The Configuration Optimization Of The Solar CCHP System Based On Various Operation Strategies

Energy loss and environmental damage are important factors affecting the development of human society for a long time.Human development will be surely limited in the near future if we Ignore these adverse effects For Our country,in the past three decades,energy consumption has experienced rapid growth,which makes our government caused great concern on adjusting the structure of future energy consumption.Recently,the combined cooling heating and power(CCHP)systems attract much attention of researchers because of its prominent role in energy utilization.It can both reduce energy consumption and improve overall energy efficiency.The CCHP system is a complex system with a variety of equipment and components.The reliability of the whole system is closely related to the power generation unit,the heat recovery unit,the heat exchange unit,the cooling unit and the auxiliary unit.Therefore,it is necessary to optimize the configuration of CCHP system to make it run in the optimal configuration.From the perspective of energy utilization,the CCHP system has better energy saving and environmental protection characteristics compared with the separated supply(SP)system but the traditional CCHP system inevitably uses non-renewable energy sources such as coal and natural gas.Fortunately,new energy application technologies are developing at a high speed.Therefore,combining solar energy with traditional CCHP systems is considered an effective solution to alleviate the imminent energy and environmental challenges.This thesis proposed a new type of CCHP system,including the parabolic trough solar thermal(PTST)power generation and gas turbine power generation.This paper is based on the national natural science foundation of china and the research on scheduling control technology of photothermal power generation of the power system with high proportion new energy on the supply end.The research on this system conducts mainly from the following aspects:Firstly,the structure principle of the new system is introduced,the equipment composition of the system is defined,the model of each module equipment is established and the component selection is determined to lay a good foundation for the actual case analysis.The heat energy in the heat storage tank of the trough solar thermal power generator unit can not only generate electricity through steam turbine,but also be directly supplied to the client's thermal load demand at user side through the molten salt-water heat exchanger,so as to share the thermal load demand from the gas turbine.In addition,besides lithium bromide absorption refrigeration,screw type electric refrigeration is also added,that is,electricity can replace some of the heat needed for cooling.Therefore,the system can influence the configuration capacity of each module in the system simultaneously from the supply side and the user side.Then,the optimization objective mathematical model and solving algorithm are established.The objective function includes three indexes: economy,energy and environment.The hill-climbing algorithm is used in the solving algorithm,which is helpful to obtain the optimal solution set in the practical cases.A building cluster in Beijing is taken as an example to analyze the characteristics of the case.It is mainly divided into three aspects: First,the characteristics of operation strategy: based on the two modes of following electric load(FEL)and following thermal load(FTL),eight operation strategies are developed according to whether different refrigeration and heating modes are introduced.Second,the load characteristic analysis of the selected cases.Third,the mathematical model of solar radiation characteristics was established,and the characteristic curve was obtained by a simulation platform.Finally,the optimization results are analyzed to verify the correctness of the component model and the objective model.It includes the analysis of the optimal configuration results of each strategy,the comparative analysis of each strategy and the comparation between indicators under the optimal configuration of the optimal strategy and the indicators of separated supply(SP)system.