SOFT 2004

OVERVIEW OF CRYOGENIC TECHNOLOGY FOR THE THERMONUCLEAR FUSION

P. DAUGUET, M . BONNETON, P. BRIEND, F. DELCAYRE, B . HILBERT, A . RAVEX

Air Liquide – Advanced Technology Division – France

pascale.dauguet@airliquide.com

Paper Summary

• Needs of the Thermonuclear Fusion programs in terms of Cryogenics

• Example : KSTAR cryogenic system prestudy

• Pictures of cryogenic equipments for Thermonuclear Fusion programs : IPR (India)

Needs of the Thermonuclear Fusion programs in terms of Cryogenics

• Cooling power at different temperatures for :

• Thermal shields : 80 K

• Superconducting Magnets : 4,5 K

• Cryopumps : 3,8 K

• Storage systems (LN2, LHe)

• Distribution systems (valves boxes, vacuum insulated transfer lines)

• Cryopumps

Example list

PROJECT Date Type of material / studies

ITER 1993-1994 Design study of Cryopump prototype’s testing on HELITEX facility at KFK

NET TEAM (ITER) 1997-1999 Design, manufacturing, installation and testing of prototype cryopump

FZK (ITER) 1999-2000 Test facility (cryostat) for cryopump model test

IPR (SST-1 TOKAMAK) 1998-2002 Design, manufacturing, installation and testing of refrigeration system (650 W at 4.5 K + 200 l/h)

W7-X 1996-1997 Preliminary study of the cryogenic system

KBSI (KSTAR) 1999 Preliminary study of the cryogenic system

W7X 2002 Preliminary study of the thermal shields

KBSI (KSTAR) 2002-2003 Engineering Design of the thermal shields

IPR (NBI of STT-1) 2002-2003 Design, manufacturing and installation of refrigeration system for Neutral beam injector (NBI) 110 W at 3,8 K.

KBSI (KSTAR) 2003-2004 Engineering Design of the cryogenic system

CEA (ITER) 2003-2004 Helium Refrigerators operating scenario study

ExampleKSTAR Cryogenic System Prestudy

KSTAR Cryogenic System Operating modesNormal operating modes

•Idle (14 hrs/day)

• Ramp (1hr/day)

•  Shot / Stand-by (8 hrs/day)

•  De-Ramp (1hr/day)

• Idle (14 hrs/day)• Baking mode (1/week)

00 08 09 17 18 24

TF

Co

il C

urr

ent

(kA

)

Plasma Experiments35

-35

0

70 sec shot per 20 minutes350 sec shot per 1 hour

• Idle Mode (18 ~ 08) • Operational State (09 ~ 17)

Process Cryogenic system diagram

Gas Storage

Cold Box

Distribution Valve Box

Compression Station

Liquid Helium Storage

Transfer lines

Oil removal system

Process Total refrigeration power vs Operating mode

Operating mode Shot/stand-by

Idle Ramp/ Deramp

Thermal Shields 18 kW 18 kW 18 kW

Isothermal Refrigeration@ 4.4K

5.5 kW 2.6 kW 4.8 kW

Liquid Helium to Current Leads

23 g.s-1 19 g.s-1 20 g.s-1

Total Exergy@4.5KdEx=(dH–T0dS) 4.5/300

9 kW 5.7 kW 8 kW

Time/day 8 hrs/day 14 hrs/day 2 hrs/day

Process Refrigerator Design Mode

Operating mode Shot/stand-by Idle

Total Ref. Power 7 kW 7 kW

Liquid Helium production

2 g.s-1 32 g.s-1

% Refrigeration 97 % 54%

Liquid Helium to Current Leads

23 g.s-1 19 g.s-1

Liquid Helium storage

-21 g.s-1 +13g. s-1

(+5000 liter/day)

Process Helium Balance

Gas Storage

Cold Box

Distribution Box

Compressor Station

LHe Storage +/- 5000 liters

Transfer lines

To C.L.

Shot/stand-by mode

Refrigeration

ProcessPFD

Cold box components :

• HX 12 sections / 3 blocks

• LN2 precooler

• 6 cryogenic Turbo-expanders

• Cold adsorbers (80K / 20 K)

T1

ProcessPFD 300K-20K

HPMPLP

300K

80K

55K

22K

HX01

HX04

HX06

HX08

T1

T2

T3

T4

80K Adsorber

LN2 Precooler

ProcessPFD 20K-4.4K HPMPLP

HX09

HX10

HX12

LHe Storage

12K

22K

4.5K

Thermal damper 4.4K

20K Adsorber

To Current leads

To / from S.C. Bus

T5

T6

HEAT LOADS :

•TF, PF, CS coils /struct.

•DB : circulators, valves, piping

•Transfer lines

Overall Cryogenic System

COLD BOX

DISTRIBUTION BOX CRYOSTAT

CURRENTLEADS

• Thermal damper, • Heat exchangers, • Circulators,• Valves.

• Cycle heat exchangers,• Expansion turbines,• Adsorbers,• Valves.

LIQUID HELIUM DEWAR

COMPRESSION STATION

BUFFER CAPACITY

• Cycle compressors,• Oil removal system,• Control valves.

HELIUM INVENTORYMANAGEMENT SYSTEM

• Compressor,• Balloon,• Purifier,• Helium gas storage.

Pure heliumImpure helium

Vacuum insulatedtransfer line

TL1

TL3

TL2

TL

TL4

Pictures of cryogenic equipments for Thermonuclear Fusion programs :

IPR (INDIA)

Compressors Cold box

Purifier, cryogenic lines and dewar 2500L

Valve box of Tokamak

PHOTO SHOW

Conclusion

As partners to fusion programs

Cryogenic industries provide :– Feasability studies and,

– Equipments

like :– N2 and He refrigerators

– Storage and distribution systems

– Cryopumps …