Full-scale trial results to qualify optimized manufacturing plan for - - PowerPoint PPT Presentation

Full-scale trial results to qualify optimized manufacturing plan for ITER Toroidal Field coil winding pack in Japan

• N. Koizumi, M. Nakahira, K. Matsui, T. Hemmi, H. Kajitani,
• M. Iguchi and T. Sakurai

Superconducting Coil Technology Group, Japan Atomic Energy Agency (JAEA) 25th Fusion Energy Conference (FEC 2014)

• St. Petersburg, 13th October 2014

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FIP/1-3

Outline

• 1. ITER Toroidal Field (TF) coil and its procurement in Japan
• 2. Technical issues and optimized manufacturing plan
• 3. Full scale trials for TF coil winding pack manufacture
• 4. Progress in TF coil series production
• 5. Summary

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16.5m

ITER magnet system

Correction coil (18 coils) TF coil (18 coils) PF coil (6 coils) CS (6 modules)

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ITER TF Coil

Inboard Outboard

Coil case (200 tons) Winding pack (110 tons)

Regular double pancake (DP) (5) Side DP(2)

TF conductor (Nb3Sn CICC) Cover plate (CP) Insulation around DP Turn insulation RP groove to insert conductor Laser welding between RP and CP

Cross-sectional view of a TF winding pack (WP) (Inboard) 9m 16.5m

Nominal field = 11.8T Nominal current = 68kA

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Toshiba

MHI (Melco & HHI)

JAEA

Full-scale trials

Scheme of TF coil procurement in Japan

Full-scale trials 4 TF coils 5 TF coils

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 To recover from delay by disaster in Japan in 2011 and to meet ITER schedule, JADA is building two lines for manufacturing 9 TF coils.

Outline

• 1. ITER TF coil and its procurement in Japan
• 2. Technical issues and optimized manufacturing plan
• 3. Full scale trials for TF coil winding pack manufacture
• 4. Progress in TF coil series production
• 5. Summary

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Challenge in TF coil WP manufacture

TFMC （EDA, 2001） 4m 3m

 Basic technique of TF coil manufacture was demonstrated by TF model coil (TFMC) development during ITER-EDA.  Although TF coil ≈ 3.5 X TFMC, tolerances of TF coil ≈ those of TFMC.  Allowable strain of TF superconductor <0.1%  Tight tolerance is challenging.

9m 16.5m ITER-TF coil

Most critical challenge (Transfer)  TF conductor elongation after heat treatment ≈0.05%  Other sources originating error; Winding, RP and dimension measurement  Gap between conductor turn insulation and RP groove surfaces = 1mm or 1.5mm  Original tolerance ≈ 0.02% in length

110mm

Transfer RP Conductor with turn insulation

Solution of challenge in transfer

 To enable transfer, manufacturing plan is optimized. 1. High accuracy winding technique using optical measurement system. (Target accuracy = 0.01%) 2. Highly accurate prediction of conductor elongation by heat treatment (HT). (Target accuracy = 0.02%) 3. 4 RP sub-assemblies are assembled to fit RP groove length to heat-treated winding length. (Relaxed tolerance in conductor length ≈0.04%)

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Encoder Thin scratch 3m Conductor CCD camera Laser marker Winding head To winding table

Optical measurement system during winding +/-2.7mm +/-2.8mm

Machined after welding

New RP manufacturing procedure

10 RP sections (Machined in parallel) After HT 4 RP sub- assemblies

BP AP

Optimized TF coil manufacture procedure

RP Elongation by hat treatment Pancake Transfer (RP insertion) RP Winding Heat treatment (650oC, >100h)

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TF coil case: RP Turn insulation Winding pack (WP) Assembly of WP & coil case Transfer (Turn insulation) TF conductor: CN, JA, KO (EU, RF, US) 10 RP sections

4 RP sub- assemblies

Outline

• 1. ITER TF coil and its procurement in Japan
• 2. Technical issues and optimized manufacturing plan
• 3. Full scale trials for TF coil winding pack manufacture
• 4. Progress in TF coil series production
• 5. Summary

