L.ValdarnoTE-MSC-CMI, CERN7th October 2014

HIE-ISOLDE CryomoduleThermal Analysis – 2nd part

About the 1st part1

2

3

4

2

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

3

Objective

Targets:

1. Global temperature and heat flux mapping; 2. Design validation;3. Validation of the experimental tests;4. Simulation tool for future thermo-mechanical analysis;

« A model is a selective abstraction of the reality »• Problem formulation• Analytical estimations• FEM model• Analysis of the results

HIE-ISOLDE: Procedure

4

1. Initial status 300K structures

2. Thermal shield cool down 300K-75K 13 bar

3. Reservoir + frame cool down 300K-75K 2.5 bar

4. Reservoir + frame cool down 75K-4.5K 2.5 bar

5. Global cool down• Thermal shield circuit : 13barG, 55-75K• Cold mass circuits: 1.3 barG, 4.5K

5

HIE-ISOLDE: Model

Vacuum vessel Top plate Thermal shield Cryogenics circuit

Supporting frame assembly Actively cooled frame Suspension rods

Helium reservoir Cryogenics piping

5 cavities 1 solenoid

LHe reservoir :-250 l capacity-Ø 0.35m, t=4mm-316L electro-polished-Lower flanges location within 1 mm

Supporting frame :-2.1m x 0.4m x 0.4m

-316L, electro-polished-130 kg welded assembly

-Piping : LHe 4.5K, 4.5 bara

Thermal Shield :-2.2m x 1.8m x 0.9m

-300 kg bolted assembly-2 mm thick Cu Ni-plated

-Piping : GHe 70K, 13 bara-No porosities after brazing

Vacuum vessel:-15 mm (40mm) thick plates-316L polished-4.5 T welded assembly

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HIE-ISOLDE: Model checks

Finite Element Model (source ESA/ECSS standards):

Geometry Mesh Loads Rigid body motion

7

Thermal steady-state analysis

OB: Radiative heat transfer between the Vacuum Vessel and the Thermal Shield Emissivity

Vacuum vessel: 0.2 Thermal shield: [0.033,0.066]

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.1150

100

150

200

250

300

350

400

450

500

emissivity of TS

Hea

t loa

d to

TS

[W]

Two thermalisations

One thermalisation

Only conduction 50 h 65 hConduction + radiation 21 h 23 h

About 1st part1

2

3

4

8

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

9

Supporting frame

Ob: temperature mapping during the cooling down

Hp: 1. Isolated system;2. Perfect contact between the parts;

Loads: Conduction; Forced convection in the cooling circuit @4.5K; Radiation to the TS@70K;

Materials: Frame: stainless steel 316L Thermalisations: copper

10

Supporting frame

Hp: isolated system

Cooling phase 2: TS@70K CM warm

Tin=300K

Boundary conditions: T(A)=300K T(B)=T(C)=70K Rad on the panel

0 10 20 30 40 50 60 70 80 90 100275

280

285

290

295

300

time [h]

tem

pera

ture

[K]

probe n.1

without radiationwith radiation

0 10 20 30 40 50 60 70 80 90 100100

120

140

160

180

200

220

240

260

280

300

time [h]

tem

pera

ture

[K]

probe n.2

without radiationwith radiation

0 10 20 30 40 50 60 70 80 90 10080

100

120

140

160

180

200

220

240

260

280

300probe n.4

time [h]

tem

pera

ture

[K]

without radiationwith radiation

0 10 20 30 40 50 60 70 80 90 10050

100

150

200

250

300

time [h]

tem

pera

ture

[K]

probe n.3

without radiationwith radiation

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Frame

Heat flux in the stainless steel tube

0 1 2 3 4 5 6 7 8 9 10

50

100

150

200

250

300temperature probe n.1

time [h]

tem

pera

ture

[K]

continuous contactwelded contacts

0 1 2 3 4 5 6 7 8 9 10

50

100

150

200

250

300temperature probe n.3

time [h]

tem

pera

ture

[K]

continuous contactwelded contacts

0 200 400 600 800 1000 1200 1400 1600 1800 2000

20

40

60

80

100

120

140

160

180

200Temperature distribution with welded contacts

length [mm]

tem

pera

ture

[K]

1h3h6h9h

Hp: isolated system

Cooling phase 3-4: TS@70K Frame 300K to 4.5K

Boundary conditions: Forced convection:

continuous contact vs. welded contact Constant h vs. variable h(x)

Radiation TS@70K

12

Frame

Fully developed turbulent flow Hp: isolated system

Cooling phase 3-4: TS@70K Frame 300K to 4.5K

Boundary conditions: Forced convection:

continuous contact vs. welded contact Constant heat flux vs. variable

Radiation TS@70K

0 200 400 600 800 1000 1200 1400 1600 1800 2000

50

100

150

200

250Temperature distribution

length [mm]

tem

pera

ture

[K]

1h3h6h9h

13

Frame

0 200 400 600 800 1000 1200 1400 1600 1800 2000

20

40

60

80

100

120

140

160

180

200Temperature distribution with welded contacts and radiation

length [mm]

tem

pera

ture

[K]

