摘要
以某台600MW亚临界锅炉为例,分析了低氮改造对其汽温静态特性和动态特性的影响.结果表明:低氮改造后炉内温度场、受热面结渣情况和锅炉运行模式均发生较大变化,对锅炉汽温特性产生较大影响;高负荷时锅炉汽温主要受分级燃烧导致的炉膛出口烟气温度上升和受热面结渣改善导致的炉膛出口烟气温度下降的综合影响;低负荷时锅炉汽温主要受分级燃烧导致的炉膛火焰中心高度降低和炉膛出口氧量的影响;快速降负荷过程中,炉膛火焰中心高度降低与汽轮机高压缸排汽温度下降对再热汽温的叠加影响是导致再热汽温易超跌的主要原因.
Taking a 600 MW subcritical boiler as an example, the static and dynamic characteristics of steam temperature were analyzed after low-NOx retrofit. Results show that great changes have taken place in the boiler after low-NOx retrofit, such as the in-furnace temperature field, the heating surface slagging and the boiler operation mode, which would significantly affect the steam temperature characteristics. Un- der high load conditions, the boiler steam temperature is mainly subjected to the combined effects of both furnace outlet gas temperature rise and drop respectively caused by air staging combustion and alleviated heating surface slagging~ whereas under low load conditions, the steam tempeature is mainly influenced by the lowered furnace flame center due to air staging combustion and by the outlet oxygen concentration. During unloading process of boiler, the rapid decline of reheat steam temperture is caused by both the low- ering of furnace flame center and the dropping of exhaust steam temperature in high-pressure cylinder of steam turbines.
出处
《动力工程学报》
CAS
CSCD
北大核心
2015年第9期699-703,共5页
Journal of Chinese Society of Power Engineering
基金
国家科技支撑计划资助项目(2015BAA05B02)
关键词
电站锅炉
低氮改造
汽温特性
炉膛火焰中心高度
负荷变化
utility boiler
low-NOx retrofit
steam temperature characteristic
furnace flame center~ loadchange
