四角切圆锅炉防高温腐蚀的燃烧优化试验研究

Experimental Study on Combustion Adjustment of a Tangentially-fired Boiler Against High-temperature Corrosion

为了降低贴壁水冷壁H2S体积分数,达到缓解水冷壁高温腐蚀的目的,对300 MW四角切圆锅炉进行了贴壁烟气成分测试及原因分析。结果表明:水冷壁的高温腐蚀主要集中在燃尽风以下的燃烧器区域,且沿着水冷壁中心线呈非对称分布,水冷壁中心线靠右区域的H2S体积分数偏高,造成这种现象的原因是配风不合理,二次风的刚性不足,无法完全包住一次风,使得火焰热扩散到水冷壁上所致;采取调整总风量、周界风量及强化一次风着火的措施后,贴壁H2S体积分数大幅度降低,水冷壁的高温腐蚀得到有效缓解。

To reduce the closing-to-wall H2S concentration to achieve the purpose of alleviating the high-temperature corrosion over the water wall, the closing-to-wall gas composition was measured for a 300 MW tangentially-fired boiler, while an analysis was conducted on the causes. Results show that the high-temperature corrosion is mainly concentrated on the water wall in the burner area below the overfire air, asymmetrically distributed along the center line of the water wall, with relatively high H2S concentration on the right of the center line, resulted from unreasonable air distribution, due to insufficient rigidity of the secondary air, which can not wrap up the primary air completely, leading to flame spreading to the water wall. The closing-to-wall H2S concentration has been significantly reduced, while the high-temperature corrosion has been effectively controlled, after taking the following measures, such as adjusting the total air volume and the surrounding air flow rate, and intensifying the combustion in primary air environment, etc.