subject: The History And Origins Of Modern Heat Pipe Technology [print this page] A heat pipe heat exchanger is a straightforward device which is used to transfer heat from one place to another, using an evaporation-condensation cycle. Heat pipes are referred to as the "superconductors" of heat due to their quick transfer ability with low heat loss. The whole entire process only utilizes three major components which are the container, the working fluid inside the pipe and the thermosyphon effect, also called the capillary structure. But before studying the specific details of exactly how the heat pipe works, it is best to understand the history of heat pipe technology to obtain a solid "feel" of its mechanism and just how it differs from other comparable devices.
The history of the heat pipe can be traced back to Angier March Perkins who in 1839 got a patent on the hermetic boiler tube. He toyed with the idea of a working fluid, but in only one phase and at a high pressure. His descendant, Jacob Perkins, also took a patent on the Perkins Tube (1936) in which a long, twisted tube filled with water was passed over an evaporator and then a condenser. In this situation the water inside operated in two phases. These very early designs also relied on gravity so the water would travel back to the evaporator, but nevertheless they were a sufficient jump-start for present heat pipe technology.
The concept of the modern-day heat pipe was first put forth by R. S. Gaugler of General Motors Inc. in 1944. He patented a light-weight, heat transfer instrument which was supposedly applied to a refrigeration system. He added the concept of using a wick to make the inner fluid return back to the evaporator, instead of gravity. But throughout that period there was no real need for such a thing, so the invention made no impact for about two decades. It resurfaced only during 1962 when G. M. Grover and his co-workers from the Los Alamos Scientific Laboratory built prototypes on the design and coined the name "heat pipe".
By this time the principle of such a thing was established as beneficial in different fields, so heat pipe technology became popular. Industries and laboratories started using heat pipes for different things. Though at first water was utilized as the working fluid, some other substances (i.e. mercury, ethanol, and nitrogen) were ultimately utilized to replace it, depending on the operating vapor temperature range. Throughout 1969, NASA, space agencies and some other aircraft companies expressed interest in using heat pipes to regulate spacecraft temperature.
