first experimental tests 08/04/20141/18. first experimental tests temperature sensors 08/04/20142/18
TRANSCRIPT
First Experimental Tests
08/04/2014 1/18
First Experimental Tests
Temperature sensors
08/04/2014 2/18
Differences with the final configuration:• Pyrex • Araldite 2020 • Heaters to simulate the 10 read out chips
15 Temperature sensors:- 5 on the Silicon Sensor- 5 on the chips (“left side”)- 5 on the chips (“right side”)
First Experimental Tests
5 4 3 2 1
10 9 8 7 6
15 14 13 12 11
Baseline Device #031 + Si Heater #31112
08/04/2014 3/18
CFD Simulations2 microchannels
Pyrex ρ = 2.23 g/cm3; Cp = 0.84 kJ/kgK; k= 1.4 W/mK, s=0.525 mmAraldite 2020 ρ = 1.1 g/cm3; Cp = 1.9 kJ/kgK; k= 0.3 W/mK, s= ? (0.03 mm)Silicon (Sensor/Microch.) ρ = 2.33 g/cm3; Cp = 0.7 kJ/kgK; k= 148 W/mK, s= 0.2 mm)Cooling Fluid (FC72) ρ = 1.68 g/cm3; Cp = 1.1 kJ/kgK; k= 0.057 W/mK)
08/04/2014 4/18
HeatingEoC Pixel Matrix[W] [W]0 0
10 1.520 330 4.540 6.5
(Digital) (Analog)
Comparison between CFD Simulation and Experimental Tests
Experimental Tests
HeatingEoC Pixel Matrix[W] [W]0 0
20 340 6.5
(Digital) (Analog)
TIN = -20°CTIN = -25°CTIN = -30°C
CFD simulations
TIN = -20°CTIN = -25°CTIN = -30°C
Mass Flow = 8g/s
Nominal Power
08/04/2014 5/18
Comparison between CFD Simulation and Experimental Tests
TTstand_IN TT12-4_IN TT7-9_SENSOR TT2-14_OUT TTstand_OUT
[˚C] [°C] [°C] [°C] [°C]-13.53 -13.19 -12.94 -12.99 -13.53-12.58 -6.67 -9.90 -4.18 -9.91-12.37 -0.41 -6.93 4.33 -7.11
5 4 3 2 1
10 9 8 7 6
15 14 13 12 11
TIN = -20°C
TTstand_IN TT12-4_IN TT7-9_SENSOR TT2-14_OUT TTstand_OUT
[˚C] [°C] [°C] [°C] [°C]-17.05 -16.75 -16.45 -16.54 -17.05-17.16 -10.29 -13.41 -7.79 -14.39-17.24 -3.70 -10.29 1.15 -11.63
TTstand_IN TT12-4_IN TT7-9_SENSOR TT2-14_OUT TTstand_OUT
[˚C] [°C] [°C] [°C] [°C]-23.68 -21.03 -20.67 -20.80 -21.21-23.77 -14.52 -17.59 -11.99 -18.50-23.82 -8.29 -14.51 -3.49 -15.77
TIN = -25°C
TIN = -30°C
Experimental Tests Tstand_IN
Tstand_OUT08/04/2014 6/18
Comparison between CFD Simulation and Experimental Tests
TTstand_IN TChip_Sx TSENSOR TChip_Dx TOUT
[˚C] [°C] [°C] [°C] [°C]
TIN = -20°C TIN = -25°C TIN = -30°C CFD simulations
Chip_Sx Chip_Dx
Si Sensor
Inlet
PyrexSame inlet temperature of the Exp. Tests
HeatingEoC Pixel Matrix[W] [W]0 0
20 340 6.5
(Digital) (Analog)
08/04/2014 7/18
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5 Test at -20°C
Prova 0WProva NomProva MaxCFD 0WCFD NomCFD Max
T
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -25°C
Prova 0WProva NomProva MaxCFD 0WCFD NomCFD Max
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -30°C
Prova 0WProva NomProva MaxCFD 0WCFD NomCFD Max
T
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
-0.34 -0.60 -0.53 0.000.42 -0.28 -0.66 0.200.70 -0.41 -0.84 0.80
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
-0.30 -0.60 -0.51 0.00-0.50 -1.32 -1.60 0.13-0.80 -1.86 -2.42 0.55
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
-0.18 -0.54 -0.41 0.00-0.42 -1.30 -1.55 0.09-0.34 -1.79 -1.90 0.57
Note: coarse evaluation of the exp. tests error
T
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1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -20°C
Exp Test 0WExp Test NomExp Test MaxCFD 0WCFD NomCFD Max
T
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -25°C
Exp Test 0WExp Test NomExp Test MaxCFD 0WCFD NomCFD Max
T
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -30°C
Exp Test 0WExp Test NomExp Test MaxCFD 0WCFD NomCFD Max
T
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
0.00 0.00 0.00 0.000.75 0.31 -0.12 0.201.04 0.18 -0.30 0.80
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
0.00 0.00 0.00 0.00-0.20 -0.73 -1.09 0.13-0.50 -1.27 -1.91 0.55
DIFFERENCE
TTChip_Sx TTSENSOR TTChip_Dx TOUT
