1. VELO Thermal Control System
11/22/2018
VELO Thermal Control System
VELO Meeting
7 & 8 September CERN
Bart Verlaat, Luc van Diepen, Berend Munneke & Martin Doets (NIKHEF), Frans Mul (VU)
22-Nov-18

2. VELO Thermal Control System Evaporator Section
11/22/2018
Detectors and
electronics
23 parallel cooling connections
Pressure Drop
Capillaries
VELO Thermal Control System
Evaporator Section
22-Nov-18

3. VTCS Right Evaporator 22-Nov-18 bverlaat@nikhef.nl 11/22/2018 spacers
Connection to sec. vacuum
Cooling Out
27 capillaries
Cooling Inlet
Bellow
(tertiary vacuum)
Cable & capillary channel
Tube 1,5x0,25
Manifold
22-Nov-18
Aluminum evaporator 5-part

4. Cooling block Manufacturing
11/22/2018
Cooling block Manufacturing
27 Cooling blocks have been produced!
Vacuum oven
Series mould
22-Nov-18

5. Evaporator Manufacturing
11/22/2018
Evaporator Manufacturing
Capillary bundles
Capillaries
Outlet Manifold
Inlet Manifold
22-Nov-18

6. VTCS Test setup @ NIKHEF Pump=20Hz Chiller Control CO2 Control
11/22/2018
Chiller Control
VTCS Test setup
@ NIKHEF
CO2 Control
Pump=20Hz
22-Nov-18

7. 11/22/2018
VELO Module Testing
22-Nov-18

8. VELO Module Test results
11/22/2018
VELO Module Test results
22-Nov-18

9. TEMPORARY COOLING SYSTEM / HEAT TRANSFER
11/22/2018
TEMPORARY COOLING SYSTEM / HEAT TRANSFER
Pressure Relieve Valve on
COOLING of a single cooling block
heaters
off
Switch valve
cooling
block
closed
open
gas
liquid
capillaries
Heat exchanger
manifold
Switch valve
22-Nov-18

10. TEMPORARY COOLING SYSTEM / HEAT TRANSFER
11/22/2018
TEMPORARY COOLING SYSTEM / HEAT TRANSFER
Pressure Relieve Valve
off
Heating of a single cooling block
heaters
Heat exchanger on
Switch valve
cooling
block
open
closed
gas
liquid
50ºC gas
capillaries
manifold
Switch valve
22-Nov-18

11. Cooling block installation jig (1)
frame
clamp
handle
clamp
22-Nov-18

12. Cooling block installation jig (2)
22-Nov-18

13. VTCS Tube routing in experimental area
11/22/2018
VTCS Tube routing in experimental area
Cooling plant
2 concentric assemblies for 2
separate systems (left &right)
Z=3.5m
Z=2.9m
Z=1.8.5m
Z=0.5m
Z=0m
VELO Experiment
Tube length Ca. 53m
22-Nov-18

14. Concentric tube test results:
11/22/2018
Concentric tube test results:
No unstable flow was detected.
Vertical up flow is added as static pressure to total pressure drop.
Total pressure drop is acceptable (ca. 1 bar ≈ 1.5ºC ΔT)
Concentric tube together with accumulator show a good and stabile evaporator pressure/temperature control.
81%=1620 W
22-Nov-18

15. VTCS principles: 7 6 5 R404a chiller 1 2 4 3 22-Nov-18
11/22/2018
Evaporator temperature at VELO = Accumulator temperature if pressure drop of return flow is small:
TEvaporator = T5 = f(P5) [2-phase]
P5 = P1 + dP5-1
P1 = P7 = f(T7) [2-phase]
VTCS principles:
Evaporator is always 2-phase due to heat exchange of concentric tube even if pump temperature is colder than accumulator temperature:
Tpump = T1 = TR404a
T1<T7, P1=P7 => [sub cooled]
T3 ≈T5 [Heat exchange]
T4=T3, P4<P3 [expansion, liquid to 2-phase]
Accumulator 7 6
2-phase 5
2-phase
gas
Condenser
Evaporator
R404a chiller
Restriction
Pump 1 2
Concentric tube 4
2-phase
liquid
liquid
liquid 3
2-phase
22-Nov-18

