摘要
为解决旋风分离器分离效率下降导致的细颗粒逃逸,锅炉床压下降,出口烟气温度低,出力不足等问题,对某300 MW级CFB锅炉中心筒进行优化改造,利用CFD方法验证中心筒优化后的分离器分离效率及其对锅炉运行效果的影响。通过增加中心筒插入深度减少颗粒逃逸,缩小中心筒直径并将缩口偏心布置,减少进入排气管的颗粒等对中心筒进行改造。CFD理论计算和现场飞灰粒径分布试验表明,中心筒结构优化后,分离器压降增加约370 Pa;分离器总分离效率提高了0. 54%,达到99. 45%,分离效果好,小颗粒比例较高。现场试验表明,中心筒改造后,床温平均降低20℃,炉膛上部差压增加0. 3 kPa。飞灰颗粒中位径由23μm降至12. 6μm,锅炉效率提高,尿素用量降低50%～70%。理论计算和现场试验表明,本次改造设计合理有效。
In order to solve the problems,i.e.,fine particles diffusion,pressure drop of boiler bed,low temperature of outlet flue gas and insufficient output,the vortex finder of a 300 MW CFB boiler was optimized and retrofitted.The separation efficiency of separator with vortex finder optimized and its influence on operation effect of boiler were verified by CFD method.The vortex finder was optimized by increasing the insertion depth of vortex finder to reduce the particle escape,reducing the diameter of vortex finder and eccentric layout of necking,lessen particles entering the exhaust pipe The CFD theoretical calculation and fly ash particle size distribution test show that the pressure drop of the separator increases by ca.370 Pa after optimizing the vortex finder shape,and the total separation efficiency of the separator increases to 99.45%,which Increases by 0.54%.The separation effect is good and the proportion of small particles is high.The average bed temperature decreases by 20 ℃ and the differential pressure of upper furnace increases by 0.3 kPa after retrofitting the vortex finder.The median diameter of fly ash particles decreases from 23 μm to 12.6 μm.The boiler efficiency is improved and the urea consumption is reduced by 50%-70%.The theoretical calculation and field test prove that the design is reasonable and effective.
作者
袁野
林伟荣
时正海
高洪培
孙献斌
肖平
YUAN Ye;LIN Weirong;SHI Zhenghai;GAO Hongpei;SUN Xianbin;XIAO Ping(Huaneng Clean Energy Research Institute,Beijing 102209,China)
出处
《洁净煤技术》
CAS
2018年第6期71-76,共6页
Clean Coal Technology
基金
中国华能集团科技项目(HNKJ16-H02)
关键词
旋风分离器
中心筒
分离效率
压降
SNCR
床温
gas cyclones
vortex finder
separation efficiency
pressure drop
SNCR
bed temperature
