The ATLAS IBL CO Cooling System - Agenda (Indico)€¦ · • Very good cooperation between the...
Transcript of The ATLAS IBL CO Cooling System - Agenda (Indico)€¦ · • Very good cooperation between the...
The ATLAS IBL CO2 Cooling
System
International Workshop on Semiconductor
Pixel Detectors for Particles and Imaging
(Pixel 2016)
(Sestri Levante, 5-9 September 2016)
On behalf of the ATLAS collaborationVERLAAT, Bart (CERN), OSTREGA, Maciej (CERN), ZWALINSKI, Lukasz (CERN), BORTOLIN, Claudio
(CERN), VOGT, Sven (MPI-Münich (DE)), GODLEWSKI, Jan (Polish Academy of Sciences (PL)), CRESPO-LOPEZ, Olivier (CERN), VAN OVERBEEK, Martijn (Nikhef), BLASZCZYK, Tomasz (CERN)
107/09/2016 B. Verlaat
ATLAS IBL: A new 1st layer
around a reduced beam pipe
2
IBL pixel sensors
IBL Carbon stave with cooling pipe
IBL Stave
IBL an extra pixel layer
Component
(32 per stave)
Power
(W/unit)
Power
(W/stave)FEI4 chip 1.12 35.84Pixel sensor (after irradiation) 0.68 21.61Stave flex 0.17 5.38Type 1 cables 0.17 5.38
Total per stave 68.21Total for 14 staves 954.94
Cooling temperature required: <-35°C
Connectiontube bundle14x 3x0.5mm
ID end plate dry volume
*
**
** *
**** * ****
* *
* **
* * * *** * **
**
*
Inner detector (TRT+SCT+Pixel)
Electromagnetic calorimeter (LAR)
Hadronic calorimeter (Tile)
Solenoid magnet
Splitter box (Concentric split and vacuumtermination)
Vacuum insulated concentric tubes (flex lines)(7x1.6x0.3mm inlet inside 4x0.5mm outlet)
Manifold box
Junction box
Vacuum insulated transfer lineMuon area sector 5
(LAR)
Beam pipe
IBL detector
The IBL cooling loops
3Manifold box in S5
PP1 connectors
Splitter box in IDEP
1 round trip = 1 loop = 31m
Flex line routing in IDEP
Evaporator tubes in staves 1.5mm
7 miniature vacuum insulated flexible cooling lines (<18mm)
Cooling plants in USA-15
4
IBL has 2 redundant CO2 systems, in case of failure it swaps transparent to the other system. Detector is minimal affected (small temperature fluctuation)
System ASystem BControls
Accumulator
Front view
Rear view
Tran
sfer line
CO2 plant commissioning
• The cooling system is commissioned over a by-pass dummy load (3kW) and with the detector attached
• The cooling system is very stable (<<1’C) over a large temperature range (from room temperature down to -35°C
Cooling plant Junction box with dummy load
11
8
9
USA15 UX15
Manifold box with detector loops
1
Liquid flow2-phase flow
2
5
5”
6
7
3 4
7”
10
-35°C set-point
20°C coolingAccumulator pressure lowering for cool down
Pressure increase for liquefying prior to start-up
Sub cooled pumped liquid( follows chiller temperature)
Saturation temperature
Liquid cooling
2-phase cooling
11
2
3, 5”, 7”(Tsat)
9 Sub cooled liquid margin for pump operation (>10 °C)
0 20 40 60 80 100 120 140 160 180-30
-20
-10
0
10
20
30
Days since 23 June 2014
Tem
pera
ture
Stave1 temperature
“Warm” commissioning
Bake-out
1st cool cold operation
Steady state tests
Detector temperature during commissioning
Junction box cooling tests (Detector by-passed)
En
d o
f co
mm
issi
on
ing
June 14 Dec. 14Simplified system schematics
Operational temperature range
8 hours
20
0
-20
-40
-60
Beam pipe bake-out• The beam pipe bake-out was a crucial event for the IBL
cooling
• The beam-pipe was heated in steps to 230⁰C, the cooling system prevented the IBL for overheating
• A 2 fault redundant operation of the cooling was established o 2 systems operated in parallel
o System back-up by a bottle battery blow system
• Results and observationso Maximum recorded sensor temperature was -8⁰C @ 230⁰C beam
pipe
o Due to twice the flow (2 systems in parallel) => ca. 4x pressure drop, most staves stayed single phase for long time.
