The Investigation Of Deposits Characteristics On Heating Surface Of Waste Incineration System

In the waste incineration system,the deposit on the heating surface is one of the factors affecting the safe and efficient operation of the entire power plant.At present,there has been a comprehensive study on the ash deposits of coal-fired boilers and biomass boilers.Due to the complex and diverse composition of waste,it is necessary to conduct in-depth research on the formation mechanism and growth characteristics of deposit in the waste incinerator.The deposit and ash samples from different parts of a commercial waste incinerators is analyzed in this article.At the same time,a experiment study on the influence of factors such as flue temperature,flue speed,and ash concentration to deposits growth rate is conducted.It is found that high temperature superheater and high temperature reheater are the two most serious positions in deposits.The reason for the difference in the ash composition in the vertical direction of the high-temperature superheater is that a sintering reaction occurs inside it.From the perspective of element distribution,the content of Cl in the inner layer of the ash is reduced,and the content of the S element is increased,which is the result of the sulfate reaction of the ash.The contents of Al and Si in the second and third flue ash are larger than those of the bag ash.The Cl in the fly ash is enriched with the flow direction of the flue gas.The crystals at the root of the ash deposit in the high-temperature superheater are densely sintered and bonded to each other.The surface of the crystal in the middle of the ash deposit has obvious melting phenomenon.Needle-like,crystal grains are more obvious.Low-temperature,medium-pass,low-pass,economizer and other low-temperature heating areas have relatively thin ash,the element distribution of ash is roughly the same,and the material composition is similar.The content of Al₂O₃ and SiO₂ in the fluidized bed fly ash is much higher than that of the grate furnace,and the alkali metal oxides such as Na₂O,MgO,K₂O,CaO in the grate fly ash are higher than the fluidized bed.Through the experiment study,it is found that the grouth rate of deposition is proportional to the ash concentration.A low flue speed can reduce the grouth rate of deposits.At the same time,a larger flue speed can also reduce the growth rate of deposition to a certain extent.There is a₈)at which the growth rate of depositon is largest,and it should be avoided during the design and operation of power plant.The growth rate of ash accumulation is positively related to the temperature of the flue gas,and it jumps up around 500?.A correlation model between ash concentration and smoke temperature and ash accumulation growth rate was established based on the experiment.