Investigating Particulate and Nitrogen Oxides Emissions of a Plug-In Hybrid Electric Vehicle for a Real-World Driving Scenario

Mario Feinauer,Fabius Epple,Tobias Schripp,Tobias Grein,Simone Ehrenberger

doi:10.3390/app12031404

Mario Feinauer, Fabius Epple + Show 3 more

Open Access

https://doi.org/10.3390/app12031404

Copy DOI

Journal: Applied sciences	Publication Date: Jan 28, 2022
Citations: 17	License type: CC BY 4.0

Affiliation: German Aerospace Center

Abstract

Plug-in hybrid electric vehicles (PHEVs) show a high pollutant emission variability that strongly depends on the operating conditions of the internal combustion engine. Additionally, studies indicate that driving situations outside of the real driving emissions boundary conditions can lead to substantial pollutant emission increases. The objective of this study is to measure and analyze the particulate number (PN) and nitrogen oxides (NOx) emissions of a Euro 6 PHEV for a selected real-world driving test route in the Stuttgart metropolitan area. For this purpose, the vehicle is set out with multiple measurement devices to monitor vehicle internal and external parameters. Particle distribution results show an overall uniform pattern, which allows a comparative analysis of the different test scenarios on the basis of the PN concentration. While the trip-average PN emissions are in good agreement, transient effects during highway driving can substantially increase emissions, whereas the fuel consumption does not necessarily increase in such situations. PN measurements including ultrafine particles (UFP) show a significant increase in urban emissions due to higher cold start emission peaks. Additionally, low ambient temperatures raise the uncertainty of NOx and PN cold start emissions. With regard to future emission regulations, which claim that vehicles need to be as clean as possible in all driving situations, PHEV emission investigations for further situations outside of the current legislations are required.

Highlights

Emissions from passenger car transport play a major role in air quality and climate change
It should be noted that here the actual fuel consumption related to the internal combustion engine (ICE) is shown, which is measured by a fuel mass flow sensor
A Euro 6 Plug-in hybrid electric vehicles (PHEVs) is investigated on particulate number (PN) and nitrogen oxides (NOx) emissions in multiple test drives with variations in ambient conditions and driving mode on a defined real-world driving test route in the city of Stuttgart

Summary

Introduction

Emissions from passenger car transport play a major role in air quality and climate change. Uncertainties remain, as current emission inventories and databases do not capture all these variances and do not represent the actual emissions of all vehicles models or driving situations. This raises the importance of on-road real driving emissions (RDE) testing with portable emissions measurement systems (PEMS). Ref [4] found within their PEMS measurement campaign that the speed-dependent COPERT emission factors underestimate emissions of Euro 6b vehicles by overlooking acceleration events that cause high emission peaks. Laboratory and on-road PEMS measurements of conventional gasoline and diesel Euro 6b vehicles [5] indicate that even for the same fuel type, high deviations of emissions can occur.

Objectives

Methods

Results

Conclusion