The Experimental Study On Indoor Combustible Materials Burning Characteristics Of Office Buildings And Its Fire Hazard Analysis

In recent years, along with the industrialization development of new technologyand new materials, the types and quantities of combustible materials in the building isalso increasing. The use of various electrical facilities, upscale furniture anddecoration also brings a potential fire hazard to the office building. Based on thestatistical analysis of the fire load of office buildings, through experimental analysison characteristics of indoor combustible materials as well as full-scale fire experimentto the office building. Using numerical simulation method to study the fire risk ofoffice building.According to the statistics of office buildings fire load, get the fire load densityof office buildings obedience positively skewed distribution; mean fire load density is453.76MJ/m2.Through the heating value experiment measured the calorific value of materialscommonly used in office building. By means of thermo gravimetric analysis, thepyrolysis temperature, maximum weight loss rate, temperature corresponding to themaximum weight loss rate and the final state temperature of various materials isobtained; Material pyrolysis is carried out in several stages, endothermic andexothermic situation in the process of pyrolysis is also obtained. Experimental studythe heat radiation ignition characteristics of white pine, red beech, pinus tabulaeformis,paulownia four kinds of wood under conditions of variable heat. The results show thatmass loss rate of wood in radiation ignition process has three stages: graduallydecreased stage, sharply decreasing phase and relatively stable phase. The qualityvariations of each material in sharply decreasing phase is a significant linear decrease.Surface temperature and CO2contents changes with O2concentration exists similarinverse relationship in the process of material burns, while weight loss rate with CO2contents exists similar relationship.Through small office building indoor full-scale fire experiments, get the changesin temperature and visibility of indoor and corridor in the office building. Flashoveroccurred in9min after the office building on fire, the room temperature up to1155℃. After the fire, indoor smoke at273s fill the entire room, the corridor smokesubsidence to2m from the floor at486s. There is a linear relationship between peaktemperature in corridor and distance from the enclosure door to the measurementpoints, the maximum growth rate of smoke layer temperature in the corridors and indoor were25.63℃/s and20.21℃/s. Flue radiation intensity in the corridor farfrom fire room5m, relative elevation1m is1.79kW/m2.Based on combustion characteristics of office building and small office buildingfull-scale fire experiment, numerical simulation on a small office building is made tostudy the fire risk. Smoke temperature, smoke visibility and CO concentration incorridor and indoor of office building are also analyzed in the simulation. Simulationfound that time to hazardous condition of second floor fire room and corridor is279sand498s respectively. The maximum fire heat release rate and fire hazard indexobtained by simulation are well consistent with the full-scale office buildingexperimental data.The results indicate that FDS can accurately predict the fire hazardof office building.