Bulk Boiling

Since system temperature rises or system pressure drops, the bulk fluid can attain saturation conditions. At this point, the bubbles incoming to the coolant channel will not fall down. The bubbles will tend to unite together and form bigger steam bubbles. This phenomenon is termed to as bulk boiling. The bulk boiling can give sufficient heat transfer given that the steam bubbles are carried away from the heat transfer surface and the surface is constantly wetted with liquid water. Whenever this can't take place film boiling outcomes.