一种双级径向旋流燃烧器的燃烧特性模拟分析

Simulation Analysis of Combustion Characteristics of A Two-stage Radial Swirler

径向旋流器广泛应用于航空发动机和重型燃气轮机的燃烧室,用于流动、掺混和燃烧组织。本文针对一种贫预混燃烧室开展了数值模拟研究,该燃烧器采用双级旋向相反的径向旋流器设计。通过对旋流器出口及燃烧室内速度场、燃料浓度场、湍动能分布、反应区分布等特性的计算,分析了火焰结构的形成机制。结果表明,目前结构和设计条件下,该贫预混燃烧室流动和燃烧过程组织合理,火焰区域燃料浓度分布均匀并可有效避免熄火,可以有效控制NOx的排放水平。

Radial swirlers are widely used for the arrangement of flow,mixing and combustion in the combustors of aeroengines and gas turbines.This paper introduces the investigation on a lean-premixed combustor with two reverse radial swirlers by CFD.The flow field,the distribution of fuel concentration,the kinetic energy of turbulence and the distribution of reaction zone are simulated and analyzed for the region near the outlet of the swirler and inside the combustor.The mechanisms for the formation of the flame structures are analyzed.The investigations show that the arrangements of flow and combustion are proper for the structure of combustors as investigated.The distributions of fuel concentration are uniform and the flame blowout phenomenon can be effectively avoided.The emission of NOx can also be reduced to a very low level by this design.