low nox flameless combustion for jet engines and gas turbines · engine laboratory technion ......

Turbo and Jet

Engine Laboratory

Technion – Israel

9th Israeli Symposium on Jet

Engines and Gas Turbines,

October 7 2010,

Technion, Istarel

www. jet-engine-lab.technion.ac.il1

"Low NOx Flameless Combustion

for Jet Engines and Gas turbines"Yeshayahou Levy

Technion - ISRAEL

http://jet-engine-lab.technion.ac.il

9th Israeli Symposium on Jet Engines and Gas Turbines

October 7 2010, Technion, Istarel

•Dr. Valery Sherbaum, Technion

•Dr. Vitali Ovcherenko, Technion

•Dr. Vladimir Erenburg, Technion

•Dr. Igor Geisinski, Technion

•Mr. Josef Shemenson , Technion

•Dr. Arvind Rao, Delft, The Netherlands

•Prof. Mario Costa, IST, Portugal

•Prof. Farid C. Christo, The University of South, Australia

MY THANKS TO ALL CONTRIBUTORS:

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Noise (dB)Nox, CO, UHC

(%)Fuel

Consumption

(%)

Maintanance

Cost (%)

2025

2015

present

0

10

20

30

40

50

60

70

80

90

100

2025

2015

present

NOx, CO & UHC emissions are to be reduced by 70% by year

2015 and 80% by year 2025

Fuel Consumption & CO2 emission to be cut by 15% by year 2015

and 25% by year 2025

Anticipated Future Projections of

Engine performance

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


NOx Formation in Combustor

• Conventional combustion process

– Primary zone (2500K)

– Dilution zone (TET=1600K)

• Formation (simplified) pathways:

– Thermal (>1800K)O2 <=> 2O

N2 + O <=-> NO + N

N + O2 <=> NO + O

– Prompt (CH, HCN,..)

– Fuel-nitrogen (bound N)

CONVENTIONAL COMBUSTOR

NOx FORMATION REGION

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


T

X

400° C

2200° C

1300° C

1500° C

No NOx

productionflameless

conventional

THE CONCEPT OF FLAMELESS GAS TURBINE

COMBUSTOR

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Flameless Combustion

Different Combustion Regimes (Milani & Saponaro, “Diluted

Combustion Technologies”, IFRF Combustion Journal, 2001)

CHARACTERISTICS

Recirculation of combustion products

at high temperature (> 1000°C)

Reduced oxygen concentration at the

reactance

Highly transparent flame with low

acoustic oscillation

Distributed combustion zone

Uniform temperature distribution

Reduced temperature peaks

Low adiabatic flame temperature

High concentration of CO2 & H2O

Lower Damköhler number

Low NOx and CO emission

LARGE VOLUME

% O2

% (N2+CO2+H2O)

Observed

Experimental

Temperature

Distribution

Plessing et al., 1998

REGULAR FLAMELESS

FLAMELESS OXIDATION METHOD FOR NOx REDUCTION

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


FLAMELESS COMBUSTION PRINCIPLE

Conventional Combustor

High Peak Temperature

Thin reaction zone

High Temperature

Gradients

High NOx production

Gas

Air

Low NOx Combustor

Low temperature peak

Distributed flame

Temperature

Uniformity

Low NOx production

Gas

Air

Texit

Texit

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


FLAMELESS OXIDATION IN FURNACES AND

GAS TURBINE.

Heat extraction

Main combustion(flameless oxidation)

Inlet Exhaust

0-5% O2

Industrial Furnace

Main combustion

Inlet

Exhaust

14-18% O2

Gas Turbine

FLAMELESS OXIDATION IN FURNACES

?

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


IMPLEMENTATION OF FLOXCOM METHOD

IN GAS TURBINES

CONVENTIONAL GAS TURBINE

GAS TURBINE WITH THE FLOXCOM COMBUSTOR

●5

●3

●2

●1

●6

●4

●3’

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


INDICATIONS OF INCOMPLETE COMBUSTION

CFD SIMULATIONS

(Farid C. Christo, The University of South Australia)

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Diluting air Stirring air

A 600 MODEL OF THE COMBUSTOR SHOWING

STIRRING AND DILUTING AIR INLET HOLES

OPTIONAL AIR INLETS MODIFICATIONS

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


SECTOR COMBUSTOR - FULLY

ASSSEMBELED

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


OPERATING TEST RIG AT IST, PORTUGAL

PHASE I

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


COMBUSTION TESTS

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


72

66

60

54

48

42

36

30

24

18

12

6

0

10 m/s

k (m2s

-2)

