Transient Characteristics of Combustion and Emissions during Start up at Higher Cranking Speed in a PFI Engine for HEV Application

2008-01-2420

10/06/2008

Event
Powertrains, Fuels and Lubricants Meeting
Authors Abstract
Content
The transient characteristics of combustion and emissions during the engine start up at different higher cranking speeds for hybrid electric vehicle (HEV) applications were presented in this paper. Cycle-by-cycle analysis was done for each start up case. Intake air mass during the first several cycles decrease as the engine was cranked at higher speed. Ignition timing is delayed with higher cranking speed, which leads to an increase of exhaust temperature. For various start up cases, similar quantity of fuel is injected at the first cycle, but the ignition timing is significantly delayed to meet the acceleration requirement when cranking speed enhanced. Because of the deterioration of intake charge, the air-fuel mixture is over-enriched in the first several cycles for the cases at higher cranking speed. With cranking speed is increased, the in-cylinder residual gas fraction rises, which leads to poor combustion and decrease of mass fraction of burned fuel.
Meta TagsDetails
DOI
https://doi.org/10.4271/2008-01-2420
Pages
10
Citation
Yu, S., Dong, G., Gao, Y., and Li, L., "Transient Characteristics of Combustion and Emissions during Start up at Higher Cranking Speed in a PFI Engine for HEV Application," SAE Technical Paper 2008-01-2420, 2008, https://doi.org/10.4271/2008-01-2420.
Additional Details
Publisher
Published
Oct 6, 2008
Product Code
2008-01-2420
Content Type
Technical Paper
Language
English