Temperature evolution in the spray zones: plant

ANNUAL REPORT 2008UIUC, August 6, 2008

Xiaoxu Zhou (MS Student)Brian G. Thomas

Department of Mechanical Science and Engineering

University of Illinois at Urbana-Champaign

Temperature evolution in the spray zones:

plant measurements and CON1D prediction

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Xiaoxu Zhou 2

Acknowledgements

• Continuous Casting Consortium Members (Baosteel, Corus, Goodrich, Labein, LWB Refractories, Mittal, Nucor, Postech, Steel Dynamics, Ansys Inc.)

• National Science Foundation– GOALI DMI 05-00453 (Online)

• Other graduate students, especially Huan Li and Bryan Petrus James.


Outline

• Nucor trials-pyrometer measurements

• Con1d prediction of Nucor trials

• Con1d prediction of whale formation

• Con1d tests of hysteresis

• Conclusions


Pyrometers location

Pyrometer 1

Pyrometer 2

Pyrometer 3

Pyrometer 4

Pyrometer 5


Pyrometer Specifications

3866.1 mmLocation of Pyrometer 4 from meniscus

13970 mmLocation of Pyrometer 5 from meniscus

6015.3 mmLocation of Pyrometer 3 from meniscus



15.5 mmFocus spot size

1346 mmLength

Modline® 5, 5R-141000, 4M5#25579Model Name and Number


Spray zones configuration in con1d input file

1 (49)

10 (39~48)

1 (38)

9 (29~37)

1 (28)

9 (19~27)

1 (18)

5 (13~17)

6 (7~12)

5 (2~6)

1 (1)

# of Rolls

0.11510995.8(11)

0.0958495.8(10)

0.0958260.0(9)

0.0956130.3(8)

0.0955903.6(7)

0.0803968.6(6)

0.0803773.6(5)

0.0702823.3(4)

0.0621767(3)

0.062940(2)

0.062850(1)

Roll Radius (m)Zone StartsZone No.


SouthCaster

Jan. 13, 2006, 1610-1640 hrs.Time of Experiment

1547.777 oCPouring Temperature

C .247Mn 1.09S 0.0019Al 0.039Ca .0018Si .175P .014Cu .087N (leco).0076

Composition of Elements (%)

4 to 7Spray Pattern Number

142.1 ipm (3.61 m/min) (0.06 m/s)Casting Speed

ValueParameter

Case 4 13 Jan Transient (Low and High Spray)

Nucor experiment (from Amar’s ccc meeting 2006)

•The casting speed kept constant.•The spray pattern went like high-low-high-low-high.


Experimental Temperature Profile

-Amar Behera’s Nucor report


Del avan 19813-3 Qw=10. 4 L/mi n

0500

1000150020002500300035004000

-60 -40 -20 0 20 40 60

Del avan 19813- 3 Qw=10. 4 L/mi n

0

20

40

60

80

100

- 60 - 40 - 20 0 20 40 60

Delavan 19813-3Distance down caster (mm)

Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)

Water flow used in nozzle experiment

Characterize using CON1D

Estimated heat flux profile based on Nozaki correlation

--from Vapalahti’s 2006 ccc meeting report:

“Delavan Nozzle Characterization at CINVESTAV”


Del avan 19813-5 Qw=6. 9 L/mi n

0

500

1000

1500

2000

2500

-60 -40 -20 0 20 40 60

Del avan 19813- 5 Qw=6. 9 L/mi n

0

5

10

1520

25

30

35

- 60 - 40 - 20 0 20 40 60


Delavan 19813-5Distance down caster (mm)

Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)






Distance down caster (mm)

Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)





Del avan 3. 5-90 Qw=8. 5 L/mi n

0

500

1000

1500

2000

2500

3000

3500

-60 -40 -20 0 20 40 60

Del avan 3. 5- 90 Qw=8. 5 L/mi n

0

10

20

30

40

50

60

- 60 - 40 - 20 0 20 40 60

Delavan 3.5-90




Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)





Del avan 51474-1 Qw=39 L/mi n

010002000300040005000600070008000

-60 -40 -20 0 20 40 60

Del avan 51474- 1 Qw=39 L/mi n

0

50

100

150

200

250

300

- 60 - 40 - 20 0 20 40 60


Delavan 51474-1



Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)





Del avan 51468-1 Qw=25 L/mi n

0

1000

2000

3000

4000

5000

6000

-60 -40 -20 0 20 40 60

Del avan 51468- 1 Qw=25 L/mi n

020406080

100120140160

- 60 - 40 - 20 0 20 40 60


Delavan 51468-1



Wat

er fl

ux (

L/m

2 s)

Hea

t tra

n C

oeff

(W/m

2K)





Del avan W19822 Qw=10. 8 L/mi n

0

500

1000

1500

2000

2500

3000

3500

-60 -40 -20 0 20 40 60

Del avan W19822 Qw=10. 8 L/mi n

0

10

20

3040

50

60

70

- 60 - 40 - 20 0 20 40 60


Delavan W19822


Con1d prediction of Nucor trails

3.61

m/min

Casting speed

h profile

0.7values

Water flow rates

Solid fraction

Spray length

Model parameters

Specific input variables:

Low High


Con1d predictions-- case 4_low spray

600

700

800

900

1000

1100

1200

1300

0 2000 4000 6000 8000 10000 12000 14000 16000

Sur

face

Tem

pera

ture

(¡ã

C)

Distance below meniscus (mm)

CON1D: Shell Surface Temperature

case4_low spray(Nucor)pyrometer #1pyrometer #2pyrometer #3pyrometer #4pyrometer #5

-Huan’s Nucor trial ppt


600

700

800

900

1000

1100

1200

1300

0 2000 4000 6000 8000 10000 12000 14000 16000

Sur

face

Tem

pera

ture

(¡ã

C)

Distance below meniscus (mm)

CON1D: Shell Surface Temperature

case4_high spray(Nucor)pyrometer #1pyrometer #2pyrometer #3pyrometer #4pyrometer #5

Con1d predictions-- case 4_high spray

-Huan’s Nucor trial ppt


Con1d predictions(steady state simulation)


Cononline Prediction(transient simulation)


Observations

• Compared to pyrometer measurements Con1d gives highertemperature prediction in the spray region except the pyrometer 2 in the case 4_low spray. In order to match pyrometer 2 measurement, the heat transfer coefficient should be increased appropriately around 6000 mm down the strand.

• Pyrometer focuses the thermal radiation onto the detector. However, there is much mist around strand which should decrease the power intensity collected by pyrometers. Then, it is the fact that pyrometer gives lower reading.

• Thus, Con1d temperature prediction matches reasonably pyrometer measurements in the spray region in these two cases.


whale formation casesCasting conditions (Nucor Dec 9, 2003)

WhaleNo Whale No WhaleObservation at Plant

611Spray Pattern

146157146Casting Speed

(ipm)

Case 3Case 2Case 1

Containment limit = 11246.0mm

Flat-top for all sparys

( z1 z2 z3 h1 h2 h3 )

(0 0.5 1.0 1.0 1. 0 1.0)

0.70.05 mm for all sprays

values

h profileSolid fraction

Spray lengthModel parameters

Specific input variables in con1d:


Con1d prediction of Case 1

0

5

10

15

20

25

30

35

40

45

0 2000 4000 6000 8000 10000 12000 14000600

700

800

900

1000

1100

1200

1300

1400

1500

Distance down meniscus,mm

Thi

ckne

ss, m

m

Tem

pera

ture

, Deg

C

Solidus Liquidus Shell surf TSolid

Note: no whale, matchthe observation



0

5

10

15

20

25

30

35

40

45

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000600

700

800

900

1000

1100

1200

1300

1400

1500


Thi

ckne

ss, m

m

Tem

pera

ture

, Deg

C


Note: Solid coincidescontainment limit.



0

5

10

15

20

25

30

35

40

45

0 2000 4000 6000 8000 10000 12000 14000600

700

800

900

1000

1100

1200

1300

1400

1500


Thi

ckne

ss, m

m

Tem

pera

ture

, Deg

C


Note: whale, matchthe observation


Con1d prediction of whale formation of case 3 using pointed h profile

3.9878

m/min

(157ipm)

Casting speed

h profile

0.7values

Water flow rates

Solid fraction

Spray lengthModel paramet

ers

Input variables:


Whale formation Con1d9.6 prediction Case3

Shel l gr owt h & Sur f t emp ( 146i pm Spr ay pat t er n_6)

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000

di st ance bel ow meni scus ( mm)

Temp

(de

g c)

0

5

10

15

20

25

30

35

40

45

50

thic

knes

s (m

m)

Sur f Temp Li qui dus Sol i dus Shel l

Whale observed in the plantfor Case 3.

But prediction gives solid far away before containment limit.

Conclusions:Heat transfer coefficients were too high

Pyrometer temperatures (which are matched by this run) were reading too low


Leidenfrost effect with hysteresis

1000

1.6

1050.900.800700.temperatures

1.02.21.21.0h-multipliers

•Con1d 9.6 was modified to consider hysteresis in Liedenfrosteffect:

•If surface temperature tsnext > ts, meaning heating, LF effect is employed.•If surface temperature tsnext<ts, meaning cooling, LF effect is not employed.

• Using the following set of h multipliers


Hysteresis effect

600

700

800

900

1000

1100

1200

0 2000 4000 6000 8000 10000 12000 14000 16000

Distance below meniscus,mm

Sh

ell

su

rfa

ce

te

mp

era

ture

, De

g

C

LF effect always ON Hysteresis employed


Hysteresis effect

600

700

800

900

1000

1100

1200

0 2000 4000 6000 8000 10000 12000 14000 16000

Distance below meniscus,mm

Sh

ell

su

rfa

ce

te

mp

era

ture

,De

g C

Hysteresis employed Hysteresis always OFF


Conclusion and future work

• Several CON1D simulations have been combined to show that pyrometer measurements maybe not believable.

• Hysteresis based on heating / cooling is oversimplified, as fluctuations between rolls made the Leidenfrost effect with hysteresis negligible in test simulations.

• Parameters are needed to simultaneously match: – lab heat extraction measurements at Cinvestav– Pyrometer temperatures or TC traces measured at plant– Whale formation / shell thickness

Documents

Temperature evolution in the spray zones: plant