Download - Enterprise High Desity Cooling
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ENTERPRISE HIGH PERFORMANCE COOLING
FINAL REPORT
PUMPED REFRIGERANT COOLING TECHNOLOGY
Martin Pitasi/Principle Investigator
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INDEX
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1. PROPOSED COOLING TECHNOLOGY ASSESSMENT 1.1 Candidate Cooling Technologies 1.2 Evaluation Criteria 1.3 Candidate Assessment Study
2. SYSTEM DESIGN & ANALYSIS 2.1 System Concept Cooling 2.2 Feasibility Hardware Model 2.3 R-134a Flow Prediction 2.4 Pump Performance 2.5 System Design Constraints 2.6 R-134a Saturated Liquid dT/Dp 2.7 R-134a Saturated Liquid 2.8 Orifice Selection Criteria 2.9 Goals 2.10 Orifice Hardware 2.11 Pump Performance Curve 2.12 Pump Reference Data 2.13 Pump Dimensional Drawing
3. SYSTEM RESULT 3.1 Orifice Performance Results 3.2 Results 3.3 Pump Performance Summary 3.4 COP Test Results 3.5 System Pictures
4. COLD PLATE DESIGN STRATEGY 4.1 Thermal Budget 4.2 Alpha Thermal Design Specifications 4.3 Cold Plate Design Strategy 4.4 Copper Off-Set Strip Fin 4.5 Preliminary Prototype Cold Plate No. 1 4.6 Preliminary Prototype Cold Plate No. 2 4.7 Function Prototype Cold Plat No. 1 4.8 Function Prototype Cold Plat No. 2 (Not Built)
5. COLD PLATE TESTING 5.1 Cold Plate Test Fixture Block Diagram 5.2 Test Fixture Heat Balance Study 5.3 Cold Plate Power Measurement Study 5.4 Copper Cold Plate Summary of Results 5.5 Copper Cold Plate Heat Balance 5.6 Copper Cold Plate Operating Envelope 5.7 Copper Cold Plate Superheat Study 5.8 Copper Cold Plate Test Data
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6. WIRING AND CONTROLS 6.1 Level Balancing Resistor Specs. 6.2 R-134a Flow and Pressure Safety Control Schematic 6.3 Self Heated Thermistor Specifications 6.4 Quality Sensor Schematic 6.5 Start-Up Circuit 6.6 System Wiring Diagram 6.7 Instrumentation Pin-Out Table 6.8 Instrumentation Wiring Diagram Liquid 6.9 Power Switch Wiring Diagram 6.10 Data Acquisition PCB Data
7. CALIBRATION DATA 7.1 Orifice Calibration 7.2 R-134a Cold Plate Flow 7.3 R-134a Total Flow 7.4 Pressure Transducer 7.5 Cold Plate Power Transducers 7.6 Input Power Transducer 7.7 Quality Sensor 7.8 AeroQuip Quick Disconnects
8. BOM 8.1 Mechanical ID Block Diagram 8.2 Mechanical 8.2 MBOM Continued 8.3 Electrical
9. WHITE PAPER
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1. PROPOSED COOLING TECHNOLOGY ASSESSMENT
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VAPOR COMPRESSION
Two Phase Single Phase RefrigerationTFF
Parasitic Power Consumption 340 wt 2760 wt 2133 wtCOP
Air Cooled Condenser 17 2 3.0Water Cooled Condenser 106 12 19
ControlCondensation/Dew Point N/A N/A Difficult
Ambient Air Sink Easy Easy DifficultWater Sink Easy Easy DifficultChilled Water Sink Easy Easy DifficultLoad Management None Required Easy Difficult
Reliability 50K Hrs1 50K Hrs1 12K/20K Hrs2
Cost Lowest Intermediate HighestScalability Same Same SameHot Swap/Modularity Same Same SamePackage
Size Smallest Largest IntermediateWieght Lowest Largest Intermediate
Processor InterfaceCold Plate/Evaporator UA Highest Lowest HighestRequired Area Lowest Highest Lowest
1. Limited by pump life2. Limited by compressor life
PUMPED LIQUID
1.1 Candidate Cooling Technologies a. Pumped Liquid Systems d. Heat Pipes Technology
Two Phase TF&F Circular Heat Pipes Single Phase Looped Heat Pipes
b. Vapor Compression Refrigeration Vapor Chamber c. Thermoelectric Devices e. Air Cooled Heat Sinks
1.2 Evaluation Criteria a. Parasitic Power Consumption e. Cost b. COP f. Scalability c. Control g. Hot Swap/Modularity
Condensation/Dew Point Mgmt h. Size/Weight Variable Load/no Load Operation i. Processor Interface
d. Reliability Cold Plate/Evaporator (U*A)
1.3 Candidate Assessment Study
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2. SYSTEM DESIGN & ANALYSIS
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2.1 System Concept Cooling
2.2 Feasibility Hardware Model
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2.3 R-134a Flow Prediction
44
1111
66
9911
Determine R134a Flow P = 400wts x 16 = 6400 wt. (21,843 BTU/Hr-Lb.) m= 21843/(63-41) =992.9 Lb./Hr (16.5 Lb/Min) Adjust flow to reflect the 17 th line (liquid level sensor line) Total flow required= 992.9*(17/16) = 1055 pph Assume a liquid density of R134a @ 91 F=74.3 ppcf V =1055/(74.3*0.1337) ~ 106 gph Flow/Processor = 106/17 ~ 6.2 gph
10
0
40
80
120
160
200
240
280
0 20 40 60 80 100 120 140 160 180 200
Volumetric Flow Rate (V) /gph
Pres
sure
(P) /
in w
c
DP
Max. Allowable System Resistance
PUMP PERFOMANCE DATAManufacturer….…..DTE Energy TechnologiesModel………….…...809-INDInput………………..110/120vac@60HzImpeller…………..…1.9" DiaSpeed…………..…..3450 RPMRefrigerant……...….R-134aSaturation Pres.…...102 psiaOperating Temp……91 F (33 C)
DESIGN LIMITdP= 0.0154m2
MAX ALLOWABLEdP= 0.0235m2
10
100
1000
10 100 1000
Volumetric Flow Rate (V) /gph
Pres
sure
(P)
/in
wc
PERFOMANCE DATARefrigerant……...….R-134aSaturation Pres.…...102 psiaOperating Temp……91 F (33 C)
2.4 Pump Performance
2.5 System Design Constraints
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2.6 R-134a Saturated Liquid dT/Dp
2.7 R-134a Saturated Liquid
dT/dP = 0.47P-0.69
0.000
0.004
0.008
0.012
0.016
0.020
0.024
0.028
0.032
0.036
0.040
0 20 40 60 80 100 120 140 160 180Pressure (psig)
dT/d
P (d
eg F
/in-w
c)
Tsat = 50.157Ln(Tsat) - 141.55
0
20
40
60
80
100
120
140
0 20 40 60 80 100 120 140 160 180 200
Pressure (psig)
Tem
pera
ture
(F)
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2.8 Orifice Selection Criteria
2.9 Goals
4 3 2 1 0
Liqu
id L
evel
Sens
or
6.2.
