Development of a standard for the measurement of nonvolatile PM mass and number concentration for use in aircraft engine certification

Transcription

1 Development of a standard for the measurement of nonvolatile PM mass and number concentration for use in aircraft engine certification Greg Smallwood Metrology for Industry and Society 2016 CREATE-AAP Symposium on Atmospheric PM Research 09 February 2016 Vancouver, BC

2 Outline Background Regulatory and Technical Challenges Measurement Campaigns AAFEX-II A-PRIDE 4 A-PRIDE 5 MANTRA Summary and Status 2

3 Background Current regulation on particulates is Smoke Number, to limit visible emissions which has been effective in reducing visible emissions from 1960 s to present 3

4 Objective The development of an aircraft engine non-volatile particulate matter (nvpm) emissions standard is following two of ICAO s environmental goals to develop, adopt, and promote new measures to limit and to reduce the impact of civil aviation aircraft emissions on local air quality the global climate First new emissions standard in more than four decades gaseous emissions (HC, CO, NOx) and smoke number (SN) standards developed in 1970s smoke emissions under regulatory control since 1983 when the ICAO smoke number (SN) regulation was introduced in Annex 16 of the Chicago Convention 4

5 Engine Testing is Expensive Large facilities handle 1000 m3/s airflow pumped through engines Engines costing $35-70M Fuel flow of up to 1 L/s Results in costs of ~ $150k/hr to evaluate SAE E-31 nvpm measurement system, experiments piggy-backed on existing testing AAFEX-II alternate aviation fuels experiment SR Technics engine overhaul and maintenance facility perform experiments while they are re-commissioning engines dedicated engine testing on small to mid-size engines A-PRIDE 4, 5 & 8, VARIAnT 1 & 2, MANTRA 5

6 Co-Development of a New Emissions Certification Requirement Regulatory Development Technical Development International Civil Aviation Organization (ICAO) Society for Automotive Engineers (SAE) Committee on Aviation Environmental Protection (CAEP) SAE E-31 Aircraft Exhaust Emissions Measurement Committee Working Group 3 Emissions Technical (WG3) Particle Matter Subcommittee Particulate Matter Task Group (PMTG) Membership Regulators from Member States Industry Associations Non-Governmental Organizations airport, airline, environmental groups 6 Sampling Team Mass Team Number Team Calculation Team Membership Individuals as technical experts from industry, university, government

7 Co-Development of a New Emissions Certification Requirement Regulatory Development Technical Development International Civil Aviation Organization (ICAO) Society for Automotive Engineers (SAE) Committee on Aviation Environmental Protection (CAEP) SAE E-31 Aircraft Exhaust Emissions Measurement Committee Working Group 3 Emissions Technical (WG3) Particle Matter Subcommittee Particulate Matter Task Group (PMTG) Sampling Team Mass Team Number Team Calculation Team Remit from CAEP to SAE E-31: Develop nvpm Aerospace Recommended Practice (ARP) for Mass & Number 7

8 Particulate Matter Emissions Terms Nonvolatile Primary Particle 10 nm Volatile Coating on a Nonvolatile Aggregate Particle Volatile Nucleation Mode Particle Nonvolatile Aggregate Particle PM is all particulate matter, regardless of phase PM2.5 is all PM with a size less than 2.5 µm great uncertainty in measurements, especially of number, due to volatiles Nonvolatile particulate matter (nvpm) defined by SAE E-31 as PM that does not evaporate at a temperature of 350 C nvpm soot black carbon elemental carbon refractory carbon 8

9 SAE E-31 ARP and CAEP Certification Requirement and Standard Development Contributing Organizations Regulators EASA, CAA, FAA, FOCA, TC, EPA Engine Manufacturers General Electric (US) Pratt & Whitney (Can & US) Rolls-Royce (UK) SNECMA Researchers NRC, Empa, AEDC, EPA,USAF, DLR, NASA,... Cardiff University, Missouri Science & Technology, ETH Zurich,... Aerodyne, Artium Technologies, AVL 9 Measurement Instruments Mass gravimetric filter EC/OC filter TOT Artium LII 300 SuperMAAP AVL MSS Number CPC butanol and water-based 3, 7, 10, 23 nm d50 cutoffs Other SMPS DMS 500, EEPS, FMPS AMS CAPS, CAPS PMSSA