O1I

A22SHI

A23SHI

A24SHI

A21SHI

Ø4

Ø4

MEAN VELOCITY VECTORS AND TURBULENT

KINETIC ENERGY FIELDS AT THE

MEASUREMENTS AT SYMMETRY PLANE INSIDE THE COMBUSTION CHAMBER

PRIMARY ZONE

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


CONTOURS OF TEMPERATURE AND O2,

CO, NOX, HC, AND CO2 CONCENTRATIONS

MEASUREMENTS

PERFORMED AT

THE SYMMETRY

PLANE

(IST PORTUGAL)

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


HIGH PRESSURE FLOXCOM TEST RIG AT

ANSALDO BARI

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


EMISSION TEST DIAGRAM AT 2.5 BARS (abs.),

NO AND NO2 Vs. THE EXCESS AIR PARAMETER

0

2

4

6

8

10

12

14

16

18

20

2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1l

ppm

0

200

400

600

800

1000

1200

1400

1600

1800

2000

ppm

NOx

NO

CO

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


a)

b)

c)EFFECT OF GEOMETRICAL

VARIATIONS

Config.

Air inlet (total = 14 holes × 2 sections)

Left inlet Right inlet

A oooooooooooooo oooooooooooooo

B o●o●o●o●o●o●o● o●o●o●o●o●o●o●

C oooooooooooooo●●●●●●●●●●

●●●●

D o●o●o●o●o●o●o●●●●●●●●●●●

●●●●

P=1 bar (abs)

Q= 4KW

(24 KW complete section)

PRELIMINARY DESIGN MODIFICATIONS

NOx

COMBUSTION EFFICIENCY

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


EFFECT OF FUEL COMPOSITION

(COMBUSTION OF SYNGAS)

a)

b)

c)

P=1 bar (abs)

Q= 8KW

(48 KW complete section)

94321Fuel mixture

39.27681.991100CH4

43.32418.190H2

17.50000CO2

18.7029.7931.2733.5535.80LHV (MJ/Nm3)

19231965196119561952Tad (ºC)

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


• FLOXCOM COMBUSTOR HAS LARGE STABLE OPERATIONAL

RANGE.

• NOx EMISSION IS LOW AS EXPECTED.

• CO AND UHC ARE MODERATE, DESIGN MODIFICATION IS ARE

REQUIRED

• BASIC STUDY IS NEEDED TO FILL GAPS

INTERMEDIATE CONCLUSION

2nd PHASE OF THE STUDY:

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


New design for Aero-engine

Heat extraction

Main combustion

Inlet

Exhaust

5-8 % O2

MODIFIED FLAMELESS COMBUSTOR WITH

INTERNAL HEAT EXCHANGER.

ADVANTEGEOUS:

•COOLER FLAME

•NEED FOR LOWER RECIRCULATION RATIO

21 % O2

Main combustion

Inlet Exhaust

14-18% O2

Conventional Flameless for Gas Turbine

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


HEAT AND FLOW DIAGRAM -

MODIFIED FLAMELESS COMBUSTOR.

2 3

1

Heat exchanger

5

4

x Junction

Primary Air

Secondary Air

Inlet ExitRecirculation Zone

Main Combustion

Pre

-com

bu

stion

2 3

1

Heat exchanger

5

4

x Junction

Primary Air

Inlet Exit

Main Combustion

Pre

-com

bu

stion

Fuel

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


THE HEAT TARNSFER MECHANISM

אזור האוויר

העוקף

פתח הזרמת

אוויר

פתחי הזרמת

דלקצלעות מחליף

החום באזור

הבעירה

) אזור(דופן תא

הבעירה

USING OPTIMAL CONFIGURATION, COMBUSTION TEMPERATURE MAY BE

REDUCED BY AS MUCH AS 170 °C !

