Experimental Study on Cross-ventilation Compartment Fire in the Wind Environment

Abstract

When fire occurs in the rooms of high-rise buildings, the strong ambient wind will play an important role in fire spread and smoke movement behavior. However, wind effect on compartment fire in cross ventilation condition has not been fully studied so far. In the present study, an effort has been made to study crossventilation compartment fire in the wind environment through experimental investigations. The experimental fire was generated by 250ml (10cm×10cm tray burner) or 500ml (20cm×20cm tray burner) nheptane on the floor of a cube enclosure with two opposite vents on the walls. The inside and outside gas temperature profiles at different vertical and horizontal locations were recorded by two thermocouple matrixes. The ambient wind velocity was set to zero, 1.5m/s and 3m/s. It is observed that the ambient wind has two contradictory effects on the compartment fire: promoting fire severity by more oxygen supplying and cooling the fire by heat removing and combustible gases diluting. The spilled-out flame/plume extends horizontally farther with the increase of wind speed. It is found that the compartment fire with 500ml fuel reaches post-flashover stage while that with 250ml doesn’t. The wind effect is obviously observed in larger fires while not significant in smaller fires.