0 gp
h
6.2.
0 gp
h
6.2.
0 gp
h
6.2.
0 gp
h
6.2.
0 gp
h
6.2.
0 gp
h
6.2.
0 gp
h
400
wts
400
wts
400
wts
400
wts
400
wts
400
wts
230
in
wc
180
in
wc
17 16 15 14
6.2.
0 gp
h40
0 w
ts
6.2.
0 gp
h40
0 w
ts
PUM
P
~ ~~ ~
Quality = 30%
Sens
or L
ine
106
gph
17/ 0.047 “ Orifices
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2.10 Orifice Hardware
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2.11 Pump Performance Curve
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2.12 Pump Reference Data
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2.13 Pump Dimensional Drawing
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3. SYSTEM RESULT
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3.1 Orifice Performance Results
3.2 Results
4 3 2 1 0
220
in w
c
6.7
gph
6.6
gph
7.5
gph
7.4
gph
7.3
gph
7.2
gph
7.1
gph
400
wts
400
wts
400
wts
400
wts
400
wts
400
wts
170
in w
c17
16.
15 14 13
6.8
gph
400
wts
6.9
gph
400
wts
PUM
P
~ ~~ ~
24% < x < 27% Orifice ID = 0.047”Orifice ID = 0.052”
Sens
or L
ine
120 g
ph
Liqu
id L
evel
Sen
sor
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Input # Total Ancillary1 Htr COP Air COP LiquidPower Power Power Condenser Condenser
(wt) (wt) (wt)
1 1590 54 15362 1189 25.5 11643 1526 0 15264 1510 4.82 1505
Total 5731
AC Fans 576 192 9.1 106.1DC Fan 285 95 16.9 106.1
1 Pump, Controls, Relays, Pilot Lights, etc.
3.4 COP TEST RESULT
3.3 Pump Performance Summary
3.4 COP Test Results
0
40
80
120
160
200
240
280
0 20 40 60 80 100 120 140 160 180 200
Volumetric Flow Rate (V) /gph
Pres
sure
(P) /
in w
c
DPOP
Max. Allowable System Resistance
System Design Resistance
PUMP PERFOMANCE DATAManufacturer….…..DTE Energy TechnologiesModel………….…...809-INDInput………………..110/120vac@60HzImpeller…………..…1.9" DiaSpeed…………..…..3450 RPMRefrigerant……...….R-134aSaturation Pres.…...102 psiaOperating Temp……91 F (33 C)
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3.5 System Pictures
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4. COLD PLATE DESIGN STRATEGY
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4.1 Thermal Budget
4.2 Alpha Thermal Design Specifications
Location Temperature Temperature Thermal UADifference Resistance
(C/F) (deg C/deg F) (deg C/wt) (Btu/hr-F)Junction 85/185Junction to case 45/81 0.225Case 40/104Interface 5./9. 0.025Wall 35/95Boiling dT 2.2/4 0.011 178.7Saturation Temp 32.8/87.8Log Mean Temp. 3.5/6.3 0.0175 3467Ambient 25/77Cond. Discharge Air. 31.6/88.9
COMPAQSPECIFICATIONS
A
200 wt.200 wt.
A
SECTION A-A
200 wt
T J? 85?C
T C ? 40?C
Tj= 85 º C
Tc= 40 º C
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4.3 Cold Plate Design Strategy
Fram Discharge Pool Distributed Flow
Convoluted Fin
B B
SECTION B-B
Manifold
30% 6.2 Gp L @ 26 C
28.3 C
∆ P/ ∆ P 0 1.00
0.1 0 0.01
Qu ality (%
30 15 0
200 WT 200 WT
In Line Cu Strip 0.10”HX2.00”WX6.50”L
Supply Reservoir
Null Cavity
∆ P 0
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4.4 Copper Off-Set Strip Fin
4.5 Preliminary Prototype Cold Plate No. 1
4.6 Preliminary Prototype Cold Plate No. 2
0.10” X 2.00” X 6.50” (20 FINS/INCH)
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4.7 Function Prototype Cold Plat No. 1
4.8 Function Prototype Cold Plat No. 2 (Not Built)
ALUMINUM COLD PLATE
LID
FRAME
DISCHARGE POOL
CONVOLUTED FIN
SUPPLY RESERVOIR
MANIFOLD
NULL CAVITY
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5. COLD PLATE TESTING
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5.1 Cold Plate Test Fixture Block Diagram
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5.2 Test Fixture Heat Balance Study
DATAPM1000
CASE PH Vol Tfi Tfo Power Tht Volts Amps Thr
(psig) (gpm) (deg C) (deg C) (watts) (deg C) (VRMS) (IRMS) (deg C)1D 100.3 0.88 18.0 21.1 805.0 41.0 100.9 3.6 39.62D 101.0 0.60 18.2 21.5 710.0 38.4 92.5 3.3 36.43D 100.3 0.48 18.3 21.8 590.0 35.9 84.2 3.1 34.44D 100.3 0.30 18.9 22.4 360.0 32.2 63.9 2.3 31.65D 100.6 0.50 18.1 21.7 651.0 36.4 87.4 3.2 34.96D 99.8 0.90 17.9 21.1 840.0 41.8 101.9 3.7 44.3
RESULTSPM1000
CASE PH Mass Tfi Tfo M*Cp*dT Power Tht Power Thr
(psig) (pph) (deg C) (deg C) (wts) (watts) (deg C) (wts) (deg C)1D 100.3 438.2 64.4 69.9 706.1 805.0 105.8 364.2 103.22D 101.0 298.8 64.7 70.7 525.2 710.0 101.1 308.1 97.53D 100.3 239.0 65.0 71.2 434.2 590.0 96.6 257.6 93.94D 100.3 149.4 66.1 72.3 271.4 360.0 89.9 147.6 88.85D 100.6 249.0 64.6 71.0 466.9 651.0 97.5 275.2 94.86D 99.8 448.2 64.3 69.9 735.3 840.0 107.2 371.9 111.7
Heater 2
Heater 2 Heat
0
100
200
300
400
500
600
700
800
900
0 100 200 300 400 500 600 700 800 900
Measured Input Power / wt.
MC
p(To
-Ti)
/wt.
