SC - 04Feb'13Cryo Heaters Review Cryogenic Heaters Review Operation use and wishes S. Claudet - A. Suraci LHC Cryogenic Operation.

SC - 04Feb'13 Cryo Heaters Review

Cryogenic Heaters Review

Operation use and wishes

S. Claudet - A. SuraciLHC Cryogenic Operation

SC - 04Feb'13 Cryo Heaters Review

Content

• Introduction

• Why/how we use heaters

• What we would like to have

• Summary

SC - 04Feb'13 Cryo Heaters Review

From LHC Magnet String testx 13.5

Sector 3.3km

Introduction to 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

Distribution

Magnets

8 x 18kW @ 4.5K24km & 20kW @ 1.8K

36’000 t @ 1.9K130 t He inventory

Heaters:

10-30 kW

600 kW

25 - 100 W - 1 kW

SC - 04Feb'13 Cryo Heaters Review

4.5K Refrigerators (QSRB)

Level Control (PID)

SC - 04Feb'13 Cryo Heaters Review

1.8K units (QURC)

SC - 04Feb'13 Cryo Heaters Review

Interconnecting Box (QUI)

600 kW

Level Control (PID)

SC - 04Feb'13 Cryo Heaters Review

Cryogenic Line (QRL)

No bad experience with heater command

Level Control (PID)

Fixed value

SC - 04Feb'13 Cryo Heaters Review

Electrical Feed Boxes (DFBs) or Stand-alone magnets

No bad experience with heater command

Fixed value

SC - 04Feb'13 Cryo Heaters Review

Standard cells (magnets + beam screens)

Few mishaps with power kept ON, local intervention by specialists required !!!

To provide minimum

flow to CCs

So far 25 W,

Later on for bake-out (200W)

Temperature Control (PID)

SC - 04Feb'13 Cryo Heaters Review

What we would like to have• DO: ON-OFF independent from Analog request (New)

– Logic conditions to switch it ON/OFF (operators for special cases)

• DI: Safety switch ON/OFF (setting tuned by referent specialist)– If it comes once, temporary stop for both DO and AO– If it comes 3 times in less than 2 hours, full stop

• AO: Analog request for power– As done now

• AI: Analog measured power [AI]– Feedback of dissipated power (if it exists)

• + Regulation switch or value (independent from safety)– HW (iron-like) or SW(PID controler), tuned by operators or logic

SC - 04Feb'13 Cryo Heaters Review

Example No1

Power Request 0-100%

Power Measured 0-100%

Power Enable

Enable Validated (needed?)

Safety Thermal Switch

SC - 04Feb'13 Cryo Heaters Review

Example No2

Power Request 0-100%

Power Measured 0-100%Power Enable

Enable Validated (needed?)

Safety Thermal Switch

Circuit breaker

SC - 04Feb'13 Cryo Heaters Review

Safety switches part1

SC - 04Feb'13 Cryo Heaters Review

Safety switches part2

Safety Thermal Switch

No reset, simple Iron-like system

SC - 04Feb'13 Cryo Heaters Review

LHC CRYOGENICS - Overall Schedule LS1

Legendw Sector warm, cryo locked -out, ready for Interco consolidations

Helium logisticsI Cryo-installations locked-out, ready for maintenance & projectsl Maintenance done, ready for cryo re-commissioning testst Helium leak tests in sectorP Pressure testF Flushing of sector

Cool-down of a sector, cryo tuning

According to master schedule V2.2 => Most likely helium leak tests with lost helium => Time available for Re-commissioning cryo refrigerators (CD delayed by R2E)

2 0 1 3 2 0 1 4Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

S12 w I 7.5m t l P F

S23 !CSCM! w I 9.5m t l P F

S34 w I 10m t l P F

S45 w I 12m t l P F

S56 w I t 6.0m P F l l

S67 w I t 5.5m l P F l

S78 w I t 6.5m l P F

S81 w I 7.5m t l P F

Key dates for cryogenics

All magnets warm in LHC: End May’13

1st magnets cold in LHC for tests: >May’14

Global bake-out of 8 sectors: >Jan’15

SC - 04Feb'13 Cryo Heaters Review

Summary

• Large variety of heaters used in the cryogenic system– Some with PID loops with active control (beam-screens)– Some to empty liquid helium or warm-up

• Few mishaps with some heaters ON and out of control !• Strong wish to have an independent ON/OFF button for

each heater (at least > 100W)

• Internal needs for summer’14, for beams early 2015