Influence of Drainage and Tilt on Heat Transfer Performance of Array Pulsating Cold End Heat Pipe

Author(s):  
Guowei Xiahou ◽  
Hao Liu ◽  
Shun Zhang ◽  
Yecong He

Abstract A new type of array pulsating cold section heat pipe was proposed, which consists of a T-shaped hot section and an array pulsating cold section. The special structure is available to drain the hot section of the heat pipe, and the installation method of the cold section has an important influence on heat transfer. For this reason, a detailed experimental study of heat transfer performance was carried out in this paper. It was found in the study that a capillary lifting force exists at the outlet of the cold section channel, which prevents the condensate from returning to the hot section, therefore, the hot section has to be drained; the drainage methods are divided into hot-section liquid drainage and hot-section capillary drainage, the latter is significantly better than the former; appropriate increase of the filling rate can improve the drainage effect of liquid drainage. The new heat pipe can adopt two methods, i.e., inclined cold section and vertical cold section. The reflux and heat transfer performance of the inclined cold section outperforms that of the vertical cold section, but the difference between the two methods gradually decreases with the increase of power. Under the same working conditions, the average temperature of the heat source of the new stainless steel heat pipe with the capillary drainage vertical cold section is lower than that of the aluminum fin radiator by 5.79%-10.78%, and the decreasing amplitude increases with the increase of the heating power.

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 751-760
Author(s):  
Lei Lei

AbstractTraditional testing algorithm based on pattern matching is impossible to effectively analyze the heat transfer performance of heat pipes filled with different concentrations of nanofluids, so the testing algorithm for heat transfer performance of a nanofluidic heat pipe based on neural network is proposed. Nanofluids are obtained by weighing, preparing, stirring, standing and shaking using dichotomy. Based on this, the heat transfer performance analysis model of the nanofluidic heat pipe based on artificial neural network is constructed, which is applied to the analysis of heat transfer performance of nanofluidic heat pipes to achieve accurate analysis. The experimental results show that the proposed algorithm can effectively analyze the heat transfer performance of heat pipes under different concentrations of nanofluids, and the heat transfer performance of heat pipes is best when the volume fraction of nanofluids is 0.15%.


2012 ◽  
Vol 197 ◽  
pp. 216-220
Author(s):  
Zhong Chao Zhao ◽  
Rui Ye ◽  
Gen Ming Zhou

To solve the cooling problem in modern electronic device, a kind of heat pipe radiator was designed and manufactured in this paper. The heat transfer performance of heat pipe radiator and its relationship with air velocity were investigated by experimental method. The experimental results show that the heat pipe radiator can meet the temperature requirement of electronic device with the power range from 40W to 160W. To keep the operational temperature of electronic device with power of 160W under 75°C,the air velocity should be keep at 1.7m/s. The heat dissipation performance of heat pipe radiator was enhanced with the air velocity increased from 0.2m/s to 1.7m/s.for the electronic equipment with power of 160W.


2014 ◽  
Vol 595 ◽  
pp. 24-29 ◽  
Author(s):  
Shen Chun Wu ◽  
Kuei Chi Lo ◽  
Jia Ruei Chen ◽  
Chen Yu Chung ◽  
Weie Jhih Lin ◽  
...  

This paper specifically addresses the effect of the sintering temperature curve in manufacturing nickel powder capillary structure (wick) for a loop heat pipe (LHP) with flat evaporator. The sintering temperature curve is composed of three regions: a region of increasing temperature, a region of constant temperature, and a region of decreasing temperature. The most important region is the increasing temperature region, as the rate of temperature increase directly affects the performance of the wick.When the slope of the region of increasing temperature is 0.8 (equivalent to 8 OC/min), the structure of the manufactured wick is complete, with the best heat transfer performance result. Experimental resultsshowed that the optimal heat transfer performance is 160W, the minimal total thermal resistance is approximately 0.43OC/W, and the heat flux is 17W/cm2; the optimal wick manufactured has an effective pore radius of 5.2 μm, a permeability of 5.9×10-13m2, and a porosity of 64%.


Author(s):  
Sandesh S. Chougule ◽  
S. K. Sahu

In the present study, the forced convective heat transfer performance of two different nanofluids, namely, Al2O3-water and CNT-water has been studied experimentally in an automobile radiator. Four different concentrations of nanofluid in the range of 0.15–1 vol. % were prepared by the additions nanoparticles into the water as base fluid. The coolant flow rate is varied in the range of 2 l/min–5 l/min. Nanocoolants exhibit enormous change in the heat transfer compared with the pure water. The heat transfer performance of CNT-water nanofluid was found to be better than Al2O3-water nanocoolant. Furthermore, the Nusselt number is found to increase with the increase in the nanoparticle concentration and nanofluid velocity.


2019 ◽  
Vol 148 ◽  
pp. 878-885 ◽  
Author(s):  
Nampon Sangpab ◽  
Nobuhiro Kimura ◽  
Pradit Terdtoon ◽  
Phrut Sakulchangsatjatai ◽  
Niti Kammuang-lue ◽  
...  

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