Experimental and Modeling Study of Atmospheric Pressure Effects on Ignition of Pine Wood at Different Altitudes

The pyrolysis land ignition characteristics of wood in different atmospheric pressure are investigated experimentally and theoretically. A set of contrast experiments is carried Out to study the effects of atmospheric pressure oil the ignition characteristics of pine in the Tibetan plateau and Hefei, respectively. The experimental location pressure is 0.66 atm in the Tibetan plateau and 1.0 atm in Hefei. An extended model considering the atmospheric pressure and unsteady gas-phase processes is developed to predict the pyrolysis of wood. A comparison to experimental data shows that the predicted change trend of the mass loss rate using the model is relatively in good agreement with experiments. The results indicate that a lower atmospheric pressure Call result in higher mass loss rates under the same external hem flux and the ignition time of wood in the Tibetan plateau IS much earlier than that ill Hefei. Further analysis is directed to assess a new relationship between the pressure and critical heat flux of flaming ignition, which confirms that the atmospheric Pressure Plays a vital role in pyrolysis and ignition of wood.