10 nvpm Methodology Standard Campaigns AAFEX Alternate Aviation Fuel EXperiments SAMPLE Studying, sampling and Measuring of aircraft ParticuLate Emissions A-PRIDE Aviation Particle Regulatory Instrumentation Demonstration Experiments VARIAnT VAriable Response In Aircraft nvpm Testing MANTRA Mass Assessment of nvpm Technology Readiness for Aviation 10

11 nvpm Methodology Standard Campaigns and Milestones APEX 2 AIR5892 (nvpm measurement techniques) published APEX 3 Interim JSF Regulators become E31 members EASA Le-er to E31 Aug 2007 Sugges;on of nonvola;le mass ARP by 2010 Joint regulator le-er to E31 May 2008 Task E31 for an ARP for total mass by 2010 Face-to-face mee?ng Oct 2008 Between regulators and SAE E31 AAFE X SAMPLE I AIR6037 (Aircraft nvpm method development) published SAMPLE II MS&T lab testin g EPA testin g Joint regulator presenta?on Nov 2009 Task E31 for Non-vola;le PM ARP by end of 2011 Figure courtesy of Cardiff GTRC 11

12 nvpm Methodology Standard Campaigns and Milestones Figure courtesy of Cardiff GTRC 12

13 SAE E-31 ARP and CAEP Certification Requirement and Standard Development Basic Principles standardize system as much as possible compatible with existing gaseous and smoke number measurement to degree possible minimize particle losses accommodate all engines, from largest turbofans to small helicopter engines and auxiliary power units (APUs) 13

14 Initial SAE E-31 Sampling System Concept Spill with adjustable valve to control inlet pressure to dilution system P1 = 13 to 20 PSI Split for downstream dilution to occur as soon as practically possible (max residence time 3s or max 8m for Annex 16 section) Gas Analysis Existing Annex 16 system T =160 C Smoke Isolation valve (for leak check) Probe conforming to Annex 16 Spill P1 Minimum 20L/min flow Carbon loaded PTFE ID 7 to 8 mm, 60C Eductor DR = 8:1 to 12:1 60C N2 at 2 bar SS ID 7 to 8mm, 60C from splitter onwards P2 & P3 ~ ambient P Non - vola3le Number system VPR PM mass measurement system Non -vola3le Mass system CO2 LII or MAAP Cyclone CPC P2 14 PM number measurement system CO2 P3 Max 7s residence time from probe tip to number/mass system inlets Number and mass systems to be tightly defined by ARP to give minimum particulate losses

15 AAFEX-II DC-8 Aircraft with CFM-2C Engines at Dryden Air Operations Facility 15

16 AAFEX-II 16

17 AAFEX-II Number Measurement Mar 31, JP8 Mar 31, blend Higher particle number measured upstream of VPR compared to downstream CPCs with lower size cut point report higher particle number counts Increase in particle number at low engine power corresponds to CPCs cut point and suggests that volatile particles are contributing to the total number count 17

18 AAFEX-II Fuel Effects 10,000 1.E+00 SAE E in SAE E in nvpm mass (μg/m3) 100 JP-8 HRJ/JP-8 10 F-T + THT 1 nvpm mass EI (g/kgfuel) 1.E-01 1,000 1.E-02 1.E-03 JP-8 HRJ/JP-8 1.E-04 F-T + THT 1.E Engine Power (%) Engine Power (%) F-T + THT and HRJ fuels both have substantially reduced nvpm mass, whether considered on a mass concentration or an EI basis 18

19 Summary from AAFEX-II Experiments E-31 concept sampling system was promising - no show stoppers were identified The effect of downstream dilution on the measurement of particle number was tractable similar results were obtained from both sample trains for number and mass Volatile particle removal will be required to specify a lower size cut off <23nm 19

