1. Forum on Tracking Detector Mechanics - Bonn, May 2016
The CMS PIXEL Phase 1 CO2 cooling system: Commissioning and operation of a large scale CO2 system
J. Daguin, P. Tropea, H. Postema, M. Ostrega, L. Zwalinski, B. Verlaat, P. Petagna
Forum on Tracking Detector Mechanics - Bonn, May 2016

2. Forum on Tracking Detector Mechanics - Bonn, May 2016
Summary
System specifications
System description
System performances
Conclusions
Forum on Tracking Detector Mechanics - Bonn, May 2016

3. System specifications
2-PACL based system
Operating temperature:
-20 °C to +15 °C (original request)
-23 °C to +15 °C (modified request)
Cooling power:
2 x 7.5 kW
CO2 quantities:
2 x 100 kg
2 independent cooling plants with capability of full system coverage in case of need
Service pressure (safety valves setting):
110 bar
Test pressure:
157 bar
Operating pressures:
10 bar (-40 °C) – 57 bar (+20 °C)
Max 75 bar in supply line when running warm with high DP (20 bar)
Vacuum jacketed concentric transfer lines to ensure CO2 transport up to detector connection area
Forum on Tracking Detector Mechanics - Bonn, May 2016

4. The CMS Pixel Phase 1 Upgrade CO2 cooling system
UXC55
2 manifolds (X4 near balcony)
Manifold to YB0 edge transfer lines
YB0 edge to PP1 transfer lines
PP1 to PP0 piping
PIXEL detector
USC55
2 cooling plants
2 accumulators
3 control racks
Services (power, dry air, network)
USC to UXC transfer lines
Services between USC and UXC
Forum on Tracking Detector Mechanics - Bonn, May 2016

5. Forum on Tracking Detector Mechanics - Bonn, May 2016
System safety
Construction following HSE (CERN safety unit) recommendations and safety standards (PED)
100% visual inspection + 10% X-Rays
Standard for one PED class higher
Safety file on EDMS:
CO2 detection in USC close to storage vessels
4 detection heads in USC connected to fire brigade
CO2 exhaust close to equipment
Connected to the N2 exhaust of the magnet cryo in USC
Routed to the air extraction in UXC
Forum on Tracking Detector Mechanics - Bonn, May 2016

6. Forum on Tracking Detector Mechanics - Bonn, May 2016
Cooling plants
2 identical cooling plants
Designed, built and tested at CERN (EP-DT-FS workshop)
Remote head LEWA LDE pump
Up to 160 g/s of CO2
Cold head away from the engine
Heat exchanger connected to R507 TK chiller circuit
Condenses two-phase return and subcools liquid
Two filters:
500 µm strainer at the pump suction
40 µm filter at the pump discharge
Forum on Tracking Detector Mechanics - Bonn, May 2016

7. Forum on Tracking Detector Mechanics - Bonn, May 2016
Accumulators
2 identical accumulators
Designed, built and tested at HOEFNAGEL&MEIJN (NL)
Delivered with the CE certification
140l capacity
Heat exchanger on top of the vessel to condense CO2 vapor
Lower the pressure in the system
5 x 1 kW heaters at the bottom of the vessel to vaporize liquid CO2
Rise the pressure in the system
Back-up chiller installed to lower system pressure in case of need
Forum on Tracking Detector Mechanics - Bonn, May 2016

8. Forum on Tracking Detector Mechanics - Bonn, May 2016
Manifolds
2 identical manifolds
Designed, built and tested at CERN (EP-DT-FS workshop)
8 loops with individual mass flowmeter, filter (140 µm) and regulation valve
15 kW dummy load
2 safety valves per loop
Forum on Tracking Detector Mechanics - Bonn, May 2016

9. Timeline 2014 2015 2016 Manifolds construction
Manifolds installation in UXC
Plants construction
Accumulators at CERN
Plants ans accumulators installation in USC
First CO2 circulation
Full perf tests
First maintenance
24/7 operation
2014
2015
2016
Forum on Tracking Detector Mechanics - Bonn, May 2016

10. Forum on Tracking Detector Mechanics - Bonn, May 2016
Manifolds in UXC
Forum on Tracking Detector Mechanics - Bonn, May 2016

11. Plants and Accumulators in USC
Forum on Tracking Detector Mechanics - Bonn, May 2016

12. Forum on Tracking Detector Mechanics - Bonn, May 2016
System at CMS
Forum on Tracking Detector Mechanics - Bonn, May 2016

13. Forum on Tracking Detector Mechanics - Bonn, May 2016
Transfer lines
Section 1: USC to UXC (2 x vacuum insulated concentric lines)
Installed by CRIOTEC in Fall 2014
Section 2: Manifold to top and bottom of YB0 periphery (4 x 1 common vacuum jacket for 4 concentric lines)
Installed by DEMACO in August/September 2014
Section 3: YB0 periphery to PP1 (4 x 4 vacuum jackets for 4 concentric lines)
Installed by DEMACO in February/March 2014 1 2 3 1 1 2 3
Forum on Tracking Detector Mechanics - Bonn, May 2016

14. Forum on Tracking Detector Mechanics - Bonn, May 2016
CMS system P&I (BPix)
Forum on Tracking Detector Mechanics - Bonn, May 2016

