Simulation Study On Combustion And Desulfurization In 600MW Pulverized Coal Boiler

In the context of large-scale use of coal resources,it brings about negative effects such as haze and air pollutants.Oxygen sulfide is one of the pollutants after combustion.China's SO₂emissions have exceeded 10 million tons for many years,so it is urgent to reduce SO₂emissions from coal-fired boilers.In this paper,the SOx situation of a coal-fired boiler in North China will be simulated and improved to explore the pollutant situation before and after the improvement.This paper aims at a 600MW coal-fired boiler in Heilongjiang Province.According to the actual drawings provided by the cooperative unit,a 1:1three-dimensional physical model is established,and the calculation area is divided into professional grids.According to the research focus direction,the model is simplified and the boundary is set and selected,and the calculation model and method suitable for the research content are selected.FLUENT software is used to simulate the operation data of the model.Multi-point temperature data collection is carried out for the boiler in actual operation.Under the same operating condition,the temperature data collected in the boiler is compared.After verification,it is found that the trend of simulation value is basically consistent with the actual operation value and the error range is allowed.It is considered that the calculation method of this simulation and the applicability and accuracy of the model can correctly reflect the SOx situation.Furthermore,the structure of the original boiler model is improved to increase the desulfurization mechanism.The diameter of desulfurized particles injected into the furnace is set as 200?m,400?m and 600?m respectively.The improved combustion and the distribution of SOx concentration under different diameter of desulfurized particles were studied,and the desulfurized efficiency of three different diameter particles was calculated.After comprehensive analysis,it is concluded that the maximum desulfurization efficiency is obtained when the diameter of desulfurized particles is 200?m,and the average concentration of SO₂in the furnace is reduced from 429.4mg/m3under the original operating condition to 146.0mg/m3,which meets the national pollutant concentration standard.In this diameter,the desulfurization efficiency is the highest under three conditions,and the desulfurization effect is the best.The simulation methods and research methods in this paper are suitable for this furnace type,and can also provide theoretical basis for similar furnace type.In the selection of desulfuration method in tangentially fired boiler,the desulfuration particles with diameter of 200?m can be selected.This desulfurization method can achieve higher comprehensive desulfurization efficiency with the flue gas desulfurization method outside the boiler.This paper also provides theoretical support for the transformation of the old medium sulfur pulverized coal boiler.