Effect of Sophorolipid-Containing Fine Water Mist on the Diffusion of Fire Smoke in Longitudinally Ventilated Tunnels

In order to improve the effect of traditional water mist on blocking high temperature flue gas and toxic gas in long and narrow space buildings. In this study, an environmentally friendly EMI dust suppressant with a main component of Sophorolipid was added to the water source to carry out a reduced-size fire smoke suppression experiment. Research revealed that at a wind speed of 1.5 m/s, the maximum smoke suppression efficiency for fire sources of 7.5 kW and 15.7 kW was 67.4% and 46.8%, respectively. The lowest CO concentrations recorded were 45.0 mg/m³ and 87.0 mg/m³, respectively. And the decrease of 83.3% in SO² concentration was observed under the 7.5 kW fire source. With the increase of EMI addition concentration, the concentration of soot particles decreased gradually, and then the rate of decline slowed down. The single-row nozzle water mist curtain is easily affected by the longitudinal exhaust air. When the double-row nozzle is used, the highest smoke suppression efficiency of the two fire sources is 65.0% and 74.2%, respectively. Small particle size droplets will be vaporized by the high temperature of the fire source, reducing the droplet sedimentation rate, and the environmental droplet density should be appropriately increased.