Numerical Simulation Of Fire Smoke Movement In The Bus Carriage

Bus fire accidents all over the country in recent years is a reminder on bus travel safety. The bus because of its personnel mobility, capacity, more space, the closed traffic environment is complex and changeable. Once fire accident fast burning speed, large fire hazard, susceptible to flashover, evacuation difficult, difficult to save, cause serious casualties and property losses and adverse social impact Therefore, this paper first investigates the theoretical research at home and abroad for a bus fire, including bus fire prevention design specification, full scale fire experiment study and computer numerical.According to the theoretical research achievements and the deficiencies, in considering the test cost conditions, this paper adopts a model of numerical simulation methods to analyze the bus compartment fire smoke movement law. And using Pyrosim, FDS as the bus caught fire location, speed, windows and doors opening and closing, the system launches the research effect of air conditioning system of the bus fire compartment.Under the condition of natural ventilation for the spring and autumn season, bus compartment fires set up27working condition. Analysis of simulation results:In windows and doors opening fire heat release rate reached the maximum, the fire located in the middle of the car reaches flashover first, unable to form stable hot flue gas layer.30s10m visibility quickly dropped to below2.4m which is not conducive to escape. Open fire area bigger, compartment combustion more fully, the heat release more. Position of window and door openings the temperature rises the fastest The vehicle speed is faster, the greater the effect of the external air flow disturbed by the smoke layer in carriage, stratification is not obvious.Under the condition of air condition and refrigeration system for the summer season, bus compartment fires set up2working condition. Analysis of simulation results:The maximum heat release rate reached29MW. Early bus compartment fire, air conditioning refrigeration system can control the temperature of the parts except fire under60℃. After the fire flashover, air conditioning refrigeration system has played an important role in fueling the fire.Under the condition of heating and ventilation system for the winter season, bus compartment fires set up2working condition. Analysis of simulation results:The maximum heat release rate reached12MW. Heating and ventilation system speed up the mass burning rate, facilitated the generation of compartment fire smoke.The research process and conclusions can provide help for the bus fire safety design, preventing fire accidents and fire accident investigation.