球形吸附剂颗粒扩散方程的数值求解

Numerical Solution of Diffusion Equation of Spherical Particle of Absorbent

对于速率控制的变压吸附过程而言,吸附剂颗粒上的扩散方程求解十分关键.采用有限差分法数值求解扩散方程,分别利用等距网格和等体积网格划分计算区域.结果表明,当网格节点数较少时,等体积网格比等距网格具有更高的计算精度.当球形计算区域网格节点足够密时,节点在计算区域的分布对计算结果影响不大,从而等距网格和等体积网格都可以达到较高的计算精度.

For the pressure swing absorption processes of rate controlling, the solution of diffusion equations in spherical particles is of great importance. In this paper, the finite difference method is used to solve the diffusion equation and the spherical particle is discretized with iso-spacing grids and iso-volumetric grids respectively. The results show that, when the number of grid in numerical region is fewer, the numerical precision in iso-volumetric grid is higher than that in iso-spacing grid. But when the number of grids is more sufficient, both can reach higher numerical precision.