低排放燃烧室NOx排放试验及预测方法研究

NOx Emission Test and Prediction Method for Low Emission Combustor

关键词:  航空发动机  排放试验  排放预测  贫油燃烧  分级燃烧  燃油分级

Key words:  Aero-engine  Emission test  Emission prediction  Lean combustion  Staged combustion  Fuel stage

摘要:

为了研究中心分级贫油低排放燃烧室的排放特性和排放预测方法，针对一个低排放头部方案，在单头部燃烧室试验件上，在不同的温度、压力、油气比、供油模式和分级比条件下，测量其排放性能。以Lefebvre排放经验预测公式为基础，采用经验分析方法拟合排放试验数据，归纳出适用于本头部方案的排放预测公式。表征预测好坏的判定系数R²在小工况下和大工况下分别为0.95和0.93，表明预测结果与试验结果符合度较好。小工况和大工况排放特性不同，对仅预燃级喷油的小工况工作模式，NO_x排放主要受化学恰当燃烧温度和预燃级局部当量比的影响；对预燃级和主燃级同时喷油的大工况工作模式，NO_x排放主要受燃烧区温度和主燃级燃油比例的影响。

Abstract:

Better understanding of emission behavior and emission prediction method for central staged lean low emission combustor are needed. Low emission combustor was tested on a single injector combustor test rig. Emission was measured under varied temperature, pressure, fuel air ratio, fuel split mode and pliot fuel proportion. Empirical method based on Lefebvre equation was used to analyze the emission data, and emission prediction method suitable for present injector was recommended. Coefficient R² for prediction effect judgement are 0.95 and 0.93 for low power and high power, respectively. Good prediction effect compared with experiment was obtained. Emission behavior at low power and high power state are different. At low power state with pliot fuel only, NO_x emission are influenced mainly by stoichiometric flame temperature and pilot zone equivalence ratio. At high power state with both pilot fuel and main fuel, NO_x emission are influenced mainly by combustion zone temperature and main fuel ratio.