An Investigation of the Thermal Performance of a Novel Axial Grooved Heat Pipe

2012 ◽  
Vol 580 ◽  
pp. 223-226
Author(s):  
K.M. Yang ◽  
N.H. Wang ◽  
C.H. Jiang ◽  
L. Cheng
Keyword(s):  
Surface Tension ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Thermal Characteristics ◽  
High Heat ◽  
Input Power ◽  
Thermal Coefficient ◽  
Total Thermal Resistance ◽  
High Heat Transfer ◽  
Axial Temperature

Heat pipes are devices capable of very high heat transfer and have been widely used in many thermal management applications. An experimental investigation of thermal characteristics of heat pipe with axial ‘‘Ω”-shaped grooves was presented in this paper. The effects of angle of inclination and input power on thermal performance of heat pipe were investigated, the surface tension and gravity both impacted the fluid flow in heat pipe, and which one was dominating was analyzed. Experimental results indicate that the working temperature of heat pipe, the axial temperature differences and the maximum axial temperature differences increase when increasing the input heat flux. The total thermal resistances become smaller with the input power increasing, but become bigger with the angle of inclination increasing. And the trend of the thermal coefficient of heat pipe reverses that of the total thermal resistance. The influence of gravity on thermal performance is weaker than that of the surface tension.

Study on Heat Transfer Characteristics of Heat Pipe with Axial “Ω”-Shaped Microgrooves

2012 ◽  
Vol 580 ◽  
pp. 297-300
Author(s):  
K.M. Yang ◽  
N.H. Wang ◽  
C.H. Jiang ◽  
L. Cheng
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Thermal Characteristics ◽  
High Heat ◽  
Input Power ◽  
Operational Characteristic ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Working Temperature ◽  
High Heat Transfer

Heat pipes are devices capable of very high heat transfer and have been widely used in many thermal management applications. Heat pipe with axial ‘‘Ω”-shaped grooves combines a high capillary pumping pressure with a low axial pressure drop in the liquid. An experimental investigation of thermal characteristics of heat pipe with axial ‘‘Ω”-shaped grooves was presented in this paper. The experimental results showed that the work temperatures affect the equivalent heat transfer coefficients obviously, and 20 °C is chosen to be the most appropriate working temperature for heat pipe in present study. The working temperature affects the operational characteristic of heat pipe significantly. When the working temperature is 20 °C, the most efficient working input power is from 80 to 140W. The tilt angles affect the equivalent heat transfer coefficients not so obviously.

Experimental Research and Simulation in a Thermosyphon

2012 ◽  
Vol 580 ◽  
pp. 441-444
Author(s):  
K.M. Yang ◽  
N.H. Wang ◽  
C.H. Jiang ◽  
L. Cheng
Keyword(s):  
Heat Pipe ◽  
Cfd Simulation ◽  
Thermal Characteristics ◽  
Heat Pipes ◽  
High Heat ◽  
Evaporation And Condensation ◽  
Maximum Value ◽  
High Heat Transfer ◽  
Adiabatic Section ◽  
Very High

Heat pipes are devices capable of very high heat transfer and have been widely used in many thermal management applications. An experimental investigation and CFD simulation of thermal characteristics of heat pipe was presented in this paper. It can be found that UDF in FLUENT can simulate the evaporation and condensation in heat pipe. The pressure difference between evaporation section and condenser ensure the vapor can flow successfully from the evaporation section to condenser. In steady state, the fluctuation of axial velocity is very small in the most area in heat pipe. In general, the magnitudes of velocity vary from 0 to maximum from the end of both evaporation section and condenser, and the maximum value was maintained in the adiabatic section.

Study on a Pulsating Heat Pipe With Self-Rewetting Fluid

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Koji Fumoto ◽  
Masahiro Kawaji ◽  
Tsuyoshi Kawanami
Keyword(s):  
Surface Tension ◽  
Heat Pipe ◽  
Heat Transport ◽  
Heated Surface ◽  
Input Power ◽  
Water Mixture ◽  
Pulsating Heat Pipe ◽  
Maximum Heat ◽  
Dry Spot ◽  
Heat Transport Capability

This paper discusses a pulsating heat pipe (PHP) using a self-rewetting fluid. Unlike other common liquids, self-rewetting fluids have the property that the surface tension increases with temperature. The increasing surface tension at a higher temperature can cause the liquid to be drawn toward a heated surface if a dry spot appears and thus to improve boiling heat transfer. In experiments, 1-butanol and 1-pentanol were added to water at a concentration of less than 1 wt % to make self-rewetting fluid. A pulsating heat pipe made from an extruded multiport tube was partially filled with the self-rewetting fluid water mixture and tested for its heat transport capability at different input power levels. The experiments showed that the maximum heat transport capability was enhanced by a factor of 4 when the maximum heater temperature was limited to 110°C. Thus, the use of a self-rewetting fluid in a PHP was shown to be highly effective in improving the heat transport capability of pulsating heat pipes.

