| Mine fire is one of the key disasters in China’s coal mines,and the main one is coal spontaneous combustion.Coal spontaneous combustion will not only cause significant resource consumption and economic loss,but also directly endanger the life safety of underground employees.In order to reduce the waste of coal resources,ensure the safe production of the mine,and further develop the new technology of mine fire prevention and control to prevent coal spontaneous combustion,this paper proposes to take antioxidant as the inhibitor,screen the compounded foaming agent solution as the foam component,and form a stable inhibitor foam system under the action of nitrogen.Compared with ordinary foam,this foam system has significantly improved the stability of foam and its fire prevention and extinguishing performance.The research results of this paper are as follows:A new type of inhibitor foam was developed by compounding foaming agent and screening inhibitor.When foaming agent C and D are mixed at 2:3,foam has the best foaming ability;The optimal concentration of foam solution was 0.4% by stirring foaming method;Three kinds of antioxidants were selected as inhibitors to test their inhibition effect on coal combustion,and the parameters such as heat release rate,total heat release and effective combustion heat were compared and analyzed to determine the inhibitor component of foam inhibitor as inhibitor Y.By testing the influence of inhibitor Y on the foam performance of the foam,it is concluded that adding inhibitor Y can increase the foam volume of the foam solution,extend the half-life,and the mass concentration of inhibitor Y is 1%.The rheological properties and diffusion and accumulation properties of the inhibited foam were studied.The results show that the viscosity of the retarded foam system gradually decreases with the increase of the shear rate,showing a shear thinning characteristic;When the mass concentration of inhibitor or foaming ratio increases,the shear stress and apparent viscosity of the inhibited foam increase accordingly.When the concentration of inhibitor increases to a certain concentration or the foaming ratio is high,the growth rate of the apparent viscosity of the inhibited foam gradually decreases;Pseudoplastic fluid and yield pseudoplastic fluid model are used to fit the shear stress curve of the inhibited foam,and it is concluded that pseudoplastic fluid is more suitable for describing the rheological characteristics of the inhibited foam,and power rate model is used to characterize the rheological constitutive equation of the inhibited foam;Based on Fluent software,the diffusion and accumulation of inhibited foam in the goaf are simulated.When the working face dip angle is 5 °,the maximum accumulation of inhibited foam in the goaf is about 4.42 m,and the maximum total diffusion width of inhibited foam along the strike is about 34.98 m.The inhibitive property and fire-extinguishing and cooling performance of the foam were studied.The experimental results show that compared with other inhibitive materials,the inhibitive foam has excellent low-temperature inhibitive and fire extinguishing and cooling performance.At low temperature,the inhibited foam can prolong the time of intersection temperature,inhibit the release of index gas,and reduce the heat release during coal oxidation;The inhibition of foam in the oxidation heating process can inhibit the consumption of hydroxyl and aliphatic hydrocarbon functional groups,and delay the oxidation heating process.In high temperature environment,compared with ordinary foam and inhibitor,the inhibitor foam can effectively extinguish the coal pile on fire,cover the coal surface for a long time,quickly reduce the temperature of the coal pile,and achieve the purpose of rapid fire extinguishing and cooling.Figure 62 Table 13 References 80... |
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