Gasoline Particulate Filter Technology for China6b with RDE

Mychal  Taylor, NGK Insulators, Ltd.

Global emission regulations are continually being tightened with the Chinese regulations becoming even stricter. In particular, RDE testing is scheduled to be officially introduced for China 6b regulations from 2023 onwards. The RDE test will require a wider range of vehicle speed and acceleration than the current WLTC test cycle causing, PN emissions from vehicles to increase. The upcoming Chinese regulation will also consider expanding the test condition to include higher altitudes than the current European RDE test leading to PN emissions increasing from an environmental point of view.

Understanding the effects of RDE test’s environment, driving conditions, and GPF installation on the tail pipe PN emissions is important for the future development of engines and emission systems that include a GPF. However, the impact of environmental conditions on PN emission during RDE testing with an emission system with a GPF is limited.

In order to evaluate the effectiveness of the RDE test’s environment, driving conditions, and GPF installation on the tail pipe PN emissions in China, driving routes in China were selected that provided differences in temperature, altitude, and driving severity to investigate how the environmental and driving conditions impacted PN emission. It is estimated that the influence of the driving severity on the tailpipe PN emission is larger than environmental severity such as altitude and temperature.

The evaluation results show that installing a GPF has the potential to pass PN regulation for China 6b regulations, even under extreme driving and environmental conditions such as aggressive driving, high altitude, and low temperatures in China.