低排放燃烧室单头部和全环试验及排放预测研究

Emission Test and Prediction Investigation for Low Emission Single Cup and Annular Combustor

关键词:  民用航空发动机  排放试验  排放预测  贫油燃烧  分级燃烧

Key words:  Civil aero engine  Emission test  Emission prediction  Lean burn combustion  Staged combustion

摘要:

为了研究中心分级贫油低排放燃烧室的排放特性，在单头部和全环燃烧室试验件上测量了一种低排放头部方案的排放性能，研究了排放预测方法。试验结果表明：单头部和全环的UHC和NO_x接近，而CO差异较大，原因是CO受边界影响较大；CO和UHC主要与最高燃烧温度相关；当仅预燃级供油时，NO_x主要受最高燃烧温度控制，而当预燃级和主燃级同时供油时，NO_x主要受燃烧区平均温度和分级比控制。采用经验方法研究了排放预测方法，结果表明：单头部和全环预测结果与试验结果均符合较好；采用单头部预测公式预测全环排放时，CO和NO_x预测偏差较大，而UHC预测效果较好，CO偏差大是边界的影响导致，NO_x偏差大是全环试验油气比和分级比范围超出单头部试验范围导致。

Abstract:

A low emission combustor was tested in single-cup and annular combustor to understand emission trend of central staged lean burn combustor. Comparing the emission results from the two tests， UHC and NO_x measurements are close， CO emission highly influenced by boundary conditions is quite different. CO and UHC emissions are controlled by stoichiometric temperature. When only pilot injector works， NO_x emission is controlled by stoichiometric temperature and when both pilot and main injectors work， it’s controlled by combustion zone average temperature and fuel split ratio. Good prediction for both single cup and annular tests was obtained using empirical method. Prediction model based on single cup test data was used to predict annular combustor test emission levels. UHC prediction agrees well， CO and NO_x have obvious deviation because of boundary difference and wider test range of fuel air ratio and fuel split ratio for annular combustor test.