Post on 23-Oct-2021
transcript
Bertold Arlitt
AVL Emission Test Systems GmbH
Confidential
Korrelationen NOx
NO, NO2 und NOx Analyse mit FTIR und CLD FTIR Anwendertreffen 20. September 2018
Bertold Arlitt | AVL ETS | 20 September 2018 | 2Confidential
Note
Bertold Arlitt | AVL ETS | 20 September 2018 | 3Confidential
Vergleichsmessungen CLD vs. SESAM i60 FT Motorenprüfstand
NOx Korrelationen und NO2 Messwertunterschiede bei transienten Test Zyklen
Reaktionskinetik der NO Oxidation zu NO2 [NOx]
Thema NO, NO2 und NOx in Kalibriergasflaschen
Zertifikate und Rückführbarkeit
Vergleichsmessungen NOx Messwert gut Unterschiede beim NO
Probennahme Verunreinigungen durch Ruß
Messwertvergleiche NOx SESAM i60 FT vs. SII / AMA i60 vs. SESAM i60 FT SII
Zusammenfassung
Inhalt
Bertold Arlitt | AVL ETS | 20 September 2018 | 4Confidential
ENGINE DYNAMOMETER TEST CELL
EMISSION TESTING BY FTIR-SPECTROSCOPY
Development Tool for:
• Engine calibration
• Combustion analysis
• Aftertreatment-systems
• Catalyst efficiency test by the use of different sample points.
Certification Instrument:
• EURO VI und China VI: Ammonia NH3
• EPA CFR 1065 / 1066 : Nitrous oxide N2O
• EPA CFR 1065 CNG Engines: NMHC, NMNEHC
• GTR 15 Flex-Fuel Vehicles (E85) HCHO, MeCHO, EtOH
Bertold Arlitt | AVL ETS | 20 September 2018 | 5Confidential
Global Technical Regulation (GTR 15)Emission component measurement
CO2
CO
NOx
THC
CH4
NMHC
PM
PN
Carbon dioxide
Carbon monoxide
Nitrogen oxides
Total hydrocarbons (by FID)
Methane
Non-methane hydrocarbons
Particulate Matter
Particle Number
CVS Bag
CVS Bag
CVS Bag
CVS Bag/Tunnel
CVS Bag
calculated
CVS Tunnel
CVS Tunnel
NDIR
NDIR
CLD, NDUV
FID, HFID
GC-FID, Cutter-FID
PTS
PNC with CPC
FID all fuels except Diesel, HFID all fuels
THC – CH4
NO2
N2O
NH3
Nitrogen dioxide
Ammonia
Calc. / CVS cont.
CVS Bag
Tailpipe
NDUV, QCL, CLD (NOx-NO)
GC–ECD, FTIR, NDIR, QCL-IR,
FTIR, TDLS, QCL
(NOx,Bag – NO,cont.) or NO2,cont.
FTIR, NDIR with <0.1ppm interference
C2H5OH
NMNEOG
HCHO
CH3CHO
Ethanol
Non-Methane Non-Ethanol Organic Gases
Formaldehyde
Acetaldehyde
CVS
calculated
CVS
CVS
Impinger, Photo Acoustic, FTIR
DNPH-HPLC, FTIR
DNPH-HPLC, FTIR
Reference is CARB
Reference is CARB
Reference is CARB
Emission Component Sample Method Measurement Principle Notes
Sta
ndard
Gaseous
PM
/PN
Additio
nal Polluta
nts
Nitrous oxide
Bertold Arlitt | AVL ETS | 20 September 2018 | 6Confidential
RECORDED DATA
• Fast transient concentration changes during turbo-charged diesel engine-out post DOC measurements.
• Extractive sampling system
• 10 Hz Measurement
• FTIR spectrometer scan speed 5Hz
• Synchronous concentration reading between CLD ChemiluminescenceDetector (Analyzer) and FTIR spectroscopic measurement values.
NOX COMPARISON BETWEEN CLD AND FTIR
[ppm]
Time (s)
APPLICATION ENGINE TESTING
• CLD and FTIR (hot/wet)
Bertold Arlitt | AVL ETS | 20 September 2018 | 7Confidential
REGRESSION ANALYSIS OF THE NOx MEASUREMENT COMPARISON
CLA[ppm]
FTIR i60[ppm]
STATISTICAL EVALUATION
• Linear Regression correlation based on 20000 data points of the different analytical measurement principle.
