双级反向旋流器气量分配对燃烧室性能的影响

The variation of air split of dual-stage counter rotating swirlers will have an effect on swirl strength and recirculation zone size.It will further change the mixing uniformity of fuel and air,and finally makes a difference to the NO_x emissions and the lean blowout limits.In order to determine the best scheme of air flow distribution,the effects of airflow split between two swirlers on the NO_x emissions,thermal flow fields and the lean blowout limits were studied experimentally with dual-axial counter rotating swirlers equipped with venturi pipe type premixing section.The experimental results showed that the optimal scheme should be that the air flow ratio of the inner swirler to the outer swirler should be1/0.67.Compared to the baseline with the ratio of 1/1.38,the optimized scheme can reduce the NO_x emissions by 9.4% and 18.5%,respectively,with the value being 39.5 mg/m³and 33.4 mg/m³,under the high and low power conditions.In addition,the lean blowout limit of the optimized scheme is the widest and its LBO (lean blowout) equivalence ratio could be as low as close to zero within the range of study.