Transcript LHC Cryogenics Status and perspectives

LHC Cryogenics
Status and perspectives
S. Claudet
on behalf of Cryogenic group
Content
• Summer to September 2008
• Present activities and shut-down constraints
• Consolidations towards availability:
–
–
–
–
Machine related hardware
Utilities
Cryogenic system
Power permit (s)
• Organisation of resources
• Summary
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First cool-down of LHC sectors
First beams around LHC
300
Simultaneous Cryo
start/maintain
Short in
connection
cryostats and
repairs
200
150
All sectors at
nominal
temperature
Open Days
Temperature [K]
250
100
50
Christmas and water
maintenance shut-down
UX85
Ph1
works
0
12Nov2007
10Dec2007
07Jan2008
04Feb2008
03Mar2008
31Mar2008
28Apr2008
26May2008
23- 21-Jul- 18Jun2008 Aug2008
2008
15Sep2008
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A RC 6 7 _M A G S _T T A V G .P O SS
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Cooling sectors + Cryo tuning + Powering activities
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LHC Cryogenics for D-day
Thanks to contributors and partners, luck was with the braves !!!
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LHC sectors: Average temperature of ARCS
10
Temperature
8
6
UX85
Ph1
works
4
Oil leak
Air
leak
Oil
filters
Transformers
1,2
3,4
Tu Air CC
24V
2
0
21280411182501081522JulJul- Aug- Aug- Aug- Aug- Sep- Sep- Sep- Sep2008 2008 2008 2008 2008 2008 2008 2008 2008 2008
LHC Beams around the ring for the 1st time !
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s1-2
s2-3
s3-4
s4-5
s5-6
s6-7
s7-8
s8-1
1.8K Units:
Global significant progress !
Sector 12 - Cold Compressor inlet
CC inlet P [Bar]
1.0E+00
Bearings/Drive
communication problems
Re-connection at lower pressures
(70-55-30mbar)
1.0E- 01
Two Months
before manual
stop !
1.0E- 02
30- 062008
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31- 072008
31- 082008
01- 102008
Better than 2wks MTBF Spring’08 !
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LHC Cryogenics Autumn’08
Repairs
Consolidations
Floating,
TTMaxMAG<130K
Maintenance
Cryo tests:
2 sectors on
one Ref.+
calorimetry
Warming-up by controled
degradation of vacuum
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Two sectors on one cryoplant
Competitive for recovery after stops
(<10hrs for CC, <24hrsLower
afterCold
power
Box
failure for 2 sectors)
Cold Compressor
box
Distribution Line
Powering tests
Magnet Cryostats
LHC Sector (3.3 km)
Warm Compressor
Station
Surface
≈ 5MW of power input,Upper
instead
Cold of
Box
8MW (2x4MW)
Warm Compressor
Station
1.8 K Refrigeration Unit
Cold Box
4.5K
Interconnection Box
15 mbar
Shaft
Cold Compressor
box
Distribution Line
Powering tests
Magnet Cryostats
LHC Sector (3.3 km)
Not valid for large transients, but an interesting feature for low beam loads,
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or validated
refrigerator
Cavern
≈ 10% capacity left for dynamic
loads,
after specific adjustments
Warm Compressor
Warm Compressor
Station
madeStation
New 4.5 K refrigerator
Tunnel
1.8 K Refrigeration Unit Ex-LEP 4.5 K Refrigerator
Preparation of LHC 1st winter shut-down
300
Temperature [K]
250
19Sept’08
Warm-up by controled
degradation of vacuum
Warm-up of 12
200
Sectors progressively emptied,
operation “75K stand-by” mode
for protection of PIM’s and
minimised thermal expansions
150
100
50
0
15-09-2008
29-09-2008
13-10-2008
27-10-2008
10-11-2008
24-11-2008
A RC 5 6 _M A G S _T T A V G .P O SS
A RC
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A RC
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A RC
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A RC 6 7 _M A G S _T T A V G .P O SS
A RC
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Magnet emptying for maintenance or warm-up for consolidations
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Helium inventory and remote storage
8 x 16 t = 128 t
12t LHe
Losses 34: 8 t
Remote: 23 t
(virtual storage)
LHC: 48 t
(3 sectors)
50
4.5
45
4
40
3.5
35
3
30
2.5
25
2
20
1.5
15
1
10
0.5
5
0
0
43
44
45
46
47
48
49
50
51
52
53
Current weeks
T ruc k load (t)
C umulated remote
3 s ec tors
T ruc k loaded
E s timation
2 s ec tors
C umulated expec ted
4 s ec tors
Only up to 5 sectors empty in 2008
