BPix CO2 Cooling

João Noite PH-CMX-DS

BPix Layer #4 Mockup

João Noite PH-CMX-DS Slide 2

BPix Layer #4 Mockup Modification and Single-Phase ΔP at 15°C Operation

João Noite PH-CMX-DS Slide 3

Inlet CapillaryL = 1.86m ID = 0.73mm

DC-DC EvaporatorL = 2.18m ID = 1.82mm

Outlet LineL = 1.7m ID = 2.63mm

CCU2L = 0.7m ID = 1.82mm

CCU1L = 2.18m ID = 1.82mm

BPix EvaporatorL = 4.52m ID = 1.62mm

TT14

TT15

TT16

TT13

TT10

TT11

V.A- +

V.A- +

PT50

MF00PT00

TT00PT10

Inlet

Outlet

TT12

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 30

2

4

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18

20

Mass Flow [g/s]

Pre

ssur

e D

rop

[bar

]

Single Phase Pressure Drop

DP TheoryDP Experimental TT13 added for detector’s inlet HTC

measurement.

Single phase ΔP tests for test setup validation.

Comparison shows very good agreement between measured and calculated.

Test setup fully validated.

+15°C | NSB = 160W | 1.5g/s

João Noite PH-CMX-DS Slide 4

0 2 4 6 8 10 12 1415

15.8

16.6

17.4

18.2

19

Length [m]

Tem

pera

ture

[°C

]Test 5 | m = 1.50g/s | Qtotal = 160.46W | dP = 6.75Bar | dT = 2.01°C

dTexp =2.00°CdPexp =6.50bar

0 2 4 6 8 10 12 1450

51.6

53.2

54.8

56.4

58

Pre

ssur

e [B

ar]

Exp. Wall Temperature

Theory Wall TemperatureTheory CO

2 Temperature

Exp. CO2 Pressure

Theory CO2 Pressure

100 150 200 250 300 350

10

20

30

40

50

60

70

80

-40°C -30°C -20°C -10°C 0°C 10°C 20°C 30°C

Enthalpy [kJ/kg]

Pre

ssur

e [B

ar]

m = 1.50g/s | Qtotal = 160.5W | Pin = 57.69Bar | Tin = 15.05°C | dP = 6.75Bar | xout = 0.62

Experimental:dPcap =5.49bardPdet =1.01bar

------------------------Theory:dPcap =5.14bardPdet =1.53bar

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

100

200

300

400

500

600

700

800

900

1000

S

SW+SLGSW

I AD

M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 577kg/m2.s | q = 2.74kW/m2 | Psat = 52.54Bar | xout = 0.12 | xdryout = 0.70

QDC-DC =34.10W

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

200

400

600

800

1000

1200

SSW+SLG

SW

I

B

A

D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 729kg/m2.s | q = 5.50kW/m2 | Psat = 52.29Bar | xout = 0.62 | xdryout = 0.61

QDetector =126.36W

-20°C | IHL = 193W | 1.5g/s

João Noite PH-CMX-DS Slide 5

0 2 4 6 8 10 12 14-20

-18.8

-17.6

-16.4

-15.2

-14

Length [m]

Tem

pera

ture

[°C

]

Test 12 | m = 1.50g/s | Qtotal = 193.41W | dP = 7.07Bar | dT = 4.74°C

dTexp =4.93°CdPexp =7.11bar

0 2 4 6 8 10 12 1419

20.6

22.2

23.8

25.4

27

Pre

ssur

e [B

ar]

Exp. Wall Temperature

Theory Wall TemperatureTheory CO

2 Temperature

Exp. CO2 Pressure

Theory CO2 Pressure

100 150 200 250 300 350

10

20

30

40

50

60

70

80

-40°C -30°C -20°C -10°C 0°C 10°C 20°C 30°C

Enthalpy [kJ/kg]

Pre

ssur

e [B

ar]

m = 1.50g/s | Qtotal = 193.4W | Pin = 26.87Bar | Tin = -19.84°C | dP = 7.07Bar | xout = 0.47