1h1h rad3h3h rad6h6h rad9h9h rad

Hp: isolated system

Cooling phase 3: TS@70K Frame 300K to 4.5K

Boundary conditions: Forced convection Radiation TS@70K

0 1 2 3 4 5 6 7 8 9 10

50

100

150

200

250

300temperature probe n.1

time [h]

tem

pera

ture

[K]

welded contactswelded and radiation

0 1 2 3 4 5 6 7 8 9 10

50

100

150

200

250

300temperature probe n.4

time [h]

tem

pera

ture

[K]

welded contactswelded and radiation

14

Supporting frame

Hp: isolated system

Cooling phase 3-4: TS@70K Frame 300K to 4.5K

Boundary conditions: Forced convection Radiation TS@70K

About 1st part1

2

3

4

15

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

16

Omega Plate

Ob: determination of the displacement of the targets

Hp: 1. Isolated system;2. Perfect contact between the parts;

Loads: Conduction 4.5K on thermalisation;

Materials: Frame: stainless steel 316L Thermalisation: copper Targets: titanium

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Omega Plates

About 1st part1

2

3

4

18

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

19

Vacuum vessel cleaning (1/2)

Ob: Stress analysis/buckling verification of the bottom beams of the vacuum vessel for cleaning;

Hp: 1. Isolated system;2. Perfect contact between the parts;

Loads: Gravity; Fluid:

density ρ=2ρH2O=2000 kg/m3 ; volume V=4 m3;

Materials: Stainless steel 316L

The bottom plate of the vacuum vessel is affected by a max totaldeformation of 0.64 mm under the mentioned load condition. Themaximum von Mises stress on the bottom plate is 60MPa, 2.8 timesbelow the yield strength.

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Vacuum vessel cleaning (2/2)

The linear bucking analysis shows a load multiplier (buckling factor of safetyfor the applied load) of 125.46 on the first mode

In the large deformation analysis, a total load of 500,000N (conservative assumption) isapplied in 4 steps together with an additional lateral force of 500N in order to createinstability.The section shows stress over 130MPa around 60,000N (in line with the results from theelastic analysis). After this limit the plastic region starts to spread all around the beam evenif any bucking phenomenon is still not involved.

About 1st part1

2

3

4

21

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

RF cable

Top of the cryostat

41.5

Elbow N connectors

≈ 2000

coupler

Thermal shield

41 ≈ 150

Ob: temperature mapping of the RF cable

Hp: 1. Isolated system2. Perfect contact between the parts;

Loads: Conduction; Power generation: Joule effect; Radiation to ambient;

Materials: stainless steel 316L Thermalisations: copper

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Part Material

Core copper

Dielectric Foamed polyethylene

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RF cable

0 100 200 300 400 500 600 700 800 900 1000

69.5

70

70.5

71

length [mm]

tem

pera

ture

[K]

Temperature along the tube

300-70300-70-rad70300-70-rad70-4.5300-70-rad70-4.5-rad70

0 500 1000 1500 2000

50

100

150

200

250

300Temperature along the RF cable

length [mm]

tem

pera

ture

[K]

300-70300-70-rad70300-70-rad70-4.5300-70-rad70-4.5-rad70

0 500 1000 1500 2000

50

100

150

200

250

300

length [mm]

tem

pera

ture

[K]

Temperature along the RF cable

q = 0.5Wq = 5W

About 1st part1

2

3

4

24

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

25

Solenoid Splice

Insulator

Insulator

316L316L Insulator

Bus bar

Solenoid lead

Parameters :

R < 10 nΩ Dynamic heat dissipation < 1mW 120A nominal Self protected

Ob: determination of the thermal transient behaviour of the TS

Hp: 1. Isolated system;2. Perfect contact between the parts;

Loads: Heat generation for joule effect; Forced convection @4.5K;

Materials: Stainless steel 316L Copper RRR100

26

Solenoid Splice

About 1st part1

2

3

4

27

Outline

Omega plates

Supporting frame

Vacuum vessel cleaning

5

6

7

Solenoid splice

RF cable

Conclusions and next steps

28

Conclusions

Thermal network; General analytical estimation of heat loads inside the cryomodule –

updated version; FEM model – validated with the ECSS standards; Global thermal steady state analysis; Transient steady state analysis; Advanced analysis on some cases;

Next steps:

Limits for cryogenic mass flow Alignment Current leads Instrumentation

29

References

[1] S. Kasap, Essential Heat Transfer for Electrical Engineers: Second Edition, 2003.[2] Y. Leclercq, “Heat load estimation for the HIE-ISOLDE cryomodule,” CERN, 2013-03-12.[3] N. Delruelle and Y. Leclercq, “Cryogenic procedures, layout and operation of the HIE-ISOLDE cryomodule,” CERN, 2013-07-01.[4] D. Ramos, “Radiation heat exchange in the HIE-ISOLDE cryomodule,” CERN, 2013-08-01.[5] L. Williams, “Cryostat for HIE-ISOLDE high energy cryomodule,” CERN, 2010-06-17.