| To study the characteristics of nitrogen oxides (NOx) emissions from vehicles in the Yangtze River Delta, this research uses a portable emission measurement system (PEMS), which includes 8 typical urban buses in Shanghai, Hangzhou and Suzhou, including China Ⅲ, Ⅳ diesel buses, and LNG buses. The experimental results show that the NOx emission of diesel buses increases with the increase of speed in steady state, but the NOx emission of LNG bus changes. The fuel emissions of China Ⅲ diesel buses are fluctuating, while China Ⅳ diesel buses and LNG buses show a decrease trend. The NOx of different types of diesel buses are gradually increasing with the increase of VSP, but the LNG buses show the trend of first decrease and then increase. Bus NOx integrated emission factor ranges in 5.0 g/km～19.1 g/km, and the emission factor in 5.1 g/ (kW·h)～15.8 g/ (kW·h). |
