The effect of orientation on U-shaped grooved and sintered wick heat pipes

The thermal management system for a compact sealed computer is studied here. The system consists of two heat spreaders that are connected by two U-shaped heat pipes. The heat pipes are used to transport the heat directly from the chipset to the finned case wall where it is dissipated to the ambient by natural convection. In this study, the effect of orientation on the performance of the U-shaped heat pipe was determined. Temperature difference and thermal resistance were measured for a range of heat load values ranging from 0 W to 45 W per heat pipe. Heat pipes with an eccentric sintered wick structure and with an axial groove wick structure were tested. The orientation was found to have a significant effect on the axial groove wick heat pipe performance with a much smaller effect on the sintered wick heat pipe performance. The experimental results were in good agreement with that predicted from the basic governing equations of heat pipes.