采用大涡模拟的方法研究了燃料分配对燃气轮机燃烧室内压力脉动及NOx生成的影响规律。分析表明：增大值班燃料比使得压力脉动幅值明显降低，脉动频率也有所下降，其降幅则随值班燃料比的增加而减小。这说明，较高值班燃料比条件下，继续增大值班燃料比对燃烧不稳定性的进一步抑制作用减弱。增大值班燃料比使得预混段内温度升高，燃烧反应速率加快，高温区向上游移动，燃烧室内NOx摩尔分数增大，其增幅随值班燃料比的增加而增大。这说明，较高值班燃料比条件下，继续增大值班燃料比导致NOx生成速率进一步增大，不利于控制NOx排放。

Effects of fuel split on the combustion pressure dynamic and NOx emission characteristics were studied using a compressible large eddy simulation method. Increasing the pilot fuel percentage reduces the pressure oscillations and frequency. The fact that the reduction in pressure oscillation amplitude decreases with pilot fuel percentage indicates that further increasing the pilot fuel percentage has relatively smaller impacts on suppressing the combustion. Increasing the pilot fuel percentage also elevates the temperature inside the pre-chamber and thus the reacting rates of premixed fuel stream.Therefore,the region with high temperature moves upstream,resulting in higher mole fraction of NOx inside the combustion chamber. The NOx mole fraction increases with pilot fuel percentage. That is,further increasing the pilot fuel percentage will further exacerbate NOx formation,adversely affecting NOx emission.

TK47

中央高校基本科研业务费专项资金资助项目（2014ZZD04；2014XS17）