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel

www. jet-engine-lab.technion.ac.il24SINGLE JET STUDY

SINGLE JET FLAMELESS COMBUSTOR

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


DIFFUSION

FLAMELESS

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


CFD SIMULATIONS - TECHNION

COMBUSTION CHAMBER WITH 16 FUEL INLET

AIR INLET

CH4

Air

MESH FOR 1/16

SECTOR

GASEOUSE

FUEL INLETS

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


TEMPERATURE DISTRIBUTION

TEMPERATURE

DISTRIBUTION

~1800K

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


VELOCITY FIELD AT THE CENTER LINE

CROSS-SECTION

| | | | | | | |

0 25 50 75

mm

To outlet

CH4 inlet

Air inlet

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


To outlet

Vz - VELOCITY COMPONENT'S DISTRIBUTION

RECIRCULATION REGION

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


TEMPERATURE DISTRIBUTION –

(NEAR NOZZLE REGION)

| | | | |

| |

0 3 6 9 12 mm

DIFFUSION REGION

FUEL ENTRAINMENT

NO mass-fraction distribution

Temperature distribution

Preliminary NO predictions

NO level

5 ppm

0

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


experiment

T K

simulation

COMPARISON – CFD SIMULATIONS -

EXPERIMENT

THERE IS STILL

ROOM FOR

IMPROVEMENTS

IN THE

MODELING …

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


-10x10-601630-Exp. data

1.60.76x10-62.5x10-12 ≃ 016802190Flux = -25kW/m2

1.64.4x10-63.3x10-12 ≃ 017602290Flux = -15kW/m2

1.646x10-68.6x10-12 ≃ 019002460Adiabatic

Krecirc.NOexitCOexitTexit , KTmax , KRegime

COMPARISON OF SIMULATION AND

TEST RESULTS

INCORPORATION OF

HEAT LOSS IN THE

MODELING IMPROVED

RESULTS

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


summary

• Basic modeling of the FLOXCOM combustion method was complete.

• Detailed investigation into internal mixing and enhanced wall heat transfer is currently being performed.

• CFD modeling of Jet Flame configuration coupled with experimental result seems to present an efficient tool to gain practical knowledge.

• Final integration stage is still needed for an engineering flameless combustion design

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


INCORPORATION OF MODIFIED COMBUSTOR

IN A TURBO-FAN ENGINE.

c

c

1

9'9' n ' pc 07'

07 '

PU 2 C T 1

P

GE-90

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Pollutant Reduction Problem

• Compromises involved with

conventional combustors:

– Emitted species

– Flame stability

– Cycle efficiency

• Need for alternative

combustion concepts

LOW-EMISSION WINDOWWulff and Hourmouziadis, 1997

35

LOWER STABILITY LIMIT

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


COMBUSTION IN HOT VITIATED AIR

Stability limits -SchematicAfter Wunning and Wunning, 1997

Observed Experimental

Temperature DistributionPlessing et al., 1998

Flame

• Stable and safe

combustion

• Uniformly

distributed

temperature

• Low-NOx emission

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


O2, CO2, H2O MOLE FRACTION AT THE

RECIRCULATION ZONE

0

2

4

68

10

12

14

16

0 5 10 15 20 25

Oxygen mole fraction, %

Industrial

furnaces

Gasturbines

II I

I – BEFORE COMBUSTION

(STIRRING AIR),

II – AFTER COMBUSTION,

CO2 ,

H2O.

IF GASES WITH LARGE OXYGEN CONCENTRATION ARE RECIRCULATED, HIGH ADIABATIC TEMPERATURES ( AND NOx) ARE OBTAINED

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Recirculation Zone

InletExit

Recirculation Zone

Primary

air

Mixing Zone

SCHEMATIC REPRESENTATION OF THE FLUID

FLOW WITHIN THE “MODIFIED” COMBUSTORS

Fuel Inlet

Fuel

Inlet

Exi

t

Composite

Metallic Fins

Secondary Air

Mixing holes

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


Known parameters and assumptions:

•Inlet air temperature Ta

•Inlet mass flow rate ma ,

•exit temperatures Te

•100% combustion and mixing efficiency

calculated Values:

•Air flow distribution: stirring air, mas,

dilution air, mad

stirring gas, mas+mr

•Temperature : stirring gas, Ts

combustion, Tc

•Recirculation rate: k•oxygen percentage in every stage of the cycle.

GLOBAL EVALUATION OF THE FLOXCOM COMBUSTOR

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


HIGH PRESSURE FLOXCOM TEST RIG

AT ANSALDO BARI

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


CROSS SECTION OF THE 360 DEGREES

MODEL OF THE FLOXCOM COMBUSTOR.

T1[ x3]

T2[ x3] [ x3]

T3

P1[ x3]

P1 - Pressure sensores

T1...T3 - Temperature Sensores

Air In Exhaust gases

Turbo and Jet

Engine Laboratory

Technion – Israel



October 7 2010,

Technion, Istarel


FLOXCOM RELATIVE

PERFORMANCE

ppm NOx

..........200 …

100..............

0 ................

low nox flameless combustion for jet engines and gas turbines · engine laboratory technion ......

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