Thermal Design and Performance of Two-Phase Meso-Scale Heat Exchangers

2005 ◽  
Author(s):  
Robert Hannemann ◽  
Joseph Marsala ◽  
Martin Pitasi
Keyword(s):  
Heat Exchangers ◽  
Thermal Design ◽  
Low Flow ◽  
Commercial Application ◽  
Working Fluid ◽  
Small Scale ◽  
Air Cooling ◽  
Cold Plate ◽  
Two Phase ◽  
Meso Scale

Dramatically increased power dissipation in electronic and electro-optic devices has prompted the development of advanced thermal management approaches to replace conventional air cooling using extended surfaces. One such approach is Pumped Liquid Multiphase Cooling (PLMC), in which a refrigerant is evaporated in a cold plate in contact with the devices to be cooled. Heat is then rejected in an air or water-cooled condenser and the working fluid is returned to the cold plate. Reliable, highly efficient, small-scale components are required for the commercial application of this technology. This paper presents experimental results for two-phase meso-scale heat exchangers (cold plates) for use in electronics cooling. The configurations studied include single and multi-pass designs using R134a as the working fluid. With relatively low flow rates, low effective thermal resistances were achieved at power levels as high as 376 W. The results confirm the efficacy of PLMC technology for cooling the most powerful integrated circuits planned for the next decade.

Enabling Thermal Management of High-Powered Server Processors Using Passive Thermosiphon Heat Sink

2019 ◽  
Author(s):  
Devdatta P. Kulkarni ◽  
Priyanka Tunuguntla ◽  
Guixiang Tan ◽  
Casey Carte
Keyword(s):  
Heat Pipe ◽  
High Power ◽  
Heat Sink ◽  
Capital Investment ◽  
Thermal Design ◽  
Heat Sinks ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Two Phase ◽  
Pipe Heat

Abstract In recent years, rapid growth is seen in computer and server processors in terms of thermal design power (TDP) envelope. This is mainly due to increase in processor core count, increase in package thermal resistance, challenges in multi-chip integration and maintaining generational performance CAGR. At the same time, several other platform level components such as PCIe cards, graphics cards, SSDs and high power DIMMs are being added in the same chassis which increases the server level power density. To mitigate cooling challenges of high TDP processors, mainly two cooling technologies are deployed: Liquid cooling and advanced air cooling. To deploy liquid cooling technology for servers in data centers, huge initial capital investment is needed. Hence advanced air-cooling thermal solutions are being sought that can be used to cool higher TDP processors as well as high power non-CPU components using same server level airflow boundary conditions. Current air-cooling solutions like heat pipe heat sinks, vapor chamber heat sinks are limited by the heat transfer area, heat carrying capacity and would need significantly more area to cool higher TDP than they could handle. Passive two-phase thermosiphon (gravity dependent) heat sinks may provide intermediate level cooling between traditional air-cooled heat pipe heat sinks and liquid cooling with higher reliability, lower weight and lower cost of maintenance. This paper illustrates the experimental results of a 2U thermosiphon heat sink used in Intel reference 2U, 2 node system and compare thermal performance using traditional heat sinks solutions. The objective of this study was to showcase the increased cooling capability of the CPU by at least 20% over traditional heat sinks while maintaining cooling capability of high-power non-CPU components such as Intel’s DIMMs. This paper will also describe the methodology that will be used for DIMMs serviceability without removing CPU thermal solution, which is critical requirement from data center use perspective.

Thermal Performance and Key Challenges for Future CPU Cooling Technologies

2005 ◽  
Author(s):  
Ioan Sauciuc ◽  
Ravi Prasher ◽  
Je-Young Chang ◽  
Hakan Erturk ◽  
Gregory Chrysler ◽  
...  
Keyword(s):  
Power Density ◽  
Thermal Performance ◽  
Hot Spot ◽  
Average Power ◽  
Building Blocks ◽  
Thermal Design ◽  
Air Cooling ◽  
Back Side ◽  
Two Phase ◽  
Density Factor

Over the past few years, thermal design for cooling microprocessors has become increasingly challenging mainly because of an increase in both average power density and local power density, commonly referred to as “hot spots”. The current air cooling technologies present diminishing returns, thus it is strategically important for the microelectronics industry to establish the research and development focus for future non air-cooling technologies. This paper presents the thermal performance capability for enabling and package based cooling technologies using a range of “reasonable” boundary conditions. In the enabling area a few key main building blocks are considered: air cooling, high conductivity materials, liquid cooling (single and two-phase), thermoelectric modules integrated with heat pipes/vapor chambers, refrigeration based devices and the thermal interface materials performance. For package based technologies we present only the microchannel building block (cold plate in contact with the back-side of the die). It will be shown that as the hot spot density factor increases, package based cooling technologies should be considered for more significant cooling improvements. In addition to thermal performance, a summary of the key technical challenges are presented in the paper.   This paper was also originally published as part of the Proceedings of the ASME 2005 Heat Transfer Summer Conference.

