为了研究某350 MW前后墙对冲燃烧煤粉锅炉经低氮燃烧技术改造后炉膛水冷壁出现的腐蚀结焦问题，利用ANSYS FLUENT软件对炉膛内的燃烧状况进行了数值模拟研究。结果表明：水冷壁附近的还原性气体（CO+H2S）的体积分数过高，约20.85%，是造成腐蚀、结焦问题的主要原因；分配调整燃尽风（OFA）风量和低氮燃烧器二次风风量，不能降低水冷壁附近还原性气体的体积分数；在保证现有运行工况不变的情况下，额外增加贴壁风口，贴壁风量为18.67 kg/s，在原腐蚀、结焦区附近形成空气保护层，能够有效地降低水冷壁附近还原性气体的体积分数至7.83%，从而有效地解决炉膛水冷壁的腐蚀、结焦问题。

In order to investigate the problem of serious corrosion and coking of water wall of a 350 MW opposite firing boiler transformed with new low NOx burners,numerical simulation with ANSYS Fluent was employed to study the combustion process inside the boiler.The simulation shows that the reductive environment (CO+H2S) is the main reason for corrosion and coking,and the concentration of the reductive gas is about 20.85% for the volume fraction.Fine tune of the over fire air flow and secondary air flow of the low NOx burner cannot decrease the concentration of the reductive gases near the water wall.Installing air inlet close to the wall can introduce addition air flow on the surface of the water wall,approximately 18.67 kg/s,which effectively decreases the concentration of the reductive gases to 7.83% for the volume fraction and eventually reduces the corrosion and coking of the water wall.

TK224.9

华能国际电力股份有限公司丹东电厂科技资金（HN-4620-201700126-JSQT00003）