1 / 26

ITS Ultr a-low-Mass Cooling System Pipe Design: Minimum Inner D iameter calculation &

ITS Ultr a-low-Mass Cooling System Pipe Design: Minimum Inner D iameter calculation & Constructive Considerations. Enrico DA RIVA Manuel GOMEZ MARZOA CFD Meeting - 25 th January 2013. Contents. Overview Cooling system: constraints Cooling concepts Pipes per stave

kamin
Download Presentation

ITS Ultr a-low-Mass Cooling System Pipe Design: Minimum Inner D iameter calculation &

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ITS Ultra-low-Mass Cooling System Pipe Design: Minimum Inner Diameter calculation & Constructive Considerations Enrico DA RIVA Manuel GOMEZ MARZOA CFD Meeting - 25th January 2013 CFD Meeting - 25th January 2013

  2. Contents • Overview • Cooling system: constraints • Cooling concepts • Pipes per stave • Operating pressure • Pipe Inner Diameter optimization • Inner Barrel layers • Outer Barrel layers • Construction of the tubing • Material • Erosion constraints • U-pipe construction CFD Meeting - 25th January 2013

  3. Overview Inner Barrel Outer Barrel x/X0 < 0.3% per layer x/X0 < 0.8% per layer Wound-truss structure. Concept for outer layers (4-5, 6-7), based on the high-conductivity plate cooling idea. Wound-truss structure with high-conductivity plate. CFD Meeting - 25th January 2013

  4. Cooling system: constraints • Refrigerant maximum velocity: • Avoiding failure by erosion. • Minimizing pressure drop. • No specific recommendations found for such small plastic pipe: • ASHRAE Handbook: not exceeding 1.5 m s-1 would minimize effects of erosion. • Catheters use similar pipes and materials. • 8.5 French gauge catheter (2.8 mm OD, ~1.5 mm ID) cordis/introducer 1. • Max. flow rate: 126 mL min-1 = 7.56 L h-1 = 1.18 m s-1 • Max. flow rate w/ p. bag @300 mmHg: 333 mL min-1=19.98L h-1 = 3.1 m s-1 • Damage by erosion in a plastic pipe could be roughly estimated by assessing the material hardness and compared to that of a regular copper pipe (but degradation?). • Admissible pressure drop: • Single-phase cooling: depends on the cooling system design. • Two-phase cooling: must be kept low to ensure the minimum ΔTSatacross stave. • Admissible ΔTRefrigerant across stave: • Related to stave temperature uniformity. • In a two-phase cooling system, should not decrease a lot (risk of going below dew point). 1Source: http://emupdates.com/2009/11/25/flow-rates-of-various-vascular-catheters/ CFD Meeting - 25th January 2013

  5. Where are we? Inner Barrel • Successful proposal (up to 0.5 W cm-2) • Several prototypes for test: • Pipe ID = 1 mm • Squeezed pipes • K1100 Plate (λ ~ 1000 W m-1 K-1) No prototype performed OK (0.3 W cm-2) A last prototype with larger winding angle will be available for test CFD Meeting - 25th January 2013

  6. Where are we? Inner Barrel • Pipe dimensions: • Initially: ID = 1.450, OD = 1.514 mm • Reason: winding CF around pipe without breaking it (wound-truss structure). • Used as well for the wound-truss structure with high conductivity plate. • Pipe ID could be reduced from the refrigerant viewpoint (water/C4F10). • Constructively possible in High-conductivity plate prototype! • Reduced pipe ID prototype: ID = 1.024, OD = 1.074mm: TO BE TESTED!! • Pipe ID optimization: consider: • Different cooling system layouts. • Refrigerants. • Pipe erosion. • Pipe material: • So far: only polyimide (Kaption®) has been taken into consideration and used for the construction of prototypes. • Concerns: • Pipe integrity? • Mechanical stiffness? (in case of making the U-bend without connectors). • … CFD Meeting - 25th January 2013

  7. Cooling Concepts Inner Barrel Pipes per stave • 1 straight pipe along each stave: T1 T2 Stave ΔTRef-Stave = T3-T1 Stave T3 • U-pipe along each stave: T1 T2 = T1+0.5*ΔT Stave ΔTRef-Stave = T3-T1 T3 CFD Meeting - 25th January 2013

  8. Cooling Concepts Inner Barrel Operating pressure • Water in single-phase flow: • Leak-less mode (p<1 bar):Δp at stave must be kept low! • No connectors:pMax and Δp limited by pipe strength. • C4F10in two-phase: • Main limitation is ensuring ΔTSat < ΔTSat-Admissibleacross the stave. Current design options • 6 possible designs. • 4 with water • 2 with C4F10 Water in single-phase orC4F10 two-phase. Leak-less or no connectors. Single pipe or U-pipe per stave. • Goal: assess the minimum pipe diameter for each of these designs. • Assuming reasonable operating conditions and respecting constraints. • Comparing with experimental results. CFD Meeting - 25th January 2013

