High value of critical heat flux allows for effective use of loop thermosyphons (LTS) in different applications. Among them there is thermal control in ancillary systems such as fuel cartridges, heat recovery devices (co-generation and tri-generation), in stationary fuel cell/sorption heat pump systems.

LTS transports thermal energy from a heat source to a sink by natural two-phase convective circulation without any external power supply (no electric pump). Evaporator and condenser of LTS are installed separately, but connected to each other by small diameter bendable (flexible) pipes (liquid and vapor lines). An optimal choice of evaporator and condenser material (carbon-steel, copper, aluminum and recently reinforced polymer tubes) and working fluid (propane, R-134a, R-600, ammonia, water) gives possibility to obtain high heat transfer characteristics.

Developed LTS with the flat copper evaporator (thickness is 3 mm) is capable to transport 100W at the temperature of the adiabatic zone less 100 ^oC. The thermal resistance of LTS is 0.03K/W.