nvpm Measurements at Rolls-Royce

Transcription

1 nvpm Measurements at Rolls-Royce FORUM-AE non-co2 Emissions Workshop Denise Ahrens, Paul Madden, Mark Johnson Berlin, 8 th -9 th March 2017 Rolls-Royce Deutschland Ltd & Co KG The information in this document is the property of Rolls-Royce Deutschland Ltd & Co KG and may not be copied or communicated to a third party, or used for any purpose other than that for which it is supplied, without the express written consent of Rolls-Royce Deutschland Ltd & Co KG. This information is given in good faith based upon the latest information available to Rolls-Royce Deutschland Ltd & Co KG, no warranty or representation is given concerning such information, which must not be taken as establishing any contractual or other commitment binding upon Rolls-Royce Deutschland Ltd & Co KG or any of its subsidiary or associated companies. Trusted to deliver excellence

2 Acknowledgement The support of the following parties is kindly acknowledged.

3 Introduction Non-volatile Particulate Matter (nvpm) is measured with standardised measurement system 3 Appendix 7 of ICAO Annex 16, Vol. II defines all procedures, calibration, measurement instruments and sampling system Measurement characterises nvpm mass and number Certification requirement with CAEP/10 (executive Jan 1 st 2020) nvpm system loss factors calculated to AIR6504 RR supports ICAO CAEP work on developing a new particle standard Commitment by all engine manufacturers to measure engines in production (collected in nvpm database) RR provides additional measurements and analysis helping to develop corrections for engine-to-engine variability, ambient conditions, and to validate system losses Some engines were measured back-to-back with the EASA reference system and use of quartz filters for mass validation

4 RR nvpm Sampling and Measurement System 4 Appendix 7 compliant nvpm measurement system Including: Leak and volatile particle remover dilution checks nvpm engine inlet ambient data System particle loss calculation: Appendix 7 - Data corrected for particle size independent thermophoretic loss (Engine exhaust to sampling line temperature) AIR Particle size dependent system loss factors are calculated for number and mass measurements mainly due to diffusion loss mechanism

5 nvpm Measurement Equipment 5 RR Measurement System (Appendix 7 compliant) Optional RR nvpm Measurement System EU/EASA nvpm Reference System (& Cardiff Uni particle size)

6 Ambient Conditions Example RRD Engine 6 Ambient Environment Temperature (K) Pressure (kpa) Specific humidity (kg/kg) First day Second day Ambient nvpm Average nvpm number concentration (#/cm 3 ) Average nvpm mass concentration (µg/m 3 ) First day 2.28E Second day 3.20E

7 Fuel Content Analysis 7 Fuel samples taken for each curve (before and after test) Full analysis for ICAO specification Property Allowable Range Curve 1 Curve 2 Curve 3 Specific Density, kg/m 3 (15 C) Distillation temperature, C - 10% boiling point final boiling point Net heat of combustion, MJ/kg Aromatics, volume % Naphthalenes, volume % Smoke point, mm Hydrogen, mass % Sulphur, mass % < <0.001 Kinematic viscosity, mm 2 /s (-20 C)

8 Particle Emissions vs Aromatic Fuel Content 8 Brem et al, FORUM-AE WS Amsterdam Variation of aromatic content within ICAO fuel spec Aromatics content has a higher effect on particle emissions at low power

9 nvpm Initiation, Production, and Consumption nvpm Formation Initiation: local condition in PZ, fuel content Production and Consumption: (residence time on) condition along streamline Trade-off: NOx vs. nvpm/smoke (residence time in hot environment) 9 T30 nvpm P30 nvpm AFR nvpm AFR nvpm AFR distribution in a RQL combustor

10 RR Engines nvpm Results 10 Full dataset consists of Raw measured data of nvpm number and mass concentrations Dilution and thermophoretic corrected nvpm mass and number concentrations Calculated Emission Indices of nvpm mass and number (corrected for thermophoretic loss) Calculation of mass and number system loss factors Additional information Particle size distribution (measured values by Cardiff vs. modelled GMD by system loss tool) Measurement system comparison (RR vs. EASA)

11 EI Mass and Number over T30 11 Same level Example for one engine type (MTF Mixed Turbo Fan) Two production engines Similar ambient conditions Reasonable engine-to-engine variability nvpm number increases at low power

12 EI Mass and Number over T30 12 Variability Example for one engine type (large engine) Two production engines on different occasions Different ambient conditions Wider scatter for number nvpm number increases at low power

13 Particle Size Distribution Example for one engine type (y-axis normalised) Thrust

14 14 Particle Size (Geometric Mean Diameter GMD) Measured vs Engine Exit example for one engine type Consistency between curves/multiple engines (single type) Largest particles at high power, smaller particles towards low power Particle Sizes are in the typical range for aero-engines The difference between modelled engine exit and measured particle size is due to sampling system loss and is larger when particle sizes are smaller

15 Engine Exit Particle Size Comparisons 15 Particle size variation observed between different engine types 10-50nm 20-60nm Small Engines were measured in mixed turbofan configuration

16 Measurement System Comparison TF 16 Measured values of LIIs and MSS show good accordance Similar scatter for RR and EASA system MSS and LII equally suitable for measuring particle mass

17 Measurement System Comparison MTF 17 Comparison of LII to MSS Higher Scatter with mixed flow sampling as absolute measured values are small and close to Limit of Detection

18 System Loss Calculation 18 Reporting of System Loss Factors to nvpmdb Number system loss factors much larger than for Mass due to larger particles being preferentially transported through the system Differences in Number system loss factors due to particle loss differences between manufacturer VPRs

19 EIn (EASA) EIn (EASA) VPR Loss Comparison 19 Additional (compared to mass) particle loss for number measurement occurs in VPR There is higher measured (for calibration) particle loss in EASA VPR type system. Correcting for this loss appears to be an overestimation and maybe calibration particle material dependent No System Loss Correction System Loss Correction with different calibration particle material types EIn (RR) EIn (RR)

20 Summary 20 RR support ICAO CAEP work on developing a new particle mass and number standard RR has a fully compliant nvpm measurement system, in addition back-to-back measurements with the EASA Reference System were taken and are available for further analysis RR has conducted more than 10 nvpm measurements on more than 5 different engine types; most inputs of relevant engines into CAEP WG3 nvpm database are done Corrections for ambient condition (resulting in different AFR, P30 at a given T30), fuel content, and particle system loss must be studied in more detail