ACTUAL
IDEAL
No Thermal Insulation
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5.3 Cold Plate Power Measurement Study
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5.4 Copper Cold Plate Summary of Results
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5.5 Copper Cold Plate Heat Balance
COLD
HTR 3
THT
T3 = 28.3
HTR 2
THT
T
T
T
V = 6.2 gphL @ 26.6 ºC
Sub-Cooled Liquid
Saturated Vapor
HTR 2
M~61 pph Cp =0.18 WT-Hr/Lb-ºC
T2’ = 28. 3ºC
Q2=198.5 wt
Cu COLD PLATE
FINS
QL=Negligible
Cu COLD PLATE
RCU =0.017 d C/Wt
Th2 = 33.6 ºC
TS = TBD
Wall
Indium/Gallium Interface
T
26.5 ºC
28.3 ºC
Q3
R 2-S = (33.9-28.3)/198.5 = 0.028 deg. C/Wt R s-wall = 0.028-0.017 = 0.011 deg C/Wt
HTR 3
T3 = 28.3 ºC x = 30 % T2’ = 28.3 ºC
Q3=198.5 wt
Cu COLD PLATE
FINS
QL=Negligible
Cu COLD PLATE
Th3= 33.9 ºC
T
26.5 ºC
28.3 ºC
Q1 Q2
Q1 = (61*0.18*(28.3-26.6)) = 18.7 wt Q2 = (198.5-18.7) =179.8 Qave = (18.5/2) + 179.8 =189.1 wt 189.1/198.5 = (Ts-26.5)/ (28.3-26.5) = 28.2 ºC R 2-S = (33.6-TS)/198.5=0.0269 deg C/wt R s-wall = 0.027-0.017 = 0.010 deg C/Wt
33.6 ºC 33.9 ºC
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5.6 Copper Cold Plate Operating Envelope
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5.7 Copper Cold Plate Superheat Study
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5.8 Copper Cold Plate Test Data DATA
Case # Initial 101 102 103 104 105 106 107 AVEElapse Time (min) 0 30 50 70 90 110 170
Heaters 4 & 5Htr 4 Volts (VAC) 57.6 115.2 95.9 95.5 93.4 93.8 93.9 93.5 94.5
Current (AAC) 0.0 0.0 3.6 3.4 3.4 3.4 3.4 3.4 3.4
Htr 5 Volts (VAC) 58.0 115.2 95.9 95.4 93.7 94.0 94.4 93.5 94.7Current (AAC) 0.0 0.0 3.5 3.5 3.4 3.4 3.4 3.4 3.4
Water Vol (gpm) 0.0 0.0 0.9 0.8 0.85Ti (C) 22.6 23.2 18.7 18.7 18.7To (C) 21.9 22.4 21.4 21.4 21.4
Heaters 2,3,4 & 5Water otal Vol (gpm) 0.0 0.0 1.7 1.7 1.6 1.6 1.6 0.8 1.6
Ti (C) 22.6 23.2 18.4 18.4 18.4 18.4 18.4 18.7 18.4To (C) 21.9 22.4 20.8 20.7 20.8 20.8 20.8 21.4 20.8
System P1(psig) 75.0 88.5 101.0 100.0 100.0 100.0 100.0 100.0 100.2dP1(in wc) 0.0 130.0 90.0 90.0 80.0 85.0 85.0 130.0 86.0
Cold Plate Vol (gpm) 0.0 5.9 6.5 6.2 6.0 6.2 6.0 6.4 6.2dP4 (in wc) 10.0 9.0 10.0 10.0 10.0 10.0 9.7 10.5 9.9
T2 (C) 24.4 24.3 26.7 26.5 26.6 26.6 26.7 27.1 26.6T3 (C) 23.1 24.1 28.6 28.4 28.5 28.4 28.4 26.9 28.5
THTR2 (C) 22.9 24.1 34.1 34.1 33.9 33.7 33.9 27.2 33.9THTR3 (C) 22.9 26.5 C ( 79. 34.4 34.4 34.2 34.0 34.2 27.1 34.2TCP2 (C) 22.9 24.1 33.9 33.8 33.7 33.5 33.6 27.1 33.7TCP3 (C) 22.9 24.1 33.8 33.7 33.6 33.4 33.5 27.1 33.6
dP5 (in wc) 0.0 200.0 210.0 210.0 190.0 210.0 200.0 200.0 204.0VOLTS (rms) 44.0 28.3 C (82 64.4 63.9 63.2 62.8 63.2 108.0 63.5AMPS (rms) 0.0 0.0 6.4 6.4 6.3 6.3 6.3 0.0 6.3
C. Flow PM1000 Power Meter (wts) M~61 pph
Instrumentation 10.2 10.2Instrumentation+Pump 45.6 45.6
Total 1089.4 1232.0 1252.0 1214.0 1204.0 728.2
RESULTS
Water PropertiesDensity (ppcf) 62.4Cp (Btu/lb-F) 1.0
SystemHeat Balance
Htr 2 Htr 3 Htr 4 Htr 5 Htr 4&5 Htr2,3,4,&5 Htrs2,3I*E (wts) 201.4 201.4 323.6 325.1 648.7 1051.5 402.8
M(pph) 423.3 811.7 388.4MCpdT (wt) 341.0 0.0 -341.0%diff 47.4 100.0 184.7
Copper Cold PlateThermal Resistance Saturated Liquid Conditions Measred Calc. Ref. %diff
dP1 (psia) 111.80T(C) 28.5 30.1 -5.66Cp (BTU/lb-F) 0.34Density (ppcf) 74.3SG 1.19
Htr 2 Ref. Calc. (Based on Sat Temp)Vol (gph) 4.36M (pph) 43.07MCpdT (wt) 8.01Hfg(wt) 193.40Htr2 201.41T2AVE (C) 28.44
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DATA
Case # Initial 111 112 113 114 115 116 117 AVEElapse Time (min) 0 30 50 70 90 110 170
Heaters 4 & 5Htr 4 Volts (VAC) 94.31 93.60 92.98 94.20 94.90 93.60 93.92
Current (AAC) 3.35 3.38 3.17 3.39 3.42 3.37 3.34
Htr 5 Volts (VAC) 93.90 93.36 91.65 94.30 94.60 94.03 93.48Current (AAC) 3.47 3.45 3.41 3.41 3.43 3.39 3.43
Water Vol (gpm) 0.00 0.85 0.90 0.88Ti (C) 23.6 18.9 19.0 18.94To (C) 22.7 21.4 21.4 21.44
