Study On Toxic Fire Smoke Of Common Combustible Building Materials

Smoke generated in fire disaster is the main reason to cause death. The statistical data shows that more than 75% death is caused by inhaling the toxic smoke to induce asphyxia, in building fire disaster. With the economic development, the number of the large supermarket,theater,and cabaret etc, those kind of comparatively crowded places, is lager and larger. It's more easily to cause ultra large fire disasters in these places. Thus, it will be necessary to explore the toxic components, proportions and toxic effects in the toxic materials released in the fire disaster.The thesis analyzes building fire disaster, explores the law and reasons of ultra large fire disaster causing heavy casualties, and examines the damages of fire smoke. Furthermore, it also introduces the method of smoke toxicity study, and the assessment indicator and mode. On that basis, the thesis studies the concentration change of CO and CO2 generated by combustible materials in building fire disaster under different conditions, by using theoretical and empirical study, combined with computer simulation.The present study selects the cotton fabric and three common and widely used wood, namely pine, basswood, and fir, to be the subjects of the study, and adopts gas chromatograph to monitor the concentration change of CO and CO2 produced by the selected materials under different heating rate (5℃/min,10℃/min),and air flow (90ml/min,180ml/min).The results show that: Cotton fabric produces less CO and CO2, and slower than wood. The ignition characteristics, law and production of CO and CO2 are insignificantly different among three woods. Pine produces most smoke and basswood least. Heating rate and air flow have great effect on the production of CO and CO2.With the FDS procedure, the thesis simulates smoke layer temperature change and the concentration change of CO and CO2 from different positions in a single room when it's open and closed respectively, by using. The results suggest that:Smoke layer tempreture is higher, and seriously harmful to human, when the single room is both open and closed. Concentration of CO and CO2 near the window is highest. This suggests that CO has transfer capacity, and it's not true that concentration is highest in the fire source; and concentration of CO and CO2 in high position is more intense than in the low position.The present study represents a useful effort to select the building materials, and has guiding signicance to study the damage caused by fire disaster smoke.