20 A-PRIDE 4 Experiments at SR Technics Goal was to compare two sampling systems created to near E-31 ARP specifications two suites of measurement instruments, which easily switched back and forth between the two sampling systems compare ability to get same result with two suites of comparable instruments and two sampling systems investigate losses investigate overall system repeatability 20

21 A-PRIDE 4 System Configuration (draft ARP + ancillary instruments) PUMP CO2 1 LPM FOCA/EMPA PM Line 1 LPM APC MFC 2 LPM 5 LPM DMS500 PUMP SP-AMS 25 LPM 60 C 4 LPM CPMA 5 LPM MSS LII Super MAAP PUMP MST 25 LPM DMS500 1 LPM MFC 2 LPM PM Line 60 C PUMP AMS CPMA 4 LPM 5 LPM LII 60 C Ambient 21 1 LPM APC 5 LPM CO2 MSS 16 LPM MAAP 9 LPM

22 A-PRIDE 4 at SR Technics 22

23 A-PRIDE 4 at SR Technics 23

24 A-PRIDE 4 at SR Technics 24

25 A-PRIDE 4 Results Comparing Mass LII Hz Data 400 LII 300N 1 Hz Data - Suite 1 LII 300H 1-Hz Data - Suite 2 Mass Concentration (µg/m3) % Power Cruise 200 Idle 85% Power 150 Background 100 Zero Check 65% Power :30 10:45 11:00 11:15 Clock Time 25 11:30 11:45 12:00

26 A-PRIDE 4 Results Near Detection Limit for Mass LII Hz Data 10 LII 300N 10 Hz Data - Suite 1 9 LII 300H 10-Hz Data - Suite 2 Mass Concentration (µg/m3) :50 13:55 14:00 Clock Time 26 14:05 14:10

27 PM Mass Overall (Primary mass instruments) 27

28 PM Number Overall (PCRF corrected) 28

29 Summary from A-PRIDE 4 Experiments Engine experiments are time-consuming, difficult, and expensive repeatability is difficult to achieve challenging to compare measurements instrument variability sampling system variability engine variability consistent results must be achieved to meet ICAO and engine manufacturer requirements system agreement in terms of PM number was ~5% and PM mass was ~ 1% Subsequently documented and balloted a technical report Procedure for the Continuous Sampling and Measurement of NonVolatile Particle Emissions from Aircraft Turbine Engines (SAE AIR 6241) 29

30 Final Design of Standardized System 30

31 A-PRIDE 5 AIR6241 reproducibility Comparison of three AIR6241 compliant systems Swiss/EMPA European fixed system US/MST North American mobile system EU/SAMPLE III European mobile system First dedicated engine tests 35 participants, 95 hours of dedicated engine operation, and more than 130 tons jet fuel burned 31

32 A-PRIDE 5 System Configuration LII Annex 16 Line PUMP CPMA APC EMPA MFC Gas PM Line Dump Line CO2 PUMP ETH/PSI instruments LII MSS PUMP Annex 16 Line APC PUMP Probe MST MFC PM Line MSS APC CO2 MFC PM Line 32 CO2 PUMP DMS500 MSS Dump Line EMPA CAPS LII PUMP Annex 16 Line LII MST DMS500 AMS Dump Line SAMPLE III PUMP CO2 SAMPLE III NRC Ancillary

33 A-PRIDE 5/SAMPLE III.3 Instrument Suites 33

34 Mass Instrument Calibration Procedures Calibration previous results were based on manufactures calibration mass instruments will be calibrated with TOT EC procedure based on NIOSH 5040 (comparison to mass of EC collected on a filter) requires source of soot that is >80% EC Annual Calibration requires 3 repeats each at 0, 100, 250, and 500 µg/m3 Type Certification requires 6 repeats each at 0, 50, 100, 500, and 1000 µg/m3 Note: Number instruments calibrated per ISO

