Fluidized bed gasification has proven to be an appropriate technique for converting various biomass feedstocks into helpful energy. Air distributor plate design is one of the critical factors affecting the thermochemical conversion performance of fluidized bed gasifiers. The present study is proposed to investigate the mixing pattern and pressure drop across different configurations of air distributors using a two-fluid model (TFM) of finite volume method-based solver Ansys FLUENT. Pressure drop across the bed and mixing pattern have been investigated through qualitative and quantitative analysis of CFD results using three diverse distributor plate designs: perforated plate, 90° slotted plate, and 45° swirling slotted plate. The pressure drop by employing the perforated distributor plate reveals the highest pressure drop due to the larger open area ratio. 90° slotted plate is 7% and 4% lesser than the perforated and 45° slotted plate, respectively. A smaller velocity head developed through the wider open area of the straight slotted plates. The distributor design configuration with a 45° slotted plate exhibits considerable pressure drop compared to a 90° slotted plate due to the longer path length of the slot. Numerical pressure drop results across the bed with different types of distributor plates prove reasonable agreement with the experimental results available in the literature. Mixing behavior in perforated distributor plates exhibits an initial volume fraction of around 0.58. However, it falls rapidly as go up the riser (7.7% of column height); 90° slotted plate shows an initial lower volume fraction of around 0.5. It exhibits an even broader range of sand volume fraction and column height (13.46% of column height). Finally, the 45° distributor plate reveals the highest range of volume fraction through the riser height (17.3% of column height), indicating the better mixing characteristics of the fluidized zone.

中文翻译：

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流化床气化器不同空气分布器设计的流体力学行为计算分析

流化床气化已被证明是将各种生物质原料转化为有用能源的合适技术。空气分布板设计是影响流化床气化器热化学转化性能的关键因素之一。本研究旨在使用基于有限体积法的求解器 Ansys FLUENT 的双流体模型 (TFM) 研究空气分配器不同配置的混合模式和压降。使用三种不同的分配板设计：多孔板、90° 开槽板和 45° 旋流开槽板，通过对 CFD 结果的定性和定量分析研究了床和混合模式的压降。由于较大的开口面积比，采用多孔分布板的压降显示出最高的压降。90° 开槽板分别比穿孔板和 45° 开槽板小 7% 和 4%。较小的速度头通过直槽板的较宽开口区域形成。由于狭缝的路径长度较长，因此与 90° 狭缝板相比，具有 45° 狭缝板的分配器设计配置表现出相当大的压降。具有不同类型分布板的床的数值压降结果证明与文献中可用的实验结果具有合理的一致性。多孔分布板中的混合行为表现出大约 0.58 的初始体积分数。但是，随着上升管上升（柱高的 7.7%），它迅速下降；90° 开槽板显示初始较低的体积分数约为 0.5。它表现出更广泛的砂体积分数和柱高（柱高的 13.46%）。最后，45° 分布板显示通过立管高度（塔高的 17.3%）的最高体积分数范围，表明流化区具有更好的混合特性。