切向燃烧煤粉锅炉二次风系统气体飞灰颗粒流动特性研究  

Study on Air-Fly Ash Particles Flow Characteristics in Secondary Air System of Tangentially Fired Pulverized Coal Boiler

作　　者：刘兴 袁东辉 付喜亮 刘贵喜 孟浩 赵凯 孙利 LIU Xing;YUAN Donghui;FU Xiliang;LIU Guixi;MENG Hao;ZHAO Kai;SUN Li(Inner Mongolia Jingneng Shengle Thermal Power Co.,Ltd.,Huhhot 011517,China;Inner Mongolia Electric Power Research Institute Branch,Inner Monglia ElectricPower(Group)Co.,Ltd.,Huhhot 010020,China)

机构地区：[1]内蒙古京能盛乐热电有限公司,内蒙古呼和浩特011517 [2]内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司,内蒙古呼和浩特010020

出　　处：《锅炉技术》2024年第2期15-19,31,共6页Boiler Technology

基　　金：内蒙古电力科学研究院项目(510241210023)。

摘　　要：二次风系统是煤粉锅炉燃烧系统的重要组成部分,气体中携带的飞灰颗粒在二次风系统内沉积将影响气体流动特性,严重时还会影响锅炉安全运行。以某350 MW超临界四角切圆煤粉锅炉的二次风系统为研究对象,采用数值模拟方法计算并分析了气体飞灰颗粒流动特性。计算结果表明:在均等配风方式的二次风门开度条件下,中间4层辅助风的速度基本相同,3层分离燃尽风(SOFA)风量占二次风总量的38.4%;各二次风门开度不变时,二次风入口速度变化对各燃烧器喷嘴风量分配影响不大。由于重力作用,飞灰颗粒进入大风箱后会向下流动,颗粒越大趋势越明显;AA层辅助风的含灰量较大,喷嘴出口附近的水冷壁较容易磨损;飞灰颗粒容易在2、3号角大风箱底部沉积,需要在底部合理设计排灰管。The secondary air system is an important part of the combustion system of pulverized coal boiler.The deposition of fly ash particles carried in the air of the secondary air system will affect the air flow characteristics,and even affect the safe operation of the boiler.In this paper,the secondary air system of a 350 MW supercritical tangentially fired pulverized coal boiler is taken as the research object,and the air-fly ash particle flow characteristics are calculated and analyzed by numerical simulation.The calculation results show that under the condition of equal air distribution mode of secondary air baffle opening,the auxiliary air velocities of the middle four layers are basically the same,and the air flow rate of the SOFA of the three layers accounts for 38.4%of the total secondary air.When the opening of each secondary air baffle is unchanged,the change of the secondary air inlet velocity(secondary flow rate)has little influence on the air flow rate distribution of each burner nozzle.Due to gravity,the fly ash particles flow downward after entering the windbox,and the larger the particles are,the more obvious the trend is.The ash content of auxiliary air in layer AA is large,so the water wall near this nozzle outlet is easy to wear.Fly ash particles are easy to deposit at the windbox bottoms of No.2 and 3 corners,so it is necessary to design ash discharge pipe reasonably at the bottom.

关 键 词：四角切圆燃烧 二次风管道 大风箱 飞灰颗粒 沉积 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]