Dynamics of vented hydrogen-air deflagrations

JDAUBECH1 C PROUST12 D JAMOIS1 E LEPRETTE1

1INERIS Verneuil en Halatte ndash France2 UTC Compiegravegne - France

DRA - 14092011 ndash Vented H2-air deflagrations - 2

ContextRampD activities in H2 technologies in France is driven by industrial research

targeting real applications (DIMITHRY H2E HYPE )Safety management is the ldquored linerdquo and especially aiming at shaping

mitigation techniques (avoid atex control fire and explosion effects)

Explosion venting need to be considered Widely used in industry Large body of experiments Theory standards guidelines

DRA - 14092011 ndash Vented H2-air deflagrations - 3

But hellipVent dimensioning remains difficult

Some key phenomena remain obscure bull The role of flame instabilities bull Combustion of external cloudbull Interaction internalexternal explosionbull

Severe lack of experimental bull evidence bull data about vented hydrogen explosion

Purpose of this work Providing additional results about vented hydrogen-air explosions in vessels

of industrial sizes

DRA - 14092011 ndash Vented H2-air deflagrations - 4

Experimental devices

1 m3 chamber Length 185 m Diameter 094 m Vent area 015 m2

10 m3 chamber Length 573 m Diameter 16 m Vent area 2 m2

DRA - 14092011 ndash Vented H2-air deflagrations - 5

Instrumentation1 m3 chamber

Injection device 1 bottle of 5 l (filled with H2) Pressure 5 piezoresistive gauges

bull Inside 2 gauges ndash (0-10 bar plusmn 001 bar)bull Outside 3 gauges ndash (0-2 bar plusmn 0002 bar)

installed in lenses supports at 1 3 and 5 m Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame 6 ionisation gauges

320 320 320 320 450

P1

830

i1 i2 i3 i4 i6

Vent location

i5

P2

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 2

ContextRampD activities in H2 technologies in France is driven by industrial research

targeting real applications (DIMITHRY H2E HYPE )Safety management is the ldquored linerdquo and especially aiming at shaping

mitigation techniques (avoid atex control fire and explosion effects)

Explosion venting need to be considered Widely used in industry Large body of experiments Theory standards guidelines

DRA - 14092011 ndash Vented H2-air deflagrations - 3

But hellipVent dimensioning remains difficult

Some key phenomena remain obscure bull The role of flame instabilities bull Combustion of external cloudbull Interaction internalexternal explosionbull

Severe lack of experimental bull evidence bull data about vented hydrogen explosion

Purpose of this work Providing additional results about vented hydrogen-air explosions in vessels

of industrial sizes

DRA - 14092011 ndash Vented H2-air deflagrations - 4

Experimental devices

1 m3 chamber Length 185 m Diameter 094 m Vent area 015 m2

10 m3 chamber Length 573 m Diameter 16 m Vent area 2 m2

DRA - 14092011 ndash Vented H2-air deflagrations - 5

Instrumentation1 m3 chamber

Injection device 1 bottle of 5 l (filled with H2) Pressure 5 piezoresistive gauges

bull Inside 2 gauges ndash (0-10 bar plusmn 001 bar)bull Outside 3 gauges ndash (0-2 bar plusmn 0002 bar)

installed in lenses supports at 1 3 and 5 m Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame 6 ionisation gauges

320 320 320 320 450

P1

830

i1 i2 i3 i4 i6

Vent location

i5

P2

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 3

But hellipVent dimensioning remains difficult

Some key phenomena remain obscure bull The role of flame instabilities bull Combustion of external cloudbull Interaction internalexternal explosionbull

Severe lack of experimental bull evidence bull data about vented hydrogen explosion

Purpose of this work Providing additional results about vented hydrogen-air explosions in vessels

of industrial sizes

DRA - 14092011 ndash Vented H2-air deflagrations - 4

Experimental devices

1 m3 chamber Length 185 m Diameter 094 m Vent area 015 m2

10 m3 chamber Length 573 m Diameter 16 m Vent area 2 m2

DRA - 14092011 ndash Vented H2-air deflagrations - 5

Instrumentation1 m3 chamber

Injection device 1 bottle of 5 l (filled with H2) Pressure 5 piezoresistive gauges

bull Inside 2 gauges ndash (0-10 bar plusmn 001 bar)bull Outside 3 gauges ndash (0-2 bar plusmn 0002 bar)

installed in lenses supports at 1 3 and 5 m Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame 6 ionisation gauges

