大容量燃煤锅炉性能与氮氧化物排放浓度试验研究

测量了7台不同炉型和燃烧器型式的600 MW、660 MW机组燃煤锅炉性能和NOx排放浓度,分析了锅炉结构和燃烧器型式对锅炉性能、NOx排放浓度的影响。数据分析表明,锅炉性能和NOx排放浓度与锅炉结构和燃烧器型式关系密切。大容量机组燃煤锅炉燃烧效率都比较高,但其NOx排放浓度差别很大。W型火焰锅炉燃烧贫煤燃烧温度高,过量空气系数大,其NOx排放浓度最高;燃用高挥发分烟煤的四角切圆燃烧锅炉NOx排放浓度最低;其它机组,采用不同的燃烧器型式和低NOx燃烧技术,燃烧的煤种也不同,锅炉NOx排放浓度介于两者之间,但差别很大。煤种变化、锅炉运行参数变化对锅炉性能和实际NOx排放浓度都有较大影响。

Experimental Study on Performance and NOx Emission of Large Coal-fired Boilers

Influences of boiler structure and burner type on boiler performance and NO_x emission are being analyzed based on a series of tests on 7 boilers(600 MW,660 MW) with different structures and burner types.Results show that boiler performance and NO_x emission have close relationship with boiler structure and burner type.Among all the coal-fired boilers tested,the ones for large power units have relatively high combustion efficiencies and been(able) to achieve relevant design values,but their NO_x emissions vary a lot.The W-shape flame boiler produces the highest NO_x emission due to the high combustion temperature and large excess air ratio resulted by burning lean coal;while the tangential firing boiler,which burn bituminous coal of high volatile content,produces the lowest NO_x emission.NO_x emission of other boilers,which adopt different structures, burner types and apply different technologies for reducing NO_x emission,lies between the highest and lowest limit and differs a lot.That means,the coal category and boiler operation parameter exert great influence on boiler performance and NO_x emission.