Experimental and numerical investigation of the impact of operating conditions on water electrolysis with ultrasonic

The hydrogen and oxygen bubbles covering the electrode surface will reduce the reaction rate of water electrolysis and increase energy consumption. Adding ultrasonic to the electrolytic cell can improve the escape velocity of bubbles on the electrode surface by oscillation and cavitation effect. In this paper, the effects of ultrasound on the performance of water electrolysis under different working conditions are studied by experiment and numerical simulation. Firstly, the polarization curves and bubble flow patterns under different positions of the ultrasonic vibrator and electrode were obtained through experiments. And then, the flow model of the electrolytic cell with ultrasonic is constructed, which considers the mass transfer between the gas and liquid phases and the acoustic flow phenomenon caused by cavitation. The results revealed that, due to the reflection of the wall and the transmission process of the ultrasonic in the electrolyte, the electrode position has a significant impact on the current density when the ultrasonic vibrator is located on the right side of the electrolytic cell, which can be increased by 2.40%-22.70% at different electrode positions compared with that without ultrasound. The influence of operating parameters on the flow field inside the electrolyzer was obtained through numerical simulation. As a result, appropriate loading methods and operating conditions can maximize the effectiveness of ultrasound.