Heaters 2,3,4 & 5Water otal Vol (gpm) 1.60 1.69 1.65 1.65 1.65
Ti (C) 18.4 18.4 18.4 18.4 18.43To (C) 20.7 20.8 20.8 20.8 20.78
System P1(psig) 73.3 87.0 100.6 100.0 99.5 100.6 100.8 100.6 100.2dP1(in wc) 0.0 120.0 115.0 65.0 60.0 70.0 70.0 110.0 66.3
Cold Plate Vol (gpm) 0.0 7.5 7.0 7.5 7.0 7.7 7.6 7.2 7.5dP4 (in wc) 0.0 No Data 3.5 3.7 3.5 4.0 4.1 3.5 3.8
T2 (C) 23.5 24.1 27.1 26.6 26.5 26.7 26.7 27.1 26.6T3 (C) 23.5 23.9 26.9 28.2 28.2 28.5 28.4 26.9 28.3
THTR2 (C) 23.5 23.9 27.1 33.2 32.9 33.4 33.4 27.1 33.2THTR3 (C) 23.5 26.5 C ( 79. 27.1 33.5 33.1 33.6 33.7 27.1 33.5TCP2 (C) 23.6 24.1 27.1 33.1 32.7 33.2 33.2 27.1 33.1TCP3 (C) 23.6 24.1 27.1 32.9 32.6 33.1 33.1 27.1 32.9
dP5 (in wc) 0.0 210.0 200.0 200.0 180.0 200.0 210.0 200.0 197.5VOLTS (rms) 0.0 28.3 C (82 0.0 60.34 59.38 60.55 61.41 0.0 60.4AMPS (rms) 0.0 0.0 0.0 6.00 5.93 6.10 6.08 0.0 6.0
C. Flow PM1000 Power Meter (wts) M~61 pph
Instrumentation 10.2 10.2Instrumentation+Pump 47.1 47.1
Total 740 1178 1121 1184 1186 727
RESULTS
Water PropertiesDensity (ppcf) 62.4Cp (Btu/lb-F) 1.0
SystemHeat Balance
Htr 2 Htr 3 Htr 4 Htr 5 Htr 4&5 Htr2,3,4,&5 Htrs2,3I*E (wts) 182.1 182.1 313.7 320.2 633.9 998.0 364.2
M(pph) 435.7 820.4 384.7MCpdT (wt) 319.2 564.2 245.0%diff 49.6 43.5 32.7
Copper Cold PlateThermal Resistance Saturated Liquid Conditions Measred Calc. Ref. %diff
dP1 (psia) 112.53T(C) 28.3 30.3 -6.94Cp (BTU/lb-F) 0.34Density (ppcf) 23.5SG 0.38
Htr 2 Ref. Calc. (Based on Sat Temp)Vol (gph) 52.53M (pph) 164.18MCpdT (wt) 28.17Hfg(wt) 153.92Htr2 182.09T2AVE (C) 28.21
36
DATA
Case # Initial 121 122 123 124 125 126 127 AVEElapse Time (min) 25 50 65 80 95 110 170
Heaters 4 & 5Htr 4 Volts (VAC) 96.28 95.08 95.52 95.36 95.86 96.06 96.45 95.70
Current (AAC) 3.47 3.43 3.44 3.44 3.47 3.43 3.47 3.45
Htr 5 Volts (VAC) 97.10 95.67 95.40 95.52 95.37 95.65 96.45 95.49Current (AAC) 3.52 3.47 3.46 3.46 3.48 3.45 3.50 3.46
Water Vol (gpm) 1.00 1.06 1.03Ti (C) 19.2 19.2 19.19To (C) 21.6 21.6 21.58
Heaters 2,3,4 & 5Water otal Vol (gpm) 1.80 1.84 1.81 1.85 1.85 1.84
Ti (C) 19.1 19.1 19.1 19.1 19.1 19.07To (C) 21.1 21.1 21.1 21.1 21.1 21.11
System P1(psig) 100.3 99.6 99.8 99.4 100.3 100.6 99.4 100.0dP1(in wc) 125.0 50.0 55.0 55.0 60.0 65.0 95.0 58.8
Cold Plate Vol (gpm) 6.0 7.0 7.0 7.0 7.2 7.7 7.0 7.2dP4 (in wc) 2.0 3.5 3.8 3.5 4.0 4.4 3.2 3.9
T2 (C) 26.8 26.4 26.5 26.4 26.5 26.6 26.8 26.5T3 (C) 26.7 28.3 28.2 28.2 28.3 28.3 26.8 28.2
THTR2 (C) 26.8 33.8 33.7 33.5 33.9 34.2 26.9 33.8THTR3 (C) Ti =26.5 C ( 79. 34.2 34.2 34.1 33.8 34.3 34.5 34.1TCP2 (C) 26.8 33.6 33.4 33.4 33.7 34.1 27.0 33.6TCP3 (C) 26.8 33.4 33.3 33.3 33.6 33.8 26.9 33.5
dP5 (in wc) 210.0 190.0 190.0 185.0 200.0 205.0 180.0 195.0VOLTS (rms) To = 28.3 C (82 64.10 63.75 63.93 64.84 65.23 0.0 64.4AMPS (rms) 0.0 6.43 6.26 6.35 6.44 6.41 0.0 6.4
C. Flow M~61 pph
PM1000 Power Meter (wts)Instrumentation 0.0
Instrumentation+Pump 0.0Total 769.0 1211 1245 1249 1260 1271 758
RESULTS
Water PropertiesDensity (ppcf) 62.4Cp (Btu/lb-F) 1.0
SystemHeat Balance
Htr 2 Htr 3 Htr 4 Htr 5 Htr 4&5 Htr2,3,4,&5 Htrs2,3I*E (wts) 205.1 205.1 329.7 330.6 660.3 1070.4 410.1
M(pph) 512.9 915.0 402.1MCpdT (wt) 359.0 547.3 188.4%diff 45.6 48.9 54.1
Copper Cold PlateThermal Resistance Saturated Liquid Conditions Measred Calc. Ref. %diff
dP1 (psia) 112.60T(C) 28.2 30.3 -7.44Cp (BTU/lb-F) 0.34Density (ppcf) 74.3SG 1.19
Htr 2 Ref. Calc. (Based on Sat Temp)Vol (gph) 5.10M (pph) 50.36MCpdT (wt) 8.78Hfg(wt) 196.29Htr2 205.07
37
DATA
Case # Initial 131 132 133 134 135 136 137 AVEElapse Time (min) 25 50 65 80 95 110 170
Heaters 4 & 5Htr 4 Volts (VAC) 87.55 87.66 87.66 87.66 87.66 87.66 87.86 87.66
Current (AAC) 3.20 3.16 3.17 3.11 3.14 3.19 3.16 3.15
Htr 5 Volts (VAC) 87.32 86.98 87.78 87.88 87.30 88.10 87.88 87.61Current (AAC) 3.12 3.16 3.19 3.17 3.17 3.19 3.19 3.18