16. VTCS principles (Con’d)
11/22/2018
VTCS principles (Con’d)
Due to the combination of the accumulator and the concentric transfer tube the control of VTCS is limited to temperature control of the accumulator only. As long as the following parameters are set to be fixed:
Liquid temperature lower than to lowest required accumulator temperature. <-30ºC
Fixed massflow of CO2 such that the energy needed for pre heating the subcooled liquid is less than absorbed heat by the detector and environement.
Summarized settings:
Taccu = -25ºC Controlled
Tchiller -40ºC fixed
Massflow = 12.5 g/s fixed
22-Nov-18

17. Typical two-phase loop cycle (CO2 as tertiary coolant)
11/22/2018
Typical two-phase loop cycle (CO2 as tertiary coolant)
Liquid
A-B: Liquid pump
B-C: Pre-heating due to heat exchanger with EF
C-D: Expansion
D-E: Evaporation of CO2, heat is absorbed from heat source
E-F: Condensing in heat exchanger with B-C
F-A: Condensing to chiller B C
P [bar] D E A F
Liquid and Vapor
Enthalpy [J/g]
22-Nov-18

18. Transfer tube engineering drawing
11/22/2018
Transfer tube engineering drawing
General overview
22-Nov-18

19. Transfer tube engineering drawing
11/22/2018
Transfer tube engineering drawing
Details at VELO
22-Nov-18

20. Transfer tube engineering drawing
11/22/2018
Transfer tube engineering drawing
Details at tunnel TX84
22-Nov-18

21. Transfer tube engineering drawing
11/22/2018
Transfer tube engineering drawing
Details at RB84
22-Nov-18

22. Transfer tube engineering drawing
11/22/2018
Transfer tube engineering drawing
Construction details
22-Nov-18

23. Concentric transfer lines
11/22/2018
Concentric transfer lines
Function of the concentric transfer lines:
Keep inlet liquid CO2 sub-cooled with cooling overcapacity of return line. => Avoid vapor generation in feed line!
The outlet tube boiling temperature is ALWAYS lower than the inlet tube boiling temperature. A good thermal coupling like in a concentric option per definition keeps the inlet tube temperature lower than its local boiling temperature.
Baseline concept:
Ø6x1mm inner tube (Inlet feed) into Ø16x1mm outer tube (outlet return).
Inner and outer tubes are orbital welded together terminating into Cajon VCR- fittings.
Central 6mm tube is a soft quality stainless tube laying free in outer tube. Inner tube does not have to be centered.
Routing is optimized to have a minimum of height variation (3.5 meter maximum)
Tube assembly is insulated with 25mm Armaflex-NH and supported with Armafix supports
22-Nov-18

24. Concentric transfer line (Con’d)
11/22/2018
Concentric transfer line (Con’d)
Features:
Outer and inner tube assembly can be bend together without the risk of a buckling inner tube.
Tube conditions:
Outer annular tube is a two-phase mixture with ca. 30% vapor and 70% liquid (mass fractions) CO2.
Operational temperature range -10ºC/-40ºC
Maximum design pressure 100 bar.
Estimated environmental heat leak 300W.
Needed tooling:
Manual or Orbital welder (Swagelok Series 5 or 10) plus tube preparation tools.
Ordinary bending tool for 16mm (r=TBD)
And whatever is needed for normal pipe routing installation.
22-Nov-18

25. VTCS Transfer Tubes Protective cover 25mm Armaflex NH Isolation
11/22/2018
VTCS Transfer Tubes
Protective cover
25mm Armaflex NH Isolation
Ø14mm
Ø6mm
Ø16mm
Ø4mm
Ø65mm
Sub-cooled liquid feed line
2-phase return line
22-Nov-18

26. Rack installation path
11/22/2018
Rack installation path
Rack platform
(250 kg/m2)
A: Installation through shielding wall door on wheels.
B: Lifting through lids of platform alleys.
C: Rolling onto platform (Surface levels?) C
Lifting access
Hatch 100x120 B A
Access door
85x195
22-Nov-18

27. VTCS rack at RB-84 Envelope dimensions: Concentric tube terminal
11/22/2018
VTCS rack at RB-84
2000
1800 high
950
Envelope dimensions:
2000x950x1800
Concentric tube terminal
22-Nov-18