Experimental Investigation Thermal Performance of Loop Heat Pipe Operating with Different Working Fluids


  • Phuoc Hien Huynh Saga University, Saga, Japan
  • Kyaw Zin Htoo Saga University, Saga, Japan
  • Keishi Kariya Saga University, Saga, Japan
  • Akio Miyara Saga University, Saga, Japan




Electronics cooling, Loop heat pipe, Working fluids, Gravity assisted condition, Water, Ethanol, Boiling heat transfer, Condensation heat transfer.


 Nowadays, due to the tremendous development of data centers (DCs), studying the effective cooling methods that can face to the challenges such as the high power or heat flux dissipation and the efficient electricity consumption in DCs has never been unnecessary. Loop heat pipe (LHP), a two-phase heat transfer device, is being considered as one of the potential solutions for the above problems. This paper introduces the experimental study on the thermal performances of LHP functioning under gravity assisted condition with different working fluids that are water and ethanol (C2H5OH). This LHP has the flat-rectangular evaporator with the stainless-steel (SS) sintering wick installed inside. The results demonstrate that under the same condenser cooling condition, water LHP performed better than ethanol LHP. In the case of water LHP, when heating power was increased from 33 to 535 W, the temperature at the top surface of the heating block raised from 38oC to 110oC. With the ethanol LHP, this temperature reached 133oC at the heating power of 395 W. If temperature limitation of microprocessors functioning inside the DCs is recognized at 85oC, the cooling capabilities of LHP are 220 W and 350 W corresponding to the working fluid are ethanol and water respectively. In addition, the discussions about the difference in boiling heating transfer characteristics as well as condenser performances between water LHP and ethanol LHP are also presented in this study.

Author Biographies

Phuoc Hien Huynh, Saga University, Saga, Japan

Graduate school of Science and Engineering

Kyaw Zin Htoo, Saga University, Saga, Japan

Graduate school of Science and Engineering

Keishi Kariya, Saga University, Saga, Japan

Department of Mechanical Engineering

Akio Miyara, Saga University, Saga, Japan

Department of Mechanical Engineering


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How to Cite

Phuoc Hien Huynh, Kyaw Zin Htoo, Keishi Kariya, Akio Miyara. Experimental Investigation Thermal Performance of Loop Heat Pipe Operating with Different Working Fluids. J. Adv. Therm. Sci. Res. [Internet]. 2019Oct.6 [cited 2021Sep.26];6(1):19-30. Available from: https://www.avantipublishers.com/jms/index.php/jatsr/article/view/877