The heat pipe is a two-phase heat transfer device with very high effective thermal conductivity. It uses the high vaporization heat of fluid to achieve extremely efficient heat transfer. The heat pipe is composed of a shell, a core structure, and a small amount of working fluid.
Working principle of heat pipe:
Heat is input into the so-called "evaporator". Heat boils the fluid and pushes the fluid vapor to the cooler region of the heat pipe. The cooler area usually coupled to the heat sinks is called the "condenser". The fluid releases its latent heat and condenses back to the liquid, which is again absorbed by the wick structure. Then, the core structure passively pumps the liquid back to the evaporator. The whole operation results in a very low-temperature difference in the length of the heat pipe.
The heat pipe heat sinks have the following advantages:
① The thermal response speed is fast, and its ability to transfer heat is more than 1000 times greater than that of copper tubes of the same size and weight;
② Small size and lightweight;
③ High heat dissipation efficiency can simplify the heat dissipation design of electronic equipment, such as changing air cooling to self-cooling;
④ No external power supply is required, and no special maintenance is required during operation;
⑤ It has good isothermal properties. After heat balance, the temperature gradient of the evaporation section and cooling section is quite small, which can be approximately regarded as 0;
⑥ The operation is safe and reliable without polluting the environment.
Applications of heat pipes.
1. Heat pipe technology was previously widely applied in aerospace, military industries, etc. Since it was introduced into heat sink manufacturing, people changed the design thinking of traditional heat sinks and got rid of the single heat dissipation mode that relied solely on large air volume motors to achieve better heat dissipation. Using heat pipe technology, even if the heat sink uses a low-speed, low air volume motor, it can well solve the noise problem that plagues air-cooled heat dissipation, opening up a new world in the heat dissipation industry.
2. Heat pipes can be made into thermal diodes or thermal switches. The so-called heat diode is to allow heat to flow in one direction only, and not in the opposite direction.