I'm studying on heat transport and flow characteristics of a Top-Heat Mode Loop Thermosyphon(model and schematic diagram). 　
　　 Thermosyphons are heat transport device which can transport heat from lower to higher positions by utilizing the body force (e.g. gravitational force and centrifugal force).Therefore, they can work without supplying any external power and are very simple structure. However, although this heat rectifying action having thermosyphons(i.e. limiting a heat flow to one direction. In thermosyphons, the heat is transported in the opposite direction to body force) are advantage, it may become disadvantage depending on the application. Because, for example, in performing thawing and air conditioning system by use of solar energy, since the heat source is positioned in the upper part, thermosypons that having the heat rectifying action can not use in such the application. So, for these applications, a both-directions type heat transport device(i.e. a device which can transport heat from higher to lower positions(top-heat-mode) or lower to higher positions(bottom-heat-mode))is needed.
Thus far, cappillary pumped loop(CPL) heat pipe, anti-gravity thermosyphon, anti-gravity heat pipe and osmotic heat pipe were designed as the top-heat-mode heat pipe, and alarge number of investigations have been carried out. However, although these devices have high completeness, it is not utilized widely. Because they have problems. So, as the top-heat-mode heat pipe that solved these problem, we have developed the top-heat-mode loop thermosyphon in 1999.
　　 The top-heat-mode loop thermosyphon is a top-heat-mode heat pipe that as the driving source of returning the working fluid, using the gravitational force same as the thermosyphons and buoyancy of gas-liquid two phase fluid. Also, since the equipment consist of only pipe, it is very simple structure. Therefore the present device may considered to become an ideal heat transport device that maintenance free and have high trustability, furthermore, with sufficient heat transport performance as not yet seen in above devices.