Analysis and Performance Comparison of Competing Desktop Cooling Technologies

Author(s):  
Niru Kumari ◽  
Shankar Krishnan ◽  
Suresh V. Garimella

The present work compares the performance of various competing thermal management technologies for the desktop sector. An air-cooled heat sink used for the Intel Pentium 4 Processor is used as the baseline for comparison. Heat sinks based on metal foams, microchannels (with single-phase liquid) and jet impingement (with air and single-phase liquid) are compared based on total heat sink system thermal resistance and heat dissipation capacity. The analysis is carried out under the constraints of a fixed heat sink volume available in a typical desktop, and a fixed ambient air temperature. The comparison of thermal resistances is made under the constraint of the same pumping power as in the baseline heat sink. The maximum heat dissipation possible using a particular heat sink technology is estimated and this can be used to select technologies to meet future thermal challenges as outlined in the International Technology Roadmap for Semiconductors (ITRS). The results show that microchannel and liquid jet impingement cooling provide the greatest heat removal rates under the given constraints. The maximum power dissipation for these cases is almost double that of the baseline air-cooled heat sink. Under the chosen constant value of the junction to heat sink resistance, only modest improvements in heat removal rate are obtained with the microchannel and jet impingement technologies even if the pumping power constraint is relaxed, and a specific pump curve is used instead. The junction to heat sink resistance is significantly higher than the heat sink to ambient resistance, and is the key determinant in the comparisons.

Author(s):  
Nemat Baghernezhad ◽  
Omid Abouali

This paper presents an investigation for two types of the grooves (rectangular and arc shapes) fabricated in the microchannel surfaces which leads to enhancement in single phase cooling. The pressure drop and heat transfer characteristic of the single phase microchannel heat sink were investigated numerically for laminar flow. For this purpose the conjugate heat transfer problem involving simultaneous determination of the temperature field in both solid and liquid regions was solved numerically. The heat sink includes an array of rectangular microchannels with grooved surface structures in the side walls and floor of the channel. The effect of these grooves on the pressure drop, outlet temperature of cooling fluid and the heat transfer rate were analyzed. The result showed that using a microchannel with grooved surfaces has a noticeable effect and heat removal rate can be increased using this technique. Also the grooves with the arc shapes have a better performance compared with a rectangular shape groove.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012245
Author(s):  
Pritam V. Mali ◽  
Harshvardhan H. Patil ◽  
Girish B. Pawar ◽  
Yuvaraj P. Ballal ◽  
Pradip B. Patil

Abstract An electric motor, a battery and an inverter are the key components of any hybrid vehicle. The most commonly used switching device in the electric power conversion system is Insulated Gate Bipolar Transistor (IGBT) modules. Heat sinks with their fins are optimized to provide the maximum heat flow to the surrounding and Pure copper is used as it has high thermal conductivity with reasonable heat resistance. This helps to decrease the temperature of the IGBT and heat will spread to the fins. Parallel forced air cooling is utilised to give maximum possible heat removal rate. Further experimentation was done on a IGBT using an Inverter circuit and it was analyzed on ANSYS software and it was observed that the results obtained by numerical method and experimental method are approximately same.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
O. Abouali ◽  
N. Baghernezhad

This paper presents a numerical investigation for two types of grooves (rectangular and arc shapes) fabricated in the microchannel surfaces, which leads to enhancement in single-phase cooling. The pressure drop and heat transfer characteristics of the single-phase microchannel heat sink were investigated numerically for laminar flow. For this purpose, the conjugate heat transfer problem involving simultaneous determination of temperature fields in both solid and liquid regions was solved numerically. The numerical model was validated with comparison to experimental data, in which good agreement was seen. A simple microchannel with available experimental data was selected, and it was shown that using grooved surfaces on this microchannel has a noticeable effect and heat removal rate can be increased using this technique. The results depict that the arc grooves have a higher heat removal flux compared with rectangular grooves but the latter have a higher coefficient of performance for the case in which grooves are made in the floor and both side walls. Also, it was shown that a grooved microchannel with higher wall thickness and lower mass flow rate of cooling water has a higher heat removal flux and coefficient of performance compared with a simple microchannel with minimum wall thickness. Effect of various sizes and distances of the floor grooves was determined, and the cases for maximum heat removal rate and coefficient of performance for both rectangular and arc grooves were obtained.


