炼化废液焚烧飞灰粒子碰撞概率影响因素研究

发布时间：2018-11-22 09:55

【摘要】：利用CFD软件FLUENT对某石化企业废液焚烧余热锅炉内换热管壁上飞灰粒子碰撞及分布情况进行数值模拟研究。采用Eulerian-Largrangian法对余热锅炉内气-固两相流问题进行求解,重点分析粒子尺寸、烟气流速、纵向管间距、横向管间距等四种因素对飞灰粒子碰撞概率的影响情况。研究结果表明,除纵向管间距之外,其余三种因素对飞灰粒子的碰撞概率影响显著。飞灰粒子碰撞概率随粒子尺寸的增大而增大,其中大尺寸粒子主要在前两排换热管束的迎风侧发生碰撞,小尺寸粒子在迎风侧和背风侧均发生碰撞,且碰撞概率分布均匀。当烟气流速增大时,飞灰粒子碰撞概率随之增大,且20.0μm飞灰粒子比0.2μm飞灰粒子对烟气流速更为敏感。随着纵向管间距的增大,飞灰粒子碰撞概率仅出现轻微的下降趋势,而随着横向管间距的增大,飞灰粒子碰撞概率下降明显。
[Abstract]:The impact and distribution of fly ash particles on the heat transfer tube wall of waste liquid incineration boiler in a petrochemical enterprise were simulated by CFD software FLUENT. The Eulerian-Largrangian method is used to solve the gas-solid two-phase flow problem in a waste heat boiler. The effects of particle size, flue gas velocity, longitudinal tube spacing and transverse tube spacing on the collision probability of fly ash particles are analyzed. The results show that the impact probability of fly ash particles is significantly affected by the other three factors except the longitudinal tube spacing. The collision probability of fly ash particles increases with the increase of particle size, in which large particles collide mainly on the upwind side of the first two rows of heat transfer tube bundles, and small particles collide on both upwind and leeward sides, and the collision probability distribution is uniform. With the increase of flue gas velocity, the collision probability of fly ash particles increases, and 20.0 渭 m fly ash particles are more sensitive to flue gas velocity than 0.2 渭 m fly ash particles. With the increase of longitudinal tube spacing, the collision probability of fly ash particles only shows a slight downward trend, but with the increase of transverse tube spacing, the collision probability of fly ash particles decreases obviously.
【作者单位】：大连理工大学能源与动力学院;大连理工大学环境学院工业生态与环境工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(51406025)
【分类号】：X742;TQ021

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