scholarly journals A multi-channel cooling system for multiple heat source

2016 ◽  
Vol 20 (6) ◽  
pp. 1991-2000 ◽  
Author(s):  
Shanglong Xu ◽  
Weijie Wang ◽  
Zongkun Guo ◽  
Xinglong Hu ◽  
Wei Guo
Keyword(s):  
Heat Sink ◽  
Electronic Device ◽  
Cooling System ◽  
Electronic Devices ◽  
Heat Removal ◽  
Heat Sources ◽  
Power Electronic ◽  
Require Temperature ◽  
Computer Controlled ◽  
Temperature And Pressure

High-power electronic devices with multiple heating elements often require temperature uniformity and operating within their functional temperature range for optimal performance. A multi-channel cooling experiment apparatus is developed for studying heat removal inside an electronic device with multiple heat sources. It mainly consists of a computer-controlled pump, a multi-channel heat sink for multi-zone cooling and the apparatus for measuring the temperature and pressure drop. The experimental results show the system and the designed multi-channel heat sink structure can control temperature distribution of electronic device with multiple heat sources by altering coolant flow rate.

Multiphysics Design and Analysis Simulations for Power Electronic Device Wirebonds

2003 ◽  
Author(s):  
Patrick W. Wilkerson ◽  
Andrzej J. Przekwas ◽  
Chung-Lung Chen
Keyword(s):  
Heat Dissipation ◽  
Electronic Device ◽  
Electronic Devices ◽  
Thermal Conditions ◽  
Simulation Software ◽  
Operating Conditions ◽  
Power Electronic ◽  
Stress Concentrations ◽  
Multiphysics Simulation ◽  
Multiphysics Simulations

Multiscale multiphysics simulations were performed to analyze wirebonds for power electronic devices. Modern power-electronic devices can be subjected to extreme electrical and thermal conditions. Fully coupled electro-thermo-mechanical simulations were performed utilizing CFDRC’s CFD-ACE+ multiphysics simulation software and scripting capabilities. Use of such integrated multiscale multiphysics simulation and design tools in the design process can cut cost, shorten product development cycle time, and result in optimal designs. The parametrically designed multiscale multiphysics simulations performed allowed for a streamlined parametric analysis of the electrical, thermal, and mechanical effects on the wirebond geometry, bonding sites and power electronic device geometry. Multiscale analysis allowed for full device thermo-mechanical analysis as well as detailed analysis of wirebond structures. The multiscale simulations were parametrically scripted allowing for parametric simulations of the device and wirebond geometry as well as all other simulation variables. Analysis of heat dissipation from heat generated in the power-electronic device and through Joule heating were analyzed. The multiphysics analysis allowed for investigation of the location and magnitude of stress concentrations in the wirebond and device. These stress concentrations are not only investigated for the deformed wirebond itself, but additionally at the wirebond bonding sites and contacts. Changes in the wirebond geometry and bonding geometry, easily changed through the parametrically designed simulation scripts, allows for investigation of various wirebond geometries and operating conditions.

Boiling/Evaporation Heat Transfer Augmentation Using Subchannels-Inserted Metal Porous Media

2013 ◽  
Author(s):  
Kazuhisa Yuki ◽  
Masahiro Uemura ◽  
Koichi Suzuki ◽  
Ken-ichi Sunamoto
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Electronic Devices ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Power Electronic ◽  
Copper Particles ◽  
Evaporation Heat

Two-phase flow loop system using a metal porous heat sink is proposed as a cooling system of the future power electronic devices with a heat load exceeding 300W/cm2. In this paper, as the first step, the heat transfer performance of the porous heat sink is evaluated under high heat flux conditions and the applicability and some engineering issues are discussed. The porous medium, which is fabricated by sintering copper particles, has a functional structure with several sub-channels inside it to enhance phase-change as well as discharge of generated vapor outside the porous medium. This porous heat sink is attached onto a heating chip and removes the heat by evaporating cooling liquid passing through the porous medium against the heat flow. Experiments using 30 kW of heating system show that the heat transfer performance of a copper-particles-sintered porous medium with the sub-channels exceeds 800W/cm2 in both high and low subcooling cases and achieves 300W/cm2 at a wall temperature of 150 °C (Tin = 70 °C) and 130 °C (Tin = 70 °C). These results prove that this porous heat sink is applicable enough for cooling 300 W/cm2 class of power electronic devices.

