This work has studied the boiling heat transfer mechanism in a pump driven loop thermosyphon system. The coolant is Freon R134a which flows and boils in a tube with inside diameter of 8.05 mm. The results show that at a constant heat flux, the boiling heat transfer coefficient is not influenced by the coolantâ€™s mass flow rate. In other ward, the boiling mechanism at this situation is the nucleate boiling instead of the convection boiling.
Keywords Boiling mechanism, Nucleate boiling, Pump driven, loop thermosyphon