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Winding & dimension measurement (0.02%) Achieved tolerance

Strategy to accelerate full-scale trials to start series production

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Transfer Winding (0.01%) Heat treatment (HT) (0.02%) Existing regular RP (Tolerance of conductor transfer to RP is 0.02%) RP dimension measurement (0.01%) Dummy rDP winding 1st full-scale trial Transfer TF coil manufacture until transfer Prediction of conductor elongation (0.02%) Start of winding of 1st TF coil Proto sDP winding HT of sDP Good uniformity of elongation (0.01%) 2nd full-scale trial Transfer

(Final confirmation)

Winding machine qualification

 Commissioning was completed in September 2013.

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Winding table Rotation Movable Uncoiler Winding head Optical system

Winding by new winding machine

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Dummy regular DP (rDP) winding

 Dummy regular DP (rDP) winding was successfully completed at beginning

• f November 2013.

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Dummy side DP (sDP) winding

 Proto sDP winding was also successfully completed at end of November 2013.

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Accuracy of winding dimension

Accuracy of winding < 0.01% Dummy rDP (1st trial) Proto sDP (2nd trial)

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P1 P11 N1 N11 Conductor

P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2

• 100
• 80
• 60
• 40
• 20

20 40 60 80 100

Deviation of condutor length in each turn (ppm)

Turn number P10 P11 N10 N9 N8 N7 N6 N5 N4 N3

• 100
• 80
• 60
• 40
• 20

20 40 60 80 100

Deviation of condutor length in each turn (ppm)

Turn number

RP transfer (RP insertion between pancakes)

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Lower pancake winding Radial plate Upper pancake winding

Turn insulation and insertion of conductor in RP groove

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Dummy rDP transfer

 Dummy conductor was inserted in RP groove after turn insulation.

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Taping heads

Heat treatment of proto sDP

 Dedicated oven was fabricated.  5 oC at 650oC was demonstrated.

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 Conductor elongation by heat treatment =0.061% +0.007/-0.005%.

Heat treatment oven Conductor elongation

N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 0.00 0.02 0.04 0.06 0.08 0.10

Elomgation of condutor length in each turn (%)

Turn number

Outline

• 1. ITER TF coil and its procurement in Japan
• 2. Technical issues and optimized manufacturing plan
• 3. Full scale trials for TF coil winding pack manufacture
• 4. Progress in TF coil series production
• 5. Summary

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TF coil winding and heat treatment

 Winding of 5 DPs for the 1st TF coil was completed.

Winding of 1st DP of JA 1st TF Coil

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Heat treatment of 1st DP of JA 1st TF coil (Elongation = 0.07% +0.006/-0.008%)

 1st DP was heat treated.

 Winding accuracy < 0.01%  Elongation < Prediction(0.06%)0.02%

P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 N10 N9 N8 N7 N6 N5 N4 N3 N2

• 100
• 80
• 60
• 40
• 20

20 40 60 80 100

1st DP 2nd DP 3rd DP 4th DP 5th DP

Deviation of condutor length (ppm) Turn number

Summary

Full-scale trials are performed to qualify the optimized manufacturing plan of ITER TF coil WP manufacture in Japan. The major achievements and progress are as follows:  High accuracy of winding to control conductor length with 0.01% was demonstrated.  Heat treatment oven was developed with highly accurate temperature control and conductor elongation is predicted to be 0.06%0.02%. From these successful achievements, JADA started series production of TF coil. The present achievements are as follows:  5 DP winding was completed with satisfying target accuracy of 0.01%.  1st DP was heat treated and elongation of conductor is within target accuracy of 0.02%. In addition, the delay from 2011 is being recovered.

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Dummy sRP trial manufacture

Welding between RP sections After welding (RP sub-assembly) Completed RP Final assembly Machining RP section Flatness of RP sections for dummy sRP

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