The Research On Law Of Smoke Flow In Diagonal Flow Network During Mine Fire Period

Mine fire is one of the top five disasters of coal mines, which will not onlyburn machinery equipment and coal resources, but also release the toxic andhazardous gases to endanger the lives of miners. The hot smoke can lead toconfusion of the air of mine ventilation system and cause more damage. So theresearch on law of smoke flow in diagonal flow network during mine fireperiod has important theoretical and practical significance on judge theromantic state, provide the basis for mine ventilation and fire prevention, andreduce the casualties caused by fire.In the paper, the research on law of smoke flow in diagonal flow networkwas based on theoretical research, experiment simulation and numericalsimulation.(1) Through field research of Huhewusu, designing and making the firesimulation experimental system in diagonal wind network as1:20based onsimilar theory and related criterion. The temperatures of wind on differentpoints during different periods were testing by experimental system andsimulated by FLUENT, the results showed that:①the maximum temperature error was3.9℃and the average error rate was9.3%, there were similar resultsand less errors between experimentally values and calculated value. So theformula of wind temperature on fire area and downwind tunnel was rational;②it can be known that the law of wind temperatures which became smallerwith the increase of the distance of fire location through the simulation.(2) Analyzed the gradient of wind temperatures during combustionstability according to the experimental determination and the results showedthat:①the gradient of wind temperatures reduced and to a lesser extent withthe change over time;②the gradient of wind temperatures reduced and to alarge extent which highest at84.3%while the same time.(3) Determined the values of the dynamic pressure of the differentmeasuring points, also calculated the values of the flow speed and air volumeby experiment. The results showed that: While the fire was on main transportcrossheading, air volume decreased in main transport crossheading and thecontact roadway which was far from the fire zone, at the same time, air volumein auxiliary transport crossheading and contact roadway which near the firezone was increased. Tunnel air volume decreased can easily lead to the accumulation of gas and other issues, and it may cause gas and coal dustexplosion. Meanwhile, the reduction of air volume leaded to the increase onconcentration of toxic or harmful gases, and the situation would affect therescue operation very much.(4) According to the changes in the amount of wind, it can be known:From the development and stable to the decay phase, the air volume wasdivided into two types in each branch, one reduced to the minimum valuefirstly and then gradually increased to normal; the other one increased to themaximum value firstly and then gradually decreased to normal.(5) The calculation method of air volume correction was proposed basedon the formation mechanism of resistance of fire zone and iterative algorithmof Scott-Hinsley. The method was verified though experiments and the resultsshowed that:①the formula has a better convergence, the correction will beless than0.01m3/s while the number of iterations were4times;②themaximum error was8.26%between theoretical and experimental values,meeting the engineering calculations required accuracy.