一次航班飞行全过程大气污染物排放特征

飞机发动机以航空煤油为燃料,在运行过程中会排放多种大气污染物,对空气质量和人体健康存在较大影响.选择A320作为典型机型,提取了一次真实航班飞行过程中的机载飞行数据,基于BM2及BM2-FOA耦合模型,获得了其在飞行全过程中每一时刻CO、UHC、NO_x及PM_(2.5)的排放指数,并计算了CO、UHC、NO_x、SO_2、CO_2及PM_(2.5)的精确排放量.结果表明,飞行过程中CO和UHC排放指数与推力变化趋势相反,数值范围分别为0.67~595.34 g·kg~(-1)和0.05~0.43 g·kg~(-1).NO_x排放指数与燃油流量变化趋势一致,数值范围是0.96~114.25 g·kg~(-1).PM_(2.5)排放指数全过程变化较小,约为0.25~0.36 g·kg~(-1).飞行全过程中,CO_2排放总量最大,约为2.0×10~4kg.同时,NO_x的排放量约为213.4 kg,SO_2也排放了24.5 kg.CO、PM_(2.5)和UHC的排放量分别为7.5、2.2和0.5 kg.将本次精确计算结果与使用ICAO基准模型对LTO起降阶段的估算结果进行对比后发现,基准模型LTO飞行时间较真实时间偏长37%.基准模型估算LTO阶段CO、UHC污染物排放量偏高,NO_x偏低,且偏差较大;而SO_2、CO_2和PM_(2.5)的排放量估算结果偏差相对较小.与机动车相比,A320飞机的一次LTO起飞着陆飞行,NO_x排放量约等于一辆小客车行驶8.6×10~4km,或相当于1274辆小客车1 d的排放量.

Emission characterization of civil aviation aircraft during a whole flight

Aircraft engines use aviation kerosene as fuel to provide power. Various kinds of air pollutants are emitted during operation, impacting human health and environment. Airbus A320 was selected as a typical type in the study. The flight record data during a real flight was decoded. The study acquired the emission indices of CO, UHC, NO_x and PM_2.5 at each phase of the whole flight, basing on the coupling model of BM2 and BM2-FOA, and calculated the accurate emissions of CO, UHC, NO_x, SO₂, CO₂ and PM_2.5,respectively. According to the results, the emission indices of CO and UHC, which are within 0.67 to 595.34 g·kg^-1 and 0.05 to 0.43 g·kg^-1 respectively, are inversely proportional to the variation trend of engine thrust. The emission index of NO_x, which is within 0.96 to 114.25 g·kg^-1, is in conformity with the variation trend of fuel flow. The index of PM_2.5 is in the range of 0.25 to 0.36 g·kg^-1, showing little changes during the whole flight. CO₂ is the most abundant emission during the flight. The emission of it is about 2.0×10⁴ kg. Meanwhile, the emission of NO_x is about 213.4 kg, and SO₂ is about 24.5 kg. The emissions of CO, PM_2.5 and UHC are 7.5, 2.2, 0.5 kg, respectively. Compared with this paper, the LTO flight time of the ICAO standard model is 37% longer than the real LTO flight time. Therefore, processed by the standard model, the LTO emissions of CO and UHC are higher, and the LTO emission of NO_x is lower. All these emissions, calculated by standard model, show relatively great deviations. However, the estimated emissions of SO₂, CO₂ and PM_2.5 have no significant difference. And the emission level of NO_x of A320 during LTO flight is approximately equal to the emission level of a compact car traveling 8.6×10⁴ km, or 1274 compact cars traveling for one day.