1 000 MW超超临界锅炉低NOx 燃烧技术改造及性能优化试验

为降低NO_x排放,某电厂对其1 000 MW超超临界锅炉进行了低NO_x燃烧技术改造。改造后锅炉NO_x排放质量浓度较改造前降低42%,但CO排放质量浓度、飞灰含碳质量分数较改造前均有上升。在分析改造前后锅炉燃烧工况变化的基础上进行了燃烧调整试验,通过改变省煤器出口O₂体积分数、二次风配风方式、OFA风量和SOFA风量,研究了不同工况下锅炉燃烧及NO_x排放特性。调整后锅炉在高负荷下CO排放质量浓度降至100 mg/m³以下,飞灰含碳质量分数降至1%以下。

Retrofit with Low NOx Combustion Technique and Performance Optimization Test for a 1000-MW Ultra Supercritical Boiler

The technical retrofit adopting low NO_x combustion technology was carried out for a 1 000-MW ultra supercritical boiler to reduce the NO_x emissions. After the retrofit, the NO_x emission mass concentration was down by 42%, while the CO emission mass concentration and the carbon content of fly ash were higher. Therefore, based on the analysis of the variation of the combustion conditions before and after the retrofit, the combustion adjustment test was conducted, in which the boiler combustion and NO_x emission characteristics under different working conditions were studied by changing the oxygen volumetric fraction at the economizer exit, the secondary air distribution mode, the OFA flow rate and the SOFA flow rate. The test results show that the CO emission mass concentration has been dropped to less than 100 mg/m³ and the carbon content of fly ash has been down below 1% under high boiler load after the combustion adjustment.