Research On Building Applications Of Shallow Geothermal Energy In Hunan Province And Comprehensive Fuzzy Assessment Of GSHP

Currently, the world energy situation has become increasingly serious, and seeking for a new way of energy development is a very meaningful research subject. Ground source heat pump(GSHP) air conditioning technology, as a renewable energy application technology, is becoming mature in foreign countries, while in China, its application has just been started, and further researches are still needed. The common GSHP schemes include surface water heat pump, ground water heat pump, ground-coupled heat pump, sewage source heat pump and the seawater source heat pump.In this paper, with reference to a great many of recent literatures, the energy-efficient principles of GSHP is analyzed, and the characteristics of several schemes is pointed out. Then the building application status of shallow geothermal energy in Hunan province is investigated and analyzed, which includes investigations of the shallow geothermal energy resources and the building application status of ground source heat pump in Hunan province, and the usual problems for building application of ground source heat pump in Hunan province are pointed out as well.It is a common problem to make a optimization assessment of several GSHP schemes, because many decisions are usually made roughly and simply according to some single index, and which always brings with an unscientific result. Therefore, it is very necessary to make futher study of the optimization assessment of several common GSHP schemes. In this paper, based on the theory of fuzzy mathematics, a multi-criteria model of comprehensive assessment between several GSHP schemes is presented, and each factor’s influence to the optimization assessment results is analyzed as well.This paper mainly consists of three parts as follows:(1) Theory of the building application for shallow geothermal energy. This paper has introduced the energy-efficient principles, system composition and classification, and the common schemes of GSHP.(2) Investigation of the shallow geothermal energy resources status and the characteristics and status of GSHP building application in Hunan province. This paper introduced the situation of Hunan province, investigated the the shallow geothermal energy resources and the building application status of GSHP and discussed its characteristics in Hunan province. And at last, it points out some problems of GSHP application encountered in Hunan area.(3) Establishment of the comprehensive assessment model by fuzzy mathematics on GSHP scheme optimization. This paper has introduced the basic theory of fuzzy mathematics, the establishment of the comprehensive assessment model, and the evaluation of the grade of membership, the fuzzy evaluation matrix and the weighting vectors. Then analysis is made to get the relatively optimal GSHP scheme through an application example, using the model established in this paper. At last, it is analyzed for the influences to the assessment result caused by variation of the grades of membership for different factors, especially by the grades of membership for the initial investment cost and operation cost.