Heat pipe is an efficient thermal transfer device. The functioning principle of a heat pipe [hp] is based on evaporation and condensation cycle of a liquid inside the hp that enables transfer of large quantities of heat along the axis of the hp with a low temperature differential between the evaporator and condenser sections of hp. When heat is transferred from a heat source to the evaporator section of the hp, the liquid in the evaporator evaporates and the vapour moves to the other end of the hp [condenser section] due to the pressure gradient. The vapour condenses due to heat rejection by forced or natural convection. Principle of operation: the condensate returns to the evaporator through a capillary structure provided on the inside walls of the tube. Therefore, the hp can continuously transport the latent heat of vaporisation from the evaporator to condenser. Applications: cooling of semi-conductor devices like diodes, thyristors and igbts in rectifiers, inverters, units and modules of electronic equipment, etc; cooling of control panel and optical cable junction box; cooling of servers/computers/laptop, etc; waste heat recovery in hvac/dehumidifiers and use in grain dryers, tobacco dryers, etc; use in die-casting and injection moulding dies; solar energy applications and also in cryogenics use. Advantages: high heat mum heat transfer capacity because of high thermal conductance; maximum heat flux is achieved with minimum temperature difference; greater design freedom - can be manufactured to suit exact wattage dissipation; higher loading of electronic devices than with conventional cooling; unmatched suitability in higher wattage dissipation segment; provide for 20-40% reduction in weight and physical dimensions.