  9. Pipe Inner Diameter Optimization • Restrictions: • Single/U-pipe: • ΔTWater= 3-6 K • Lpipe= 0.29-0.58 m • Leak-less/no connectors: • ΔpMax-InOut= 0.2-2 bar Inner Barrel Water in single-phase • Assumptions: • Stave power density: 0.4 W cm-2 • Water maximum velocity: 1.5 m s-1 1,2. Water, single pipe: Water, U-pipe, leak-less: Water, U-pipe, no connectors: CFD Meeting - 25th January 2013

  10. Pipe Inner Diameter Optimization Inner Barrel C4F10 in two-phase • Restrictions: • Single/U-pipe: • ΔTMax-InOut= 3-6 K • ΔpMax-InOut= 0.19-0.37 bar • Lpipe= 0.29-0.58 m • Assumptions: • Stave power density = 0.4 W cm-2 • ΔxInOut= 0.5 (conservative) • xAverage = 0.5 (for Friedel corr.) C4F10, single pipe: C4F10, U-pipe: CFD Meeting - 25th January 2013

  11. Pipe Inner Diameter Optimization Inner Barrel SUMMARY • Restrictions: • ΔTMax-InOut= 3-6 K • Lpipe= 0.29-0.58 m • Assumptions: • Stave power density: 0.4 W cm-2 • The minimum pipe diameter is achieved for design number 4: • ID=0.55 mm ~ 62% smaller than current 1.45 mm ID! • Refrigerant material budget (i.e. water) is 7 times lower! CFD Meeting - 25th January 2013

  12. Where are we? Outer Barrel Spaceframe Kapton, ID=2.794 mm wall= 0.06mm Carbonprepregthick=TBD CF Plate Carbonprepregthick=TBD Si 0.05mm thick Bus 30.4 mm CFD Meeting - 25th January 2013

  13. Cooling Concepts Outer Barrel Pipes per stave • 1 straight pipe along each half stave: T1 T2 Half-stave ΔTRef-Stave = T3-T1 Half-stave T3 Stave • U-pipe along each half-stave: T1 Half-stave T2 = T1+0.5*ΔT T3 ΔTRef-Half-Stave = T3-T1 Half-stave CFD Meeting - 25th January 2013

  14. Cooling Concepts Outer Barrel Operating pressure • Water in single-phase flow: • Leak-less mode (p<1 bar):Δp at stave must be kept low! • No connectors:pMax and Δp limited by pipe strength. • C4F10in two-phase: • Main limitation is ensuring ΔTSat < ΔTSat-Admissibleacross the stave. Current design options • 6 possible designs. • 4 with water • 2 with C4F10 Water in single-phase orC4F10 two-phase. Leak-less or no connectors. Single pipe or U-pipe per stave. • Goal: assess the minimum pipe diameter for each of these designs. • Assuming reasonable operating conditions and respecting constraints. • Comparing with experimental results (not yet). CFD Meeting - 25th January 2013

  15. Pipe Inner Diameter Optimization • Restrictions: • Single/U-pipe: • ΔTWater= 3-6 K • Lpipe= 0.85-1.70 m • Leak-less/no connectors: • ΔpMax-InOut= 0.2-2 bar Outer Barrel Water in single-phase • Assumptions: • Stave power density: 0.4 W cm-2 • Water maximum velocity: 1.5 m s-1 L4-5 1,2. Water, single pipe per half stave: Water, U-pipe per half stave, leak-less: Water, U-pipe per half stave, no connectors: CFD Meeting - 25th January 2013

  16. Pipe Inner Diameter Optimization Outer Barrel C4F10 in two-phase L4-5 • Restrictions: • Single/U-pipe: • ΔTMax-InOut= 3-6 K • ΔpMax-InOut= 0.19-0.37 bar • Lpipe= 0.85-1.70 m • Assumptions: • Stave power density = 0.4 W cm-2 • ΔxInOut= 0.5 (conservative) • xAverage = 0.5 (for Friedel corr.) C4F10, single pipe per half stave: C4F10, U-pipe per half stave: CFD Meeting - 25th January 2013

  17. Pipe Inner Diameter Optimization Outer Barrel SUMMARY • Restrictions: • ΔTMax-InOut= 3-6 K • Lpipe= 0.85-1.70 m • Assumptions: • Stave power density: 0.4 W cm-2 L4-5 • The minimum pipe diameter is achieved for design number 4: • ID=1.71 mm ~ 39% smaller than the ordered 2.794 mm ID. CFD Meeting - 25th January 2013

