飞机发动机排气污染物的测量

Gas Turbine Engine Emissions Measurement

参考国际民航组织(ICAO)颁布的“飞机发动机排放”条例的规定,设计并建立了民用航空发动机排气污染物测量系统,采用自行推算的样气成分“干基”向“湿基”转换的修正公式,编写排放物EI的计算程序。在民航维修基地(AMECO公司)的试车台对二台JT3D-7型发动机进行排气污染物的实测,测出的各类污染物的排放指数EI_(CO),EI_(HC),EI_(NOx)及冒烟数SN,并与JT3D-7型发动机公布的数据进行对比,测量系统的精度按标准规定用燃气分析测出的气油比与发动机实测的气油比进行比较小于10％～15％的均属于合格,本研究的系统的测量值与发动机所测的总气油量之比的误差在3％左右,证明此测量系统和测量技术切实可行。

With reference to ' Aircraft Engine Emissions' promulgated by the convention on International Civil Aviation,we designed an emission measuring system. Emissions of two JT3D-7 gas turbine engines were measured by means of the system on the test rig of AMECO company. The measured Emissions Index EIco,EIHC,EINOx and SN of these two engines were compared with the JT3D-7 typical EI data. The accuracy of this system is about 3%, which was much better than the ICA's requirement (10%-15%). In the analytical formulations for the EI and AFR parameters of the convention, assumptions were made that all concentration measurements were of the ' wet sample'. In our practice, the CO2, CO and NOx concentration measurements were made on a 'dry' basis. So we derived the corrected formulations for EI and AFR calculations of these engines. The data of experiments were varied in a quite wide range to prove that the sampling and measurement system is acceptable in engineering.