1. Feasibility report on the extension of the RDE procedure to particle number Progress update
Francesco Riccobono, Barouch Giechaskiel, Pierre Bonnel
Institute for Energy and Transport
Joint Research Centre
03 February 2014

2. Outline Introduction Comparison of PMP systems
Comparison of PEMS-PN systems vs PMP
On-road tests
Extreme conditions
Moped (Oil particles)
Regeneration
Calibration issues
Conclusions

3. Scope and methods
Aim of the feasibility study: Assess and validate the application and performance of portable PN instrumentation relative to each other and to a standard instrument.
Evaluation criteria:
-Linearity of the portable system with the reference system on-dyno
-Stability and performance of long sampling on-road

4. Experimental setup 5 candidate PEMS-PN instruments
5 vehicles (3 GDI, 1 MPI and 1 Diesel w/DPF)
5 cycles (NEDC, WLTP, RDE, ARTEMIS, Steady State) at 8 and 23 C
94 tests on-dyno, 283 sub-cycles
Comparison of PEMS-PN (all in parallel) with CVS reference, calibration
8 tests on-road (GDI vehicle)
4 PEMS-PN candidates (1 at a time) +
1 Reference candidate instrument always on board gas PEMS Two types of tests: 1 and 2 hour long

5. Comparison of PMP systems
CVS vs Tailpipe: Good correlation until CVS detection limit

6. Detection limit PMP

7. PMP systems
Differences +/-25%
MPI

8. PEMS-PN vs PMP

9. PEMS-PN vs PMP

10. On-road tests
All instruments demonstrated to be stable over long sampling tests on-road (2 hours)
All instruments showed similar deviations from the reference PEMS-PN on-road and on-dyno

11. Moped tests (extreme condition 1)
Volatile artifacts with PMP + 3 nm CPC
Cut-off size important
CPC
CPC
PEMS PN with VPR

12. Regeneration (extreme condition 2)
Volatile artifacts with PEMS-PN without VPR
VPR important
PN (cm-3)
PN (cm-3)

13. Detailed analysis of extreme cases
Ideally the system should have both VPR and 23 nm cut-off
Minimum temperature of 200°C can be accepted with enough residence time (info from manufacturers needed) or other technologies (e.g. catalytic stripper)
Cut-off size requirement will apply

14. Calibration and sensitivity analysis
Preliminary results show the sensitivity to bigger particles (impactor or cyclone might be required)

15. Calibration and sensitivity analysis
Sensitivity analysis to be conducted
Calibration procedures to be defined
Volatile removal efficiency tests to be done

16. Specific conclusions 1/2
PMP systems (CVS vs tailpipe) within ± 25%
On-road tests showed consistent results with lab tests (i.e. similar deviation from the reference PEMS-PN)
Good stability over long sampling on-road
PEMS-PN vs PMP: Accuracy within a factor 1.4-2
Low ambient temperature tests indicated sometimes big deviation from PMP

17. Specific conclusions 2/2
The diffusion charging principle was shown to be an acceptable technique alternative to CPC
Extreme conditions (moped, regeneration) confirmed the need of proper thermal pre-treatment and suitable cut-off size
Temperature ≥200°C
Residence time requirement and/or other techniques
Cut-off around 23 nm
Lab calibration identified the need of larger sizes cut-off
To be discussed cut-off above 500nm

18. Summary PEMS-PN 1 PEMS-PN 2 PEMS-PN 3 PEMS-PN 4 PEMS-PN 5
Pass vs PMP 23°C (<6e11 km-1)
Fail vs PMP 23°C (>6e11 km-1)
Pass vs PMP 8°C (<6e11 km-1)
Fail vs PMP 8°C (>6e11 km-1)
Regeneration
On-road
PEMS-PN 1
PEMS-PN 2
PEMS-PN 3
PEMS-PN 4
PEMS-PN 5

19. Thanks for your attention!