DG 1900/25.4-Ⅱ4型煤粉锅炉炉内过程的数值模拟

Numerical Simulation on Flow and Combustion Process in the Furnace of a DG 1900/25.4-Ⅱ4 Coal-fired Boiler

为了预测煤A在DG 1900/25.4-Ⅱ4型600 MW、前后墙对冲燃烧锅炉炉内的燃烧性能及了解掺混煤B后对炉内燃烧的促进作用,对煤A及煤A和煤B的混煤的两相流动、燃烧过程及传热传质等特性进行了数值模拟,获得了煤粉在炉内燃烧时的流场、温度场、组分浓度场及着火距离等参数.结果表明:煤A在该型锅炉内的燃烧效果较差,炉内温度较低,火焰中心位置过高,煤粉着火距离过长;掺混煤B后可显著改善炉内燃烧效果,各燃烧参数均处于正常范围;掺混煤B的比例越高,燃烧效果越好.

To estimate the burning properties of coal A in the furnace of a 600 MW DG 1900/25.4-II4 coal-fired boiler,and study the influence of blending coal B to coal A on the burning properties,numerical simulation has been performed to the two-phase flow,combustion process and heat transfer characteristics of both coal A and the mixture of coal A and coal B,during which corresponding flow field,temperature field,component concentration field and ignition distance were obtained.Results show that coal A produces poor combustion effect in the boiler,with relatively low in-furnace temperature,high location of flame center and long distance of coal ignition;whereas when coal B is blended into coal A,the combustion effect is obviously improved,with various combustion parameters lying in normal scope;the higher the mass ratio of coal B being blended,the better the combustion effect will be obtained.