当量比和反应物混合模式对无焰燃烧的影响

Effects of Equivalence Ratio And Mixing Pattern of Reactants on Flameless Combustion

给出空气和燃料在3种初始混合模式（非预混、部分预混和完全预混）下无焰燃烧的实验结果，介绍了无焰燃烧的实现方法，研究当量比和初始混合模式对无焰燃烧的影响。实验炉在功率为7.5~15 kW下运行，当量比的变化范围为0.5~1。实验结果表明，无焰燃烧状态一旦建立则很稳定，很容易维持。无论是预混、非预混还是部分预混燃烧，其炉温差别不大，CO和NOx排放低。当量比接近1时，虽然炉内仍处于无焰燃烧状态且NOx排放量少，但CO和H2排放量都极多，此时并不是清洁燃烧。当量比小于0.98时，3种混合模式下烟气中的CO和H2含量都极低，但部分预混无焰燃烧产生的NOx排放量相对较多，而完全预混无焰燃烧的NOx排放量最低。文中还对当量比对NOx排放量的影响进行了详细分析。

reported the experimental results of flameless combustion obtained from investigation of the influence of equivalence ratio and initial reactants mixing pattern. The furnace operates at the thermal input of 7.5- 15 kW, and equivalence ratio varying from 0.5 to 1. Experiments show that the flameless combustion is easy to maintain once it has been established. It is found that, regardless of using non-premixing, partially premixing or fully premixing pattern, the furnace temperature is similar while CO, H2 and NOx emissions are extremely low. When the equivalence ratio is near 1, although it is still in the flameless mode and NOx emissions are low, extremely high CO and H2 emissions are obtained and thus the combustion is not clean. When the equivalence ratio is less than 0.98, CO and H2 emissions are low in all the three cases, and relatively, the partially premixing produces the most of NOx whereas the fully premixing obtains the lowest. This paper also discussed the influence of equivalence ratio on NOx emissions in detail.