Thermal Performance Prediction of a Finned Plain-Plate Heat-Pipe for LED Lamp

2011 ◽  
Vol 55-57 ◽  
pp. 2135-2138
Author(s):  
Xu Liang Xie
Keyword(s):  
Thermal Conductivity ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Performance Prediction ◽  
Heat Transfer Performance ◽  
Light Emitting Diode ◽  
Cooling Capacity ◽  
Light Emitting ◽  
Plate Heat ◽  
Inclined Angle

In order to keep the temperature of Light emitting diode (LED) lamp below some limitation, a finned plain-plate heat-pipe was presented and numerically investigated to predict heat transfer performance under natural convection. Two kinds of fin configurations were studied. It is found that 30° is the worst orientation for the fin configuration with the tops of every other two channels covered, while the worst orientation is around 60° for the fin configuration with channel tops opened. The thermal conductivity of fin material only has mild effect on the cooling capacity with 7 % difference when its thermal conductivity varies from 50 to 200 W/(m·k). The latter configuration has better thermal performance than the former at the same orientation, especially at relatively low inclined angle.

Thermal Performance of a Thin Flat Plate Heat Pipe

2009 ◽  
Author(s):  
Wei Qu ◽  
Shijuan Li ◽  
Hongwu Yang
Keyword(s):  
Thermal Conductivity ◽  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Tilt Angle ◽  
Test Results ◽  
Test Setup ◽  
Plate Heat ◽  
Flat Plate Heat Pipe ◽  
Performance Results

A thin flat plate heat pipe (TFPHP) with a new structure of wick is fabricated and tested. The wick is formed by the narrow foils folded, the liquid passage and capillary force is provided by the folded clearance of the foils, the vapor passage is shaped by the periodic holes of the foils. One aluminum TFPHP of 260×60×4 mm3 size is made and the test setup is established. The test results show that the spreader has good performance as, at the horizontal state, the power transferred can reach 18.5W, the corresponding thermal conductivity is 838W/(m·°C). For different tilt angle, we have the performance results. The effects of parameters to the performance are discussed. The spreader is significant for the spreading of point power.

Experimental Investigation on Heat Transfer Performance of a Flat Plate Heat Pipe With MWCNTS-Acetone Nanofluid

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Xiaohong Hao ◽  
Bei Peng ◽  
Yi Chen ◽  
Gongnan Xie
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Aspect Ratio ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Mass Concentration ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Plate Heat ◽  
Flat Plate Heat Pipe

This paper experimentally investigates how different mass concentration and aspect ratio multiwall carbon nanotubes (MWCNTs) acetone nanofluid affects the heat transfer performance of a flat plate heat pipe (FPHP). Different mass concentration and aspect ratio MWCNTs-acetone nanofluids are prepared without any surfactants or additives using the two-step method. Aspect ratios of MWCNTs are 666 (M1) and 200 (M2), respectively, and their according mass concentrations are 0.002, 0.005, 0.01, and 0.015 wt. %, respectively. The thermal resistance and wall temperature of the FPHP are experimentally obtained when the above-mentioned nanofluids are used as working fluid. The results showed that different mass concentration affects the heat transfer performance, therefore, there is an optimal MWCNTs-acetone nanofluid mass concentration (about 0.005wt. %). Also, the results showed that the thermal resistances of the FPHP with M1-acetone nanofluid (0.005 wt. %) and M2-acetone nanofluid (0.005 wt. %) are reduced 40% and 16%, respectively. Based on the above experimental phenomenon, this paper discusses the reasons for enhancement and decrement of heat transfer performance of the different mass concentration. For the M1-acetone nanofluid, the investigated FPHP has a thermal resistance of 0.26 °C/W and effective thermal conductivity 3212 W/m k at a heat input of 160 W. For the M2-acetone nanofluid, the investigated FPHP has a thermal resistance of 0.33 °C/W and effective thermal conductivity 2556 W/m k at a heat input of 150 W. The nanofluid FPHP investigated here provides a new approach in designing a high efficient next generation heat pipe cooling devices.

