垃圾焚烧电厂飞灰在固定床中烧结的数值模拟

针对某垃圾焚烧飞灰固定床烧结无害化处理炉，建立了炉内流动、传热传质和燃烧的数值模型．利用Fluent软件对设计工况下的烧结炉进行数值模拟，采用多孔介质模型来计算炉内气体流动和压强分布，采用缩核模型来描述炉内物料的燃烧反应过程，得到了炉内气流速度场、温度场、气体组分分布以及烧结物料的温度分布．结果表明：鼓风进入风口0．2m后，速度变化平缓且分布较为均匀；物料的燃烧反应主要发生在风口中心线以上0．3～0．55m的区域内，物料下行至风口中心截面时已经燃烧完全；当掺煤量为12％、物料直径为16mm、过量空气系数为1．2时，炉内物料的温度为1138～1400K，完全可以满足无害化烧结工艺的要求．

Numerical Simulation on Fixed-bed Sintering of Fly Ash from Municipal Solid Waste Incinerators

To achieve sintering harmless treatment of fly ash from a municipal solid waste incinerator （MSWI）, numerical models were set up for the in-furnace gas flow, heat and mass transfer as well as the combustion process. The sintering process was numerically simulated using Fluent software under design conditions, during which the gas flow and pressure distribution were calculated using porous media model, while the material combustion process described using shrinking core model, following which the gas ve- locity field, gas and material temperature field as well as the gas composition distribution were obtained. Results show that in the area 0.2 m away from the tuyere, the speed of blowing air gets stable and be- comes evenly distributed; the material combustion mainly happens in the zone 0.3-0.55 m above the center line of tuyere; when the material falls down the center section of tuyere, the combustion process is already completed~ for a coal mixing ratio of 12%, pellet diameter of 16mm and an excess air coefficient of 1.2, the material temperature may reach 1 138-1 400 K, which can fully meet the requirement of sintering harm- less treatment of MWSI fly ash.