Water Vol (gpm) 0.75 0.75 0.75Ti (C) 19.3 19.2 19.25To (C) 21.8 21.8 21.81
Heaters 2,3,4 & 5Water otal Vol (gpm) 1.60 1.60 1.60 1.60 1.60 1.60
Ti (C) 19.1 19.2 19.2 19.2 18.9 19.11To (C) 21.2 21.3 21.3 21.3 21.2 21.27
System P1(psig) 90.0 100.2 100.7 100.4 100.4 100.7 100.90 100.48dP1(in wc) 120.0 120.0 65.0 70.0 70.0 65.0 70.0 78.00
Cold Plate Vol (gpm) 7.0 7.2 7.5 7.7 7.2 7.2 7.5 7.36dP4 (in wc) 4.0 4.2 4.6 4.2 4.1 4.5 4.30 4.32
T2 (C) 26.8 26.6 26.6 26.6 26.5 26.5 27.0 26.54T3 (C) 26.6 28.3 28.3 28.2 28.2 28.2 26.9 28.26
THTR2 (C) Ti =26.5 C ( 79. 33.5 33.6 33.4 33.4 33.5 27.1 33.49THTR3 (C) 26.8 33.8 33.8 33.7 33.7 33.8 27.1 33.78TCP2 (C) 26.8 33.4 33.4 33.3 33.3 33.3 27.1 33.34TCP3 (C) 26.8 33.3 33.2 33.1 33.1 33.3 27.1 33.19
dP5 (in wc) To = 28.3 C (82 195.0 205.0 200.0 200.0 200.0 200.0 200.00VOLTS (rms) 0.0 64.10 63.75 63.93 64.84 65.23 0.0 64.37AMPS (rms) C. Flow 6.43 6.26 6.35 6.44 6.41 0.0 6.38
M~61 pphPM1000 Power Meter (wts)
Instrumentation 0.0Instrumentation+Pump 44.9 44.9
Total 640.0 1108 1123 1099 1111 1116 644
RESULTS
Water PropertiesDensity (ppcf) 62.4Cp (Btu/lb-F) 1.0
SystemHeat Balance
Htr 2 Htr 3 Htr 4 Htr 5 Htr 4&5 Htr2,3,4,&5 Htrs2,3I*E (wts) 205.3 205.3 276.5 278.2 554.7 965.3 410.6
M(pph) 373.5 796.7 423.3MCpdT (wt) 279.6 503.2 223.5%diff 49.6 47.9 45.5
Copper Cold PlateThermal Resistance Saturated Liquid Conditions Measred Calc. Ref. %diff
dP1 (psia) 112.36T(C) 28.3 30.3 -7.10Cp (BTU/lb-F) 0.34Density (ppcf) 74.3SG 1.19
Htr 2 Ref. Calc. (Based on Sat Temp)Vol (gph) 5.19M (pph) 51.30MCpdT (wt) 8.74Hfg(wt) 196.53Htr2 205.28T2AVE (C) 28.22
38
6. WIRING AND CONTROLS
39
6.1 Level Balancing Resistor Specs.
40
6.2 R-134a Flow and Pressure Safety Control Schematic
CIRCUIT DESIGN
BLOCK DIAGRAM
41
6.3 Self Heated Thermistor Specifications
42
6.4 Quality Sensor Schematic
T +24 vdc
75 Ω
0.80/1.00vdc OUT
10K Ω 500 Ω
0
100 Ω
43
6.5 Start-Up Circuit
OV
ER
PR
ES
SU
RE
PR
ESS
UR
EE
ME
RG
AN
CE
OFF
SW
ITC
H11
0 V
AC N
110 VACNBUSS
110 VACLBUSS
+12
VD
C
-12
VD
C
HE
ATER
S
+12
VD
C
-12V
DC
-12V
DC PS
I*C
NT’L
FLO
WC
NT’L
-12V
DC
PUM
PC
NT’L
HTR
CNT
’L
12 V
DC
PS
24 V
DC
PS
FLO
W &
PR
ES
SU
RE
CO
NTR
OL
STA
RT C
IRCU
IT
*50
PSI <
P<1
50 P
SI
30 J
uly,
200
2
PU
MP
+ 12
VD
C
44
6.6 System Wiring Diagram
45
6.7 Instrumentation Pin-Out Table
Function Patch Panel Connector 5 Connector 1 Connector 7 Connector 4
Coolant Flow 20 3 10R-134a Flow 21 2 11CldPlt Flow 22 10 3 11Pump Disc. Pressure 23 1 8 10CldPlt Disc. Pressure 24 18 2CldPlt dP 25 11 1Input Power 26 15 -CldPlt Power 27 7 -Quality 28 17 - 9Open 29 19No Pin 4No Pin 5No Pin 6Common 8 7 7No Pin 9No Pin 10No Pin 12Liquid Level 13Liquid LevelNo Pin 16Over Press. Switch 4Over Press. Switch 5 1Ground 6 -12vdc (Common) 7 +12 vdc (Common) 9 +12vdc (Pump) 12 -24 vdc (Solinoid) 13 +24 vdc (Solinoid) 14(2 Cnt'l) +24 vdc (Solinoid) 15(15 Cnt'l) +24 vdc (Solinoid) 16(5 Cnt'l)Thermistor Quality 17 8No Pin 18Thermistor Quality 14 19110VAC N Buss 2Power Controller Pot 3 & 4
0 5 112 4
110VAC L Buss 13
46
6.8 Instrumentation Wiring Diagram Liquid
29 A
ugus
t, 20
02
LEG
3 P
OW
ER
CO
NTR
OL
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
CO
NN
1C
ON
N 5
Com
mon
+12
vdc
+24
vdc
+24
vdc
+24
vdc
+12
vdc
Common
Pat
ch P
anel
21
Pat
ch P
anel
20
Qly
Sig
Pat
ch P
anel
27
Pat
ch P
anel
22
Pat
ch P
anel
25
Pat
ch P
anel
26
Pat
ch P
anel
28
Pat
ch P
anel
24
Pat
ch P
anel
29
OV
ER
PR
ES
.S
WIT
CH
R-1
34 a
Tot
al F
low
Cld
Plt ∆P
Cld
Plt
Flow
Cld
Plt
Dis
c P
Sol
enoi
d 1
Sol
enoi
d 2
Sol
enoi
d 3
Coo
lant
Flo
w
Pum
p
Sys
Std
by
Com
mon
Qlt
Tran
s
CO
NN
7
Cntl
+24Q
ualit
y S
igna
lH
our M
eter
Cld
Plt
Flow
Qua
lity
Tran
sduc
er
1 2
3
4
5 6
7
8
9 1
0 1
1 1
2 1
3 1
4
Em
erge
ncy
Off
N
LOAD
L11
0 V
AC
Pum
p D
isc
PP
atch
Pan
el 2
3
Cld
Plt
Pw
rTr
an
Inpu
t Pw
rTr
an.
