lhc cryogenics from cool-down to 1st beams

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

LHC CryogenicsFrom cool-down to 1st beams

Serge Claudet (LHC Cryo OP),

On behalf of cryo teams involved

S. Claudet LHC Cryogenics - CryoOps 2008

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Content

• Introduction to LHC cryogenics

• Cool-down, cryo tuning for magnets HWC

• Functional analysis - Controls - Availability

• Perspectives

• Summary


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.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

120 t He inventory


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.LHC Cryogenics architecture

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

Surface

CavernQURC

QSCA QSCA QSCB

QSRB QSRB

QSCB QSCAQSCA QSCB

QSRB

QURC QURC QURC QURC

QUIC QUIC

QURA

Shaft

QSCC QSCC QSCC QSCC QSCC

Tunnel

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

Large variety of large scale refrigerators,AND

Large variety of valve boxes and large scale lines


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Cryogenic sub-systems

Point 8Storage

Sector 7-8 Sector 8-1

Su

rface

Cavern

QSCA QSCB

QSRB

QURC

QUIC

QURA

Sh

aft

QSCC QSCC

Tu

nn

el

QURC

QSRA

Qualified with performance assessment before being

put together


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.LHC Sector 4-5 scheme

4.5 K1.9 K

3.3 km4’700 t @ 1.9K≈ 10/15tHe



LT836LT837

LT864LT865

LT866LT867

≈ 5 m

Electrical Feed Boxes (DFB’s)






• Perspectives

• Summary


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Flushing sectors before cool-down

Dust Debris Kapton Reports

And possible shorts in diodes !

But the sooner the best !!!



First cool-down of LHC sectors

0

50

100

150

200

250

300

12-Nov-2007

10-Dec-2007

07-Jan-2008

04-Feb-2008

03-Mar-2008

31-Mar-2008

28-Apr-2008

26-May-2008

23-Jun-2008

21-Jul-2008

18-Aug-2008

15-Sep-2008

Temperature [K]

ARC56_MAGS_TTAVG.POSST ARC78_MAGS_TTAVG.POSST ARC81_MAGS_TTAVG.POSST ARC23_MAGS_TTAVG.POSST

ARC67_MAGS_TTAVG.POSST ARC34_MAGS_TTAVG.POSST ARC12_MAGS_TTAVG.POSST ARC45_MAGS_TTAVG.POSST

Christmas and water maintenance shut-down

Short in connection

cryostats and repairs

Ope

n Da

ys

Cooling 8 sectors + Cryo tuning + Powering tests activities

UX85 Ph1

works

All sectors at nominal

temperature

Simultaneous Cryo start/maintain

First beams around LHC

First cool-down of LHC sectors


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Cool-down speed for LHC sectors

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300

Temperature moyenne du secteur [K]

Vitesse de mise en froid [K/jour]

Secteur 7-8 #1Secteur 4-5Secteur 5-6Secteur 7-8 #2Secteur 8-1Enveloppe 1Enveloppe 2

Availability for LN2 (trucks & staff)

Cool

-dow

n sp

eed

[K/d

ay]

Average temperature of magnets [K] Dispersion due to particular process (HX & Turbines) and timing for thermal shield/ Line B


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.An idea of time constants !

m’ = Ro . V . SFrom QUI to

QRL_RM

≈ 3300m

Changes on « supply conditions » may have an effect some hours later …

Diam. [mm] Volume [m3]C 100 25.9D 150 58.3B 250 162.0

Density [g/l] Mass [kg] Time flightC [3B, 5K] 118 3058 5 - 12hD [1.3, 8K] 8 467 1 - 4hB [0.015, 4K] 0.18 29 4 - 12'

E

F

BD

C

E

F

BD

C



Present reference with Jun’08 constraints(staff, LN2, controls)

25 d

3 d

2 d

LHe

18 d

2 d

1.5 d

Updated installed capacity

At best:21.5 d

Duration of phases

Target 2008:5 wks


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.LHC Cryogenic commissioning• 4.5K stand-alone magnets

– Cool-down to < 10K– Adjust instrumentation LT/EH– Control LHe at 50% Fill-up and boil-off to determine

appropriate set-point

• Electrical Feed Boxes (DFB’s)– Cool-down shield (if any)– Cool-down leads at 150K, then cool-

down phase separator– Adjust instrumentation LT/EH– Control LHe at nominal Fill-up and boil-off to determine

appropriate set-point Tuning of Temp. control loops

• 2 K magnets in ARC– LT/EH at return modules

– LT of SSS in ARC

– EH at lowest point

– EH of cold masses & beam screens

Possible pump-down and cool-down of magnets, including tests with cold compressors

Identified and tuned for sector 4-5,

Implemented for sector 5-6, 7-8, and now in 8-1, 2-3, 6-7 during the (target =two) weeks after ARC magnets @ 4.5K


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Recovery Time after Limited Resistive Transitions

• More than 14 cells or full sector: recovery up to 48 hours• In case of fast discharge (even w/o quench): 2 h recovery (heating due to eddy currents)

(Predictions at design stage)

Achieved or achievable

From x3 down to x1.5 w.r.t design values

Without losing helium, and powering permit on other powering subsectors






• Perspectives

• Summary


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Cryogenics P&F diagram

A large and complex fluid distribution system !

