Design, Construction, Installation and first Commissioning ...

Design, Construction, Installation and first

Commissioning Resultsof the

LHC Cryogenic SystemSerge Claudet (CERN, Geneva)

On behalf of the “Cryogenics for Accelerator” groupand the hundreds of people involved

S. Claudet - EPAC'06 Edinburgh LHC Cryogenic system: 1st experience

Thanks to contributors

• A. Ballarino• Ch. Balle• J. Casas• J-P. Delahaye• G. Ferlin• Ph. Gayet• Ph. Lebrun• F. Millet

• C. Parente• G. Riddone• L. Serio• L. Tavian• R. Van Weelderen• B. Vullierme• U. Wagner


Content

• Introduction• Design challenges and R&D outcome• Procurement, Construction & Installation• First commissioning experience• Main problems encountered• Considerations for new projects• Conclusion

90ies

‘02 - ‘06‘98 - ‘06


LHC accelerator

24 km of superconducting magnets @1.8 K, 8.33 T

p-p collision 1034 cm-2.s-1, 14 TeV, 0.5 GJ stored energy

Early requirements for

the LHCcryogenic system


Layout of 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

100 t He inventory


Cryogenic architecture

Warm CompressorStation

Upper Cold Box

Interconnection Box

Cold Box


Lower Cold Box

Distribution Line Distribution Line

Magnet Cryostats Magnet Cryostats

Cold Compressorbox


Cold Compressorbox


Shaft

Surfa

ceC

aver

nTu

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


0

20

40

60

80

100

120

140

160

180

1960 1980 2000

Year

OMEGA,BEBC,

ISR Low-Beta

ALEPH,DELPHI,

LEP Low-Beta

LEP2

LHC, ATLAS, CMS

LEP2+

LHC

: 14

4 kW

LHCCooling capacity

How does it compare ?

Tevatron, RHIC,Jlab, SNS, HERA,

Tristan, …

ITER

0

50

100

150

200

250

300

Tevatr

on

HERA

CEBAF

RHIC

LEP2

LHC

(SSC)

[tonn

es]

VirtualLiquidGas @ 2 MPa

Helium Inventory

Unprecedented !

1

10

100

1000

10000

1 10

T [K]

P [k

Pa]

SOLID

HeII HeI

CRITICAL POINT

GAS

λ line

Saturated He II

Pressurized He II

1

10

100

1000

10000

1 10

T [K]

P [k

Pa]

SOLID

HeII HeI

CRITICAL POINT

GAS

λ line

Saturated He II

Pressurized He II

Superfluid Helium 1.8 K


Design

• Site constraints and general concerns

• Early heat load inventory and follow-up, periodic update of cryogenic architecture

• Components and system R&D:– Early industry involvement– Dedicated tests facilities


Magnet cooling scheme

1

10

100

1000

10000

1 10

T [K]

P [k

Pa]

SOLID

HeII HeI

CRITICAL POINT

GAS

λ line

Saturated He II

Pressurized He II

1

10

100

1000

10000

1 10

T [K]

P [k

Pa]

SOLID

HeII HeI

CRITICAL POINT

GAS

λ line

Saturated He II

Pressurized He II

Thermo-hydraulics of two-phase flow

in He II

(and limitations!)

(≈ 1W/m)


1.8 K issues

CC:- 3D wheels- Bearings (300K)HX:- Very Low Pressure

CC

CC

CC

LHe

Sub-atmosphericcompressor

4.5

K re

frige

rato

r

Heat load

HP

MP

LP

1

2

3

“Mixed” Compression P ratio ≈ 80

HX Stainless Steel Plate

Axial-centrifugalImpeller (3D)

Fixed-vanediffuser

3-phase inductionElectrical motor(rotational speed: 200 to 700 Hz)

Activemagneticbearings

300

K un

der

atm

osph

ere

Cold

und

erva

cuum

Inlet

Outlet

Pressure ratio2 to 4

Spiral volute

200 to 800 Hz)

Cold Compressor


Thermometry6’000 units, +/- 10 mK @ 2K in LHC radiation conditions

From ‘sensor’ to ‘thermometer’ with signal processing


Other R&D examples

• HTS current leadsTotal: 3.4 MA

1200 units600-6000-13000 A

BSCCO 2223

• Thermal design:– Low temperature insulation– Heat intercept techniques

20 l/m @ 1.9 K 100 m3 @ 20 K 2000 m3@ 300 K

• Safe cryo-magnets resistive transition:– Cascade: cryostat - cold recovery header - MP tanks– Specific cold safety relief valves