• Validation measurement data with coefficients of determination to indicate of the correlation results between both analyzer.
• Automotive exhaust emission requirements demands the highest precision and accuracy vs. a pretty fast time resolution.
APPLICATION ENGINE TESTING
• Good agreement
Bertold Arlitt | AVL ETS | 20 September 2018 | 8Confidential
NO2 COMPARISON BETWEEN CLD AND FTIR
Overshoot issues of the CLD indirect NOx-NO calculation to NO2
It depends on:
• t between NOx vs. NO channels
• NO/ NOx ratio in the exhaust
• NOx converter efficiency CLD
(CLA)
• Correlations not possible, artificial reporting of NO2
via CLD technique during fast transient exhaust measurements.
Bertold Arlitt | AVL ETS | 20 September 2018 | 9Confidential
• Synchronization duration issues during fast transient test cycles between the two channels.
• t related NOx vs. NO difference
• Wrong CLA NO2 measurements related to time delay and converter related side reactions.
NO2 COMPARISON BETWEEN CLD AND FTIR
Issues of the CLD indirect NOx-NO calculation to NO2
• Correlations not possible artificial reporting of NO2
via CLD technique during fast transient exhaust measurements.
Bertold Arlitt | AVL ETS | 20 September 2018 | 10Confidential
NO2 FTIR I60 SII COMPARE W/ CLD (NOX – NO)
• Synchronization duration issues during fast transient test cycles between the two channels.
• t related NOx vs. NO difference
• Wrong CLD NO2 measurements related to time delay
Issues of the CLA indirect NOx-NO calculation to NO2
• Correlations not possible artificial reporting of NO2
via CLD technique during fast transient exhaust measurements.
[ppm]
Time (s)
• Good results (FTIR)
Bertold Arlitt | AVL ETS | 20 September 2018 | 11Confidential
Vergleichsmessungen CLD vs. SESAM i60 FT Motorenprüfstand
NOx Korrelationen und NO2 Messwertunterschiede bei transienten Test Zyklen
Reaktionskinetik der NO Oxidation zu NO2 [NOx]
Thema NO, NO2 und NOx in Kalibriergasflaschen
Zertifikate und Rückführbarkeit
Vergleichsmessungen NOx Messwert gut Unterschiede beim NO
Probennahme Verunreinigungen durch Ruß
Messwertvergleiche NOx SESAM i60 FT vs. SII / AMA i60 vs. SESAM i60 FT SII
Zusammenfassung
Inhalt
Bertold Arlitt | AVL ETS | 20 September 2018 | 12Confidential
Reaction of NO with Oxygen to NOx
KINETICS OF THE NITRIC OXIDE OXIDATION
NO + 0.5 O2 NO2
Details
• Keywords: Air pollution, nitrogen oxides, kinetics, oxidation.
• Experimental Setup: N2 + NO gas cylinders,oxygen generator, massflow meter and FT-IR(Jaso 4cm-1) spectrometerwith gas cell.
O2
Bertold Arlitt | AVL ETS | 20 September 2018 | 13Confidential
CALIBRATION GAS STABILITY OF NO AND NO2
Stability evaluation of calibration gas mixtures containing both NO and NO2
• NO gas standard in nitrogen is stabile
• NO2 gas standard only in air is stabile
• NOx gas standards in nitrogen
Bertold Arlitt | AVL ETS | 20 September 2018 | 15Confidential
Calibration Gas NO or NOx Traceability
• Total Oxides of nitrogen (NOx) in nitrogen, 100 µmol/mol - We prepare 100 µmol/mol of nitric oxide in nitrogen. On the certificate there will be value of NO with 0.3 % rel. uncertainty and as an additional information we can add information about amount of NO2 in the mixture. This certificate would include accreditation recognition.
• Air Liquide order from Scott with traceable to VSL (Netherlands) with reference to NIST.
• But the calibration gas NOx value on gas analysis certificates is not certificated!
