Modelling of cold start excess emissions for passenger cars

Jean-Marc André (1) , Robert Joumard (1)

1 INRETS/LTE - Laboratoire Transport et Environnement

After a survey among 39 European laboratories, data were obtained concerning 1 766 vehicles and 35 941 measurements (1 measurement corresponds to 1 vehicle, 1 cycle and 1 pollutant). Data were measured during standardised and representative cycles. The data received were analysed in order to model cold-start-related excess emissions (defined as the difference between cold and hot emissions, for a same cycle) for 4 regulated pollutants (CO, CO2, HC, NOx) and 116 unregulated pollutants as a function of various parameters: technology or emission standard, average speed, ambient temperature and travelled distance. In the second time, the model is wide from a single trip to a traffic of vehicles, characterized by the parameters traffic flow, overall traffic mean speed and environmental conditions. One uses for that of the statistical distributions, resulting from measurements, which relate the mean speed during the cold period to the overall traffic mean speed, the ambient temperature, and the distribution of mileage during the cold period according to the length of the trip, the cold start number per hour as well as the distribution of mileage after a given stop duration at a given hour. One obtains a simple model expressing a cold unit excess emission in g/km, function of mean speed, ambient temperature, hour and season. This model is provided for the current gasoline and diesel cars. The final model is included in the ARTEMIS emissions inventory model.

Mots clés: Transport; emission; pollutant; cold start; driving cycle; catalyst; diesel; passenger car; ambient temperature; engine temperature; model; speed; travelled distance

Domaines: Sciences de l'environnement

Jean-Marc André, Robert Joumard. Modelling of cold start excess emissions for passenger cars. 2005. ⟨hal-00917071⟩