Study On The Slagging And Ash Deposition Mechanism And Performance Optimization Of Waste Incineration Power Generation System

The primary methods of waste disposal in China involve landfill composting and incineration power generation.However,serious slagging and ash deposition in waste incineration power generation requires immediate study.Most research methods involve experimental and numerical simulations but research deficiencies regarding the change law of ash melting characteristics and formation of the initial ash layer remain.Using molecular dynamic simulations,this paper constructed ash and deposition models obtained the change law of ash melting characteristics and simulated the initial ash layer formation with different heat exchange surface areas.Finally,a waste incinerator numerical simulation was conducted by CFD.Based on ash composition modeling produced by a waste power plant in Shanghai,five melt model components of Ca O-Al₂O₃-Si O₂-Fe₂O₃-Mg O were established,and molecular simulations of the ash obtained ash melting point and viscosity trends and the corresponding micro state changes.This research shows that for the ash of a waste power plant in Shanghai,using Si O₂,Mg O,and Cao additives reduced the ash melting point and played the flux role.Secondly,the formation of the initial slagging layer on the high-temperature heat exchange surface,the initial ash layer on the low-temperature heat exchange surface,and the effect of ash deposition additives were studied.On the high-temperature heat exchange surface,sulfide increased the adsorption energy of ash and alkaline metals on the equipment surface and the atomic root means square displacement.This implied sulfide accelerated the slagging speed and made slag removal more difficult.On the low-temperature heat exchange surface,initial ash deposition formation led to electron loss and an increased charge on the equipment surface material.Using coating materials with strong oxidation resistances effectively reduced ash deposition.The formation rates of initial ash deposition layers of nickel alloy,nickel-chromium alloy,and alumina coatings were 0.0063,0.0012,and 0.0047 respectively.This indicated ash deposition prevention of nickel-chromium alloy was the best and the nickel alloy was the worst.Additive use reduced potassium sulfate adsorption on the surface of the high-temperature heat exchanger turning cohesive ash into loose ash and facilitating blow ash.Among them,Ca O was the best additive.Finally,an incinerator slagging and ash deposition model based on the viscosity ash deposition criterion was constructed to analyze slagging and ash deposition in the furnace under the action of different additives.Without outside influences,Ca O and Mg O reduced slagging and ash deposition,while Si O₂ and temperature promoted slagging and ash deposition.