A heat pipe is a closed evaporator-condenser system consisting of a sealed, hollow tube whose inside walls are lined with a capillary structure or wick. Thermodynamic working fluid, with substantial vapor pressure at the desired operating temperature, saturates the pores of the wick in a state of equilibrium between liquid and vapor. When heat is applied to the heat pipe, the liquid in the wick heats and evaporates. As the evaporating fluid fills the heat pipe hollow center, it diffuses throughout its length. Condensation of the vapor occurs wherever the temperature is even slightly below that of the evaporation area. As it condenses, the vapor gives up the heat it acquired during evaporation. This effective high thermal conductance helps maintain near constant temperatures along the entire length of the pipe.
1.Heat Pipe Operation Principle
2.Heat Pipe Features & Benefits
Tube material: copper
Wick structures: grooved or sintered copper powder
High thermal conductivity
Light weight
Fast thermal response
3.Applications for Heat Pipes
Compact Electronics Enclosures
Aerospace
Medical
Consumer Electronics
HVAC
They are used to transfer heat with minimal temperature difference from the heat source (evaporator) to the heat sink (condenser) as well as to spread the heat across a surface. Many factors have to be considered in choosing a heat pipe for a specific application. The effective length (Leff) is a useful indicator of the length of a heat pipe as employed in a specific application (accounting for evaporation and condensation lengths). Heat pipes come in round or flat shapes. Flat heat pipes are easier to attach to heat dissipating components while the round heat pipes offer advantages for certain fin configurations at the condenser end.
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