| Popis: |
Oxygen enrichment at high altitudes indoors can be effective in meeting demand. However, the high oxygen environment inevitably brings about additional fire hazards, and the specific changes are still unclear. As pine wood is a common material in construction, this paper provides data support for fire protection for buildings in highland areas by studying the combustion characteristics of pine wood at different oxygen concentration (21.0%, 23.0%, 30.0%, 27.0%, 33.0%) under different atmospheric pressures (50.0 kPa, 60.0 kPa, 70.0 kPa). The results show the relations of mass loss rate and the oxygen concentration with different pressures: m∝PYO2,∞21.84 (m is the mass loss rate; P is the pressure; and Yo2 is the oxygen concentration). The relation of flame spread rate and the oxygen concentration with different pressures is also shown: Vf∝PYO24.51.2 (Vf is the flame spread rate). It was observed that the increase in pressure and oxygen concentration made the combustion reaction more complete, for burning time, flame area, flame propagation rate, MLR, flame temperature, and CO2 production increase, but CO shows an opposite trend. Oxygen enrichment will significantly increase the fire risk of pine wood within a low-pressure environment. |
