A heat pipe is a two-phase heat transfer device with an extremely high effective thermal conductivity. It can be cylindrical or planar, and the inner surface is lined with a capillary wicking material. The heat pipe is evacuated and back-filled with a small quantity of a working fluid such as water, acetone or methanol. Heat is absorbed in the evaporator region by vaporizing the working fluid. The vapor transports heat to the condenser region where the vapor condenses, releasing heat to the cooling medium such as air. The condensed working fluid is returned to the evaporator by gravity or by capillary action if working against gravity.
Heat pipes have a lower total thermal resistance than solid conductors, enabling them to transfer heat more efficiently and evenly. They are totally passive heat transfer systems, having no moving parts to wear out and requiring no energy to operate. Heat pipes offer the design engineer low-cost packaging flexibility because they can be manufactured in a variety of shapes and sizes. Their light weight and compact size also make them the ideal choice for space-constrained applications. Heat pipes can be manufactured to survive freeze-thaw conditions.
Overview
A heat pipe is a two-phase heat transfer device with an extremely high effective thermal conductivity. It can be cylindrical or planar, and the inner surface is lined with a capillary wicking material. The heat pipe is evacuated and back-filled with a small quantity of a working fluid such as water, acetone or methanol. Heat is absorbed in the evaporator region by vaporizing the working fluid. The vapor transports heat to the condenser region where the vapor condenses, releasing heat to the cooling medium such as air. The condensed working fluid is returned to the evaporator by gravity or by capillary action if working against gravity.
