Study On Optimal Operation Of Thermal Power Unit Desulfurization And Denitrification System

At the present stage,Domestic power plant units have completed the transformation of desulfurization and denitrification on the whole.The desulfurization and denitrification system effectively controlled the SO2 and NOX emissions of thermal power units,but it brought a great additional cost for the power plant.Therefore,to reduce the cost of desulfurization denitration system by optimizing the operation mode under the premise of the pollutant concentration below the emission standards is the researchers’ goal at home and abroad,since the industrial application of desulfurization and denitration technology.A year actual operation data of desulfurization and denitration system in a 350 MW coal-fired power plant is took as the research object.Firstly,the data was preprocessed to be a data set with complete parameters,unified format and without missing and wrong data.Then,the pollutant removal efficiency(desulfurization efficiency and denitrification efficiency)prediction model was established with full load by the Support Vector Machine(SVM),and results showed that the model can accurately predict the full-load pollutants removal efficiency with great generalization ability,and meet demand of the actual project.According to the cost calculation method and reaction mechanism,the environmental protection cost per kW · h calculation model was established with combination of the power plant actual operation.Based on the environmental protection cost per kW · h,the optimization model of environmental protection system was established with the combination of Support Vector Machine(SVM)and Chaotic Particle Swarm Optimization(CPSO),and used this model to optimize the preprocessed historical operation data grouped by the load and coal variety.The optimization results showed that the environmental protection cost per kW·h after optimization was greatly reduced with the premise that pollutants concentration meet the pollutants emission requirements,and the average reduced relative value was 90.4109%.It proved that this model could significantly improve the economic of the environmental protection system.Finally,the contrast of the two kinds of optimization methods influence on optimization results was conducted,and the optimization methods are the environmental protection system(desulfurization system and denitration system)comprehensive optimization based on the environmental protection cost per kW·h,the desulfurization system and denitration system separate optimization respectively based on the desulfurization and denitration cost per kW·h.Results showed that,the optimization methods have little effect on optimization results,but the comprehensive optimization is with a more concise algorithm,shorter operation time and greater practicability.