主燃孔位置对于燃烧室气动力学及点火熄火性能的影响研究(英文稿)

Effects of Primary Jet Position on Combustor Aerodynamic Characteristics and Ignition/LBO Performance

关键词:  燃烧室  主燃孔位置  点火与熄火

Key words:  Combustor  Primary jets position  Ignition/LBO

摘要:

在燃气轮机燃烧室内，通常采用头部旋流装置来稳定火焰，旋流与主燃孔横向射流的交互影响使得燃烧室内主燃区的气动特征非常复杂。本文的研究目的在于分析主燃孔位置变化对于燃烧室流场及点火熄火性能的影响规律。本文研究同一燃烧室中，三个不同主燃孔位置带来的影响。使用商用软件Fluent 13.0进行了本研究冷态流场的数值模拟，得到了旋流杯下游流场的信息。在本研究尺度内，随着主燃孔向燃烧室下游移动，回流流量增加。试验研究了三种方案的点火熄火性能。分别进行了常温常压点火熄火性能试验，常温低压点火性能试验和加温常压熄火性能试验。试验结果表明，随着主燃孔位置向下游移动，燃烧室的贫油点火、熄火边界都变宽，点火熄火性能得到改善。对于常温常压且压降在3%这一典型燃烧室工况而言，[Lp/Hd]=0.9的方案比[Lp/Hd]=0.5的方案贫油点火性能提高了35%。本研究表明主燃孔位置对燃烧室内气动热力及点火熄火性能影响显著。

Abstract:

In a gas turbine engine combustor，highly swirling combustion is usually adopted to stabilize flame and reduce pollutant emissions. The interaction between swirl flow and primary jet flow makes aerodynamic characteristics of the primary combustion zone becoming much complicated. This paper focuses on that primary jet location’s effects on flow field and ignition/LBO performance. In this paper，three cases with different primary jets location have been studied. Non-reacting flow fields were numerically investigated by utilizing the commercial software Fluent 13.0. The numerical results show that flow fields of swirl cup downstream are bound up with the primary jets location. The recirculating mass flow rate increase with the primary jets location moving downstream. Ignition/LBO test has been performed at atmospheric pressure and temperature condition. Ignition test has been performed at low pressure and atmospheric temperature conditon，and LBO test has been performed at elevated temperature and atmospheric pressure. Their lean ignition limits and lean blowout limits are obtained. Ignition/LBO test results show that ignition/LBO limit become wider with the primary jets location moving downstream both at ground condition and low pressure condition. That’s indicate，within the scope of this research，ignition/LBO performance improves with the primary jets location move downstream. At the typical condition (atmospheric pressure and temperature and [Δp]=3%)，the lean igniton limit improve 35% when primary hole position move from [Lp/Hd]=0.5 to [Lp/Hd]=0.9. The results demonstrate that the location of the primary hole strongly influence the aerodynamic and ignition/LBO characteristics of combustor.