Catalytic Combustion Characteristic Study In Micro-slit Combustor

With the rapid development of the micro-machine system techniques such as portable computer, mobile, mini rocket, researches on miniaturization and the miniature system have become one of the most important issues in recent years, which has got widespread concern in any fields. Current researches on micro-power are more than any times, but as the core component micro-combustor needs to be improved, which has been bottleneck for further development of micro-power system.Based on three-dimensional computing platform CALC-BFC, paper is setting up the mathematical model of micro-scale combustion and developing the three dimensional numerical simulation program of methane combustion process in slit-type micro combustor. By simulating CH4 catalytic combustion, flow and heat transfer in micro-combustor and using professional graphics software Tecplot to draw distribution of physical quantities, paper is analyzing the coupling relationship between the physical transfer process and chemical reaction, and discussing the influence of CH4 inlet velocity, inlet temperature and inlet concentration on catalytic combustion in micro combustor.Numerical results show that the appropriate CH4 inlet velocity, inlet temperature and inlet concentration are the main factors of CH4 stable efficient combustion.When CH4 inlet velocity increase, CH4 conversion efficiency decrease obviously. Reaction rate, heat flux are less affected by inlet velocity. In inlet temperature respect, CH4 conversion efficiency essentially unchanged in effective temperature range of Pt catalysis. But the influence on reaction rate, heat flux and temperature distribution of micro combustor are bigger by changing inlet temperature. In addition, with the increase of CH4 inlet concentration, The CH4 conversion efficiency, reaction rate, temperature rise in porous media layer and heat flux increase accordingly.Research shows that for a higher CH4 conversion efficiency, lower temperature rise in porous media, appropriate size of reaction rate and heat flux, the inlet velocity should be smaller, the best suitable inlet temperature is 973 K and the most appropriate CH4 inlet concentration is 0.6%. Results of this paper have important guiding significance on structure development and design of technical parameters of micro combustor.