1. Local Supports for Inclined Layout: CERN Update
D. Alvarez Feito
CERN EP-DT-EO
CERN, November 2016
04/11/2016

2. Local Support Designs for Inclined Layouts
Stave/Longeron Approach
Conservative approach (two pipes per module)
Intermediate approach (single pipe per module, soldered interfaces)
Aggressive approach (single pipe, glued interfaces)
Tilted Rings (e.g. CMS)

3. Aggressive approach: Curly Pipe Design
Design solution developed for SLIM v3.0
Compatible with common inclined effort (“Aggressive Version”)
Main Objectives:
Radical reduction of the cell mass while meeting TFM requirements
Eliminate the need for solder interfaces
Minimise the effect of the Ti pipe on the positioning of the modules (e.g. introduce local CFRP supports)
Minimise ΔT within the module
Facilitate module loading in “flat” configuration
Allow for re-workability/replacement of defective modules (i.e. modularity).

4. Inclined Section: Principle (I)
Thermal Management
Curly Pipe (i.e. smooth 3D loops in the cooling line)
Increase usable pipe surface
Reduce distance from pipe to sensor
Introduce flexibility in pipe
Independent of “tilt” angle
Cooling plate
“Machined” graphite plate
Flat TPG (reinforced if needed)
Loading on flat surface
Local CFRP support for positioning and stability
DOES NOT PLAY ANY THERMAL ROLE (thus, not included in thermal FEA)
Support two adjacent tilted modules (minimise #parts, increase stiffness)
Define positioning of cooling plate (locator system, e.g. pins, ruby balls)
Constrain the pipe (epoxy glue, not conductive)

5. Inclined Section: Principle (II)
Module Cell
(Module + cooling plate)
Support Structure
(Longeron + Tilted Support + Curly Pipe)
Cooling Plate
(TPG, graphite)
Silicon Sensor
(Includes machined holes/locators)
Conductive glue
Loop Pipe
(glued to support/longeron)
CFRP Support
(glued to longeron)
CFRP support includes locators for module cell
(pins, ruby spheres)
Longeron

6. Inclined Section: Principle (III)
Final Assembly
(Support Structure + Module Cell)
Gap Filler/TIM
(Thermal contact between pipe & plate)
Removable glue for positioning
(e.g. SE4445, no thermal role)
Module Cell
(Cooling plate + Sensor assembly)
Module cell fixed to support structure:
Gap filler/TIM for thermal contact
Removable glue (e.g. SE4445) for securing positioning /pressure (NO THERMAL ROLE)
Matching locator system between cooling plate and CFRP local support

7. Inclined Section: Thermal Performance
Graphite plate (porous or iso-graphite)
Example: Porous graphite plate (ρ=1000kg/m3, K=86Wm-1K-1, 0.36g)
Flat TPG plate (see next slides)
No machining required
High in-plane thermal conductivity → Lower ΔT within the module
Global TFM (˚C∙cm2∙W-1)
Module ΔT~7˚C

8. Thermal Performance: TPG Cooling Plate
FEA Assumptions:
Module size: 40 x 19 x 0.35 mm
TPG Size: 38x19 mm (thickness between mm)
Heat flux: 0.7W/cm2
HTC inside the pipe: 8000 W∙m-2∙˚C-1
Thickness of Gap filler/TIM between pipe and TPG plate: 0.25mm
No environmental convection/radiation
No thermal contact losses
No contribution from local support or additional CFRP reinforcement
Material properties: Ti
(Pipe)
TPG-to-Pipe Interface
(Gap Filler/Phase Change TIM)
TPG
Loaded Glue
(Sensor Interface material)
Silicon (Sensor)
Density (kg/m3)
4620
3400
2260
1200
2330
K (W/mK)
16.4 5
1500 (//)
10 (┴) 1
124

9. Thermal Performance: TPG Cooling Plate
Full contact with the pipe loop:
Global TFM (˚C∙cm2∙W-1)
TPG 0.3mm thick

10. Thermal Performance: TPG Cooling Plate
Partial contact with the pipe loop:
Section of the gap filler removed to reduce ΔT within the module α

11. Thermal Performance: TPG Cooling Plate
Partial contact with the pipe loop:
Section of the gap filler removed to reduce ΔT within the module α