Experimental:dPcap =4.61bardPdet =2.50bar

------------------------Theory:dPcap =4.83bardPdet =2.11bar

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

100

200

300

400

500

600

700

800

900

1000

S

SW+SLG

SW

I A

D

M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 575kg/m2.s | q = 3.69kW/m2 | Psat = 22.04Bar | xout = 0.10 | xdryout = 0.76

QDC-DC =45.99W

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

200

400

600

800

1000

1200

S

SW+SLGSW

I

B

A

D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 726kg/m2.s | q = 6.41kW/m2 | Psat = 21.80Bar | xout = 0.47 | xdryout = 0.70

QDetector =147.42W

Data Acquisition – Nominal Flow

João Noite PH-CMX-DS Slide 6

0 50 100 150 200 250 30015.8

16

16.2

16.4

16.6

16.8

17

17.2

Time [s]

Tem

pera

ture

[°C

]

Test 5 | 1.5g/s | 160.46W

TT10TT11TT12TT13TT14TT15TT16

0 50 100 150 200 250 30050

51

52

53

54

55

56

57

58

Time [s]

Pre

ssur

e [b

ar]

Test 5 | 1.5g/s | 160.46W

PT00PT10PT50

0 50 100 150 200 250 300-18.5

-18

-17.5

-17

-16.5

-16

-15.5

-15

-14.5

Time [s]

Tem

pera

ture

[°C

]

Test 12 | 1.5g/s | 193.41W

TT11TT12TT13TT14TT15TT16

0 50 100 150 200 250 30019

20

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Time [s]

Pre

ssur

e [b

ar]

Test 12 | 1.5g/s | 193.41W

PT00PT10PT50

Data Acquisition – Dryout Flow

João Noite PH-CMX-DS Slide 7

0 50 100 150 200 250 300-20

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

Time [s]

Tem

pera

ture

[°C

]

Test 14 | 0.78g/s | 193.41W

TT11TT12TT13TT14TT15TT16

0 50 100 150 200 250 30016.1

16.3

16.5

16.7

16.9

17.1

17.3

17.5

17.7

17.9

18.118.1

Time [s]

Tem

pera

ture

[°C

]

Test 7 | 1g/s | 160.46W

TT10TT11TT12TT13TT14TT15TT16

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

100

200

300

400

500

600

700

800

S

SW+SLG

SW

I A

D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 379kg/m2.s | q = 6.41kW/m2 | Psat = 21.17Bar | xout = 0.90 | xdryout = 0.79

QDetector =147.42W

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

100

200

300

400

500

600

700

800

900

1000

S

SW+SLGSW

I

B

A D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 495kg/m2.s | q = 5.50kW/m2 | Psat = 52.02Bar | xout = 0.91 | xdryout = 0.68

QDetector =126.36W

HTC Comparison -20°C vs +15°C

João Noite PH-CMX-DS Slide 8

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

5

10

15

20

25

Tsetpoint = -20°C | m = 1.5g/s | IHL = 193W

Vapor Quality

Hea

t Tra

nsfe

r Coe

ffici

ent [

kW/m

2 .°C

]

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

200

400

600

800

1000

1200

S

SW+SLGSW

I

B

A

D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 729kg/m2.s | q = 6.41kW/m2 | Psat = 19.69Bar | xout = NaN | xdryout = 0.70

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

200

400

600

800

1000

1200

SSW+SLG

SW

I

B

A

D M

Vapor Quality

Mas

s V

eloc

ity [k

g/m

2 .s]

G = 729kg/m2.s | q = 6.41kW/m2 | Psat = 50.87Bar | xout = NaN | xdryout = 0.60

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

5

10

15

20

25

Tsetpoint = +15°C | m = 1.5g/s | IHL = 193W

Vapor Quality

Hea

t Tra

nsfe

r Coe

ffici

ent [

kW/m

2 .°C

]

Layer #4 | Flow Distribution 15°C vs -20°C

João Noite PH-CMX-DS Slide 9

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.750

2

4

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18

Mass Flow [g/s]

