Cooling Update (25 February 2014)
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Transcript of Cooling Update (25 February 2014)
The HiLumi LHC Design Study (a sub-system of HL-LHC) is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
Cooling Update(25 February 2014)
Rob van Weelderen, Cryogenic Group, Technology Department, CERN
Overview• Heat Loads + Explicit Design Margins
• IT - Bayonet Heat Exchangers
Update of Update at next video meeting!
Placing of cryo-equipment considered (variant 4)
• Phase-separator &• Piping entries/exits
• Phase-separator &• Piping entries/exits• QRL-jumper
• SM &• QRL-jumper• Phase-
separator• Piping
entries/exits
actively cooled
Q1,Q2a,Q2b,Q3: actively cooled for about 41 m, double-HXs neededCP,D1 : actively cooled for about 16 m, double-HXs needed
actively cooled
D1 & IT: heat loads
Courtesy L. S. ESPOSITO
Heat Loads: secondairies (W) 10 cm gap in ICs 10 cm gap in ICs2 50 cm gap in ICs 50 cm gap in ICs3
Magnet cold mass Beam screen Magnet cold mass Beam screen
Q1A + Q1B 100 175 100 170
Q2A + orbit corr. 95 60 100 65
Q2B + orbit corr. 115 80 120 80
Q3A + Q3B 140 80 140 80
CP 55 55 60 55
D1 90 60 90 60
Interconnects 20 140 20 105
Total 615 650 630 615
However these loads have to be corrected for the expected 10 % transparency of the Tungsten absorbers material with respect to the Pure Tungsten used for the Fluka calculations
+ additional loads -
D1 & IT: heat loadsCorrected for 10 % tungsten transparancyHeat Loads: secondairies (W) 10 cm gap in ICs 10 cm gap in ICs2 50 cm gap in ICs 50 cm gap in ICs3
Magnet cold mass Beam screen Magnet cold mass Beam screenQ1A + Q1B 117.5 157.5 117 153Q2A + orbit corr. 101 54 106.5 58.5Q2B + orbit corr. 123 72 128 72Q3A + Q3B 148 72 148 72CP 60.5 49.5 65.5 49.5D1 96 54 96 54Interconnects 34 126 30.5 94.5beam-screen contact load 28 28 28 28static heat load 28 28 28 28cryostat ends 16 16 16 16electron cloud 0 0 0 0image currents ? ? ? ?Total 753 658 764 626
beam-screen contact load 0.5W/mstatic heat load 0.5W/mcryostat ends 16Welectron cloud 0Wimage currents ?W
Q1-Q2A ~ 260 W, Q2B-Q1B ~ 310 W, D1+CP ~ 195 W,Beam screens ~ 785 W
Assuming no electron cloud we have already IT+D1: 764 WAssuming image currents 0.5 W/m on BS (tbc) : 655 W
What will be our design choice?
Propose + 20 % margin ~ 920 W (686 @IT) at 1.9 K,785 W at BS
Targeting 686 W means:
HX inner diameter ~78 mm, Yoke hole ~88 mm
Targeting 686 W with split pumping option means:
HX inner diameter ~57 mm, Yoke hole ~65 mm
Notes:• At 800 W on the Q1-Q3B the split option starts
to break down due to vanishing T-regulation margin (but can still “work”)
• D1 can extract ~250 W with 2x49mm ID HX’s (2x58mm Yoke holes): about 350-400 W with 2x68 ID HX’s (2x77mm Yoke holes).
• Total IT+CP+D1 heat extraction capacity using split pumping option 1050 W – 1200 W