Optimization Simulation Of A 600MW Swirl Opposed Boiler With Different Type Coals

In the future for a long period of time,the dominant position of coal in the energy structure of our country won't change,improving the combustion efficiency of coal and reducing pollutant emissions is the most concerned issue.The research on the combustion process in the furnace has been quite mature and has been widely used.Blended coals are used in a 600 MW swirl opposed boiler of a power plant,numerical simulation research was carried out on this boiler by FLUENT software to study on the reducing of boiler efficiency due to the change of fired coals.Firstly,combustion conditions in furnace and NOx emission characteristics were studied with the design coals used under rated condition.Then simulation results were compared with actual operation data under design coals and the results coincide well.So the mesh model can be used to predict combustion condition and NOx emission characteristics of the boiler.Secondly,the numerical simulation of boiler in variable conditions were carried out to study the mass flow rate of over-fire air,the ratio of mass flow rate of inner secondary air to total and the outer secondary air vane angles on the characteristics of combustion condition and NOx emission for the boiler with four different groups of calorific value of coals.To select the optimum parameters from the two aspects of emission of NOx and the burnout rate of pulverized coal,as the basis for the combustion adjustment of the boiler.The optimal ratio of over-fire air,the ratio of mass flow rate of inner secondary air to total and the optimal outer secondary air vane angles were given under four different groups blended coals,which can provide some reference about combustion optimization for the actual operation of the boiler.