Pre

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e D

rop

[bar

]

L#4 Mockup at 15°C - Inlet Capillary, 0.73mm ID & 1.860m Length

m = 1.51DP = 6.59

m = 1.644DP = 6.59

IHL 192WNHL 188WISB 168WNSB 160WNP 0W

mnominal=mloaded+mliquid× (n−1 )

n=1.51+1.644×3

4=1.61 g/ s

This exercise needs to be done for the remaining pixel layers

B. Verlaat, J. Noite, “Design Considerations of Long Length Evaporative CO2 Cooling Lines”, 10th IIR Gustav Lorentzen Conference on Natural Refrigerants, Delft, The Netherlands, 2012.

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.750

2

4

6

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10

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16

18

m = 1.7DP = 6.12

Mass Flow [g/s]

Pre

ssur

e D

rop

[bar

]

L#4 Mockup at -20°C - Inlet Capillary, 0.73mm ID & 1.860m Length

m = 1.326DP = 6.12

IHL 193WISB 160WNP 0W

mnominal=1.326+1.7×3

4 =1.60 g/ s

Inlet Capillary Sizing

João Noite PH-CMX-DS Slide 10

5bar 7.5bar 10bar 15barLayer Loopname ID [mm] L [m]

+Z Layer #1 L1D1PN & L1D2PF0.6 0.512 0.89 1.267 2.0210.7 1.09 1.89 2.69 4.2950.8 2.08 3.615 5.145 8.21

+Z Layer #2 L2D2PN & L2D1PF0.8 0.13 0.459 0.787 1.4470.9 0.231 0.821 1.412 2.591 0.387 1.377 2.365 4.345

+Z Layer #3

L3D2PN & L3D3PF0.8 0.754 1.645 2.538 4.3250.9 1.34 2.92 4.5 7.671 2.22 4.855 7.49 4.345

L3D4PN & L3D1PF0.8 0.771 1.665 2.559 7.70.9 1.37 2.95 4.5351 2.28 4.91 7.55

+Z Layer #4

L4D1PN & L4D4PF0.8 0.9 1.932 2.965 5.0350.9 1.591 3.42 5.25 8.911 2.64 5.68 8.72

L4D3PN & L4D2PF0.8 1.104 2.135 3.166 5.2350.9 1.95 3.78 5.61 9.271 3.24 6.28 9.33

-Z Layer #1 L1D2MN & L1D1MF0.8 0.54 1.067 1.594 2.6460.9 0.964 1.9 2.836 4.7151 1.61 3.175 4.745 7.88

-Z Layer #2 L2D1MN & L2D2MF0.8 0.474 1.107 1.742 3.010.9 0.844 1.97 3.095 5.3551 1.405 3.285 5.165 8.937

-Z Layer #3

L3D1MN & L3D4MF0.8 0.835 1.727 2.62 4.4060.9 1.48 3.06 4.645 7.811 2.46 5.1 7.735

L3D3MN & L3D2MF0.8 0.75 1.644 2.535 4.320.9 1.33 2.91 4.495 7.6651 2.21 4.85 7.48

-Z Layer #4

L4D2MN & L4D3MF0.8 1.24 2.385 3.535 5.8260.9 2.195 4.22 6.25 10.311 3.642 7.01 10.38

L4D4MN & L4D1MF0.7 0.664 1.261 1.86 3.0560.8 1.271 2.418 3.565 5.8580.9 2.25 4.28 6.31

First theoretical approximation of inlet capillary sizing for all the BPix cooling loops.

Optional 5 to 15bar total pressure drop in the circuit under nominal flow conditions.

Capillary ID and Length can be selected according to the available space at PP0.

Experimental results on Layer #4 indicate that there’s a flow variation of 20% with 6bar pressure drop across the loop.

Extra pressure drop margin needs to be kept for flow balance at the manifold’s level.

Due to manufacturing tolerances, capillary sizing must be tuned using experimental data.