Proceedings of the
International Conference on Mechanical Engineering 2009
(ICME2009) 26- 28 December 2009, Dhaka, Bangladesh

ICME09-TH-18

EXPERIMENTAL INVESTIGATION OF A HEAT PIPE FOR
DIFFERENT WORKING FLUIDS AND FILL RATIOS

A. Kumar Mozumder, A. Fahad Akon and M. S. Hasib Chowdhury
Department of Mechanical Engineering, Bangladesh University of Engineering & Technology,
Dhaka, Bangladesh.

ABSTRACT

During last thirty years, component density on integrated circuits has grown from about six thousand on the Intel 8080 microprocessor to over five million transistors on a similar-sized Intel microprocessor. Power and component densities on these integrated circuits have required the development of innovative cooling methods. Miniature heat pipes appear promising for use in microelectronics cooling. The heat pipe though has a wide application; the information available towards the development of an efficient heat pipe is seldom seen in the open literature. In the present study, investigations are carried out for optimizing the fluid inventory in a typical heat pipe. A “flooded” (with exceedingly large amount of working fluid) heat pipe has slow response and has limited lower range of operation in terms of operating temperature. On the other hand, “starving” (with too little amount of working fluid) heat pipe although Exhibits fast response to heat loads, shows severe limit at high temperature conditions. In the present study, an attempt is made to design, fabricate and test a miniature heat pipe with 5 mm diameter and 150 mm length with a thermal capacity of 10 W. Experiments were conducted with and without working fluid for different thermal loads to assess the performance of heat pipe. The working fluids chosen for the study were same as those commonly used namely, water, methanol and acetone. The temperature distribution across the heat pipe was measured and recorded using thermocouples. The performance of the heat pipe was quantified in terms of thermal resistance and overall heat transfer coefficient. The amount of liquid filled was varied and the variation of the performance parameters for varying liquid inventory is observed. Finally, optimum liquid fill ratio is identified in terms of lower temperature difference and thermal resistance and higher heat transfer coefficient. The data reported in this study will serve as a good database for the researchers in this field. Overall heat transfer coefficient of the Miniature heat pipe is found to be the maximum for the Acetone as working fluid.

Keywords: Miniature Heat Pipe, Working Fluid Inventory

Click here to download here full report.