Abstract

In view of the deliberations on new Euro 7 emission standards to be introduced by 2025, original equipment manufacturers (OEMs) are already hard at work to further minimise the pollutant emissions of their vehicles. A particular challenge in this context will be compliance with new particulate number (PN) limits. It is expected that these will be tightened significantly, especially by including particulates down to 10 nm. This will lead to a substantially increased effort in the calibration of gasoline particulate filter (GPF) control systems. Therefore, it is of great interest to implement advanced methods that enable shortened and at the same time more accurate GPF calibration techniques. In this context, this study presents an innovative GPF calibration procedure that can enable a uniquely efficient development process. In doing so, some calibration work packages involving GPF soot loading and regeneration are transferred to a modern burner test bench. This approach can minimise the costly and time-consuming use of engine test benches for GPF calibration tasks. Accurate characterisation of the particulate emissions produced after a cold start by the target engine in terms of size distribution, morphology, and the following exhaust gas backpressure and burn-off rates of the soot inside the GPF provides the basis for a precise reproduction and validation process on the burner test bench. The burner test bench presented enables the generation of particulates with a geometric mean diameter (GMD) of 35 nm, exactly as they were measured in the exhaust gas of the engine. The elemental composition of the burner particulates also shows strong similarities to the particulates produced by the gasoline engine, which is further confirmed by matching burn-off rates. Furthermore, the exhaust backpressure behaviour can accurately be reproduced over the entire loading range of the GPF. By shifting GPF-related calibration tasks to the burner test bench, total filter loading times can be reduced by up to 93%.

Highlights

  • Up until 2017, the aftertreatment system of a gasoline engine-powered vehicle mostly consisted of a three-way catalytic converter (TWC)

  • Two main solution paths have been followed: the first focuses on advanced engine control strategies aiming at minimising engine-out particulate emissions, and the second, and the most influential, is the introduction of a gasoline particulate filter (GPF)

  • The contour plots for both cold-start measurements at TCoolant = −15 ◦ C depicted in Figure 4, which are representative for all the cold-start measurements conducted in the vehicle, prove the reproducibility of the DMS500 system for measurements executed on, e.g., different weekdays

Read more

Summary

Introduction

Up until 2017, the aftertreatment system of a gasoline engine-powered vehicle mostly consisted of a three-way catalytic converter (TWC). The focus was mainly on reducing gaseous emissions, while little regard was given to particulate matter (PM) emissions. With the introduction of the Euro 6d-TEMP regulations, strict particulate number (PN) limits have been introduced, giving greater weight to PN emissions. OEMs were pushed to develop additional aftertreatment solutions since TWCs alone were no longer sufficient to bring down all pollutant emissions to the extent necessary to comply with the newly established emission standards. Two main solution paths have been followed: the first focuses on advanced engine control strategies aiming at minimising engine-out particulate emissions, and the second, and the most influential, is the introduction of a gasoline particulate filter (GPF). GPFs were first introduced by Daimler and proved to be significantly effective in reducing

Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call