Research On System Optimization And Energy Policy Incentives Of Natural Gas Distributed Energy System

As an on-site energy supply system,distributed energy system could be effectively in utilizing clean energy and energy cascade utilization and it could reduce energy loss in transmission and distribution compared with traditional centralized energy supply system.Distributed energy system could play a significant role in efficient utilizing of energy and greenhouse gas emissions reduction.However,because the initial investment of distributed energy system is relatively high,the system configuration cannot match the load very well and the implementation of relevant policies are not in place,the development of distributed energy systems is not satisfactory.Therefore,based on the simulation of building load,this dissertation will focus on the research about system configuration optimization and policy incentives of natural gas distributed energy system.Firstly,a distributed natural gas energy system model was built in this dissertation.Then,the key equipment in the system,such as the driving device and waste heat utilization device were modeled based on the energy conversion.The mathematical relationship between the input and output of each device and the energy consumption,emissions and costs in operation which were related to the energy input were established.Secondly,the system evaluation index was established considering the economy,energy consumption and emission performance of the system.Based on the balance of energy demand and supply,a multi-objective optimization model of distributed energy system was built and the analytic hierarchy process was applied to determine the weight factors of each objectives.Finally,a two-stage optimization method for the operation and design of distributed energy system was proposed in this dissertation.Thirdly,the model of hotel,hospital,residence and office buildings were set up in the energy consumption simulation software DeST to simulate the annual hourly cooling,heating and electric loads of four buildings.The annual loads,monthly loads and hourly loads of typical days of four buildings were analyzed in this dissertation,respectively.According to the system optimization methods above,the optimal system configuration with energy storage and without energy storage of four buildings were obtained.The annual economic,energy and carbon reduction performance of distributed energy system of four buildings were analyzed,respectively.From the perspective of monthly energy supply and hourly energy supply in typical day,the impact of energy storage in system configuration were analyzed in this dissertation.Finally,taking the hospital as an example,the influence of engineering subsidy,natural gas price and feed-in tariff on the existing system and system design were studied in this dissertation,respectively.The impact of capital subsidies on the performance of distributed energy systems was relatively small.The natural gas price influenced the economic performance of the distributed energy system directly.The feed-in tariff policy had a great influence on the comprehensive performance of distributed energy system.From the point of no connection to the grid-connected but the selling price was zero,the system performance all increased about 5%.When the proportion of electricity selling price was between 60%-80% of the current electricity price,the system would achieve better economy while the carbon emission reduction and energy saving performance were as good well.