Abstract Pulverized biomass has great potential to replace coal in many industrial systems such as suspension-firing furnaces and entrained-flow gasifiers. The shape of pulverized biomass deviates significantly from the quasi-spherical coal particle, however, it is common to simulate pulverized biomass particles as spheres as most biomass models are developed based on coal models. With the aim of obtaining a more realistic simulation of pulverized biomass, this work extends the treatment of pulverized biomass to spheroids. A spheroid model that accounts for spheroidal particle drag force and torque was implemented into an Eulerian-Lagrange computational fluid dynamic solver. Comprehensive verifications and validations were performed by comparing with experiments and direct numerical simulations. Furthermore, non-reactive simulations of a lab-scale entrained flow gasifier were carried out using a conventional spherical particle model, a simplified non-sphere model, and the implemented detailed spheroidal particle model. By studying the simulation results of particle and fluid velocities in axial, radial and tangential directions, differences were observed when comparing the sphere model, the simplified non-sphere model, and the spheroid model. The spheroid model shows that particle orientation, which is ignored in the sphere model and the simplified non-sphere model, plays a role in the behavior of the particle dynamics. It was also found that, under such conditions, the spheroid model, compared to the sphere model, yields a more dispersed distribution regarding the particle residence time and local concentration. These non-reactive simulation results imply that shortcomings may exist in the common practice of simulating conversion of pulverized biomass in which the sphere model or the simplified non-sphere model is applied.

中文翻译：

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使用球体粒子近似法对粉碎的生物质射流进行欧拉-拉格朗日模拟

摘要 粉碎的生物质在悬浮燃烧炉和气流式气化炉等许多工业系统中具有替代煤炭的巨大潜力。粉碎的生物质的形状与准球形煤颗粒有很大的偏差，但是，由于大多数生物质模型是基于煤模型开发的，因此通常将粉碎的生物质颗粒模拟为球体。为了获得更真实的粉碎生物质模拟，这项工作将粉碎生物质的处理扩展到球体。在欧拉-拉格朗日计算流体动力学求解器中实现了考虑球体粒子阻力和扭矩的球体模型。通过与实验和直接数值模拟的比较，进行了全面的验证和验证。此外，实验室规模的气流气化炉的非反应模拟是使用传统的球形颗粒模型、简化的非球形模型和实施的详细球形颗粒模型进行的。通过研究轴向、径向和切向方向的粒子和流体速度的模拟结果，在比较球体模型、简化的非球体模型和椭球体模型时观察到差异。球体模型表明，在球体模型和简化的非球体模型中被忽略的粒子取向在粒子动力学行为中起作用。还发现，在这种条件下，与球体模型相比，球体模型在粒子停留时间和局部浓度方面产生更分散的分布。