September 24-25, 2003 HAPL meeting, UW, Madison 1 Armor Configuration & Thermal Analysis...

September 24-25, 2003 HAPL meeting, UW, Madison

1

Armor Configuration & Thermal Analysis

1. Parametric analysis in support of system studies

2. Preliminary scoping analysis of the use of a porous armor layer

A. René Raffray

UCSD

HAPL Program Meeting

University of Wisconsin, Madison

September 24-25, 2003


2

Integrated Chamber Armor/FW/Blanket Analysis Required for Chamber System Studies

• Chamber engineering constraints are set by limits on maximum temp. and cyclic temperature behavior of armor (W) and of structural material (ferritic steel), which depend on:• IFE system parameters

– e.g. yield, rep rate, chamber size, protective gas density

• Chamber first wall and blanket design parameters for example configuration- e.g. coolant inlet and outlet temperatures, first wall structural material thickness,

armor thickness and properties (including engineered materials) and heat transfer coefficient at coolant

• Use RACLETTE-IFE code in conjunction with photon and ion energy deposition models to provide series of runs to be used as input data for system studies- Update code to include a second layer in the geometry

for modeling W + FS wall with a convective boundary condition at the coolant interface

- Add capability to model over many cycles- Compare with other modeling results for consistency

Coolant

FSW

q


3

Example Results Comparing W Temperature Histories for Armor Thicknesses of 0.05 mm and 0.5 mm, respectively

154 MJ yieldNo gas Rep Rate =10Rchamber = 6.5 mFS = 2.5mmTcoolant= 500°C

0

500

1000

1500

2000

2500

3000

3500

0 1 2 3 4 5 6 7 8 9

Time (s)

0.05mm Tungsten armor

Density = 19350 kg/m3

2.5 mm FS layerCoolant Temp. = 500°C

h =10 kW/m2-K154 MJ DD Target SpectraRep rate = 10

0

500

1000

1500

2000

2500

3000

3500

0 1 2 3 4 5 6 7 8 9

Time (s)

0.5-mm Tungsten armor



h =10 kW/m2-K154 MJ DD Target SpectraRep rate = 10

W=0.05mm W=0.5mm

• Not much difference in maximum W temperature and in number of cycles to ramp up to the maximum temperature level Coolant (h)

FSW

q


4

Example Results Comparing FS Temperature Histories for W Armor Thicknesses of 0.05 mm and 0.5 mm, respectively

500

550

600

650

700

750

800

0 1 2 3 4 5 6 7 8Time (s)

0.05 mm W armor(19350 kg/m3)

2.5 mm FS layer

Coolant T= 500°C; h =10 kW/m2-K154 MJ DD Target; Rep.rate = 10

W/FS interface

FS at coolant

154 MJ yieldNo gas Rep Rate =10Rchamber = 6.5 mFS = 2.5mmTcoolant= 500°C

500

550

600

650

700

0 1 2 3 4 5 6 7 8Time (s)

0.5-mm Tungsten armor



h =10 kW/m2-K154 MJ DD Target SpectraRep.rate = 10

W/FS interface

FS at coolant

• Substantial differences in max. TFS and cyclic TFS at FS/W interface depending on W

• Can adjust Tmax by varying Tcoolant and hcoolant

• Design for separate function and operating regime:- armor function under cyclic temperature conditions- structural material, coolant and blanket operation designed for

quasi steady-state

W=0.05mm W=0.5mm


5

H

H

H

H

HH

600

650

700

750

800

850

0

20

40

60

80

100

120

140

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Rchamber

=6.5 m

Tcoolant

=500°C

Yield = 154 MJRep. Rate = 10δW = 1 mmδFS = 2.5 mm

Armor Region Thickness (mm)

Max. TFS

Max. ΔTFS

Maximum TW, TFS, TFS as a Function of Armor Thickness for Example Parameters

• Must be integrated with chamber system modeling for consistent overall blanket and armor design parameters

• For given IFE conditions and chamber parameters, set maximum possible W (to minimize cyclic TFS and FS Tmax and provide lifetime margin) that would accommodate:- maximum allowable TW

- fabrication

• Maximum W temperature is virtually constant over range of armor thicknesses, ~ 3050°C


6

Procedure for Parametric Armor Analysis• Utilize consistent parameters from steady state parametric study of example

blanket/FW/power cycle configuration (FS/Li/Brayton Cycle)- parameters evolved on the basis of maximizing cycle efficiency while

accommodating max. allowable TFS (~800°C for ODS FS) and TFS/Li (~600°C)

- Tcoolant, convective heat transfer coefficient, and FS thickness set

• 1-mm W thickness assumed for analysis - maintain TFS <~20° C for example cases - also applicable for higher energy density cases as increasing the W thickness in the

range of ~1 mm has only a ~10°C effect on the max. TW

- could be regarded as a mid-life or end of life scenario also

• For given fusion power from blanket analysis, calculate combination of yield, chamber radius and protective gas density which would maintain max. TW < assumed limit (2400 °C)- Utilize D. Haynes/J. Blanchard’s approximation to account for gas attenuation- Reduction in photon/burn ion/debris ion of 9%/1%/29% for 10mtorr Xe and R=6.5 m- Reduction of 16%/2%/48% for 20mtorr Xe and R=6.5 m- Conservative assumption: shift ion energy spectrum correspondingly- Heat in gas reradiated to surface over time 300-700 s


