Experimental study on heat transfer characteristics of ice melting processes under point-source bubble flows

Effective de-icing technologies are important to the ships and offshore structures in cold regions and air bubble de-icing method is expected to have great potential for application. To deeply understand the ice melting process under point-source bubble flows, especially the heat transfer characteristics, an experimental set-up is designed to explore the influence of the flow rate. According to the shape of the ice bottom surface and the distribution characteristics of bubbles, the ice melting process is divided into flat, concave, and holed ice stages. The ice melting efficiency decreases with the increasing flow rate and when the flow rate increases from 0.5 L/min to 2.0 L/min, the ice melting efficiency decreases by 58.0 %. The stage-averaged heat transfer coefficients of the flat, concave, and holed ice stages decrease successively and all of them increase with the increase of flow rate. Correlations for central and global heat transfer coefficients are established to describe the ice melting process, which fits well with the experimental data with a deviation less than +/- 15 %. The findings are helpful to the design and optimization of the air bubble de-icing system.