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Interconnections. Presentation Outline. Overview of the inner triplet interconnections Q1/Q2, Q2/Q3 interconnections General view Working conditions Compensation system Stability issue Vacuum vessel closure Q3/DFBX, D1/DFBX interconnections Jumper connections Quality assurance
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Interconnections Presentation Outline • Overview of the inner triplet interconnections • Q1/Q2, Q2/Q3 interconnections • General view • Working conditions • Compensation system • Stability issue • Vacuum vessel closure • Q3/DFBX, D1/DFBX interconnections • Jumper connections • Quality assurance • Interconnection status • Conclusions C. Garion
Overview of the IT interconnections Jumpers to the QRL D1 DFBX Q3 Q2 Q1 IP • Triplets installed at points 1, 2, 5 and 8, Left and Right • 2 interconnections between magnets: Q1/Q2, Q2/Q3 • 2 interconnections between magnet and DFBX at points 2 and 8 ; 1 interconnection between magnet and DFBX at points 1 and 5 • 2 interconnections between DFBX and QRL (jumpers) C. Garion
Q1/Q2, Q2/Q3 interconnections General view Heat exchanger line (L) Cold mass/heat exchanger line (M4) Pumping line 2 (Xbt) Instrumentation line (M2) Q3 Thermal shield return line (FF) Beam line (V) Q2 Main bus bar line (M1) Beam screen line (K) 4.5 K heat intercept line (C’) Thermal shield cooling line (EE), filling line (LD) and pumping line (XB) are not visible on this photo. C. Garion
Q1/Q2, Q2/Q3 interconnections Working conditions C. Garion
Q1/Q2, Q2/Q3 interconnections Interconnection and compensation system L sleeves Fixed point XB%L XB sleeves M4 sleeve New H piece Main line connection Modified with respect to initial US design after 7-8 pressure test • Comments: • All welds and welders have been qualified (CERN/SC, CERN/TS). • Few minor modifications have been implemented w.r.t. initial design (adaptation rings) C. Garion
Q1/Q2, Q2/Q3 interconnections Interconnection and compensation system Bellows main parameters C. Garion
Q1/Q2, Q2/Q3 interconnections Stability issue - Local stability (at the component scale) C. Garion
Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability (at the IC scale) Cold mass and heat exchanger Buckling mode for Q1/Q2 Initial design Higher mode at ~60 bars C. Garion
Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability (at the IC scale) Cold mass and heat exchanger Modifications First global mode: 49.5 bars (Q1/Q2) Stiff restrain on M4 bellows • 1 mode suppressed • First mode with limited displacement • Critical pressure of ~49.5 bars for Q1/Q2 and ~49 bars for Q2/Q3 (rescaling) • Assembly of H pieces done by welded sleeves minimum of shear pres-stress in the bellows C. Garion
Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability LD bellows Interconnection support Aluminium plate Pcr ~30bars Guiding device to be installed on the end plate Pcr ~60bars Q1 EE, FF bellows Thermal shield: “Soft” boundary conditions Thermal shield extremity Pcr ~39.5bars Pcr ~50bars C. Garion
Q1/Q2, Q2/Q3 interconnections Vacuum vessel closure 4.8 mm thick Bellows buckling pressure: 3.7 bars Vacuum longitudinal force: Max 8000daN Buckling force (per rod): 5770daN Is the guide length sufficient to avoid rotation? Buckling force (per rod):1440daN Stiff guidance has probably to be implemented C. Garion
D1/DFBX, DFBX/Q3 interconnections V line Bus bar line No structural modification of original US design (except Xb fixed point Q3 IP) C. Garion
D1/DFBX, DFBX/Q3 interconnections C. Garion
D1/DFBX, DFBX/Q3 interconnections Filled weld Lip weld Butt welds with persistent ring and backing gas Butt welds with persistent ring and backing gas C. Garion
Jumper interconnections Sleeve Persistent ring Standard Arc connections except manual lip welds C. Garion
Quality assurance • Procedures for all inner triplet interconnections provided by US collaboration. • All weld process have been qualified (CERN/SC, CERN/TS and IEG/APAVE) as well as welders. • Butt welds in the interconnections are done with backing inert gas. • X-rays are carried out on all butt welds and filled welds (where possible). C. Garion
Interconnections Status Great interest to find an in-situ reparation solution C. Garion
Conclusions • Interconnection work is done according to the US procedures. • Weld process have been qualified. Welds are controlled with X-rays, where possible. • H pieces have been modified to increase stability of the cold mass lines and reliability of the heat exchanger inner copper tube. • H piece in Q2/Q3 has been validated during the pressure test in 5L up to 20 bars and with an elongation of 25mm. • Stability of interconnections could be improved to reach “standard” safety margin. C. Garion