Lin Cherng-Yuan, Chen Lih-Wei, Wang Li-Ting
Department of Marine Engineering, National Taiwan Ocean University, Keelung, 20224, Taiwan, ROC.
Environ Monit Assess. 2006 May;116(1-3):291-305. doi: 10.1007/s10661-006-7402-2.
Diesel vehicles are one of the major forms of transportation, especially in metropolitan regions. However, air pollution released from diesel vehicles causes serious damage to both human health and the environment, and as a result is of great public concern. Nitrogen oxides and black smoke are two significant emissions from diesel engines. Understanding the correlation between these two emissions is an important step toward developing the technology for an appropriate strategy to control or eliminate them. This study field-tested 185 diesel vehicles at an engine dynamometer station for their black smoke reflectivity and nitrogen oxides concentration to explore the correlation between these two pollutants. The test results revealed that most of the tested diesel vehicles emitted black smoke with low reflectivity and produced low nitrogen oxides concentration. The age of the tested vehicles has a significant influence on the NOx emission. The older the tested vehicles, the higher the NOx concentrations emitted, however, there was no obvious correlation between the age of the tested diesel vehicles and the black smoke reflectivity. In addition, if the make and engine displacement volume of the tested diesel vehicles are not taken into consideration, then the correlation between the black smoke reflectivity and nitrogen oxides emission weakens. However, when the tested vehicles were classified into various groups based on their makes and engine displacement volumes, then the make of a tested vehicle became a dominant factor for both the quantity and the trend of the black smoke reflectivity, as well as the NOx emission. Higher emission indices of black smoke reflectivity and nitrogen oxides were observed if the diesel vehicles were operated at low engine speed and full engine load conditions. Moreover, the larger the displacement volume of the engine of the tested vehicle, the lower the emission indices of both black smoke reflectivity and nitrogen oxides emitted. The emission indices of black smokes reflectivity and nitrogen oxides emission of the tested diesel vehicles were also influenced by the make of the vehicle. It was observed that the emission indices of black smoke reflectivity decreased nearly linearly with the increase of the emission indices of NOx for the tested vehicles belonging to the same group of make and engine displacement volume.
柴油车辆是主要的交通方式之一，尤其是在大都市地区。然而，柴油车辆排放的空气污染对人类健康和环境都造成了严重损害，因此备受公众关注。氮氧化物和黑烟是柴油发动机的两种重要排放物。了解这两种排放物之间的相关性是开发控制或消除它们的适当策略技术的重要一步。本研究在发动机测功机站对185辆柴油车辆进行了实地测试，测量其黑烟反射率和氮氧化物浓度，以探索这两种污染物之间的相关性。测试结果表明，大多数被测柴油车辆排放的黑烟反射率较低，氮氧化物浓度也较低。被测车辆的使用年限对氮氧化物排放有显著影响。被测车辆越旧，排放的氮氧化物浓度越高，然而，被测柴油车辆的使用年限与黑烟反射率之间没有明显的相关性。此外，如果不考虑被测柴油车辆的品牌和发动机排量，那么黑烟反射率与氮氧化物排放之间的相关性就会减弱。但是，当根据被测车辆的品牌和发动机排量将其分为不同组时，被测车辆的品牌就成为了黑烟反射率的数量和趋势以及氮氧化物排放的主导因素。如果柴油车辆在低发动机转速和全发动机负荷条件下运行，则会观察到黑烟反射率和氮氧化物的排放指数较高。此外，被测车辆发动机的排量越大，排放的黑烟反射率和氮氧化物的排放指数就越低。被测柴油车辆的黑烟反射率和氮氧化物排放指数也受车辆品牌的影响。观察到，对于属于同一品牌和发动机排量组的被测车辆，黑烟反射率的排放指数随着氮氧化物排放指数的增加而几乎呈线性下降。
