A Novel Concept Methodology of In-direct Cold Plate Liquid Cooling Design for Data Center in CPU Socket Area

Thermal analysis and thermal management of lithium-ion batteries for utilization in electric vehicles is vital. In order to investigate the thermal behavior of a lithium-ion battery, a liquid cooling design is demonstrated in this research. The influence of cooling direction and conduit distribution on the thermal performance of the lithium-ion battery is analyzed. The outcomes exhibit that the appropriate flow rate for heat dissipation is dependent on different configurations for cold plate. The acceptable heat dissipation condition could be acquired by adding more cooling conduits. Moreover, it was distinguished that satisfactory cooling direction could efficiently enhance the homogeneity of temperature distribution of the lithium-ion battery.

Download Full-text

Minimizing the Effects of On-Chip Hotspots Using Multi-Objective Optimization of Flow Distribution in Water-Cooled Parallel Microchannel Heatsinks

Journal of Electronic Packaging ◽

10.1115/1.4048590 ◽

2020 ◽

Vol 143 (2) ◽

Author(s):

Yaser Hadad ◽

Vahideh Radmard ◽

Srikanth Rangarajan ◽

Mahdi Farahikia ◽

Gamal Refai-Ahmed ◽

...

Keyword(s):

Flow Distribution ◽

System Level ◽

Temperature Uniformity ◽

Liquid Cooling ◽

Two Phase ◽

Chip Area ◽

Chip Temperature ◽

Cooling Design ◽

On Chip ◽

Novel Concept

Abstract The industry shift to multicore microprocessor architecture will likely cause higher temperature nonuniformity on chip surfaces, exacerbating the problem of chip reliability and lifespan. While advanced cooling technologies like two phase embedded cooling exist, the technological risks of such solutions make conventional cooling technologies more desirable. One such solution is remote cooling with heatsinks with sequential conduction resistance from chip to module. The objective of this work is to numerically demonstrate a novel concept to remotely cool chips with hotspots and maximize chip temperature uniformity using an optimized flow distribution under constrained geometric parameters for the heatsink. The optimally distributed flow conditions presented here are intended to maximize the heat transfer from a nonuniform chip power map by actively directing flow to a hotspot region. The hotspot-targeted parallel microchannel liquid cooling design is evaluated against a baseline uniform flow conventional liquid cooling design for the industry pressure drop limit of approximately 20 kPa. For an average steady-state heat flux of 145 W/cm2 on core areas (hotspots) and 18 W/cm2 on the remaining chip area (background), the chip temperature uniformity is improved by 10%. Moreover, the heatsink design has improved chip temperature uniformity without a need for any additional system level complexity, which also reduces reliability risks.

Download Full-text

Thermodynamic Analysis of Full Liquid-Cooled Data Centers

Volume 1: Thermal Management ◽

10.1115/ipack2015-48439 ◽

2015 ◽

Cited By ~ 2

Author(s):

A. Bhalerao ◽

A. P. Wemhoff

Keyword(s):

Thermodynamic Analysis ◽

Data Center ◽

Thermodynamic Efficiency ◽

Second Law ◽

Heat Output ◽

Cold Plate ◽

Liquid Cooling ◽

Second Law Analysis ◽

Cold Plates ◽

The Individual

One way to model the thermodynamic efficiency of a data center is to perform a second-law analysis using exergy calculations of the individual components. The in-house data center modeling tool Villanova Thermodynamic Analysis of Systems (VTAS) was applied to determine the effect of direct liquid cooling with cold plates on data center efficiency. The effectiveness of the cold plate as a function of the heat output of the servers was also examined. VTAS was used to study a configuration of two rows with eight racks each. Each rack was assumed to have twelve servers, each producing 200 W of heat. In addition to the cold plates and servers, this configuration also included a computer room air handling (CRAH) unit, a chiller, and a cooling tower. Preliminary results show that data center second-law efficiency increases as the cold plate removes more heat than the CRAH unit. Specifically, when using cold plates to remove all of the heat from the servers, the overall data center exergy destruction was reduced by over 30% compared to a configuration with only a CRAH unit and between 12–18% compared to a configuration with hybrid liquid-air technologies, thus showing that configurations with direct liquid cooling are thermodynamically more favorable. Furthermore, the effectiveness of the cold plate increases as the heat output of each server increases, suggesting that cold plates are most effective when removing a greater amount of heat.

Download Full-text

Study on Copper Cold Plate Designs for Electronics Liquid Cooling System

Heat Transfer, Volume 1 ◽

10.1115/imece2006-16242 ◽

2006 ◽

Author(s):

Yi. Feng ◽

Y. Wang ◽

C. Y. Huang

Keyword(s):

