不同环境温度下E10轻型车CO_(2)排放研究

Study on CO_(2) Emission of E10 Light-Duty Vehicle Under Different Ambient Temperature

全球变暖使得机动车排放的温室气体受到重视。为量化温度对车辆CO_(2)排放的影响,本研究在−10、0、23和40℃的环境温度下对一辆轻型E10汽油车进行了WLTC测试循环,发现热起动时-10和0℃的CO_(2)排放因子相较23℃分别高了10.4%和20.8%,冷起动时车辆实现完全热机的时间长于国六标准要求的300 s。相对偏差因子RF在车辆完全热机时接近于1,而23和40℃分别在RF_(4)和RF_(3)接近1,说明环境温度越高,实现完全热机所需的时间就越短。-10℃时绝对偏差因子AF_(1)和AF_(2)分别是23℃的1.98倍和3.63倍,量化了冬季与夏季车辆冷起动CO_(2)排放的差距。累积CO_(2)排放与怠速CO_(2)排放因子存在很强的相关性,可用于建立或修正微观CO_(2)排放模型,并建议在评估车辆CO_(2)排放时考虑环境温度的变化。

As a result of global warming,attention has been paid to greenhouse gas emitted by vehicles.In order to quantify the effect of temperature on vehicle CO_(2) emission,WLTC test cycle of a light-duty E10 gasoline vehicle is carried out at the ambient temperatures of-10,0,23 and 40℃i n this study.It is found that the CO_(2) emission factors of-10 and 0℃at hot-start are 10.4% and 20.8% higher than those at 23℃,respectively.For cold-start engine,achieving full warm-up is longer than 300 s,which is required by China 6 standard.The relative deviation factor RF of the vehicle with full warm-up is close to 1,and 23 and 40℃ are close to 1 at RF_(4) and RF_(3),respectively,indicating that the higher the ambient temperature,the shorter the time required to achieve full warm-up.The absolute deviation factors AF_(1) and AF_(2) at -10℃ are 1.98 and 3.63 times higher than those at 23℃,respectively,which quantifies the difference of CO_(2) emission of cold-start vehicles in winter and summer.There is a strong correlation between cumulative CO_(2) emission and idle CO_(2) emission factors,which can be used to establish or modify microscopic CO_(2) emission models,and it is suggested that the change of ambient temperature should be taken into account when evaluating vehicle CO_(2) emission.