development of criteria for flameholding tendencies within premixer passages … · 2013-08-22 ·...

1

Development of Criteria for Flameholding

Tendencies within Premixer Passages for High

Hydrogen Content Fuels

Elliot Sullivan-Lewis, Richard Hack, and Vincent

McDonell

UTSR Workshop

Oct 4, 2012

Contract DE-FE0007045; Joe Stoffa, Contract Monitor

Outline

• Motivation

• Background

• Research Questions and Project Goal

• Approach and Schedule

• Test Rig Development

• Current Status

UTSR Workshop, Irvine, CA Oct 2012 2/44

2

Motivation

• Trends in Advanced Lean Burning Gas Turbines*

– Higher Combustor Inlet Temperatures

– Improved Fuel/Air Mixing

– Risk of Auto-Ignition/Flashback

– Role of Fuel Type/Composition

Major Question

If a Reaction is Initiated in the Premixer,

Will the Reaction be “Held” on a Wall Recess?

* Stationary Gas Turbine Engines

Air

Fuel

Reaction

L

pre-mixer lengthcombustor

P: 1-35 atm.

T: 500-1000K


Motivation

Pressure spike

at ignition

Pressure drop

surge after

ignition

• Ignition/reignition of all fuels (natural gas

and hydrogen) leads to a pressure spike

that can allows flame to propagate up

into premixer

• Natural Gas reaction disgorges

• Hydrogen reaction anchors in premixer

zone


3

Motivation

Desired:

Tools to guide premixer

design for robustness

relative to flame attachment

and disgorgement

High Hydrogen

Content

Fuels

On

N.G.

injectors


Background

• Large Body of Literature on Blowoff/Flameholding

• Findings

– Only ~25% Focus on Natural Gas, <10% Hydrogen

– Most Focus on Centerbody Stabilization vs. Wall Effects

– Most Seek How to Stabilize, Not How to Avoid

• Studies of Particular Relevance

– Cambel, et al. (1957, 1962)

• Wall Perturbations

• Limited Conditions

• Propane

• No Variation in Temperature

• No Variation in Pressure

• No Geometry Effect Noted

• No Fuel Effects

• No Vitiation Effects


4

Background

Large Body of Literature on Blowoff/Flameholding

• Findings

– Only ~25% Focus on Natural Gas, <10% Hydrogen

– Most Focus on Centerbody Stabilization vs. Wall Effects

– Most Seek How to Stabilize, Not How to Avoid

• Studies of Particular Relevance

– Cambel, et al. (1957, 1962)

• Wall Perturbations

• Limited Conditions

– Cambel suggested mechanism “similar to centerbody stabilized”

– If true….correlation work for CB Stabilized

• Damköhler scaling seems to capture behavior

• e.g., work of Lefebvre, others

• e.g., Shanbhogue, Husain, and Lieuwen


Damköhler Scaling

Ballal and Lefebvre, 1979 Shanbhogue, Husain, and Lieuwen, 2009

16.0

150/25.0 1

'14.0125.2

gcoT

oLBO

BDeTP

uU


5

Research Questions

Major Question



Related Question #1

To What Extent do “Damköhler Type” expressions (based

mainly on bluff body stabilized flames) apply to “small” wall

recesses and/or perturbations?

(Wall quenching/heat transfer mechanism should influence situation

more so than bluff body situation)


Research Questions

Major Question



Related Question #2

If the reaction holds on a wall feature, what is required to

dislodge it (experience suggests strong hysteresis)


6

Research Questions

Major Question



Related Question #3

What is role of T, P, fuel composition, and level of vitiation?


Research Questions

Major Question



Related Question #4

How does the geometry of the wall feature affect the

flameholding tendency?


7

Project Goal

• Develop design guides to predict flameholding tendencies

within premixer passages as a function of:

– Pressure

– Temperature

– Fuel Type/Composition

– %O2 in the air (vitiation levels)

– Geometry Features


Approach and Schedule


8

Approach

• Preparation

– Fuel/Module Selection*

– Fabrication

– Diagnostics / Rig Setup

– Commissioning

• Experimental Studies

• Analyze and Correlate Results

UTSR Workshop, Irvine, CA Oct 2012

*Input from OEMs in early stages of project

15/44

Preparation

• The test rig will leverage existing high pressure testing

capability developed through support of NASA, DOE, and

industry

High Pressure Test Cells

15’ x 25’


9

CAP

RM 217

P

P

P

Flow

Control

Valve

High &

Low Flow Critical

Devices (Orifice

or Venturi)

