Passive Cooling of Protruding Electronic Components by Latent Heat of Fusion Storage

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Mustapha Faraji ◽  
Hamid El Qarnia
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Heat Removal ◽  
Electronic Component ◽  
Heat Of Fusion ◽  
Volume Control ◽  
Maximum Temperature ◽  
Algebraic Equations ◽  
Electronic Components ◽  
Control Approach

The aim of the present work is to study the thermal performance of a hybrid heat sink used for cooling management of protruding substrate-mounted electronic chips. The power generated in electronic chips is dissipated in phase change material (PCM) (n-eicosane with melting temperature Tm=36°C) that filled a rectangular enclosure. The advantage of using this cooling strategy is that the PCMs are able to absorb a high amount of heat generated by electronic component (EC) without acting the fan, during the charging process (melting of the PCM). A two-dimensional mathematical model was developed in order to analyze and optimize a heat sink. The governing equations for masse, momentum, and energy transport were developed and discretized by using the volume control approach. The resulting algebraic equations were next solved iteratively by using tri diagonal matrix algorithm. A series of numerical investigations were conducted in order to examine the effects of the heat generation based Rayleigh number, Ra, and the position of the bottom electronic component, Lh, on the thermal behavior of the proposed cooling system. Results are obtained for velocity and temperature distributions, maximum temperature heat sources, percentage contribution of plate (substrate) heat conduction on the heat removal from electronic components, temperature profile within finite conductive plate and local heat flux density at the plate—modules/PCM interface. The effect of these two key parameters on the electronic component working time (time required by electronic components to reach a critical temperature, Tcr) was analyzed.

Numerical Analysis of a Hybrid Heat Sink Using Phase Change Material: Application to Cooling of Electronic Components

2008 ◽  
Author(s):  
Mustapha Faraji ◽  
Hamid El Qarnia
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Heat Sink ◽  
Energy Transport ◽  
Electronic Component ◽  
Volume Control ◽  
Algebraic Equations ◽  
Control Approach ◽  
Change Material

The aim of the present work is to study the thermal performance of a hybrid heat sink used for cooling management of protruding substrate-mounted electronic chips. The power generated in electronic chips is dissipated in phase change material (PCM n-ecosane with melting temperature Tm = 36°C) that filled a rectangular enclosure. The advantage of using this cooling strategy is that the PCMs are able to absorb a high amount of heat generated by electronic component (EC) without acting the fan, during the charging process (melting of the PCM). A (2D) mathematical model was developed in order to analyze and optimize a heat sink. The governing equations for masse, momentum and energy transport were developed and discretised by using the volume control approach. The resulting algebraic equations were next solved iteratively by using TDMA algorithm. Numerical investigations were conducted in order to optimize the thermal performance of the heat sink. The optimization involves determination of the key parameters of the heat sink that maximize the time required by the base of the electronic component to reach a critical temperature.

Design and Optimization of a Composite Heat Spreader to Improve the Thermal Management of a 3D Integrated Circuit

2021 ◽  
Author(s):  
Andisheh Tavakoli ◽  
Kambiz Vafai
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Variable Temperature ◽  
Heat Removal ◽  
High Conductivity ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Optimal Distribution ◽  
Heat Spreader ◽  
The Impact

Abstract The present study analyzes the optimal distribution of a limited amount of high thermal conductivity material to enhance the heat removal of circular 3D integrated circuits, IC. The structure of the heat spreader is designed as a composite of high thermal conductivity (Boron Arsenide) and moderate thermal conductivity (copper) materials. The volume ratio of high-conductivity inserts to the total volume of the spreader is set at a fixed pertinent ratio. Two different boundary conditions of constant and variable temperature are considered for the heat sink. To examine the impact of adding high-conductivity inserts on the cooling performance of the heat spreader, various patterns of the single and double ring inserts are studied. A parametric study is performed to find the optimal location of the rings. Moreover, the optimal distribution of the high-conductivity material between the inner and outer rings is found. The results show that for the optimal conditions, the maximum temperature of the 3D IC is reduced up to 10%; while the size of the heat sink, and heat spreader can be diminished by as much as 200%.

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).

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.