  18. Pipe Inner Diameter Optimization • Restrictions: • Single/U-pipe: • ΔTWater= 3-6 K • Lpipe= 1.5-3.0 m • Leak-less/no connectors: • ΔpMax-InOut= 0.2-2 bar Outer Barrel Water in single-phase • Assumptions: • Stave power density: 0.4 W cm-2 • Water maximum velocity: 1.5 m s-1 L6-7 1,2. Water, single pipe per half stave: Water, U-pipe per half stave, leak-less: Water, U-pipe per half stave, no connectors: CFD Meeting - 25th January 2013

  19. Pipe Inner Diameter Optimization Outer Barrel C4F10 in two-phase L6-7 • Restrictions: • Single/U-pipe: • ΔTMax-InOut= 3-6 K • ΔpMax-InOut= 0.19-0.37 bar • Lpipe= 1.50-3.00 m • Assumptions: • Stave power density = 0.4 W cm-2 • ΔxInOut= 0.5 (conservative) • xAverage = 0.5 (for Friedel corr.) C4F10, single pipe per half stave: C4F10, U-pipe per half stave: CFD Meeting - 25th January 2013

  20. Pipe Inner Diameter Optimization Outer Barrel SUMMARY • Restrictions: • ΔTMax-InOut= 3-6 K • Lpipe= 1.50-3.00 m • Assumptions: • Stave power density: 0.4 W cm-2 L6-7 • The minimum pipe diameter is achieved for design number 4: • ID=2.99 mm ~ 6.5% bigger than the ordered 2.794 mm ID. CFD Meeting - 25th January 2013

  21. Pipe Inner Diameter Optimization 0.4 W cm-2 SUMMARY MAT. BUDGET CONSIDERATIONS • Achieving the target of 0.3%: • Use a two-phase flow. • Minimize pipe diameter to reduce the impact of the refrigerant to the global material budget. • BUT need to keep thermal contact between Si and pipe! • Constructive issues when ↓ID CFD Meeting - 25th January 2013

  22. Construction of the tubing • General considerations: • Robust: elastic modulus, high burst pressure. • Thin walls:reduce mat. budget. • Compatible with refrigerant(C4F10). • Easy to bend:in case of making a no-connector stave, limited space. • Erosion:related to the material hardness. • Specific requirements: • High radiation hardness:minimum damage. • Ageing:physical and chemical stability over time. • Comply to LHC Fire Safety Instruction (IS-41) • Low material budget material (plastics better than metals). CFD Meeting - 25th January 2013

  23. Construction of the tubing • General considerations: • Robust: • Tensile strength = 117.9 Mpa • Flexural Modulus = 4.1 GPa • Thin walls:down to 0.025 mm for a pipe with 0.55 mm ID • Compatible with refrigerant(C4F10): yes • Easy to bend: • Must avoid kinking failure: when section deforms to an elliptical shape. • A reinforcement braid can be included locally to prevent kinking. • Braid: SS or others, Covered with Nylon, Pebax… • Flexible liners like Nitinol (Ni + Ti) or Kevlar could reinforce the tube to be bent and preserve the shape (shape memory). • Erosion:related to the material hardness. • Polyimide/PEEK: 87D (Shore D) • PVC Pipe: 89D (Shore D) • Copper: 372 Mpa (Vickers) Minimum bend radius? In Vickers, polyimide would have 772 MPa CFD Meeting - 25th January 2013

  24. Construction of the tubing • Specific requirements: • High radiation hardness:according to CERN-98-01 report, polymide: • No problem below 107Gy • Mild damage between 107 to5 107Gy • 1st layer of ITS Inner Barrel will be exposed to 700 krad/yr.=7000 Gy/yr. • Ageing:physical and chemical stability over time. • Plastic Pipe Institute states corrosion is not an issue in plastic pipes. • Comply to LHC Fire Safety Instruction (IS-41) • Polyimide is allowed. • Nylon® (polyamide) is allowed if a fire retardant NOT containing halogen, sulphuror phosphorus. • Pebax: polyether block amides – “legal” in cavern?? • Low material budget material (plastics better than metals). • Polyimide: X0 = 29 cm, minimum wall thickness is 0.025 mm. • PEEK: X0 = 31.45 cm, minimum wall thickness is 0.25 mm. CFD Meeting - 25th January 2013

  25. Construction of the tubing • Advantages of a PEEK pipe over polyimide: • Low material budget material. • Polyimide: X0 = 29 cm • PEEK: X0 = 31.45 cm • The U-turn can be shaped and retain the shape. • Extremely stable. • More common in scientific applications than polyimide tubing. • Advantages of a polyimide pipe over PEEK: • Higher radiation hardness:according to CERN-98-01report. • Wall thickness: • Polyimide minimum wall thickness = 0.025 mm. • PEEK minimum wall thickness = 0.25 mm CFD Meeting - 25th January 2013

  26. ITS Ultra-low-Mass Cooling System Pipe Design: Minimum Inner Diameter calculation & Constructive Considerations Enrico DA RIVA Manuel GOMEZ MARZOA CFD Meeting - 25th January 2013 CFD Meeting - 25th January 2013

More Related