Study On Operation Optimization Of Power Plant Wet Desulphurization System Based On Data Drive

With the increasing of environmental protection requirements in China,the sulfur dioxide content in the flue gas discharged by thermal power units has been strictly monitored.Limestone-gypsum wet desulfurization technology has th e advantages of low investment,high efficiency,safety and stability,so it has been widely used.However,the consumption of limestone,water and electric energy in limestone-gypsum wet desulphurization system is also considerable,and the energy-saving optimization of desulphurization system has become the main concern of power plants.In this paper,the desulfurization system of unit 3 of a600MW unit in a Shanxi power plant is taken as the research object.Combined with the operation data of the unit,th e economic operation of the desulfurization system is studied under the constraints of environmental protection requirements and operation safety.Firstly,based on the long-term historical operation data of the unit,the operation characteristics of the desulphurization system were analyzed,and eight main factors affecting the desulphurization efficiency were determined through the operation mechanism analysis.On this basis,the correlation calculation was carried out by using the mutual information meth od,and finally five key factors affecting the desulphurization efficiency were determined.Secondly,extreme learning machine（ELM）algorithm was used to model the desulfurization system.Aiming at the problems of E LM’s excessive dependence on the number of hidden layers and strong randomness of parameter selection,particle swarm optimization（PSO）algorithm was used to optimize the parameters of ELM model.The simulation results show that the model has high prediction accuracy,and the model can stably follow the variation of desulfurization efficiency when it fluctuates violently with time.Then,based on the economic analysis of the desulfurization system,the optimization principle of taking the power consumption of slurry circulating pump as the optimization objective and taking the SO₂ concentration and pH value of the desulfurization outlet as the constraint conditions was established,and the economic operation rule library of the desulfurization system was established,so as to realize the optimization guidance of the online operation of the desulfurization system.Finally,the optimized strategy is applied to the actual site,and the data before and after the optimized operation are selected respectively.By comparison,it is found that the optimized desulphurization system saves 18.1%power consumption and 2.5%limestone consumption on average.Certain effect of energy saving and consumption reduction has been achieved.The research of this paper has important practical significance for promoting the safe and efficient operation of desulfurization system in thermal power plant,reducing the operation cost of power plant and saving operation cost.