Thermal Analysis of Cold Plate for Motor Controller Based on Fluent

2012 ◽  
Vol 249-250 ◽  
pp. 691-695
Author(s):  
Gui Lin Lin ◽  
Guo Qing Xu ◽  
Wei Min Li ◽  
Bin Bin Liu
Keyword(s):  
Electric Vehicle ◽  
Optimization Design ◽  
Controller Design ◽  
Electronics Cooling ◽  
Thermal Design ◽  
High Heat Flux ◽  
Air Cooling ◽  
Material Base ◽  
Cold Plate ◽  
Motor Controller

Electronics cooling research has been largely focused on high heat flux removal from computer chips in the recent years. However, the equally important field of high-power electronic devices has been experiencing a major paradigm shift from air cooling to liquid cooling over the last decade. For example, multiple insulated-gate bipolar transistors (IGBT) used in a power drive for motor used in electric vehicle. Motor drive system plays an important impact on electric vehicle’ performance, so thermal design should be considered in the early stages during the motor controller design and layout of the devices. In this paper, a new type of water-cooled cold plate for motor controller was designed, and its cooling ability was analyzed by using different material base on Fluent. The results provide reference on the optimization design of cold plate.

scholarly journals Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 721
Author(s):  
Haiwang Li ◽  
Yujia Li ◽  
Binghuan Huang ◽  
Tiantong Xu
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Flow Resistance ◽  
Stokes Equations ◽  
Geometric Parameters ◽  
Thermal Design ◽  
Low Flow ◽  
High Heat Transfer ◽  
The Impact

Due to the large surface-area-to-volume ratio, microchannel heat exchangers have a higher heat transfer rate compared with traditional scale heat exchangers. In this study, the optimum microchannel cavity with high heat transfer and low flow resistance is designed to further improve microchannel exchangers’ thermal performance. A three-dimensional laminar flow model, consisting of Navier–Stokes equations and an energy conservation equation is solved and the conjugate heat transfer between the silicon basement and deionized water is taken into consideration. The impact of the shape, aspect ratio, size and spacing of the cavity on the thermal performance of microchannel exchangers are numerically investigated, respectively. The results indicated that the cavity on the sidewall can enhance heat transfer and reduce flow resistance simultaneously, and cavities with a relatively small expansion angle and streamlined edge could enhance thermal performance the most. Based on the conclusions, a new cavity shape is proposed, and the simulation results verify its excellent thermal performance as expected. Furthermore, investigation is performed to figure out the optimum design of the new cavity and the optimal geometric parameters of the cavity under different flow conditions have been obtained in principle for microchannel exchangers’ design.

Cooling of High Powered GPUs Using Liquid Nitrogen Cold Plates Made With Additive Manufacturing

2021 ◽  
Author(s):  
Alec Nordlund ◽  
Rachel McAfee ◽  
Rebecca Ledsham ◽  
Joshua Gess
Keyword(s):  
Additive Manufacturing ◽  
Liquid Nitrogen ◽  
Data Center ◽  
Power Efficiency ◽  
Thermal Design ◽  
Cryogenic Cooling ◽  
Air Cooling ◽  
Two Phase ◽  
Computational Performance ◽  
Two Phase Cooling

Abstract Processor energy density is exceeding the capabilities of conventional air-cooling technology, but two-phase cooling has the potential to manage these resulting heat fluxes at reliable temperatures and higher electrical efficiency. When two-phase cooling is used in tandem with overclocking, data center footprints are reduced as individual chip processing power can be set at limits well beyond the manufacturer’s Thermal Design Power (TDP) or nominal operating condition. This study examines how Liquid Nitrogen (LN2) can be used with Additive Manufacturing (AM) and overclocking to increase the computational performance of a commercially available GPU. The power consumption and frequency relationship were established for both the cryogenically cooled solution and a comparative air-cooled solution. The cryogenic solution saw up to a 17.4% increase in compute efficiency and an 18.1% improvement in compute speed with comparable power efficiency at an equivalent performance level to the air-cooled solution. This study considers the computational performance and efficiency gains that can be acquired through cryogenic cooling on an individual graphics card, which can be replicated on a larger scale in data center applications.

