A two-phase closed thermosyphon is a heat pipe needing no
wicks to return the condensate working fluid from the condenser
section to the evaporator due to gravity. However, the evaporator
must be positioned at the lower part of the gravitation field (compared
to the condenser). The operation of a thermosyphon is sensitive
to the fill volume of the working fluid. For thermosyphons,
it has experimentally been shown that the maximum rate of the
heat transfer increases with the amount of the working fluid up
to a certain value. Because of its simple structure, stable operating
conditions during steady state, the characteristic of a thermal
diode and its wide operating temperature range, it has been applied
to many industrial fields. Applications such as: heat exchangers,
cooling of electronic components, solar energy systems,
deicing and snow melting [1].