Abstract—Increasing performance of electronic components is resulting in higher heat flux dissipation. Two-phase Passive devices are proven solutions for modern microelectronics thermal management. In this context, Pulsating Heat Pipe (PHP) cooling is the new and emerging technique in the field of thermal management of electronics. In the present work, transient and steady state experiments are conducted on a two turn closed loop PHP. Copper is used as the capillary tube material in the evaporator and condenser sections with inner diameter of 2 mm and outer diameter of 3 mm. The total length of the closed loop pulsating heat pipe is 1080 mm. The evaporator and condenser sections are 360 mm and 280 mm respectively. The experiments are conducted on vertical orientations for different heat loads varying from 10 W to 100 W in steps of 10 W. The PHP is tested on Ethanol, Methanol, Acetone and Water as working fluids for different fill ratios from 0% to 100% in steps of 20%. The performance parameters such as temperature difference between evaporator and condenser, thermal resistance and the overall heat transfer coefficient are evaluated. The experimental results demonstrate the heat transfer characteristics, lower thermal resistance and higher heat transfer coefficient of PHP are found to be better at a fill ratio of 60% for various heat input.

Index Terms—Pulsating heat pipe, Fill ratio, Orientation, Working fluids

Cite: Dharmapal A Baitule and Pramod R Pachghare, "Experimental Analysis of Closed Loop Pulsating Heat Pipe with Variable Filling Ratio," International Journal of Mechanical Engineering and Robotics Research, Vol.2 No.3, pp. 113-121, July 2013.