Heat Pipe Selection, Bending and Application Strategies
. by Dr. Rahul Mulinti, Ph.D.,
Heat pipes are heat transferring devices that rely on phase change phenomenon to efficiently manage heat transfer between a heat source and a heat sink. Their high effective thermal conductivity makes them ideal for applications where heat needs to be moved across a certain distance with least thermal resistance. Heat pipes offer flexibility in terms of functionality across a wide range of heat loads as well as operating temperatures. They can be bent and manipulated to get around geometric constraints that usually restrict the use of traditional heat transferring mechanisms. Designing an optimum heat pipe will depend on several parameters that include but not limited to the heat load, operating temperature, orientation and geometry. This paper will outline some of the strategies that can be used to select the right heat pipe for a specific application.
Most heat pipes use some sort of wicking structure that enables the liquid to flow from cold end to the hot end due to capillary action of the wick. Bending a heat pipe with the wicking structure inside is tricky and traditional tube bending methods can damage the wick. A proprietary process has been developed at Noren Products Inc., which ensures that the wick maintains its integrity during and after the bending process. Tests have been conducted to compare the deformation of copper tubes due to bending using traditional methods in the industry and the novel method developed at Noren Products Inc. This paper outlines some of the details as well as the advantages of this process compared to traditional bending methods.