1.3 Classifications of heat pipe

There are different types of heat pipes, classified based on [4]:

I.Nature of fluid circulation, such as capillary driven, rotating heat pipes, flat plate, two-phase close thermosyphon, etc.

1.5 Difference between wick heat pipe and thermosyphon

aspects such as:

materials.

2. Thermosyphon heat pipe

even against gravity.

Thermosyphon Heat Pipe Technology

DOI: http://dx.doi.org/10.5772/intechopen.85410

The wick and wickless (thermosyphon) heat pipes have many features in common in their construction, operation and applications. However, they differ in some

a.Wick material: unlike in thermosyphon, wick materials are lined on the inner parts of the wick heat pipe. This enables the return of the condensed liquid

b.Orientation of the pipes: the condenser section of the thermosyphon must be located at the top of the evaporator because the return of the condensate is basically by gravity, while in the case of the wick heat pipe, the evaporator can be placed at the top because the return of the condensate is based on the

c. Need of adiabatic section: thermosyphon may or may not have adiabatic section whereas most of the wick heat pipes have it, as to separate the

d.When working fluid is charged into the sealed container, it forms a liquid pool (in case of thermosyphon) while in case of wick heat pipe, it saturates the wick

This is a natural fluid circulation heat pipe which has no wick material presence.

thermosyphon require that the pipe be tilted to an angle from the horizontal for it to

Thermosyphon is a vessel closed at both ends and attached with a small charging pipe placed at one of the ends. The air in the vessel is evacuated creating a vacuum, then charged with working fluid through the charging pipe. The pipe is usually

ii. Adiabatic section (optional): space between evaporator and condenser,

iii. Condenser, where the vapour from the evaporator section of thermosyphon heat pipe is condensed usually by cooling water flowing through a water jacket.

iv. Insulation: the evaporator section is insulated to minimize heat losses.

i. Evaporator, where heat is supplied to the working fluid.

It is a simple heat pipe consisting of a sealed vessel charged with working fluid under a vacuum condition. It is made up of evaporator and condenser sections, sometimes with adiabatic section in between them. The vessel is usually made from aluminium or copper to facilitate high conduction of heat. Unlike wick heat pipe, the condenser of thermosyphon must be at the top, for the condensed liquid to return to the evaporator under gravity. Furthermore, some applications of

capillary effects due to the presence of the wick materials.

evaporation and condensing sections.

have maximum exposure to solar radiation [9, 14–16].

2.1 Construction of thermosyphon heat pipe

where no heat or cooling is applied.

divided into the following sections:

9