Preliminary Analysis of Unprotected Loss of Heat Sink in Small Long Life Gas Cooled Fast Reactor

2015 ◽  
Vol 751 ◽  
pp. 268-272
Author(s):  
Su'ud Zaki ◽  
Nuri Trianti ◽  
Rosidah M. Indah
Keyword(s):  
Fast Reactor ◽  
Heat Sink ◽  
Channel Model ◽  
Cooling System ◽  
Hot Spot ◽  
Natural Circulation ◽  
Heat Removal ◽  
Reducing Power ◽  
Secondary System ◽  
Heat Removal System

The failure of the secondary side in Gas Cooled Fast Reactor system, which may contain co-generation system, will cause loss of heat sink (LOHS) accident. In this study accident analysis of unprotected loss of heat sink due to the failure of the secondary cooling system has been investigated. The thermal hydraulic model include transient hot spot channel model in the core, steam generator, and related systems. Natural circulation based heat removal system is important to ensure inherent safety capability during unprotected accidents. Therefore the system similar to RVACS (reactor vessel auxiliary cooling system) is also plays important role to limit the level of consequence during the accident. As the results some simulations for small 60 MWt gas cooled fast reactors has been performed and the results show that the reactor can anticipate the failure of the secondary system by reducing power through reactivity feedback and remove the rest of heat through natural circulations based decay heat removal (RVACS system).

CFD-Assisted Optimization of Chimneylike Flows to Cool an Electronic Device

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Varghese Panthalookaran
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Energy Efficient ◽  
Electronic Device ◽  
Cooling System ◽  
Electronic Devices ◽  
Cost Effective ◽  
Transfer Rates ◽  
Slot Opening ◽  
Convection Cooling

Natural convection cooling provides a reliable, cost-effective, energy-efficient and noise-free method to cool electronic equipment. However, the heat transfer coefficient associated with natural convection mode is usually insufficient for electronic cooling and it requires enhancement. Chimneylike flows developed within the cabinets of electronic devices can provide better mass flow and heat transfer rates and can lead to greater cooling efficiency. Constraints in the design of natural convection cooling systems include efficiency of packing, aesthetics, and concerns of material reduction. In this paper, methods based on computational fluid dynamics are used to study the effects of parameters such as (1) vertical alignment of the slots, (2) horizontal alignment of slots, (3) area of slots, (4) differential slot opening, and (5) zonal variation in heat generation on natural convection cooling within such design constraints. Insights thus derived are found useful for designing an energy-efficient and ecofriendly cooling system for electronic devices.

Multiphase Submerged Jet Impingement Cooling Utilizing Nanostructured Plates

2012 ◽  
Author(s):  
Ebru Demir ◽  
Ali Kosar ◽  
Turker Izci ◽  
Osman Yavuz Perk ◽  
Muhsincan Sesen ◽  
...  
Keyword(s):  
Cooling System ◽  
Electronic Devices ◽  
Control Sample ◽  
Heat Removal ◽  
Jet Impingement ◽  
Impinging Jets ◽  
Copper Plate ◽  
Impingement Cooling ◽  
Surface Morphologies ◽  
Aluminum Base

An experimental setup is designed to simulate the heat dissipated by electronic devices and to test the effects of nanostructured plates in enhancing the heat removal performance of jet impingement systems in such cooling applications under boiling conditions. Prior experiments conducted in single phase have shown that such different surface morphologies are effective in enhancing the heat transfer performance of jet impingement cooling applications. In this paper, results of the most recent experiments conducted using multiphase jet impingement cooling system will be presented. Distilled water is propelled into four microtubes of diameter 500 μm that provide the impinging jets to the surface. Simulation of the heat generated by miniature electronic devices is simulated through four aluminum cartridge heaters of 6.25 mm in diameter and 31.75 mm in length placed inside an aluminum base. Nanostructured plates of size 35mm×30mm and different surface morphologies are placed on the surface of the base and two thermocouples are placed to the surface of the heating base and the base is submerged into deionized water. Water jets generated using microtubes as nozzles are targeted to the surface of the nanostructured plate from a nozzle to surface distance of 1.5 mm and heat removal characteristics of the system is studied for a range of flow rates and heat flux, varying between 107.5–181.5 ml/min and 1–400000 W/m2, respectively. The results obtained using nanostructured plates are compared to the ones obtained using a plain surface copper plate as control sample and reported in this paper.

Review and Status of the Gen-IV CANDU-SCWR Passive Moderator Core Cooling System

2008 ◽  
Author(s):  
H. F. Khartabil
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Natural Circulation ◽  
Power Level ◽  
Heat Removal ◽  
Circulation System ◽  
The Past ◽  
Test Loop ◽  
Flow Oscillations ◽  
Core Cooling

Enhanced safety is an important priority in the development of Generation IV reactors, which can be accomplished through the use of improved passive heat removal systems. In CANDU® reactors, the separation between the low-pressure moderator and high-pressure coolant provides a unique passive heat sink for decay heat removal during accident scenarios. Methods for enhancing this passive heat sink for the GenIV CANDU-SCWR (supercritical water cooled reactor) have been under investigation for the past several years to support a “no core melt” reactor design concept (1, 2). Initially, to test feasibility, tests and analysis at AECL studied a full-height passive cooling loop and showed that a flashing-driven natural circulation system was possible in principle. However, flow oscillations were observed at low powers and could not be readily explained through analysis. While these oscillations were not considered to be detrimental to the heat removal capability, additional separate-effects experiments were conducted and causal mechanisms proposed for the oscillations. In addition, these separate effects tests suggested that oscillations could be avoided at any power level by suitable design. A new test loop with a more representative geometry was recently constructed and commissioned. Preliminary commissioning tests confirmed conclusions from the separate effects tests. In this paper, the new tests are compared to the past tests to explain the improved and more stable loop operation. This comparison suggests that a complete system coupled to an ultimate heat sink has the potential to improve loop operation even more by eliminating or significantly reducing flow oscillations at low powers. Plans for validating this conclusion will be provided.

