Numerical Simulation on Catalytic Combustion of Hydrogen inside Micro Tube

Advanced Materials Research (Volumes 354 - 355) Pages 57-61 (2011)
Numerical Simulation on Catalytic Combustion of Hydrogen inside Micro Tube
Jun Jie Chen, Qian Wang, Zhi Xia He, Jian Feng Pan
Abstract
Researchers investigated the catalytic combustion of hydrogen/air mixture inside micro-tube with detailed gas phase and surface catalytic chemical reaction mechanisms. Combustion characteristics for a number of reaction models, including the influence of wall thermal conductivity, inlet velocity, and tube diameter on surface catalytic combustion reaction, are discussed.
Results suggest that the surface catalytic combustion restrains the gas phase combustion. The higher wall temperature gradient for low wall thermal conductivity promotes the gas phase combustion shift upstream, resulting in a higher temperature distribution. The micro-tube can be divided into an upstream and a downstream region. The upstream region is dominated by the surface catalytic reaction.  The downstream region is dominated by the gas phase combustion. With increasing inlet velocity, the region dominated by surface catalytic reactions expanded downstream, ultimately occupying the whole tube. The temperature of the flame core decreases with the decrease of tube diameter. Decreasing the tube diameter enhances the surface catalytic reactions.
Full Text Source (Subscription or Fee): http://www.scientific.net/AMR.354-355.57