An Investigation of Temperature Characteristics of Pulsating Heat Pipe

Pulsating heat pipe (PHP) is an interesting heat transfer device. This paper focuses on PHP heat transfer characteristics versus its operating temperature. In experiments of copper and stainless steel PHPs, results indicate that, at a same input power, both temperature differences (from the evaporator to condenser) and evaporator temperature fluctuations are relevant to operating temperature. The minimal temperature difference and fluctuation appear at an operating temperature ranging from 120 to 160°C. Experimental analysis of the evaporator temperature fluctuations show that single phase cooling in PHP causes a large temperature difference (between the evaporator and condenser) and fluctuation. Phase change proportion increases at the optimal operation condition. Static mechanical balance combining with dynamic elastic oscillation system is used to interpret PHP temperature variations versus operating temperature.

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Operating Characteristic Investigations in Pulsating Heat Pipe

Journal of Heat Transfer ◽

10.1115/1.2349509 ◽

2006 ◽

Vol 128 (12) ◽

pp. 1329-1334 ◽

Cited By ~ 34

Author(s):

Qingjun Cai ◽

Chung-lung Chen ◽

Julie F. Asfia

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Temperature Difference ◽

Temperature Fluctuation ◽

Operating Temperature ◽

Temperature Fluctuations ◽

Pulsating Heat Pipe ◽

Oscillation System ◽

Evaporator Temperature ◽

Total Temperature

Pulsating heat pipe (PHP) is an interesting heat transfer device. In this paper we focus on PHP heat transfer characteristics versus its operating temperature. In experiments of copper and stainless steel PHPs, results indicate that, at a same input power, both the total temperature differences (from the evaporator to condenser) and the evaporator temperature fluctuations are relevant to operating temperature. The minimal total temperature difference and temperature fluctuation appear at an operating temperature ranging from 120°Cto160°C. Experimental analysis of the evaporator temperature fluctuations show that single phase cooling in PHP causes a large total temperature difference and temperature fluctuation. Phase change proportion increases at the optimal operating temperature. Static mechanical balance combining with dynamic elastic oscillation system is used to interpret PHP temperature variations versus the operating temperature.

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Experimental Investigation of Heat Transfer of Refrigerant Fluid Pulsating Heat Pipe

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.865.137 ◽

2017 ◽

Vol 865 ◽

pp. 137-142

Author(s):

Somchai Maneewan ◽

Chantana Punlek ◽

Hoy Yen Chan ◽

Atthakorn Thongtha

Keyword(s):

Heat Transfer ◽

Thermal Resistance ◽

Heat Pipe ◽

Temperature Difference ◽

Heat Input ◽

Filling Ratio ◽

Working Fluid ◽

Pulsating Heat Pipe ◽

Filling Volume ◽

Volume Filling

Heat transfer performances of a pulsating heat pipe (PHP) having internal and external diameter with 4.5 mm and 6 mm with various contents of refrigerant are experimentally investigated. The working fluid as R404A refrigerant was filled in the volume ratios from 0% to 80% and the heat input was controlled in the range from 10 W to 80 W. Obtained results exhibited the ability of R404A refrigerant can enhance the thermal performance in steady state condition. The average temperature difference of the evaporating section and condensing section in the 80% filling volume ratio decreased from 9.5 °C to 2.5 °C when the heating power increase from 10 W to 80 W. The thermal resistance of evaporator and condenser decreased with an increase of the heat input as well. For other filling volume ratios, the trend of temperature difference and thermal resistance was similar to that of the 80% volume filling ratio. Considering the same heat input, the highest heat transfer performance was found at the 80% volume filling ratio. Refrigerant with a relatively low dynamic consistency can lead to relatively high velocity in the PHP that can reduce the temperature difference between the evaporating section and condensing section.

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Heat Transfer Enhancement of Planar Pulsating Heat Pipe Device

Heat Transfer, Volume 2 ◽

10.1115/imece2006-13737 ◽

2006 ◽

Cited By ~ 3

Author(s):

Qingjun Cai ◽

Chung-Lung Chen ◽

Julie F. Asfia

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Printed Circuit Boards ◽

Longitudinal Direction ◽

High Heat ◽

Electronic Cooling ◽

Circuit Boards ◽

Pulsating Heat Pipe ◽

Evaporator Temperature ◽

Key Factor

Heat pipes are widely used heat transfer devices in the electronic cooling area. In this paper, a novel pulsating heat pipe (PHP) design, which combines features of PHP and capillary microstructures, is presented to enhance heat transfer of electronic printed circuit boards (PCB). Test prototype fabrication is initiated by making dual-radius serpentine channels on a 4.0mm thick aluminum plate, followed by compressing 4.67mm diameter copper tube into the grooves, and completed by generating a millimeter sized liquid channel with micro-grooves in the PHP along the longitudinal direction. Because of this design, the planar PHP is able to circulate operating liquid by both capillary pump and oscillation motions, which eliminate the dry state in the evaporator section and supply sufficient coolant at high heat loads. Demonstrations of heat transfer performance indicate that the planar PHP has high effective thermal conductivity and low evaporator temperature fluctuations, and oscillation continuity is the key factor to reduce the temperature difference between the evaporator and condenser.

