Purpose

This paper aims to predict the effect of combustor inlet area ratio (CIAR) on the lean blowout limit (LBO) of a swirl stabilized can-type micro gas turbine combustor having a thermal capacity of 3 kW.

Design/methodology/approach

The blowout limits of the combustor were predicted predominantly from numerical simulations by using the average exit gas temperature (AEGT) method. In this method, the blowout limit is determined from characteristics of the average exit gas temperature of the combustion products for varying equivalence. The CIAR value considered in this study ranges from 0.2 to 0.4 and combustor inlet velocities range from 1.70 to 6.80 m/s.

Findings

The LBO equivalence ratio decreases gradually with an increase in inlet velocity. On the other hand, the LBO equivalence ratio decreases significantly especially at low inlet velocities with a decrease in CIAR. These results were backed by experimental results for a case of CIAR equal to 0.2.

Practical implications

Gas turbine combustors are vulnerable to operate on lean equivalence ratios at cruise flight to avoid high thermal stresses. A flame blowout is the main issue faced in lean operations. Based on literature and studies, the combustor lean blowout performance significantly depends on the primary zone mass flow rate. By incorporating variable area snout in the combustor will alter the primary zone mass flow rates by which the combustor will experience extended lean blowout limit characteristics.

Originality/value

This is a first effort to predict the lean blowout performance on the variation of combustor inlet area ratio on gas turbine combustor. This would help to extend the flame stability region for the gas turbine combustor.

中文翻译：

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微型燃气轮机燃烧室燃烧室入口面积比变化对稀喷性能的预测

目的

本文旨在预测燃烧室入口面积比 (CIAR) 对热容量为 3 kW 的涡流稳定罐式微型燃气轮机燃烧器的稀燃极限 (LBO) 的影响。

设计/方法/方法

燃烧器的井喷极限主要通过使用平均出口气体温度 (AEGT) 方法的数值模拟来预测。在该方法中，爆燃极限是根据不同当量的燃烧产物的平均出口气体温度的特性确定的。本研究中考虑的 CIAR 值范围为 0.2 到 0.4，燃烧室入口速度范围为 1.70 到 6.80 m/s。

发现

LBO 当量比随着入口速度的增加而逐渐减小。另一方面，随着 CIAR 的降低，LBO 当量比显着降低，尤其是在低入口速度下。这些结果得到了 CIAR 等于 0.2 的情况下的实验结果的支持。

实际影响

燃气轮机燃烧器很容易在巡航飞行中以稀薄当量比运行以避免高热应力。火焰熄灭是精益操作面临的主要问题。根据文献和研究，燃烧室稀薄井喷性能显着取决于主区质量流量。通过在燃烧器中加入可变面积的喷口将改变主区质量流率，通过该流率，燃烧器将经历延长的稀燃极限特性。

原创性/价值

这是对燃气轮机燃烧室燃烧室入口面积比变化预测稀燃性能的首次尝试。这将有助于扩展燃气轮机燃烧器的火焰稳定区域。