Numerical simulation study on duct smoke exhaust mode and induced smoke exhaust mode in underground garages

Using FDS software, analyses and compares the airflow velocity distribution, temperature distribution, CO concentration distribution, visibility and smoke layer height in the garage under the water spray coupling effect with duct smoke exhaust mode and induced smoke exhaust mode, and the influence on the sprinkler activation. The results show that each index of the garage fire condition controlled by the two kinds of smoke exhaust systems can meet the requirement of personnel evacuation. But the induced smoke exhaust mode is not as good as the traditional duct smoke exhaust mode on stability of smoke layer and smoke layer height control. The induced smoke exhaust mode is not suitable for the crowded places because of its bad effect on the downstream of fire source and the evacuation. Because of few people in the underground garage, suggests that the induced smoke exhaust mode can be taken instead of the duct smoke exhaust mode in order to improve the efficiency of the unit parking.