大型CFB锅炉天然气点火系统应用问题研究  

Study on Application of Natural Gas Ignition System in Large CFB Boiler

作　　者：郭学良 GUO Xueliang(Shanxi Century Pilot Electric Power Science and Technology Co.,Ltd.,Taiyuan 030006,China)

机构地区：[1]山西世纪中试电力科学技术有限公司,山西太原030006

出　　处：《锅炉技术》2023年第4期24-29,共6页Boiler Technology

摘　　要：针对大型循环流化床(CFB)锅炉应用天然气点火系统存在燃烧不稳定火焰脱火的问题,以某电厂350 MW超临界循环流化床机组天然气点火系统为研究对象,探讨了天然气层流扩散和紊流扩散燃烧的机理,从燃烧学理论出发研究了天然气火焰脱火的主要原因是燃烧器喷口燃气流速与火焰传播速度不匹配。基于一元定常可压缩气体流动的基本特性,将天然气燃烧器气枪喷口简化为一元流体的喷管,计算出CFB锅炉天然气点火系统燃烧器出口的最大流速,以此为基础提出天然气系统燃气压力的调整措施和燃烧器喷口结构的优化方案。通过理论分析计算和设备的结构优化,解决了大型CFB锅炉天然气点火系统燃烧器火焰脱火的问题,可为同类型的机组提供借鉴的依据。In order to solve the problem of unsteady combustion flame blow-off existing in the application of natural gas ignition system in large circulating fluidized bed(CFB)boilers,the natural gas ignition system of a 350 MW supercritical circulating fluidized bed unit in a power plant is studied in this paper.The mechanism of laminar and turbulent diffusion combustion of natural gas are discussed,and the main reason of natural gas flame blow-off is that the velocity of gas flow at the burner nozzle does not match with the velocity of flame propagation.Based on the basic characteristics of one-dimensional steady compressible gas flow,the nozzle of gas gun of natural gas burner is simplified as a nozzle of one-dimensional fluid,and the maximum flow velocity of burner outlet of natural gas ignition system of CFB boiler is calculated,on this basis,the adjustment measures of gas pressure in natural gas system and the optimization scheme of burner nozzle structure are put forward.Through theoretical analysis and calculation and structure optimization of equipment,the problem of flameout of burner in natural gas ignition system of large CFB boiler is solved,which can provide reference for similar units.

关 键 词：天然气 脱火 CFB 点火系统 紊流扩散燃烧 火焰传播速度 

分 类 号：TK227.7[动力工程及工程热物理—动力机械及工程]