[°C] [°C] [°C] [°C]
0.00 0.00 0.00 0.00-0.24 -0.76 -1.14 0.09-0.15 -1.25 -1.49 0.57
After PT100 calibration
• Good similarity – Exp. and CFD results
• Difference especially for the 2nd chip (chip_dx) and the sensor
08/04/2014 9/18
Differences may be due to:
- Errors in the evaluation of the thickness of the araldite layers
- Variation of the mass flow rate and errors in the evaluation of the corresponding flow velocity
- Presence of heat exchange with the environment (convection and radiation) that is neglected in the model
- Variation of the chips heating power
- Inaccuracy in the temperature sensors
08/04/2014 10/18
Differences may be due to:
- Errors in the evaluation of the thickness of the araldite layers
- Variation of the mass flow rate and errors in the evaluation of the corresponding flow velocity
The simulation were repeated for different thickness and mass flow rate
negligible differences were observed
08/04/2014 11/18
Differences may be due to:
- Presence of heat exchange with the environment (convection and radiation) that is neglected in the model
- Variation of the chips heating power
Test repeated for a chosen Power-Temperature condition with convection and varying the heating power of the EoC (Digital)
1 1.5 2 2.5 3 3.5 4 4.5 5
-25
-20
-15
-10
-5
0
5
Test at -25°C
Exp Test 0WExp Test NomExp Test MaxCFD 0WCFD NomCFD Max
08/04/2014 12/18
-18
-17
-16
-15
-14
-13
-12
-11
-10
-9
-8TEST TIN = -25°C
EXP NomCFD Nom with ConvectionCFD Nom with Power increaseCFD Nom
Convection h = 8W/m2/K T = 20°C
Power increase on Chip_dx ~ 10% (22.13 W)
Influence mainly on the “2nd part” also when only convection is introduced
DifferencesTTChip_Sx TTSENSOR TTChip_Dx TOUT
No corrections -0.20 -0.73 -1.09 0.13Convection -0.04 -0.46 -0.77 0.31
Power increase -0.14 -0.66 -0.37 0.35
1. The introduction of the convection heat transfer improves the similarity with the experimental results
2. A small difference on the power supply correspond to a significant difference in temperature - an increase of 10% of power supply (22.13W instead of 20.12W) correspond to a temperature difference over the chip about one degree
08/04/2014 13/18
0 20 40 60 80 100 120
-0.02
-0.015
-0.01
-0.005
-3.46944695195361E-18
0.005
0.01
0.015
0.020W(0W/0W)
0 20 40 60 80 100 1200
5
10
15
20
Nom (20W/3W)
0 20 40 60 80 100 12049
14192429343944
Max (40W/6.5W)
Min = -0.005Max = 0.005Δ = 0.010
Min = 19.21 WMax = 21.24 WΔ = 2.03 W
Min = -0.001Max = 0.001Δ = 0.020
Min = 2.04 WMax = 4.72 WΔ = 2.68 W
Min = 39.31 WMax = 42.08 WΔ = 2.78 W
Min = 7.83 WMax = 4.49 WΔ = 3.34 W
Constant value of power supply difficult to reach
08/04/2014 14/18
08/04/2014
Temperature difference over the sensor of 1.7°C
Good uniformity
Temperature distribution over the Si Sensor
15/18
Note: values for T=-20°C and Nominal PowerSimilar temperature distribution are achieved with the other test conditions
08/04/2014
The temperature varies significantly along the section
The exact position of the temperature sensors is important
Same temperature on the bottom surface
EoC Chip sxΔT = 1.5 °C
EoC Chip dxΔT = 3.6 °C
SensorΔT=1.7°C
16/18
Note: values for T=-20°C and Nominal PowerSimilar temperature distribution are achieved with the other test conditions
Improvement suggested for the following experimental tests:
1. Higher accuracy in the temperature sensors calibration
2. Better control of the power supply
3. Note the exact position of the sensors
4. Note ambient temperature for the evaluation of the heat transfer toward the environment
5. […]
08/04/2014 17/18
08/04/2014
Future plans:
1. Setup of the CFD simulation for the real prototype
2. Both final models will be shared on the server with a reference technical note
18/18