Definition of heat pipe and heat pipe principle
Heat pipe according to the more precise definition, should be called a "closed two-phase heat transfer system", that is, within a closed system, relying on phase change of the fluid (liquid turns into a vapor phase or vapor phase liquid phase) to the heat transfer means. As we all know, when a medium from the liquid into a vapor phase (water evaporation or boiling), will absorb heat; and when the medium from the vapor phase into the liquid phase (such as steam condensation), will release heat. Within these two processes cleverly combined and placed in a closed container, they constitute an advanced heat pipe heat transfer components --- a.
The typical structure of the heat pipe. A cylindrical container, the interior lined with a porous material, the inner container is evacuated to a degree of vacuum, and then injected into a volume of liquid (medium) and the container is sealed. Thus, a heat pipe, it may lead.
The typical structure and working principle of the heat pipe
If one end of the heat pipe is heated, and the other end of the cooling, or insulating material intermediate separator to separate the two, so that the heat pipe inside the two-phase heat transfer process will begin. Heating section of the media will be boiling or evaporation, absorption of latent heat of vaporization from liquid to vapor. Steam generated in the inner tube of a certain pressure effect, the flow of the cooling section, encountered the cold wall of steam will condense into a liquid, and release latent heat of vaporization, to pass through the outside wall of the cold source. Capillary force condensed liquid rely inner wall of the porous material produced by heating return flow section, an endothermic process again starts to evaporate. Thus, through the tube becomes continuous phase medium, the continuous transfer of heat to complete.
When the heat pipe on the ground application, allows gravity to help condensate return, then, it does not wick inside the tube, as long as the heat pipe tilted or vertical position, allowing the heating section at the bottom, the cooling section at the top you can a. Such a heat pipe called gravity or gravity assisted heat pipe heat pipe. Heat pipe heat exchanger described below, are used in the vast majority of the gravity heat pipe.