Research On Combustion Optimization Of 660MW Supercritical Unit Boiler

Power plant boiler is one of the most important equipment which translate the fuel chemical energy into heat energy. Boiler is a multiple input/output nonlinear complicated system. The operation of boiler is affected by many factors. Boiler needs to lower operationg costs as well as reduce the pollutant emission. The internal combustion process of boiler directly influces the boiler efficiency and the production of NOx. For these reasons, this paper carried out the research of boiler combustion optimization.This paper took one 660MW supercritical unit boiler in China as the research object, and single factor adjustment experiment has been carried out by changing multiple operation parameters in high, medium and low unit load(660MW,550MW,420MW). Based on the experiment data, the influence laws of operating parameters to boiler efficiency and the production of NOx were analyzed.This paper set up the SVR prediction model of low heating value of coal, the SVR prediction model of the carbon content in fly ash, the SVR prediction model of boiler efficiency and furnace outlet NOx concentration. Besides that, this paper used PSO optimization algorithm to optimize the SVR model parameters to make these established models precision high and improve the generalization ability.On the basis of the SVR models of boiler efficiency and furnace outlet NOx concentration, this paper introduced weighted factors to transform the multi-objective optimization problem into single objective optimization problem, then used PSO optimization algorithm to search for best input parameters. The influence of different weight ratio to optimized input parameters, boiler efficiency and NOx generation has been analyzed.Aiming at the flaws of the weighted factor, this paper directly solved the multi-objective optimization problem by using NSGAII multi-objective optimization algorithm, and then obtained the Pareto optimal solution set. Finally the most suitable solution can be chosen from this set.Boiler combustion optimization system was developed and integrated with the SIS in this paper.