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© ABB22 April 2023 | Slide 1
Measurement of 3D turbulent mixing in a small-scale circuit breaker model
Nils T. Basse, C. Kissing, R. Bini, M. Seeger, P. Stoller, T. Votteler and B. Wüthrich
ABB Corporate Research Center, Baden-Dättwil, Switzerland
XVIII GD, Greifswald, Germany, 2010
© ABB22 April 2023 | Slide 2
Outline
How does a self-blast gas circuit breaker work?
Earlier studies and open questions
Optical setup and test device
Discharges
Shadowgraphy movies
Streamlines from velocimetry
Conclusions and outlook
© ABB22 April 2023 | Slide 3
How does a self-blast gas circuit breaker work?
© ABB22 April 2023 | Slide 4
Earlier studies and open questions
Mixing in 2D slab geometries:
R.Bini et al.,”Measured and simulated SF6 mixing behaviour”, GD 2010 (A2 Monday 3:00 pm)
R.Bini et al., ”Arc-induced turbulent mixing in a volume filled with SF6”, submitted to J.Phys.D: Appl. Phys. 2010
N.P.T.Basse et al., ”Measured turbulent mixing in a small-scale circuit breaker model”, Applied Optics 2009
Open questions:
Diagnostics: Can we use Fresnel lenses?
Mixing: What changes from 2D to 3D?
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Optical setup
18 µs between frames, 1 µs exposure time
128 (width) × 256 (height) pixels
1 pixel = 0.6 mm
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Test device
Left: Picture of experimental setup
Right: Sketch of heating volume cuboid
Current path Heating volume
Arc zone
50.4 mm
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Discharges
Left: Current
Right: Arc voltage
-10 -8 -6 -4 -2 0 2 4-1
0
1
2
3
4
5
6
7
Time [ms]
Cu
rre
nt [
kA]
Shot 26Shot 25
-10 -8 -6 -4 -2 0 2 4-200
0
200
400
600
800
Time [ms]
Arc
vo
ltag
e [V
]
Shot 26Shot 25
© ABB22 April 2023 | Slide 8
Discharges
Left: Arc zone pressure
Right: Heating volume pressure
-10 -8 -6 -4 -2 0 2 40.8
1
1.2
1.4
1.6
1.8
2
2.2
Time [ms]
Arc
zo
ne
pre
ssu
re [b
ar]
Shot 26Shot 25
-10 -8 -6 -4 -2 0 2 40.8
1
1.2
1.4
1.6
1.8
2
2.2
Time [ms]
He
atin
g v
olu
me
pre
ssu
re [b
ar]
Shot 26Shot 25
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Shadowgraphy movies
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Streamlines from velocimetry
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Streamlines at CZ
Shot 26, time = -0.00400 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
Shot 25, time = -0.01200 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
© ABB22 April 2023 | Slide 12
Conclusions
3D mixing experiments have been done in air at 1 bar
It is possible to perform velocimetry on images recorded with Fresnel lenses
Mixing pattern at CZ:
Low current: One vortex
High current: Several vortices
© ABB22 April 2023 | Slide 13
Outlook
Future work:
Diagnostics:
Phase-contrast imaging to (i) increase sensitivity and (ii) measure absolute density
Use high quality optical components to optimise images
Test devices:
Heating volume cuboid, fixed contacts (ignition wire):
Asymmetries (current path, manufacturing inaccuracies etc.)
Other gases, fill pressures, arcing times, geometries
Christopher Kissing: RFH Köln, M.Sc. Thesis work
Heating volume cylinder, moving contacts:
Roger Wiget: ETH Zürich, M.Sc. Thesis work
© ABB22 April 2023 | Slide 15
Repeat shots: Low current movies
© ABB22 April 2023 | Slide 16
Repeat shots: Low current streamlines
© ABB22 April 2023 | Slide 17
Low current streamlines at CZ
Shot 24, time = -0.01000 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
Shot 26, time = -0.00400 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
© ABB22 April 2023 | Slide 18
Repeat shots: High current movies
© ABB22 April 2023 | Slide 19
Repeat shots: High current streamlines
© ABB22 April 2023 | Slide 20
High current streamlines at CZ
Shot 25, time = -0.01200 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
Shot 30, time = 0.00000 ms
Width [mm]
He
igh
t [m
m]
20 30 40 50 60
20
40
60
80
100
120
