Concept idea for the modular 2PACL

system for the Atlas ITK

3 June 2015

Bart Verlaat

1

CO2 cooling: the current status

• The last year lots of progress in CO2 cooling development is achieved.– 2 new systems for detector operation have been developed:

• IBL cooling system (3kW @ -35°C) => In operation• CMS pixel CO2 cooling system (15 kW@ -30°C) => under commissioning

– Many laboratory test units have been build:• 2x Traci V1, 3x Traci V2, 4x Traci V3 up to 400W• Marco 1kW• CMS-TIF prototype plant 15 kW

– New development lessons learned:• Operation at cold temperatures < -30°C • Scaling from 1kW (LHCb-Velo) to 3kW (IBL) and 15 kW (CMS)

– Scaling did not give surprises.

• Positive experience with vacuum shielded concentric lines.• Standard approach for control.• Redundancy policy

• From the current experience and the availability of standard components a scaling towards 40kW 2PACL units should be feasible

2

Atlas IBL CO2 cooling system 2-Phase Accumulator Controlled Loop

(2PACL)

Chiller CO2 Transfer line, Ca 100m

Pump

Compressor

Cooling plant

Junction box

Accumulator with integrated heating and cooling

dummy load

A

C

B

DE

Flex lines to IBL

USA15 UX15

Manifold box

-35’C cooling

20’C cooling

Accumulator pressure lowering for cool down

Pressure increase for liquefying prior to start-up

Sub cooled pumped liquid

Saturation temperature

Sub cooled liquid margin for pump operation (>10 ‘C)

Liquid cooling

2-phase cooling

Gas

Pre

ssur

e Liquid

Isothermal line

Enthalpy

C

E D

B

A

Liquid

7

2-phase(Evaporation)

Accu

AC042

LP101

ventevacuate

6

8

FT106

⅜”

EH106TT106TS106

EH101 / EH102 / EH103TT101 / TT102 / TT103TS101 / TS102 / TS103PT101 / PT102 / PT103

HX150

CO2 system A100 labels

LT142LT342

FT306

FL304

⅜”

FL306

VP05

6

50

40

12

4444

46

48

PV110

PT150/ TT150/ SC150

¼”

BD108PT108TT108

CO2 from experiment

CO2 to experiment

42

PT142

PV108

PV144

HX148

TT148BD148

SV042 SV043MV042

MV041

TT146

AV108

Freon chiller A

200

CO2 system B300 labels

10

LP101EH301 / EH302 / EH303TT301 / TT302 / TT303TS301 / TS302 / TS303PT301 / PT302 / PT303

4PT304TT304

MV306

6

8

EH306TT306TS306

BD308PT308TT308

AV308

PV308

PV310

PV344

46 TT346

HX350

HX348

LP301

Fill port

nc

nc

no

nc

no

nc

MV050

MV054MV052 MV056BD054

PT054

EV148 EV348

nc nc

50

PT350/ TT350/ SC350

SV040 MV040

SV041 BD01210

MV058

NV110

MV110 MV310nc

CV142

nc

CV342

ncnc

ncnc

nc

nc

Cold CO2 lineCold R404a lineWarm service line(Cold lines require 32mm insulation)

no

NV310

no

¼” ¼”

½”½”

½”

½” ½”

48 TT348BD348

Freon chiller B

400

MV043

PT342

BV, 03-09-2014

PT040

PT042

PT056

PRC142 controlling CV142, EH142/143(PT142 & SC150)

PRC342 controlling CV342, EH342/143(PT342 & SC350)

PT050 PT058

no

FL104

4 PT104TT104

nc

FL106

Fill port

MV106

EH142/143TT142/143TS142/143

FL042

EH342/343TT342/343TS342/343

MV012

MV039

AV012

Atlas IBL cooling system CO2 cooling plant layout

Chiller CO2 Transfer line, Ca 100m

Pump

Compressor

Cooling plant

Junction box

Accumulator with integrated heating and cooling

dummy load

A

C

B

DE

Flex lines to IBL

USA15 UX15

Manifold box

cooling water

R404A 2-stage compressor GP250

AC042

CV205

48GP246 GP248

PS250

MV202 SG202

TT248PT248

SR248

HX208

HX205

Air cooled condenser

AC210

2

HX201

HX216

HX212

MV222

MV224

MV246

MV228

MV230

4

BR234PRC234 (PT234)

