中心分级燃烧室进场工况燃油分级方式试验研究

Experimental Investigation on Fuel-Staging Mode of Internally-Staged Combustor under Approach Condition

设计了一种贫头部中心分级燃烧室,在大推力发动机进场工况参数下,采用单头部矩形试验件,进行了污染排放测试试验,对比了预燃级单独供油、主预两级共同供油、全环主燃级周向分级三种方式的燃烧效率、氮氧化物(NO x)和冒烟(Smoke)排放。试验结果表明,进场工况下,设计的中心分级燃烧室采用预燃级单独供油方式时具有较高的燃烧效率,但NO x排放指数也较高,超过了指标要求;主预两级共同供油方式可获得较低的NO x排放,但燃烧效率难以达到指标;在合理的燃油分配比例下,全环主燃级周向分级方式燃烧效率和NO x排放能够同时满足指标要求;3种燃油分级方式下,冒烟数都远低于指标要求。

A lean-burn internally-staged combustor was designed and the emission experiments using a single module rectangular combustor were operated under the approach condition of a certain large aero-engine.Three fuel-staging modes including the pilot-fueled only mode,the two stages-fueled together mode and the main-fueled circumferentially-staged in the annular combustor mode were investigated experimentally on combustion efficiency,NOx and smoke emission.The experimental results indicate that for this designed internally-staged combustor the combustion efficiency is high with the high NOx emission index (EI) exceeding the target when applying the pilot-fueled only mode.The NOx EI is rather low when applying the two stages-fueled together mode with the combustion efficiency being difficult to reach the target.The combustion efficiency and NOx EI are satisfied for the targets simultaneously when applying the main-fueled circumferentially-staged in the annular combustor mode with the proper fuel-staging proportion.The smoke number (SN) is far below the limited index for all the three modes.