S. Claudet - 31st May 2007 Power refrigeration for LHC
Power refrigeration Power refrigeration at 4.5K & 1.8K at 4.5K & 1.8K
for the LHCfor the LHC
S. Claudet, CERN AT-ACRS. Claudet, CERN AT-ACR
S. Claudet - 31st May 2007 Power refrigeration for LHC
ContentContent
Introduction
Required capacity and system architecture
4.5 K Refrigerators and 1.8 K Units
Recent achievements
Conclusion
S. Claudet - 31st May 2007 Power refrigeration for LHC
Long tradition and experience with cryogenics and refrigeration
LHC, the largest helium refrigeration system ever built
IntroductionIntroduction
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1960 1980 2000
Year
kW @
4.5
K
OMEGA,BEBC,
ISR Low-Beta
ALEPH,DELPHI,
LEP Low-Beta
LEP2
LHC, ATLAS, CMS
LEP2+
LH
C:
144
kW
LHC
S. Claudet - 31st May 2007 Power refrigeration for LHC
Basic choices, design criteriaBasic choices, design criteria
Re-use of ex-LEP refrigerators to be upgraded for LHC requirements
Site constraints for infrastructure => 5 islands 1.8K Refrigeration units to be connected to all
types of 4.5K refrigerators
General features:• Cool-down & Warm-up: 600kW• No global redundancy but doubling critical items• Impurities: continuous capacity for 50 ppm(v) air, water
S. Claudet - 31st May 2007 Power refrigeration for LHC
Layout of LHC CryogenicsLayout of LHC Cryogenics
Pt 3
Pt 4
Pt 5
Pt 6
Pt 7
Pt 8
Pt 1
Pt 2
Pt 1.8
Cryoplant DistributionPresent Version
Cryogenic plant
8 x 18kW @ 4.5 K
1’800 sc magnets
24 km & 20 kW @ 1.8 K
36’000 t @ 1.9K
130 t He inventory
S. Claudet - 31st May 2007 Power refrigeration for LHC
ContentContent
Introduction
Required capacity and system architecture
4.5 K Refrigerators and 1.8 K Units
Recent achievements
Conclusion
S. Claudet - 31st May 2007 Power refrigeration for LHC
Heat loads for a sectorHeat loads for a sector
Required capacity = Fo x (Fu.Qs + Qd)
• Fu: Uncertainty on static loads
• Fo: Overcapacity
Qs: Static heat leaks
Qd1: Dynamic « current »
Qd2: Dynamic « beam »
Early heat load inventory and follow-up, periodic update of cryogenic architecture and distribution scheme
S. Claudet - 31st May 2007 Power refrigeration for LHC
Demands in refrigerationDemands in refrigeration
Evaluation of heat loads (static, dynamic)
Required capacity with appropriate margins
Convertion in Demands for Refrigeration
Process studies to validate feasibility
1
3
2
S. Claudet - 31st May 2007 Power refrigeration for LHC
Possible cooling cyclesPossible cooling cycles
CC
CC
CC
LHe
Sub-atmosphericcompressor
4.5
K r
efrig
erat
or
Heat load
HP
MP
LP
1
2
3
“Mixed” Compression
P ratio ≈ 80
HX
Installed capacity: 125 g/s @ 15 mbar(i.e. ~2,4 kW @ 1,8 K)
Turn-down capability: 1 to 3
Return temperature at the 4.5 K Refrigerator: - Reduced mode: ≤ 30 K - Installed mode: ≤ 20 K
‘Stand alone’ capacity check (B interface closed)
Process & components identified as a challenge
Validation prior to series (1+n)
0.3 MPa4.6 K
0.13 MPa,20 -30 K
WC
S
1.8
K R
efri
ger
atio
n U
nit
LHe 1.8 K Q1.8K
CC
B
4.5 KRefrigerator
B
D
C
Col
d co
mpr
esso
rs
Tur
blne
Adsor-bers
LHC SectorLoad
S. Claudet - 31st May 2007 Power refrigeration for LHC
Cryogenic architectureCryogenic architecture
Warm CompressorStation
Upper Cold Box
Interconnection Box
Cold Box
Warm CompressorStation
Lower Cold Box
Distribution Line Distribution Line
Magnet Cryostats Magnet Cryostats
Cold Compressorbox
Warm CompressorStation
Cold Compressorbox
Warm CompressorStation
Shaft
Sur
face
Cav
ern
Tu
nnel
LHC Sector (3.3 km) LHC Sector (3.3 km)
1.8 K Refrigeration Unit New 4.5 K Refrigerator Ex-LEP 4.5 K refrigerator 1.8 K Refrigeration Unit
Typical LHC even point
S. Claudet - 31st May 2007 Power refrigeration for LHC
Checking all modesChecking all modes
At early project phase
S. Claudet - 31st May 2007 Power refrigeration for LHC
ContentContent
Introduction
Required capacity and system architecture
4.5 K Refrigerators and 1.8 K Units
Recent achievements
Conclusion
S. Claudet - 31st May 2007 Power refrigeration for LHC
Procurement strategyProcurement strategy
Sub-systems by type of functionality:• CERN defined interfaces and required performance
Great majority procured from industry:• Competitive performance based tendering
(capital and operation cost)
