光催化制氢反应器内液固两相分布特性模拟研究

NUMERICAL SIMULATION OF SOLID-LIQUID DISTRIBUTION IN PHOTOCATALYTIC REACTOR FOR HYDROGEN PRODUCTION

针对光催化制氢反应器的特点,基于Sato叠加假设考虑颗粒对液相湍流的影响,运用CFX的双流体模型,对反应器水平管道内的液固两相流动进行了数值模拟,得到了相应的催化剂颗粒分布、湍流强度分布及相速度分布。结果表明,在液固两相流动条件下,催化剂颗粒在底部形成沉积层,而在管道中心区域,形成拟均匀的悬浮流动形态,这种类型的催化剂颗粒分布对光催化反应的充分进行是不利的。根据两相的速度分布,发现相间的滑移并不明显,这说明催化剂颗粒几乎是随着流体流动的,在实际中,可以运用代数滑移模型(ASM)对这种流动进行模拟计算。

Based on the characteristics of photocatalytic reactor for hydrogen production, the solid-liquid two-phase flow in the horizontal pipe of reactor was numerically studied by CFX with two-fluid model. The distribution characteristics of solid-liquid two-phase flow were obtained. The results show that a catalyst deposit layer exists at the pipe bottom, and a quasi-homogeneous suspending state appears in the core area, while nearly no catalyst appears at the top of the pipe. This type of catalyst distribution should be avoided during the operations of this photocatalytic reactor. And according to the velocity distribution, the slip between the phases is not obvious, which means the catalyst particles are almost along with the fluid. So the algebraic slip mixture （ASM） model can be used in this condition.