Simultaneous visualization of dry spots and bubbles for pool boiling of R-113

A visualization study on the behavior of bubbles and dry spots has been carried out for pool boiling of R-113 on a horizontal heater. The behavior of bubbles and dry spots is recorded simultaneously. From video imaging and image processing analysis, the formation of bubbles and dry spots occurs simultaneously, and therefore they should be considered as a synchronized concept rather than independent identities. The dry spot density is equivalent to the active site density in the region before CHF. In this study the boiling phenomena near CHF are different from the so-called macrolayer dryout model