Numerical modeling of microchannel reactor with porous surface microstructure based on fractal geometry

Abstract

A microchannel reactor with porous surface for hydrogen production can enhance fluid flow and heat transfer characteristics. To improve the fluid flow and heat transfer characteristics of a microreactor with a porous surface, a numerical model is proposed based on fractal geometry. The porous surface in the microreactor is fabricated using a layered powder sintering and dissolution method with NaCl particles, in which two sizes of NaCl particles (180–280 μm and 280–450 μm) are utilized. For the construction of the porous surface, these two types of fabricated surfaces are measured and the fractal dimensions are characterized as 1.905 and 1.849, respectively. Subsequently, a numerical model based on fractal geometry for a microchannel reactor with porous surface is developed to study the fluid flow and heat transfer characteristics. This is followed by the microchannel reactor fabrication and experimental testing. Both model calculation and experimental results demonstrate that a microreactor with a porous surface can enhance the heat transfer performances compared with that with a non-porous surface, and that a microchannel reactor fabricated with larger NaCl particles (280–450 μm) has better heat transfer characteristics compared with a microreactor with small NaCl particles (180–280 μm). Thus, the developed numerical model based on fractal geometry can be used to accurately predict the fluid flow and heat transfer characteristics of the microreactor for hydrogen production.