scholarly journals Experimental Research on the Behaviour of Heat Pipe Using Graphene Oxide as Working Fluid

2019 ◽  
Vol 8 (2S11) ◽  
pp. 2052-2055
Keyword(s):  
Graphene Oxide ◽  
Heat Pipe ◽  
Electronic Devices ◽  
Vital Role ◽  
Working Fluid ◽  
Main Concern ◽  
Outer Diameter ◽  
Evaporation Zone ◽  
Innovative Techniques ◽  
Day By Day

The liberation of heat from the electronic devices used in the industries, refrigeration and etc. is main concern today. The temperature of the planet earth is being increasing day by day, the generation of heat by the manufacturing industries should be reduced using innovative techniques. Generally a heat exchangers were used to reduce it. In this study, graphene oxide employed as as working fluid to determine the effective thermal conductivity. The working fluid graphene oxide plays vital role in dissipation of heat from the evaporation zone to condensed zone. The experiment setup was done with about 19.1 mm and 21 mm inner and outer diameter, respectively. The length of the heat pipe is 600 mm. The wick material was made up of brass. We observed that the graphene oxide improved thew efficieny by using as working fluid.

Development of a Copper Heat Pipe with Axial Grooves Manufactured Using Wire Electrical Discharge Machining (Wire-EDM)

2015 ◽  
Vol 1120-1121 ◽  
pp. 1325-1329 ◽  
Author(s):  
Felipe B. Nishida ◽  
Larissa S. Marquardt ◽  
Valquíria Y.S. Borges ◽  
Paulo H.D. Santos ◽  
Thiago Antonini Alves
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Average Diameter ◽  
Working Fluid ◽  
Outer Diameter ◽  
Wire Electrical Discharge Machining ◽  
Wire Edm ◽  
Heat Loads

In this research, a heat pipe with grooves was experimentally analyzed for the application in thermal management of electronic packaging. The heat pipe was produced by a copper tube with an outer diameter of 9.45 mm, length of 205 mm, and capillary structure composed by axial grooves with average diameter of 220 μm. The grooves were manufactured using wire electrical discharge machining (wire-EDM). The working fluid used was de-ionized water. The condenser was cooled by air forced convection and the evaporator was heated using an electrical resistor. This heat pipe was tested horizontally to increasing heat loads varying from 5 to 15 W. The experimental results showed that the heat pipe worked successfully.

The Performance Enhancement of a Heat Pipe for Power Electronics Cooling With a Partially Applied Hybrid Wick

2017 ◽  
Author(s):  
Joon Hong Boo ◽  
Hyun Gon Kim ◽  
Chang Woo Han
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Performance Enhancement ◽  
Electronics Cooling ◽  
Typical Result ◽  
Working Fluid ◽  
Outer Diameter ◽  
Thermal Loads ◽  
Fine Mesh ◽  
Wire Screen

A series of experiments was conducted to investigate the performance characteristics of a heat pipe with a hybrid wick that combined grooves and a wire screen. The heat pipe in this study was designed primarily for the cooling of high-density power electronic elements such as IGBTs, and it had tiny triangular grooves along its entire length. The container was a copper tube which had an outer diameter of 19 mm and length of 0.8 m, and the working fluid was water. To lower the thermal resistance against increased thermal loads, a higher performance was desired for the heat pipe, without changing the external dimensions. A fine mesh wire screen was partially applied to the evaporator to enhance the heat transfer performance. The hybrid wick heat pipe was tested and analyzed from the viewpoints of thermal resistance, effective thermal conductance, and operating temperature. For a 1.6 kW effective thermal load, as a typical result, the heat pipe with the hybrid wick exhibited a 70 % decrease in thermal resistance compared to that with a groove wick only. The paper includes results for various thermal loads and fluid charges. The results herein can be utilized in applications that require an intensive enhancement in heat pipe performance.

