Integrated Lean Low Emission Combustor Design Methodology · SARS Task 3.3.1 LPX 1 LPX 2 LN 2B LPX...

Ralf von der Bank, Integrated Lean Low Emission Combustor Design Methodology, Sixth European Aeronautics Days, Madrid, Spain, 30/3 – 1/4 2011 - 1C1

Integrated Lean Low Emission

Combustor Design MethodologyPresenter: Ralf von der Bank (Rolls-Royce Deutschland)


•

•

•

•

•

••

••

•

•

•

•

•

Rolls-Royce

Derby

Rolls-Royce

Derby

Department Chemical Engineering

Cambridge

Department Chemical Engineering

Cambridge

Imperial College

London

Imperial College

London

Combustion Physics

Universitet Lunds

Combustion Physics

Universitet Lunds

AVIO

Napoli

AVIO

Napoli

Università di

Firenze

Università di

Firenze

University of

Czestochowa

University of

Czestochowa

Rolls-Royce Deutschland

Dahlewitz / Berlin

Rolls-Royce Deutschland

Dahlewitz / Berlin

DLR

Köln

DLR

Köln

ONERA

Palaiseau

ONERA

Palaiseau

SNECMA

Villaroche

SNECMA

Villaroche

University of

Loughborough

University of

Loughborough

•

CERFACS

Toulouse

CERFACS

Toulouse

•

CNRS-LCDPoitiers

CNRS-LCDPoitiers

Universität Bundeswehr

München

Universität Bundeswehr

München

Engler-Bunte Institut

Universität Karlsruhe

Engler-Bunte Institut

Universität Karlsruhe

Turbomeca

Pau

Turbomeca

Pau

Consortium


Total Budget: 7,7 M€

EC Funding: 5,0 M€

Ratio: 64,6 %

Duration: 5 years1 January 2004 - 31 December 2007

Completed on 31 December 2008

One task delayed to 31 December 2009Status YE 2009

Budget funding spent

7.64 M€ / 4.88 M€

97 %

785 Person Months

66 Person Years

97 %

Budget and Efforts

� 93 deliverables + 47 milestones + 38 paper & conference publications

� first prolongation used to invoke BOSS / HBK1 facility (larger Aeff)

� assumption was low risk, then cracks in the silencer found

� after safety concern the silencer’s concrete structure was renovated


Strengthening of competitiveness of European aero-engine manufacturers

- reduce short & long term development costs by 20 and 50%, respectively

- incorporate new technology faster into future products

- project timescales to less than 2 years

Improving the environmental impact with regards to emissions

EC Target:

- reducing of NOx emissions by 80% in the LTO cycle relative to CAEP/2

- achieving an NOx emission index of 5 g NOx per / kg fuel burnt

ACARE “A Vision for 2020”:

- reduction of 50% CO2 emissions (engine contribution 15 - 20%)

- reducing NOx emissions by 80% with 60% combustion system contribution

Strengthening of competitiveness of European aero-engine manufacturers

- reduce short & long term development costs by 20 and 50%, respectively

- incorporate new technology faster into future products

- project timescales to less than 2 years

Improving the environmental impact with regards to emissions

EC Target:

- reducing of NOx emissions by 80% in the LTO cycle relative to CAEP/2

- achieving an NOx emission index of 5 g NOx per / kg fuel burnt

ACARE “A Vision for 2020”:

- reduction of 50% CO2 emissions (engine contribution 15 - 20%)

- reducing NOx emissions by 80% with 60% combustion system contribution

Global Project Targets


Challenges

LP(P) / LDI

50 to 80 % W30

Emissions

NOx

SOOT

CO

UHC

Cooling:

Life Prediction / Technology

Surface to Volume Ratio

Shape of the cooling holes

Pre-Diffuser:

Pressure Loss

Air Feeding

SFC

Design:

Weight

Length

Part Count

Complexity

Combustion Noise:

Thermo-Acoustic Instabilities

Combustion Driven Pressure Oscillations

Mechanical Integrity

Operability:

Combustion Efficiency

Cold Start, Ignition

Altitude Relight

Hail & Rain

Slam Deceleration

Weak Extinction

Fuel System:

Fuel Coking

Schedule

Staging Control

Fuel Types

Aromatics

Sprays:

Spray Break-Up

Spray Vaporisation

Droplet Diameters

Injectors:

Air Blast / Multi-Point

LPP LP(P) LDI

Combustor-Turbine Interaction:

Degree of swirl at the back end of the combustor

HPT NGV cooling and HPT efficiency


• Improvement of ultra-low NOx combustion systems

- lean flame stability / weak extinction, flash-back & auto-ignition

- low power conditions & transient engines operation

• Lean burn combustion

- lower combustion temperature

- reduced flame stability

- may lead at very weak conditions

- to severe increase of CO emissions and

- unburnt hydro carbon emissions right before flame-out

Deterioration when

- slam deceleration during maneuvering in inclement weather conditions

which leads to hail or rain (tropical storm) ingestion

- with further reduced compressor outlet temperature and

- reduced chemical reaction rates (moisture is almost inert)

