某超超临界锅炉低NOX燃烧优化对高温腐蚀的影响

为了评估低NOX燃烧器升级后水冷壁高温腐蚀的可能性，对某超超临界锅炉炉内燃烧进行了数值模拟，并对SOFA上摆的燃烧优化工况做了水冷壁贴壁气氛测试。结果表明，主燃烧区的上部和COFA、SOFA之间的还原区发生高温腐蚀的可能性较大；SOFA上摆扩大了还原区，增加了高温腐蚀的可能性，还原区贴壁H2S平均浓度沿着炉膛高度的增加而升高，为180-400μl/L；SOFA摆角的偏差使得局部H2S浓度达到了800μl/L，进一步加剧了局部区域高温腐蚀的风险；强氧化⇌强还原交替变动，使得SOFA以上区域(43.3m-46.1m)的高温腐蚀风险较典型还原区更为严重。在锅炉实际运行中，应尽可能权衡降低NOX排放和控制高温腐蚀风险。

Influence of Low NOx Combustion Optimization on the High-temperature Corrosion for an Ultra-supercritical Boiler

In order to estimate the possibility of high-temperature corrosion of water-wall after upgrading the low NOx burner, the numerical simulation is carried out for an ultra-supercritical boiler and the pinning atmosphere is measured after increasing the angle of SOFA. The results show that the upper part of the main combustion zone and the reductive zone between OFA and SOFA are more likely to have the high-temperature corrosion. The reductive zone is increased due to the enlarged angle of over-fire air, resulting in a higher possibility of high-temperature corrosion near the water-wall. The average concentration of H2S near the water-wall increases along with the height of furnace, about 180-400ul/L. The risk of high-temperature is increased because of the deviation in SOFA; the largest concentration of H2S is 800ul/L, further increasing the risk of high-temperature corrosion due to the alternation of the pinning atmospheres from strong oxidation atmosphere to strong reductive atmosphere. In the actual operation of boiler, reducing NOx and controlling the risk of high-temperature corrosion should be balanced.