Large Area 4H SiC Products for Power Electronic Devices

2016 ◽  
Vol 858 ◽  
pp. 11-14 ◽  
Author(s):  
Ian Manning ◽  
Jie Zhang ◽  
Bernd Thomas ◽  
Edward Sanchez ◽  
Darren Hansen ◽  
...  
Keyword(s):  
Basal Plane ◽  
Electronic Device ◽  
Electronic Devices ◽  
Power Electronic ◽  
Quality Improvements ◽  
Large Area ◽  
Mean Values ◽  
Dislocation Densities ◽  
Basal Plane Dislocation ◽  
Device Applications

Efforts to develop 150 mm 4H SiC bare wafer and epitaxial substrates for power electronic device applications have resulted in quality improvements, such that key metrics match or outperform 100 mm substrates. Total dislocation densities and threading screw dislocation densities measured for 150 mm wafers were ~4100 cm-2 and ~100 cm-2, respectively, compared with values of ~5900 cm-2 and ~300 cm-2 measured for 100 mm wafers. While median basal plane dislocation counts in 150 mm samples exceed those of the smaller platform, a nearly 45% reduction was realized, resulting in a median density of ~3900 cm-2. Epilayers grown on 150 mm substrates likewise exhibit quality metrics that are comparable to 100 mm samples, with median thickness and doping sigma/mean values of 1.1% and 4.4%, respectively.

scholarly journals Gyroton with the Corrugated Resonator

Plasma ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Stanislav Kolosov ◽  
Alexander Kurayev ◽  
Alexey Rak ◽  
Semen Kurkin ◽  
Artem Badarin ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electronic Device ◽  
Power Conversion ◽  
Electronic Devices ◽  
Circular Waveguide ◽  
Beam Power ◽  
Power Electronic ◽  
Microwave Electronic ◽  
New Type ◽  
Rectilinear Electron Beam

A new type of high-power electronic device—a gyroton with a corrugated resonator—is described and investigated. Spatial bunching of the electron beam does not occur in this device, however, highly efficient electron beam power conversion into the rotating electromagnetic field power is possible. The rectilinear electron beam deviates from the axis by the slow TM11 wave, then it gives up longitudinal energy to the same wave with more than 78% efficiency, and an output power up to 30 MW. The developed mathematical model of the interaction of the relativistic electron beam with an irregular circular waveguide and resonator fields presented in this article can be used to calculate and optimize the processes occurring in various microwave electronic devices, such as gyrotrons, gyrotons, TWT, Gyro-TWT, and BWT.

Cooling Performance Evaluation of Synthetic Jet Based Thermal Solution Module

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Ahmad Jalilvand ◽  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Yoji Kawahara ◽  
Randeep Singh ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Removal ◽  
Synthetic Jet ◽  
Air Jet ◽  
Convective Thermal ◽  
Thermal Solution ◽  
Pipe Heat

The convective thermal resistance which represents the heat removal from the heat sink surface of a heat pipe/heat sink module to mean coolant flow temperature is often a dominant contributor to the overall thermal resistance of a heat pipe/heat sink module or remote heat exchange (RHE). RHE is a thermal solution module composed of a heat spreader, thin flattened heat pipe with low profile heat sink which is widely used for the thermal management of compact portable electronic devices. Minimizing the convective thermal resistance at the heat sink of RHE as well as thickness reduction is often an important objective for the thermal designers. Recently, an alternate air mover system which operates based on piezoelectricity is developed. This device is called dual cooling jet (DCJ) in short which can be fabricated with very small thickness down to 1.0 mm. Thin DCJ as a synthetic jet generates air jet with more than 7 m/s air flow velocity which is promising for the increasing demands of thinner next generation portable electronic devices. DCJ is a promising device to dissipate the heat from the heat sink of a RHE. In this work, the performance of RHE is evaluated when heat is dissipated from its heat sink by DCJ. The results are compared with conventional rotary fan. The results show that more than 12 W of heat can be dissipated by DCJ which can easily compete with some commercialized rotary mini blowers while having much smaller thickness. Various configuration of heat sink–DCJ combinations as well as size and shape of both heat sink and DCJ are tested and based on thermal resistance data, cooling effectiveness of DCJ is studied.

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