Experimental study on deflagration of ethanol vapor from pool with different location and area in tunnel

Abstract

Abstracts In this paper, the ethanol vapor deflagration with different fuel pool location and area were experimental studied in a reduced sized tunnel with a size of 3 m✕0.3 m✕0.25 m. There were two fuel pans were set in the tunnel, the first fuel pan with a diameter of 10 cm was fixed in the center of the tunnel, and this one was heated by a PID temperature control heater. The another one (with a diameter of 10 cm or 15 cm) was separately set at 25 cm, 50 cm, 75 cm, 100 cm, and 125 cm according to test conditions. The characteristics of deflagration flame propagation, flame structure and the pressure were analyzed. The study found that the complex liquid-gas two-phase coupling effect was showed during the deflagration progress in the tunnel that the combustible vapor required for the duration of deflagration was controlled by the vapor phase transition process of flammable liquid distributed in the tunnel. The flammable ethanol vapor is a necessary condition for explosion. On the contrary, the flame of explosion promotes the evaporation of ethanol liquid. When the area of the leak source is constant, the explosion pressure and the flame speed decrease as the distance from the leak source to the explosion source increases. When the position of the leak source in the tunnel is constant, the explosion pressure and the explosion flame speed increase as the area of the leak source increases. In particular, when the fuel pan is 25 cm from the center of the explosion source, the overpressure at a fuel pan with a diameter of 15 cm is nearly 2.6 times that at 10 cm, and the flame propagation speed is about 1.2 times.