Comprehensive Evaluation Of Distributed Energy System In Rural Areas Based On Combination Weighting

With the promotion of the "rural revitalization strategy",the demand for energy of rural residential buildings in our country has been increasing,and it has gradually become an important part of domestic building energy consumption.In addition,the current energy utilization mode in rural areas presents high pollution and low efficiency.In the context of the increasingly prominent contradiction between energy consumption and environmental protection,distributed energy systems are gradually applied in rural areas of our country as a regional energy supply technology that is energy-saving,environmental protection,flexible and reliable in energy supply.Considering that the comprehensive evaluation of distributed energy systems has always been an important part of research work.In addition,there is a lack of relevant research and exploration on the application in rural areas,so it is necessary to evaluate the application of distributed energy system in rural areas.It can provide a basis for the feasibility of the application and promotion of distributed energy systems in rural areas in the future.This paper firstly analyzes the theory and characteristics of distributed energy system,and the operation characteristics of critical equipment in distributed energy system,and established evaluation indicators about energy efficiency,economic and environmental performances.Then,according to the theory of multi-attribute decision making,a multi-attribute comprehensive evaluation model based on combination weighting is proposed.Finally,the model is used to evaluate the case of distributed energy system in rural areas.The main conclusions are as follows:(1)The user-side load of the demonstration project is calculated based on the information obtained from field research and in combination with relevant energy-saving standards.The results show that residential buildings in rural areas have the characteristics of higher heat-to-electricity ratio than urban areas.In addition,according to the characteristics of the electric load on the user side,it is found that rural areas are small-scale regional power supply objects and the electric load fluctuates greatly throughout the day.By comparing the operating performance of various power generation equipment in distributed energy systems,it shows that the internal combustion engine is the best choice as the power generation equipment of the distributed energy system(2)The operation performance of distributed energy system is analyzed according to the established evaluation indicators.Taking this case as an example,compared with the traditional centralized energy system,the distributed energy system can save 7.18% of energy consumption.In addition,from the evaluation results of the multi-attribute comprehensive evaluation,it can be seen that the comprehensive benefit of the distributed energy system is greater than the traditional centralized energy systems.The results show that it is feasible to apply the distributed energy system in rural areas.(3)Based on the proposed combination weighting method combining subjective and objective,the weight proportion of each evaluation indicators is calculated.The results show that the subjective and objective combination weighting method can solve the problem of poor indicators weight accuracy caused by single weighting method.In addition,it can be seen from the weighted sum of the indicators that the weights of the three attributes of energy efficiency,economy and environment are:0.2784,0.4738,and 0.2478.The results show that the evaluation indicators of economy is the pivotal factor affecting the comprehensive benefit of distributed energy system.In rural areas,the economics of the system should be considered first when determining the operation scheme of the distributed energy system.(4)The multi-attribute comprehensive evaluation model constructed is used to comprehensively evaluate the distributed energy system of the case.The results show that the comprehensive benefit of the distributed energy system in the "grid-connected operation" operation mode is higher than that in the "independent operation".The comprehensive benefit of the distributed energy system fueled by biogas is greater than that natural gas in the same operation strategy.For rural areas with relatively abundant biomass energy storage,biogas can be considered as the fuel of distributed energy system.