Thermal conduction characteristics of silicone composites including ultrasonic-treated graphite

2021 ◽  
pp. 002199832110595
Author(s):  
Weontae Oh ◽  
Jong-Seong Bae ◽  
Hyoung-Seok Moon
Keyword(s):  
Thermal Conductivity ◽  
Ultrasonic Treatment ◽  
Thermal Conduction ◽  
Light Emitting Diode ◽  
Thermal Interface Material ◽  
Ultrasonic Power ◽  
Lighting System ◽  
Thermal Interface ◽  
Light Emitting ◽  
Inorganic Oxides

The microstructural change of graphite was studied after ultrasonic treatment of the graphite. When the graphite solution was treated with varying ultrasonic power and time, the microstructure changed gradually, and accordingly, the thermal conductivity characteristics of the composite containing the as-treated graphite was also different with each other. Thermal conductivity showed the best result in the silicone composite containing graphite prepared under the optimum condition of ultrasonic treatment, and the thermal conductivity of the composite improved proportionally along with the particle size of graphite. When the silicone composite was prepared by using a mixture of inorganic oxides and graphite rather than graphite alone, the thermal conductivity of the silicone composite was further increased. A silicone composite containing graphite was used for LED (light emitting diode) lighting system as a thermal interface material (TIM), and the temperature elevation due to heat generated, while the lighting was actually operated, was analyzed.

scholarly journals Thermal performance of heat sink with fluid pockets for high power light emitting diode

2017 ◽  
Vol 14 (4) ◽  
pp. 4846-4862
Author(s):  
Sangmesh ◽  
◽  
Gopalakrishna Keshava Narayana ◽  
Manjunath Shiraganhalli Honnaiah ◽  
Krishna Venkatesh ◽  
...  
Keyword(s):  
Thermal Performance ◽  
High Power ◽  
Heat Sink ◽  
Light Emitting Diode ◽  
Light Emitting

Thermal performance of a flat-plate heat-pipe collector array

Solar Energy ◽  
1993 ◽  
Vol 50 (6) ◽  
pp. 491-498 ◽  
Author(s):  
T.Y. Bong ◽  
K.C. Ng ◽  
H. Bao
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Plate Heat ◽  
Flat Plate Heat Pipe

Experimental Investigation of Thermal Conduction Performance on Silicon-Based Micro Flat Heat Pipe

2015 ◽  
Vol 645-646 ◽  
pp. 1032-1037
Author(s):  
Cong Ming Li ◽  
Yi Luo ◽  
Chuan Peng Zhou ◽  
Liang Liang Zou ◽  
Xiao Dong Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Pipe ◽  
Effective Thermal Conductivity ◽  
Thermal Performance ◽  
Axial Direction ◽  
Filling Ratio ◽  
Parallel Structure ◽  
Working Fluid ◽  
Vacuum Degree ◽  
Structure Dimension

There are several factors that affect heat transfer of heat pipe, for example, structure dimension, filling ratio and vacuum degree of charging. This paper studied the thermal conductivity of micro flat heat pipes (MFHPs) with different structure dimension and with different filling ratio, when the charging vacuum degree of MFHP was decided. When electric power was 2W or 4W, MFHPs with parallel grooves and nonparallel grooves, charged by working fluid with different filling ratio, were carried out. And the filling ratio is 30%, 40% and 50%, respectively. The better thermal performance of MFHP can be evaluated by lower thermal resistance and higher effective thermal conductivity. The experiment results show that MFHP has the highest effective thermal conductivity when the filling ratio is 40%; and the thermal performance of MFHP with nonparallel structure in axial direction is better than that of MFHP with parallel structure.

Thermal Performance of a Light Emitting Diode Light Engine for a Multipurpose Automotive Exterior Lighting System With Competing Board Technologies

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Umut Zeynep Uras ◽  
Mehmet Arık ◽  
Enes Tamdoğan
Keyword(s):  
Thermal Performance ◽  
Computational Models ◽  
Printed Circuit Boards ◽  
Light Emitting Diode ◽  
Ambient Conditions ◽  
Vapor Chamber ◽  
Metal Core ◽  
Light Emitting ◽  
Lighting Systems ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems replacing old-fashioned incandescent and halogen systems. LEDs are preferable for automobile lighting applications due to its numerous advantages such as low power consumption and precise optical control. Although these solid state lighting (SSL) products offer unique advantages, thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double-sided FR4-based printed circuit boards (PCBs) are utilized for both driver electronic components and LEDs. In fact, this approach will be a leading trend for advanced internet of things applications embedded LED systems in the near future. Therefore, automotive lighting systems are already facing with tight-packaging issues. To evaluate thermal issues, a hybrid study of experimental and computational models is developed to determine the local temperature distribution on both sides of a three-purpose automotive light engine for three different PCB approaches having different materials but the same geometry. Both results showed that FR4 PCB has a temperature gradient (TMaxBoard to TAmbient) of over 63 °C. Moreover, a number of local hotspots occurred over FR4 PCB due to low thermal conductivity. Later, a metal core PCB is investigated to abate local hot spots. A further study has been performed with an advanced heat spreader board based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4-based boards with the advanced vapor chamber substrate is observed. In addition to superior thermal performance, a significant amount of lumen extraction in excess of 15% is measured, and a higher reliability rate is expected.

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