Yang Yao Bin, Sharifi Vida N, Swithenbank Jim
Sheffield University Waste Incineration Centre (SUWIC), Department of Chemical and Process Engineering, Sheffield University, Mappin Street, Sheffield S1 3JD, UK.
Waste Manag. 2007;27(5):645-55. doi: 10.1016/j.wasman.2006.03.014. Epub 2006 May 26.
Waste incineration is a politically sensitive issue in the UK. The major current technology is based on direct combustion of wastes in a moving-grate furnace. However, general public opinion prefers non-direct burning technologies. Waste gasification is one of those nearest technologies available. By reducing the primary air-flow rate through the grate of a packed-bed system, operation of the existing solid-waste incineration equipment can be easily converted from combustion mode to gasification mode without major modification of the hardware. The potential advantages of this are lower dust carry-over in the flue gases, lower bed temperature (and therefore lower NO(x) formation in the bed), simplified gas-treatment procedures and lower running cost, among other benefits. The major disadvantages are, however, reduced throughput of the wastes and possibly higher carbon in the ash at exit. In this study, numerical simulation of both combustion and gasification of municipal solid wastes in a full-scale moving grate furnace is carried out employing advanced mathematical models. Burning characteristics, including burning rate, gas composition, temperature and burning efficiency as a function of operating parameters are investigated. Detailed comparisons between the combustion mode and gasification mode are made. The study helps to explore new incineration technology and optimise furnace operating conditions.
在英国，垃圾焚烧是一个政治敏感问题。当前的主要技术是基于在移动炉排炉中直接燃烧垃圾。然而，公众舆论更倾向于非直接燃烧技术。垃圾气化是现有的最接近的技术之一。通过降低通过固定床系统炉排的一次空气流速，现有固体废物焚烧设备的运行可以很容易地从燃烧模式转换为气化模式，而无需对硬件进行重大改造。这样做的潜在优势包括烟气中携带的粉尘减少、床层温度降低（因此床层中形成的氮氧化物也减少）、简化气体处理程序以及降低运行成本等。然而，主要缺点是垃圾处理量减少，并且出口灰中的碳含量可能更高。在本研究中，采用先进的数学模型对全尺寸移动炉排炉中城市固体废物的燃烧和气化进行了数值模拟。研究了燃烧特性，包括燃烧速率、气体成分、温度以及作为运行参数函数的燃烧效率。对燃烧模式和气化模式进行了详细比较。该研究有助于探索新的焚烧技术并优化炉内运行条件。
