IT & D1 HeII cooling-variants WP3 Meeting (24th of April 2013) IT & D1 HeII cooling-variants R. van Weelderen (CERN)

Overview Variants for placing cryo-equipment considered Actively cooled parts: ∆T, HX-size as function of total heat load Passively cooled parts: Conduction area as function of heat load per meter Summary of requirements as function of HeII- cooling-variant

Variants for placing cryo-equipment considered (1 of 4) actively cooled passively cooled Phase-separator & Piping entries/exits Phase-separator & Piping entries/exits Possible QRL-jumper SM & QRL-jumper Q1,Q2a,Q2b,Q3: actively cooled for about 41 m, double-HXs (80 mm Ø holes) needed CP & D1 : passively cooled for about 16 m, no HXs needed

Variants for placing cryo-equipment considered (2 of 4) actively cooled passively cooled Phase-separator & Piping entries/exits Phase-separator & Piping entries/exits Possible QRL-jumper SM & QRL-jumper Q1,Q2a,Q2b,Q3+CP: actively cooled for about 49 m, double-HXs (80 mm Ø holes) needed D1 : passively cooled for about 8 m, no HXs needed

Variants for placing cryo-equipment considered (3 of 4) actively cooled passively cooled actively cooled Phase-separator & Piping entries/exits Phase-separator & Piping entries/exits Possible QRL-jumper SM & QRL-jumper Phase-separator Piping entries/exits Q1,Q2a,Q2b,Q3: actively cooled for about 41 m, double-HXs needed CP : passively cooled for about 8 m, no HXs needed D1 : actively cooled for about 8 m, double-HXs needed

Variants for placing cryo-equipment considered (4 of 4) actively cooled actively cooled Phase-separator & Piping entries/exits Phase-separator & Piping entries/exits Possible QRL-jumper SM & QRL-jumper Phase-separator Piping entries/exits Q1,Q2a,Q2b,Q3: actively cooled for about 41 m, double-HXs needed CP,D1 : actively cooled for about 16 m, double-HXs needed

Actively cooled IT-parts Total power extraction limited by : # (2) size (80 mm holes) of the HXs For both variants 1 & 2, we can extract the total IT-CP-D1 heat up to a maximum of 550 W with a ∆T < 100 mK.

Passively cooled parts Variant 1: D1+CP conduction area > 300 cm2 Variant 2: D1 conduction area > 130 cm2 Variant 3,4: CP conduction area > ~ 100 cm2 (t.b.c)

Variant 3 and 4 HX comparison Give the saturation temperature at 1.800 the T of the D1 and CP helium bath is dominated by the available HX-Area and Kapitza resistance of the Cu- surfaces: 2xHXs holes Variant 3 Variant 4 49 mm - 1.925 K 54 mm 1.910 K 59 mm 1.900 K 64 mm 1.889 K 69 mm 1.963 K 1.882 K 74 mm 1.950 K < 1.880 K 79 mm 1.940 K ‘-’ : means HX overflowing and/or T > 2.0 K, non feasible configuration Variant 3, with HX-holes > 69 mm is critically dependent on the HX-area and variations in Kapitza resistance of the Cu surfaces risky configuration Variant 4, with HX-holes penetrating D1 and CP is more robust and can do with HX holes down to 49 mm

Variant 1 Variant 2 Variant 3/4 Power limit (with max HX holes of 80 mm) 550 W (Q1-D1) vapour velocity constraint 550 W (Q1-Q3) + ~ 160 W (CP-D1) = 710W Area constraint Q1-Q3 HXs Q1-Q3 Free Area Q1-Q3 Cryostat Pumping line 2x80 mm holes ~ 150 cm2 97-100 mm CP HXs CP Free Area CP Cryostat Pumping line none > 300 cm2 None or > 2x49-80 mm holes ~ 100 cm2 D1 HXs D1 Free Area D1 Cryostat Pumping line ~ 130 cm2 > 2x49-80 mm holes ~ X mm Phase separator & piping entries/exits Q1-end Q3-CP CP-D1 CP-D1 or Q3-CP QRL-jumpers SM

Summary If Qtotal < 550 W: Variant 2 if 80 mm holes in CP allowed, if not Variant 3/4 If 550 W < Qtotal < 710 W: Variant 3/4, T-D1 will approach 2.0 K, if possible at least 2x49 (preferably 80 mm) mm holes through D1 and CP Qtotal > ~710 W becomes difficult!