Vertical Ground-coupled Heat Pump

Ground source heat pump (GSHP) is an air-conditioning technology with energy saving and environmental-production , it has been developed for half century in Europe and America but in China it is a very new technology .GSHP can be subdivided into groundwater heat pump (GWHP),ground-coupled heat pump (GCHP),and surface water heat pump (SWHP).Based on analysis and synthesis advantages and disadvantages of the three subsystems, every subsystem's trend of developing is made out and it is concluded that GCHP will have a promising future in China. Through referencing a great lot of newest research papers, this paper summarizes the latest research trends and results about vertical GCHP which is useful to direct our future research.The method of design and construction on vertical GCHP are in the period of inception in China. The author summarizes a set of easy and effective design method with the help of overseas design handbooks on GCHP. Through building a U-shaped vertical GCHP and testing it in cooling mode in Chongqing, the author assimilates other specialist's experiences and offers a practical construction technology on U-shaped vertical GCHP.The results of the test for U-shaped GCHP system in cooling mode are analyzed and synthesized in the third part of this paper. The test is divided three steps: (1) the first continuous run; (2) simulating run in public buildings; (3) all automatic adjusted run. Based on the test of some parameters of GCHP, we analyze the heat transfer performance of the ground heat exchangers with different backfills. This paper also shows the energy efficiency ratio of the whole GCHP and gives some suggestions for modifying and optimizing the method of design and construction.In the end, the author establishes a heat transfer model for ground heat exchanger of U-shaped GCHP. The model assimilates the latest results in the research and is solved by numerical approach which is called finite-difference equation。Combined with experimental system, this model simulates the temperature of the water which comes from ground heat exchangers and the round temperature field. The formula about the heat exhaust coefficient of the heat exchangers is deduced in this paper. The undisturbed ground temperature of the seasons' transitional days in Chongqing and the chart of some kinds of material's heat conductivities are given in the Appendix A and Appendix B . Appendix C shows the program of the numerical solution for the heat transfer model.