A heat pipe is a heat transfer machine that can transport large quality of heat to very small temperature between hotter and colder interface. Heat pipe is a simple device that can quickly transfer heat from one point to another. Heat pipe is in a shape of hollow cylinder which is filled with vaporizable liquid. It works like first heat is absorbed in a evaporating section and fluid boils to vapour phase. Then heat is released from the upper part of the cylinder to the environment.
Now vapour condenses to liquid phase and liquid returns by gravity to the lower part of the cylinder. It may also describe as Heat pipes are having two sections like precool and reheat. The main advantages of heat pipe are the passive heat exchange without any moving parts. The cooling or heating equipment size can be reduced. There is no cross contamination between air streams. Some disadvantages are it require two air streams be adjacent to each other. And the air streams must be relatively clean and may require filtration.
