THERMO-VISUAL INVESTIGATION OF A TWO-PHASE CLOSED LOOP THERMOSYPHON

An experimental investigation on heat transfer characteristics for an evaporator of a two-phase closed-looped thermosyphon was carried out. Experiments were conducted using three different evaporator surfaces, namely Pin Finned Surface (PFS), Rectangular Finned Surface (RFS) and Plain Surface (PS) with three different working fluids Acetone, Ethanol and Methanol. Bubble generation frequency and bubble density per unit area were estimated. A fan of 40 W capacity was used to know the forced convection effects on condenser for heat flux. The average heat flux can be increased to approximately 150 % by using the condensing fan. The experimental results show that the heat transfer increases by 150 % for Ethanol with respect to Acetone and this value is 30 % with respect to Methanol. It was found that Rectangular Finned Surface (RFS) can transfer about 30% more heat than Plain Surface and approximately 15 % more than Pin Fin surface.