A three-dimensional thermal analysis for cooling a square Light Emitting Diode by Multiwalled Carbon Nanotube-nanofluid-filled in a rectangular microchannel

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110599
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammed A. Almeshaal ◽  
Khalil Hajlaoui
Keyword(s):  
Heat Sink ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Engine Oil ◽  
Inlet Temperature ◽  
Rectangular Microchannel ◽  
Light Emitting

The aim of this paper is to ensure proper thermal management in order to remove and dissipate the heat produced by a square Light Emitting Diode (LED), as well as to ensure stable and safe operation by reducing the junction temperature. For this, we developed a three-dimensional code, time-dependent that solves the systems of equations for the mass, momentum, and energy using Comsol Multiphysics. After validation of this numerical 3D code, the thermal performance of a LED cooling system with three nanofluids such as MWCNT-Water, MWCNT-Ethylene Glycol, and MWCNT-Engine oil is studied numerically into account of aggregation effect. Several parameters such as: the power of the LED lamp, the inlet temperature and velocity of nanofluid, the length of the heat sink, and the length of the microchannel have been varied in order to find an optimal condition allowing a good heat dissipation from the LED chip to the heat sink. It was concluded that the use of MWCNT-Water in the microchannel is the best nanofluid that can cool the heat sink. In addition, the increase of velocity inlet of the coolant in the microchannel, the length of the heat sink, and the microchannel length while the decrease of the inlet temperature of nanofluid in the microchannel are an important factors allowing the decrease of the junction temperature of the square LED lamp.

Numerical Analysis for Thermal Performance of High Power Multi-Chip LED Packaging

2010 ◽  
Vol 139-141 ◽  
pp. 1433-1437
Author(s):  
Kai Lin Pan ◽  
Jiao Pin Wang ◽  
Jing Liu ◽  
Guo Tao Ren
Keyword(s):  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Light Emitting ◽  
Die Attach ◽  
Dissipation Model ◽  
Key Issues

Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.

Thermal Analysis of High Power Light Emitting Diodes Package

2011 ◽  
Vol 687 ◽  
pp. 215-221
Author(s):  
Yuan Yuan Han ◽  
Hong Guo ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ke Chu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
High Power ◽  
Thermal Field ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Convective Heat Exchange ◽  
Input Power ◽  
Junction Temperature ◽  
Original Structure ◽  
Light Emitting

With increasing of the input power of the chips in light emitting diode (LED)， the thermal accumulation of LEDs package increases. Therefore solving the heat issue has become a precondition of high power LED application. In this paper, finite element method was used to analyze the thermal field of high power LEDs. The effect of the heatsink structure on the junction temperature was also investigated. The results show that the temperature of the chip is 95.8°C which is the highest, and it meets the requirement. The conductivity of each component affects the thermal resistance. Convective heat exchange is connected with the heat dissipation area. In the original structure of LEDs package the heat convected through the substrate is the highest, accounting for 92.58%. Three heatsinks with fin structure are designed to decrease the junction temperature of the LEDs package.

Thermal Performance Evaluation and Economic Analysis of LED Integrated with Thermoelectric Cooler Package

2011 ◽  
Vol 216 ◽  
pp. 106-110 ◽  
Author(s):  
Hong Qin ◽  
Da Liang Zhong ◽  
Chang Hong Wang
Keyword(s):  
Economic Analysis ◽  
Thermal Performance ◽  
Power Dissipation ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Vital Role ◽  
Junction Temperature ◽  
Total Power ◽  
Thermoelectric Cooler ◽  
Light Emitting

Thermal management is an important issue for light emitting diodes’ utilization. For high power light emitting diode (LED), active heat dissipation method plays a vital role. As a new cooling device, thermoelectric cooler (TEC) is applied in LED packaging for the precisely temperature controlled advantage. In order to evaluate the thermal performance of the TEC packaging designs in LED, experimental measurement is used to assess the chip’s junction temperature of three different cooling models, which include the heatsink model, the heatsink and fan model and the TEC, heatsink and fan model. Based on the research, it is better to apply TEC cooling methods with the power dissipation of LED less than 35 W and the wind speed is 3.6 m/s. However, the power dissipation of TEC itself plays a vital role of the total power dissipation of LED packaging. The results of economic analysis shows that the LED integrated with TEC package achieves 22.34% and 44.73% electric energy saving under the condition of 20 W and 30 W power dissipation of the LED chip contrasts to the fluorescent lamp, but sacrifices 2.71% electric power under the condition of 10 W power dissipation of the LED chip.