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The Particular Phenomenon of Pulsating Heat Pipe during its Operation Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.354-355.1301 ◽

2011 ◽

Vol 354-355 ◽

pp. 1301-1304 ◽

Cited By ~ 1

Author(s):

Xun Wang ◽

Xin Xin Mao ◽

Lei Wang ◽

Tong Han ◽

Cheng Si Yang

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Operating Temperature ◽

Operating Conditions ◽

Pulsating Heat Pipe ◽

Transfer Property ◽

Experimental Data Processing ◽

Fundamental Investigation ◽

Operation Process ◽

Heat Transfer Property

Combined with the existing research results, the heat transfer property of Pulsating Heat Pipe (PHP) was analyzed on the basis of experimental data processing in multi-operating conditions. PHP could self-repair when heat transfer was deteriorated, and the operating temperature continued to rise with the increased heating power during the operation. This study would contribute to the safe and effective operating; moreover, it could lay foundations for the fundamental investigation of PHP.

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Analysis of Entropy Generation of a Magneto-Hydrodynamic Flow Through the Operation of an Unlooped Pulsating Heat Pipe

Journal of Heat Transfer ◽

10.1115/1.4039215 ◽

2018 ◽

Vol 140 (8) ◽

Author(s):

Mobadersani Farrokh ◽

Toolabi Goodarz ◽

Jafarmadar Samad ◽

Nasiri Javid ◽

Habibzadeh Amin

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Heat Pipe ◽

Entropy Generation ◽

Uniform Magnetic Field ◽

Pipe Diameter ◽

Bejan Number ◽

Pulsating Heat Pipe ◽

Viscous Effects ◽

Evaporator Temperature

The aim of the study is the analysis of a uniform magnetic field effect on fluid flow, heat transfer, and entropy generation through the operation of a pulsating heat pipe (PHP). An open loop PHP with three neighboring vapor plugs and two liquid slugs has been considered. The governing equations such as momentum, energy, and mass equations are solved using an explicit method except for the energy equation of liquid slugs. For each case study, Bejan number has been derived to find the heat transfer share in entropy generation. According to the results, the performance of the oscillating heat pipe decreases by applying uniform magnetic field. Moreover, the obtained results illustrate the effects of the applied magnetic field position on the heat transfer and the entropy generation. The latent and sensible heat transfer into the PHP enhance as a result of increase in the pipe diameter, so that the liquid slugs oscillate with high amplitudes. In addition, the entropy generation value increases with an augmentation in the value of the pipe diameter. The evaluated Bejan numbers indicate that the viscous effects in entropy generation decrease as the pipe diameter increases. Furthermore, the results depict that the heat transfer performance of PHP improves by increasing temperature difference between evaporator and condenser sections. With an increase in the value of the evaporator temperature, the Bejan number will increase, as a result, this phenomenon reveals the inconsiderable role of viscous impacts in high evaporator temperatures. In order to validate the calculations, the calculated results have been compared with the previous studies which show good agreement.

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Experimental Performance of a Nanofluid Pulsating Heat Pipe

2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems ◽

10.1115/micronano2008-70316 ◽

2008 ◽

Cited By ~ 2

Author(s):

Wei Qu ◽

Chong Qu ◽

Jianchao Feng

Keyword(s):

Heat Transfer ◽

Thermal Resistance ◽

Heat Pipe ◽

Operating Temperature ◽

Nano Particles ◽

Working Fluid ◽

Pulsating Heat Pipe ◽

Operation Temperature ◽

Heating Section ◽

Inclination Angles

The startup and operating performances of a nanofluid pulsating heat pipe are experimented. When the working fluid is selected as nanofluid instead of the base working fluid, the pulsating heat pipe can work at lower heating loads and start up more quickly and the thermal resistance between the heating section and the cooling section significantly decreases. For the nanofluid and base working fluid, the operating temperature increases with the heating load, the thermal resistance of pulsating heat pipe decreases with the operating temperature. The inclination angles of pulsating heat pipe as 30°, 60°, or 90°, have little effects on heat transfer performance. Under a vertical bottom heating mode of 100 watts and at the operation temperature of 110 °C, the thermal resistance of TiO2/H2O nanofluid pulsating heat pipe can be 0.11 °C/W, while it is 0.23 °C/W for the base working fluid. The mechanisms that the nanofluid pulsating heat pipe has better performance are tentatively explained as, the nano particles can form many micro nuclear centers for the boiling, and can lead to several heat transfer enhancement.

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Water pulsating heat pipe

EPJ Web of Conferences ◽

10.1051/epjconf/201919600043 ◽

2019 ◽

Vol 196 ◽

pp. 00043

Author(s):

Viacheslav Cheverda ◽

Fedor Ronshin

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Heat Pipe ◽

Temperature Difference ◽

Transfer Problem ◽

Heat Transfer Problem ◽

Experimental Setup ◽

Pulsating Heat Pipe

The new experimental setup with copper-glass pulsating heat pipe has been constructed for investigation of the heat transfer problem. Pulsations of liquid slugs inside the heat pipe has been observed. It is demonstrated that with increasing of temperature difference between evaporator and condenser heat flux which can be removed is also increases.

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