LHC test string

More than 20’000 hours of operation of the LHC Test Strings

1.7

1.75

1.8

1.85

1.9

1.95

2

10:50 11:00 11:10 11:20 11:30 11:400

2

4

6

8

10

12[kA], W/m[K]

0.2 W/m 0.3 W/m - 0.6 nOhm

T stability duringMagnet powering

0

5

10

15

20

25

30

35

0 20 40 60 80 100 120 140 160 180

time,s

[K],

[bar

], [V

]

0

2

4

6

8

10

12

QV9202SIQV920

Quench MB5 , 37s

Quench MB6 , 72s

pressureT MB5

T MB6

T MB4

T MB1, MB2, MB3

P evolution during quench at 13’000 kA


Procurement• Sub-systems by type of functionality:

– CERN to define interfaces and required performance

• Great majority procured from industry:– Competitive performance based tendering

– Detailed studies, manufacturing, site installation, commissioning, performance assessment

• Separate management of general services:– Interconnecting piping, controls


Construction phase• Industry available products:

(storage tanks, piping, 4.5K refrigerators)– Functional technical specifications adapted (tests)

• Extension of existing products(1.8K units, cryogenic lines, electrical feed boxes)– Complex performance & possible impacts– CERN add. design & support to fabrication

• Totally new products(Rad. tol. cryo thermometry - superconducting links)– CERN with full responsibility for developments and

“built to print” fabrication contracts

Projects

OP


Industrial fabrication sites

European abrication sites for LHC Cryogenics

And from USA, Russia, Japan, …

Main distribution line:Dedicated assembly sites to cope with ’’relative’’ modularity

215 standardpipe elements

30 fixed points & vacuum barriers

17 special service mod. + 1 return mod.

18 standardservice modules

2 double-jumper service module

30 special pipe elements

2 steps 6 elbows 1 test module

Important issues:Qualification, procedures, supply

chain, follow-up, Quality assurance


Electrical feed boxes

Assembly of current leads cartridges

Final assembly and tests

Assembly of DFBM, DFBL, LCM

Assembly of DFBA HCM

Components

Assembly of the busbar bundles

Assembly of the Arc Termination Module (ATM)

Final assembly + tests

CL cartridges assembly area

CL modules assembly stands

Global leak test of DFBMPressure test area for DFBAs

Assembly of DFBA shuffling boxes

DFBA busbar bundles lambda plates

AT-ACR

IHEP / AT-ACR

TS-MME

ICS / AT

Towards an integrated factory !

Mechanics - Electricity - Cryogenics


Installation phases

Helium storage tanks

Compressors

Cold Box close to access shaft

Powering sub-station

Cooling towers

Important issues: logistics, handling, co-activity, quality


Installation & tests

Cryoplants

Interconnection box

MP storage< 20 bar

Purge line

TunnelCavernsSurface

Warm Recovery Line (WRL)

Vent

Lin

e (V

L) To atmosphere

B

E

D

C

F

QRL & Machine

Cold He with HPWarm He with HPWarm He with LPAir

Cold compressor box

PT

Equipment under installation already connected to cryogenic equipment under operation or commissioning …

- Tappings

- Two valves in series

- Padlocks


Commissioning• Commissioning of each sub-system:

– Mechanical pressure test, helium leak test– Input/output signal tests– Operational tests to demonstrate all functions– Performance measurements (ref. capacity, thermal losses)

• Subsequent commissioning in cascade:– Potential problems identified early and clearly– Possible actions before it becomes critical

• Global LHC Hardware Commissioning:– A Crucial test for many systems, incl. cryogenics– Project wide coordination efforts, incl cryogenics

Projects

OP


Magnet cold tests


Cryogenic sub-systems

Point 8Storage

Sector 7-8 Sector 8-1

Surf

ace

Cav

ern

QSCA QSCB

QSRB

QURC

QUIC

QURA

Shaf

t

QSCC QSCC

Tunnel

QURC

QSRA


18 kW @ 4.5 K Refrigerators33 kW @ 50 K to 75 K - 23 kW @ 4.6 K to 20 K - 41 g/s liquefaction

