使用Chemkin—Pro对CH4富氧燃烧特性(层流火焰传播速度、自点火延迟时间、化学反应特征时间及污染物的排放)在典型燃气轮机运行条件下进行了计算.计算采用GRI—Mech3.0详细化学反应机理,包括53种组分,325个基元反应.结果表明,对于带有碳捕集的系统,当量比增加2%,便可以使得排气中氧气浓度下降50%;设计CH4/空气所用的自点火延迟时间的经验或准则也同样适用于CH4/02/H20;当CH4/02/H20中氧气的体积分数为26%~27%时,富氧燃烧室的回火、吹熄以及出口温度特性与以CH4/空气为燃料的燃气轮机最接近,此时对原型燃烧室的结构改动最少.
Laminar flame speed, ignition delay time, chemical characteristic time and pollution emission of CH4/O2/H20 in typical gas turbine condition were calculated by Chemkin-Pro. A detailed reaction mechanism GRI- Mech 3.0, which includes 53 species and 325 elemental reactions were used. The following conclusions are drawn: with CO2 capture system, the 02 concentration in exhaust gas is reduced 50% while the equivalence ratio increases by only 2%; the experiential rules for auto-ignition of CH4 and air mixture are also suitable for CH4/O2/H20; when the 02 volume fraction in mixture CH4/O2/H20 remains about 26%--27%, flashback, blow-off and temperature charac-teristic at outlet of oxy-fuel combustion combustor are nearly the same as those of CH4/air gas turbine, and then the modification of original combustor is the least.