H. Herzog, 22th-26th September 2008 Cryogenics Operations 2008, CERN, Geneva, Switzerland 1...

H. Herzog, 22th-26th September 2008Cryogenics Operations 2008, CERN, Geneva, Switzerland

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CRYOGENICS OPERATIONS 2008

Organized by CERN

LARGE SCALE CRYOGENIC LARGE SCALE CRYOGENIC SYSTEMSYSTEM

Hermann Herzog


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Large scale cryogenic system

• The DESY Lab; Intro• The HERA Cryogenic System• Operational History• Availability, Reliability• Operational Experience• Failures• Summary


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The Research Centre DESY

• Aerial view of the Lab


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• Aerial view of the Lab


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• Budget• Finance• Permanent Staff• Education• International Cooperation• Permanent guest research

groups• Users of the DESY facilities


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• Long tradition on cryogenics @ DESYLong tradition on cryogenics @ DESY

• 1964 H2 Liquefier 45l/h, bubble chamber

• 1970 He Liquefier, 12W• 1972 He Liquefier, 200W, PLUTO• 1979 He Liquefier, 200W, CELLO• 1982 He Liquefier, 900W, cryostat devlp.• 1985 He Liquefier, 300W, s.c. cavity HERA• 1985 3x large He Liquefier, HERA


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Long tradition on cryogenics @ DESY

1964 -1972H2 Liquefier45l/h forBubble Chamber


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• 1982He Liquefier 900WHERA Cryostatdevelopment, s.c. cavities


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• 1985He Liquefier 300Ws.c. cavity test facility


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• 1985 3 large He-Refrigerators for HERA


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Overview Current (HERA-) Cryoplant

N

O

S

W

CBX1

CBX2

CBX3

H1

ZEUS

HERMES

s.l. Cavities

Referenz Magnete

FLASH

CMTB

SMES

MTH


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Operational history of the HERA cryoplant

EVENT TIME

HERA approved May 1984

Construction of the cryogenic plant 1985 + 1986

Commissioning of the first cold box 1987

Cryogenic supply of the magnet test facility 1987 – 1990

Installation of the helium distribution system in the ring tunnel 1988 – 1989

Installation of the 646 s.c. proton ring magnets in the tunnel 1989 – 1990

First cool down of a HERA octant May 1990

Cool down of all HERA magnet octants End of 1990

First stored proton beam April 1991

Installation of 16 s.c. cavities in the electron ring 1991 – 1992

Experiments H1 and ZEUS enter the beam line Dec./Jan. 1991/1992

Nominal proton energy (820 GeV) reached March 1992

Luminosity to the experiments, start of the experim. ProgrammeCryo systems steady state cond. @4.4K (1030 mbar)

June 1992

1st test of one cryo system @4K for 24 hs Nov. 1993

Installation of additional transfer line and feed box for experiment HERMES 1995

2nd run of complete cryo system @4K for 2 months Oct. + Nov. 1997

Proton ring upgrade to 920GeV, cryo systems operates now @4K (650 mbar)

July 1998

Installation of FEL-distribution, cryogenics supply to the VUV-FEL (TESLA-Test Facility) 1998

Installation of 4 s.c. magnets in the interaction – area (lumi-upgrade) 2000

Installation of 2 frequency controlled motor drives (upgrade to two JT compressors) March 2003

Installation of 5 frequency controlled motor drives (upgrade to five JT compressors) Nov. 2005

End of HERA-run, cryo systems operating stopped July/31/ 2007


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Basic Agreement DESY-LINDE

• Operation and maintenance of the Cryoplant under full responsibility of LINDE KRYOTECHNIK AG

all operational funds 7 high skilled professionals

part of the manpower

all spare parts


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Operational experience

• Shift system• 6 shift crews• 24/7/12 at least 1 operator on shift

D E S Y - Shiftplan C R Y O - Plants : SEPTEMBER 2 0 0 8

Weekday >>> Mon Thu Wed Thu Fri Sat Sun Mon Thu Wed Thu Fri Sat Sun Mon Thu Wed Thu Fri Sat Sun Mon Thu Wed Thu Fri Sat Sun Mon ThuTime \ Datum 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

07:00 - 15:30 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5 5 5 5 515:00 - 23:30 4 4 4 4 5 5 5 5 5 5 6 6 6 6 6 6 1 1 1 1 1 1 2 2 2 2 2 2 3 323:00 - 07:30 5 5 6 6 6 6 6 6 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4


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Item Failure reason Failure rate

Screw Compressors fail to operateshaft seal excess leakcapacity control fail to operate

Motors ball bearing damaged

Oil pumps shaft seal excess leakoil leak > 5 l / 1000 hs

Control valves (air operated)

fail to operateleak past the seat

Motor driven fan (oil cooler)

ball bearing damagedv-belt broken

Liquid He level sensor erratic indication

Electrical switches, contacts, transformer, power supplies

thermal current switches failcircuit breaker fails to operate

Process control computer system

system fail to operatecrates fail to operate

Instrumentation, pressure transmitter, flow meter,

erratic outputcapillary plugging

Cold cathode vacuum gauge

erratic indication


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Item Interval Description

Compressors

Coupling adjustment

general overhaul every 25.000 hs

every year

Inspection of bearingsExchange of all sealing'sFunctional testcheck alignment

Motors general overhaul every 25.000 hs

Inspection of bearingsInsulation bath of the motor windings

Oil pumps oil leak > 5 l / 1000 hs Exchange shaft seal

Valves every 2 years Leak test, gauge

Adsorbers every 2 years Leak test

Purifiers every 2 years Leak test,

Electrical switches, contacts, transformer, power supplies

every 2 years General cleaning, inspection, test and gauge

Process control system every 2 years continuously

Hardware exchanges, Software upgrades, Program updates

Instrumentation, pressure transmitter, flow meter, pressure and temperature switches

every 2 years Test and gauge, pump and purge plugged capillaries

vacuum pumps general overhaul every 2 years

exch. cold cathode vac. gauge


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Failure statistics

HERA Cryogenics: Failure statistics CRYOPLANT over 16 years 1992 - 2007

0

20

40

60

80

100

Compr. ProcessComputer

Power Water Pneum. Air

Failure Reason

# F

ailure

s

0

100

200

300

400

500

600

Dow

nti

me S

um

(h)

HERA Cryogenics: Failure statistics CRYOSUPPLY over 16 years 1992 - 2007

0

20

40

60

80

100

Compr. ProcessComputer

Power Water Pneum. Air

Failure Reason

# F

ailure

s

0

100

200

300

400

500

600

Dow

nti

me S

um

(h)

But this is the failure statisticsIncluding infrastructure ofHelium users!

Failure statistics of refrigerating plant only.


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Summary

• Throughout 17 years of HERA-operation the refrigeration plant compensated the cryogenic loads of the HERA accelerator, the HERA experiments and temporarily the FLASH accelerator and other recipients with a corresponding availability of 98,7 %.

• Related to the availability of the refrigeration plant itself this value exceeds 99 %.

A plant-availability of 99 % is possible if periodical maintenance as well as the exchange of critical components (O-ring sealing, power supplies, emergency-power supplies, PLC’s, etc) is carried out.

H. Herzog, 22th-26th September 2008 Cryogenics Operations 2008, CERN, Geneva, Switzerland 1...

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