Faculty of Maritime and Transportation , Ningbo University , Ningbo 315211 , P. R. China.
Environ Sci Technol. 2019 Oct 1;53(19):11597-11612. doi: 10.1021/acs.est.9b03872. Epub 2019 Sep 10.
A cascade-arch-firing low-NO and high-burnout configuration (CLHC) was proposed as a solution for the W-shaped flame furnace's incompatibility problem of strengthened low-NO combustion and high burnout. Numerical simulations verified by industrial-size measurements of a 600 MW W-shaped flame furnace were used to confirm the CLHC's low-NO and high-burnout characteristics and evaluate its cascade-arch configuration effect on the gas/particle flow, coal combustion, and NO formation. The furnace with the existing low-NO combustion art showed NO emissions of about 900 mg/m at 6% O and carbon in fly ash of about 5%. In applying CLHC as a replacement for the prior art, numerical simulations at typical cascade-arch configurations of = 1/5, 1/4, and 1/3 ( signifying the ratio of the lower arch depth to the total arch depth) showed that as increased, both the flow field and combustion symmetry initially improved but then deteriorated. In conjunction with the improvement in both NO emissions and burnout, the = 1/4 setting achieved the best furnace performance with NO emissions 707 mg/m at 6% O and carbon in fly ash of 5.5%. In comparison with the prior low-NO art, CLHC reduced further NO emissions by 22% and almost maintains the burnout rate.
一种串列拱火低 NOx 和高燃尽配置（CLHC）被提出作为解决 W 火焰炉强化低 NOx 燃烧和高燃尽之间不兼容问题的一种方法。利用工业规模的 600MW W 火焰炉的测量结果对数值模拟进行验证，以确认 CLHC 的低 NOx 和高燃尽特性，并评估其串列拱结构对气体/颗粒流动、煤粉燃烧和 NO 形成的影响。现有的低 NOx 燃烧技术在 6% O2 和飞灰含碳量为 5%时，NOx 排放量约为 900mg/m。在应用 CLHC 替代现有技术时，对 = 1/5、1/4 和 1/3 （表示下拱深度与总拱深度之比）的典型串列拱结构进行数值模拟表明，随着 的增加，流场和燃烧对称性最初得到改善，但随后恶化。在提高 NOx 排放和燃尽率的同时， = 1/4 的设置实现了最佳的炉膛性能，在 6% O2 和飞灰含碳量为 5.5%时，NOx 排放量为 707mg/m。与现有低 NOx 技术相比，CLHC 进一步降低了 22%的 NOx 排放，几乎保持了燃尽率。
