微通道内预混乙烯-空气火焰传播和流通特性

Characteristics of premixed ethylene-air flame propagation and flow characteristics in micro-channels

基于Fluent软件,对乙烯-空气预混火焰在四种不同狭缝管道阻火器中的传播以及正常情况下乙烯-空气预混气体通过每种狭缝阻火器的压力降进行了数值模拟研究,对比分析了不同狭缝管道阻火器的阻火性能,并以微圆狭缝为例,分析了狭缝内火焰传播特性。模拟结果表明,火焰在微圆狭缝传播过程中呈现“指尖”状,会发生滞留现象,随后沿着狭缝轴线方向继续向前传播,但在平板狭缝、三角形狭缝和菱形狭缝内未发生此现象。对于微圆狭缝,厚度为100 mm的阻火单元也无法阻火;对于平板狭缝或三角形狭缝,厚度为30 mm的阻火单元可成功阻火;对于菱形狭缝,厚度为10 mm的阻火单元便可成功阻火。在成功阻火且阻火单元数相同的情况下,平板狭缝压力损失最小,菱形狭缝压力损失远大于三角形狭缝和平板狭缝。

Based on Fluent software,the ethylene/air premixed flame state in four different slit duct propagation of flame arrester and the pressure drop of each slit flame arrester under normal conditions were simulated.The flame inhibition performance of four different slit in-line flame arrester was comprised and analyzed.The slit flame propagation characteristics were analyzed with round slit as a case.The simulation results show that the flame shows a"fingertip"shape during the propagation of the micro-circular slit,will be detained and then continues to travel forward along the axis of the slit,but this phenomenon does not occur in the plate slit,triangle slit and diamond slit.For the round slit,the flame resistance unit with a thickness of 100 mm cannot prevent flame.For plate slit or triangular slit,flame resistance unit with thickness of 30 mm can successfully resist flame.For the diamond-shaped slit,flame resistance unit with a thickness of 10 mm can successfully prevent flame.Under the condition of successful flame resistance and the same number of flame resistance units,the pressure loss of the plate slit is the minimum,and the pressure loss of the diamond slit is much greater than that of the triangle slit and the plate slit.