Methane steam reforming with packed bed is an important approach to get hydrogen in industrial production. Compared with the conventional packed bed, the grille-sphere composite packed bed has the advantages of lowering the pressure drop, increasing the uniformity of the radial temperature distribution and improving overall efficiency. In the present paper, the axial variable diameter particle structure of grille-sphere composite packed bed has been proposed, and four different structures are studied to compare their performances. Moreover, two simulation methods are used in study: (a) the solid particle method which can show details of the simulation, (b) the equivalent medium method which can show the macro situation of simulation. Through these two methods, performances of four structures in different parameters are compared and analyzed. It is found that the axial variable diameter particle structures have better performance than the typical structures in different parameters cases. Inlet temperature, inlet velocity and inlet steam-carbon ratio are set to parameters respectively in simulation. According to the simulations, higher inlet temperature and inlet steam-carbon ratio will facilitate the reactions, however, higher inlet velocity will hinder the reactions. Through the solid particle method, the reasons of better performance have been found, and two methods difference are also studied. Compared with typical structures, the specific axial variable diameter structure brings 4.5% higher outlet hydrogen mass flow and 5.2% higher outlet hydrogen selectivity. Analysis of this study can guide the design of packed beds in industrial production and the results of this study have significance in industrial hydrogen production.

填充床甲烷蒸汽重整是在工业生产中获得氢气的重要方法。与常规填充床相比，该格栅-球形复合填充床具有降低压降，增加径向温度分布均匀性和提高整体效率的优点。本文提出了格栅球复合填料床的轴向变径颗粒结构，并研究了四种不同的结构以比较其性能。此外，在研究中使用了两种模拟方法：（a）可以显示模拟细节的固体颗粒方法，（b）可以显示模拟宏观状况的等效介质方法。通过这两种方法，比较和分析了四种结构在不同参数下的性能。发现在不同参数情况下，轴向变径颗粒结构具有比典型结构更好的性能。在仿真中，分别将入口温度，入口速度和入口汽碳比设置为参数。根据模拟，较高的入口温度和入口蒸汽碳比将促进反应，但是，较高的入口速度将阻碍反应。通过固体颗粒法，找到了性能更好的原因，并研究了两种方法的区别。与典型结构相比，特定的轴向可变直径结构带来了4.5％的出口氢气质量流量和5.2％的出口氢气选择性更高。