双旋流驻涡燃烧室湍流燃烧流动的数值分析

Numrical Simulation on Turbulence Flow in Dual Swirl Trapped-Vortex Combustor

提出了带导流片的双旋流驻涡燃烧室以进一步发展低排放、高效燃烧技术。改变旋流器的结构参数以及旋向,对双旋流驻涡燃烧室内部燃烧湍流流场进行了数值模拟。结果表明:增大旋流器内外径比对燃烧效率有一定影响,NO_x排放降低了约8%。旋流器中心间距对燃烧性能的影响不如内外径比的大。不同旋向下燃烧室均可获得良好的双涡结构,但反旋时下游火焰筒的高温度梯度场会对筒壁造成强烈热冲击,同旋时NO_x排放降低了约22%,因此同向旋转结构总体上要优于反向旋转结构。

A dual swirl trapped vortex combustor with guide vane is proposed in order to develop low pollution and high efficiency combustion technology,and numerical simulation of combustion turbulence flow was performed by changing swirler structure parameters and rotation direction. The results show that with the increase of inner diameter and outer diameter ratio,to some extent,combustion efficiency increased,but NOx emission decreases by about 8%. The influence of distance between two swirlers center on combustion performance is less than that of inner diameter and outer diameter ratio. Good double vortex structure can be obtained for this type combustion chamber with different rotation direction, but extremely high temperature gradient of downstream flame tube caused by counter-swirl will produce strong thermal shock to the cylinder wall. Co-swirl combustor can decrease NOx emission by about 22% and achieve better comprehensive performance than counter-swirl combustor.