四角风粉偏差对烟道烟温分布偏差的影响研究

EXPLORATION FOR WAYS TO RESOLVE PROBLEMS, NAMELY DEVIATION OF AIR-FUEL MIXTURE AT FOUR CORNERS, DEVIATION OF FLUE GAS TEMPERATURE DISTRIBUTION IN FLUE DUCT, AND LOCALIZED TUBE-WALL OVERTEMPE- RATURE ON HIGH TEMPERATURE CONVECTIVE HEATING SURFACE

切圆燃烧锅炉烟道烟温分布偏差及由此引发的高温对流受热面管壁局部超温问题,对锅炉的安全经济运行影响较大。引起烟道烟温分布偏差的原因除主烟气流的“残余旋转”外,四角风粉偏差也是不可忽视的重要因素。因此,对于高温对流受热面管壁超温问题,除采用提高受热面材质水平、部分燃烧器反切、蒸汽侧导汽管交叉等技术措施外,还可以通过各个角一次风粉、三次风粉、二次风量等调整改变锅炉四角风粉偏差来进行缓解或解决,而且该方法可能更为直接和有效。

Deviation of flue gas temperature distribution in the flue duct of tangential firing boiler, and problem of localized tube-wall overtemperature of high temperature convective heating surface resulted from this deviation, have comparatively large infuence upon safe and economic operation of the boiler. The causes leading to deviation of flue gas temperature distribution in the flue duct, excepting “residual whirling” of the main flue gas flow, the deviation of air-fuel mixture at four corners is also a very important factor which cannot be ignored. Hence, at the time to resolve the problem of localized tube-wall overtemperature on high temperature convective heating surface, the technical measures shouldn't be limited to such ways as enhancing the quality level of tube material, adopting counter-tangential firing for several burners, and crossing-over of steam conduit tube on the steam side, the said over temperature problem can also be finally relaxed or resolved through adjusting primary air-fuel mixture, tertiary air-fuel mixture, and the secondary air flow rate, to improve the deviation of air-fuel mixture at four corners for the boiler with tangential firing.