موضوعات
عنوان مقاله English
نویسندگان English
The issue of fire safety in tunnels is very essential because the closure tunnels increase consequences of accidents significantly. Therefore, it is necessary to control fire development and smoke propagation with appropriate measures when fire occur. The ventilation system is used to control smoke propagation and the suppression system is used to prevent fire spread in tunnel. In the present study, fire in the tunnel with operating ventilation and suppression systems are simulated using an open source fire dynamic simulator (FDS). The results show that increase water flow rate leads to increase cooling effect of suppression system, also, increasing the water flow rate from 320 to 1280 liters per minute lead to increase the reduction of radiation flux at the downstream of fire from 40% to more than 75%. With the activation of suppression system with a median diameter of 100 and 1000 micrometers, the temperature difference with the environment decreases by about 70% and 34%, respectively. In the case of downstream area, with decrease in size of droplet diameter from 1000 to 100 micrometers, the radiation attenuation increases from 58% to 93%. Air flow leads to transport the droplets to downstream and increase the air flow rate leads to decrease radiation attenuation of suppression system for upstream area. The relative position of activated sprinklers affect the cooling and radiation attenuation ability of system. The suppression system by reducing the smoke temperature enables the ventilation system to resist the smoke backlayering with a lower velocity than the critical ventilation velocity.
کلیدواژهها English