Heat Transfer ◽

Thermal Performance ◽

Cooling System ◽

Pure Copper ◽

Cold Plate ◽

Performance Limits ◽

Liquid Cooling ◽

Cold Plates ◽

Management Approaches ◽

Liquid Cooling System

The increasing power consumption of microelectronic systems and the dense layout of semiconductor components leave very limited design spaces with tight constraints for the thermal solution. Conventional thermal management approaches, such as extrusion, fold-fin, and heat pipe heat sinks, are somehow reaching their performance limits, due to the geometry constraints. Currently, more studies have been carried out on the liquid cooling technologies, as the flexible tubing connection of liquid cooling system makes both the accommodation in constrained design space and the simultaneous cooling of multi heating sources feasible. To significantly improve the thermal performance of a liquid cooling system, heat exchangers with more liquid-side heat transfer area with acceptable flow pressure drop are expected. This paper focuses on the performance of seven designs of source heat exchanger (cold plate). The presented cold plates are all made in pure copper material using wire cutting, soldering, brazing, or sintering process. Enhanced heat transfer surfaces such as micro channel and cooper mesh are investigated. Detailed experiments have been conducted to understand the performance of these seven cooper cold plates. The same radiators, fan, and water pump were connected with each cooper cold plate to investigate the overall thermal performance of liquid cooling system. Water temperature readings at the inlets and outlets of radiators, pump, and colder plate have been taken to interpret the thermal resistance distribution along the cooling loop.

Download Full-text

Thermal Analysis of Cold Plate for Direct Liquid Cooling of High Performance Servers

Journal of Electronic Packaging ◽

10.1115/1.4044130 ◽

2019 ◽

Vol 141 (4) ◽

Cited By ~ 2

Author(s):

Bharath Ramakrishnan ◽

Yaser Hadad ◽

Sami Alkharabsheh ◽

Paul R. Chiarot ◽

Bahgat Sammakia

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Thermal Resistance ◽

High Heat ◽

High Heat Flux ◽

Cold Plate ◽

Liquid Cooling ◽

Maximum Heat ◽

Effective Heat ◽

Cold Plates

Data center energy usage keeps growing every year and will continue to increase with rising demand for ecommerce, scientific research, social networking, and use of streaming video services. The miniaturization of microelectronic devices and an increasing demand for clock speed result in high heat flux systems. By adopting direct liquid cooling, the high heat flux and high power demands can be met, while the reliability of the electronic devices is greatly improved. Cold plates which are mounted directly on to the chips facilitate a lower thermal resistance path originating from the chip to the incoming coolant. An attempt was made in the current study to characterize a commercially available cold plate which uses warm water in carrying the heat away from the chip. A mock package mimicking a processor chip with an effective heat transfer area of 6.45 cm2 was developed for this study using a copper block heater arrangement. The thermo-hydraulic performance of the cold plates was investigated by conducting experiments at varying chip power, coolant flow rates, and coolant temperature. The pressure drop (ΔP) and the temperature rise (ΔT) across the cold plates were measured, and the results were presented as flow resistance and thermal resistance curves. A maximum heat flux of 31 W/cm2 was dissipated at a flow rate of 13 cm3/s. A resistance network model was used to calculate an effective heat transfer coefficient by revealing different elements contributing to the total resistance. The study extended to different coolant temperatures ranging from 25 °C to 45 °C addresses the effect of coolant viscosity on the overall performance of the cold plate, and the results were presented as coefficient of performance (COP) curves. A numerical model developed using 6SigmaET was validated against the experimental findings for the flow and thermal performance with minimal percentage difference.

Download Full-text

Hybrid cooled data center using above ambient liquid cooling

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems ◽

10.1109/itherm.2010.5501426 ◽

2010 ◽

Cited By ~ 7

Author(s):

Brandon A Rubenstein ◽

Roy Zeighami ◽

Robert Lankston ◽

Eric Peterson

Keyword(s):

Data Center ◽

Liquid Cooling

Download Full-text

Application of Micro-Channel Fin for Cold Plate of Liquid Cooling System and Vapor Chamber

ASME 2009 InterPACK Conference, Volume 2 ◽

10.1115/interpack2009-89144 ◽

2009 ◽

Cited By ~ 2

Author(s):

Koichi Mashiko ◽

Masataka Mochizuki ◽

Yuji Saito ◽

Yasuhiro Horiuchi ◽

Thang Nguyen ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Resistance ◽

Thermal Performance ◽

Cooling System ◽

Cold Plate ◽

Micro Channel ◽

Vapor Chamber ◽

Liquid Cooling ◽

Liquid Cooling System ◽

Heat Spreading

Recently energy saving is most important concept for all electric products and production. Especially, in Data-Center cooling system, power consumption of current air cooling system is increasing. For not only improving thermal performance but also reducing electric power consumption of this system, liquid cooling system has been developed. This paper reports the development of cold plate technology and vapor chamber application by using micro-channel fin. In case of cold plate application, micro-channel fin technology is good for compact space design, high thermal performance, and easy for design and simulation. Another application is the evaporating surface for vapor chamber. The well-known devices for effective heat transfer or heat spreading with the lowest thermal resistance are heat pipes and vapor chamber, which are two-phase heat transfer devices with excellent heat spreading and heat transfer characteristics. Normally, vapor chamber is composed of sintered power wick. Vapor chamber container is mechanically supported by stamped pedestal or wick column or solid column, but the mechanical strength is not enough strong. So far, the application is limited in the area of low strength assembly. Sometime the mechanical supporting frame is design for preventing deformation. In this paper, the testing result of sample is described that thermal resistance between the heat source and the ambient can be improved approximately 0.1°C/W by using the micro-channel vapor chamber. Additionally, authors presented case designs using vapor chamber for cooling computer processors, and proposed ideas of using micro-channel vapor chamber for heat spreading to replace the traditional metal plate heat spreader.

Download Full-text