• Improvement of ultra-low NOx combustion systems

- lean flame stability / weak extinction, flash-back & auto-ignition

- low power conditions & transient engines operation

• Lean burn combustion

- lower combustion temperature

- reduced flame stability

- may lead at very weak conditions

- to severe increase of CO emissions and

- unburnt hydro carbon emissions right before flame-out

Deterioration when

- slam deceleration during maneuvering in inclement weather conditions

which leads to hail or rain (tropical storm) ingestion

- with further reduced compressor outlet temperature and

- reduced chemical reaction rates (moisture is almost inert)

Technology Key Objectives


Technology Trades

SFC - CO2 ⇔ NOx

Source: M. Plohr, R.v.d.Bank, T.Schilling, DGLR-2003-100, Munich, Germany

Note: Fan and nacelle drag and weight variations were not considered.

� Higher P30/T30 and higher BPR improve thermal cycle and propulsive efficiency

� Reduction of fuel burn (SFC) and green house gas emissions (CO2), but:

� Aggravated situation with respect to low NOx target / challenge

Key Influencing Physical Factors

P30/T30 ⇑ SFC ⇓ CO2 ⇓

BPR ⇑ SFC ⇓ CO2 ⇓

BPR ⇑ Nacelle & Fan Drag ⇑

P30 ⇑ NOx ⇑

T30 ⇑ T40 ⇑ NOx ⇑

BPR ⇑ AFR ⇓ T40 ⇑ NOx ⇑


WP3

LUND

WP2 - TM

WP7

AVIO

LOPOCOTEP

WP3WP3WP3WP3

Ignition CapabilityIgnition CapabilityIgnition CapabilityIgnition CapabilityLunds Universitet

WP4

RRDWP4WP4WP4WP4

Stability & ExtinctionStability & ExtinctionStability & ExtinctionStability & ExtinctionRolls-Royce Deutschland

WP6

WP6WP6WP6WP6

External AerodynamicsExternal AerodynamicsExternal AerodynamicsExternal AerodynamicsLoughborough University

WP2 WP2 WP2 WP2

Knowledge Based Low Knowledge Based Low Knowledge Based Low Knowledge Based Low NoxNoxNoxNox CombustorCombustorCombustorCombustorTurbomeca

WP7WP7WP7WP7

Combustor Cooling Combustor Cooling Combustor Cooling Combustor Cooling AVIO

Air Distribution

Combustion

LOPOCOTEPLow NOx III WP6WP6WP6WP6

Technology AssessmentTechnology AssessmentTechnology AssessmentTechnology AssessmentRolls-Royce United Kingdom

Project Structure


Knowledge Based Low NOx Combustor

Parametric combustor model (Z-Ring)

Casing

CowlMetering Panel

Heat Shield

Z ring Cooling

• Light or heavy KBE systems, which include all the combustor design rules.

• Light or heavy depending on the balance between fast implementation and

adaptability to new system designs. Advanced optimisation techniques.

• In an industrial environment, a big effort is required to capture knowledge.

Deformed mesh


External Aerodynamics

• Lean Burn architecture: new challenge to External Aerodynamics design

• Optimise for minimum pressure loss and flow quality, optimised air distribution and OGV

• Developed software allows exploitation of 3D Pre-Diffuser exit height (with struts)

• LES of OGV/diffuser to develop constraint for 3D RANS • more LES in the future

15%

15%

up to 70%

35%

35%

up to

30%


Combustor Cooling

• Understanding of air flow through effusion cooling holes improved and characterised

• Discharge coefficients for circular (cd = 0.7) and shaped cooling holes determined (0.85)

• Effusion cooling air flow simulated by LES and RANS CFD / very high spatial resolution

• Combustor wall temperatures predicted (convection and radiation / conjugate heat transfer)

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Re2 = 11000

Re2 = 11000

Re2 = 22000

Re2 = 28000

Re2 = 33000

Re2 = 39000

manip h_ad

Re hole

Cd

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 4000 8000 12000 16000 20000

Re1 = 78000 – Re2 = 17000

Re1 = 78000 – Re2 = 33000

Re1 = 79000 – Re2 = 51000

Re1 = 79000 – Re2 = 70000

Re1 = 79000 – Re2 = 87000

Re1 = 78000 – Re2 = 106000

Re h

C d


Ignition Capability

• High altitude relight (1-sector, 2 sector & sub-atm. FANN) capability > 30,000 ft demonstrated

• Fundamental spray break-up models implemented and validated

• Ignition, light-up, light across simulated in 3-sector CFD domain capability demonstrated

• Ignition process investigated with high-speed framing camera (spark plug & laser)

