Subcooled flow boiling under an electric field on surface enhanced by diamond particles deposition

•This study investigated the subcooled flow boiling of dielectric liquid.•The copper boiling surface was electrically deposited with diamond particles.•The boiling curves were compared in the presence and absence of the electric field.•The effect of flow rate and inflow temperature on the boiling curve was studied.•The predictive CHF was derived, and compared with experimental results. This study investigates the development of a high heat-flux cooling device. The subcooled flow boiling performance of a fluorinated dielectric liquid (AE-3000, CF3CH2OCF2CF2H) was experimentally characterized. An electrode fabricated with ten 1000 μm slits was placed at 600 μm above a heated surface, and was energized to generate a high electric field in the gap between the heated surface and the electrode. The heat performance of the heated wall surface, which had undergone co-electrodeposition of diamond particles and nickel, was evaluated at various inlet flow rates (0.97, 1.9, and 2.9 g/s) and initial inflow temperatures (30, 40, and 50 °C). An electric field of −5 kV/mm was applied to the gap, and the performance enhancing mechanisms under electric field were identified. The best enhancement of performance upon electric filed was obtained at an inlet flow rate of 1.9 g/s and initial inflow temperature of 50 °C. Under these conditions, the critical heat flux (CHF) performance reached 120.6 W/cm2 and the heat transfer coefficient was 40.0 kW/(m2 K). A predictive equation derived from the sensible and latent heats failed to predict the expected CHF, once the subcooled liquid suppressed the boiling process depending on the inlet temperature and flow rate.