Improvement of Heat Transfer Performance of Loop Heat Pipe for Electronic Devices

2011 ◽  
Author(s):  
Tomonao Takamatsu ◽  
Katsumi Hisano ◽  
Hideo Iwasaki
Keyword(s):  
Heat Pipe ◽  
Heat Transport ◽  
Thermal Energy ◽  
Heat Load ◽  
Cooling System ◽  
Electronic Devices ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Reserve Area ◽  
Heat Transport Capability

In this paper is presented the results on performance of the cooling model using Loop Heat Pipe (LHP) system. In recent years, ever-ending demand of high performance CPU led to a rapid increase in the amount of heat dissipation. Consequently, thermal designing of electronic devices need to consider some suitable approach to achieve high cooling performance in limited space. Heat Pipe concept is expected to serve as an effective cooling system for laptop PC, however, it suffered from some problems as follows. The heat transport capability of conventional Heat Pipe decreases with the reduction in its diameter or increase in its length. Therefore, in order to use it as cooling system for future electronic devices, the above-mentioned limitations need to be removed. Because of the operating principle, the LHP system is capable of transferring larger amount of heat than conventional heat pipes. However, most of the LHP systems suffered from some problems like the necessity of installing check valves and reservoirs to avoid occurrence of counter flow. Therefore, we developed a simple LHP system to install it on electronic devices. Under the present experimental condition (the working fluid was water), by keeping the inside diameter of liquid and vapor line equal to 2mm, and the distance between evaporator and condenser equal to 200mm, it was possible to transport more than 85W of thermal energy. The thickness of evaporator was about 5mm although it included a structure to serve the purpose of controlling vapor flow direction inside it. Successful operation of this system at inclined position and its restart capability are confirmed experimentally. In order to make the internal water location visible, the present LHP system is reconstructed using transparent material. In addition, to estimate the limit of heat transport capability of the present LHP system using this thin evaporator, the air cooling system is replaced by liquid cooling one for condensing device. Then this transparent LHP system could transport more than 100W of thermal energy. However, the growth of bubbles in the reserve area with the increase in heat load observed experimentally led to an understanding that in order to achieve stable operation of the LHP system under high heat load condition, it is very much essential to keep enough water in the reserve area and avoid blocking the inlet with bubbles formation.

scholarly journals Experimental investigation of a heat pipe heat exchanger for heat recovery

2018 ◽  
Vol 45 ◽  
pp. 00012
Author(s):  
Anna Bryszewska-Mazurek ◽  
Wojciech Mazurek
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Working Fluid ◽  
Air Velocity ◽  
Condensation Zone ◽  
Evaporation Zone ◽  
Air Stream ◽  
Face Velocity ◽  
Pipe Heat

An air-to-air heat pipe heat exchanger has been designed, constructed and tested. Gravity-assisted wickless heat pipes (thermosiphons) were used to transfer heat from one air stream to another air stream, with a low temperature difference. A thermosiphon heat exchanger has its evaporation zone below the condensation zone. Heat pipes allow keeping a more uniform temperature in the heat transfer area. The heat exchanger consists of 20 copper tubes with circular copper fins on their outer surface. The tubes were arranged in a row and the air passed across the pipes. R245fa was used as a working fluid in the thermosiphons. Each heat pipe had a 40 cm evaporation section, a 20 cm adiabatic section and a 40 cm condensation section. The thermosiphon heat exchanger has been tested in different conditions of air stream parameters (flows, temperatures and humidity). The air face velocity ranged from 1,0 m/s to 4,0 m/s. The maximum thermal efficiency of the thermosiphon heat exchanger was between 26÷40%, depending on the air velocity. The freezing of moisture from indoor air was observed when the cold air temperature was below - 13°C.

scholarly journals Heat transfer analysis of looped micro heat pipes with graphene oxide Nanofluid for Li-ion battery

2020 ◽  
pp. 218-218
Author(s):  
Prabu Manikanda ◽  
G. Sureshkannan ◽  
S. Suresh ◽  
Kumar Senthil
Keyword(s):  
Heat Transfer ◽  
Graphene Oxide ◽  
Heat Pipe ◽  
Heat Transfer Analysis ◽  
New Combination ◽  
Working Fluid ◽  
Li Ion Batteries ◽  
Li Ion Battery ◽  
Micro Heat Pipe ◽  
Li Ion

