Economy Evaluation On Ground-source Heat Pump And Study On Its Ground Heat Exchanger

Ground source heat pump (GSHP) air condition systems utilize ground soil as a heat source, exchange heat with the ground, it has been identified as a most environment-friendly and efficient system. In recent years has been paid widely attention in China, and some GSHP projects have been completed here. However, researches on the geothermal heat exchanger and the design and calculate of the underground tube are far form adequate. This situation impedes its application.Based on the summarization of the research of ground heat exchanger model theory, this paper mainly research thermal behavior of a single vertical U-tube underground heat exchanger in the ground. And for the theoretical model, a transient one-dimension unlimited long line source model outside borehole and a quasi three-dimension heat transfer model inside borehole are present. Analyzing the influence on heat transfer content per meter of designed outlet temperature of the circling liquid in underground heat exchangers, soil physical parameters, drilling depth, drilling diameter, tube material and someone else, combining figure out dynamic lord with modified BIN method, and then providing reference for the designing of the underground tube of the GSHP system.Choosing three kinds of commonly used cold source and heat source systems and carries on comparative analysis with GSHP system, obtained the result through calculating the initial cost and operating expenses of every project, and economic evaluation of every project is carried out with annual cost approach, analyzed the influence on the environment else. It shows that GSHP system has the beat annual cost, although its first investment is the most expensive. So the GHSP system has economy advantage and energy conservation.The ground source heat pump is a fresh domain in china, efficient and environment friendly, has a promising developing.