Abstract: Vacuum pressure swing adsorption (VPSA) for oxygen generation is a complicated dynamic process. Understanding the flow characteristics is essential for the design and improvement of radial flow adsorber. A two-dimensional radial flow adsorber model of VPSA for oxygen generation was established based on the Fluent porous medium model with user defined functions. The flow characteristics of the first and second cycle in radial flow adsorber were analyzed. The effects of particle diameter, the perforated-plate opening ratios and the cross section ratio of central channel to outer channel were discussed. The results showed that the flow distribution and adsorption efficiency of radial adsorber were affected by the volume of both the central channel and the outer channel, which needed to be carefully considered when designing. The concentration and recovery rate of oxygen can be increased when smaller particles were used, which also improved the flow distribution. The increase of the cross sectional area ratio of central channel and outer channel was beneficial to flow distribution. The radial non-uniformity of velocity reduced with the decrease of the perforated-plate opening ratio of the central channel and outer channel, and the influence of perforated-plate opening ratio of central channel was more significant than that of the outer channel.

Key words: radial flow adsorber, VPSA, air separation for oxygen generation, numerical simulation, CFD

摘要： 真空变压吸附制氧是一个复杂的动态过程，深入了解真空变压吸附制氧过程中吸附器内的流动特性是吸附器设计与完善的基础。基于Fluent中的多孔介质模型，通过用户自定义函数功能，建立了真空变压吸附制氧用径向流吸附器的二维轴对称模型，研究了真空变压吸附首次和第二次循环中径向流吸附器的流动特性，对比分析了吸附剂颗粒直径、流道截面积比和流道多孔板开孔率对吸附器流动特性的影响。结果表明，中心流道和外流道空间体积均会影响吸附器的流场分布和制氧效率，在设计径向流吸附器时需要兼顾内外流道空间体积的影响；减小吸附剂颗粒直径能改善吸附器气体分布状况，提高氧气分离浓度和回收率；增大中心流道与外流道截面积比有利于提升床层气体均布效果；中心流道和外流道多孔板开孔率减小均有利于降低床层径向速度不均匀性，中心流道多孔板开孔率的影响比外流道更大。

关键词: 径向流吸附器, 真空变压吸附, 空分制氧, 数值模拟, 计算流体力学