Experimental Study On Combustion Of Extruded Polystyrene Insulation Board And Its Suppression With Water Mist Influenced By The Width

Extruded polystyrene(XPS)is a widely used organic thermal insulation material,but it has great fire risk,which is reflected in:1.Low ignition point and rapid spread after ignition;2.Shrinking,melting and dripping afer being heated,forming flowing fire and pool fire;3.A large amount of smoke produced by combustion,including a va-riety of toxic gases.In recent years,fire accidents caused by organic thermal insulation materials have caused serious damage to people's life and property safety,social econ-omy and environment.Therefore,it is of great significance to carry out experimental researches on combustion characteristics and fire suppression of organic thermal insula-tion materials,providing guidance for their scientific application and fire extinguishing.In this paper,XPS boards with three different widths,i.e.,5cm,10 cm and 15cm,were used as samples for relevant researches.The research contents of this paper are mainly divided into three parts:1.XPS combustion characteristics research,including flame propagation rate,flame height,extinction coefficient of smoke and its gas compositions,the function of mass versus time and burning rate function;2.Optimizing the preliminary model of room fire smoke settlement by proposing the method of room geometric reconstruction and heat release rate reconstruction of fire source,and introducing two parameters ?1 and ?2 for charac-terization;3.Test experiments on the suppression/extinguishing effect of water mist on XPS fire.Under conditions of different widths,the experimental results of the above research contents show good regularity,which reflected the width effect on XPS com-bustion.In order to have a deep understanding of the research contents and provide scientific answers to them,two parts of experiments were carried out here,namely the combustion experiment and the fire extinguishing experiment.Using a combination of experiment and theoretical analysis,the combustion behavior of XPS,the influencing factors of room fire smoke settlement and the effect of water mist on XPS fire were revealed.The experimental results show that the relationship of mass change versus time conforms to the form of stretched exponential function,the volume concentration of CO in the air is relatively stable near 50ppm,the geometric reconstruction and heat release rate reconstruction methods can reduce the prediction deviation of room fire smoke settlement model caused by unbalanced heat loss of fire source,and the water mist has a very good extinguishing effect on XPS pool fire,yet it has a poor extinguishing effect on solid wall fire.