Experimental Study on the Enhancement of Boiling Heat Transfer Performance Under the Condition of the Downward Heating Surface by an Electric Field

This paper experimentally investigated the impact of the electric field strength (E), electrode installation heights (H), and the electrode shape on enhanced pool boiling heat transfer performance under a downward heating surface with an electric field. It is observed that the critical heat flux (CHF) generally increases with increasing electric field strength. For instance, for the mesh electrode, the CHF is increased by 100.0%, 240.0%, 340.0%, and 440.0% at E = 0.35 × 10⁶ V/m, 0.70 × 10⁶ V/m, 1.05 × 10⁶ V/m, and 1.40 × 10⁶ V/m, respectively, compared to E = 0 V/m. Furthermore, the electrodes hinder the detachment of vapor bubbles, which becomes more pronounced when the electrode installation height is low. At the same time, the more micro-ribs of the electrodes and the denser the distribution, the more uniform the electric field generated. Under this condition, the “pinch-off effect” caused by the non-uniform electric field is reduced, which is more conducive to enhancing boiling heat transfer performance. Ultimately, at H = 5.0 mm and E = 1.40 × 10⁶ V/m, the CHF with grid electrodes improved by 101.1% compared with the horizontally upward without the electric field, which is a superior combination of working conditions and suggests that a more optimistic boiling heat transfer performance can be obtained in microgravity. This work provides guidance for enhancing boiling heat transfer in microgravity by an electric field.