Numerical Simulation Of Catalytic Combustion Of Methane In Micro-channels

Micro-power system is the fourth milestone of the development of power machine, which has broad application in the construction of national defence and economy, working on our society materially. Studies of it have already been done allover the world, but only focus on technology and technics. There are not crucial progressing in the key problem such as how to realize micro-combustion. In recent years, combustion researchers have increasingly taken cognizance of the importance and pressing of study on micro-combustion, especially on catalytic combustion of methane in micro-scale. No other entity has done any research on this point interiorly up to now. This paper was preformed numerical simulation for catalytic combustion of methane in micro-scale, summarized the influence on catalytic combustion of gas-phase combustion, velocity, temperature, heat transfer, and equivalence ratio and so on; For excess-enthalpy combustor, bring forward an improved project named "choose special heat transfer coefficient for special wall", and compared the catalytic combustion before and after bring forward the improved project.In the first depart of this paper, numerical simulation was done for catalytic combustion of methane/air mixture in micro-channel, influence of relational factors on catalytic combustion was studied by the numbers and got conclusions as: heat transfer is fateful factor of catalytic, combustion couldn't last when the heat-transfer coefficient be too high; equivalence ratio is primary factor, conversion rate of methane will increase firstly and decrease secondly as the equivalence ratio increased; temperature of wall is important factor, conversion rate of methane will increase as the temperature increased; under the precondition of enough high temperature, the increase of velocity of methane /air mixture would make catalytic combustion more forceful; gas-phase combustion is difficult to be produced and may be ignored under the condition of micro-scale, increase the diameter of channel will restrain catalytic at the same time; what's more, catalytic combustion can hold up gas phase combustion. In the second depart of this paper, the catalytic combustion of methane /air mixture in excess-enthalpy combustor was studied numerically and got conclusions as: the conflict between increasing heat transfer and increasing difference in temperature can be solved by the improved project named "choose special heat transfer coefficient for special wall" in the excess-enthalpy combustor. Under the perfect condition, heat released by fuel can be entirely used, and the max value of difference in temperature can be increased by one or two order of magnitude.