High-Pressure Turbulent Flame Speeds and … Library/Events/2015/utsr...Eric L. Petersen Department of Mechanical Engineering Texas A&M University High-Pressure Turbulent Flame Speeds

Eric L. PetersenDepartment of Mechanical Engineering

Texas A&M University

High-Pressure Turbulent Flame Speeds and Chemical Kinetics of Syngas Blends With and

Without Impurities

2015 University Turbine Systems Research WorkshopAtlanta, GA

3-5 November, 2015

3-Year Project Began in October, 2013

Project Overview

Project Highlights:

1. Duration: Oct. 1, 2013 – Sept. 30, 2016

2. DOE NETL Award DE-FE0011778

3. Budget: $498,382 DOE + $124,595 Cost Share

4. Principal Investigator: Dr. Eric L. Petersen

Project Overview

This Project Addresses Several Problems for HHC Fuels

1. Improve NOx kinetics for High-Hydrogen Fuels at Engine Conditions

2. Effect of Contaminant Species on Ignition and Flame Speed

3. Impact of Diluents on Ignition Kinetics and Flame Speeds

4. Data on Turbulent Flame Speeds at Engine Pressures

Project Overview

There are Five Main Work Tasks for the Project

Work Tasks:

Task 1 – Project Management and Program Planning

Task 2 – Turbulent Flame Speed Measurements at Atmospheric Pressure

Task 3 – Experiments and Kinetics of Syngas Blends with Impurities

Task 4 – Design and Construction of a High-Pressure Turbulent Flame Speed Facility

Task 5 – High-Pressure Turbulent Flame Speed Measurements

TAMU Work is a Team Effort of Several People

Dr. Olivier Mathieu

Anibal Morones

Charles Keesee

Clayton Mulvihill

5

Project Overview


1-atm Turbulent Flame Speed Measurement will Build Upon Tests Done in Previous UTSR Project

• Utilize Existing Turbulent Flame Speed Hardware

• Extend Test Conditions to a Range of u' and Length Scale Values

• Detailed Characterization of Existing Conditions with LDV

• Perform Experiments for Syngas Blends at 1 atm Conditions

Task 2 – Turbulent Speeds

Existing 1-atm Rig Characterized for 1 Main Condition


Features:

• 7075-T6 Heat-Treated Aluminum

• 4 radial impellers

• Diameter: 30.5 cm

• Length: 35.6 cm

• Window Port Diameter: 12.7 cm

• Maximum initial pressure: 1 atm

• Maximum initial temperature: 298 K

Turbulence:

• Intensity: 1.5 m/s rms

• Integral length scale: 27 mm

Gasket

Wi ndow

Spacer

(De Vries 2009)

Task 2 – Turbulent SpeedsExisting Rig Has 4 Fans Centrally Located, Added toOriginal Rig of de Vries (2009)

Device Model

Transceiver PowerSight TR-SS-2D

Signal processor FSA4000-2

Traverse Isel T3DH

Photomultiplier PDM1000-2SS

Particle Generator 9306

Computer Dell Precision T7600

Task 2 – Turbulent SpeedsLDV Setup from TSI

Task 2 – Turbulent SpeedsOptics Alignment

Collocating the probe volume and the receiving optics

LDV transceiverfocusing lens

Window assembly

Focal length or standoff


Test region6×6×6 cm3

Task 2 – Turbulent SpeedsTiming Sequence Controlled to Capture Turbulence

Test region average: horizontal 1.60 m/s; vertical 1.63 m/s

1.65

1.6

1.55

1.7

1.7

1.75

1.75

1.8

1.5

1.75

1.8 1.

751.

85

Horizontal Axis [mm]

Ver

tical

Axi

s [m

m]

Horizontal turbulence fluctuationXY Cross section at Z =0mm

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30m/s

1.5

1.55

1.6

1.65

1.7

1.75

1.8

1.85

1.651.6

1.71.75

1.55

1.81.85

1.7

1.9

1.75

1.7

1.8

1.95

1.75


Ver

tical

Axi

s [m

m]

Vertical turbulence fluctuationXY Cross section at Z =0mm

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30m/s

1.55

1.6

1.65

1.7

1.75

1.8

1.85

1.9

1.95

122 2

,1

1( ) ( ) ( ( ; ))N

i rms i i nn

u u u tN =

= = ∑x x x

Task 2 – Turbulent SpeedsTurbulent Fluctuation rms Results

USC simulationsAgreement with numerical model

Reference Technique Turbulencefluctuation

Averagevelocity

(Ravi, Peltier et al. 2013) PIV 1.48 0.03

(Davani and Ronney 2015) Simulation 1.63 0.12

This work LDV 1.62 0.40* *axial

Isotropy test region average 0.98

,

,

( )( ) i rms

ii rms

uH

u=

xx ,

,

( )( )

( )x rms

xyy rms

uI

u=

xx

x

1

1.05

1.05

0.951.

