Controlled heat pipes

The presently available kinds of controlled heat pipes are discussed in general terms, and several equations which are beneficial to the understanding of the operation of such pipes are given. Heat tubes employing noncondensing gas are used as devices for maintaining certain objects at constant temperature, since they provide constant temperature over a large part of the surface. Centrifugal heat pipes are of great interest. They can be subdivided into two types: rotating heat pipes, and heat pipes with swirled flow of vapor or vapor-liquid mixture, for example, by a swirl generator placed inside the tube. Great promise in controlling heat and mass transfer is held by coaxial heat pipes, in which the thermal energy is transported radially.