2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Nik Ahmad Faiz Nik Mazlam ◽  
Normah Mohd-Ghazali ◽  
Thierry Mare ◽  
Patrice Estelle ◽  
Salma Halelfadl

The microchannel heat sink (MCHS) has been established as an effective heat removal system in electronic chip packaging. With increasing power demand, research has advanced beyond the conventional coolants of air and water towards nanofluids with their enhanced heat transfer capabilities. This research had been carried out on the optimization of the thermal and hydrodynamic performance of a rectangular microchannel heat sink (MCHS) cooled with carbon nanotube (CNT) nanofluid, a coolant that has recently been discovered with improved thermal conductivity. Unlike the common nanofluids with spherical particles, nanotubes generally come in cylindrical structure characterized with different aspect ratios. A volume concentration of 0.1% of the CNT nanofluid is used here; the nanotubes have an average diameter and length of 9.2 nm and 1.5 mm respectively. The nanofluid has a density of 1800 kg/m3 with carbon purity 90% by weight having lignin as the surfactant. The approach used for the optimization process is based on the thermal resistance model and it is analyzed by using the non-dominated sorting multi-objective genetic algorithm. Optimized outcomes include the channel aspect ratio and the channel wall ratio at the optimal values of thermal resistance and pumping power. The optimized results show that, at high operating temperature of 40°C the use of CNT nanofluid reduces the total thermal resistance by 3% compared to at 20°C and consequently improve the thermal performance of the fluid. In terms of the hydrodynamic performance, the pumping power is also being reduced significantly by 35% at 40°C compared to the lower operating temperature.  


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 647 ◽  
Author(s):  
Ravindra Jilte ◽  
Mohammad H. Ahmadi ◽  
Ravinder Kumar ◽  
Vilas Kalamkar ◽  
Amirhosein Mosavi

Heat rejection from electronic devices such as processors necessitates a high heat removal rate. The present study focuses on liquid-cooled novel heat sink geometry made from four channels (width 4 mm and depth 3.5 mm) configured in a concentric shape with alternate flow passages (slot of 3 mm gap). In this study, the cooling performance of the heat sink was tested under simulated controlled conditions.The lower bottom surface of the heat sink was heated at a constant heat flux condition based on dissipated power of 50 W and 70 W. The computations were carried out for different volume fractions of nanoparticles, namely 0.5% to 5%, and water as base fluid at a flow rate of 30 to 180 mL/min. The results showed a higher rate of heat rejection from the nanofluid cooled heat sink compared with water. The enhancement in performance was analyzed with the help of a temperature difference of nanofluid outlet temperature and water outlet temperature under similar operating conditions. The enhancement was ~2% for 0.5% volume fraction nanofluids and ~17% for a 5% volume fraction.


Author(s):  
Gary L. Solbrekken ◽  
Kazuaki Yazawa ◽  
Avram Bar-Cohen

It is well established that the power dissipation for electronic components is increasing. At the same time, high performance portable equipment with volume, weight, and power limitations are gaining widespread acceptance in the marketplace. The combination of the above conditions requires thermal solutions that are high performance and yet small, light, and power efficient. This paper explores the possibility of using thermoelectric (TE) refrigeration as an integrated solution for portable electronic equipment accounting for heat sink and interface material thermal resistances. The current study shows that TE refrigeration can indeed have a benefit over using just a heat sink. Performance maps illustrating where TE refrigeration offers an advantage over an air-cooled heat sink are created for a parametric range of CPU heat flows, heat sink thermal resistances, and TE material properties. During the course of the study, it was found that setting the TE operating current based on minimizing the CPU temperature (Tj), as opposed to maximizing the amount of heat pumping, significantly reduces Tj. For the baseline case studied, a reduction of 20–30°C was demonstrated over a range of CPU heat dissipation. The parametric studies also illustrate that management of the heat sink thermal resistance appears to be more critical than the CPU/TE interfacial thermal resistance. However, setting the TE current based on a minimum Tj as opposed to maximum heat pumping reduces the system sensitivity to the heat sink thermal resistance.


Author(s):  
Afzal Husain ◽  
Mohd Ariz ◽  
Nasser A. Al-Azri ◽  
Nabeel Z. H. Al-Rawahi ◽  
Mohd. Z. Ansari

The increase in the CPV temperature significantly reduces the efficiency of CPV system. To maintain the CPV temperature under a permissible limit and to utilize the unused heat from the CPVs, an efficient cooling and transportation of coolant is necessary in the system. The present study proposes a new design of hybrid jet impingements/microchannels heat sink with pillars for cooling densely packed PV cells under high concentration. A three-dimensional numerical model was constructed to investigate the thermal performance under steady state, incompressible and laminar flow. A constant heat flux was applied at the base of the substrate to imitate heated CPV surface. The effect of two dimensionless variables, i.e., ratios of standoff (distance from the nozzle exit to impingement surface) to jet diameter and jet pitch to jet diameter was investigated at several flow conditions. The performance of hybrid heat sink was investigated in terms of heat transfer coefficient, pressure-drop, overall thermal resistance and pumping power. The characteristic relationship between the overall thermal resistance and the pumping power was presented which showed an optimum design corresponding to S/Dj = 12 having lower overall thermal resistance and lower pumping power.


Author(s):  
Jingru Zhang ◽  
Yogesh Jaluria

In this paper, single phase incompressible liquid flow in a new microchannel heat sink design, which includes flow bifurcation, is studied experimentally and numerically. The experimental setup and device fabrication are briefly explained. The experimental results are presented with uncertainty in the measurements. The numerical model is based on a commercial code and is validated by experimental results with the same initial and boundary conditions. Numerical results with both constant fluid properties and variable properties are compared with the experimental data. The thermal-hydraulic performance of the new design is investigated. The effects of the resulting fluid flow and the geometry on the thermal resistance of the system are discussed.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000434-000439
Author(s):  
V. Ganescu ◽  
A. Pascu

This study reiterates the fact that revolutionary heat sink geometries, materials and overall exponentially higher performing alternatives are continuously and highly needed as applied to the air cooling of a typical computer system microprocessor. Attention was focused on forced convection regimes of operation and from a system level approach. Minor improvements in the performance of air cooled microprocessor heat sinks via typical small design improvements are discussed. Laminar convection and constant heat dissipation were looked at. The CFD simulations exemplified were completed for several power levels and ambient air characterized by a Pr = 0.71. The numerical results presented coincided in large with the experimentally derived documented data. In conclusion, the authors stress the fact that leading-edge alternatives in air-cooled heat removal of such applications are imperiously necessary.


Author(s):  
Avadhesh K. Sharma ◽  
Mayank Modak ◽  
Santosh K. Sahu

Impinging jet surface cooling is being used in many industrial and engineering applications due to their higher heat removal rate. Jet impingement is one of the methods to cool hot surfaces, especially in textile, metal and electronic industries. Due to high heat removal rate the jet impingement cooling of the hot surfaces is being used in nuclear industries. During the loss of coolant accidents (LOCA) in nuclear power plant, an emergency core cooling system (ECCS) cool the cluster of clad tubes using consisting of fuel rods. The usual water flow within a reactor core is bottom to top, parallel to the fuel rods. When a hot surface quenched at very high temperature using a jet of cold fluid, during the quenching the initial heat transfer is limited by film boiling. The effective cooling takes place only after the surface temperature is below the leidenfrost temperature. In the present work an experimental investigation has been carried out to analyze the rewetting phenomenon of a hot vertical stainless steel foil by circular impinging jets of pure water and Al2O3–water nanofluids. The rewetting time and rewetting velocity in the form of dimensionless number (Peclet number) obtained from the thermal images obtained from infrared thermal imaging camera (A655sc, FLIR System). Experiments are performed for different Reynolds number (Re = 5000, 8000), and Al2O3–water nanofluids concentration (Φ = 0.15%, 0.6%)


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