Li-ion batteries play a vital role in electromechanical devices. The heat load on such batteries varies with time and application which falls as high-temperature rise and it causes severe damages on a device and reduces the life cycle. It will be a big challenge in future decades of electronic devices and the electric car revolution. To overcome such difficulties, this work is considered for thermal management of small Li-ion batteries to check the possibilities through the micro heat pipe. Due to the high impact of Nanotechnology in heat transfer science, Acetone, De-ionized water, and Tetrahydrofuran fluids are blended with Graphene Oxide Nanoparticles to prepare the Nanofluids by ultrasonic method. Here, Tetrahydrofuran is a new combination of Nano-working fluid and not addressed by pre-researchers. Tetrahydrofuran-graphene Nanofluid provides 61% of improved thermal conductivity than the other two fluids which accelerates the heat transfer rate with reduced thermal resistance in the range of 0.09- 0.640C/W. To validate the experimental results, a real-time study has been done on Li-ion batteries for a day and ensured the reduction of overheat issues. Hence, the present work will support the Li-ion battery to work in an optimal temperature range in a new way of micro heat pipe with Nanofluid.

scholarly journals Experimental investigations and optimization of process parameters of meshed-wick heat pipe

2020 ◽  
Vol 184 ◽  
pp. 01026 ◽  
Author(s):  
B.Ch Nookaraju ◽  
B. Hemanth Sai ◽  
K.V.N.S Himakar ◽  
N. Limba Reddy ◽  
N Sateesh
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Working Fluid ◽  
Outer Diameter ◽  
Cylindrical Shape ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Screen Mesh

Heat pipes are used to transfer heat, which are hollow cylindrical shape device filled with small amount of working fluid, which can change its phase. The rate of heat transfer in heat pipes compared to normal heat exchanging devices is more. Depending on the applications of heat transfer various heat pipes are being designed. Methanol fluid is used with 50% fill ratio. It is made of copper with outer diameter of 15.88mm and inner diameter of 14.88mm. It consists of a screen mesh made of copper powder inside it with thickness of 0.5mm. Due to heat input methanol changes its phase from liquid to vapor. The vapor loses its heat and changes its phase back to liquid in the condenser. At the condenser section the vapour gives up it heat and changes its phase from vapour to liquid. The screen mesh assists the flow of condensed working fluid through capillary action. Optimized the results by “Taguchi method” using “Minitab software”. The Thermal analysis was done with the optimum conditions, which were obtained as a result from the optimization method by Ansys Fluent software. Then finally compared the thermal parameters obtained from experiments with the Thermal analysis result. It is found the maximum heat transfer rate is optimized using meshed wick heat pipe conditions.

Parametric Behaviour of Closed Loop Pulsating Heat Pipe in the Presence of Water As a Working Fluid

2019 ◽  
Author(s):  
Nagendra P. Yadav ◽  
Madhuri ◽  
Anil Kumar
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Integrated Circuit ◽  
Closed Loop ◽  
Electronic Devices ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Power Inputs ◽  
Variable Power ◽  
Circuit Technology

Abstract This paper focuses on the parametric behavior of a closed loop pulsating heat pipe in the presence of water as a working fluid. The experimental study was done in the presence of different vacuum pressures inside the heat pipe with 50 percent filling ratio. The temperature was measured through the DAQ system with help of Lab VIEW 15.1 software at 12 locations of heat pipe at variable power inputs (10W–70W). Thermal resistance and variation of temperature are used to predict the performance of the heat pipe. Thermal resistance of heat pipe decreases with decrease in vacuum pressure inside the heat pipe. This work is useful for the transfer of heat of electronic devices and integrated circuit technology due to the high coefficient of convective heat transfer in the presence of phase change of working fluid inside the heat pipe.

scholarly journals Experimental research of capillary structure technologies for heat pipes

2020 ◽  
Vol 42 ◽  
pp. e48189
Author(s):  
Larissa Krambeck ◽  
Guilherme Antonio Bartmeyer ◽  
Davi Fusão ◽  
Paulo Henrique Dias dos Santos ◽  
Thiago Antonini Alves
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Electrical Discharge Machining ◽  
Heat Pipes ◽  
Working Fluid ◽  
Outer Diameter ◽  
Wire Edm ◽  
Sintering Process ◽  
Capillary Structure ◽  
Heat Loads

