Research On Comprehensive Evaluation Of Multi-energy Complementary System Based On Multi-attribute Fuzzy Decision-making

The energy Internet,as a way of transformation in the energy field,makes the multienergy complementary system become the focus of research in today’s world.The multienergy complementary system mainly achieves the coordination and optimization of the system,reduces the economic investment,improves the comprehensive utilization efficiency of system,and reduces the emission of pollutants through the complementary utilization of various energies,and finally realizes the reliable,economical,environmental operation of the energy system.At present,the multi-energy complementary system in China is in the early stage of development.The form of multi-energy complementary system is complex and varied,and there is a lack of relevant and perfect system evaluation criteria,which affects the innovation and development of energy Internet to a certain extent.Based on multiattribute index system and fuzzy decision-making,this paper studies the comprehensive evaluation of multi-energy complementary system,in order to solve the ranking problem among different types of multi-energy complementary system,and can provide reference for the optimal evaluation of multi-energy complementary system.Firstly,this paper introduces a variety of common technical forms of multi-energy complementary system from five aspects: power supply,heat production,refrigeration,gas supply and energy storage,and analyzes the benefits of multi-energy complementary system from four aspects: economy,energy,environment,and society.Secondly,based on the six major index selection principles,a multi-attribute mixed index system including 4 first-level indexes and 13 second-level indexes is established from the four aspects of economy,energy,environment,and reliability.According to the index attributes,the indexes are quantified and standardized,which can eliminate the magnitude difference among the indexes.It is proposed to deal with the fuzzy anti-entropy method by using the relative preference relationship between each index value and positive and negative ideal points,and the order relation analysis method is combined with fuzzy antientropy method by linear weighting to avoid the index weight being too subjective or objective.Then,based on the improved Euclidean distance theory,the fuzzy grey relational analysis method and fuzzy TOPSIS method are defuzzified,and an improved fuzzy GRA-TOPSIS optimization decision-making model is proposed.The decision model is used to comprehensively evaluate the multi-energy complementary system.Based on the mixed index system and the full fuzzy index system,the reliability of the improved fuzzy GRA-TOPSIS optimization decision-making model is verified,and the degree of differentiation between the schemes is more obvious.Taking the multienergy complementary system of an airport expansion project in Shaanxi as an example,the comprehensive evaluation and single evaluation are carried out by the improved fuzzy GRA-TOPSIS optimization decision-making model.The comprehensive evaluation results show that the multi-energy complementary system of ground-source heat pump,air-source heat pump,ice storage and natural gas triple supply is optimal in terms of synthesis.However,according to the single evaluation result,different types of multienergy complementary system have their own advantages at each level.According to the comprehensive evaluation of subjective weight,objective weight and combination weight,the results show that the improved fuzzy GRA-TOPSIS optimization decision-making model eliminates the influence of subjective and objective factors to a certain extent.Finally,the sensitivity analysis of the comprehensive evaluation results is carried out by changing index weight and the change of index weight has little influence on the comprehensive evaluation value of the scheme,which indicates that the improved fuzzy GRA-TOPSIS optimization decision-making model has good robustness in the aspect of index weight.In addition,the fluctuation of energy price will affect the economy of the system,so taking the payback period of investment as an index,through the sensitivity analysis of energy price,it is found that gas purchase price and electricity price have the greatest impact on economic indexes among the positive and negative correlation factors.