Optimization Of Micro-energy Network Systems Based On Multi-Objective Evaluation Of Environment,Economy And Carbon Emissions

Energy is the basis for the progress of human civilization and socio-economic development.However,the extraction and use of large amounts of fossil energy has led to increasingly prominent ecological and environmental problems.With the rapid development of renewable energy,integrated energy systems have become an important research field in constructing a low-carbon,clean and sustainable energy system.As one of the main trends of the transformation of energy consumption methods in the future,the optimization design and operation of the integrated energy system is the key core.As micro-integrated energy systems,micro-energy networks can achieve multi-energy complementarity,make full use of renewable energy sources and reduce the dependence on external power grid,which is of great significance for enhancing the reliability and stability of regional energy system.However,micro-energy networks also face the problems of multi production capacity units and complex system composition,and how to achieve the optimal operation of micro-energy network systems has become a hot research topic in this field.In this paper,the micro-energy network system of a typical industrial park in Shandong Province is selected as the research object.Firstly,we conducted field research and data collection to understand the energy structure,capacity units,energy utilization situation and development planning in the industrial park.We used a life cycle assessment and cost accounting methods to evaluate the environmental impact,carbon emissions and economic costs of the current situation of the micro-energy network system.With the micro-energy network system operating for one year under existing load demand as the functional unit,the environmental impacts of the various capacity units were compared analysis using a"cradle to gate" system boundary.According to the results of life cycle assessment,the key impact categories were distributed among four categories,i.e.global warming,particulate matter formation,human carcinogenic toxicity and human non-carcinogenic toxicity.The sensitivity analysis of environment,economic and carbon emission revealed that when electricity purchased from the grid was reduced by 10%,the environmental impact,economic costs and carbon emissions will be reduced by 5.36%,6.05%and 5.78%,respectively.With the existing capacity of energy production units in the industrial park,electricity purchased from the grid was the key factor contributing to the environmental impact,accounting for 53.55%of the total environmental load;followed by central heating with 45.30%;solar PV and light pipes make small contribution,only accounting for 1.14%.On the basis of life cycle assessment,a multi-objective optimization model of microenergy network system was constructed.Based on the results of environmental impact and carbon emission assessment of the micro-energy network system,and combined with the economic cost,the model under the three objectives is stablished.We analyzed the optimization results of two representative months,December in the heating season and June in the non-heating season.The Pareto solution set of this multi-objective optimization model is solved by using non-dominated sorting genetic algorithm.On the front surface of the nondominated Pareto solution set,the potential analysis and comprehensive optimization solution selection are carried out from three perspectives of environmental,economic and carbon emission by combined weights-TOPSIS method.In the comprehensive optimization scheme,solar PV and light pipes were expanded by 100%and 50%,respectively.Nature gas units and air source heat pumps should be added for power generation and winter heating.The environmental impact of the optimized system was reduced by 34%-67%,the economic cost increased by 3.6%-5.2%,and the carbon emission decreased by 10.2%-24.3%.After the optimization of the micro-energy network system,the environmental impact and carbon emissions of the industrial park were greatly reduced,which is conducive to the construction of a cleaner and low-carbon energy system.This study established a multi-objective evaluation and optimization model for environment,economic and carbon emission of the micro-energy network system,which can provide theoretical and methodological references for structural adjustment and system optimization of micro-energy network system.