The Heat Pipe is a two-phase passive heat transfer device with high conductivity.

It is a vacuum-tight structure consisting of three different components. These components are a working fluid, a wick structure and an envelope. The section where heat input is located is called evaporator, the section where heat is transferred is called adiabatic and the section where heat is removed is called condenser. The heat input evaporates the working fluid in the evaporator section. Saturated vapor, carrying the latent heat of vaporization, moves towards the cooler condenser section.

In the condenser section, the vapor condenses and releases its latent heat. The condensed liquid passes through the inner surface structure under the influence of capillary forces and gravity and returns to the evaporator. Phase change processes and two-phase flow cycles continue as long as the temperature gradient between the evaporator and condenser zones is maintained.

Solid conductors such as copper, graphite, diamond, aluminum and gold have thermal conductivities ranging from 200 W/mK to 1,500 W/mK, while Heat Pipes have thermal conductivities ranging from 5,000 W/mK to 100,000 W/mK.

Heat Pipes have many advantages in their areas of use: