On road NOx and Ultrafine Particle Emission Characteristics of China IV Diesel Bus in Shanghai

Abstract:

The on road emission test of a China Ⅳ diesel bus was conducted on some specific roads of Shanghai to study the real world emission characteristics of NOx and ultrafine particle. The results show that the test bus has an average speed of 20.59 km·h-1, and NOx and ultrafine particle number emission factors are 9.33 g·（km·vehicle)-1 and 5.78×1014particles (km·vehicle)-1, respectively. The on road NOx emissions mainly concentrate at middle high speed (>35~55 km·h-1) and large acceleration (a>0.5 m·s-2) driving conditions, and ultrafine particle emissions concentrate at middle high speed (v>40 km·h-1) and large acceleration driving conditions. During acceleration mode, the emission rates of NOx and ultrafine particle number are relatively high. Ultrafine particle number emission rates of four driving modes vary obviously when the particle size is smaller than 100 nm.