关键词: 固定床, 甲烷化反应器, 数值模拟, 有限元, 场分布, 计算流体力学

Abstract:

The temperature distribution has its influence directly on methane production and equipment safety of the fixed-bed methanation reactor. To research the adiabatic methanation reactor which can produce 1.275 billion cubic meters SNG a year, the three-dimensional entity model was set up. A gas-solid two-phase reactor model for chemical reactions, heat exchange and mass transfer in porous media was established by the software ANSYS-CFX. The internal profile of temperature, pressure and velocity field and the methane yield profile in the fixed-bed internal methanation reactor with double catalyst layers were obtained. Based on the finite element numerical simulation method, the characteristic field distributions of different bed structures were explored. The influence of the bed structure on each characteristic field profile was analyzed, and then, the structure optimization of the bed layer was determined. The structure of the end support extend model was more favorable of the temperature profile along the radial of the reactor and the improvement of the methane mass fraction. The entrance temperature, space velocity and entrance pressure were researched. Through the analysis of the parameters that influenced the degree of the reaction, the fluctuation ranges of the permitted entrance were put forward for this process.

Key words: fixed-bed, mathanation reactor, numerical simulation, finite element, field profile, CFD