scholarly journals Heat Dissipation for Microprocessor Using Multiwalled Carbon Nanotubes Based Liquid

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Bui Hung Thang ◽  
Pham Van Trinh ◽  
Nguyen Van Chuc ◽  
Phan Hong Khoi ◽  
Phan Ngoc Minh

Carbon nanotubes (CNTs) are one of the most valuable materials with high thermal conductivity (2000 W/m·Kcompared with thermal conductivity of Ag 419 W/m·K). This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED). In this work, multiwalled carbon nanotubes (MWCNTs) based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU’s temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU’s temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for theμ-processor and other high power electronic devices.

2011 ◽  
Vol 130-134 ◽  
pp. 3967-3971
Author(s):  
San Shan Hung ◽  
Hsing Cheng Chang ◽  
Jhih Wei Huang

The main result of this study is to propose a liquid-cooling system for high power LED heat dissipation treatment. By using thermal dissipation mechanism and based on ANSYS CFX numerical analysis of change the parameters of cold plat. We will get the optimal heat dissipation structure. The experimental results show that the Taguchi method of thermal mechanisms in this study of the four control factors affecting the order: k value of thermal compound > fan power > liquid type > pump flow rate, and to identify the best combination of factor levels. When the heat source is 90 W, the best factor of the experimental cooling system thermal resistance is 0.563K/W. Nomenclature


Author(s):  
Sushan Nakarmi ◽  
V. U. Unnikrishnan

The increasing demand for system miniaturization and high power density energy produces excessive thermal loads on electronic devices with significant mechanical strain. Carbon Nanotubes (CNTs) based devices are found to have excellent thermal transport properties that makes them attractive for thermal management of these miniaturized nano-electronic devices under extreme environments. These conductive nanostructure (carbon nanotubes, graphene, etc.) are often embedded in polymers or other high-strain alloys (the matrix phase), and are used as bridging materials for conductivity (electrical and thermal) with strain resiliency. The effect of strain on the thermal transport properties of these nanostructures have often been overlooked and will be the focus of this work. The thermal conductivity of the nanostructure is obtained in LAMMPS using the Heat-Bath method, which is a reverse non-equilibrium molecular dynamics (RNEMD) simulation strategy. In RNEMD, constant amount of heat is added to and removed from hot and cold regions and the resultant temperature gradient is measured. The effect of strain on the thermal conductivity of the single and multiwalled nanostructures of various configurations will be discussed with specific emphasis on the phonon density of states of nanotubes at different strain states.


2013 ◽  
Vol 795 ◽  
pp. 591-596
Author(s):  
W.M. Arif ◽  
C.K. Yeoh ◽  
P.L. Teh ◽  
J.H. Lim ◽  
Hidayu Jamil Noorina

This project is focused to study on the cooling performance of liquid cooling system under different process parameter. In this research, a liquid cooling system with copper block that simulates CPU, was setup to identify cooling performance of distilled water and vegetable oil at different mass flow rates (distilled water: 8.00g/s, 10.60g/s & 13.24g/s; vegetable oil: 1.22g/s, 1.30g/s & 1.38g/s) and input power (29.12W & 47.66W). The cooling performance of each fluid was characterized by the properties of: heat transfer coefficient, thermal resistance and also, the maximum CPU temperature (T4 at 66min) for the experiments. Experimental data shows that cooling performance was improved at higher mass flow rate and both distilled water and vegetable oil is a good coolant material.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bui Hung Thang ◽  
Le Dinh Quang ◽  
Nguyen Manh Hong ◽  
Phan Hong Khoi ◽  
Phan Ngoc Minh

Overheating of the high-power light emitting diode (LED) has a dramatic effect on the chip’s lifetime. Heat dissipation for high-power LED is becoming a major challenge for researchers and technicians. Compared with the air cooling method, the liquid cooling method has many advantages and high efficiency because of higher specific heat capacity, density, and thermal conductivity. Carbon nanotubes with remarkable thermal properties have been used as additives in liquids to increase the thermal conductivity. In this work, multiwalled carbon nanotubes nanofluid (MWCNTs nanofluid) was used to enhance heat dissipation for 450 W LED floodlight. MWCNTs nanofluid was made by dispersing the OH functionalized MWCNTs in ethylene glycol/water solution. The concentration of MWCNTs in fluid was in the range between 0.1 and 1.3 gram/liter. The experimental results showed that the saturated temperature of 450 W LED chip was 55°C when using water/ethylene glycol solution in liquid cooling system. In the case of using MWCNTs nanofluid with 1.2 gram/liter of MWCNTs’ concentration, the saturated temperature of LED chip was 50.6°C. The results have confirmed the advantages of the MWCNTs for heat dissipation systems for high-power LED floodlight and other high power electronic devices.


Author(s):  
Muhammad Arif Harun ◽  
Nor Azwadi Che Sidik

Electronic devices are becoming more efficient while getting a smaller size and compact design thus increase heat generation significantly. High heat generation from high technology electronic devices are needed to be cool down or control its temperature to prevent overheating problems. Due to the high cooling performance of liquid cooling, the electronic cooling system is shifting from an air-cooling system to a liquid cooling system. In the past few decades, numerous methods proposed by researchers for the central process unit (CPU) cooling using the liquid system either active cooling or passive cooling system. Other than physical configuration such as heat sink design, different configurations of working fluids are widely been studied by most of the researchers. Different working fluids have different heat transfer performance. Furthermore, a recent study has come out more interesting finding using nanofluid which can enhance heat transfer performance of liquid cooling. Nanofluid is a working fluid that has nanoparticles disperse in the base fluid which can increase the thermal properties of the based fluid. In this paper, comprehensive literature on the type of working fluid used in the respective system and methods of liquid cooling system for CPU including its cooling performance. Furthermore, this review paper discussed the different configuration of the liquid block and also the working fluid that had been used in the CPU cooling system.


Author(s):  
Vahideh Radmard ◽  
Yaser Hadad ◽  
Srikanth Rangarajan ◽  
Cong H. Hoang ◽  
Najmeh Fallahtafti ◽  
...  

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