1. Large axial heat transfer;
2. The axial and radial temperature gradients are very small;
3. Compared with convection, axial conduction heat can be neglected.
Heat pipe transfers heat through latent heat of phase change, and its thermal conductivity is very high. Due to the excellent characteristics of heat pipe technology, such as high thermal conductivity, excellent isotherm, variability of heat flux density, reversibility of heat flux direction, thermal stability and environmental adaptability, it can meet the requirements of electronic equipment for compactness, reliability and flexible control, high heat dissipation efficiency and maintenance-free. Heat pipe technology plays an important role in aerospace and nuclear industry.
Technical introduction Heat pipe, also known as "thermal superconductive pipe", was first put forward by R. S. Gaugler of Ohio General Engine Company in 1944 in American patent (patent number: 2350348), and Cotter put forward a relatively complete heat pipe theory for the first time in 1965, which laid the theoretical foundation for heat pipe research and became the basis for performance analysis and design of heat pipes. A typical heat pipe consists of a shell, a wick and an end cover. The liquid working medium is heated and evaporated by the heat flow in the evaporation section, and its vapor flows to the condensation section through the insulation 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 condensed liquid gathered in the core of the heat dissipation part returns to the evaporation part through the capillary force of the core, and then absorbs heat and evaporates.