RM 217

RM 117

Natural

Gas

Supply

Line

45psig

To

Vent

Manual

Shut Off

Pneumatic

Block &

Bleed

NG

Compressor

Up To 400

psig

High Pressure

Air Compressor

0.63 lb/s

350 psig

Building Air

Compressors

(x3)

150 psig

Yellow Mass

Flow Meter

Red Mass

Flow Meter

250

kw

165

kw

65

kw

Heater

Bypass

PRIMARY AIR

4" SCH 40

SECONDARY

AIR

(0-400 SCFM)

1" SCH 40

MAIN FUEL

Integrated

Filter/Water

Separator/

Supply Tank

TT T

AIR HEATERS

Pneumatic E-Stop Ball Valves

(Near Experiment, Automatic &

Manual Trigger)

Check Valve

To

Drain

UCICL HIGH PRESSURE FACILITY 1/08AIR & NATURAL GAS SYSTEMS

High/ Low

Selector

Valve

Room

117/217

Selector

Valve

TERTIARY AIR

(0-60 SCFM)

PID CONTROLLER

PID CONTROLLER

PID CONTROLLER

4" SS

FLEX LINE

ELECTRIC E-STOP CONTROL

DAQ

Redline

Relay

Tank

P

Tank

TCPush

Button

TO VESSEL

RM 117

WINDOW

PURGE

RM 117 AIR

HOSE SUPPLY

RM 217 AIR

HOSE SUPPLY

117

217

217

4 lb/s air; 1000 deg F preheat; diluents (stored tanks)

Pressures to 18 atm


T

T

T

P

P

P

P T

Building

Make-Up

Water

Primary/

Secondary

Make-Up

Water

Pumps

Water Quench

Injector

Pump

(600 psig)

Water Quench

Injectors

Back

Pressure

Control

Valves

From

Experiment

Secondary

Water

Dropout

Tank

Water

Quench Tank

(@experimen

t pressure)

Water

Quench

Throttling

Valve &

Flow Meter

Orifice

To Stack

To Drain

Pressure

Relief Rupture

Disk

Water Quench

Radiators

UCICL HIGH PRESSURE FACILITY 1/08

WATER QUENCH & DI WATER

SYSTEMS

Overpressure

Alarm Switch

Overtemp

Alarm Switch

PID CONTROLLER

Blue Manual

1

1 Series Contacts with Fuel E-Stop Switches

Rig Spool

Cooling

D.I. WATER SYSTEM

Building DI

H2O

DI TANK

w/ Float Valve

Low Level

Alarm Switch

To

Rig

DI Pump

5-10 gpm

(300psia)

To Drain


10

Test Rig Development

• Initial test plan envisioned using an existing “go/no go” test section

5 POINT FUEL INJECTION

Mixing/ Flow development

Upstream optical access

Test feature optical access


TORCH IGNITER ON

TORCH IGNITER OFF

Flame Holding Current Project:

High Speed OH* Imaging

will be used as well

Phantom 7.2 CMOS w/

external intensifier


11

Test Conditions

Test Conditions

• Pressure: Up to 7 atm (more if possible*)

• Velocity: Up to 70 m/s (higher if possible*)

• Preheat: 500°F-1000°F (may be limited by autoignition)

• Fuel: Φ=0.6-1.0

– Hydrogen Containing Fuels (expected to be limiting case)

– Natural Gas Fuels


*Input from OEMs in early stages of project

21/44

Test Rig Development

• Initial test plan envisioned using an existing “go/no go” test section

5 POINT FUEL INJECTION

Mixing/ Flow development

2”

2” • Discussions with OEMs indicated a mismatch

with desired test conditions

• Limited to 6 atm, 60 m/s

Upstream optical access

Test feature optical access


12

Updated Test Section

• While available test section seemed attractive…..

– Too large to hit the desired velocities and pressures


?????? Updated Test

Section

2” x 2”

