Lean operation in the primary combustion zone of a gas turbine combustor is advantageous from ${\mathrm{NO}}_x$ reduction point of view. The present work deals with the influence of lean primary zone operation on combustion performance, ${\mathrm{NO}}_x$ emissions, and flame stability of a model gas turbine combustor with simplex atomizer. Air distribution is varied to operate the primary combustion zone from stoichiometric to leaner operating conditions (${\mathrm{\Phi }}_{\mathrm{pri}}=1.04–0.61$), at fixed fuel flow rate and overall air–fuel ratio. Combustor performance is quantified with the help of gas temperature profile at exit and species concentrations at the end of primary zone. It is found that a primary zone equivalence ratio of 0.79 is optimal for high combustor efficiency and low ${\mathrm{NO}}_x$ emissions, with a stable flame. When the primary zone equivalence ratio approaches the lean blowout (LBO) limit (${\mathrm{\Phi }}_{\mathrm{pri}}\sim 0.5$), intermittent low–frequency, high-amplitude pressure oscillations arise, especially at higher primary zone air flow rates. Inclusion of a metallic ring in the primary combustion zone widens the equivalence ratio for flame stability, with a small reduction in combustion efficiency. It also reduces the noise level and suppresses the intermittent high-amplitude oscillations close to LBO.

在燃气轮机燃烧器的主燃烧区中的稀薄运行具有以下优点： ${\mathrm{没有}}_X$还原的观点。目前的工作涉及稀薄初级区运行对燃烧性能的影响，${\mathrm{没有}}_X$带有单一雾化器的模型燃气轮机燃烧室的气体排放和火焰稳定性。改变空气分布以使主要燃烧区从化学计量运行到更稀薄的运行状态（${\mathrm{\Phi }}_{\mathrm{pri}}=1.04–0.61$），固定的燃油流量和总的空燃比。燃烧器的性能借助出口处的气体温度曲线和主要区域末端的物质浓度进行量化。发现对于高燃烧器效率和低燃烧器，主区当量比为0.79是最佳的${\mathrm{没有}}_X$排放，并具有稳定的火焰。当主要区域的当量比接近稀燃（LBO）极限（${\mathrm{\Phi }}_{\mathrm{pri}}〜0.5$），会出现间歇性的低频高振幅压力振荡，尤其是在较高的主要区域空气流速下。在主燃烧区中包含金属环可扩大等效比，以提高火焰稳定性，并降低燃烧效率。它还可以降低噪声水平并抑制接近LBO的间歇性高振幅振荡。