Film Boiling Heat Transfer Enhancement via Electrostatic Leidenfrost State Suppression

Boiling heat transfer has enormous impact on the effectiveness of various industrial processes like steam generation, desalination, and nuclear reactor operations. Heat transfer in the film boiling regime is significantly reduced as compared to the nucleate boiling regime due to the existence of a vapor layer at the solid-liquid interface (Leidenfrost effect). This vapor layer degrades heat transfer by up to two orders of magnitude and causes dryout, which can result in severe temperature excursions. This work maps out the heat transfer benefits of electrostatic suppression of the Leidenfrost state. Electrical suppression of the Leidenfrost state is observed for a variety of liquids, including organic solvents, water and electrically conducting salt solutions. Successful Leidenfrost state suppression is observed with moderate voltages even at ultrahigh temperatures exceeding 550 °C. Elimination of the vapor layer increases heat dissipation capacity of film boiling by more than one order of magnitude; up to 45X enhancement was measured in this work. This work also introduces the concept of tunable film boiling heat transfer. Overall, electrically-enhanced boiling can enable a new class of technologies for active control and enhancement of boiling heat transfer, with various applications in energy systems.