• Detailed studies, manufacturing, site installation, commissioning, performance assessment
Separate management of general services:• Interconnecting piping, controls, site utilities
S. Claudet - 31st May 2007 Power refrigeration for LHC
Construction phaseConstruction phase
Industry available products:(storage tanks, piping, 4.5K refrigerators)
• Functional technical specifications adapted => tests
Extension of existing products(1.8K units, cryogenic lines, superconducting links)
• Complex performance & possible impacts
• CERN add. design & support to fabrication
Totally new products(Rad. tol. cryo thermometry - electrical feed boxes)
• CERN with full responsibility for developments and “built to print” fabrication contracts
S. Claudet - 31st May 2007 Power refrigeration for LHC
LHC 18 kW @ 4.5 K RefrigeratorLHC 18 kW @ 4.5 K Refrigerator
Compressor stationsCompressor stations
S. Claudet - 31st May 2007 Power refrigeration for LHC
LHC 18 kW @ 4.5 K RefrigeratorLHC 18 kW @ 4.5 K Refrigerator
Process cycle for Air LiquideProcess cycle for Air Liquide
S. Claudet - 31st May 2007 Power refrigeration for LHC
LHC 18 kW @ 4.5 K RefrigeratorLHC 18 kW @ 4.5 K Refrigerator
Process cycle for LindeProcess cycle for Linde
S. Claudet - 31st May 2007 Power refrigeration for LHC
18 kW @ 4.5 K Refrigerators18 kW @ 4.5 K Refrigerators
33 kW @ 50 K to 75 K - 23 kW @ 4.6 K to 20 K - 41 g/s liquefaction
P input : 4.2 MW
COP
< 250 W/W
S. Claudet - 31st May 2007 Power refrigeration for LHC
1.8K Refrigeration units1.8K Refrigeration units
3.5 bar 6.5 bar0.50 bar
0.35 bar
4.0 bar
S. Claudet - 31st May 2007 Power refrigeration for LHC
2400 W @ 1.8K Refrigeration units2400 W @ 1.8K Refrigeration units
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1985 1993 2000Year of construction
Ise
ntr
op
ic e
ffici
en
cy [%
]
Tore Supra
CEBAF
LHC
Diam: 250mm
S. Claudet - 31st May 2007 Power refrigeration for LHC
ContentContent
Introduction
Required capacity and system architecture
4.5 K Refrigerators and 1.8 K Units
Recent achievements
Conclusion
S. Claudet - 31st May 2007 Power refrigeration for LHC
Progress overviewProgress overview
QSCB
Sector 1-2 Sector 2-3 Sector 3-4 Sector 4-5 Sector 5-6 Sector 6-7 Sector 7-8 Sector 8-1
QSRB
QURA
QUIAQUIB
Point 4Point 2Point 1.8 Point 6 Point 8
Sur
face
Cav
ern
QURC
QSCA QSCA QSCB
QSRB QSRB
QSCB QSCAQSCA QSCB
QSRB
QURC QURC QURC QURC
QUIC QUIC
QURA
Sha
ft
QSCC QSCC QSCC QSCC QSCC
Tun
nel
Storage Storage Storage Storage Storage
QURAQURA
Legend
Cryogenic Distribution Line
QSC_(A,B,C):QSR_(A,B):QURA:QURC:QUI_(A,B,C):
Warm Compressor StationSurface 4.5 K Refrigerator Cold BoxUnderground 4.5 K Refrigerator Cold Box1.8 K Refrigeration Unit Cold BoxCryogenic Interconnection Box
Commisionned & accepted
Under commissioning
Delivered / Under installation
Under fabrication
Ordered (Contract placed)
Under definition
Electrical Feed Box
Superconducting Link
QURC
QSCC
QSRA QSRA QSRA QSRA
QURC
QSCC QSCC
QURC
QUIC
S. Claudet - 31st May 2007 Power refrigeration for LHC
LHC sector 78 - First cooldown
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Time (UTC)
Tem
per
atu
re (
K)
Supply temperature Magnet temperature (average over sector)
Return temperature Thermal shields temp. (average over sector)
Thermal shield
temp.Supply
temperature
Return
temperature
Magnet
temp.
Re-start of active cooling for cryogenic
transfer lines
Re-start of active cooling for magnets
4.5 K
20 K
80 K
S. Claudet - 31st May 2007 Power refrigeration for LHC
Ready to prepare for
2 K powering
tests
S. Claudet - 31st May 2007 Power refrigeration for LHC
Ready for 2 K powering
preparation
Ready to prepare for 2 K powering tests
S. Claudet - 31st May 2007 Power refrigeration for LHC
ConclusionConclusion
It has been possible to design, built, install and validate all LHC refrigeration sub-systems
Within a few weeks (2 to 6), the tuning with the 1st LHC sector has been made to allow magnet powering tests
Early indications have to be evaluated (heat loads, response time, controls, availability)
LHC commissioning: We are confident, and aware that it represents an enormous challenge with learning process, efforts and surprises!
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