空气分级燃烧炉内壁面硫化物分布的数值模拟

Numerical Simulation of Sulfide Distribution on Furnace Walls with Air-staged Combustion

以某600 MW超超临界锅炉为研究对象,采用数值模拟方法研究了硫化物气体在炉内还原区水冷壁壁面区域的分布特性.结果表明:SO_2主要分布在主燃烧器壁面区域,而H_2S主要分布在分离燃尽风(SOFA)与主燃烧器之间的壁面区域,且该区域的氧量极低,温度又较高,发生高温腐蚀的可能性更大;随着燃料中含硫量的增大,壁面区域的硫化物气体质量分数有所提高,但并不显著,而高质量分数硫化物气体所占区域面积却明显增大,在主燃烧器的局部区域,壁面也出现了H_2S质量分数较高的区域.

Taking a 600 MW ultra-supercritical boiler as an object of study, numerical simulation was conducted to study the distribution characteristics of sulfide gases around water walls in the furnace. Results show that SO2 mainly appears in the region near main burners, while H2S mainly distributes in the region between separated over fire air （SOFA） region and the main burners, where high-temperature corrosion is easy to occur due to the very low concentration of oxygen and the high-temperature atmosphere. With the rise of sulfur content in fuel, the concentration of sulfide gases is slightly increased around the water wall, but the occupation area of high-concentration sulfide gases is significantly enlarged, and high concentration of H2 S even occurs in local regions of the water wall near main burners.