Com
mon
(Vol
ts)
(Vol
ts)(A
mps
)(A
mps
)
(Am
ps)
(Am
ps)
(Am
ps)
(Am
ps)
(Am
ps)
(Am
ps)
47
6.9 Liquid Condenser Flow Control Wiring Diagram
5 2 15
6 1 16
+24
vdc
14-2
4 vd
cCONNECTOR 1
PIN
13
PIN
15
PIN
14
WATLOW CONT’LModel 988A-22FD-JARG
Sole
noid
/102
psi
g
Sole
noid
/100
psi
g
Sole
noid
/101
psi
g
2122
110
vac
11
G
910
+12
vdc
Com
m Pum
p D
isc
Pres
sure
Tra
nsdu
cer
5/12
/200
2
48
6.10 Power Switch Wiring Diagram
6.11 Data Acquisition PCB Data
60 Hz
LOA
D
12
3
Red
White
Black
Notes:Radio Shack SN 900-7813 Red IlluminatedRocker Switch 3P SPST ON-Off/10 A 125 VAC
PCI-DAS-TC Thermocouple Board
• 16 Thermocouple Inputs• On-Board Processor• Utilizes Noise-Immune V/F Converter• J, K, E, T, R, S, B Thermocouple Types
PCI-DAS1602-16 I/O Board
• Model 16-Bit Analog Input Resolution• 330 kHz Sample Rate (PCI-DAS1602-16)• On Board Sample FIFO• Dual High Speed Analog Outputs• 24-Bits High Drive I/O (for PCI-DAS1602-16)• Fully Plug-and-Play
49
7. CALIBRATION DATA
50
7.1 Orifice Calibration
51
7.2 R-134a Cold Plate Flow
7.3 R-134a Total Flow
M = 76.6Ln(ma) - 128.1
0
10
20
30
40
50
60
70
80
90
100
1 10 100
Flow Meter Output (ma)
Mas
s Fl
ow R
ate
(pph
)
Notes:Flow Meter No.……………..2Fluid…………………....WaterTemp……………….……...70FPress………………...120 psiaOrientation…………...VerticalFlow Meter Sn…… .1391358Range………………. ..0-2 psid
M = 142.7Ln(ma) - 177.4
0
50
100
150
200
250
300
1 10 100
Flow Meter Output (ma)
Mas
s Fl
ow R
ate
(pph
)
Notes: Flow Meter No……………….3Fluid …………………... WaterTemp……… …….....…..70 FPressure………...... .120 psiaOrientation……...….HorizontalTransducer Sn……....1405480Range………………. ...0-2 psid
52
7.4 Pressure Transducer
7.5 Differential Pressure Transducers
7.6
0
40
80
120
160
200
240
280
4 8 12 16 20
Transducer Output (ma)
Pres
sure
(psi
g)
0.0
0.4
0.8
1.2
1.6
2.0
2.4
4 8 12 16 20 24
Transducer output (ma)
Pres
sure
Dro
p (p
sid)
53
7.7 Power Transducer
0
400
800
1200
1600
2000
2400
2800
3200
4 8 12 16 20 24
Transducer Output (ma)
Pow
er (w
t)