(3 sectors used as storage)
Spring 2009: 25t back + 10t new
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Cumulated storage
Storage: 57 t
45t Ghe (Max/50t)
Remote storage
5
Road Trailer [t]
8t
Consolidations: Machine related
• Connection cryostats (56)
• Level gauge piping for stand-alone magnets
– On warm sectors, or
– When temporary local warming is possible, or
– On most delicate type (MQY)
• Y line for bayonet heat exchanger tubes (34-78-81)
when sector warm=> 34 only
• Superconducting link at P3 (DSLC)
• Heat sink (Cu leads) on some triplets (t.b.c)
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Levels for standalone magnets
Since summer 2008:
- Case by case compromise found
- Global pressure stability required
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For 2009: Pipe work to be consolidated
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when possible
The DFBLC and DSLC in UJ33
Not OK
OK
Cable layout
Layer 1 (inner) Wires 1-10:
Layer 2: 11-26:
Layer 3 (outer layer) 27-48:
Cryo instrumentation tuned for larger Helium mass-flow
=> Stable operation now at 9-10 g/s (w.r.t 4.5 g/s before)
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LHC MAC
24 - Cryogenics !
Improvement for powering above
expectations
Towards more stable utilities
• Electricity:
– 3.3kV input Power, 400V distribution, 24VDC units
– Spares or fall-back solutions being implemented
• Cooling water:
– Many consolidations identified and launched
– Main water pumps: MTTR ≈ Cryo tolerance …
• Controls:
– Communication cards and network being consolidated
• Insulation vacuum:
– Interlocks for “catastrophic rupture” to be simplified
– PLC’s to gauges to be put on UPS …
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Cryogenics main consolidations
• Mecanics:
– Repairs of few leaks into cold-boxes insulation vacuum
– Change of 1 control valve for 1.8K units when possible
– Change of about 100/2200 valve popets
• Instrumentation
– Instrumentation on electrical feed boxes (TT, CV)
– Tuning of valve positioner dynamics
– Correction of Non-Conformities
• Automatisms:
– 2nd generation of logic (simplified) for tunnel
– Standardisation of procedures for interconnection of sub-systems
– 1.8K units
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Power permit (s)
Often ≈ 80% availability on a sector, sometimes ≈ 90%, much more expected!
• Conditions to be reviewed and possibly relaxed
based on experience:
– Cryo maintain (slow abort) to really protect
equipment
– Cryo start (start interlock) if powering ramp could be
aborted, not to illustrate cryo stability
• Analysis to be made for sets of pre-defined
optics requirements:
– Orbit correctors, decapoles, spare current leads not
always necessary …
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Organisation of resources
•
Cool-down of 8 sectors:
– Should be OK with structure in place
LHC
Cryo OP
• HWC of many sectors in parallel:
Winter
shut – Since mid Jan’08, operators up to 22h and Saturdays
down – Since Spring’08, two shifts (week) and Saturdays (day)
•
First beams:
– We do not have CERN staff (alone) for any kind of shift
– Various type of shifts possible via our industrial partner, with CERN experts and
local control rooms (day time) in back-up
•
After July 2009:
Sept. to Nov’08: 2 x (3x8h-7d/7d) in CCC
Clearly a must at the beginning!
– End of present operation contract, with in-sourcing plus “Field Support Unit” as
reference solution, to be re-evaluated end 2008
New operators recruted (3 + 2 soon) one year before the end of
contracts of 1st generation of operators (4), allowing to organise
shift work in 2009
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No significant progress yet with collaboration with other teams
Summary
• LHC Cryogenic system has been put in operation
with success and was “ready” for D-day
• Test programs were conducted to improve our
understanding and tuning of sub-systems
• Consolidation programs Utilities-Cryo-Machine are
being implemented during this winter shut-down
• Operation with shift (1 x 5x8) to start spring’09 and
possibly a bit more, with industrial support to help
for big transients and possible others for specific
cases
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LHC MAC 24 - Cryogenics