| Popis: |
In order to study the influence of different ventilation times on the fire of cable roadway in coal mine and provide reference for fire prevention and control of cable roadway in industrial and mining areas, a full-scale model of a cable roadway was established by FDS fire simulation software.Four ventilation conditions of 0, 2, 4 and 6 ventilation times per hour were simulated.The low velocity N-S equation driven by heat was solved by numerical method, and the smoke distribution, air concentration distribution and roof temperature change of fire source were obtained under the four working conditions.The relationship between the farthest ventilation distance and ventilation frequency was determined by analyzing the simulation data.The minimum smoke diffusion distance on the upwind side of the fire source was calculated to be 50.8 m.The simulation results show that: on the upwind side of the fire source, when the wind speed is less than 1.70 m/s, the time when the smoke reaches the farthest diffusion distance increases with the increase of wind speed; when the wind speed is greater than 1.70 m/s, the time when the flue gas reaches the farthest diffusion distance decreases with the increase of wind speed; the upwind side of the fire source is located at the upper part of the fire source, and the high temperature flue gas cannot diffuse and accumulate continuously, while the lower part has less smoke, which can not block the effect of wind flow.The results show that the air content difference between the upper and lower parts is more obvious when it is carried to the downwind side by the air flow, while in the downwind side of the fire source, the air flow is consistent with the smoke diffusion direction, and the air flow accelerates the smoke diffusion, making the air content in the upper and lower parts of the downwind side at a more uniform level; the ventilation frequency has no obvious effect on the time of reaching the stable temperature of the fire source ceiling, but has a certain impact on its temperature. |
