Green Traffic-Oriented Heavy-Duty Vehicle Emission Characteristics of China VI Based on Portable Emission Measurement Systems

With a continuous increase in vehicle ownership, vehicle emissions have become one of the main sources of air pollution in China. Serious air pollution is a great threat to human health and life. The China VI regulations, which adopt strict particulate matter (PM) and nitrogen oxide (NOx) limitations, have been implemented. As one of the best technologies for measuring vehicle emissions, portable emission measurement systems (PEMSs) have gained attention. In this work, the characteristics of China VI heavy-duty vehicle emissions were investigated with a PEMS. The effects of road conditions on NOx, hydrocarbon (HC), carbon monoxide (CO), PM and particle number (PN) pollutants were analyzed based on distance-based emission factors. The results show that the gaseous pollutant levels of NOx, HC and CO for China VI vehicles are much lower than those for China V vehicles. The average distance-based emission factors of NOx CO and HC decreased by 88%, 98%, and 62.7%, respectively. Based on the power-based window method, the PEMS test results for NOx, HC and CO are 460 mg.(kWh) 1, 192 mg.(kWh) 1 and 37.5 mg.(kWh)(-1), respectively. According to the PEMS tests, approximately 88%-95% of the particles are in the 10-100 nm class based on three typical operational modes, which represent approximately 0.08%-0.13% of the total particle mass. These heavy-duty vehicles can satisfy the requirements of the PEMS China VI standards. This study emphasizes the importance of obtaining real-world measurements of heavy-duty vehicles to improve the accuracy of emission factors in the development of emission inventories in China.