MECHANISM ENABLING

RETROFIT FOR COOLING OF

DATA CENTER COMPONENTS

Greg Meyer

Chenell York

Matthew Kaminski

Naji Alibeji

Advisor: Dr. Mark Kimber

AGENDA

Background

Thermal Analysis

Design

Construction

Testing

Results/Conclusion

Future Work

DATA CENTER BACKGROUND

• Data Centers house server trays for computer

systems and other supporting infrastructure

GLOBAL IMPACT

61 billion kilowatt-hours annually

Similar to amount of electricity consumed by 5.8 million average U.S. households

1.5 percent of the country's entire electricity consumption.

4

SCOPE OF PROJECT

Demonstrate feasibility of retrofitting a data center with liquid-cooled thermal management solution

5

Factory Installed Air-Cooled

Solution

Liquid-Cooled Retrofit

SERVER BOARD LAYOUT

Foxconn G41MXE Series

Motherboard

1. Core 2 Duo Processor

Max temp. = 72°C

TDP = 65 W

2. South Bridge Intel ICH7

Max temp. = 99°C

TDP = 3.3 W

3. North Bridge Intel G41

Max temp. = 102°C

TDP = 25 W

*TDP= Thermal Design Power

12

3

𝐻

𝑊𝑐ℎ

𝐻𝑐ℎ

𝑊𝑓 𝑇𝑐ℎ𝑇𝑗

L

W

t

MICROCHANNEL HEAT SINK

Arrangement of channels and fins which are used to increase the area available for heat transfer from the component to the fluid

Assuming:

• Hydro-dynamically Fully Developed

• Thermally Fully Developed

• Fin efficiency = 100%

• All heat is conducted through channel

base and fins

OPTIMIZATION

The best heat transfer performance requires the

smallest hydraulic diameter

A smaller hydraulic diameter increases the pressure

drop and pumping power

This competition will yield an optimal value

CALCULATING FLOW RATE

Pump Curve

Δ𝑃 = 𝑃0 −𝑃0 𝑉

𝑉0

System Curve

Δ𝑃 =32 𝑉μ

ℎ∗ (

𝐿1

𝑊𝑐ℎ1𝐷12 +

𝐿2

𝑊𝑐ℎ2𝐷22 +

𝐿3

𝑊𝑐ℎ3𝐷32 )

JUNCTION TEMPERATURE CALCULATION

• Convert 𝑉 to 𝑚 and substitute 𝑚 into equation below

𝑇𝑗𝑖 =𝑇𝐷𝑃𝑖

𝑇𝐷𝑃𝑖 ∗ 𝑁𝑠𝑡𝑎𝑟_𝑡𝑜𝑡𝑎𝑙 ∗ ℎ𝑖 ∗ 𝐴𝑤𝑒𝑡𝑡𝑒𝑑𝑖+𝑇𝐷𝑃𝑖 ∗ 𝑡

𝑘 ∗ 𝐴𝑐+

𝑇𝐷𝑃𝑖 𝑚 ∗ 𝑐𝑝

+ 𝑇𝑤𝑎𝑡𝑒𝑟𝑖𝑛

Where,

𝑇𝑗𝑖 = Junction Temperature of chip i

𝑇𝐷𝑃𝑖 = Thermal Design Power of chip i

𝑁𝑠𝑡𝑎𝑟_𝑡𝑜𝑡𝑎𝑙 = Expression relating number of channels to TDP

ℎ𝑖 = Convective heat transfer coefficient for water through heat sink i

𝐴𝑤𝑒𝑡𝑡𝑒𝑑𝑖= Wetted area of a channel in heat sink i

𝑡 = Thickness of copper base

𝑘 = Thermal conductivity of copper

𝐴𝑐 = Area of component i

𝑚 = Total mass flow rate through all heat sinks

𝑐𝑝 = Specific heat of water

𝑇𝑤𝑎𝑡𝑒𝑟𝑖𝑛 = Temperature of water entering heat sink i

DETERMINING RATIO OF CHANNEL NUMBER

TO THERMAL DESIGN POWER

• Plot 𝑇𝑗1, 𝑇𝑗2, 𝑇𝑗3vs. Nstar_total

• Find Nstar_total that corresponds to hottest of the minimum

junction temperatures

0.41

0.45

0.40

MATLAB GUI

DESIGN CONSIDERATIONS

Challenge: This product is intended to be a retrofit so it must be

designed around existing server boards.

Assumption: We based our design around a server board accessible

to us, but it should still fit others.

FUNCTIONAL REQUIREMENTS

Must dissipate required heat and keep junction

temperature below limit for all components requiring

cooling

Must be universal for any server board

Must apply required static load

Must fit in confined space

Must be waterproof

FINAL DESIGN

Spring

Header Microchannel

Heat Sink

Locator

Bracket

Elbow

Fitting

Lid

Dowel Pin

USING 𝑖PARTS AND 𝑖ASSEMBLIES

Through the use of parametric tables, iParts

and iAssemblies allow quick modifications to

parts and assemblies. Each row in the table will

correspond to a new part with its own part

number and altered features.

