Forschungszentrum Karlsruhe FZK - EURATOM ASSOCIATION 05/14/2005 Thomas Ihli 1 Status of He-cooled Divertor Design Contributors: A.R. Raffray, and The

Forschungszentrum KarlsruheFZK - EURATOM ASSOCIATION

05/14/2005 Thomas Ihli

1

Status of He-cooled Divertor Design

Contributors: A.R. Raffray, and The ARIES Team

ARIES MeetingUniversity of Wisconsin, Madison

June 14-15, 2005

Presented by Thomas Ihli *

* Forschungszentrum Karlsruhe, currently exchange visitor to UCSD & The ARIES Team



2

Basic divertor concept

T-Tubes in parallel+ simplified manifold possible (more space)

+ reduced number of single parts

Caps in paralleltarget main structure:ODS ferritic steel

heat exchange part:tungsten alloy

+ single parts can be tested before assembly



3

Cooling concept jetarray 1300°C

armorcap

cartridgeMultijetMultijetMultijetMultijet

Slot JetSlot Jet + larger cooling area lower averaged heat transfer coefficient sufficient



4

Refined Design

Caps less curved reduced tube-tube distance

Reinforcement+

improved assemblyof tube and connector

Total unit length:90 mm for 10 MW/m2

better flow uniformity stronger parts

small deformation

25 mm

85 mm

D = 15 mm



5

Parts of T-Tube Design

Tube (W-Alloy)

Cartridge (Densimet 18)

Cap (W-Alloy)

Armor Layer (W)

T-connector (W-Alloy)

Transition piece (Slices from W to Steel)



6

Stress Intensities for basic geometry

acceptable total stress at flow channels

maximum of stress intensities(~ 360 MPa) within design limits



7

Shielding asymmetric heat load

tor.

rad.

12 MW/m2

0 MW/m2



8

Heat load on caps (by radiation)

Temperature peak(for more than 50 %load on tube ends)

stress intensities at tube end o.k.

Heat load attube end

100%

Heat load attube end

50%



9

0

5000

10000

15000

20000

25000

0 15 30 45 60 75 90

angle [deg]

h [

W/m

2 K]

slot width 0.6 mm

slot width 0.4 mm

slot width 0.5 mm

0

10000

20000

30000

40000

50000

60000

0 15 30 45 60 75 90

angle [degree]

h [

w/m

2K]

Heat transfer coefficientInfluence of

slot width

q’ = 20 MW/m2 G/A = 48 kg/m2

dp = 0.28 MPad = 7.5 mms = 0.25 mm q’ = 10 MW/m2

G/A = 24 kg/m2

dp = 0.11 MPad = 15 mms = 0.5 mm

q’ = 5 MW/m2

G/A = 12 kg/m2

dp = 0.027 MPad = 30 mms = 0.8 mm



10

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20

heat flux (MW/m2)

tub

e d

iam

ete

r [m

m]

0%

5%

10%

15%

20%

25%

rel.

blo

we

r p

ow

er

[-]

tube diameter

relative blower power

Adjustment to various loads by scaling

q’ = 10 MW/m2 G/A = 24 kg/m2

dp = 0.11 MPad = 15 mms = 0.5 mm

d,b,l ~ 1/q’ G/A ~ q’P/Q’ ~ q’2

stressIntensities

~ const.



11

W – Fe transition

Tungsten

W-Fe Gradient Steel anchor

W-FE gradient transition:

Slices for stepwise adjustingof thermal expansion,

Brazed and/or HIPped



12

Schematic Divertor Module Design

T-Tubes (W)

Modulebody (Steel)pol.

rad.

600°C700°C

tor.

rad.wall cooling

manifold section

Co

llect

or

Co

llect

or



13

Divertor Module Design

T-Tubes (W)

Modulebody (Steel)

tor.

pol.rad.



14

Divertor Integration:

Divertor Target

Blanket Module

rad.

pol.

Independent Blanket/Divertor (if remaining breeding zone is still sufficient)

A1) Divertor Manifold box below Blanket module + Access to blanket pipes from below

same cutting/welding scheme for divertor + Simple shape for blanket

- Large cooled divertor manifold necessary - reduced breeding zone- divertor has to be disassembled from blanket

HT Shield with cut-outs for front access maintenance

X. Wang

X. Wang



15

Divertor Integration

Divertor Target

Blanket Module

rad.

pol.tor.

Independent Blanket/Divertor (if remaining breeding zone still sufficient)

A2) Divertor Manifold fits into cut-out in Blanket module + Divertor may be removed with Blanket + Access to blanket pipes from below+ Smaller divertor manifold

- Very complicated shape for blanket - Cooled divertor manifold necessary - Reduced shielding in manifold/tube area




16

Divertor Integration Options

Divertor Target

Blanket Module

rad.

tor.pol.

OPTION B:

Divertor Manifold fits into cut-out in Blanket module + Independent Blanket/Divertor+ Less neutron heating for divertor manifold

- Complicated shape for blanket - Access of blanket pipes limited (tor.)- Divertor cannot be removed without the Blanket




17

Divertor Integration Options

Divertor Target

Blanket Module

rad.

tor.pol.

OPTION C: Divertor Manifold in Blanket box

+ Lower neutron heating for divertor manifold+ No additional cooling for divertor manifold+ Thin manifold as included in blanket box+ Uncomplicated shape for blanket+ Better shielding than option A & B+ Access to blanket pipes from below

- Fix point at blanket back side - Divertor part of blanket

Slots between divertor channels at blanket box passage stress ok.



18

TOKAMAK Outboard target: cooling zones

Outboard

divertor power load685 MW

58 % neutron power42 % surface power

max. 80 % ofsurface poweron outboard 230 MW

0

1

2

3

4

5

6

7

8

9

10

0 0.5 1 1.5 2 2.5

target length [m]

he

at

flu

x [

MW

/m²]

< 4 MW/m²

< 2.5 MW/m²

≤ 10 MW/m²

L = 864 mm

L = 660 mm

L = 800 mm



19

43

1

2

OB

0

2

4

6

8

10

12

0 0.5 1 1.5 2 2.5

target length [m]

hea

t fl

ux

[MW

/m²]

600

620

640

660

680

700

720

tem

per

atu

re [

°C]

heat flux

T return channel

T supply channel = T_in finger

T_out finger

ZONE 1HHF

ZONE 2HHF

ZONE 3MHF

ZONE 4LHF

600°C

644°C

673°C

687°C 700°C

LAYOUT EXAMPLE TOKAMAK:thermo-hydraulic layout ΔT = 100 K



20

SUMMARY

Divertor Design Concept for ARIES CS has been developed

• New T-tube heat exchanger design • New manifold concept for rel. high neutron load (vol. heating)• Slot based jet impingement adapted• Good therohydraulic performance (Said & Regina FZK)• Thermal stress within design limits for 10 MW/m2

• Different Integration concepts can be chosen• Detailed target layout possible, when distribution data

available

Documents

Forschungszentrum Karlsruhe FZK - EURATOM ASSOCIATION 05/14/2005 Thomas Ihli 1 Status of He-cooled Divertor Design Contributors: A.R. Raffray, and The