Research On Multi-objective Operation Optimization Approach Of Steam Power System Under Demand Uncertainty

Steam power systems,which consume a large amount of fossil fuels every year to meet the demand of steam and electricity in the industrial process,are important subsystems for industrial enterprises.Their safe and stable operation is the basis for the long-term operation of industrial enterprises.However,affected by the technological process,there is uncertainty on the demand side in the actual operation process,which brings certain challenges to the economical,safe and stable operation of the system.In addition,how to realize the rational utilization of energy has become the focus of current research with the gradually serious problem of energy shortage.Therefore,in this paper,the multi-objective operation optimization of steam power system under demand-side uncertainty is studied in enhancing the ability of system to deal with uncertainty,improving the economy,ensuring proper use of energy and maintaining the safety and stability of system production.Firstly,a multi-objective optimization operation model of steam power system including economic and exergy objectives is developed.Because different energies have different qualities,traditional energy efficiency analysis only considers the quantity of energy,without involve the quality.Therefore,in this paper,exergy analysis is used to evaluate the energy of steam power system to develop the exergy objective function of system.In addition,according to the characteristic that the operating efficiency of equipment can change with load,the variable efficiency model of equipment is established.Then,combined with the economic objective and energy constraints,a multi-objective optimization operation model of steam power system is developed.Secondly,aim at solve the problem that the mutual restriction between economic objective and exergy objective in the multi-objective optimization model of steam power system could not be optimized at the same time,the ε constraint method is adopted to transform the multi-objective optimization problem into the single objective,and the Pareto front of multi-objective optimization problem can be obtained.Then,the fuzzy decision method is used to determine the optimal operation scheme from the Pareto front.A case study shows that the multi-objective optimization of steam power system can balance the economic objective and exergy objective of the system and realize system optimization operation.In addition,the case also discusses the influence of coal price change on multi-objective operation of the system,which provides some theoretical reference for enterprise operation.Thirdly,considering that the demand side may change during the operation of the steam power system,by analyzing the characteristics of system demand change,it can be divided into two types of certain change and uncertain change.Based on the certain change of demand side,a multi-objective optimization model of the multi-period steam power system is developed.Aiming at the problem that the contradiction between the frequent start-stop of equipment in each period and the safe and stable operation of the system,adds start-stop logic and start-stop cost in the system model.The case shows that the system optimization model can obtain the optimal operation scheme,which not only reduces the operation cost and exergy input,but also reduces the start-stop frequency of the equipment.The optimal scheme can provide a guarantee for the safe and stable operation of the system.Finally,because the demand side uncertainty of the system is not taken into account in the multi-period steam power system multi-objective operation optimization model.Thus,A multi-objective optimization operation model of steam power system considering demand-side uncertainty is developed.The case shows that the model can make a practical operation scheme for steam power system with the better economic and exergy objective,strong operability and ability to deal with uncertainties.