The below includes recent research in liquid cooling.
Test results from the comparison of three liquid cooling methods for high-power processors
Guy R. Wagner, Joseph R. Schaadt, Justin Dixon, Gary Chan, William Maltz, Kamal Mostafavi & David Copeland
This study compares three different liquid cooling technologies to determine which of the three methods is able to cool the highest power density processor chips. The first method consists of pumping a liquid coolant through a cold plate mounted over a 25.4 mm square heat source. The second method is two-phase immersion cooling of the 25.4 mm square heat source in a bath of 3M Novec® 649 liquid with a boiling point of 49°C. The third method of cooling consists of single-phase immersion cooling of the 25.4 mm square heat source using mineral oil as the coolant. This method was tested under both natural convection and forced convection conditions. An experimental setup, consisting of a heater module with attachment to the cooling solution was designed and built. The apparatus was used to determine the maximum power dissipation that can be supported in a 25.4 mm x 25.4 mm area for each of the three cooling solutions. Note that uniform power dissipation is assumed over the die surface. The measured temperature is assumed to be equivalent to the temperature of a die with the same surface area. The maximum die temperature was set to 100 °C and the power required to reach that temperature was recorded for each of the cooling methods.
2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)
https://doi.org/10.1109/ITHERM.2016.7517605
An Integrated Liquid Cooling System Based on Galinstan Liquid Metal Droplets
Jiu Yang Zhu, Shi-Yang Tang, Khashayar Khoshmanesh, and Kamran Ghorbani
The continued miniaturization of electronic components demands integrated liquid cooling systems with minimized external connections and fabrication costs that can be implanted very close to localized hot spots. This might be challenging for existing liquid cooling systems because most of them rely on external pumps, connecting tubes, and microfabricated heat sinks. Here, we demonstrate an integrated liquid cooling system by utilizing a small droplet of liquid metal Galinstan, which is placed over the hot spot. Energizing the liquid metal droplet with a square wave signal creates a surface tension gradient across the droplet, which induces Marangoni flow over the surface of droplet. This produces a high flow rate of coolant medium through the cooling channel, enabling a “soft” pump. At the same time, the high thermal conductivity of liquid metal extends the heat transfer surface and facilitates the dissipation of heat, enabling a “soft” heat sink. This facilitates the rapid cooling of localized hot spots, as demonstrated in our experiments. Our technology facilitates customized liquid cooling systems with simple fabrication and assembling processes, with no moving parts that can achieve high flow rates with low power consumption.
ACS Appl. Mater. Interfaces, 2016, 8 (3), pp 2173–2180
DOI: 10.1021/acsami.5b10769
Publication Date (Web): December 30, 2015
Copyright © 2015 American Chemical Society
More details and download info at:
http://pubs.acs.org/doi/abs/10.1021/acsami.5b10769
Small Form Factor Peltier-Based Liquid Cooling for High Power Density Electronics
Arunima Panigrahy, Ying Feng Pang, Amy Xia and Victor P. Polyanko
Water block and thermoelectric cooler (TEC) are two of the main components in a peltier-based cooling solutions. An optimized water block design and high performance TEC are the key to having a good peltier-based cooling solution. In this study, experimental investigations were performed on small form-factor peltier-based cooling solutions designed for high density electronics. The experiments were conducted in four incremental steps in evaluating the thermal performance of water block with different manufacturing options, different sizes and capabilities of the off-the-shelf TECs, TECs’ optimal operating voltage, thermal performance of the peltier-based liquid cooling solutions, and finally the reliability of the TECs through temperature cycling.
From:
ASME 2016 International Mechanical Engineering Congress and Exposition
Volume 10: Micro- and Nano-Systems Engineering and Packaging
Phoenix, Arizona, USA, November 11–17, 2016
More details and download info at:
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2602781
Thermal Simulation for Two-Phase Liquid Cooling 3D-ICs
Hong-Wen Chiou and Yu-Min Lee
This work presents an algorithm for simulating more accurate temperature distribution in two-phase liquid cooling for three-dimensional integrated circuits than the state of-the-art methods by utilizing local multi-linear interpolation techniques on heat transfer coefficients between the microchannel and silicon substrate, and considering the interdependence between the thermal conductivity of silicon and temperature values. The experimental results show that the maximum and average errors are only 9.7% and 6.7% compared with the measurements, respectively.
From:
Journal of Computer and Communications, 2016, 4, 33-45
http://dx.doi.org/10.4236/jcc.2016.415003
PDF download at:
http://file.scirp.org/pdf/JCC_2016112817235322.pdf
Energy Simulations of Data Centers With Hybrid Liquid/Air Cooling and Waste Heat Re-Use
Seungho Mok, Yogendra K. Joshi, Satish Kumar and Ronald R. Hutchins
This study focuses on developing computational models for hybrid or liquid cooled data centers that may reutilize waste heat. A data center with 17 fully populated racks with IBM LS20 blade servers, which consumes 408 kW at the maximum load, is considered. The hybrid cooling system uses a liquid to remove the heat produced by high power components, while the remaining low power components are cooled by air. The paper presents three hybrid cooling scenarios. For the first two cases, air is cooled by direct expansion (DX) cooling system with air-side economizer. Unlike the cooling air, two different approaches for cooling water are investigated: air-cooled chiller and ground water through liquid-to-liquid heat exchanger. Waste heat re-use for pre-heating building water in co-located facilities is also investigated for the second scenario. In addition to the hybrid cooling models, a fully liquid cooling system is modeled as the third scenario for comparison with hybrid cooling systems. By linking the computational models, power usage effectiveness (PUE) for all scenarios can be calculated for selected geographical locations and data center parameters. The paper also presents detailed analyses of the cooling components considered and comparisons of the PUE results.
From:
ASME 2016 International Mechanical Engineering Congress and Exposition
Volume 8: Heat Transfer and Thermal Engineering
Phoenix, Arizona, USA, November 11–17, 2016
Conference Sponsors: ASME
ISBN: 978-0-7918-5062-6
Copyright © 2016 by ASME
More details and download info at:
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2602531
