基于凹腔驻涡的无焰燃烧室数值模拟

Numerical Simulation of Flameless Combustor Based on Trapped-Vortex

无焰燃烧的关键在于高温烟气与新鲜空气燃料的充分掺混。本文设计了一种基于凹腔驻涡的无焰燃烧室,并对其进行了零维和三维数值计算。零维数值计算运用简单的化学反应网络模型预测了燃烧室NO_x排放,凹腔当量比为0.5时,NO_x排放低于5 mg/m^3(@15%O_2)。凹腔产生的高温烟气,可以使燃烧室后部温度分布均匀,消除了温度峰值,燃烧室实现了无焰燃烧。双凹腔结构有利于改善燃烧室出口温度分布。

Flameless combustion can be obtained by mixing a large amount of high-temperature burnt gas with fresh air and fuel. This paper designed a flameless model combustor based on trapped-vortex, and zero-dimensional and three-dimensional numerical simulation of the model was taken. Chemical Reactor Network（CNR） method was used in zero-dimension calculation to predict NOx emission of the combustor. When cavity equivalence ratio is 0.5, NOx emission is lower than 5 rag/m3（@15% 02）. The temperature distribution becomes uniformity because of the high-temperature burnt gas, and temperature peak was eliminated, so the combustor had possibility to reach flameless combustion. The temperature profile of the outlet is perfect with doublecavity.