300 MW 机组烟煤锅炉防结焦改造

摘要

Serious slagging occurred in a 300 MW unit firing easy﹣slagging low quality bituminous coal. Thus,retrofitting scheme that shrinking tangential circle diameter of the secondary air and reduce the gas flow swirling intensity was put forward.Moreover,numerical simulation was carried out to investigate the combustion process before and after the transformation.Analysis on velocity field,coal particle trajectory, temperature field and O2/CO concentration field shows the slagging in furnace was improved dramatically and the combustion stability was enhanced.Half﹣year operation on this unit verified the rationality of this retrofit scheme.%针对某电厂300 MW 机组燃用易结焦劣质烟煤出现较严重的结焦问题，提出了将二次风切圆缩小、降低炉内气流旋转强度的改造方案，并采用数值模拟方法对改造前后炉内燃烧过程进行了研究。通过分析、比较改造前后炉内的速度场、煤粉颗粒轨迹、温度场、浓度场以及改造效果等，表明改造后炉内的结焦状况得到明显改善，锅炉的燃烧稳定性增强，经过半年的运行实践，验证了方案的合理性。