Bubble behavior in subcooled flow boiling of water at low pressures and low flow rates

This study presents experimental data for subcooled flow boiling of water at pressures from 1.05 to 3 bar, bulk liquid velocities ranging from 0.08 to 0.8 m/s, and subcooling from 10 to 30 K. Experiments were carried out on a vertical, annular test section with inner heating surface and upward water flow. High-speed photography at rates of 6000-8000 frames/s captured bubble behavior from inception to collapse, bubble shapes during lifetime, detachment from the wall and typical bubble size. Bubble growth and condensation rates, and variation of bubble lifetime and size with flow rate, subcooling, heat flux and pressure were, further, examined and new correlations proposed. (C) 2001 Elsevier Science Ltd. All rights reserved.