12. Local CFRP Support Glued to truss
Incorporate groove to position and glue the pipe (“buried” pipe)
Incorporates locator system (e.g.pins,ruby balls) to position module cell
Ideally, it would support two tilted modules from adjacent rows
Ongoing design optimisation (geometry, layup, longeron compatibility)
Prototyping to follow (3D printed mould)
Not realistic geometry
(shown only for illustration purposes)

13. Local CFRP Support Glued to truss
Incorporate groove to position and glue the pipe (“buried” pipe)
Incorporates locator system (e.g.pins,ruby balls) to position module cell
Ideally, it would support two tilted modules from adjacent rows
Ongoing design optimisation (geometry, layup, longeron compatibility)
Prototyping to follow (3D printed mould)
Not realistic geometry
(shown only for illustration purposes)

14. Local CFRP Support Open design + stiffening rib
Tubular design (N.Geffroy)
(shown only for illustration purposes)
Not realistic geometry

15. Flat Section: Principle (I)
Thermal Management:
Single, straight pipe
Cooling TPG Plate (machined with longitudinal groove)
“Machined” TPG plate (reinforced if needed with thin CFRP plies)
Thermal contact with pipe via removable interface (gap filler /TIM)
NO soldered interface
Loading on flat surface
Local carbon support for positioning and stability
DOES NOT PLAY ANY THERMAL ROLE (thus, not included in thermal FEA)
Support two adjacent flat modules (minimise #parts, increase stiffness)
Define positioning of cooling plate (locator system, e.g. pins, ruby balls)
Constrain the pipe (epoxy glue, not conductive)
CFRP “Ribbon” or “Graphite Block”

16. Flat Section: Principle (II)
Module Cell
(Module + cooling plate)
Module
Machined TPG
Support Structure
(Longeron + Tilted Support + Pipe)
Conductive glue (TIM)
CFRP Supports
(glued to longeron)
Ti Pipe
(glued to CFRP supports)

17. Flat Section: Principle (II)
Gap filler/Phase Change TIM
(thermal contact Ti-TPG)
Removable glue for fixation
(e.g. SE4445, no thermal role)
Module Cell
(positioning via locator system in supports/cold plate)

18. Thermal Performance: TPG Cooling Plate
Example (0.4mm thick plate):
Global TFM (˚C∙cm2∙W-1)
Module ΔT (˚C)

19. Thermal Performance: TPG Cooling Plate
TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module.
Parametric study
Module Size (W,L): 38x40mm

20. Thermal Performance: TPG Cooling Plate
TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module.
Parametric study
Module Size (W,L): 38x40mm

21. Thermal Performance: TPG Cooling Plate
TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module.
Parametric study
Module Size (W,L): 38x40mm

22. Thermal Performance: TPG Cooling Plate
TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module.
Parametric study
Module Size (W,L): 38x40mm

23. Prototyping Activities

24. ‘Curly’ Pipe: Initial Thermal Tests
Very preliminary thermal tests (stainless steel pipes)
Comparison between straight pipe and line with loops (same length)
Homogenously distributed heat load using pipe resistivity (50W)
CO2 inlet temperature set to -20°C
N. DIXON
-15.1°C
-15.3°C
-15.4°C
-16.0°C
-14.8°C

25. ‘Curly’ Pipe: Latest Thermal Tests
Assess performance of the ‘curly’ pipe for different phi positions and identify potential problems
Stainless steel pipe with 5 loops and simplified module cells:
Al cooling plate with machined groove (gap filler + clamp)
Kapton heater
NTC at the furthest corner
N. DIXON; R. GOMEZ
See for the results

26. Curly Pipe: New Prototypes
4 new prototypes produced by external company (stainless steel, OD4mm/ID2mm)
Modified geometry proposed by the company to ease manufacture
Plan:
Assess new geometry from the fluidic standpoint (i.e. CO2 behaviour) in different Φ positions
Measure Δp to validate CO2 simulations (COBRA)
Measure HTC?
If results are positive, we will launch prototyping campaign with Ti pipes (new jigs will be required, so we should converge to a suitable pipe size beforehand!!!)

27. EP-DT Thermal Set-up: Upgrade
Monitor CO2 vapour quality

28. Support Structures: Longerons
Truss Longeron:
Four new 1m-prototypes of the truss longeron (“hybrid” construction)
Production rate: 1/day (including all preparation steps)
Shell Longeron:
In-house production of shell longeron following procedure developed at Composite Design
F. BOYER