More than 500 PID control loops

Complete functional analysis:

- global process phases and families

- automation request for each phase

- synoptics

- “propagate order” tools



Standard cells (≈27)

QRLFilling valves

Q D DD

• Cool-down using mostly Flow controlers

• P, T, L controlers at operating conditions

Q D DDQ D DDQ D DD

Magnets 1.9K control

Beam screen T control



Electrical feed boxes (4 to 8)

QRL

• Cool-down using mostly Flow controlers

• T, L controlers at operating conditions

Filling valve

Current leads

control


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Cryo conditions for powering

Cryo Start: set of conditions to allow powering of concerned sub-sector (rather strict = good stability of process)

Cryo Maintain: Few important conditions checking integrity of HW, with slow power abort in case this signal is lost


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.LHC Cryogenics power permit

The cherry on the cake ! 20 months after start of cool-down


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Downtime - Availabilitysector 56 origin (hrs) stop (hrs)

1 29-Feb-08 Elec 2.0 Stop 400V (Pb AUG loop) stop CC 1682 12-Mar-08 Cryo 0.0 Controls CC (AL) stop CC not applicable3 14-Mar-08 Cryo 48.0 Leak in 18kW Cold Box stop CC 2404 02-Apr-08 Cryo Controls CC (AL) stop CC not applicable5 04-Apr-08 Cryo Stop 18kW Comp. (LS oil) stop entire sector not applicable6 04-Apr-08 Water Stop 400V P5 (water) partly blind not applicable7 06-Apr-08 Cryo Stop 18kW Comp. (LS oil) stop entire sector not applicable8 18-Apr-08 Elec 0.0 Low 400kV stop CC 969 30-Apr-08 Elec 0.0 CERN 400kV failure stop entire sector 120

10 04-May-08 Elec US65 400V stop stop CC not applicable11 10-May-08 Elec US65 400V stop stop CC not applicable12 10-May-08 Elec US65 400V stop stop CC not applicable13 11-May-08 Elec 0.0 24 VDC power unit down stop entire sector 8014 22-May-08 Elec 0.0 US65 400V stop stop CC 2415 30-May-08 Elec 2.0 US65 400V stop stop CC 12016 29-Jun-08 Water 1.0 SF6 stop, too high temp. stop entire sector not applicable

0

24

48

72

96

120

144

168

192

216

240

264

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Original failure [hrs]

Cryo recovery time [hrs]

stop sector

stop CC

LEP Bonus/Malus

LHC estimates

Rather good availability already a few weeks after 5 TeV qualification Failure rates of services to be improved Cryo recovery time to be improved with more robust automation

Open Days

Training Quenches

Power failures

Promising period !

Target Autumn’08: < 12 h for stop CC [OK] < 36 h for full sector stop [24h]






• Perspectives

• Summary


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Organisation of resources

• Cool-down of 8 sectors:– Performed with “cryo island” based teams

• HWC of many sectors in parallel:– Since mid Jan’08, operators up to 22h and Saturdays– 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:– End of present operation contract, with in-sourcing plus “Field

Support Unit” as reference solution, to be re-evaluated end 2008

Sept. to Nov’08: 2 x (3x8h-7d/7d) in CCC

LHC Cryo OP

Learning to master LHC cryogenics, education of teams while updating controls based on ecperience, towards sites-machines-operations duties


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.Summary

• Confirmation of cooling principle, heat loads, thermometry channels, machinery, global system behaviour

• The LHC cryogenic system has been progressively put into service with obvious signs of “learning curve”, and promising periods for possible beams

• Consolidation program started and continued (valves, DFB’s, instrumentation & controls, helium guards) now extended as well to services

• Slowly preparing the switch from HWC to operation for beam, with reasonable confidence but with minimal tools and staff

lhc cryogenics from cool-down to 1st beams

Documents

mlhc cryogenics cryoops

klhc cryogenics cryoops

wkslhc cryogenics cryoops

schemelhc cryogenics

lhc cryogenicscool

lhc sectorsavailability

cooldown of magnets

lhc cryogenicsfrom cooldown