An experimental study was performed to observe bubble behaviors and heat transfer mechanism of pool boiling of refrigerant R-113 at pressure 0.1 MPa.A transparent heater was used to observe bubble behavior on the entire heater surface with a high-speed camera placed beneath the heater surface.The departure diameter

departure time of bubbles and nucleation density at different heat fluxes were obtained. As a bubble grew up

the dryout area of microlayer under the bubble could be observed.It was also observed that there was no liquid recruit into the microlayer in the experiment.Even at a very high heat flux

vapor stem could not be observed

and the periodic generation and growth of primary vapor bubble is dominant. The relationship between nucleation density and heat flux was given.Based on the experimental results

boiling curve for R-113 was predicted by using the dynamic microlayer model.As a result

the agreement between the predictive result based on the dynamic microlayer model and the experiment data for boiling curve of R-113 is excellent.