This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Convenient Technique for Determining Two-Stroke Emission Measurement Accuracy and A/F Ratio
Annotation ability available
Sector:
Language:
English
Abstract
This paper describes a method of using the total emission concept for conveniently assessing the accuracy of emission measurements. The measured total HC emissions are treated as unburned fuel (C8 basis) plus burning zone HC (C1 basis). Statistical analysis shows that the emission test data may be questionable if the total emission calculation exceeds the range of 100 +/- 2σ*. This paper also describes a technique to determine the Air to Fuel (A/F) ratio for two-stoke engines. This method may be used to calculate the overall A/F and burning zone A/F for DI two-stroke engines and for engines using oxygenated fuel.
Twenty-five OMC engines have been tested by following EPA emission test procedure. The total emission and A/F analysis for these tests indicate that the new method is a very useful tool for assessing A/F and the accuracy of emission measurements. This technique reduces the emission test errors and shortens engine calibration and development time.
Recommended Content
Authors
Topic
Citation
Xu, R., "A Convenient Technique for Determining Two-Stroke Emission Measurement Accuracy and A/F Ratio," SAE Technical Paper 961804, 1996, https://doi.org/10.4271/961804.Also In
Design, Modeling, and Emission Control for Small Two- and Four-Stroke Engines
Number: SP-1195; Published: 1996-08-01
Number: SP-1195; Published: 1996-08-01
References
- US EPA, NPRM “Emission Standards for New Gasoline Spark-Ignition and Diesel-Compression Marine Engines” 1995
- Douglas, Roy “AFR and Emissions Calculation from Two-Stroke Cycle Engines” SAE Paper 901599 1990
- Spindt, R.S. “Air/Fuel Ratios from Exhaust Gas Analysis” SAE Paper 650507 1965
- SAE Recommended Practice J-1088 “Test Procedure for the Measurement of Exhaust Emission from Small Utility Engine” 1983
- Stivender, L. Donald “Development of a Fuel-Based Mass Emission Measurement Procedure” SAE Paper 710604 1971
- Fukul, T. Tamura, Y. Omori, S Saltoh, S. “Accuracy of A/F Calculation from Exhaust Gas Composition of SI Engines” SAE Paper 891971 1989
- Eltinge, L. “Fuel/Air Ratio and Distribution from Exhaust Gas Composition” SAE Paper 680114 1968
- Coates, S.W. Lassanske G.G. “Measurement and Analysis of Gaseous Exhaust Emissions From Recreational and Small Commercial Marine Craft” SAE Paper 901597 1990
- Watson, W. “On the Thermal and Combustion Efficiency of a Four-Cylinder Petrol Motor” Proc. I. Auto. E. 2 1908
- Heywood, J.B. “Internal Combustion Engine Fundamentals” McGraw-Hill Book
- Uyehara, O.A. “Effect of Burning Zone A/F, Fuel H/C on Soot Formation and Thermal Efficiency,” SAE Paper 800093 1980