多旋流LPP影响燃烧特性的数值分析

Numerical analysis of the LPP effects on combustion characteristics in combustion of multi-swirling flows

对贫油经由双级旋流器在突扩燃烧室内的旋流扩散燃烧反应进行了CFD数值研究。通过改变一级旋流器和二级旋流器的空气流量分配,定量研究了旋流杯内油气的局部混合和蒸发对双旋流燃烧特性的影响。结果表明,合理的气量分配使旋流杯内的油气具有较明显的贫油部分预混合预蒸发LPP效应;使燃烧室头部区域具有LPP燃烧特性:头部燃烧区位置和结构合理,温场峰值低且比较均匀,产生较少的NO污染物。相关计算结果与试验结果相符合。

In this paper,swirling diffusion combustion in the sudden expansion combustion chamber with double swirling is studied by numerical simulation.By changing air flow distribution between the first stage and secondary stage,the effects of local air/oil gas mixture distribution on the combustion characteristics of the swirling reaction zone is numerically analyzed.The results show that a reasonable flow distribution has a more pronounced partially lean premixed pre-evaporation（LPP） effect in swirling cup,thus having the LPP lean combustion characteristics： Location and structure of the head reaction zone are reasonable and the temperature fields have lower peak value and is more uniform distributed,producing less NO pollutants.Computing results are consistent with those of related experiment.