Fire Suppression Performance of a Water Mist System Using Ultrasonic Waves

Conventional water mist systems require high-pressure pumps and complex piping networks to generate fine water droplets, which often results in high installation costs and maintenance difficulties. Recently, a water mist system with ultrasonic waves has been proposed as a viable alternative system to address those limitations. However, there is a lack of experimental data for evaluating the fire suppression performance of water mist systems using ultrasonic waves. Therefore, in this study, a simplified water mist system with an ultrasonic wave was suggested for evaluating the fire suppression performance. Subsequently, a reduced-scale room corner test (RCT) was conducted to investigate suppression performance under various fire sizes and suppression conditions. The experimental cases were classified according to pool size, door condition, and operation of the ultrasonic water mist system. Ultimately, fire suppression performance was quantitatively evaluated using performance indices derived from fire duration and indoor temperature variation. The results demonstrate that the ultrasonic water mist system effectively suppresses fires through combined cooling and oxygen-blocking effects, while significantly reducing indoor temperature compared to oxygen-blocking suppression. The proposed performance indices enable quantitative comparison of suppression effectiveness and confirm the feasibility of ultrasonic water mist systems as an alternative to conventional high-pressure water mist systems.