Real-Time Evaporative Emissions Measurement: Mid-Morning Commute and Partial Diurnal Events Sierra Research, Incorporated

Format:

Conference/Event

Author/Creator:

Delaney, Siona S., author.

Conference Name:

International Fuels and Lubricants Meeting and Exposition (2000-10-16 : Baltimore, Maryland, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2000

Summary:

Real-time evaporative emissions test data were obtained for thirty-six 1977 to 1989 model year vehicles under conditions representative of a California mid-morning commute. The test procedure involved a cold soak followed by a driving event using the LA92 cycle, followed by a hot soak at 75°F and then a diurnal event where the ambient temperature was increased from 75 to 84°F over six hours. Ambient temperature then decreased from 84°F to 60°F over the next 13 hours and then was increased from 60°F to 75°F over the final five hours of the test.Overall, the test results could generally be described by three types of responses:In general, vehicles that failed an inspection and maintenance (I/M) type canister purge test tended to exhibit the first response, while vehicles that failed an I/M-type evaporative system pressure test tended to exhibit the second response. As expected, vehicles passing both types of I/M tests and gas cap pressure tests tended to exhibit the third response, and had low hot soak and diurnal emissions.The real-time evaporative emissions data obtained from the nineteen 1980-1985 model year vehicles in the 36-vehicle fleet were compared with emission predictions from draft versions of the evaporative emissions algorithms of EPA's MOBILE6 and CARB's EMFAC2000 models. This comparison indicates that, for the 19-vehicle fleet, both models underestimated the magnitude and duration of hot soak emissions. In contrast, both models overestimated the magnitude of partial-day diurnal emissions for the same fleet. Further, a comparison of model results with data representative of a mid-morning commute indicates that MOBILE6 underpredicted emissions from the 19 vehicles while EMFAC2000 overpredicted emissions

Notes:

Vendor supplied data

Publisher Number:

2000-01-2959

Access Restriction:

Restricted for use by site license