In the evaporation section of the heating heat pipe, the working liquid in the die is evaporated by heat and takes away heat, which is the latent heat of evaporation of the working liquid, and the steam flows from the central passage to the condensation section of the heat pipe, condenses into a liquid, and releases latent heat, in the capillary Under the action of the force, the liquid flows back to the evaporation section. In this way, a closed loop is completed, thereby transferring a large amount of heat from the heating section to the heat sink section.
When the heating section is below, the cooling section is on, and the heat pipe is placed vertically, the return of the working fluid can be satisfied by gravity, and the capillary without the capillary structure is called a thermosiphon. The thermosiphon has a simple structure and is widely used in engineering.
Turn left | turn right
Extended information:
First, the basic work
A typical heat pipe consists of a casing, a wick, and an end cap. The inside of the tube is pumped into a negative pressure of 1·3×(10 minus 1-10 minus 4) Pa, and then filled with an appropriate amount of working liquid to make it close to the inner wall of the tube. The wicking capillary porous material is filled with liquid and sealed.
One end of the tube is an evaporation section (heating section), and the other end is a condensation section (cooling section), and an adiabatic section can be arranged in the middle of the two sections according to the application. When one end of the heat pipe is heated, the liquid in the core is vaporized and vaporized, and the steam flows to the other end under a slight pressure difference to release heat to condense into a liquid, and the liquid flows back to the evaporation section along the porous material by the capillary force.
This cycle does not allow heat to pass from one end of the heat pipe to the other end. In the process of realizing this heat transfer, the heat pipe contains the following six main processes related to each other:
(1) heat is transferred from the heat source through the heat pipe wall and the wick that is filled with the working liquid to the (liquid-vapor) interface;
(2) the liquid evaporates at the (liquid-vapor) interface in the evaporation section;
(3) The steam in the steam chamber flows from the evaporation section to the condensation section;
(4) The steam condenses on the vapor-liquid interface in the condensation section:
(5) Heat is transferred from the (vapor-liquid) interface to the cold source through the wick, liquid and pipe wall:
(6) The condensed working liquid is returned to the evaporation section due to capillary action in the wick.
Second, heat pipe classification
Since there are many uses, types and types of heat pipes, and heat pipes have different structures in terms of structure, materials and working fluids, there are many classifications of heat pipes. The commonly used classification methods are as follows.
1, temperature distinction
According to the working temperature inside the heat pipe, the heat pipe can be divided into low temperature heat pipe (-273 - 0 °C), normal temperature heat pipe (0-250 °C), medium temperature heat pipe (250-450 °C), high temperature heat pipe (450-1000 °C), etc. .
2, return power differentiation
According to the working fluid return power, the heat pipe can be divided into a core heat pipe, a two-phase closed thermosiphon (also known as a gravity heat pipe), a gravity assisted heat pipe, a rotating heat pipe, a current body power heat pipe, a magnetohydrodynamic heat pipe, an osmotic heat pipe and the like.
3, the combination of division
According to the combination of the shell and the working fluid, (this is a customary method of division) can be divided into copper-water heat pipe, carbon steel-water heat pipe, copper-steel composite-water heat pipe, aluminum-acetone heat pipe, carbon steel Rong heat pipe, stainless steel, sodium heat pipe and so on.
4, structural form differentiation
According to the structure form, it can be divided into ordinary heat pipe, separate heat pipe, capillary pump circuit heat pipe, micro heat pipe, flat heat pipe, radial heat pipe and so on.
5, functional division
According to the function of the heat pipe, it can be divided into a heat pipe for transferring heat, a heat diode, a heat switch, a heat pipe for heat control, a simulation heat pipe, a heat pipe for cooling, and the like.
source：未知