2
Bertold Arlitt | AVL ETS | 20 September 2018 | 16Confidential
Vergleichsmessungen CLD vs. SESAM i60 FT Motorenprüfstand
NOx Korrelationen und NO2 Messwertunterschiede bei transienten Test Zyklen
Reaktionskinetik der NO Oxidation zu NO2 [NOx]
Thema NO, NO2 und NOx in Kalibriergasflaschen
Zertifikate und Rückführbarkeit
Vergleichsmessungen NOx Messwert gut Unterschiede beim NO
Probennahme Verunreinigungen durch Ruß
Messwertvergleiche NOx SESAM i60 FT vs. SII / AMA i60 vs. SESAM i60 FT SII
Zusammenfassung
Inhalt
Bertold Arlitt | AVL ETS | 20 September 2018 | 17Confidential
NOX CORRELATION CLA WITH FTIR
• Good agreement
SOOT CONTAMINATION ISSUE IN SAMPLE–LINE AND –FILTER.
• No difference in NOx
Bertold Arlitt | AVL ETS | 20 September 2018 | 18Confidential
Differences in NO peaks
NO Correlation CLD with FTIR (issues)
• Partly higher NO concentrationspeaks over test cycle as reaction of NO2 with soot contamination.
SOOT CONTAMINATION ISSUE IN SAMPLE–LINE AND –FILTER
Bertold Arlitt | AVL ETS | 20 September 2018 | 19Confidential
NO2 CORRELATION CLD WITH FTIR (ISSUES)
• Differences in NO2 peaks
• NO2 Loss Effect on Soot
SOOT CONTAMINATION ISSUE IN SAMPLE–LINE AND –FILTER.
• Partly lower NO2 concentrationspeaks over test cycle as reaction of NO2 with soot contamination.
2
2
Bertold Arlitt | AVL ETS | 20 September 2018 | 20Confidential
SESAM I60 SII COMPARE TO SESAM I60 FT
• Lower noise at 5Hz measurement
• Better data signal processing
• Better low range measurement
• Better detection limits
IMPROVEMENTS SESAM i60 FT SIICOMPARISON NOx CONCENTRATION READING
Bertold Arlitt | AVL ETS | 20 September 2018 | 21Confidential
NOX SESAM I60 FT SII COMPARE AMA I60
Time (s)
[ppm]
• WLTC recording tail pipe
• Good Conc. comparison
• Better low range measurement
• Better detection limits
IMPROVEMENTS SESAM i60 FT SII
Engine OFF * Engine OFF *
*Engine off = No exhaust flow rate
Bertold Arlitt | AVL ETS | 20 September 2018 | 22Confidential
NOX SESAM I60 SII / CLD I60 COMPARE
REGRESSION ANALYSIS OF THE NOx MEASUREMENT COMPARISON
• STATISTICAL EVALUATION
• WLTC recording tail pipe
• Good correlation over full range
• Good dynamic range
• High R2 values low offset
CLD i60[ppm]
FTIR i60[ppm]
Bertold Arlitt | AVL ETS | 20 September 2018 | 23Confidential
Vergleichsmessungen CLD vs. SESAM i60 FT Motorenprüfstand
NOx Korrelationen und NO2 Messwertunterschiede bei transienten Test Zyklen
Reaktionskinetik der NO Oxidation zu NO2 [NOx]
Thema NO, NO2 und NOx in Kalibriergasflaschen
Zertifikate und Rückführbarkeit
Vergleichsmessungen NOx Messwert gut Unterschiede beim NO
Probennahme Verunreinigungen durch Ruß
Messwertvergleiche NOx SESAM i60 FT vs. SII / AMA i60 vs. SESAM i60 FT SII
Zusammenfassung
Inhalt
Bertold Arlitt | AVL ETS | 20 September 2018 | 24Confidential
ANALYSIS FTIR AND CLD - NO, NO2 AND NOX
Zusammenfassung
• In general the correlation measurements between SESAM i60 FT SII vs. conventional analyzer benchesagree to each other very well.
• NOx correlations between CLD and FTIR show good results, depending on the used CLD with related H2O and CO2 quench differences.
• NOx NO and NO2 measurements could be affected by sample-line, -filter soot contamination issues.
• The NOx value on calibration gases is not a certified, related to instabilities of NO2 in nitrogen mixtures.
• NO2 gas in only stable in synthetic air and NO in only stable in nitrogen.
• Usually the NOx correlations between CLD and FTIR by the use of proper procedure should agree +3% in between different test cycles.
www.avl.com
Thank You