Numerical Simulation of Fire-induced Smoke in Train Compartment Based on Fire Dynamics Simulation

In order to examine the flow law of the fire-induced smoke in a train compartment, the study took the internal space of one compartment of the high-speed train CRH2A as a research object. Nine sets of working conditions were examined according to the states of the carriage doors, fire source power, and discharge velocity of the air curtain. The smoke flow law was numerically simulated under these different conditions using the fire dynamics simulation software. The smoke diffusion process, visibility within each area, and temperature distribution and tendency were calculated and analyzed for the internal fire. The results showed that when the doors were closed, the smoke temperature was relatively higher, the smoke layer descended more rapidly, and the visibility was lower than when the doors were open. In addition, a higher value for the fire power resulted in a higher value for the actual total heat releasing rate. Under the conditions that the fire source power was 0.2 MW and the doors were open, the best value for the outlet velocity of the air curtain was 5 m/s in consideration of the effectiveness of the preventive smoke and economic factors. These research results have specific theoretical and practical significances in relation to the guidelines for the efficient prevention and control of a train fire.