Simulation Of Fire Smoke Flow And Emergency Evacuation Of High Speed EMU Train

In recent years,China ’ s high-speed railway continues to speed up,the structure and equipment of high-speed EMU trains are constantly updated,which has brought great convenience to travel personnel.However,the high-speed operation of trains,the increase of electrification equipment and the renewal of interior materials have increased the potential fire hazards of trains to some extent.The driving safety of trains along the railway is an important part of railway transportation safety protection.Once a train fire occurs,it will cause disastrous harm.In the case of fire inside the high-speed train compartment,emergency escape window broken by personnel panic and window glass rupture caused by high temperature,the train will form a certain amount of vents,and the formation of opening fire will increase the harm of fire to people and various structures.In order to explore the smoke flow and temperature distribution in the carriage and tunnel under high-speed train fire,Pyrosim was used to establish a numerical calculation model for fire of a certain type of second-class compartment of my country’s Fuxing.Under the condition of closing the outer doors 3min after the fire,for the viaduct train fire,the influence of the ruptured states of the windows and different relative wind speeds on the smoke flow and temperature distribution of compartment fire was studied,and the safety of the train operation on viaduct under the fire was evaluated.For the railway tunnel train fire,the influence of different fire powers and different window rupture models were studied.The results show that: for the viaduct train fire,when the emergency escape windows is artificially smashed,whether the unilateral opening or the convection opening has no obvious effect on the overall temperature inside the passenger compartment.In the early stage of the fire,the fire mainly spreads to the ruptured side of the escape windows.As the relative wind speed increases,the temperature of compartment aisle decreases,the time of the smoke reaching the end door of the passenger compartment on both sides increases,but the thickening rate of the smoke layer increases.In the early stage of the fire,the increase of relative wind speed has more obvious effects on the cooling and smoke exhaust through the platforms on both sides,reducing the scope of the danger zone.The period before 50 s is the best time period for people to escape.Considering the personnel evacuation and the spread of fire,it is proposed that the safe operating speed of the train compartment after a fire is 40km/h.Under the same time when the outer door was closed after the fire,for the railway tunnel train fire,the smoke flow and open fire overflow in the carriage and tunnel under different fire power and different window rupture modes were studied.The results show that :for the railway tunnel train fires,under the same fire power,the more man-made broken windows,the faster the train reaches the maximum temperature,the earlier the side windows,near the fire breaks,and the earlier the smoke reaches the tunnel port;With the same fire power,the closer the broken window is to the near fire source,the faster the smoke spread in the tunnel.For low-power tunnel trains such as 4MW and8 MW,the maximum temperature at the top of the tunnel does not exceed 180℃,which has little effect on the wall structure of the tunnel.It is relatively safe to evacuation the tunnel rail surface.The personnel should be as far away from the body and move against the wall towards the nearest rescue evacuation channel.Based on the simulation analysis of each fire scene,the evacuation under typical working condition was simulated to determine the safety of evacuation,and the evacuation strategy was compared to obtain the better evacuation suggestions.The results show that both the guided evacuation plan and the free evacuation plan do not exceed the train’s limit escape time.Although the guided evacuation plan takes longer than the free evacuation plan,the evacuation efficiency is higher,and it is not easy to cause congestion on the evacuation path.reduces the possibility of a stampede accident.Based on the consideration of personnel evacuation,it is suggested that the occupants should accurately judge the fire situation and command evacuation according to certain guiding principles.Passengers should evacuate orderly under their command.It is suggested that the size of the corridor and the door should be appropriately relaxed.It is suggested that high-speed trains should be equipped with emergency escape ladders in the tool cabinets of each carriage passing through the platform or install electric emergency escape ladders under the plug door of each carriage.