摘要
三相泡沫防灭火技术由于缺乏对其流动特性的研究,导致三相泡沫的应用工艺设计缺乏理论支持,对其在采空区中的防灭火作用也认识不足,为此,论文从研究三相泡沫基本流变特征入手,重点对三相泡沫在采空区的流动特性进行了较系统的研究。
The technology of Three-phase foam for mine fire fighting is lacking of research on the characteristic of three-phase foam＇s flow behaviors in mine goaf,so the application process design has always been lacking of theoretical support,the role of three-phase foam for fire fighting hasn＇t been absolutely recognized,In order to change this situation,foam flow behaviors in mine goaf was studied systematically in the paper.
In the paper,in order to obtain the viscidity characteristic,the rheological property of three-phase foam was studied.For the three-phase foam,the relationship between shear stress and shear rate was tested,the optimal rheological model was selected by the grey correlation analysis,and the constitutive equation was constructed which point out that the three-phase foam belong to the kind of yield pseudoplastic fluid.And then the result of the starting pressure gradient computed show that the leaking air force can＇t drive the three-phase foam.Finally put forward that the three-phase foam an interdict the leaking air and reduce the emission of hazardous gas in goaf.
In order to provide experimental fundamentals for theoretical study on seepage characteristics of three-phase foam,the osmosis device and the experimental measurement system were designed and constructed,and the experiment about the seepage characteristics of three-phase foam was completed.The pressure drop and flow during the seepage of three-phase foam was measured to analyze the resistance seepage characteristics of three-phase foam.The results show that the three-phase foam is characterized by shear thinning in low speed seepage;the main factors to the seepage resistance of three-phase foam are concentration of slurry and permeability of porous media,while the foaming multiple has little influence.The consistence between the results of the experiment and the numerical computation on the seepage experiment of three-phase foam based on the apparent viscosity from constitutional equation is found,and so it is testified that the apparent viscosity of three-phase foam which is derived from constitutional equation can be applied in the seepage calculation.
On the basis of the experimental study and theoretical analysis,seepage manner of three-phase foam in the gob was established,and three dimensional unsteady mathematical model of three-phase foam which seeps in the gob was established by the use of theory of multiphase flow and seepage flow.In order to verify the mathematical model,experimental and numerical simulation study on the flow characteristics of three-phase foam were carried out in the control of large area gob fire of small coal pits in surface mine,and characteristics of three-phase foam such as stack height and diffusion distance,etc were inspected on the spot,and the simulation results was coincident with the conclusions which was obtained by field observations.
Taken into account of the difficulty to observe the flow characteristics of three-phase foam in the gob hidden space,CFD simulation technology was drawn into the study on the flow characteristics of three-phase foam in the gob and numerical simulation method was raised to study the flow characteristics of three-phase foam.The flow characteristics of three-phase foam in fully mechanized caving face were studied when it poured by embedded pipe in upper crossheading.The results shows that stacking height and diffusion width of three-phase foam can each reach to 3.62 m and 36.9 m,and stacking height and diffusion width are notably affected by the face＇s dip angle and perfusion flow.Stacking height and diffusion width of three-phase foam are increased with the increase of perfusion flow,while the diffusion width of three-phase foam is greatly decreased with the increase of face angle.Relation curves of stacking height and diffusion width along with flow rate and face angle were drawn through a great deal of simulation study.
Under the guidance of the results of experimental and theoretical research,design method of application process for three-phase foam was established,and perfusion technology of three-phase foam in coal mine was been optimal designed and applied,which solve the fire prevention in large-scale fully mechanized caving face gob,large scale coal spontaneous combustion fire in surface gob and concealed fire at the near gob eare in fully mechanized caving face,and preferable fire prevention effect was achieved as well as the full play of three-phase foam in fire extinguishing efficiency.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2011年第2期355-356,共2页
Journal of China Coal Society
基金
国家自然科学专项基金资助项目(50927403)
江苏省创新学者攀登项目(BK2009004)
煤炭资源与安全开采国家重点实验室自主课题基金资助项目(SKLCRSM08x06)
关键词
矿井防灭火
三相泡沫
采空区
流动特性
优化设计
mine fire fighting
three-phase foam
mine goaf
flow characteristics
optimization design
