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Determining how close the A/F ratio is to the stoichometric point using exhaust gas analysis. Presented to East Bay ATA, Hayward, CA May 5, 2004 By: Robert.

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Presentation on theme: "Determining how close the A/F ratio is to the stoichometric point using exhaust gas analysis. Presented to East Bay ATA, Hayward, CA May 5, 2004 By: Robert."— Presentation transcript:

1 Determining how close the A/F ratio is to the stoichometric point using exhaust gas analysis. Presented to East Bay ATA, Hayward, CA May 5, 2004 By: Robert J. Schrader President, Bridge Analyzers, Inc.

2 Lambda is Oxygen Balance

3 Lambda control is necessary for peak combustion efficiency in the Engine. Lambda control is necessary for peak CAT efficiency. Lambda Control Improves Reliability, Fuel Economy and Lowers Emissions.

4 Engine out CE for Gasoline Fuel is no better than 95%. Tailpipe-out CE for CAT equipped vehicles improves to 99.0-99.5%. Factor of 10 improvement Required for Current Emission Standards CAT CE is very Lambda-Dependent

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8 NOx Reduction Bed Requires Lambda to be not greater than 1.020. CO/HC Oxidation Bed Requires Lambda to be not less than 0.980. Modulation Depth Cycles Rich and Lean Between the Limits Above.

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10 Lambda = 1.000 when the Oxygen available and Combustible Oxygen demands are in balance. This is the point of perfect stoichometric balance. At this point the A/F ratio is 14.71 to 1.00 for Gasoline. Thus, A/F = 14.71 x Lambda

11 Brettschneider Lambda uses all the oxygen- bearing and combustible-bearing gases. Balance Equation - Calculation not affected by the degree of oxidation. Method is insensitive to combustion efficiency. Either Pre-CAT or Post-CAT gases may be used.

12 = 1.000 when Oxygen available and Combustible demands are in balance. ECM controls =1.000 at 0.5-1.0 Cycles/Sec using lambda sensor input. 3-Way CAT operation requires 0.980 to 1.020 Lambda can be confirmed by exhaust gas measurement, either pre or post CAT.

13 calculated from exhaust gas indicates air-fuel mixture independent of the engine controls. calculated from exhaust gas indicates air-fuel mixture independent of combustion efficiency. Cold (Open Loop) vs Hot (Closed Loop) vs CAT light-off operation can be evaluated. can be used to tune systems which do not have closed-loop control.

14 High Combustion Efficiency: Measure O2 post CAT - every 5% air leak adds 1.0% O2 to gases. Low Combustion Efficiency: Add CO and CO2 - should equal 15% for Gasoline. Compare both Methods. If O2 indicates air dilution - then confirm this with low CO and CO2 sum. They should agree.

15 Created by iATN Tech Support staff, and available to iATN members on-line at http://members.iatn.net/tech/lambda.ht ml Plug and Play either 4 or 5 gas values. Can select either US or European gasoline constants. Operates in Java - can be saved and run off-line by any Java-equipped net browser.

16 Available as email attached Excel file by contacting: support@bridgeanalyzers.com Plug and Play either 4 or 5 gas values. Can select either US or European gasoline constants. Operates on any PC with Excel - can be saved and run off-line using Microsoft Excel.

17 Written by Miles Wada using the Brettschneider equation - ala Bridge. Available for download at: http://www.aeswave.com/

18 Written by Greg Meyer using the Brettschneider equation - ala Bridge. Available from Greg via email at: gsmeyer@attbi.com Operates on Microsoft PC in Excel.

19 A/F = 14.71 x Lambda

20 September 1993 Mazda Protege 1.8L, Manual Trans, No EGR Failed Smog Check for Timing (FA99), GP HC & NO x

21 ASM 5015 ResultHCCOCO2NOO2RPM GP2470.4913.820001.21624 Standards HCCOCO2NOO2 Fail920.55716 GP2812.051,961 AVG210.06150

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23 November 1993 Mazda Protege 1.8L, Manual Trans, No EGR Failed its Pre-repair Baseline Inspection at a CAP station for for Timing (FB48), HC & NO x

24 ASM 5015 ResultHCCOCO2NOO2RPM Fail1860.4316109511683 Standards HCCOCO2NOO2 Fail920.55716 GP2812.051,961 AVG210.06150

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26 December 1993 Mazda Protege 1.8L, Manual Trans, No EGR Passed & Certified

27 ASM 5015 ResultHCCOCO2NOO2RPM Pass740.2115.53080.081590 Standards HCCOCO2NOO2 Fail920.55716 GP2812.051,961 AVG210.06150

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