基于分区气化模型的MSW燃烧过程模拟研究  

Simulation study on MSW combustion based on zoning gasification model

作　　者：王汝佩 黄群星[1] 李文娟[1] 池涌[1] 严建华[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,杭州310027

出　　处：《环境工程学报》2016年第6期3185-3192,共8页Chinese Journal of Environmental Engineering

基　　金：国家重点基础研究发展计划项目(973计划)(2011CB201506);环保公益性行业科研专项(201509013)

摘　　要：针对一种新型两段式生活垃圾分区气化燃烧装置,提出了基于分区气化模型的垃圾热转化过程数值模拟方法。该方法耦合化学反应动力学和流体动力学软件预测移动床层垃圾的气化以及炉内气相空间的燃烧过程。通过对组分及热值差异较大的2种生活垃圾在炉内的反应过程进行模拟,得到了炉内的气相组分、温度及流场的分布。结果表明,该方法能够很好地适用于复杂组分的垃圾热转化过程模拟研究。高水分、低热值的生活垃圾气化后再燃炉膛出口温度处于973～1 073 K,不利于二恶英的生成控制。前拱二次风的增加不仅加强了炉内的湍流扰动,而且加强了炉内主反应区的温度。经过对流场和温度场进行优化,烟气的停留时间延长,炉膛出口烟气中的可燃气体组分大大降低,而且NO的浓度降低了近一个数量级。A numerical simulation method based on the zoning gasification model was presented for a thermal conversion process for waste in a new two-stage zoning gasified-combustion device. The method,coupled with software for chemical reaction kinetics and hydromechanics,was used to predict the gasification and combustion processes of municipal solid waste（ MSW） in a moving bed and gas space furnace,respectively. The reactions of two kinds of wastes with different components and lower heat values were simulated and the gas component distributions,temperatures,and flow fields in the furnace were obtained. The results show that this method is well suited to simulating the thermal conversion of MSW with complex components. For waste with a high moisture content and lower heat value,the furnace exit temperature is in the 973 to 1 073 K range,which is not conducive to the control of dioxin. The addition of secondary air from the front arch not only enhances the turbulence in the furnace,but also increases the temperature of the main reaction zone. Because of the optimization of the flow field and temperature distribution,the concentration of combustible gas significantly decreases due to the prolonged residence time of flue gas,and the mass fraction of NO is reduced by one order of magnitude compared to that without secondary air from the front arch.

关 键 词：分区气化 控氧热转化 反应动力学 自由焓最小化 

分 类 号：X705[环境科学与工程—环境工程]