scholarly journals Thermal Performance of LED Filament in Flip-Chip Packaging Manufactured for Different Correlated Color Temperature

2021 ◽  
Vol 11 (19) ◽  
pp. 8844
Author(s):  
He Jiang ◽  
Jiming Sa ◽  
Cong Fan ◽  
Yiwen Zhou ◽  
Hanwen Gu ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Color Difference ◽  
Junction Temperature ◽  
Color Temperature ◽  
Constant Current ◽  
Light Emitting ◽  
Flip Chip Packaging

The effect of correlated color temperature (CCT) on the thermal performance of light emitting diode (LED) filament in flip-chip packaging was investigated in detail. Two filaments with different lengths were selected as the research object, and the thermal resistance of filaments under three CCT (2200 K, 2400 K, 2700 K) were studied. The optical properties and thermal parameters of the two groups of filaments were measured, and the results were analyzed combined with the color coordinate. The experimental results show that thermal properties of LED filaments is closely related to CCT. Under constant current condition, junction temperature decreases with the increase of color difference. With the change of phosphor glue and phosphorus powder ratio, the color temperature of LED filament also changes. In the filaments with the same chip structure and packaging mechanism, the higher the proportion of red phosphorescent powder, the worse the heat dissipation performance of the filament. These results show that in the design and manufacture of LED filament, it is helpful to control the CCT of LED filament under the premise of meeting the use requirements.

Thermal Performance of Domestic Replacement A19 LED Lighting Products

2016 ◽  
Author(s):  
Thomas Storey ◽  
Robin Rackerby ◽  
Heather Dillon ◽  
Lydia Gingerich
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Research Process ◽  
Light Emitting ◽  
Led Lighting ◽  
Proper Design ◽  
The Cost

In an effort to create a Light Emitting Diode (LED) lighting system that is as efficient as possible, the heat dissipation system must be accurately measured for proper design and operation. Because LED lighting technology is new, little optimization has been performed on typical cooling system required for most A19 replacement products. This paper describes the research process for evaluating the thermal performance of over 15 LED lighting products and compares their performance to traditional lighting sources, namely incandescent and compact fluorescent (CFL). This process uses radiation and convection to model typical cooling mechanisms for domestic A19 type replacement LED products. The A19 products selected for this investigation had input wattages ranging between 7 to 60 Watts, with outputs ranging from 450 to 1100 lumens. The average LED tested dissipated 43% (± 5%) of the total heat generated in the lighting product through the heat exchanger. The best thermal performance was observed in an LED product that dissipated approximately 58% of the total product heat through the heat exchanger. Results indicate that significant improvements to the current LED heat exchanger designs are possible, which will help lower the cost of future LED products, improve performance, and reduce the environmental footprint of the products.

LED Heat Dissipation Analysis Using Composite Based Cylindrical Slug

2014 ◽  
Vol 893 ◽  
pp. 803-806 ◽  
Author(s):  
Zaliman Sauli ◽  
Rajendaran Vairavan ◽  
Vithyacharan Retnasamy
Keyword(s):  
Natural Convection ◽  
Heat Dissipation ◽  
Simulation Analysis ◽  
Light Emitting Diode ◽  
Input Power ◽  
Junction Temperature ◽  
Simulation Platform ◽  
Single Chip ◽  
Light Emitting ◽  
Convection Condition

The optical efficacy and reliability of light emitting diode is extensively influenced by the operating junction temperature of the LED. Therefore, the evaluation of junction temperature is significant. This paper reports a simulation analysis on the heat dissipation of single chip LED package with based material, copper diamond (Cu/Dia) cylindrical heat slug.Ansys version 11 was utilized as the simulation platform. The junction temperature and stress of the LED chip under natural convection condition were evaluated with varied input power of 0.1 W, 0.5 W and 1 W. Results indicated the maximum junction temperature of LED chip was attained at input power of 1 W.

Thermal Analyses of LED Light Bars and Backlight Modules

2016 ◽  
Vol 33 (3) ◽  
pp. 331-339 ◽  
Author(s):  
M.-Y. Tsai ◽  
C.-Y. Tang ◽  
C.-E. Zheng ◽  
Y.-Y. Tsai ◽  
C.-H. Chen
Keyword(s):  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Thermal Analyses ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Thermal Interface Materials ◽  
Light Emitting ◽  
Led Light ◽  
The One ◽  
Interface Materials

