Abstract:
Overheating of integrated circuit (Ie), microchip etc. is a potential threat to
these electronic components. It is very important to facilitate optimum cooling of
electronic components in a smaller electronic device because integrated circuit lifetime
depends on it. An increasing market demand on powerful gadgets in smaller and
smaller cabinets creates a trade off situation: either to enlarge the package to accept
additional cooling or to sacrifice IC lifetime. This is a great challenge in thermal design
management. Among other cooling techniques heat pipe emerges as the most
appropriate technology and cost effective thermal design solution due to its excellent
heat transfer capability, high efficiency and its structural simplicity. Due to the space
constraint in most of personal computers and telecommunication devices, the size of
heat pipes has to be carefully decided. Thus application of micro heat pipe (MHP) has
been extended gradually. So investigation on MHP is indispensable for further
development and improvement of its performance.
An experimental study has been performed to investigate the heat transfer
characteristics of micro heat pipe (MHP) of circular geometry having inner diameter of
1.8 mm and length of 150 mm. The experimental parameters are inclination angle,
coolant flow rate, working fluid and heat input. Taking acetone, ethanol and methanol
as working fluid, heat transfer characteristics are determined experimentally for
different inclination angle and different coolant flow rate at different heat input.
An analysis of the experimental data gives following findings: Coolant flow rate
has an insignificant effect on the performance of MHP. Performance of MHP depends
upon angle of inclination. Better performance is found for an inclination angle of 700.
Heat input has significant effect on the performance of MHP. It is found that overall
heat transfer coefficient is higher for higher heat input. Finally, it is observed that for
the same heat input and inclination angle MHP with acetone as working fluid performs
better.
An empirical correlation has also been developed which correlates all the
experimental data within o!o 7% error.
