Study On Fire Spreading Behavior Of Polyurethane Insulation Material In The Complex Building Environment

With the continuous deepening of China’s ecological civilization construction,the historical task of comprehensive energy conservation and emission reduction has become the focus of society.As one of the traditional high-energy consumption and low-energy industries,the construction industry has become the pioneer of the reform of energy conservation demonstration and is facing comprehensive industrial transformation and systematic structural upgrading oriented by green energy conservation.In recent years,the laying of insulation materials as the main means of achieving green building energy-saving,including polymer insulation materials is one of the most widely used material for building energy conservation field,the high polymer material on the one hand has small density,low cost,good thermal insulation performance,on the other hand,there are flammable and combustible spread fast speed,the high heat release rate of fire hazard,become the inventors of the building insulation materials fire accident in recent years.Modern high-rise buildings are usually densely populated,small activity space,and the external wind environment is complex and changeable,and building facade polymer insulation material fire accident is generally spread fast high heat release fire risk.So far,the research on the fire spread characteristics of polymer materials at home and abroad is not comprehensive,and the relevant experimental data and theoretical model can not meet the technical requirements for fire prevention and control in the field of modern building insulation.Therefore,the research on the fire spread behavior of polymer insulation materials has become an important topic to be solved at present.Flexible Polyurethane(FPU)foam,as a common polymer insulation material,is widely used in building facade walls.However,once the external protective layer of the facade walls breaks and falls off,the exposed FPU materials in the environment will ignite rapidly when exposed to an open fire or heat source,resulting in a greater fire risk.This article in view of the modern high-rise building facade actual characteristics of fire insulation materials,building experimental platform,small size experiment investigation from the installation of the heat preservation material characteristics and environmental factors two perspectives,simulation analysis of the material under lateral wind effect,curtain wall installation Angle under the configuration and spacing of curtain wall lateral wind effect for these three architectural heat preservation material FPU elevation fire spreading behavior and the effect of the combination of the theoretical model,the former research about the spread of fire behavior inference material leading mechanism and development trend of fire spreading behavior,makes every effort to perfect the building insulation materials fire spread the research content,It provides a reference for the fire safety design of modern building facade.Experimental study and data analysis,under the environment of natural convection,FPU vertical fire spread in the process of pyrolysis forward,form a "V" pattern,with the increase of lateral velocity of flame front appear tilt and sticking in the facade,windward characteristic length are mounting and the leeward side of the pyrolytic striker falling pyrolysis striker eventually disappear;The special melting and dropping phenomenon of polymer material combustion is very unfavorable to fire rescue,and with the increase of lateral wind speed,the dropping rate of molten material increases continuously,which also means that the high-temperature molten material is easier to escape from the flame zone and form secondary disasters.The sandwich structure formed between the glass curtain wall configuration and the facade wall creates favorable conditions for the formation of the chimney effect.The accelerated air convection inside the sandwich makes the temperature in the middle part of the vertical material significantly lower than that on the two sides.In the curtain wall configuration,the original "inverted V-shaped" pyrolysis front in the fire propagation process of FPU gradually develops into a one-dimensional linear distribution under the action of lateral wind,and the propagation rates of both windward and leeward sides increase with the increase of lateral wind speed.The results of this study provide a practical basis for the study of the combustion pyrolysis and fire spread behavior of building polymer insulation materials,provide theoretical support for the evaluation of the fire risk of building facade insulation materials,and further lay a foundation for the facade fire prevention and control work under the curtain wall architecture.Figure [35] Table [7] Reference [91]...