23/44


Velocity/Turbulence Mapping

24/44

13

• Mean Velocity


0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

2 atm, 100 ft/s

37.00

38.00

39.00

40.00

41.00

42.00

43.00

44.00

45.00

46.00

47.00

48.00

49.00

50.00

51.00

52.00

53.00

54.00

55.00

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

2 atm, 200 ft/s

56.00

58.00

60.00

62.00

64.00

66.00

68.00

70.00

72.00

74.00

76.00

78.00

80.00

82.00

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

42.00

43.00

44.00

45.00

46.00

47.00

48.00

49.00

50.00

51.00

52.00

53.00

54.00

55.00

56.00

57.00

58.00

59.00

60.00

7 atm, 200 ft/s

56

82 m/s


37

55

42

60

25/44

• u’/U



0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

2 atm, 100 ft/sAverage = 0.066

0.04

0.05

0.05

0.05

0.06

0.06

0.07

0.08

0.08

0.09

0.09

0.09

0.10

0.10

0.11

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40


0.05

0.05

0.05

0.06

0.06

0.07

0.08

0.08

0.09

0.09

0.09

0.10

0.10

0.11

0.12

0.12

0.13

0.13

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40

0.40 0.60 0.80 1.00 1.20 1.40

0.40

0.60

0.80

1.00

1.20

1.40


0.04

0.05

0.05

0.05

0.06

0.06

0.07

0.08

0.08

0.09

0.09

0.09

0.10

0.10

0.11

0.12

11%

5 5

11

5

11

26/44

14

• [HC], ppm


Fuel Distribution

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.600.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.600.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

25000.00

30000.00

35000.00

40000.00

45000.00

50000.00

55000.00

60000.00

65000.00

70000.00

75000.00

80000.00

85000.00

90000.00

95000.00

100000.00

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.600.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.600.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

24000.00

29000.00

34000.00

39000.00

44000.00

49000.00

54000.00

59000.00

64000.00

69000.00

74000.00

79000.00

84000.00

89000.00

94000.00

99000.00

7 atm, 200 ft/s 2 atm, 100 ft/s

27/44




– Insufficient flow conditioning/fuel distribution

• Need to revise injection strategy


Updated Test

Section

2” x 2”

28/44

15

Facility Air Flow = f(Vel, T, P)

Ve

loc

ity

Temperature


OEM Input: higher velocitymass flowiterate on cross section

29/44

Facility Preheating T = f(Vel, P)

Ve

loc

ity

Temperature


OEM Input: 1000 F acceptablevelocityiterate on cross section

30/44

16

Facility Heat Rejection = f(phi, Vel, T, P)

Ve

loc

ity

Temperature


Actual run times not expected to be long enough to require full heat rejection

Managing required heat rejection:

31/44





Updated Test

Section

1.76” x 0.76”

Hits velocities

at temperatures

of interest

while allowing

sufficient heat rejection 2” x 2”

32/44

17

Test Section Sizing

Is 1.76” x 0.76” cross section representative of engine premixing sections?

GE DLN


Test Section Sizing



34/44

18

Test Section Sizing

UTSR Workshop, Irvine, CA, October 2012 UTSR Workshop, Irvine, CA Oct 2012


35/44







19

=1.3 lb/s=0.59 kg/s μ (500F)=2.8x10-5 Ns/m2

Flow Development

• Previous test section had poor velocity and fuel

distributions. Attributed to short entrance length.

• The proper entrance length is calculated as:

Entrance Length Calculation:

For rectangular pipes use hydraulic diameter:

Where P is the perimeter: 2(L+W). Reynolds number is then:

Entrance length is:

Substituting in dimensions: L= 1.76" = .0447m

W= 0.76"=0.0193m


Flow Development

3” Sch 80

pipe Pipe

3”- 600lb

Flanges

½” Fuel line

2”x1”

Rectangular

Tubing

Air

Fuel

Fuel/Air

Mixture

Adapter

Insert


20






– Limited Optical Access??


2” x 2” 1.76” x 0.76”

39/44


Round base of test

feature insert allows

test feature to be

rotated

Optical windows and test

feature have same base

so that the test feature

can be moved upstream

or downstream of ignition

source


21


Pilot Fuel Port

Igniter Port

Tube-Insert

Windows

Pressure/Temperature

Ports

14”

1.76”

0.76”

Flow

Flow

Insert for turbulence

generating panel

Round windows can either be used

for optical access or test feature

inserts


Test Rig Assembly

Air

Fuel

Pilot Fuel

Test Section

with three

optical access

points on two

plains


22

Initial Test Features*

Vane/Strut- Feature

can be rotated

Reverse Step

Rivet/bolt-exposed

length can be varied

by loosening swage

fitting on underside


* Based on OEM Input

43/44

Status


Test Section Development: 80% Complete

Test Facility Interfacing: 60% Complete

Ready For Commissioning: end of 2012

Flameholder Test Section Flameholder Flow Developer

44/44

23

Status

[email protected]; 949 824 5950 x121


development of criteria for flameholding tendencies within premixer passages … · 2013-08-22 ·...

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