1

1.1

1.1

1.15

1.1


Ver

tical

Axi

s [m

m]

Horizontal turbulence fluctuation homogeneityXY Cross section at Z =0mm

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30

0.94

0.96

0.98

1

1.02

1.04

1.06

1.08

1.1

1.12

1.14

, ,1

1 ( )M

i rms i rms mu uM

= ∑ x

0.9

0.95

0.95

1

1

1

1.05

1.05

0.9


Ver

tical

Axi

s [m

m]

Turbulence fluctuation isotropyXY Cross section at Z =0mm

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

1.04

Task 2 – Turbulent SpeedsTurbulence Homogeneity and Isotropy

Run # LocationIntegral time scale [ms] Taylor microscale [ms]

Horizontal Vertical Horizontal Vertical285 0, 0, 0 13.5 12.5 0.60 0.45

1112 30, 0, 0 10.2 8.5 0.53 0.38943 -30, 0, 0 10.5 8.8 1.66 0.46

1015 0, 30, 0 11.3 11.6 1.36 2.091040 0, -30, 0 13.2 15.9 1.9 1.95

436 0, 0, 30 12.4 11.4 1.85 1.951592 0, 0, -30 10.1 9.9 1.43 1.43

Integral time scale comparable to flame experiment duration

0

( )t r dτ τ∞

Λ ≡ ∫2

22

0

2tr

τ

λτ

=

∂≡ −

∂


-40 -30 -20 -10 0 10 20 30 40-40

-30

-20

-10

0

10

20

30

40

Average velocityXY Cross section at Z =0mm

Horizontal (X) Axis [mm]

Ver

tical

(Y) A

xis

[mm

]

Task 2 – Turbulent SpeedsResults Indicate a (Slow) Overall Vortex Pattern

• Radial pattern

• Test region average 0.58 m/s

0.50.6

0.7

0.4

0.80.9

0.3

0.2

0.8

1

0.8

1.1


Ver

tical

Axi

s [m

m]

2D average velocityXY Cross section at Z =0mm

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30m/s

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

Task 2 – Turbulent Speeds2-D Average Velocity Results

1. Results agree qualitatively with the previous work of Ravi (2013).

2. HIT turbulence confirmed

3. Extension of measurements to a 3-D region revealed unfavorable characteristics previously missed.

4. The axial component found to have a resultant mean flow of 0.4 m/s.

5. A regular polyhedron fan distribution is advised



1. Study Impurity Composition Effect

• Ignition delay time (τign) measurements in a shock tube

• Laminar flame speed measurements

• Large range of P, T

2. Kinetics Modeling of Impurities

Overall Task Has 2 Main Goals

Task 3 – Impurity Effects

1. H2S Impurity Effect on Laminar Flame Speeds for Coal Syngas

2. H2S Oxidation Kinetics and Shock-Tube Measurements

Update Today Will Focus on 2 Main ProjectsTask 3 – Impurity Effects

Vessel Internal Dimensions:

31.8 cm Diameter

28 cm Length

12.7 cm Window Diameter

High-Temperature, High-Pressure Vessel Used forLaminar Flame Experiments


Laminar Flame Speed Measurements PerformedWith H2S Impurity

• Baseline “coal” syngas: 60% CO / 40% H2

• Equivalence ratio Sweep

• Pressure: 1 atm

• H2S: 1% by Volume

• Argon instead of N2


Mixtures Investigated (Mole Fraction)

Mixture Fuel Oxidizer

CO H2 H2S O2 N2 Ar

Coal - Neat, Air 0.6 0.4 - 0.21 0.79 -

Coal - Neat, Argon 0.6 0.4 - 0.145 - 0.855

Coal - 1% H2S, Argon 0.594 0.396 0.01 0.145 - 0.855

Mixtures Investigated for Flame Speed Study


O2/Ar ratio chosen to match Flame Temp with air over same φ range

0.5 1.0 1.5 2.0 2.5 3.00

20

40

60

80

100

120

140

160

1% H2S

S°L,

u (cm

/s)

φ

NEAT

Model: NUIG mechanism with TAMU H2S kinetics

H2S Has Small Effect and Only for Rich Mixtures


0.5 1.0 1.5 2.0 2.5 3.00

20

40

60

80

100

120

140

160

180

1% H2S, Ar

NEAT, Ar

S°L,

u (cm

/s)

