Analysis Of The Emission Characteristics Of Particulate Matter In Coal-Fired Boiler Flue Gas

At present, there are many factors that affect the environmental quality, fineparticles with small particle size is one of them. These fine particles have aninescapable responsibility for the human health, global climate change,especially PM2.5、PM10and so on. With the rapid development of economic inChina, electricity load continues to increase, particles emissions from coal-firedpower plants increased year by year, so the particle emission standards isbecoming more and more strict for coal-fired power plants in our country.This paper according to the different types situation of coal in the actualpower plants operation, taking the fine particulate matter emissions in600MWcoal-fired power generation unit as the experimental object, and combining thegiven different load conditions of electrostatic precipitator, the particulateemission characteristics were analyzed, obtained:(1)With the increasing of the boiler load, the dust removal efficiencydecreased, and the two are related closely.(2)When the fluctuation range of the coal moisture, volatile matter, fixedcarbon is not big, the content of the coal ash is higher, the dust removalefficiency is lower;(3)Handled the processing of plant samples by using the particle sizeanalyzer, can found that the removal of dust particle in respective electric fieldand the proportion of capture effect on the particle size less than1μm isincreasing step by step from the first field to the forth field. However, the resultis opposite for particle size greater than10μm.In addition, it obtained the distribution law and variation characteristics ofthe fine particles in electrostatic precipitator by using the numerical calculationsoftware FLUENT. Studies the relationship between entrance dustconcentration, entrance velocity, potential voltage, plate spacing and thecollection efficiency of the electrostatic precipitator systematically. Aquantitative conclusion was made: with the increasing of voltage(30-70kVrange), the dust removal efficiency improved; with the increasing of entrancedust concentration(5-20g/m3range), the dust removal efficiency decreased; with the flow rate increased, the dust removal efficiency increased when theflow rate is lower, however it decreased with the flow rate increase when theflow rate is greater than a certain value; the dust removal efficiency increasedwhen the plate spacing changed from0.3m to0.4m, it decreased when the platespacing changed from0.4m to0.5m. It provided a basis for the research ofelectrostatic precipitator in future by comparing the experimental andnumerical simulation results.