Evaluation System Of Comprehensive Benefit Indexes For A Geothermal Power Unit

In today’s world, with the increasing shortage of energy, a ground-coupled heat pump(GCHP) system as a HAVC technology in using renewable energy, features energy conservation and environmental protection, is internationally recognized as a high efficiency and energy saving technology. However, in practice, levels and abilities of equipment manufacturers, designers and contractors are in different levels, the construction and design companies did not do their performances according to the standards, so that make the design and application of GCHP systems with a certain degree of blindness. In practical applications, problems often occur, such as soil temperature imbalance in the winter and summer, low system efficiencies and so on, the energy-saving advantages of GCHP can’t be fully utilized, seriously affected the development of the GCHP technology.In order to make the GCHP develop healthily, safely, orderly and efficiently, design and applications of the GCHP become standardization, takes the characteristics of ground heat source heat pump system into account, according to the guidelines and the principles of the building, this paper build a set of scientific and effective evaluation system of comprehensive benefits for a ground source heat pump utilization. This system selects a total of 18 indicators to evaluate the benefit of GCHP systems from technology, energy efficiency, environmental and economic benefits for four aspects, and lists parameters need to be monitored and performance requirements of monitoring equipment are also be defined.This paper uses fuzzy comprehensive evaluation based on extension analytic hierarchy process to construct a hierarchical model of GCHP comprehensive benefit index evaluation system; and launches a consultation on importance of impact factors, then builds an extension matrix, obtain the weights of each factor by calculating the technical benefit, energy benefit, environmental and economic benefit accounting for 37%, 13%, 37.8%, 12.2% respectively; calculate the membership of indicators for four grades of evaluation; combine with the weights and membership of the various factors, fuzzy comprehensive evaluation values are obtained through a multi-level fuzzy evaluation; finally calculate final scores and grades of GCHP comprehensive benefit evaluation by using the weighted mean method.GCHP comprehensive benefit of a public building in Tianjin is evaluated by using the index evaluation system developed in this paper, composite scores of evaluation is 79.16, the comprehensive benefit of GCHP system standards general level, belonging to "E3" level. The evaluation results are consistent with the actual conditions, the effectiveness and feasibility of GCHP comprehensive benefit evaluation system are verified, the results are analyzed and evaluated, the problems are also be pointed out, and appropriate improvement advices and measures are proposed.In addition, this paper has developed a software suit to GCHP comprehensive benefit evaluation, this software has the advantage of science and operability, user can quickly and easily evaluate the comprehensive benefit of GCHP by entering the expert advice value and the actual test results, then comprehensive evaluation results can be outputted automatically.