φ

NEAT, Air

Argon-Based Flame Speeds Noticeably Lower than N2-Based Ones


Argon-Diluted Mixture Markstein Lengths

0.5 1.0 1.5 2.0 2.5 3.0-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

Coal, Ar - Neat, Markstein Coal, Ar 1% H2S, Markstein

L b (c

m)

φ

0.5 1.0 1.5 2.0 2.5 3.0-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

L b

(cm

)

φ

Coal, Air - Neat, Markstein Coal, Ar - Neat, Markstein Coal, Ar 1% H2S, Markstein

Air and Argon/O2-Based Markstein Lengths are Similar


Shock-Tube Experiments Focused on H2S Oxidation

• H2S – O2 – Argon mixtures (98% Ar dilution)

• Equivalence ratios: 0.5, 1.0, 1.5

• Pressure: 1.7 atm

• Ignition delay times

• Water concentration time histories


High-Pressure Shock-Tube Facility

• 1 – 100 atm Capability

• 600 – 4000 K Test Temperature

• Up to 20 ms Test Time

• 2.46 m Driver and 4.72 m Driven

• 15.24 cm Driven Inner Diameter

Time-Interval Measurement

Vacuum System

Driven Section (4.72 m) Driver Section (2.46 m)

Expansion Section / Diaphragm Location

Access PortWeldless Flange6

High pressure shock-tube facility at Texas A&M


0 0.0004 0.0008 0.0012Time (s)

0

0.4

0.8

1.2

Nor

mal

ized

OH

* em

issi

on

0

1

2

3

Pres

sure

(atm

)τign

Ignition Delay Time Obtained from OH* Time History

Concave Reflecting Mirror (f)

Adjustable width slit

Optical Window

PMT

Shock tube

OH*

• A2 Σ+ (OH*) light at 307 nm

• Highly Diluted Mixtures (98% Ar)


• Control and monitoring of laser‒ Toptica Photonics DL 100: CW, narrow width laser ‒ Toptica Photonics DC 110: current and temperature control‒ Burleigh WA-1000: monitoring of laser wavelength

• Common mode rejection

• Lexan enclosures‒ Purged by N2

‒ Monitored by hygrometer‒ < 0.1% RH for all experiments

Tunable laser diagnostic used for transient H2O concentrations

Reacting gases Endwall

Reflected shock N2-flooded

environment

Lens I detector

Iris and BP filter

Laser

I0 detector

50/50 BS

90/10 BS To wavemeter


Hygrometer

Transmitted side (𝑰)

Laser

Laser controller Wavemeter

Incident side (𝑰𝟎)

• Temperature rise simulated by CHEMKIN (typically 200-300 K)

• In-house routine created to correct raw data with simulated temperature rise

• Modified mechanisms used to iterate on accurate solution

The temperature rise due to combustion causes a significant change in the absorption coefficient

0 1 2 30.12

0.16

0.20

0.24

0.28

Absorption coefficient Simulated temperature

Time (milliseconds)

Abso

rptio

n co

effic

ient

(cm

-1at

m-1)

1560 K, 1.31 atm0.008 H2S / 0.012 O2 / 0.98 Ar

1500

1600

1700

1800

1900

Sim

ulat

ed te

mpe

ratu

re (K

)


Typical OH* and H2S Time Histories Show Main IgnitionDuring Middle of Water Formation


0 500 1000 1500 2000

0.000

0.002

0.004

0.006

0.008 H2S in 98% Ar, φ=1.0

H2O (1611 K, 1.29 atm)

OH* (1620 K, 1.07 atm)

Time (µs)

X wa

ter

0.0

0.2

0.4

0.6

0.8

1.0

Nor

mal

ized

OH*

sig

nal

4.5 5.0 5.5 6.0 6.5 7.0100

1000

H2S in 98% Ar, 1 atmφ = 0.5φ = 1.0φ = 1.5Ig

nitio

n de

lay

time

(µs)

10000/T (K-1)

First Ignition Delay Time Results Obtained for H2SOxidation


• All recent literature based on model from Zhou, Haynes, et al., 2013

• Original model from Zhou et al. not in good agreement with the new set of data.

• Model from Mathieu, Petersen et al. (2014) not working well here.

• This study: fair agreement with new data and w/ former literature ST data => new meas. helpful

• Not possible to reconcile both shock tube and flow reactor data w/ current models.

