Research On The Optimization Of The Structure And Operating Parameters Of The Landfill Leachate Concentrate Incinerator Based On The "3T+E" Principle

In most countries,sanitary landfill is currently the most commonly used means to eliminate municipal solid waste.Despite its many advantages,sanitary landfill will produce landfill leachate,causing serious pollution to the surrounding environment.Landfill leachate concentrate has complex composition and high COD concentration,which is a kind of organic waste liquid that is difficult to treat.Generally,for this kind of high COD organic waste liquid,the incineration method is an economical and effective treatment method,and how to realize the efficient and clean incineration of the organic waste liquid is currently an urgent problem to be solved.In this paper,a landfill is used as the engineering application background,based on the "3T+E" principle,and the method of numerical simulation is used to study the structural parameters of different incinerators(burner arrangement and nozzle arrangement height method),the outlet flue gas temperature,the residence time of the flue gas in the second combustion chamber,the turbulence energy in the incinerator,whether the outlet flue gas has an appropriate amount of excess oxygen,and the burn-out rate of concentrated liquid droplets.On this basis,appropriate incinerator structure parameters were selected,and the effects of concentrated liquid atomization particle size,concentrated liquid incident speed,concentrated liquid nozzle atomization opening angle and excess air coefficient on the combustion process of concentrated liquid in the incinerator were studied.The main research results are as follows:(1)Through the research on the operation of different structures of waste percolation concentrate incinerators,the best burner arrangement and swirl direction of the incinerator and the best height of the nozzle arrangement are obtained:(1)The symmetrical arrangement of the burners,the reverse swirling and the symmetrical arrangement of the same rotating swirling arrangement,are more conducive to waste percolation and concentration.The combustion of liquid in the incinerator;(2)When the height of the nozzle of the incinerator is too high(1m～1.2m)or too low(0.5m～0.6m),it will cause the concentrated liquid droplets to hit the wall,and the concentrated liquid cannot completely evaporate and burn,which is not conducive to the stable operation of the incinerator;When the arrangement height is slightly higher than the center line of a combustion chamber(0.7m～0.9m),the concentrated liquid can greatly reduce the wall collision rate and complete the evaporative combustion.(2)Through the study of the incineration process of the waste percolation concentrate under different operating parameters,the operating parameters such as the optimal initial atomization particle size,the incidence velocity of the concentrate,the nozzle atomization opening angle and the excess air coefficient of the incinerator are obtained:(1)On the premise of meeting the burn-out rate of the concentrated liquid,in order to allow the atomizing nozzle to pass through as large a foreign body as possible,the initial particle size of the nozzle after atomizing the concentrated liquid droplet is150μm,which is the optimal initial atomizing particle size;(2)Considering the complete combustion rate of concentrated liquid droplets in the incinerator,when the initial incident velocity reaches 18m/s,the incinerator has a better operating effect;(3)When the atomization angle is 60°,the temperature distribution in the incinerator is more uniform and concentrated Liquid droplets have a higher complete combustion rate;(4)To meet the "3T+E" principle,the most suitable excess air coefficient is 1.1.(3)Analyze and evaluate the combustion results of the concentrated liquid in the incinerator under the best furnace structure and the best operating parameters:(1)The temperature field and the distribution of main components in the incinerator under the best optimized working conditions are analyzed.Under the best optimized working conditions,the concentrated liquid can be completely vaporized and burned in the incinerator,and the furnace is full of good and no dead corners.;(2)The best optimized operating conditions were evaluated based on the quantitative criteria in the "3T+E" principle.The operating state of the incinerator meets the "3T+E" principle.The outlet flue gas temperature is greater than 850℃ and the residence time of the flue gas in the second combustion chamber is greater than 2s.