微燃烧器内甲烷催化燃烧的数值模拟

Numerical Simulation of Catalytic Combustion of CH_4 in a Micro-burner

联合使用CFD软件、FLUENT和化学反应动力学软件DETCHEM对甲烷 -空气混合物在有逆流换热的微燃烧器内的催化燃烧进行了数值模拟。计算中只考虑了甲烷在催化表面上的反应。燃料 -空气混合物的当量比为 0 .4 ,燃烧器外壁面分别采用等温边界条件和与环境的对流换热边界条件 ,并比较了这两种边界条件对可燃混合气燃烧的影响。计算结果表明 ,催化燃烧可以实现常规方法无法实现的甲烷低温、高效转变。

By making use of software CHD FLUENT and chemical reaction dynamics software DETCHEM a numerical simulation was conducted of the catalytic combustion of a mixture of CH_4 and air in a micro-burner featuring counter-flow heat exchange. During the calculations only the reaction of CH_4 on a catalytic surface has been taken into account. The stoichiometric ratio of fuel-air mixture is 0.4. Isothermal boundary condition and ambient convection heat-exchange boundary condition have been adopted for the burner outer wall surface. The impact of these two kinds of boundary condition on the burning of combustible fuel-air mixture was compared. Calculation results show that catalytic combustion has made it possible to realize the low-temperature and high-efficiency conversion of CH_4, which cannot be carried out by a conventional method.