First Experimental Tests 08/04/20141/18. First Experimental Tests Temperature sensors 08/04/20142/18.

First Experimental Tests

08/04/2014 1/18


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”)


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


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


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


[˚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


[˚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


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


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


1 1.5 2 2.5 3 3.5 4 4.5 5

-25

-20

-15

-10

-5

0

5

Test at -30°C


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


[°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


[°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

08/04/2014 8/18

1 1.5 2 2.5 3 3.5 4 4.5 5

-25

-20

-15

-10

-5

0

5

Test at -20°C

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


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


T

DIFFERENCE


[°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


[°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


[°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


- 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


- 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


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

First Experimental Tests 08/04/20141/18. First Experimental Tests Temperature sensors 08/04/20142/18.

Documents

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difference tt chip

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