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.

scholarly journals Optimization of Air Cooling System Using Adjoint Solver Technique

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3753
Author(s):  
Grzegorz Czerwiński ◽  
Jerzy Wołoszyn
Keyword(s):  
Heat Source ◽  
Heat Sink ◽  
Cooling System ◽  
Geometric Model ◽  
Maximum Temperature ◽  
Air Cooling ◽  
Ansys Fluent ◽  
Source Temperature ◽  
Heat Source Temperature ◽  
Air Cooling System

Air cooling systems are currently the most popular and least expensive solutions to maintain a safe temperature in electronic devices. Heat sinks have been widely used in this area, allowing for an increase in the effective heat transfer surface area. The main objective of this study was to optimise the shape of the heat sink geometric model using the Adjoint Solver technique. The optimised shape in the context of minimal temperature value behind the heat sink is proposed. The effect of radiation and trapezoidal fin shape on the maximum temperature in the cooling system is also investigated. Simulation studies were performed in Ansys Fluent software using the Reynolds—averaged Navier–Stokes technique. As a result of the simulation, it turned out that not taking into account the radiation leads to an overestimation of temperatures in the system—even by 14 ∘C. It was found that as the angle and height of the fins increases, the temperature value behind the heat sink decreases and the heat source temperature increases. The best design in the context of minimal temperature value behind the heat sink from all analysed cases is obtained for heat sink with deformed fins according to iteration 14. The temperature reduction behind the heat sink by as much as 25 ∘C, with minor changes in heat source temperature, has been achieved.

scholarly journals Effect of nanoparticles on the thermal behaviour of a NePCM-based heat sink

2020 ◽  
Vol 330 ◽  
pp. 01020
Author(s):  
Hamza Faraji ◽  
Mustapha Faraji ◽  
Mustapha El Alami
Keyword(s):  
Heat Sink ◽  
Melting Process ◽  
Electronic Component ◽  
Maximum Temperature ◽  
Computational Investigation ◽  
Volumetric Concentration ◽  
Storage Unit ◽  
Latent Heat Storage ◽  
Volumetric Rate ◽  
Change Material

This work presents a computational investigation of the passive cooling of an electronic component in a latent heat storage unit filled with nano-enhanced phase change material (NePCM). The electronic component is flush mounted on a substrate (motherboard) in the centre of the bottom wall of a rectangular enclosure. This electronic component generates heat at a constant and uniform volumetric rate. A 2D mathematical model based on the conservation equations of mass, momentum and energy has been developed using the enthalpy- porosity method. The effect of natural convection in the molten NePCM is considered during the melting process. The centrepiece of this study is to improve the functionality of PCM trough insertion of nanoparticles. Computational surveys have been developed to evaluate the effect of volumetric concentration as well as the nanoparticles type by monitoring the evolution of the maximum temperature of the electronic component, the average Nusselt number and the velocity field. These investigations show that the volumetric concentration and the nanoparticles type are two main factors to take into account for an improvement in performance of the NePCM-based heat sink.

Spray Cooling for Time Resolved Emission Measurements of ICs

2004 ◽  
Author(s):  
Rama R. Goruganthu ◽  
David Bethke ◽  
Shawn McBride ◽  
Tom Crawford ◽  
Jonathan Frank ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Flip Chip ◽  
Cooling System ◽  
Spray Cooling ◽  
Junction Temperature ◽  
Maximum Temperature ◽  
Uniform Heat Flux ◽  
High Heat Flux ◽  
Time Resolved

Abstract Spray cooling is implemented on an engineering tool for Time Resolved Emission measurements using a silicon solid immersion lens to achieve high spatial resolution and for probing high heat flux devices. Thermal performance is characterized using a thermal test vehicle consisting of a 4x3 array of cells each with a heater element and a thermal diode to monitor the temperature within the cell. The flip-chip packaged TTV is operated to achieve uniform heat flux across the die. The temperature distribution across the die is measured on the 4x3 grid of the die for various heat loads up to 180 W with corresponding heat flux of 204 W/cm2. Using water as coolant the maximum temperature differential across the die was about 30 °C while keeping the maximum junction temperature below 95 °C and at a heat flux of 200 W/cm2. Details of the thermal performance of spray cooling system as a function of flow rate, coolant

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