The heat pipe and thermosyphon are passive heat transfer devices with phase change, which can be applied for thermal management of thermoelectric cooling, such as the TEC hot side. The heat pipes basically consist of a metal tube sealed with capillary structure internally that is embedded with a working fluid. This capillary structure can be made of screen meshes, grooves, or sintered media. The thermosyphon is a heat pipe assisted by gravity, because it has no capillary structure. Then, in this chapter, manufacturing of low cost and easy-to-manufacture heat pipes and thermosyphon is described in detail, and an experimental evaluation of their thermal performance is accomplished. The considered devices were a rod, a thermosyphon, a mesh heat pipe, a grooved heat pipe, and a sintered heat pipe. According to the behavior of the global thermal resistance and the effective thermal conductivity, the passive devices operated satisfactorily with the exception of the rod and the thermosyphon in the horizontal position. The heat pipes were the best among the tested devices and the best position was vertical.
Part of the book: Bringing Thermoelectricity into Reality