350 MW超临界墙式切圆锅炉低负荷燃烧系统优化

Optimization of Low Load Combustion System for 350 MW Supercritical Wall Tangential Boiler

针对国内某电厂配置墙式切圆燃烧系统锅炉在低负荷情况下水冷壁壁温偏差大、局部水冷壁超温的现象,通过数值模拟对其产生的原因进行分析,发现锅炉一次风切圆偏大是导致其发生的主要原因;对此,分析对比了增设喷口导流片和燃烧器整体偏置一定角度2种缩小燃烧切圆的方案,结果表明:通过燃烧器整体偏置一定角度的方案切实可行,且效果理想,最终通过数值模拟对燃烧器偏置一定角度的方案进行计算,对比优化前后炉内假想切圆温度场、流场分布情况,验证了该方案的合理性。

Aiming at the phenomenon of large water wall temperature deviation and local water wall over temperature of a domestic power plant boiler equipped with wall tangential combustion system under low load,the causes are analyzed by numerical simulation,and it is found that the large primary air tangential circle of the boiler is the main cause;in this regard,the paper analyzes and compares two schemes of reducing the tangency of combustion,which are adding the nozzle guide vane and offsetting the burner with a certain angle.The results show that the scheme of offsetting the burner with a certain angle is feasible and the effect is ideal.Finally,the scheme of offsetting the burner with a certain angle is calculated by numerical simulation,and the temperature field of the furnace before and after optimization is compared.The flow field distribution verifies the rationality of the scheme.