摘要
热应力过大是造成气化炉耐火衬里损坏的重要原因之一,分析耐火衬里的温度分布和应力分布能有效避免应力集中并优化耐火衬里结构。建立了三维多喷嘴对置式(OMB)水煤浆(CWS)气化炉炉壁K砖部位的计算模型,采用有限元法研究了稳态过程中热负荷对耐火衬里和钢壳的温度、等效应力、等效应变和总变形分布的影响。结果表明:热面砖热端面温度为1300℃时,计算的钢壳温度为206.4℃,该模拟结果与工业数据基本一致;热面砖应力>背衬砖应力>钢壳应力>隔热砖应力,且热面砖热端面应力最大易出现裂纹,陶瓷纤维处应变最大,隔热砖绝对变形量远小于热面砖和背衬砖;随着热面砖热端面温度从1100℃升高到1400℃时,耐火衬里和钢壳的整体温度升高,钢壳外表面温度从177.2℃逐渐增加到220.9℃,温度变化不超过50℃,耐火衬里及钢壳整体应力增大,尤其是热面砖应力增加最为明显,热端面应力从0.68 GPa升高到1.10 GPa,等效应变也逐渐增加,且热面砖和背衬砖应变增加幅度较大,热面砖、背衬砖和隔热砖的绝对变形量也随之增加;随着热面砖厚度由60 mm增加到230 mm,耐火衬里和钢壳的整体温度降低,钢壳外表面温度从225.9℃缓慢降低到206.4℃,即热面砖厚度对钢壳外表面温度影响较小,热面砖和背衬砖应力迅速减小而隔热砖和钢壳应力变化较小,当热面砖厚度为180 mm时,热面砖整体应力大小适中,而且分布均匀没有明显突变,耐火衬里的应变逐渐减小尤其是背衬砖区域应变减小趋势最快,而且应变结果与应力结果的变化规律基本一致,背衬砖绝对变形量最大,热面砖绝对变形量次之,隔热砖绝对变形量最小。结合温度场、应力、应变分布规律,当热面砖厚度为180 mm时,最有利于提高耐火衬里尤其是热面砖的使用寿命。
The excessive thermal stress is one of the most important factors for the damage of the refractory lining in the gasifier.Analysis of temperature distribution and stress distribution of refractory lining can effectively avoid the stress concentration and optimize the structure of refractory lining.The three-dimensional numerical model of K-brick of the industrial opposed multi-burner(OMB)coal-water slurry(CWS)entrained flow gasifier is established,and the effects of heat load on the temperature,equivalent stress,equivalent elastic strain and total deformation distribution of refractory lining and steel shell during steady state are studied by finite element method(FEM).When the end face temperature of the hot-face brick is 1300℃,the temperature of the steel shell is calculated to be 206.4℃,and the simulation results are well consistent with the industrial data.The equivalent stress of various linings follows the order:hot-face brick>backup brick>steel shell>heat isolation brick.The equivalent elastic strain of the ceramic fiber is the largest.The absolute deformation of heat isolation brick is much smaller than that of hot-face brick and backup brick.With the increases of the end face temperatures of hot-face brick from 1100℃to 1400℃,the overall temperatures of refractory lining and steel shell increase.The external surface temperature of the steel shell increases gradually from 177.2℃to 220.9℃,and the temperature change does not exceed 50℃.The overall equivalent stress of refractory lining and steel shell increase.The equivalent stress also increases,especially for hot-face brick,the enhancement of stress is the biggest,and the equivalent stress of the end face of hot-face brick increases from 0.68 GPa to 1.10 GPa.The equivalent elastic strain increases gradually and the strain of the hot-face brick and backup brick increases more greatly than that of heat isolation brick.The absolute deformation of the hot-face brick,backup brick and heat isolation brick also increase.As the thickness of hot-face brick increases from 60 mm to 230 mm,the overall temperatures of refractory lining and steel shell are decreased.The external surface temperature of steel shell decreases slowly from 225.9℃to 206.4℃,and it can be seen that the thickness of hot-face brick has little effect on the surface temperature of steel shell.The equivalent stress of hot-face brick and backup brick decreases rapidly while the stress of heat isolation brick and steel shell is only reduced a little.When the thickness of the hot-face brick is 180 mm,the overall stress of the hot-face brick is moderate,and the distribution is uniform without obvious mutation.The equivalent elastic strain of refractory lining decreases gradually,and the declining trend of strain in the region of backup brick is the fastest,and the strain result is consistent with the stress result.The absolute deformation of various linings follows the order:backup brick>hot-face brick>heat isolation brick.Combined with the results of temperature field,equivalent stress and equivalent elastic strain,it is proposed that the structure of hot-face brick is optimal when the thickness of hot-face brick is 180 mm,which is most conducive to improving the service life of hot-face brick and refractory lining.
作者
苏暐光
史雨晨
宋旭东
王文鑫
王焦飞
白永辉
姚敏
于广锁
SU Weiguang;SHI Yuchen;SONG Xudong;WANG Wenxin;WANG Jiaofei;BAI Yonghui;YAO Min;YU Guangsuo(State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering,Ningxia University,Yinchuan 750021,China;College of Chemistry and Chemical Engineering,Ningxia University,Yinchuan 750021,China;Chinese Energy Ningxia Coal Industry Co.,Ltd.,Yinchuan 750001,China;Institute of Clean Coal Technology,East China University of Science and Technology,Shanghai 200237,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2021年第1期274-283,共10页
Journal of China Coal Society
基金
宁夏重大研发计划资助项目(2019BCH01001)
国家自然科学基金资助项目(21463018)
2017年宁夏回族自治区重点研发资助项目(西部之光,201709)。
关键词
OMB气化炉
耐火衬里
K砖
温度场
等效应力
有限元法
OMB gasifier
refractory lining
K-brick
temperature field
equivalent stress
finite element method