Experimental study on a R134a loop heat pipe with high heat transfer capacity

2021 ◽  
Author(s):  
Changwu Xiong ◽  
Lizhan Bai ◽  
Hechao Li ◽  
Yuandong Guo ◽  
Yating Yu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Pipe ◽  
High Heat ◽  
Loop Heat Pipe ◽  
High Heat Transfer ◽  
Heat Transfer Capacity

scholarly journals Experimental Study on Thermal Performance of a Bent Copper-Water Heat Pipe

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shuangshuang Miao ◽  
Jiajia Sui ◽  
Yulong Zhang ◽  
Feng Yao ◽  
Xiangdong Liu
Keyword(s):  
Heat Flux ◽  
Heat Pipe ◽  
Critical Heat Flux ◽  
Working Conditions ◽  
Thermal Performance ◽  
Heat Input ◽  
High Heat ◽  
High Heat Flux ◽  
Electronic Components ◽  
Copper Water

Vapor-liquid phase change is regarded as an efficient cooling method for high-heat-flux electronic components. The copper-water bent heat pipes are particularly suited to the circumstances of confined space or misplaced heat and cold sources for high-heat-flux electronic components. In this paper, the steady and transient thermal performance of a bent copper-water heat pipe is studied based on a performance test system. The effects of cooling temperature, working conditions on the critical heat flux, and equivalent thermal conductivity have been examined and analyzed. Moreover, the influences of heat input and working conditions on the thermal response of a bent heat pipe have also been discussed. The results indicate that the critical heat flux is enhanced due to the increases in cooling temperature and the lengths of the evaporator and condenser. In addition, the critical heat flux is improved by extending the cooling length only when the operating temperature is higher than 50°C. The improvement on the equivalent thermal by increasing the heating length is more evident than that by increasing cooling length. It is also demonstrated by the experiment that the bent copper-water heat pipe can respond quickly to the variation of heat input and possesses superior transient heat transfer performance.

Heat Pipe Solar Receivers for Concentrating Solar Power (CSP) Plants

2013 ◽  
Author(s):  
Yiding Cao
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Power ◽  
High Heat ◽  
Solar Flux ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Efficient Operation ◽  
High Heat Transfer ◽  
Solar Receiver

This paper introduces separate-type heat pipe (STHP) based solar receiver systems that enable more efficient operation of concentrated solar power plants without relying on a heat transfer fluid. The solar receiver system may consist of a number of STHP modules that receive concentrated solar flux from a solar collector system, spread the high concentrated solar flux to a low heat flux level, and effectively transfer the received heat to the working fluid of a heat engine to enable a higher working temperature and higher plant efficiency. In general, the introduced STHP solar receiver has characteristics of high heat transfer capacity, high heat transfer coefficient in the evaporator to handle a high concentrated solar flux, non-condensable gas release mechanism, and lower costs. The STHP receiver in a solar plant may also integrate the hot/cold tank based thermal energy storage system without using a heat transfer fluid.

Investigation on the Use of Nanofluids to Enhance Heat Pipe Performance

Solar Energy ◽  
2005 ◽  
Author(s):  
Tomer Israeli ◽  
T. Agami Reddy ◽  
Young I. Cho
Keyword(s):  
Thermal Conductivity ◽  
Surface Tension ◽  
Thermal Resistance ◽  
Copper Oxide ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Thermal Network ◽  
Overall Resistance

This paper reports on preliminary experimental results on using nanofluids to enhance the thermal performance of heat pipes. Our experience with preparing copper oxide (CuO) nanofluids is described. Contrary to earlier studies which report infinite shelf life, we found that nanofluid stability lasted for about three weeks only; an issue which merits further study. We have also conducted various experiments to measure the variation of thermal conductivity and surface tension with CuO nanofluid concentration. Actual experiments on nanofluid heat pipes were also performed which indicated an average 12.5% decrease in the overall thermal resistance of the heat pipe using nanofluid of 3% vol concentration. This observed improvement is fairly consistent with our predictions using a simple analytical thermal network model for heat pipe overall resistance and the measured nanofluid conductivity. The results, though encouraging, need more careful and elaborate experimental studies before the evidence can be deemed conclusive.

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