This paper presents an experimental study on three different capillary structure technologies of heat pipes for application in the thermal management of electronic packaging. The first capillary structure is that of axial grooves manufactured by wire electrical discharge machining (wire-EDM). The sintering process with copper powder produced the second heat pipe. Finally, a hybrid heat pipe was made by the combination of the two previous methods. The heat pipes were produced using copper tubes with an outer diameter of 9.45 mm and a length of 200 mm, and were tested horizontally at increasing heat loads varying from 5 to 35 W. The working fluid used was distilled water. The experimental results showed that all capillary structures for heat pipes worked successfully, so the studied manufacturing methods are suitable. Nonetheless, the hybrid heat pipe is the best, due to the lowest thermal resistance presented.

Filling ratio optimization for high performance nanoengineered copper-water heat pipes.

2021 ◽  
pp. 1-28
Author(s):  
Ahmed A. Abdulshaheed ◽  
Pengtao Wang ◽  
Guanghan Huang ◽  
Yueyang Zhao ◽  
Chen Li
Keyword(s):  
Heat Pipe ◽  
High Performance ◽  
Oxide Coating ◽  
Filling Ratio ◽  
Working Fluid ◽  
Outer Diameter ◽  
Optimum Configuration ◽  
Copper Water ◽  
Copper Pipe ◽  
Inclination Angles

Abstract This experimental test investigates the effect of filling ratio and inclination angle on the thermal performance of a nanoengineered copper-water heat pipe. A hydrophilic copper oxide coating (CuO) is synthesized and integrated on the inner wall of the evaporation section of the heat pipe. The heat pipe is fabricated from an inner grooved copper pipe with dimensions of 12.7 mm outer diameter, 11 mm inner diameter, and 440 mm length. Ultra-filtered deionized (DI) water is used as working fluid. Four different filling ratios (FR) of DI water 3%, 5%, 10%, and 15% are investigated to determine the optimum configuration. All samples are tested at various inclination angles and working loads. Experimental results show that the optimum filling ratio is the 5% FR, which was indicated by the lowest thermal resistance of 0.019 K/W.

scholarly journals Thermal Performance of Thermosyphons Intended for Evacuated Tube Solar Collector Using Graphene Oxide Nanofluids

2021 ◽  
Vol 1 (1) ◽  
pp. 14-19
Author(s):  
T. Antonini Alves
Keyword(s):  
Graphene Oxide ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Outer Diameter ◽  
Joule Effect ◽  
Running Water ◽  
Glass Tubes ◽  
Evacuated Tube ◽  
Heat Loads ◽  
Adiabatic Section

Vacuum tube solar collectors are composed by two concentric glass tubes with the annular space evacuated. At the inner tube a thermosyphon is placed inside a metallic fin in order to absorb sun’s irradiation and heat running water placed at a manifold. Thermosyphons are passive heat transfer devices that absorb heat at the evaporator region, evaporating the working fluid that reaches the condenser in the form of steam. At the condenser, heat is dissipated to the environment, condensing the working fluid that returns to the evaporator, closing the thermodynamic cycle. In this study, thermosyphons with three different working fluids (5 and 10% graphene oxide nanofluids and distilled water) were built and experimentally tested. The evaporator and the adiabatic section have an outer diameter of 8.33mm and lengths of 1,600mm and 40mm, respectively. The condenser has an outer diameter of 13.40mm and a length of 35mm. The filling ratio used was 50% of the evaporator’s volume. A resistive tape wrapped at the evaporator and connected to a power supply was responsible for heating the working fluid by Joule effect, and water flow rates of 0.50, 0.75, and 1.00L/min were responsible for condensing the working fluid at the condenser. Heat loads of 35, 55, and 75W were applied to the devices and K-type thermocouples were responsible for acquiring temperature data from the thermosyphons, allowing the thermal analysis based in the temperature distribution and thermal resistance for each working fluid. The best working fluid for the conditions proposed, out of the three investigated, was 5% graphene oxide.

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