12

16

38

22

26

28

30

34 36

TT202AC202

NV206

AC244HX220 /HX244CV222

SHC224(SH224)

CV238PRC244 (PT244)

TX212

PT224TT224SH224

PT244 & PT250TT244SH244

24

TT2066

8TT210 10

TT220

TT21818

20

44

14

TT24242

TT228

TT246

46

MV248

MV210

SG216

FL216

HX142/ HX230

HX226

HX348

HX150

7/8”

28

½”

⅜”

½”¼”

⅜”

½”

⅜”

½”

⅜”½”

¼”

½”½”

28

nc

nc

nc

nc

nc

no

HX206 / HX207

TX226 EV348

MV226

CV142PRC142

(PT142&SC150)

no

MV208

⅜”

SR206

½”

½”

PT234

EV208

PT142

GP250PRC250(PT250)

32

TT232

MV232

CO2 A rack

CO2 B rack

CO2 Accumulator rack

PT208TT208CV240

SHC244(SH244)

40

HX222

nc

EV206

FL212

SG212

SG210

SV210

PT202

EH250

FL244

EV212

EV207

no

Gas

Pre

ssur

e Liquid

Isothermal line

Enthalpy

C

E D

B

A

Liquid

7

2-phase(Evaporation)

Accu

Cooling plants in USA-15

5

Transfer line

CO2 cooling hardware in UX

Junction box

Vacuum system

Flex lines Manifold box

CMS Pixel Cooling System 2x 15kW @ -30 C⁰

7

FPix Plant core(USC55)

BPix Plant core(USC55)

CO2Storage

FPix Accumulator(USC55)

BPix Accumulator(USC55)

FPix

BPix

ManifoldBoxes

(UXC55)

Concentric SS pipes –insulated (vacuum

)Co

ncen

tric

SS

pipe

s –

insu

late

d (v

acuu

m)

PT PT

CMS Pixel Cooling System

8

2 Plants with accu’s

Plant interior

Transfer lines

Cooling systems for the ITK

• The ITK tracker has a total power of 180 kW (TBUpdated)• The largest CO2 2PACL plant build for CMS is 15kW • When looking to the “standard” components (Pumps, heat exchanger,

valves etc.) a system scaling up to 40kW seems possible.• The current approach to the ITK cooling is a modular approach of

several stand alone operating systems.• Redundancy is obtained by swapping a failing plant for a spare plant• Segmentation to be decided based on best segmentation logic in the

detector – 10x 20kW or 5x 40 kW??

• Roughly 2 possibilities for segmentation– Cool per sector (Take a pie of the combined detector (End-cap + barrel, but

split strip and pixel)– Cool per sub detector

• Is preferred as it makes it possible to operate each sub detector at different temperatures, eg a colder pixel detector. 9

Cooling segmentation

10

19/55

31/55

12/215/11 5/11

7/202/3 2/3

Pixel, short strop barrel, long strip barrel, end cap, services, thermal enclosure

x/y => x: power at begin without safety factor.y: Power after irradiation with safety factor

Detector segmentation or pie segmentation

PP2 segmentation2x5 locations

PP2 is the most likely space for the junction box and manifold

ITK cooling history• In the past the large upgrade cooling plant is discussed several times. Below an overview of

some relevant talks given in upgrade meetings with links.– Thermal management working group meeting - phase II system design 30 September 2009 @ CERN

• https://indico.cern.ch/conferenceDisplay.py?confId=68949• Topics: alternative concept solutions

– Atlas Upgrade week April 2011 @ Oxford• https://indico.cern.ch/contributionDisplay.py?contribId=207&sessionId=23&confId=116547• CO2 cooling activities at CERN

– Atlas Upgrade week November 2011 @ CERN• https://indico.cern.ch/materialDisplay.py?contribId=79&sessionId=35&materialId=slides&confId=108365• Cooling plant segmentation• Cavern fit check