320 320 320 320 450

P1

830

i1 i2 i3 i4 i6

Vent location

i5

P2

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 4

Experimental devices

1 m3 chamber Length 185 m Diameter 094 m Vent area 015 m2

10 m3 chamber Length 573 m Diameter 16 m Vent area 2 m2

DRA - 14092011 ndash Vented H2-air deflagrations - 5

Instrumentation1 m3 chamber

Injection device 1 bottle of 5 l (filled with H2) Pressure 5 piezoresistive gauges

bull Inside 2 gauges ndash (0-10 bar plusmn 001 bar)bull Outside 3 gauges ndash (0-2 bar plusmn 0002 bar)

installed in lenses supports at 1 3 and 5 m Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame 6 ionisation gauges

320 320 320 320 450

P1

830

i1 i2 i3 i4 i6

Vent location

i5

P2

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 5

Instrumentation1 m3 chamber

Injection device 1 bottle of 5 l (filled with H2) Pressure 5 piezoresistive gauges

bull Inside 2 gauges ndash (0-10 bar plusmn 001 bar)bull Outside 3 gauges ndash (0-2 bar plusmn 0002 bar)

installed in lenses supports at 1 3 and 5 m Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame 6 ionisation gauges

320 320 320 320 450

P1

830

i1 i2 i3 i4 i6

Vent location

i5

P2

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 6

Instrumentation10 m3 chamber

Injection device 4 bottles of 8 l (filled with H2) Pressure 2 piezoresistive gauges

(0-10 bar plusmn 001 bar) Ignition pyrotechnical match (60 J) opposite to

vent Propagation of the flame

bull 4 ionisation gaugesbull 4 optical sensors

BRIDES B2

3200

080 m096 m192 m

Ignition sourceP1 ndash F1F2F3P2 ndash F4

P1 P2 Pressure transducers in the chamber

F1F2F3F4

Optical flame sensors

S1S2S3S4

1 m1 m1 m

S1S2S3S4

Ionisation gauges

Vent location

192 m

28 m

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 7

Main results ndash 1 m3 chamber

20 H2 in air

0

02

04

06

08

1

12

14

16

18

2

0 001 002 003 004 005 006 007 008 009 01Time since ignition -s-

Flam

e po

sitio

n -m

-

-06

-04

-02

0

02

04

06

08

Ove

rpre

ssur

e -b

ar-

flameP1mP3mP5mPinside

Exit of the flamefrom the vessel

test 10-33 (20 H2)Test 10-05 (20H2)

Classical shape with a single dome

Acoustic effect Fresh gases replaced by burnt gases ndash local effect

External explosion strong pressure burst and propagation at the speed of sound

Acoustic effect External atmosphere accelerated by the emerging flow of fresh gases

End of combustion in the vessel

Overpressure keeps on rising when the combustion is ended in the chamber

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 8

0

1

2

3

4

5

6

7

0 005 01 015 02

Time since ignition -s-

Flam

e po

sitio

n -m

-

-05

-04

-03

-02

-01

0

01

02

03

04

Ove

rpre

ssur

e -b

ar-

Exit of the flametest 105-16 (23 H2)Test 105-16 (23H2) End of

combustion in the vessel

Main results ndash 10 m3 chamber

23 H2 in air

External explosion Pressure rises sharply before the end of combustion in the tank

Pressure decrease

First pressure bulge Combustion in the chamber

First acoustic mode of the chamber

Natural vibration of metallic envelope

DRA - 14092011 ndash Vented H2-air deflagrations - 9

Conclusion Typical industrial question How do the data compare to the standards

Absolute necessity to refine our knowledge of the phenomenology and to produce much more data NEXT STORY

0

1

2

3

4

5

6

7

8

9

10

[30] [30] [31] [31] [32] [32] [32] present present

Ove

rpre

ssur

e -b

ar-

MeasuredPredicted

Bauwens et al 64 m3

Pasman et al 1 m3

Kumar et al 685 m3

Present10 m3

Present1 m3

NFPA 68

DRA - 14092011 ndash Vented H2-air deflagrations - 10

Next Story

DRA - 14092011 ndash Vented H2-air deflagrations - 10

Next Story