Browse Publications Technical Papers 2005-01-3866
2005-10-24

Carbon Canister-Based Vapor Management System to Reduce Cold-Start Hydrocarbon Emissions 2005-01-3866

Engine out (feedgas) emissions control during cold start operations has been a major technical challenge since mandated LEV/ULEV/SULEV/PZEV regulation compliance. Cold start emissions contribute to more than 85% of total emissions in a FTP test. Unburned Hydrocarbons are mostly generated during cold starts due to a rich Air/fuel ratio strategy. Cold intake and cylinder wall surfaces do not provide a quick vaporization bed for the rich fuel, therefore un-vaporized and unburned fuel result in excessive tailpipe emissions. Utilizing fuel vapor during cold starts reduces the Hydrocarbon (HC) emissions level and minimizes the transient fuel effect process.
A vapor management system must function to control the Air-to-fuel ratio of the intake charge during “cold-starts”, idle, and drive-away, or until catalyst lights off to a desired level. Additionally, vapor fuelling can provide solutions to the inherent problems of “cold fuel enrichment”, “wall wetting”, “lost-fuel”, and “mixture preparation”, as well as, open up beneficial opportunities for lean air-fuel ratio cold starts.
A Vapor Management control System consisting of a Carbon Canister vapor source, supplying a traditional induction system augmented with additional subsystems in a preferred configuration, has been designed and tested, and the results presented in this paper. A major reduction in HC emissions over liquid port injection (PFI) is achieved.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Transient Characteristics of Cold Start Emissions from a Two-Stage Direct Injection Gasoline Engines Employing the Total Stoichiometric Ratio and Local Rich Mixture Start-up Strategy

2012-01-1068

View Details

TECHNICAL PAPER

LEV II Applications Based on a Lean Start Calibration

2001-01-1311

View Details

JOURNAL ARTICLE

A Novel Singular Perturbation Technique for Model-Based Control of Cold Start Hydrocarbon Emission

2014-01-1547

View Details

X