Flow Distribution Control Between Two Parallel Meso-Scale Evaporators With Electrohydrodynamic Conduction Pumping

2016 ◽  
Author(s):  
Lei Yang ◽  
Michal Talmor ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Two Phase Flow ◽  
Finite Thickness ◽  
Flow Distribution ◽  
Control Technique ◽  
Working Fluid ◽  
Phase System ◽  
Phase Flow ◽  
Two Phase ◽  
Macro Scale ◽  
Meso Scale

Electrohydrodynamic (EHD) conduction pumps generate pressure to drive dielectric liquids via the electrical Coulomb force exerted within heterocharge layers of finite thickness in the vicinity of the electrodes. By applying an external electric field in a dielectric liquid, the heterocharge layers form due to the net charges as a result of the process of enhanced dissociation of neutral molecules versus the recombination of the generated ions. EHD conduction pumping can be applied to enhance and control mass and heat transfer of both isothermal and nonisothermal liquid and two-phase fluid, with many advantages such as simple design, no moving parts and low power consumption. It also shows its potential as an active control technique for flow distribution for multi-scale systems in both terrestrial and microgravity environment. Flow distribution control based on EHD conduction pumping mechanism was previously investigated in macro-scale. This study experimentally examines its capability in controlling two-phase flow distribution between two parallel meso-scale evaporators. The working fluid was refrigerant HCFC-123. It has been found that an EHD conduction pump could effectively control the two-phase flow distribution via adjusting the flow rate in each branch line, and facilitate the recovery from dry-out condition in two-phase system.

Thermal Design Correlations for Single- and Two-Phase Flow of R-407C in Meso-Scale Heat Exchangers

2004 ◽  
Author(s):  
Yasir M. Shariff ◽  
T. S. Ravigururajan
Keyword(s):  
Flow Boiling ◽  
Thermal Design ◽  
Design Parameters ◽  
Two Phase ◽  
Channel Diameter ◽  
Experimental Database ◽  
Boiling Flow ◽  
Flow Variables ◽  
Saturated Boiling ◽  
Meso Scale

The paper presents correlation development for an experimental database done on R-407C flow in meso-scale horizontal channels. Single-phase, two-phase subcooled, and two-phase saturated boiling flow correlations were developed. The variables considered in this study including essential design parameters, such as, channel diameter, coils pitch and diameter. For flow variables considered are the Reynolds number and the Prandtl number. The purpose of this study is to present new design correlations for flow boiling in a ternary refrigerant mixture at a meso-scale size. The relative influences of enhancement design parameters on friction factor and heat transfer were carried in this parametric analysis of the flow boiling correlations. The resulted correlations developed in this study are compared to available published correlations.

Numerical Simulation of Operating Performance of Heat Exchangers in a Residential Split Air-Conditioner

2011 ◽  
Vol 250-253 ◽  
pp. 3913-3918 ◽  
Author(s):  
Shun Yu Su ◽  
Tian Tian ◽  
Jian Chen
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchangers ◽  
Great Influence ◽  
Working Fluid ◽  
Air Conditioner ◽  
Two Phase ◽  
Air Conditioning System ◽  
Flow And Heat Transfer ◽  
Phase Fluid

The mechanism of fluid flow and heat transfer in the heat exchangers was investigated in this paper. Using R22 as the working fluid, the steady distributed parameter models of condenser and evaporator in a residential split air-conditioner were established based on thermophysical laws such as mass, momentum and energy conservation equations. The regions of two-phase fluid and superheated gas in evaporator and the regions of superheated gas, two-phase fluid and subcooled liquid in condenser were respectively simulated under designed conditions of air-conditioning system. Based on the calculated results, the flow and heat transfer performances of heat exchangers were analyzed. The results show that the two-phase fluid regions in both evaporator and condenser have great influence on the fluid flow and heat transfer performances in it.

Two Phase Boiling Heat Transfer of Water in Minichannel

2017 ◽  
Author(s):  
Ye Tian ◽  
Wei Huang ◽  
Pengfei Li ◽  
Simin Cao ◽  
Yan Sun
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Absolute Error ◽  
Nuclear Industry ◽  
Working Fluid ◽  
Two Phase ◽  
Compact Heat Exchangers ◽  
Compact Size

Printed Circuit Heat Exchangers (PCHE) is a new type of compact heat exchangers, it will be widely used for nuclear industry due to its higher heat transfer area density, compact size, and design flexibility. The hydraulic diameter of PCHE tubes ranges from 1mm to 2mm which belongs to mini-channel according to Kandlikar and Grande (2003)’s study.[1] In this paper, two-phase flow boiling heat transfer of water in mini-channel is discussed. The most of previous literatures in this field mainly focused on flow boiling of refrigerants, but the main working fluid in PCHE tubes is water. A composite correlation of flow boiling of water through mini-channel has been developed on basis of a database of water in this paper. Mean absolute error (MAE) method is used to evaluate relative error. Comparing with the experimental data, the MAE of the new correlation is 23.4%.

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