15. Forum on Tracking Detector Mechanics - Bonn, May 2016
CMS Control system
Standard CERN UNICOS control system
Control layer: 1 PLC Schneider Premium located in USC
SCADA Layer: 1 SIEMENS WinCC-OA project located in CCC
External communications
Interlocks sent to DSS (hardwire)
Process data and cooling system status sent to CMS DCS (MODBUS)
Publication of high level informations for CMS DCS (DIP)
Forum on Tracking Detector Mechanics - Bonn, May 2016

16. CMS Control system architecture
Direct MODBUS
to DSS
LHC Logging
Forum on Tracking Detector Mechanics - Bonn, May 2016

17. Cooling plant controls
Manifold
Accumulator
Manifold
CO2 Plant
Forum on Tracking Detector Mechanics - Bonn, May 2016

18. Manifold controls Bpix detector (in future)
Supply line pneumatic valves (NO)
Bypass line + dummy load
Return line pneumatic valves (NO)
Forum on Tracking Detector Mechanics - Bonn, May 2016

19. Cooling plant regulation loops
Accumulator pressure split range controller
Back-pressure controller
Superheating controller
Pump speed controller
Damper temperature controller
Forum on Tracking Detector Mechanics - Bonn, May 2016

20. Cooling plant operation
Forum on Tracking Detector Mechanics - Bonn, May 2016

21. Forum on Tracking Detector Mechanics - Bonn, May 2016
CMS System overview
UXC55 cavern
R507
BPIX PLANT
FPIX PLANT
FPIX ACCUMULATOR
BPIX ACCUMULATOR
Transfer lines
FPIX MANIFOLD
BPIX MANIFOLD
8 return
8 supply
Sector +5 and -6 PP1
Sector +14 and -15 PP1
USC55 cavern
Forum on Tracking Detector Mechanics - Bonn, May 2016

22. Start-up procedure
Start-up temperature depends on detector T (hardwired DSS signal) and user setpoint
Start-up from room temperature to °C circulation takes ≈ ½ h
Another 40 min are needed to go down to -23 °C
Pressurisation of the system
25 min
Forum on Tracking Detector Mechanics - Bonn, May 2016

23. Re-start times estimate after a stop
Operation mode
Cooling plant
Detector
Time estimate
Observation
Normal
Warm
1/2h
Need to liquify CO2 before the pump
Cold
1h – 2h
Need to rise pressure in accumulator up to detector temperature
Few minutes
CO2 conditions already fulfilled
Back-up
Forum on Tracking Detector Mechanics - Bonn, May 2016

24. Performances in normal operation
System in normal operation:
Each plant serving its own manifold
Two different temperature set points possible
Minimum temperature down to -32 °C with 7 kW
Cooling power up to 2 x 11 kW at -23 °C
FPIX system
11 kW
7 kW
-23 °C setpoint
-28 °C setpoint
-32 °C setpoint
Manifold inlet temp
Accumulator saturation temp
Pump discharge temp
Manifold outlet temp
Manifold DL heater2 power
Manifold DL heater1 power
Pump suction temp
Mass flow
Forum on Tracking Detector Mechanics - Bonn, May 2016

25. Performances in back-up operation
System in Back-up operation:
One plant serving both manifolds
Only one common temperature set points possible
In case of failure:
Both system have to be switched OFF
Restart in back-up is similar to restart in normal operation
Switch-over takes several minutes
Minimum temperature down to -27 °C with 2 x 7 kW
Cooling power up to 2 x 9 kw at -23 °C
Stop from normal operation
BPIX system
Re-start in back-up
9 kW
Manifold inlet temp
Accumulator saturation temp
Pump discharge temp
Manifold outlet temp
Manifold DL heater1 power
Pump suction temp
Mass flow
Manifold DL heater2 power
FPIX system
9 kW
-23 °C setpoint
Manifold inlet temp
Accumulator saturation temp
Manifold outlet temp
Pump discharge temp
Manifold DL heater2 power
Manifold DL heater1 power
Pump suction temp
Mass flow
Forum on Tracking Detector Mechanics - Bonn, May 2016

26. Go to warm interlock -23 °C +15 °C Cooling plant temperatures
PP1 bypasses temperatures
-23 °C
50 min
+15 °C
4 hours
Forum on Tracking Detector Mechanics - Bonn, May 2016

27. Cooling plant performances - Summary
Normal operation:
Minimum -32 °C reached with 7 kW on each plant
Maximum load of 11 kW on each plant reached at -23 °C
Maximum load of 6.5 kW on each plant reached at +15 °C
Back-up operation:
Minimum -27 °C reached with 2 x 7.5 kW
Maximum load of 2 x 9 kW reached at -23 °C
Forum on Tracking Detector Mechanics - Bonn, May 2016

28. Forum on Tracking Detector Mechanics - Bonn, May 2016
Conclusions
System installed since almost one year
System fully operational and tested
Cooling plant performances fully satisfactory and above expectations
Cooling power above specifications
But system can also work with very low load !!!
-23 °C reachable in all conditions
Back-up operation functional
Forum on Tracking Detector Mechanics - Bonn, May 2016

29. Thank you for your attention… and to all the people involved!
abdel l, andrea d’a, bart V, cedric l, Hans p, jerome n, lukasz z, maciej o, norbert F, paola T, paolo P, philippe l, robert b, steven p, and many others…
Forum on Tracking Detector Mechanics - Bonn, May 2016