54
8. BOM
55
8.1 Mechanical ID Block Diagram
HEATER SUB-AS
Heate
Extensi
Therm
Heate
5/8 x 5/8 x 1/
(2 Places
1/4 x 1/4 x 1/
(2 Places
1/4 D Stiff
56
8.2 Mechanical ITEM NO. DESCRIPTION STATUS P/N PRICE COST
Test TFF Compaq Spares
100 1 1 0 PUMP/MOTOR IN HOUSE 001-100
110 1 1 0 MANIFOLD SUB ASS'Y TBB* 002-100 $50.00 $50.00
120 1 1 0 SEPARATOR SUB ASS'Y TBB* 003-101 $100.00 $100.00
130 1 1 0 CONDENSER/SUB ASS'Y IN HOUSE 004-101 $0.00 $0.00
140 1 1 0 RECEIVER SUB ASS'Y TBB* 005-100
141 1 1 24"L X 3"D COPPER TUBE TBB* 005-101 $0.00 $0.00
142 2 2 3" X 3' X 5/8" COPPER TEE TBB* 005-102 $0.00 $0.00
143 2 2 3" D END CAPS TBB* 005-103 $0.00 $0.00
150 0 1 0 SAFETY LINE TBB* 006-000
151 0 0 1 0 5/8 PRESSURE RELIEF VALVE PURCHASE 006-101 $54.64 $54.64
160 3 16 16 DISTRIBUTION LINES TBB* 006-202
161 0 32 32 4 1/4" BALL VALVES PURCHASE 006-303 $22.22 $1,422.08
162 0 16 16 4 1/4" TEE" ACCESS VALVE PURCHASE 006-404
163 3 16 16 3 1/4" SIGHT GLASSES PURCHASE 006-505 $10.38 $394.44
170 3 16 16 0 HEATER SUB ASS'Y TBB* 007-100
171 32 32 1/4" X 1/4" X 1/4" TEES PURCHASE 007-101 $1.25 $125.00
172 32 32 5/8" X 5/8" X 1/4" TEES PURCHASE 007-102 $2.00 $200.00
173 16 16 5/8" X 3 " TUBES PURCHASE 007-103 $0.00 $0.00
174 16 16 5/8" X 1/4" FPT ADAPTERS COMPAQ 007-104 $0.00 $0.00
177 32 32 5/8" D Heater Extension TBB* 007-107 $1.13 $36.00
178 32 32 1/4"D X 2.5 " Stiffener TBB* 007-108 $0.24 $7.60
180 3 16 16 3 ORIFICE SUB ASS'Y TBB 008-100
181 16 16 1/4" ORIFICES PURCHASE 008-101 $4.50 $72.00
181 16 16 1/4" ORIFICE ADAPTERS TBB 008-102 $0.92 $14.72
190 NA 1 NA FLOW METER SUB ASS'Y TBB* 009-000
192 6 6 3/8 ' X 3/8" X 1/4" TEES TBB* 009-002 $0.00 $0.00
193 2 2 1/4 Metering Valves PURCHASE 009-003 $47.60 $95.20
193 2 2 FLOW METERS PURCHASE 009-003 $265.00 $530.00
200 NA TUBE + FITTINGS + VALVES220 2 2 5/8' FLEX LINE SUB ASS'Y IN HOUSE 010-001 $0.00 $0.00
221 36' 36' 1/4" TUBING PURCHASE 010-002 $1.23 $44.16
222 6' 6' 3/8 " TUBING PURCHASE 010-003 $1.81 $10.87
223 12' 12' 5/8 " D TUBING IN HOUSE 010-004 $0.00 $0.00
224 6' 6' 2" TUBING IN HOUSE 010-005 $0.00 $0.00
225 2 2 2" CAPS PURCHASE 010-006
226 1 1 2"X2"X5/6" TEE'S PURCHASE 010-007
228 1 1 5/8" BALL VALVE IN HOUSE 010-009 $0.00 $0.00
229 5 5 3/8" BALL VALVE IN HOUSE 010-010 $49.80 $99.60
230 0 1 0 0 RACK ASSEMBLY231 0 1 0 0 Frame PURCHASE 011-001 $269.46 $269.46
232 0 1 0 0 Panel PURCHASE 011-002 $110.86 $110.86
233 0 2 0 0 Side 55 PURCHASE 011-003 $95.42 $190.84
234 0 1 0 0 Top 18 PURCHASE 011-004 $58.27 $58.27
235 0 1 0 0 P-B166 100 mm base PURCHASE 011-005 $95.31 $95.31
236 0 1 0 0 Casters PURCHASE 011-006 $67.99 $67.99
QTY
57
8.3 MBOM Continued
237 1pk PANEL NUTS PURCHASE 011-007
240 HEATERS241 16 4 500 WT/120 VOLT/ 4 " L PURCHASE 007-109 $28.04 $560.80
242 16 2 400 WT/120 VOLT/ 4 " L PURCHASE 007-110 $28.10 $505.80
243 4 500 WT/120 VOLT/ 4 " L WITH J TC PURCHASE 007-111 $76.50 $306.00 Q y g $50 00
250 PRESSURE SWITCH
251 1 1 PURCHASE 012-001 $47.00 $94.00
260 MISC.
261 120 FRONT FERRULS PURCHASE 013-001 $0.26 $31.20
262 1 ORIFICES PURCHASE 014-000 $4.95 $4.95
263 1 ORIFICES PURCHASE 014-001 $4.95 $4.95
264 3 30# CANISTERS OF R-134A PURCHASE 015-000 $125.00 $375.00
265 20 1/4" SAE FLARE NUTS PURCHASE 015-001 $0.34 $6.80
266 20 1/4" FLARE SWEAT ADAPTERS PURCHASE 015-002 $0.61 $12.20
267 20 1/4" 90 DEG. ELLS PURCHASE 015-003 $1.23 $24.60
268 1 HAND BLIND RIVIT TOOL PURCHASE 015-004 $45.50 $45.50
269 2 BX BLIND RIVITS PURCHASE 015-005 $11.80 $23.60
270 1 BX BLIND RIVITS PURCHASE 015-006 $11.95 $11.95
271 1 BX BLIND RIVITS PURCHASE 015-007 $28.49 $28.49
272 1 1/4"D X 72" L SS ROD PURCHASE 015-008 $15.80 $15.80
273 2 TOOLING & CONSTRUCTION BALLS PURCHASE 015-009 $12.10 $24.20
274 6 7/32 " DIA. BRASS ROD PURCHASE 015-010 $0.55 $3.31
275 4 1/8 " DRILL BITS PURCHASE 015-011 $0.84 $3.36
276 1 7/32" D TRANSFER PUNCH PURCHASE 015-012 $1.59 $1.59
277 2 7/32 " DRILL BITS PURCHASE 015-013 $1.42 $2.84
278 2 1/4' COUNTER BORE PURCHASE 015-014 $5.77 $11.54
279 2 CARBIDE DEBURING BIT PURCHASE 015-015 $7.69 $15.38
280 6 1/4" BRASS BARE PURCHASE 015-016 $0.63 $3.78
281 1 1/16"TX2 1/2" W X 24"L C-1018 STELL PURCHASE 015-017 $18.55
282 1 1" X 1" X 1" AL CHANNEL 1/8' WALL PURCHASE 015-018 $18.40
283 1 3/4" X 3/4" X 6 FT BRASS BAR PURCHASE 015-019 $35.04
284 2 1/16" T X 1/2"W X 6' L BRASS BAR PURCHASE 015-020 $4.73 $9.46
285 4 1" X 1" X 8'L AL ANGLE 1/8" WALL PURCHASE 015-021 $14.48 $57.92$ ,
* TBB TO BE BUILT
58
8.4 EBOM
ITEM NO. QTY DESCRIPTION STATUS P/N
500 4 AC POWER SUPPLY SYSTEM IN HOUSE 001-100501 4 20 AMP CIRCUIT BREAKER TBB* 001-101502 4 140/20 AMP VARIAC IN HOUSE 001-102503 4 20 AMP CONTACTERS IN HOUSE 001-103
510 4 HTR BANK TBB* 002-100511 16 5 AMP FUSS HOUSINGS TBB* 002-101512 16 5 AMP FUSSES TBB* 002-102513 16 0.5 kW /120 VAC CARTRIDGE HTS TBB* 002-103514 16 MECH. THERMOSTATS TBB* 002-104515 16 5 AMP TOGGLE SWITCHE/LIGHTS TBB* 002-105
520 4 POWER INSTRUMENTATION TBB* 003-100521 4 20 AMP CONTACTERS PURCHASE 003-101522 1 WATT METER IN HOUSE 003-102523 1 4 POSITION ROTARY SWITCH IN HOUSE 003-103524 1 2 POSITION ON/OFF SWITCH IN HOUSE 003-104525 1 110/120 VAC TO 48 VDC PWR SUPPLY IN HOUSE 003-105
530 1 PRESSURE CONTROL SYSTEM/ALARM TBB* 004-100531 1 CONDENSER FAN/MOTOR IN HOUSE 004-101532 1 IRON-CONSTANTAN TC ASSEMBLY PURCHASE 004-102533 1 TEMP/PRESSURE CNT'L PURCHASE 004-103534 1 ? AMP CONTACTER PURCHASE 004-104535 2 LIGHT/NOISE ALARMS PURCHASE 004-105
540 1 LIQUID LEVEL CONTROL TBB* 005-000541 1 LIQUID LEVEL CONTROL SENSOR PURCHASE 005-001542 1 100 AMP CONTACTER PURCHASE 005-002543 1 ? AMP CONTROLLER PURCHASE 005-003
550 1 AMBIENT ALARM + SAFETY TBB* 006-000551 1 AMBIENT TEMP. SENSOR PURCHASE 006-001552 1 100 AMP CONTACTER PURCHASE 006-002553 1 ? AMP CONTROLLER PURCHASE 006-003554 1 ALARM (VISUAL+NOISE) PURCHASE 006-004
560 MISC. SWITCHES 007-000561 1 FAILSAFE PRES. SWITCH PURCHASE 007-001562 1 HIGH PRES. SAFETY SWITCH PURCHASE 007-002563 1 SYSTEM POWER SWITCH PURCHASE 007-003564 1 START/STOP SWITCH PURCHASE 007-004
570 MISC. HARDWARE 008-000571 TBD NEMA BOXES PURCHASE572 TBD WIRE PURCHASE573 TBD WIRE NUTS PURCHASE574 TBD ETC PURCHASE
59
9. WHITE PAPER
60
To: Joe Marsala From: Marty Pitasi Subject: Pumped Two-Phase Cooling Paper Date: 18 December, 2008 References: a. Refrigerant 134a (R-134a), “2001 ASHRAE Handbook of Fundamentals” pages 20.16 &
20.17 b. Pump curve, “hy/save 809-IND Performance Curve” for 60 HZ, 3450 PRM, 1.95”D impeller c. Quick disconnects AeroQuip Corporation “P/N AE71406B, Coupling Half, Modular, and P/N
AE71572B, Coupling Half, Rack.” d. Pump Reliability, Hy-Save Energy Conservation Technologies letter, Subject “Refrigerant
