<p>Bubbly flow or foam flow prevails in the subcooled flow boiling of seawater. Compared with the bubbly flow in the subcooled flow boiling of de-ionized water, the bubble size of seawater is smaller. Further, small bubbly flow or foam flow in subcooled flow boiling of seawater would be affected by different heat flux, mass flux and inlet subcooling. The change in the boiling behaviors due to different conditions can be reflected in terms of variations of bubble characteristics. However, details of the characteristics of bubbles in seawater generated by the two-phase flow boiling are still limited. In the present study, bubble characteristics are measured and detailed by the image analysis method in the software Image J. The subcooled flow boiling experiments with different heat fluxes are conducted in a vertical upward annulus with artificial seawater at the inlet temperature of 90℃. The experimental mass fluxes are controlled at the 1200 kg/m<sup>2</sup>s. The two-phase flow patterns are recorded by the high-speed camera. Ten images are selected as one set of measurement from the videos recording varying two-phase flow behaviors under different heat fluxes to conduct bubble detections in the software Image J. After pre-processing images, measurements of fitting ellipse are conducted. Averaged descriptors of bubbles are obtained, including area, perimeter, major, minor, and aspect ratios, etc. It provides a possible way to investigate the details of bubbly flow or foam flow in the subcooled flow boiling of seawater. &nbsp;</p>

Quantitative Measurements of Bubbles and Foam Flow Generated From Two-Phase Subcooled Flow Boiling of Seawater in a Vertical Annulus

Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE28/volume/85246

2021 28th International Conference on Nuclear Engineering (ICONE28)

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