7

B

B

B

J

J

J

H

H

H

F

F

F

11

1

é

é

é

é

éé

é éé é

0

10

20

30

40

50

60

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400 450

Yield (MJ)

1 mm W3.5 mm FST

coolant=572°C

h=67 kW/m2-K

Required PXe as a Function of Yield to Maintain TW,max<2400°Cfor 1800 MW Fusion Power and Different R

chamber

Rchamber (m)5.7

6.5

7

8

10

Summary of Armor Parametric Results for a Fusion Power of 1800 MW

• These results are used as input in the system code in combination with results from the blanket/FW/cycle parametric analysis for the given fusion power

Example target survival constraints based on allowable q’’ for case with 100m 10% dense foam and 4000 K Xe (& 16 K target)


8

B

B

J

J

H

H

é

é

é

é

éé

éé

éé

0

5

10

15

20

25

30

35

40

0

10

20

30

40

50

60

0 50 100 150 200 250 300 350 400 450

Yield (MJ)

1 mm W3.5 mm FST

coolant=547°C

h=60 kW/m2-K

Rchamber (m)

Required PXe

as a Function of Yield to Maintain TW,max<2400°C for

3000 MW Fusion Power and Different Rchamber

7

10

8

Summary of Armor Parametric Results for a Fusion Power of 3000 MW


9

Scoping Study of Thermal Performance of Armor with a Porous Layer

- PPI plans to develop nano-scaled engineered W for armor applications as part of current SBIR Phase I grant• Work with PPI to help optimize material microstructure

characteristics (e.g. microstructure characteristic dimension, porosity, pore sizes, heterogeneity)– Minimize resistance to migration and release of implanted He

– Provide adequate heat transfer performance

– Use RACLETTE-IFE with adjusted material property data and energy deposition input to help understand impact on integrated chamber armor/FW/blanket system


10

0x100

1x1010

2x1010

3x1010

4x1010

5x1010

6x1010

7x1010

1x10-8 1x10-7 1x10-6 1x10-5 1x10-4

0.2

0.8

0.5

Penetration depth (m)

0

W density = 19,350 kg/m3

Porous armor regionthickness = 10 μm

Porous armor regionporosity:

Ion Energy Deposition as a Function of Penetration Depth for a W Armor with a 10m Porous Layer

• Maximum energy deposition decreases and energy penetration depth increases with increasing porosity of the porous layer


11

1000

1500

2000

2500

3000

3500

4000

4500

0 10 20 30 40 50 60 70 80 90 100

50%

Maximum TW as a Function of Armor Porous Region Thickness

for Different Porosities

Rchamber

=7.5 m = 1800 Fusion Power MW

= 154 Yield MJW = 1 mmFS = 3.5 mm

:Porosity

(Porous Region Thickness )m

20%

10%

0%

Ion Energy Deposition as a Function of Penetration Depth for a W Armor with a 10m Porous Layer

• For these scoping calculations, fully dense k and of W scaled to density of porous region

• Maximum armor temp. increases appreciably with increasing porosity but not with porous region thickness past ion penetration depth (<10m)

• Important to minimize porosity of porous region but there is flexibility in setting its thickness

• Porous region might reduce peak thermal stresses on armor and allow for higher max. temp. limits


12

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0

500

1000

1500

2000

2500

3000

3500

4000

4500

xporous = 10 m

50% q''' for porosity k and rho for fully dense

xporous = 100 m

q''' for fully dense k and rho for50% porosity

, q''' k and rho for50% porosity

= 154 Yield MJ = 1800 Fusion power MW

Rchamber = 7.5 m

W= 1 mm

FS = 3.5 mm

Assessing Relative Effects of Decrease in Thermal Conductivity and Density and Change in Ion and Photon Energy

Deposition Profile in Porous Region

• Effect on max. TW of decrease in k in porous region dominates opposite effect due to broadening of energy deposition

• Similar results for different thicknesses of porous region (10 and 100 m)


13

Conclusions

• Scoping study of thermal performance of porous armor region has been performed - Max. TW dependent on porosity of porous region but virtually not on its

thickness (past energy deposition depth)

- Effect of lower thermal conductivity of porous region outweighs counterbalancing effect of energy deposition spread in porous region

- Optimization of porous material based on providing least resistance to migration of implanted He ions while accommodating maximum W temperature constraint (i.e. providing acceptable heat transfer performance)

• Parametric study of armor performed to provide input for initial system studies - W thickness affects TFS at FS/W interface but virtually not max. TW

- Design armor based on transient conditions and FW and blanket based on quasi steady-state conditions

- Study has yielded combination of yield, chamber radius and protective gas density which would maintain max. TW < assumed limit (2400 °C) for

different fusion powers and consistent blanket/FW/cycle parameters

September 24-25, 2003 HAPL meeting, UW, Madison 1 Armor Configuration & Thermal Analysis...

Documents

Transcript of September 24-25, 2003 HAPL meeting, UW, Madison 1 Armor Configuration & Thermal Analysis...