Improved NOx emissions and combustion characteristics for a retrofitted down-fired 300-MWe utility boiler.
Improved NOx emissions and combustion characteristics for a retrofitted down-fired 300-MWe utility boiler.
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DOI：
10.1021/es1002378
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发表时间：
2010-05
影响因子：
11.4
通讯作者：
Zhengqi Li;Feng Ren;Zhichao Chen;Guangkui Liu;Zhenxing Xu
中科院分区：
文献类型：
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作者：
Zhengqi Li;Feng Ren;Zhichao Chen;Guangkui Liu;Zhenxing Xu
在300 MWe的下燃式锅炉上采用了一种高锅炉效率和低NO（x）排放相结合的新技术，作为燃烧低挥发分煤的下燃式锅炉降低NO（x）排放的经济手段。在改造后的锅炉上进行了试验，测量了一次风和煤粉混合气流沿着方向及炉内的烟温分布，炉膛沿着主轴方向的温度以及近壁区的O（2）、CO和NO（x）等气体浓度。通过与改造前的数据对比，验证了采用组合技术后，炉内烟温分布更加合理。峰值温度从上炉到下炉降低，火焰稳定性提高。尽管燃烧低挥发性煤，但NO（x）排放量可降低50%，而不会增加飞灰中未燃烧碳的含量，也不会降低锅炉的热效率。
A new technique combining high boiler efficiency and low-NO(x) emissions was employed in a 300MWe down-fired boiler as an economical means to reduce NO(x) emissions in down-fired boilers burning low-volatile coals. Experiments were conducted on this boiler after the retrofit with measurements taken of gas temperature distributions along the primary air and coal mixture flows and in the furnace, furnace temperatures along the main axis and gas concentrations such as O(2), CO and NO(x) in the near-wall region. Data were compared with those obtained before the retrofit and verified that by applying the combined technique, gas temperature distributions in the furnace become more reasonable. Peak temperatures were lowered from the upper furnace to the lower furnace and flame stability was improved. Despite burning low-volatile coals, NO(x) emissions can be lowered by as much as 50% without increasing the levels of unburnt carbon in fly ash and reducing boiler thermal efficiency.