采用欧拉-拉格朗日法对生物质颗粒群在提升管内流动与分布特性方面展开研究。根据生物质颗粒结构特征建立链状可弯曲三维颗粒模型,考察表观气速（5.71、6.89、7.58、9.10 m/s）、颗粒质量流量（0.018、0.0216、0.0259、0.0311 kg/s）对丝状颗粒在提升管内轴向和径向分布特性的影响。研究发现：丝状颗粒在提升管轴向呈下密上疏的分布规律,在径向上随高度的增加颗粒分布由不均匀的倒C形分布向ω形转变。随着表观气速的增加,颗粒体积分数沿提升管径向逐渐降低。当表观气速ug=9.10 m/s时,颗粒处于快速流化状态,气固间相互作用增强、混合良好,沿提升管轴向分布更均匀。当颗粒质量流量增加,丝状颗粒聚集区域向上延伸,颗粒体积分数沿径向升高,且各水平截面的分布特征沿轴向差别不大。
Abstract
Euler-Lagrange method is adopted to study the flow and distribution characteristics of the filamentous biomass particles in the fluidized riser. According to the structural characteristics of filamentous biomass particles, a chain bendable three-dimensional particle model is established, and the effects of superficial gas velocity （5.71, 6.89, 7.85 and 9.10 m/s）,particles mass flow （0.018, 0.0216, 0.0259, 0.0311 kg/s） on the axial and radial distribution characteristics of particles were investigated. The results indicate that the filamentous biomass particles exhibit a distribution law of dense lower and upper sparse in the axial direction of the riser, and the particle distribution changes from a non-uniform inverted C-shaped to an ω distribution with the increasing height in the radial direction. When the superficial gas velocity ug=9.10m/s, the filamentous biomass particles stay in a fast fluidization state. The interaction between the gas and solid is enhanced, and well mixed. Additionally, the filamentous biomass particles are evenly distributed along the axial direction of the fluidized riser. With the increase of the mass flow rate of particles, the aggregated area of filamentous biomass particles extends upward. The volume fraction of particles increases along the radial direction as well, and the distribution characteristics of each horizontal cross-sections have slight difference along the axial direction.
关键词
生物质 /
计算流体力学 /
流化床 /
气固两相流 /
丝状颗粒
Key words
biomass /
computational fluid dynamics /
fluidized beds /
gas solid two-phase flow /
filamentous particles
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基金
国家自然科学基金青年项目（51906092）
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