5 6 710

100

1000

H2S in 98% Ar, φ = 1.0, 1 atm

Experimental data Zhou et al. (2013) Mathieu et al. (2014) Bongartz and Ghoniem (2015) Bongartz and Ghoniem (2015) - optimized for ST Mohammed et al. (2015) This study (optimized for ignition time results only)

Igni

tion

dela

y tim

e (µ

s)

10,000/T5 (K-1)

Kinetics Modeling of Ignition is Ongoing…


Kinetics Model Predicts Shape of OH* Time History Rather Well


0 500 1000 1500 2000 25000.0

0.5

1.0

Norm

alize

d O

H*

Time (µs)

Normalized signal Zhou et al. (2013) This study

0 500 1000 1500 2000 2500

0.000

0.002

0.004

0.006

0.008

H2S in 98% Ar, φ = 1.0

X H2

O

Time (µs)

1515 K, 1.35 atm 1685 K, 1.29 atm 1784 K, 1.25 atm

0 500 1000 1500 2000 2500

0.000

0.002

0.004

0.006

0.008

H2S in 98% Ar

X H2

O

Time (µs)

1774 K, φ = 0.5 1784 K, φ = 1.0 1776 K, φ = 1.5

Water Time Histories Provide Valuable Information forImproving H2S Kinetics Mechanism


Effect of Temperature

Effect of φ

• All recent models predict H2O starting too early

• Mainly due to H2S + O2 = SH + HO2 (R1)

• R1 rate needs to be modified

• Rate of SH + O2 = HSO + O changed w/rate meas. in lit.

• Other rxns. suspicious (SH + SH + M = HSSH + M)

• More data at different conditions and rate measurements sorely needed!

0 500 1000 1500 2000

0.000

0.002

0.004

0.006

0.008

H2S in 98% Ar, 1611k, 1.29 atm

X W

ater

Time (µs)

Zhou et al., 2013 Bongartz and Ghoniem, 2015 Current model (work in progress)

H2O Profiles Uncovered Large Deficiencies in PreviousMechanisms…


Task 4 – Design and Construction of a Turbulent Flame Speed Facility

Task 4 – New Facility

Borghi Diagram shows Current and Desired Regions for Turbulent Flame Speeds

New Facility Will be Designed and Built at TAMU

1. Detailed Design and Structural Analysis

2. Fabrication of Vessel Components

3. Installation of Vessel

4. Characterization of Flow Conditions


Task 4 Design and Installation is Underway

• Survey of Existing Turbulent Flame Speed Facilities Completed

• Trade-off Study for Final Design Finished

• Critical Aspect is how to Handle or Reduce the Overpressure

• Will Move Toward a Design that Involves a Blowout Disk and Reservoir for Overpressure

• Detail Design is Complete

• Fabrication is Underway


• Built in forged SS

• ID 14”; height 18”

• 4 windows; ∅5” aperture

• 4 stirring fans; ∅5.75”

• Max. allowable pressure: 200 atm


New Design is Complete

• Breach ∅8”

• Vented deflagration through diaphragm (top)

• Bottom breach is reconfigurable:– Heater– Injection port– Spark plug gland


Breach and Diaphragm Method Selected for Venting

• Arranged in tetrahedral configuration

• Max. speed: 10,000 rpm

• 8-bladed radial impeller with 30°pitch and 1.25” axial depth.


New Fan Design was Implemented, Based on LDVResults from Existing Rig

• Fused quartz substrate

• Two orthogonal lines of sight

• Size and proportions of window and vessel have been proven to produce data free of ignition and confinement effects.


Optical Access Allows 2 Lines of Sight and Based on Prior Experience


High-Pressure Experiments Will be Performed for Selected Syngas Blends

• Identify Two Test Matrices (Fuel Blends) for Study

• Utilize Results from Tasks 2 and 3 for Guidance

• Perform Experiments at Elevated Pressures

• Parallel High-Pressure Laminar Tests Should also be Done

Task 5 – High-Pressure Turbulence

Progress on the Five Main Work Tasks for the Project Was Presented

Task 1 – Project Management and Program Planning



Task 4 – Design and Construction of a High-Pressure Turbulent Flame Speed Facility


Summary

Recent Data Cover a Wide Range of Flamelet Regions


10-1 100 101 102 103 10410-1

100

101

102

103

CH4

Syngas50-50 CH4-H2

H2

Distributed Reactions

Thin Reaction Zone

Corrugated Flamelet

Wrinkled Flamelet

Da =1

u'

/SL

L/δl

Ka = 1Re

L = 1

u' = SLLaminarFlame

Documents

High-Pressure Turbulent Flame Speeds and … Library/Events/2015/utsr...Eric L. Petersen Department of Mechanical Engineering Texas A&M University High-Pressure Turbulent Flame Speeds