The heat pipe is a conveying mechanism capable of carry […]
The heat pipe is a conveying mechanism capable of carrying a heat flux of 10 W / cm2 to 20 kW / cm2 at a very fast speed. They can be considered superconductors in nature. The heat pipe may be used as a means of transferring heat from one location to another, or as a means of an isothermal temperature distribution.
Heat pipes have been used for a variety of applications such as laptops, spacecraft, plastic injection molding machines, medical equipment and lighting systems. The operation of the heat pipe is shown in Fig.
The heat pipe has three parts: the evaporator, the adiabatic and the condenser. The inside of the tube is covered with a core, and the tube is partially filled with a liquid such as water. When the evaporator portion is exposed to a heat source, the internal liquid evaporates and the pressure in the portion increases. The increased pressure causes the vapor to flow to the condenser portion of the heat pipe at a rapid rate. The steam in the condenser section dissipates heat to the bulk radiator and is converted into liquid by transferring the latent heat of the vapor to the condenser. The liquid is then pumped back to the evaporator by the action of the core suction capillary. The intermediate portion of the heat pipe has a very small temperature difference.
The heat pipe is a closed evaporator-condenser system consisting of a sealed hollow tube with a capillary structure or core on its inner wall. The thermodynamic working fluid with significant vapor pressure at the desired operating temperature saturated the pores of the oil core in a balanced state between the liquid and the vapor. When heat is applied to the heat pipe, the liquid in the oil core is heated and evaporated. When the evaporation fluid fills the hollow center of the heat pipe, it spreads over its entire length. The condensation of vapor occurs at a temperature or even slightly lower than the temperature of the evaporation zone. When steam is condensed, the vapor evaporates the heat it gets during the evaporation process. This effective high thermal conductivity helps keep the temperature close to the entire length of the pipe.
The radiator is mounted on a portion of the heat pipe such that condensation occurs at the heat transfer point and a vapor flow pattern is established. The capillary action in the chip returns the condensate to the evaporator and completes the operating cycle. The system is validated in aerospace applications where the heat transfer is the energy-to-energy ratio that can be achieved by its highest efficiency for solid conductors.