AbstractThe effects of various parameters, such as thermal properties of substrates, thermal interface materials (TIMs) and heat sinks on the thermal performance of the light emitting diode (LED) light bars and backlight module are investigated experimentally and numerically in terms of junction temperature (Tj) and thermal resistances from junction to air (Rj-a). The results show that the measured Rj-a of the light bars by powering-on five LEDs in the test is different from one by powering-on only one LED, resulting from the extra heat coming from the adjacent LED packages affecting the Tj for the case of powering-on five LEDs. For the modules, Rj-a is significantly reduced by using the heat sinks for all backlight modules, and aluminum and iron heat sinks do not show any obvious difference in heat dissipation along with any substrates and TIMs. Furthermore, both experimental and simulation results show that the thermal conductivity of the substrates are more important and dominant than TIM and heat sink for the Rj-a of the backlight modules concerned, and also demonstrate that the thermal field for the local model can represent the one in full-scale backlight module.

Application of Micro-Tube Water-Cooling Device for the Improvement of Heat Management in Mixed White Light Emitting Diode Modules

2011 ◽  
Vol 308-310 ◽  
pp. 2422-2427 ◽  
Author(s):  
Maw Tyan Sheen ◽  
Ming Der Jean ◽  
Yu Tsun Lai
Keyword(s):  
Thermal Management ◽  
White Light ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Thermal Dissipation ◽  
Water Cooling ◽  
Cooling Device ◽  
Heat Management ◽  
Light Emitting

This paper introduces a module using the RGB-based LED design to improve the thermal management of a mixied white light LED and describes a system for heat dissipation in illuminated, high-power LED arrays. Mixed light LEDs can be produced by combining appropriate amounts of light from the red, green and blue LEDs in an array. A LED cooling system, using a micro- tube water-cooling device, was fabricated. Recycling water in the system, gave more efficient convection and the heat created by the LEDs was easily removed, in the experiments. It was shown that micro-tube water-cooling systems rendered an improvement in thermal management that effectively decreases the thermal resistance and provides very good thermal dissipation. Furthermore, the results of experiment and simulation demonstrated that a micro-tube water-cooling system is very effective in heat dissipation in LEDs and the fabrication of practical micro-water tube cooling devices for mixing light LEDs was feasible and useful

Improved lateral heat spreading performance for polyvinylidene fluoride composite film comprising silver nanowire in light-emitting diode

RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35884-35891 ◽  
Author(s):  
Zhao Li ◽  
Li Zhang ◽  
Rong Qi ◽  
Fan Xie ◽  
Shuhua Qi
Keyword(s):  
Heat Sink ◽  
Polyvinylidene Fluoride ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Silver Nanowire ◽  
Transfer Property ◽  
Light Emitting ◽  
Thermal Transfer ◽  
Heat Spreading ◽  
Lateral Heat

Silver nanowire (AgNW) attracts great attention as a heat dissipation material due to its excellent thermal transfer property which exceeds most traditional heat sink materials.

Advanced Natural Convection Cooling Designs for Light-Emitting Diode Bulb Systems

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
James Petroski
Keyword(s):  
Natural Convection ◽  
Heat Sink ◽  
Energy Savings ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Point Of View ◽  
Light Bulb ◽  
Light Emitting ◽  
Size And Shape ◽  
Liquid Cooling System

The movement to light-emitting diode (LED) lighting systems worldwide is accelerating quickly as energy savings and reduction in hazardous materials increase in importance. Government regulations and rapidly lowering prices help to further this trend. Today's strong drive is to replace light bulbs of common outputs (60 W, 75 W, and 100 W) without resorting to compact fluorescent (CFL) bulbs containing mercury while maintaining the standard industry bulb size and shape referred to as A19. For many bulb designs, this A19 size and shape restriction forces a small heat sink which is barely capable of dissipating heat for 60 W equivalent LED bulbs with natural convection for today's LED efficacies. 75 W and 100 W equivalent bulbs require larger sizes, some method of forced cooling, or some unusual liquid cooling system; generally none of these approaches are desirable for light bulbs from a consumer point of view. Thus, there is interest in developing natural convection cooled A19 light bulb designs for LEDs that cool far more effectively than today's current designs. Current A19 size heat sink designs typically have thermal resistances of 5–7 °C/W. This paper presents designs utilizing the effects of chimney cooling, well developed for other fields that reduce heat sink resistances by significant amounts while meeting all other requirements for bulb system design. Numerical studies and test data show performance of 3–4 °C/W for various orientations including methods for keeping the chimney partially active in horizontal orientations. Significant parameters are also studied with effects upon performance. The simulations are in good agreement with the experimental data. Such chimney-based designs are shown to enable 75 W and 100 W equivalent LED light bulb designs critical for faster penetration of LED systems into general lighting applications.

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