ESTABLISHMENT OF THE PEMS-PM INSTRUMENTATION SPECIFICATIONS FOR THE IN-SERVICE-CONFORMITY OF HDE IN EUROPE

Transcription

1 ESTABLISHMENT OF THE PEMS-PM INSTRUMENTATION SPECIFICATIONS FOR THE IN-SERVICE-CONFORMITY OF HDE IN EUROPE Athanasios Mamakos*, Pierre Bonnel, Massimo Carriero, Adolfo Perujo Institute for Energy and Transport Joint Research Centre *Southwest Research Institute

2 EU PEMS-PM program overview Aspects of research: Instrumentation intercomparison / equivalence Influence of particulate matter physical properties - Mass - Number and size of particles - Chemical composition Upon the measurements - Total mass collected on different medias - Real-time detectors Sampling duration Project Phase 1 (3 engines) Phase 2 (DPF + bypass) Phase 3 (DPF + bypass) Phase 4 Validation (DPF + bypass)

3 Candidate PEMS-PM instrumentation Candidate Dilution PM mass Real time sensor AVL Control Sistem Fixed (3:1 12:1) Proportional (30 lpm) Gravimetric Gravimetric Photoacoustic Diffusion Charger New element Dekati No * Mobility & eff. density Horiba Sensors Proportional (30 lpm) Proportional Gravimetric Quartz Crystal Microbalance Electrical Impactors Diffusion Charger No Existing element in regulation * A needle-type dilutor could not be assessed on-time

4 Reference Instrumentation Constant Volume Sampler tunnel: Gravimetric PM mass AVL-SPC 472 Proportional Partial Flow Dilution System (PPFDS): Gravimetric PM mass Horiba Solid Particle Counting System (SPCS): Regulated Particle Number (PN) emissions

5 Experimental Engines Phase 2: IVECO Cursor 8 - Euro III, 7.8 dm 3, 6 cylinders rpm rpm Phase 3 & 4: IVECO Cursor 10 - Euro III, 10.3 dm 3, 6 cylinders rpm rpm

6 Experimental Aftertreatment Bypass to simulate different PM levels Phase 2: CRT dm 3 Pt-based Oxidation Catalyst - 24 dm 3 Johnson Matthey DPF Phase 3: DPF - Uncatalyzed Pirelli FeelPure DPF Phase 4: CRT - Oxidation Catalyst & Catalyzed DPF (Baumot)

7 Experimental Test Cycles Focus on World Harmonized Transient Cycle (WHTC) - Single and repeated WHTC over a single filter - Focus on hot-start Selected steady states - ESC mode 7 (Speed A 25% load) - ESC mode 12 (Speed C 75% load) Passive regeneration investigations

8 PM results Limit of Detection Background tests allowed for the estimation of the Limit Of Detection (LOD). Filter media type effect was not consistent. Increase of sampling time to 120 min, significantly improved the LOD, bringing it below 3 mg/kwh.

9 PM results assessment 1xWHTC Laboratory-grade Partial Flow Dilution System (PFDS) served as a reference. Minimal errors of omission and commission are of most importance Conformity factor (assumed 1.5) relaxes the criteria

10 PM results single WHTC 1xWHTC PEMS-PM candidates exhibited similar performance to the reference PFDS in terms of discriminating PM levels above and below EURO VI. AVL performance with TX40, improved with the use of a spacer (increasing filter face velocity from 5 to 45 cm/s).

11 PM results 3xWHTC Evidence that the discrimination capabilities of all systems is improved by extending the sampling time. 3xWHTC

12 PM sensor results Sensitivity All sensors have the potential to discriminate emission levels down to the PN limit of #/kwh or even lower Importance to avoid volatile particle interference!

13 Similar artifacts also for the Pegasor sensor, where internal modifications are envisaged. Performance still needs to be verified. PM sensor results Volatile interference Volatile particle nucleation led to a several orders of magnitude increase of the HORIBA EAD response. Use of diffusion screens at the inlet of the EAD was proven an efficient means to avoid such artifacts.

14 Conclusions PM-mass Prolonged sampling times, envisaged in the EU PEMS- PM approach, are essential for a) accurate quantification of gravimetric PM emissions and b) minimal contribution from background. To avoid excessive adsorption artifacts, a minimum filter phase velocity (provisionally set at 45 cm/s) will be required. - Constant dilution systems will only be considered as alternatives, and only if the real time sensor provides quantitative information on PM mass. All three PEMS-PM candidates exhibited similar performance with the reference PFDS system in terms of discriminating PM emissions above the EURO VI levels.

15 Conclusions PM Sensors All particle sensors exhibited impressive sensitivity, being capable of quantifying emission levels below the particle number limit of #/kwh. Nucleated particles can lead to a disproportional increase of the diffusion charger responses (like PPS and EAD). Interference from nucleation mode particles need to be avoided by either internal (e.g. trap voltage) or external (e.g. diffusion screens) means. - Provisional penetration requirements of 10% at 30 nm and 50% at 70 nm.

16 Thank you for your attention! More info at: Journal of Aerosol Science, 57:54-70 Acknowledgments: MM. Les Hill, Daniel Scheder (HORIBA) M. Cesare Bassoli, Daniele Testa (CONTROL SISTEM) MM. Oliver Franken, David Booker (SENSORS EUROPE, SENSORS INC) MM. Karl Obergugenberger, Wolfgang Schindler (AVL) MM. Ville Niemela, Erkki Lamminen (DEKATI)

17 Application of MAW: at 20% bypass At ~8mg/kWh levels, the normalized sensor responses differed by a maximum ±10%. Again the uncertainty in the quantification of PM emissions (±40%) dominates.

18 PM results Passive regeneration Volatile release during passive DPF regeneration can lead to large increase of collected PM mass