单旋流驻涡燃烧室流场结构的数值模拟

Numerical Simulation on Single Swirl Trapped-Vortex Combustor Flow

关键词:  旋流  驻涡燃烧室  燃烧室性能  NO_x排放

Key words:  Swirl  Trapped vortex combustor  Combustor performance  NO_x emission

摘要:

为进一步发展低排放、高效燃烧技术，提出了带导流片的单旋流驻涡燃烧室。改变旋流通道轴向长度及旋流器内外径比，数值分析了其内部燃烧湍流流场。结果表明:旋流通道结构参数及旋流器内外径比对总压损失影响较小，而对燃烧效率影响较大。在多种旋流通道结构参数匹配下均实现了低NO_x排放，最佳匹配结构参数为阻塞比BR=0.6，旋流通道长度与燃烧室长度比[Zs/Lc]=0.093，旋流器外径[Ro]=16mm，内外径比[Ri/Ro]=0.888；当旋流器外径Ro较小或较大时，内外径比[Ri/Ro]对排放性能影响不大；当[Ro]适中时，[Ri/Ro]对排放性能影响很大，NO_x排放随[Ri/Ro]的增加呈指数型增加。

Abstract:

A single 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 axial length of swirler channel and the ratio of inner radius to outer radius. The results show that axial length of swirl channel and the ratio of inner diameter to outer diameter have small impact on total pressure loss，but they have relatively big effect on combustion efficiency. Low NO_x emission is obtained?by the various matching structure parameter of swirl channels. Optimal matching structure parameter is blockage ratio?BR=0.6，the ratio of swirler channel length to combustor length [Zs/Lc]=0.093，outer radius [Ro]=16mm and the ratio of inner radius to outer radius [Ri/Ro]=0.888. When swirler outer radius [Ro] is smaller or bigger，the ratio of inner radius to outer radius [Ri/Ro] has small impact on NO_x emission. When [Ro] is moderate，[Ri/Ro] has big impact on NO_x emission，NO_x emission increases exponentially with the increase of [Ri/Ro].