Study On Action Law Of Environmental Factors To Fire Zone Gas Entrainment And Disaster Induced Mechanism

The technique of sealing fire zone is a common method of fire control. However, sometimes, this method probably may induce the possibility of gas explosion. The dissertation, first of all, analyzes the law of gas emission and accumulation state of gas in sealed zone. According to the mechanism of gas transportation and floating effect of gas, the dissertation has concluded the law of distribution as stratified way and the factors that influenced these. Considering the factor, which is the fluctuation of atmospheric pressure, is a noteworthy one that influenced the way of gas emission and gas transportation in fire zone, so the dissertation has studied the law of fluctuation of atmospheric pressure and proposed a new method which is the tech of Graph K-line using in the area of stock market-analysis. By the practical data collected in HeGang and TangShan, the data shows that the pressure travels as fast as voice-speed under ground and declines as the frequency of change of fluctuation decreasing, shows that the amplitude declines in a relative short range and the amount of gas emission increases as pressure declining. The dissertation established the mathematic model of which the cycle of pressure change. By this the dissertation amends the equation of flow-leakage of sealed wall. By analyzing the effect of law of pressure change to the way of gas transportation in fire zone, also considering the condition which induces the gas explosion, the dissertation analyses the possibility of gas explosion while injecting the inert gas. By establishing 2-dimension physical model of accident tunnel and mathematic model of fire flow and using of CFD, the dissertation stimulated the process of gas explosion during the injection of inert gas. The result of the research work did in the dissertation has supplied a important guide to the future work.