Numerical Simulation Study On Fire Control And Personnel Evacuation Of High Speed Trains

With the continuous development of the social economy,there are more and more types of travel options that people choose.Due to its fast speed,high comfort,and large passenger capacity,China’s high-speed railway is regarded as the main mode of transportation by people.But one issue that cannot be ignored is its security.During train operation,due to the closed and narrow carriages,it is difficult to evacuate personnel in the event of a fire,which can easily lead to casualties.Therefore,it is necessary to study the control of high-speed train carriage fires.This paper takes the CRH5A Multiple unit single second-class carriage as the research object,constructs the FDS model,and uses PATHFINDER to evacuate people.Conduct research on optimizing the internal equipment and structural layout of the train without changing its basic overall structure.The main focus is to replace the original ordinary windows with emergency windows and explore the wind speed at the rear exhaust duct opening of the carriage.The research results indicate that:(1)The opening and closing of car doors and emergency windows have a certain impact on the smoke generated by fires.Without changing the original structural layout of the train,opening the train doors and breaking the four opposite emergency windows located at the ends of both sides of the carriage are more conducive to smoke emission.Optimizing the structural layout of the train,with the doors closed and the original four emergency windows open,replacing the three pairs of ordinary windows located at about one-third of the two ends of the carriage with emergency windows is more conducive to smoke emission.The time for this state to reach the critical danger value is 195 s.(2)The location of different ignition sources has a certain impact on the smoke inside the carriage.When the ignition source is located in the middle of the carriage,the time when the smoke reaches the critical danger value is later than when the ignition source is located in the front and rear of the carriage.(3)Without changing the other layout of the carriage,according to the "Technical Standards for Building Smoke Control and Exhaust Systems"(GB51251-2017),the wind speed at the exhaust outlet should not exceed 10m/s.The wind speeds at the original exhaust duct openings at the rear of the carriage were explored at 2,4,6,8,and 10m/s.The wind speed of the smoke exhaust outlet is 8m/s(with a smoke exhaust volume of 0.32m)~3/ s)The fire source is located in the middle of the carriage.When the original four emergency windows are opened and the doors are closed,the latest time for this state to reach the critical danger value is 150 seconds.(4)According to the evacuation of personnel inside the carriage,when the fire source is in the front of the carriage,the evacuation time is 293.3 seconds;When the fire source is in the middle of the carriage,the personnel need 144s;When the ignition source is at the rear of the carriage,the personnel need 323.8 seconds.When the fire source is in the middle of the carriage,the doors are closed in the early stage,and four original emergency windows are opened.It is proposed to add a pair of ordinary windows located in the middle of the carriage and replace them with emergency windows.The required safe evacuation time for personnel is ≤ the time to reach the critical danger value;When the fire source is in the middle of the carriage,the doors are closed in the early stage,and four original emergency windows are opened.When the exhaust air speed is 8m/s,the required safe evacuation time for personnel is ≤ the time to reach the critical danger value.