Study On Rapid Sealing Explosion Venting Technology In Fire Area Of Coal Mine

After coal mine happened fire accidents,if the fire could not be directly extinguished,the fire area needed to be sealed,but the process can easily gave rise to gas exploration of secondary disasters.It caused by the high temperature and high pressure of flame front and shock waves and the toxic and harmful gases,and which cause a lot of casualties and damage facilities and equipment of coal mine.Aiming at the problems of the construction speed of sealing wall is slow,the sealing process time is long and the risk is high,it is necessary to design and develop a new rapid sealing explosion venting device.Based on explosion mechanics,combustion theory,thermochemical reaction kinetics and other basic theories.The method of combining theoretical analysis,numerical simulation and laboratory experiments is adopted to research on the variation law of gas explosion characteristics under the action of explosion venting door,proves its venting effect and performance,as this guide to design the rapid sealing explosion venting door of coal mine.The research results have important theoretical significance and practical application value for the rapid sealing of fire area and the explosion-resistant,flame-proof,and explosion venting of gas explosion.Experimental system of rapid sealing and explosion venting for gas explosion in fire area was developed and constructed.Research and development to design the experimental system of rapid sealing and explosion venting,it includes the Length 17.5m and large diameter(630mm)experimental pipeline of explosion system,gas distribution ignition system,control system and data acquisition system,it can completes the rapid sealing and explosion venting experimental for gas explosion in experimental tank.Explosion venting characteristics experiment of rapid sealing and explosion venting under the action of the explosion venting door in gas explosion pipeline have been studied.Experimental system of rapid sealing and explosion venting for gas explosion in fire area was used.Premixed gas explosion experiment in pipeline of sealing and explosion venting characteristics were been done,the influence law of the explosion pressure,the flame temperature and the flame propagation velocity under the condition of the empty pipe and the venting door were contrasted and researched,sealing and explosion venting effect of explosion venting door were analyzed.The experimental results show that the decay rate of pressure peak is 53.3%after explosive blast wave through the explosion venting door.At 210ms after the explosion,the explosion venting door relieves pressure and closes automatically,the closed region begins to appear negative pressure state and until 13.9h gradually return to positive pressure,it shows that the explosion venting door not only has explosion venting function but also has rapid sealing.Numerical simulation study on gas explosion rapid sealing explosion venting technology in fire area of coal mine.The study had set up the physical model of the pipeline gas explosion,the law of explosion pressure,flame temperature and flame speed were studied by mathematical model of gas explosion.The results of calculation model are compared with the results of experimental in this paper,and the simulation results are in good agreement with the experimental values,and which proved the reliability of the numerical models.Based on the pipeline characteristic experiment and numerical simulation,the influence of different concentrations of premixed gas and different explosion venting area ratio on gas explosion propagation law and explosion venting door sealing explosion venting were studied by mathematical model of gas explosion.Reasonable parameters of explosion venting door were studied,and rapid sealing explosion venting door was designed.The results have showed that with the increase of explosion venting area ratio,pressure peak decreases,velocity peak and temperature peak and velocity drop rate increase.A new type of rapid sealing explosion venting door in fire area is developed.The design of the explosion venting door can solve the main existing problems of explosion proof and explosion suppression active or passive at present.It makes the underground staff can be safe and effective to seal the fire area and the staff is not on the scene and provide new ideas for the research work of the new type of making close and venting device.