Journal of South China University of Technology(Natural Science) >

2022 , Vol. 50 >Issue 7: 126 - 135

DOI: https://doi.org/10.12141/j.issn.1000-565X.210548

Power & Electrical Engineering

Analysis of Operation Characteristics of Pulsating Heat Pipe Under the Condition of Non-uniform Heat Flux

  • Dong ZHANG ,
  • Hongyi HOU ,
  • Qingliang LI ,
  • Jianghao WU ,
  • Baorui XU ,
  • Zhoujian AN ,
  • Linjun WANG
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  • 1.School of Energy and Power Engineering，Lanzhou University of Technology，Lanzhou 730050，Gansu，China
    2.Gansu Key Laboratory of Biomass and Solar Complementary Energy Supply System，Lanzhou 730050，Gansu，China
    3.School of Mechanical and Electronical Engineering，Lanzhou University of Technology，Lanzhou 730050，Gansu，China
    4.Tiandi Shanghai Excavating Equipment Technology Co. ，Ltd. ，Shanghai 200030，China
张东（1985-），男，博士，副教授，主要从事可再生能源利用及热管高效传热研究。

Received date: 2021-08-25

  Online published: 2021-11-10

Supported by

the National Natural Science Foundation of China(51806093);the Natural Science Foundation of Gansu Province(20JR10RA193)

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Abstract

To further explore the influence of different operating parameters on the heat transfer characteristics of pulsating heat pipe under the condition of non-uniform heat flux and broaden the application scenarios of pulsating heat pipe, this study constructed an experimental platform of pulsating heat pipe with non-uniform heat flux. The platform consists of pulsating heat pipe module, heating module, cooling water circulation module, data measurement and acquisition module, and filling and vacuum working medium module. In order to ensure the reliability of the experimental results, the stability test was carried out. Under the conditions of 50% and 70% liquid filling rate, the performance of heat transfer, evaporation temperature and internal pressure fluctuation characteristics were studied by using ethanol and HFE-7100 as the working mediums and varying the heating power from 40W to 140 W and the dimensionless heat difference from 0 to 0.56. The results show that the HFE-7100 has lower operating thermal resistance at low heating power under uniform heat flux. With the increase of heating power, the thermal resistances of the two kinds of working fluid gradually get close to each other at 50% and 70% filling rate. Alone with the raise of dimensionless heat difference, the operating thermal resistance of the pulsating heat pipe under non-uniform heat flux is lower or close to the uniform heat flux. And the evaporation temperature of the pulsating heat pipe with high liquid filling rate has better stability during start-up and operation. There exists a critical value of dimensionless heat difference (0.33) for pulsating heat pipe under 70% liquid filling rate of non-uniform heat flux. When the value exceeds 0.33, the vapor-liquid working fluid at different heat flux sides can break the equilibrium rapidly, thus improving the circulating flow state and reducing the operating thermal resistance. When the ethanol working medium is heated with a uniform heat flux density, there are a large number of long liquid plugs in the tube under the high liquid filling rate, which is prone to the phenomenon of working medium flow stagnation. When the non-uniform heat flux density is heated, due to the high heat flux density side in the heating section of the device, the moving direction of the working fluid in the pipe of different elbows is consistent, reducing the stagnation and reversal in the internal fluid flow process, so as to improve the heat transfer performance of the pulsating heat pipe device within a certain dimensionless range.

Key words： pulsating heat pipe; heat transfer; dimensionless thermal difference; liquid filling rate; gas-liquid flow; gasification

Cite this article

Dong ZHANG , Hongyi HOU , Qingliang LI , Jianghao WU , Baorui XU , Zhoujian AN , Linjun WANG . Analysis of Operation Characteristics of Pulsating Heat Pipe Under the Condition of Non-uniform Heat Flux[J]. Journal of South China University of Technology(Natural Science), 2022 , 50(7) : 126 -135 . DOI: 10.12141/j.issn.1000-565X.210548

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