Evaluation of Thermal Radiation Blocking Effect of Water Mist Curtain in Fire of Hazardous Material Storage Tank

Abstract

In this study, the thermal radiation blocking effect of a water mist curtain in a full-scale hazardous material storage tank fire was numerically simulated. A fire dynamics simulator (FDS) was used for the numerical simulation, and the accuracy of the heat flux prediction of the FDS was verified using an earlier experimental study on a full-scale hazardous material storage tank fire. Subsequently, a water mist curtain system was installed in a full-scale hazardous material storage tank, and the effects of fire source conditions and water mist curtain characteristics on the heat flux and thermal radiation blocking rate of the water mist curtain were examined. The results of the numerical simulation showed that the water mist curtain decreased the heat flux and increased the thermal radiation blocking rate when the fire source was a tank and dike and when the nozzle had a large spray angle and a small droplet size. Near the adjacent protected tank (in the height of 2∼14 m from the ground at the nozzle installation position), the thermal radiation blocking rate of the water mist curtain was measured to be 62.5∼72.4% and 33.5∼67.4% for the tank and dike fire and the tank fire, respectively, 62.5∼72.4% and 54.4∼65.3% for the spray angles of 180° and 90°, respectively, and 62.5∼72.4% and 71.2∼83.0% for the droplet sizes of 400 and 200 µm, respectively. This study confirmed that the water mist curtain could effectively block the thermal radiation from the fire tank to the adjacent tanks during a full-scale hazardous material storage tank fire.