The thermosyphon is simple but effective heat transfer devices. It is a vertically oriented wickless heat pipe with liquid pool at the bottom. Working fluid transports a large amount of heat from evaporator to condenser section. Heat enters through the evaporator section, then generated vapor rises and passes through the adiabatic section and reaches to condenser section. In the condenser, vapor condenses and gives up its latent heat. The condensate backs to the evaporator section by natural gravitational force [1]. A schematic of the working principle of the thermosyphon is shown in Figure 1.
Thermosyphon have been successfully used for waste heat energy recovery in a wide range of engineering applications, such as heating, ventilating, air conditioning systems, ground source heat pumps, water heating systems, aerospace and electronics thermal management [2]. The thermal performance of thermosyphon is affected by several factors, such aspect ratio, inclination angle, filling ratio, working fluid, geometries and power input [3]. These factors have been attempted to examinned by numerous studies that in order to improve thermosyphon performance [4-9].
The present research is an experimental study the heat transfer characteristics of thermosyphon with vacuum chamber which installed on adiabatic section. Therefore aimed to investigate the effects of evaporator length and vacuum chamber diameter, operating temperature, working fluid and also inclination angle. Results may provide further information for improve the performance of the thermosyphon.