– Atlas Upgrade week March 2012 @ SLAC• https://indico.cern.ch/contributionDisplay.py?contribId=62&sessionId=53&confId=158038• Topics: Cooling pipe sizing• Component availability

– ECFA High Luminosity LHC Experiments Workshop, 2 October @ Aix Les Bains• http://indico.cern.ch/materialDisplay.py?contribId=27&sessionId=9&materialId=slides&confId=252045• Topics: Future look on common cooling plant development

– ITK kick-off 23 January 2014 @ CERN• https://indico.cern.ch/event/288081/session/3/contribution/29/material/slides/• Topics: Wrap up of status

– ITK Cooling kick-off 11 December 2014 @ Cracow• https://indico.cern.ch/event/353053/• Topics: Kick-off of the cooling group

• Due to IBL – CO2 cooling development, the discussion of the Atlas upgrade system was stalled for a while, however most presented topics in the past are still relevant.

11

Modular 2PACL approach• A modular approach of multiple 2PACL stations is a novelty.• A 2PACL needs a dedicated filling to operate.

– Linking systems together mixes up the fluid quantity– CMS has 2 systems connected together

• Complex recovery procedures to equalize the fluid quantity before separation

– Atlas IBL has 2 plants, but 1 accumulator volume• Easy approach in mixing and separation• But accumulator cannot be taken out of service

– Best approach would be to separate the accu volume from the actuators and sensors which need maintenance

• Possible concept for a modular 2PACL approach– Have the accu volume be always part of the transfer system – Separate accu cooling, heating and sensing by housing them in a separate siphon– The modular plant contains all hardware and its volume is small

• Not much fluid mixing during a swap, therefore no complex equalization procedure needed.

– 1 spare plant is always running over a manifold connecting all units. – When a unit fails the spare can take over 1 system– The out of service unit can be repaired or swapped with another plant– Redundancy of a common primary cooling system

12

Cooling plant concept for a modular 2PACL

13

Modular plant unit with the following features:1. Local by pass for dP control 2. 2 condensers connected to 2 primary cooling systems.3. Remote head triple Lewa pump4. Contain most sensors and actuators5. Swappable for another unit

Accu unit with the following features:1. Heaters and sensors in a parallel siphons (1 for

redundant hardware)2. Thermosiphon condensers each connected to a

dedicate primary cooling system3. Able to access all active components in a separated

volume

PP2 manifold with heated by-pass

Transfer line

Modular 2PACL concept

14Plant 1Plant 2Plant 3

Spare plant(Without Accu)Runs cold over the spare manifold for direct kick-in

Spare plant manifold

USA-15

To UX15

Direct swapping in case of an event

15

Plant 1Plant 2Plant 3

Spare plantReplaces failed or serviced unit

Spare plant manifold

USA-15

To UX15

Accu as volume stays active (Belongs to the transfer line volume)Accu has its own redundancy for heating and cooling

Failed plant can be taken out of service or repaired

Quantity of cooling units

• Given the fact that we have 2x5 PP2 manifold locations:– 2x (5 systems +1 spare) = 12 active units (option 1)– 2 spares ready for direct replacement– A total of 14 units are needed

• Quantity optimization – Less units possible if segmentation is not following the 5 PP2 locations– Less units possible if A and C side PP2 manifold are connected to the same system

• Option 2: 6 active + 2 passive plants

• With a 150 kW Tracker the subunits will need cooling power in the order of:– Option 1: 15 kW– Option 2: 30 kW– Both options are okay with respect to the availability of technology (CMS = 15kW)

• 2 primary cooling plants are needed to cool all units (1 redundant)– This could be the current surface unit with a liquid brine bridging the surface and the

cavern– A local chiller is an option too, but might have space constraints

16

Conclusions

• A modular approach with x 2PACL stations is the baseline concept

• The concept seem feasible when a separation of the accu and plant is foreseen

• 1 running spare unit via a back-up manifold for immediate kick-in.

• Concept needs prototyping

17