METHOD OF FABRICATION

Part: Microchannel Base

Material: Machinable

Copper

Method: CNC Machine

Notes: purchased a .026”

bit to machine

microchannels

Part: Headers, Lid, and

Bracket

Material: Acrylic

Method: CNC Machine

ASSEMBLY

2-56 UNC bolts are used to mount the

lid and headers to the micro channel

base

Silicon is used to seal the mating faces

Teflon tape is used on the fitting

threads to keep it sealed

Dowel pins were press fitted into the

locator bracket plate

Challenge: Sealing the cooling block.

BILL OF MATERIALS

Part Description Part # Vendor Unit Price

($)

QTY

6" X 6" ultra-conductive Copper 89675K15 McMaster 62.94 1

Clear Cast Acrylic Slat 8560K191 McMaster 7.04 1

.026" End Mill, square end, long flute 8915A28 McMaster 23.61 3

302 SS precision Compression Spring 9435K82 McMaster 7.36 1 pack (5)

10-32 UNF thread elbow barb fitting KL230-1 Value

Plastics

Sample 2 packs

(5)

Corrosion Resistant Dowel Pin, type

316 SS

97395A453 McMaster 4.77 2 packs

(5)

Flexible PVC tubing 1/8" inner

diameter

5233K52 McMaster 0.25 1ft

General Purpose double sided Tape 77185A21 McMaster 15.44 1

Adapter fitting, Tube to male threaded

pipe

2974k124 McMaster 5.26 1 pack

(10)

Threading Adapter, NPT 1/8 M to G 1/4

F

ADT-N18M-

G14F

Koolance 2.17 5

TOTAL: $195.51

TESTING

RESULTS/DISCUSSION

RESULTS/DISCUSSION

Thermal Resistance for CPU

Cooling Block

Thermal Resistance for South

Bridge Cooling Block

CONCLUSIONS

Goal: Design a mechanism that enables a retrofit

for cooling of data center components

The design was successful in that it provided a

solution for retrofitting current air cooled server

boards with a universal water cooled mechanism.

Testing of the cooling blocks yielded insufficient

results.

North Bridge cooling block not tested

Thermal Resistance too high for tested cooling blocks

RECOMMENDATIONS FOR FUTURE WORK

Redesign to allow for less parts/mating faces in the

assembly

Less hardware

Less machining time

Creates a more effective seal

Improvement for mounting mechanism

More sophisticated GUI

Link between GUI results and Solid Model

Additional testing to evaluate cooling block

performance

REFERENCES

Scheihing, DOE Data Center Efficiency Program, 2008.

Intel® I/O Controller Hub 7 (ICH7) Datasheet. Thermal Design Guidelines. Document 307015-001. Initial Release. April 2005. Intel. 4 April 2012. http://www.intel.com/content/www/us/en/io/intel-io-controller-hub-7-guide.html

Intel® Core™2 Extreme Quad-Core Processor QX6000Δ Sequence and Intel® Core™2 Quad Processor

Q6000Δ Sequence Datasheet. Document 315592-005. Rev. 5. August 2007. Intel. 4 April 2012. http://download.intel.com/design/processor/datashts/31559205.pdf

Intel® G45, G41, Q45, Q35 and Q965 Chipsets for Embedded Applications Datasheet. Thermal Design Guide. Document 415360. Revision 1.5. February 2009. Intel. 4 April 2012. http://download.intel.com/embedded/chipsets/designgd/415360.pdf

Incropera, Frank P. Fundamentals of Heat and Mass Transfer / Frank P. Incropera ... [et Al.]. Hoboken, NJ: John Wiley, 2007. Print.

"Pump, PMP-300 [no Nozzles] - Water Cooling Systems, Pc Liquid Cooling Kit, Cpu, Video Card, Hard Drive." Koolance.com. Web. 02 Apr. 2012. <http://www.koolance.com/water-cooling/product_info.php?product_id=950>.

42u Data Center Cooling. N.p., n.d. Web. 24 Jan. 2012. <http://www.42u.com/42u-rack-cooling.htm>.

Pingdom Blog. Pingdom AB, 25 July 2008. Web. 24 Jan. 2012. <http://royal.pingdom.com/2008/07/25/us-data-centers-consuming-as-much-power-as-5-million-houses/>.

Graybar: works to your advantage. N.p., 2012. Web. 9 Apr. 2012. <http://www.graybar.com/applications/data-centers>.

THANK YOU FOR YOUR TIME!

Special thanks to Dr. Kimber, Ricardo Riviera, and

Andy Holmes & his machine shop crew

Questions?