摘要
为实现高效燃烧和低NOx排放,在一台1000MW对冲燃烧烟煤锅炉上进行燃烧优化调整试验,测量炉膛烟气温度分布,研究煤种、省煤器出口氧量、燃尽风量、燃烧器及燃尽风风门开度、燃烧器投运方式和负荷等因素对燃烧和NOx排放的影响规律。试验表明,省煤器出口氧量和燃尽风量对锅炉效率和NOx排放有较大影响,二者分别保持在3.0%和750t/h时运行效果较好,且利于消除屏式过热器结焦;调整同层燃烧器外二次风挡板开度可减轻沿炉膛宽度的氧量不均;燃用设计煤种、全关燃尽风喷口外二次风挡板、保持燃烧器中心风母管风门开度为50%并在满负荷时尽量停止一层上排燃烧器利于降低飞灰中碳的质量分数。调整后测得锅炉效率超过94.4%,NOx排放浓度低于300mg/m3,明显优于国内目前运行的锅炉。
For getting higher efficiency and lower NOx emission, a test to optimize combustion system is conducted in a 1 000 MW bituminous coal-fired boiler in opposed firing pattern. During the test, the gas temperature distribution in furnace is measured, combustion and NOx emission characteristic is studied by varying such factors as type of coal, O2 at economizer exit, mass flow of over fired air （OFA）, air damper position of burner and after air port （AAP）, combinations of burners and boiler load. It indicates that O2 at economizer exit and mass flow of OFA have great effect on boiler efficiency and NOx emission. It＇s better to keep these two parameters at 3.0% and 750 t/h respectively, which can also eliminate slagging on platen superheater. O2 deviation along furnace width can be eliminated by setting outer second air damper of burners in same horizontal row at different proper positions. Unburned carbon in fly ash can be decreased by using design coal, closing outer second air damper of AAP, setting burner＇s core air damper at 50% and shutting down one-layer upper row burners at full load if possible. After adjustment, the measured efficiency of boiler is above 94.4% and NOx emission concentration is lower than 300 mg/m^3. They are obviously better than those of boilers in service in China.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第4期105-110,共6页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划资助项目(863计划
2007AA04Z195)
关键词
超超临界
燃煤锅炉
对冲燃烧
氮氧化物排放
Ultra-supercritical Coal-fired boiler Opposed firing NOx emission