Pump Reliability,” date August 23,2001 Enclosures: 1. R-134a PUMPED (2Φ) COOLING SYSTEM FLOW DESIGN 2. PROTOTYPE COLD PLATE FLOW CONCEPT 3. PROPOSED COLD PLATE 4. SYSTEM PERFORMANCE 5. HARDWARE INTERGRATION 6. COLDPLATE PERFORMANCE SUMMARY 1. Summary A new and versatile high performance, isothermal-cooling design, currently capable of cooling 6.4 kW at 33°C (91°F) with a COP of 100 is discussed. The system is a pumped liquid two-phase (2Φ) cooling design that uses a 1/20 HP motor-hermetic pump prime mover. The fluid is refrigerant 134a (R-134a), an ecologically friendly refrigerant used in car air conditioners. The design consists of pumping R-134a through a series of metered distribution lines that delivers refrigerant to heat exchangers/cold plates (evaporators). Heat is absorbed by the refrigerant changing it from a liquid to a vapor. The vapor is then converted back to a liquid via an air or liquid cooled condenser. This technique is scalable. A simplified 0.5kw system was built as a demo. Specifics of the design are similar to those discussed in the paper. 2. Introduction In anticipation of a 200wt. ALPHA processor (or equivalent) for the next generation of Enterprise Computer, Compaq Computer’s Alpha Server Division surveyed all available cooling technology. Their goal was to establish a cooling strategy that would be applicable for future system and component cooling needs. As a result of the survey a pumped liquid 2Φ cooling system was identified and developed. This system is able to meet all design constraints including envelope size, cabinet integration, reliability, parasitic power limits, cooling demands, and control issues. The proof of concept flow diagram (enclosure 1) shows the R-134a fluid being pumped into a distribution manifold. Flow metering orifices uniformly distribute the R-134a into 16 parallel ¼” D lines. Custom 400 wt heaters simulate 2 x 200 wt processor packages converting the liquid to vapor. To enhance the system performance the vapor is discharged into a vapor-liquid separator where gravity causes the saturated liquid to displace the vapor to the condenser. Sub-cooled fluid flowing from the condenser mixes with the saturated fluid prior to the pump. To prevent heat exchanger burn out, orifices are sized to deliver flow at rates that guarantee a vapor quality not to exceed 30%. Enclosure 1 shows an additional line. Line 17 is at the top of the system and is used to monitor the refrigerant charge. The thermal budget limited the heat exchanger‘s case-to-sink thermal resistance to 0.011°C/wt. Flow analysis of the problem showed that an inline convoluted strip fin design with a pitch of 10
61
fins/ inch and measuring 0.10”H x 2.00”W would meet the 0.011°C/wt requirement. The subsequent design shown in enclosure 2 depicts the heat exchanger flow components. Flow enters the heat exchange via a ¼” D line and pools behind a distribution manifold, then uniformly flows across the fins into a vapor reservoir prior to discharge via 1/2” D line. To ensure a uniform flow across the fins, therefore uniform cooling, and the manifold flow loss is designed as the primary loss exceeding the fin, fluid expansion, and entrance and exit effect. The heat exchanger accommodates 2/200wt processor packages approximately 2” W x 2” D, resulting in an overall proof-of-concept cold plate size of approximately 2 7/8” W x 8 5/8’” L x 5/8” H. A sketch of the proposed final deign is shown in enclosure 3. Briefly, the two goals are to build and demonstrate: (1) a proof-of-concept pumped liquid, two-phase (2Φ) cooling system capable of uniformly cooling 16/400 wt (6.4kw.) loads at temperatures below 33°C, and (2) a heat exchanger with a sink-to-case thermal resistance ≤ 0.011°C/wt. 3. Results A diagram of the proof-of-concept hardware is shown in enclosure 1. As described earlier the primary system components of motor-pump, distribution manifold, orifices, vapor/liquid separator, and condenser are clearly visible. Other support hardware such as reservoir, liquid level sensor, and sight glasses are also shown. Specifics regarding the system design point were extracted from the R-134a phase diagram (Reference a) and the pump performance curve (Reference b). The vapor enthalpy (hfg) for 30% quality and 33°C (91°F) produces approximately 6.4 wt-Hr/Lb. Combining this value with an overall load of 6.4kw and adjusting for the 17th leg results in a total flow requirement of 100 gph. Using the pump performance curve, figure 1 of enclosure 4, a maximum allowable design pressure of 7.6 psi was extracted and used to determine the orifice sizes. As shown in figure 2 of enclosure 4, a minimum of 5.9 gph of R-134a at 33°C is required for each leg. However, in practice with off-the-shelf orifices, the flows ranged from 6.6 to 7.5 gph, thus, resulting in a maximum vapor quality of 27%. The assembled system integrated into Compaq GS-320 19” cabinet is shown in enclosure 5. Note both air and liquid condensers included. Coefficient-of-Performance (COP) test results range from 17 to 100+
4. Discussion of Results
for air and liquid cooled condenser, respectively. To determine the thermal performance of the heat exchanger a heat balance was performed. Two 2” x2” film heaters simulate the package envelope, dissipating 200 wt each. They were mounted to the cold plate via an indium/gallium amalgam interface material. Thermal insulation was placed over the heaters to eliminates loses. Input power, flow, and critical temperatures were measured. The resulting maximum heat transfer coefficient extrapolated from the data was 0.011°C/wt. Enclosure 6 summarizes the data used to evaluate the analysis.
Test data from twenty-one (21) separate tests were used to statistically determine the heat exchanger’s sink-to-case thermal resistance. Values ranged from of 0.009 °C/wt to 0.011°C/wt. Enclosure 5 shows the proof-of-concept system integrated into a typical Enterprise cabinet. The design requires approximately 5% of the cabinet volume and doesn’t encroach into the sensitive electronics envelope. Not show, is the design strategy that allows for quickly hot swapping a board using quick disconnects (reference c) By operating the system at 33 °C ambient, condensation issues are avoided. Any leakage takes the form of a non-contaminating gas. The 1/20 HP motor-hermetic pump moves 6.4 kW at 33 °C and has a documented minimum MTBS of 50,000 hours (reference d). Control is inherent in the
62
design. R-134a operating temperatures are managed by the condenser performance, and load variability is managed at the receiver/separator. Coefficient of performance (COP) values range from 17 to 100+ for air and liquid cooled condensers, respectively. The only difference between the two is the fan power needed for the air-cooled condenser.
63
64
65
66
67