旋流器结构对贫油直喷燃烧室的性能影响

针对单元贫油直喷(LDI)喷嘴的旋流器设计问题,实验研究了旋流器结构变化(改变旋流器级数、双旋流器旋向及混合段收缩角等)对燃烧室总压损失、燃烧效率以及污染物排放等性能的影响规律.结果表明:旋流器结构变化对燃烧室性能有很大影响.同向双旋流燃烧室总压损失大于与之相同计算旋流数的单级旋流燃烧室,反向双旋流燃烧室总压损失略低于同向双旋流燃烧室,燃烧室总压损失随收缩角增大而呈增大趋势.相较单级旋流燃烧室和同向双旋流燃烧室,反向双旋流燃烧室在不同贫油气比工况下均具有更高的燃烧效率和更低的污染物排放.另外,燃烧效率及污染物排放受收缩角的影响.最佳收缩角角度的选取需要综合权衡总压损失、燃烧效率及污染物排放水平.

Effects of swirler structure on the performance of lean-direct-injection combustor

In consideration of swirler design of single element lean-direct-injection (LDI) injector, the effects of the swirler structures, including swirler stage number, swirl direction of dual-stage swirler and shrinking angle of mixing section, on the combustor performance (total pressure loss, combustion efficiency and pollutant emissions) were studied experimentally. The results show that, the swirler structures have great effect on the performance of combustor. The total pressure loss of dual-stage co-swirl combustor is greater than that of the single-stage swirl combustor with the same swirl number as the dual-stage co-swirl combustor. The total pressure loss of dual-stage counter-swirl combustor is slightly lower than that of the dual-stage co-swirl combustor. Combustor's total pressure loss increases with the inerease of shrinking angle. Under different lean fuel-air ratios, compared to the single-stage swirl combustor and dual-stage co-swirl combustor, the dual-stage counter-swirl combustor has higher combustion efficiency and lower pollutant emissions. In addition, combustion efficiency and pollutant emissions are affected by the shrinking angle. The optimal shrinking angle selection should strike a blance among the total pressure loss, the combustion efficiency, and the level of pollutant emissions.