Heat pipe cooling technology
time:2021-01-08 16:17 author:Heat sink design click:
Heat pipes, also known as "thermal superpipes", were first proposed by R. S. Gaugler of Ohio General Motors in 1944 in the U.S. Patent (No. 2350348). In 1965, Cotter first proposed a more complete thermal management theory, which laid the theoretical foundation for heat pipe research and became the basis for heat pipe performance analysis and heat pipe design.
A typical heat pipe consists of a shell, a wick and an end cap. The liquid working fluid is heated and evaporated by the heat flow in the evaporation section, and its vapor flows through the adiabatic section to the condensation section. In the condensation section, the steam is cooled by the cold fluid outside the tube to release latent heat and condense into liquid. The condensate accumulated in the liquid wick in the heat dissipation section returns to the evaporation section and then absorbs heat and evaporates with the help of the capillary force of the liquid wick.
The heat pipe has the following characteristics when working:
1. Large axial heat transfer;
2. The axial and radial temperature gradients are very small;
3. Compared with the convection, the axial heat can be omitted.
The heat pipe transfers heat through the latent heat of phase change, and its thermal conductivity is very high. Because the heat pipe technology has excellent characteristics such as extremely high thermal conductivity, excellent isothermality, heat flow density variability, heat flow direction reversibility, constant temperature, and environmental adaptability. It can meet the requirements of electronic equipment for compact heat dissipation devices, reliable and flexible control, high heat dissipation efficiency and no maintenance. Heat pipe technology plays an important role in the aerospace and nuclear industry.