Research On Operation Strategy Optimization Of Distributed Multi-energy CCHP System

With the increasingly severe problems of energy and environment,the country pays more and more attention to the development and utilization of energy,and vigorously promotes the utilization of renewable energy.The combined cooling heating and power(CCHP)system has aroused people’s attention because of its multi-type energy supply,the cascade utilization of multiple energy sources and the high utilization ratio of primary energy.Therefore,the combination of the traditional CCHP system and the renewable energy has become a hot research direction.One of the most concerned issues is the strategy of the system’s operation.Whether the system’s operation strategy is reasonable or not directly affects the advantages of energy saving,economy and environmental protection.Under this background,this thesis focuses on the distributed multi-energy CCHP system composed of renewable energy sources,energy storage devices and CCHP system core equipment.In order to improve the overall performance of the system,different operation of distributed multi-energy CCHP system strategy is optimized and verified by an example simulation.The results show that the proposed strategy is effective and economical This thesis mainly completed the following aspects of the work:Based on fully considering the variation characteristics of the thermoelectric efficiency of the micro gas turbine with load,the quantitative relationship curves between them is given,which provides a theoretical basis for selecting of the efficiency parameters of the micro gas turbine.In addition,the mathematical model of distributed multi-energy CCHP system unit is established by analyzing the characteristics of three types of equipment in power generation,heating and cooling in distributed multi-energy CCHP system and the parametric equation of wind turbine units based on data fitting is given,which lays the foundation for the system’s strategic optimization index system.Considering the shortcomings of the distributed multi-energy system running under the two traditional strategies of FER and FTL,a hybrid multi-energy system operation strategy(FHL)based on electrical and thermal energy storage devices is proposed.An index system of comprehensive performance evaluation of energy-saving,economy and environmental protection and the optimization model of distributed multi-energy system are established.A hybrid operation strategy optimization method of distributed energy system based on energy storage is given.The optimization of the multi-scenario distributed multi-energy system operation strategy is realized.Simulation results show that the hybrid strategy based on stored energy distributed multi-energy system proposed in this thesis is superior to the traditional FEL and FTL strategy.Aiming at the problem that the FHL operation strategy may cause insufficient energy supply for distributed multi-energy systems under some conditions,an evaluation index system for the matching degree between the cogeneration unit and the overall system is established.A running strategy based on minimum distance(MD)is proposed.Compared with FEL,FTL and FHL strategy,this strategy improves the overall performance of distributed multi-energy system.Finally,based on the minimum distance(MD)operation strategy,the optimal output curve of typical days in different seasons is given,which verifies that the proposed strategy not only has a high degree of system performance matching but also ensures the system’s operation efficiency and economy.