• No serious issues during bake-out, system run without problems
6
-25.0
-20.0
-15.0
-10.0
-5.0
-50.0 0.0 50.0 100.0 150.0 200.0 250.0
Co
olin
g t
emp
erat
ure
s (°
C)
Beam pipe temperature ('C)
IBL Cooling temperatures at bake -out
-Stave01 InletStave01 OutletStave01 ModulesStave05 InletStave05 OutletStave05 ModulesStave07 InletStave07 OutletStave07 Modules Full boiling
Partly boilingLiquid cooling Stave 14 behavior
630 640 650 660 670 680 690
-20
-10
0
10
20
30
40
Time(min)
Flo
w (
g/s
), T
em
pera
ture
(`C
)
IBL-cooling blow off test with 3kW heating
FT901 Blow system flow
FT106 IBL-A flow
FT306 IBL-B flow
TT116 Junction box liquid
TT136 Junction box return (2phase)
TT117 Heater
Failure of plant B
Delivered flow
Failure of plant A Cooling temperature remains stable
Heater temperature
25 minutes of stable 3kW cooling using blow system (3kW Test was stopped to save CO2)
Blow
Sys. BSys. A
The IBL cooling heat loads
• The cooling system has to coop with several heat loads:o Detector electronics power
o Ambient heat leak in the detector
o Ambient heat leak of the system
• The detector power now is about ~30 Watt/stave (420 W total)
• The total absorbed heat load can be measured when both in and outlet of the plant are in liquid phase (occasionally present)
• The ambient heat leak in the detector, is the same order as the electrical power
• Total load for the cooling system (detector + ambient)o Current operation: 1.5 kW at low temperature
o Expected EOL: 2 kW at low temperature
o Tests have been done with 3kW dummy load
7
Total ambient heat leak
Detector power during measurements (dec 14)
Component
(32 per stave)
Power
(W/unit)
Power
(W/stave)FEI4 chip 1.12 35.84Pixel sensor (after irradiation)
0.68 21.61
Stave flex 0.17 5.38Type 1 cables 0.17 5.38
Total per stave 68.21Total for 14 staves
954.94
-35 -30 -25 -20 -15 -10 -5 0 5 10 150
100
200
300
400
500
600
700
800
900
1000
Accu setpoint temperature (°C)
Hea
t lo
ad
(W
att
)
IBL Cooling system heat loadsMeasured ambient heat (IBL=on)
Measured ambient heat (IBL=off)
CoBra ambient heat (IBL=on)
CoBra ambient heat (IBL=off)
IBL Ambient heatload fit
Total Ambient heatload
Total ambient heatload fit
IBL Detecor heat load
IBL Detector heatl load fit
Detector power
From slide 2
End of commissioning steady state
tests and comparison with simulations
(Dec. 2014)
8
0 5 10 15 20 25 30
-30
-28
-26
-24
-22
-20
-18
Ju
nctio
n B
ox
Ma
nifo
ld B
ox
Flex line IBL v olume
Inlet:
Cable temperature: -13.6±0.8 ºC / -11.2±0.9 ºC
Cable board temperature: -16.5±0.3 ºC / -10.3±0.3 ºC
Outlet:
Cable temp.: -13.6±1.4 ºC / -11.3±1.6 ºC
Cable board temp.: -16.5±0.4 ºC / -10.4±0.5 ºC
HeatLoads:
Ambient (CoBra): 446.6 W / 579.6 W
Ambient (Measured): NaN W / NaN W
Modules: 0 W / 355.4 W
Miscalaneous:
Pressure drop: 5.3 Bar / 5.5 Bar
Massf low: 18.1 g/s / 17.9 g/s
Ambient temp.: -16.5 ºC / -10.3 ºC
Exit v apor quality : 0.08 - / 0.17 -
Distance from Junction Box (m)
Tem
pera
ture
(ºC
)
IBL temperatures for set point -30ºC; Measured data and CoBra simulation results
0 1 2 3 4 5 6 7 8 9
-30
-28
-26
-24
-22
-20
-18
IBL position (m)
Tem
pera
ture
(ºC
)
dTTFoM
=3.6 ºC
dTHTC
=1.7 ºC
dTdP
=3.2 ºC
Set point=-30 ºC
TModules
=-21.5 ºC
dT
tot =
8.5
ºC
Detailed view of IBL region
CP temperatures (IBL pow er=off)
Saturation temperatures (IBL pow er=off)
Module temperatures (IBL pow er=off)
CoBra Saturation line (IBL pow er=off)
CoBra Fluid temperature (IBL pow er=off)
CoBra structure temperature (IBL pow er=off)
CoBra w all temperature (IBL pow er=off)
CP temperatures (IBL pow er=on)
Saturation temperatures (IBL pow er=on)
Module temperatures (IBL pow er=on)
CoBra Saturation line (IBL pow er=on)
CoBra Fluid temperature (IBL pow er=on)
CoBra structure temperature (IBL pow er=on)
CoBra w all temperature (IBL pow er=on)
Manifold and junction box
The IBL
Additional result numbers
Set point = -30°CAmbient heat load from previous slide included in simulations
Steady state tests (Dec. 2014)Overview of different set point temperatures
9
-35 -30 -25 -20 -15 -10 -5 0 5 10 15
0
1
2
3
4
5
6
7
8
9
10
accumultor set point temperature (°C)
IBL T
em
pera
ture
gra
die
nts
(°C
)Steady state detector temperature offsets from setpoint
Module 1 det off
Module 1 det on
Module 2 det off
Module 2 det on
