Experimental Study and Analysis of XPS Vertical Countercurrent Fire Spread

Abstract

Abstract In order to study the vertical countercurrent fire spread of XPS with different widths in the space and wall adhesion conditions, the XPS vertical countercurrent fire spread experiment with different widths was carried out by self-made vertical countercurrent fire test platform. It is found that the spread rate and the average flame height of the XPS decrease first and then increase with the increasing of the width under the two working conditions. After the critical point, the countercurrent spread rate without constraint tends to be stable while the countercurrent spread with one side constraint is greatly accelerated. According to the change of the heat flux on the preheating zone, it is inferred that there are two different heat transfer modes in the two kinds of working conditions. The spread rate of XPS without constraint is mainly affected by gas-phase heat transfer. On the Contrary, The spread rate of XPS with one side constraint is affected by gas-phase heat transfer and solid-phase heat transfer. And with the increase of the width, the solid-phase heat transfer gradually replaced the gas-phase heat transfer to influence the heat-receiving area of the preheating area.