Abstract
A Loop Thermosyphon has been designed, fabricated and tested to investigate the heat transfer characteristics by two-phase natural convection. The rig was made from copper tubes connected with each other in closed loop including four main parts: vertical evaporator located in the bottom of the device and surrounded by an electrical coil heater as a heat source ,a horizontal condenser located in the upper part of the device cooled by water, vapor rising adiabatic tube and condensate return adiabatic tube. In this research the effect of heat input and filling ratio of the evaporator on the heat transfer coefficient and temperature distribution on the loop surface was verified experimentally using distilled water as working fluid at operating pressure near-atmospheric pressure. The maximum heat transport capability for evaporator was found to be equal to (3424 W/m2 oC). A comparison between the present work results with empirical and theoretical correlations of other researchers showed good agreement.