00:00:0000:00:00 00:05:4300:05:43 00:05:4400:05:44

00:05:4900:05:49 00:05:5200:05:52 00:05:5400:05:54

00:05:5600:05:56 00:05:5800:05:58 00:06:0100:06:01

Spark plug & laser pulse ignition


Stability & Extinction

SARS

Task 3.3.1

LPX1

LPX2

LN2B

LPX1

HBK3

EDS-SSC / BOSS

Task 4.2

LP(P)5

LPX2 LN2B

Task 4.1

Task 5.1/ 5.2

LN2B

NEW BOSS

S-FANN

Task 3.3.2

LPX1.MOD

700 m2

M1-HPSS Task 4.3

B61PERM

SARS

Task 4.4

LN2B

LES-BOFFIN

Task 4.5 / Task 3.1

LPX1

DESS

Task 3.2

LP(P)4-P1

LPX1.MOD

ICL


Synthetic Paraffinic Kerosine (one example GTL-SPK)

• First time ever investigation of one GTL

• Generally less soot (no aromatics)

• NOx emissions increased (pilot PSA)

• Ignition delay time (distillation curve)

• Need for further research identified

• Results were not well understood

• LIF / Mie scattering (kerosene) • OH* chemiluminescence (heat release)

•G

TL-S

PK

•

pet. J

et-

A1

• doubling of ignition delay time to 12 sec. • reduced soot deposit


Assessment 1 – Combustor Architectures

E3E I – ASC – air blast

NOx 47% CAEP/2

BR715 – RQL air blast burner optimised RQL potential

NOx 60% CAEP/2 up to: NOx < 50% CAEP/2

E3E II / ASC / SC1

NOx < 43% CAEP/2

FP4 LowNOx III / ASC / LPP1 / LPP2

NOx < 57% CAEP/2FP5 LOPOCOTEP / LP(P)5

NOx < 40% CAEP/2 AM

FP6 INTELLECT D.M.

NOx < 26% CAEP/2 AM (LN2B)

NOx = 6.6 g/kg (AM cruise)

LOPOCOTEP - LARGE A (CLEAN)

NOx < 60% CAEP/2


Assessment 2 – Continued Progress

• Medium size turbofan engines

• State of the art: Single Annular Combustors with rich burn (air blast) injection

• LowNOx III (1998-2001) - proof of concept

Double Annular Combustors / Axially Staged Combustors (rich/rich)

First experience with lean burn injectors (mainly: LPP)

• LOPOCOTEP (2001-2006) - proof of concept

Double Annular Combustors / Axially Staged Combustors (rich/lean)

First experience with piloted lean burn injectors (mainly: LP(P), LDI, Multi-Point)

• INTELLECT D.M. (2004-2009) - proof of concept

Single Annular Combustors with piloted lean burn injectors (mainly: LDI, PERM)

Best results: 25.9 % CAEP/2 AM vs. 20% CAEP/2 (target EC FP6 work programme)

Best results: 6.6 EINOx,c @ cruise vs. 5.0 EINOx,c (target EC FP6 work programme)

First experience with operability (cruise operation, weak extinction, altitude relight,

ignition (light-up,light-across, light-around), etc)

On-going: Transition to higher TRL (NASA AST: NOx deterioration factor up to: ~1.5)

Further optimisation and concept development


Assessment 3 – emission performance of LDI modules

Result of assessment of NOx performance on the ICAO LTO cycle

(advanced medium size turbo-fan engine @ 129 kN - 100% T/O thrust, SLS)

Injector type CAEP/2 limit [AM] CAEP/2 limit [C1] TRL

LP(P)5 34.0% - 40.5% 39.3% - 46.9% (mlc - wc) 3

LPX1 33.3% 38.6% 3

LPX2 32.9% 38.2% 3

LN2B C22 25.5% 29.5% 3

RQL (optimised) 62.8% 72.8% (from CYPRESS) 9

• The LN2B fuel injector is almost achieving the EC target set (20% CAEP/2)


Conclusions

● all partners completed their technical/research work successfully

● first building bricks for light and heavy KBE systems were developed

● ignition capability (simulation and testing) was extended to lean burn systems

● advanced LDI systems were developed and tested for emissions and operability

● first time ever: Fischer-Tropsch GTL was investigated with advanced LDI module

● assessment showed that 80% NOx (CAEP/2) reduction can be achieved with

LDI lean burn systems (medium size engines with 20 bar < P30 < 40 bar were targeted)

further potential by UH-BPR and UH-OPR / further research required (CO2 and NOx)

● external combustor aerodynamics were optimised for 70% air flow though LDI module

● cooling technologies were driven to higher efficiency and higher cooling requirements


Many thanks to the team!

Ralf von der Bank, Integrated Lean Low Emission Combustor Design Methodology, Sixth European Aeronautics Days, Madrid, Spain, 30 March - 1 April 2011

Group photo of the INTELLECT D.M. team at the Final Review

Integrated Lean Low Emission Combustor Design Methodology · SARS Task 3.3.1 LPX 1 LPX 2 LN 2B LPX...

Documents

Transcript of Integrated Lean Low Emission Combustor Design Methodology · SARS Task 3.3.1 LPX 1 LPX 2 LN 2B LPX...