Studied the changes of heat physical parameters, gas concentration of O_2, CO,CH_4 and H_2, and temperature through full scale wood fire experiments in a tunnel and simulationby FLUNET, a kind of computational fluid d...Studied the changes of heat physical parameters, gas concentration of O_2, CO,CH_4 and H_2, and temperature through full scale wood fire experiments in a tunnel and simulationby FLUNET, a kind of computational fluid dynamics software.The results showthat the wood fire experiment and simulation are both oxygen-enriched combustions,which show that the simulation results coincide with the experiment.The results also provethat it is difficult for oxygen-enriched combustion to cause secondary disasters.Somesuggestions were put forward to prevent the occurrence of secondary disasters effectively.展开更多
To investigate the charring rate of timber beams exposed to three-side fire, a total of fifteen new and used Douglas-Fir timber beams in four groups exposed to three-side fire were experimentally studied, together wit...To investigate the charring rate of timber beams exposed to three-side fire, a total of fifteen new and used Douglas-Fir timber beams in four groups exposed to three-side fire were experimentally studied, together with the finite element analyses of the temperature distribution in the beam section. The durations of fire exposure were 0 (on a test piece), 10, 15, 20 and 30 min, according to the ISO 834 standard fire curve. The charring depth of each timber beam was calculated by averaging the values at one-third and two-thirds along each cross section to give the charring rate of timber beams. It was found that the timber beam's charring rate reduces as the duration of fire exposure increases and the vertical charring rate is slightly higher than the horizontal one. The areas of beam sections reduce due to charring and the strength and stiffness of the pyrolysis layer near the charring edge decrease owing to the high-temperature. The average horizontal and vertical charring rates are 0.98 and 1.08 mm/min, respectively. To take into account the difference between the test furnace temperature curve and the ISO 834 stand- ard fire curve, some corrections were made for these data to yield the solution for charring rate. With the help of the finite element software ANSYS, the temperature distribution of the wood's cross-section was analyzed. The longer the exposure time is, the greater the effect of density will impose on the distribution of temperature, but the moisture content has no effect.展开更多
基金Supported by the National"Eleventh Five-Year"Key Scientific and Technological Support Program Project(2007BAK22B04)2008 Independent Task(SKLCRSM08B12)
文摘Studied the changes of heat physical parameters, gas concentration of O_2, CO,CH_4 and H_2, and temperature through full scale wood fire experiments in a tunnel and simulationby FLUNET, a kind of computational fluid dynamics software.The results showthat the wood fire experiment and simulation are both oxygen-enriched combustions,which show that the simulation results coincide with the experiment.The results also provethat it is difficult for oxygen-enriched combustion to cause secondary disasters.Somesuggestions were put forward to prevent the occurrence of secondary disasters effectively.
基金supported by the National Natural Science Foundation of China (Grant No. 51178115)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘To investigate the charring rate of timber beams exposed to three-side fire, a total of fifteen new and used Douglas-Fir timber beams in four groups exposed to three-side fire were experimentally studied, together with the finite element analyses of the temperature distribution in the beam section. The durations of fire exposure were 0 (on a test piece), 10, 15, 20 and 30 min, according to the ISO 834 standard fire curve. The charring depth of each timber beam was calculated by averaging the values at one-third and two-thirds along each cross section to give the charring rate of timber beams. It was found that the timber beam's charring rate reduces as the duration of fire exposure increases and the vertical charring rate is slightly higher than the horizontal one. The areas of beam sections reduce due to charring and the strength and stiffness of the pyrolysis layer near the charring edge decrease owing to the high-temperature. The average horizontal and vertical charring rates are 0.98 and 1.08 mm/min, respectively. To take into account the difference between the test furnace temperature curve and the ISO 834 stand- ard fire curve, some corrections were made for these data to yield the solution for charring rate. With the help of the finite element software ANSYS, the temperature distribution of the wood's cross-section was analyzed. The longer the exposure time is, the greater the effect of density will impose on the distribution of temperature, but the moisture content has no effect.
