Performance Evaluation of Bent Heat Pipes

摘要

Heat pipes are used in electronics cooling applications to transfer heat generated by devices to locations where it can efficiently be dissipated. Heat pipes have been studied since the early 1950s and are commercially available in a variety of forms. They are usually bent and flattened in order to fit within the specific geometrical restrictions of the intended application. Straight heat pipes have been studied and successfully demonstrated in past studies. The objective of the present work is to investigate the performance of heat pipes at various bend angles by means of investigating the effect of temperature drop between bend angles, the temperature difference across source and sink blocks and change in thermal resistance across the heat pipes. Copper heat pipes with meshed screen wick type having de-ionized water as the fluid with bent pipes varying from zero degree (straight pipe) to 180° (U - shaped pipe) in-steps of 45° were studied at various input power levels. Results show that the temperature drop is maximum for U-shaped heat pipe at 180° bend. Furthermore, it was observed that the heat pipe with temperature differential was higher for all bends at higher input power. Lastly, the thermal resistance calculated analytically was validated via experimental measurements.