| Gas driven building cooling heating and power(BCHP)system with its high energy efficiency and environmental advantages of less polluting has been widely used in the current energy and environmental situation,however,this technology in our research and applications is still in its infancy and there are many problems in the system configuration and operation.In order to provide help for the future of this technology in the design and operation,this paper use the optimization method for the research of gas driven BCHP system rationalization configuration and operation strategy for the current status.Firstly,This paper introduces the system's basic equipment components and operating principles,and analyzes the performance characteristics of the main equipment.The system common configuration mode is established by induction,and the performance equations of each unit and system balance equations are established.Secondly,the article discusses the importance of accurate prediction of dynamic load to cogeneration system decision-making.Through the analysis of the traditional operation strategies,compromise thermo-electric operation strategy is proposed under hourly state.And further the hourly operation strategy,system capacity provisioning and configuration phased process optimization and solving method are established.Furthermore,the article selects system evaluation function from the economic,energy efficiency and environmental point of view.Based on an ideal point method combining with the traditional of supply system's characteristics,the negative ideal optimization method is built to determine the multi-objective optimization function of different stages.Then system's single-objective optimization and multi-objective optimization are analyzed in general under compromise thermo-electric operation strategy,and the scope of application of different types of generators and the hourly thermoelectric ratio optimized intervals are described from the perspective of user satisfaction.Multi-objective weights are determined by objective and subjective weighting method basing on the negative ideal point method,subjective weighting uses expert scoring and objective weighting uses entropy weight.Finally,this study method is applied to a real project,two feasible options are selected and decisions are maked.The optimal configuration is internal combustion engine which rated generating capacity is 3105 k W plus gas / direct fired absorption chiller which rated cooling capacity is 9910 k W plus electric heat pump of rated cooling capacity 2430 k W.Compared with separate supply system,combined supply system saves money which is equivalent to 20% in total cost,and increases the average primary energy utilization by 20.11%,and reduces carbon dioxide emissions by 58.89%.On this basis,the rationality and superiority of proposed operation strategy,optimization and empowering way are discussed.As the representative of a typical day in winter and summer,hourly operation strategy is shown,and then compared with the measured data to clarify the feasibility.Then the impact of energy prices is analyzed.Gas cogeneration system is not recommended when the proportion of gas and electricity prices is higher than 9 under the mode of merging with the grid.The system can sell excess electricity and get the benefit when the selling price of electricity is greater than 0.35 yuan per kWh under the mode of exchanging with the grid,and with the increase of tariff economic benefits are significant.In this paper,through the establishment of co-generation system optimized phased model and the instance's application and analysis,gas driven BCHP system configuration and optimization method is proposed.This method combines preliminary design and later operation effectively and lays the foundation for improving the system's actual operating results.This analysis method is also applicable to other cogeneration systems,so it has a high promotional application value. |
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