热流量法测量高压CH4/O2/N2/CO2的层流火焰速度

Laminar Burning Velocity of CH4/O2/N2/CO2 Flames Measured by Heat Flux Method at Elevated Pressure

热流量法成功应用在高压(0.5 MPa)下甲烷稀释气的绝热无拉伸层流火焰速度的测量.针对当量比为0.6~1.6、不同含氧量和固定含氧量时不同CO2稀释度的火焰速度进行了实验和动力学探究.模拟采用GRIMech和HP-Mech两个反应机理,在不同压力下均给出了十分吻合实验值的预测结果.层流火焰速度的相对增量独立于当量比和压力的变化.总反应级数随氧含量提高和CO2稀释度降低而增大,相同的绝热火焰温度的总反应级数相近.在不同稀释度情况下CO2对层流火焰速度的热扩散贡献在50%以上,且随着压力提高,热扩散贡献减小而化学反应贡献增加.

The heat flux method was successfully applied to adiabatic stretch-less laminar burning velocity measurements of CH4/O2/N2/CO2 at pressure up to 0.5MPa and equivalence ratios ranging 0.6-1.6 with different oxygen contents and with the same oxygen content but different CO2 dilutions.Two kinetic mechanisms,i.e.,GRIMech and HP-Mech,were used,under which both of the experimental and numerical results agreed well at different pressures.The relative increase in the laminar burning velocity is independent of pressure and equivalence ratio.The overall reaction order increases as the oxygen content increases and CO2 dilution decreases,while the fuels with the same adiabatic flame temperature have similar overall reaction orders.The thermal-diffusion effect of CO2 dilution is more than 50%for all the cases,and as pressure increases,the thermal-diffusion effect decreases while the chemical effect increases.