Pinput : 4.2 MW

Carnot Limit

COP

250 W/W


2400 W @ 1.8K units

1.8K refrigeration units1st Pump-down in final LHC configuration

0.000.05

0.100.15

0.200.250.30

0.350.40

0.450.50

7:12 8:24 9:36 10:48 12:00

Time

0

500

1000

1500

2000

2500

Coo

ling

Pow

er [

W]

Suction Pressure

Set point

1.8K Cooling Power

P8 - 7 April 2005

Installed mode 2400 W @ 1.8 K

Pump-down 15 mbar

0

10

20

30

40

50

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80

1985 1993 2000Year of construction

Isen

tropi

c ef

ficie

ncy

[%]

Tore SupraCEBAF

LHC

Diam: 250mm


Main cryogenic line

634 +/- 50 (~0.2 W/m)

593

B+C+D (4-20 K)

9000 +/- 400 (~ 2.8 W/m)

Measured

9850Calculated

E+F (50-75 K)

Heat inleaks [W]


Cryogenics P&F diagram

A large and complex fluid distribution system

More than 100 PIDcontrol loops

Towards modern predictive controls …


Progress overview

Staggered progress by ‘‘LHC Point’’ then by sub-system


Main problems !• Very specific “troubles” not even mentioned

• Design & sub-system concerns– Cryogenic lines ( x 3 )– Electrical heaters for cryogenic flows ( x 2 )– Impurities (dust) remaining from fabrication– Controls– Coordination for “built to print” sub-systems ( x 2 )

• General concerns– 3D models, transport items to place, QA tools– “Time is contingency” to “Keep on schedule” takes time!


Main cryogenic line (1/2)E

F

BD

C

E

F

BD

C

Φ= 650 mmE-F= 50-75 B,C,D = 4-20 K

Weak mechanical approach and quality assurance


Main cryogenic line (2/2)“C” type interconnections

“A” type interconnections

Special interconnections

2nd start has been the

good one, after

complements by CERN

Double sourcing ?


Electrical heaters

Combination of heat exchange, flow patterns, electrical and

integration analysis

New design

Chicane Filler piece

Thermal screens

600 kW ElectricalHeater

D ≈ 500 mmL ≈ 3.5 m


SH6

US IP6

SUH6

QURA-1

QSCA-1/2

QURCa-1

QSA(a)

QURCb-1

QSCCb

QSCB

QUI

QSDN

Ethernet backbone (IT-CS)

Ethernet surface Infrastucture (IT-CS)

Comp 4.5KComp 1.8K Comp 1.8K Comp 4.5K Main Dryer

QURCa-2

QURCb-2

QURA-2

QSRB-1/2Cold Box 4.5K LN2 BufferGhe Buffer

CB 1.8KCB 1.8K

LCB4.5K

ConnectionBox

SHM6 SD6

QSRA-1/2UCB 4.5K

Ethernet underground Infrastucture (IT-CS)

QSKAQSA(b)QSCCa QSV

Main Dryer

SCADA data servers

LHCALHCCa

LHCCb

LHCB

Ethernet local connection (LHC-IAS/IT CS)

1.8K 1.8K4.5K 4.5K

DS1 DS2

OS1OS2

OS3OS4

EW1

EW2230v

Alcove AlcoveUS IP5(b)

DFB

AlcoveAlcove US IP7(a)

DFB

Sector DFB

DFB

Sector

OS1OS2

OS3OS48 x 30 PLC’s

8 x 10’000 I/O

Controls

Industrial PLC’s, Ethernet based communications and object

oriented sofware:High potential, reliability being

improved


Considerations for new projects

• LHC public documentation:• Each new project has its own constraints!

Identification of boundary conditions and technological evolution since last project:– Partnership: an efficient way to catch faster– If necessary, R&D and components validation

• For design & installation: solid referencescompleted by flexibility

• Take advantage of experienced teams while they exist!

www.cern.ch/lhc> LHC Design Report > Cryogenics> LHC Project Reports : Papers


Conclusion

• Installation of various cryogenic sub-systems and cold tests of LHC cryo-magnets will be mostly completed by end of 2006

• All cryogenic sub-systems commissioned so farfulfil their requirements

• First LHC sector cool-down and commissioning end 2006:

Confident, and aware that it represents an enormous challenge with learning process, efforts and surprises!

Design, Construction, Installation and first Commissioning ...

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