Module 3 det off
Module 3 det on
Module det 4 off
Module det 4 on
Module det 5 off
Module det 5 on
Module det 6 off
Module det 6 on
Module det 7 off
Module det 7 on
Module det 8 off
Module det 8 on
JB return det off
JB return det on
MB return det off
MB return det on
CP outlet det off
CP outlet det on
CP inlet det off
CP inlet det on
MB liquid det off
MB liquid det on
JB liquid det off
JB liquid det on
Cooling pipe temperatures
Gradients increase with colder cooling temperature
Gradients due to stave conduction relatively constant
First modules show a larger and more irregular temperature offset (boiling onset issue)
Data of previous slide
Cooling performance during
operation
1007/09/2016 B. Verlaat
The cooling system is stable within 0.2 °C (<0.05 °C RMS), Detector modules within a few degrees due to power fluctuations
Cooling pipe measured stability during M9 run
Module and cooling pipe temperatures
Nick Dann
28/0
8/16
01/0
5/16
Antonio Miucci
2015**
** Please note that the shown temperatures in 2015 show values which are not yet corrected with the calibration constants defined in April 2015. As a consequence cooling pipe sensors shown are ˜1.5°C too high, Module temperatures ˜0.5°c
Operational experience since LS1
(1.5 years of operation)
• The IBL CO2 cooling system had an excellent track record: 0% downtime during physics
• Only limited interventions were needed, of which most were done during safe periods (TS, MD)
• 2 incidents during detector operationo 1 hardware failure with a successful back-up procedure
o 1 DSS interlock due to a threshold conflict in the stepper introduced for long term high temperature operation, interlock occurred during a controlled intervention
• We are getting positive feedback of the system operation and reliability by ATLAS
• Very good cooperation between the operator team (ATLAS+EN-CV) and development team (EP-DT)
1107/09/2016 B. Verlaat
Period CO2 System failure Chiller or primary cooling issue
Software modification
System test Plant recovery
DSS Interlock
Automaticswap
Maintenance intervention
Data taking
Beam 1x (Flow meter failure)
4x 5x 1x
No beam
1x (Initiated swap for maintenance followed by a trip of the 2nd system due to threshold conflict in the start-up stepper)
6x 1x
TS 5x 6x 1x 1x
MD 1x 1x 3x 3x 1x
Boiling onset problems
1207/09/2016 B. Verlaat
• Sometimes the boiling is not triggered, and a reduced cooling performance is observed (bad heat transfer)
• We are trying to understand what causes this phenomena and how we can improve it
• The non-boiling issue is annoying for the alignment due to stave bowing.
• A test set-up containing a real size stave pair including flex lines and its orientation is made in SR1 to investigate the phenomena
SR
1 L
evel
-1
SR
1 cl
ean
ro
om
DAQ rack
PC
Manifold box
Vacuum station
CO2 plant
Flex lines with support
Dummy staves
Rep
rese
nta
tiv
e h
eig
ht
dif
fere
nce
**** * ***
**
*
+ - Direct heating on pipe
Heating with silicon heaters on real stave
2657mm1412mm
2657mm
D2.2x0.1mm
D2.2x0.1mm
D1.7x0.1mm
D1.7x0.1mm D1.7x0.1mmCooling stationin SR1
Manifold box section
Spare flex lines lines
Cooling pipe
Modules
Power
1st results from SR1 test
• 1st results from SR1 show the superheated liquid in the inlet tube
• Flow reduction looks promising
• Flow reduction needs a modification in the manifold to avoid manifold evaporationo Will be tried in SR1
1307/09/2016 B. Verlaat
FlexlineIDEP
Flow direction
Inlet cooling pipe
PP
0
PP
0
PP
1
PP
1
Inlet cooling pipe
IDEPFlexline
IBL
Super heated liquid present in inlet pipe
Boiling triggered
Krzysztof Sliwa, 31-08-’16
Summary and conclusions
• The IBL CO2 cooling system was successfully commissioned in 2014.
• The cooling system has been fully operational since LS1 for 1.5 years and has performed very reliable with 0% downtime for ATLAS physics.
• The cooling system wide operational temperature range has proven to be very convenient to solve the LV-current issue.
• The high temperature stability of the cooling is very advantage for the stave bowing issue.
• The boiling onset issue is studied in a real size cooling loop mock-up in SR1.
• The IBL cooling method and operational experience has proven to be a good baseline for the ITk cooling.
1407/09/2016 B. Verlaat