1. Stave thermal analysis Cooling connections CO2 warm Test
LHCb - UT Upgrade
UT Mechanics + Cooling meeting
9 June 2016
Istituto Nazionale
di Fisica Nucleare
Sezione di Milano
Stave thermal analysis
Cooling connections
CO2 warm Test
Simone Coelli, Mauro Monti I.N.F.N. MILANO

2. thermal analysis update cooling connections production for test
Summary:
thermal analysis update
cooling connections production for test
CO2 WARM Test

3. thermal analysis - UPDATE
WORKING PLAN:
URGENT ANALYSIS FOR THE NEW ASIC POSITION
SYSTEMATIC STUDY ON THE DETECTOR FINAL DESIGN
URGENT ANALYSIS
PESSIMISTIC CASE:
CENTRAL STAVE
SENSOR A1.T3 (8 ASICs , MOUNTED OVER FLEXBUS CABLE)
NO SLITS IN THE CERAMIC STIFFENER
NO THERMAL VIAS IN THE HYBRID
NO CARBON FOAM EXTENSION UNDER THE SENSOR
DISTANCE ASIC-SENSOR = + 2 mm (4 mm TOTAL DISTANCE)

4. MODEL: ASICs DISPLACED + 2 mm
Note the relative positions for:
SENSOR
ASIC
COOLING PIPE
WIRE BONDING
WIRE
BONDING
SENSOR
ASIC
CARBON FOAM
COOLING PIPE

5. thermal analysis 1 - RESULTS
Sensor A1.T3-ASICs distance = 2 mm
Sensor A1.T3-ASICs distance = 4 mm
T MAX SENSOR = 6,4 °C
T MIN SENSOR = 0,7 °C
SENSOR T EXCURSION = 5,7 °C
T MAX SENSOR = 7,9 °C
T MIN SENSOR = 0,9 °C
SENSOR T EXCURSION = 7 °C
Note: Pipe external temperature set to 0 °C, local support T analysis

6. Next thermal analysis Will be followed by a SYSTEMATIC THERMAL STUDY:
USING LAST UPDATED 3D MODEL (WE NEED TO RECEIVE IT FROM RAY)
MIN-MAX ASICs-SENSOR DISTANCE
WITH AND WITHOUT SLITS IN THE CERAMIC STIFFENER
WITH AND WITHOUT THERMAL VIAS in the hybrid
Effect of CARBON FOAM EXTENSION UNDER THE SENSORS (A1.T3)
CARBON FOAM sensitivity study on thermal conductivity K = «35» W/mK

7. CO2 WARM TEST

8. COLD OPERATION ∆hl-v = 280 J/g
Attention: properties are very different for Warm CO2
COLD OPERATION
20 bar saturation pressure
- 20 °C saturation temperature
Specific Enthalpy vapour - liquid
Specific Enthalpy vapour - liquid =
∆hl-v = 280 J/g
at 20 bar saturation pressure, (~ - 20 °C saturation temperature)

9. ∆hl-v = 180 J/g => 2:3 RATIO between cold and warm conditions
WARM OPERATION
50 bar saturation pressure
~ 14 °C saturation temperature
Specific Enthalpy vapour - liquid
Specific Enthalpy vapour - liquid =
∆hl-v = 180 J/g => 2:3 RATIO between cold and warm conditions
at 50 bar saturation pressure, (~ 14 °C saturation temperature)

10. CO2 COOLING: WARM TEST / INSTALLATION CONDITIONS
DATE
STAVE “C”
FLOW DIRECTION UPWARD
INSULATION ARMAFLEX
STAVE INLET RESTRICTOR 0,254 mm
STEADY-STATE OK
TRACI P SET POINT 50 barA
SATURATION TEMP 14,3 °C WARM TEST
HEATER POWER W (0 -100% -150%)
MASS FLOW-RATE 0,88 g/s
CALCULATED X out 47 % at 100% load - 72 % at 100% load
P50bar-113W-087gs-PT.txt 10

11. CO2 warm Test Information useful for the cooling plant design
TOTAL HEATER POWER = 75 W (100 %)
MASS FLOW RATE = 0,88 g/s (Xout = 47 %)
P set = 50 barA (SAT =14,5 °C) WARM TEST
Information useful for the cooling plant design
INLET FLOW RESTRICTOR
Orifice 0,254 mm
Pressure drop = 3 bar
Similar to cold operation

12. CO2 warm Test conclusion
A cooling test was performed at set pressure 50 bar
The power is removed from che stave in stable operation
the pressure drops are similar to che cold operation test, given a similar mass flowrate near to 1 g/s of CO2.
=> confirm the possibility to operate with power on and with the box open, during the installation and test phase.

13. Cooling connections PIPE 2 mm ID / 2,5 mm OD BENDED «1 COIL»
LASER WELDED
VCR SWAGELOK CONNECTORS:
1/8 INCH
CONNECTION TO STAVE COOLING PIPE
1/4 INCH
CONNECTION TO MANIFOLD
To be confirmed, 1/8 is more compact..

14. COMPARISON OF STAVE A/B/C Next test set-up to be mounted
NEXT TEST PLANNED
COMPARISON OF STAVE A/B/C
ID 2 mm pipe with 1 coil mounted both at the inlet and the outlet
calibrated orifice at the inlet
Characterization of the stave circuit between the 2 manifolds
for the three different stave «flavours» A/B/C
Next test set-up to be mounted