| Compared with the traditional separate energy system,building distributed multi energy coupling system can realize the cascade utilization of energy,improve the efficiency of building energy utilization and reduce the environmental impact,which is an important part of building energy supply in the future.At present,the research on building distributed multi energy coupling system modeling at home and abroad mostly focuses on the comparison between different systems of a certain operation strategy,and lacks the comparison between different operation strategies of a certain energy system,the optimization of operation strategy mainly adopts multi-objective optimization method,in which the equipment models are mostly simplified models,and lack of consideration of the influence of variable working conditions and environmental conditions on equipment.In this paper,the physical models of photovoltaics,ground source heat pump,combined cooling,heating and power(CCHP)system and heat storage water tank are built on the Simulink platform,and the module coupling is carried out according to the three operation strategies of following the thermal load(FTL),following the electric load(FEL)and following the electric load with heat storage(FELHS),a typical building in Wuhan is studied,and the life cycle assessment(LCA)method is further used to analyze the energy,economy and environment performance of the building distributed multi energy coupling system under three operation strategy,then the comprehensive evaluation method is used to obtain the best operation strategy.The main conclusions are as follows:(1)The FTL operation strategy and the FEL operation strategy will cause a large amount of power and cooling(heat)surplus respectively,and the matching degree between the cooling and heat output of the system and the building load will be greatly improved by using the FELHS operation strategy.The borehole wall temperature rise of the ground heat exchanger after ten years is the smallest under the FELHS operation strategy,which is only1.45℃.(2)Gas turbine and ground source heat pump contribute a lot to the life cycle of the system in greenhouse gas emission,the greenhouse gas emission of the system is the smallest under the FELHS operation strategy,the results of sensitivity analysis show that reducing energy consumption and adding carbon capture equipment are the key to effectively reduce greenhouse gas emission.(3)The non renewable primary energy utilization rate of operation strategy of FTL,FEL and FELHS are 51.49%,86.78%,125.69%respectively,and the system annual dynamic value of operation strategy of FTL,FEL and FELHS are 1.05×10~6CNY,7.23×10~5CNY,5.94×10~5CNY respectively,the levelized cost of energy is the lowest under FELHS operation strategy,which is 2.12 CNY/k Wh.The comprehensive evaluation results show that the comprehensive performance of the FELHS operation strategy is the best.The research of this paper can provide reference value for the construction of building distributed multi energy coupling system,and has obvious guiding significance for the comprehensive optimization of its operation strategy from multi perspectives of energy,economy and environment. |