35 Calibration Setup - NRC NIOSH 5040 filter collection Dual filter in AIR 6241 holder Pump Mass Flow Controller Dump flow Production of nvpm Splitting Mass Flow Controller Pump Mass measurement Inverted Flame Burner Multistage dilution cyclone cyclone HEPA Make-up air Mass Concentration Instrument to be Calibrated Mass Flow Controller Pump Mass Concentration Instrument to be Calibrated Mass Flow Controller Pump Mass Concentration Instrument to be Calibrated Mass Flow Controller Pump Mass Concentration Instrument to be Calibrated Mass Flow Controller Pump Dump flow Mass Flow Controller 35 Pump

36 Example TOT EC Calibration 36

37 Engine Mass Data vs Average of 8 Mass Instruments (Max-Min)/((Max+Min)/2) = 26.0% 37

38 A-PRIDE 5 Engine Number Data 38

39 Summary from A-PRIDE 5 Experiments Overall, documented approach is working well multiple systems and instruments in reasonable agreement general satisfaction with number measurements knew in advance there would be some uncertainties largest differences may be due to system losses concerns about mass measurements appears to be bias between instrument types differences coincide with introduction of TOT EC calibrations VARIAnT conducted to assess bias and reduce uncertainty MSS is consistent with TOT EC on engine, LII shows bias MANTRA conducted to investigate particle properties causing bias between calibration and engine measurements 39

40 MANTRA Engine and minicast Investigate differences in response of mass instruments over ranges of size, EC/OC ratio, and mass concentration that would be anticipated in aviation engine emissions measurement perform nvpm emissions from Gnome engine at Rolls-Royce companion measurements using minicast soot generator compare the mass reported by LII and MSS while independently varying: concentration size of particles OC/EC ratio - no impact trend observed - no impact trend observed - no impact trend observed additional work with CPMA to investigate particle phase Raman analysis to investigate internal structure 40

41 MANTRA Engine and Instrumentation 41

42 microraman surface analysis of engine nvpm and soot Identifies internal structural features in carbon particles bonding (sp2 vs. sp3) degree of graphitization G graphitic D1-D4 disordered/ amorphous 42

43 Review - features in Raman spectra engine nvpm vs. lab flame soot 650 M 1-SPA750-DP1_AVE E DP1a_AVE J2_E _DP2_AVE G DP1_AVE SP-A1_ave SP-A_ave Intensity engine nvpm lab flame soot distinctive shoulder from lab flame soot (a.u.)

44 Raman spectroscopy 44

45 Raman spectroscopy 45

46 MANTRA Summary and Next Steps Distinctive difference noted between previous lab flame soot and aviation engine nvpm Raman spectra need to validate by calibrating instruments with new minicast setpoint and then perform engine measurements, with EC/OC filters for comparison perform research to support definition of tighter parameter specification for calibration lab flame aerosol source adopt tighter specification into next version of Annex 16 (CAEP/ 11) investigate improvement of calibration method for mass instruments with CPMA on new minicast setpoint ongoing separately funded project to provide equivalent calibration method in next version of Annex 16 or ETM (CAEP/ 11) 46

47 Summary and Overall Status Newly revised ANNEX 16 Appendix 7 to the Chicago Convention is being reviewed by ICAO/CAEP anticipated to be accepted and forwarded to member states for adoption in national regulations not perfect, but sufficient for the new certification requirement Mass current calibration procedure is TOT EC filter method? MSS is considered accepted; LII needs to demonstrate lack of bias on engine nvpm with new calibration source Number tremendous losses in sampling system (factors of 2x to 10x) line loss correction method developed 47

48 Summary and Overall Status SAE ARP to be balloted in Q engine types being tested represent most of in-service fleet Anticipate future removal of smoke number requirement Initial standard will pass all current engines Date from 25 engine types will inform future reductions on mass and number Ultimately, aviation is intended to have less impact on air quality and climate Similar approach is being considered for shipping by IMO 48

49 Thank you Dr. Gregory J. Smallwood Program Leader, Metrology for Industry and Society phone: web: