Experimental Study On Temperature Field And Smoke Flow Of Conveyor Belt Fire In Flat Tunnel

Using the large scale of the combustible material conveyor belt, the hidden danger of fire is larger, the accident is higher, and seriously threat the safety of the miners. In order to find out the law of fire spread and smoke movement, a small size belt fire platform was established. The combination of experiment and numerical simulation was used to analyze the heat release rate of conveyor belt. On the basis of this study, the influence of fire location and ventilation rate on the temperature field and smoke flow of conveyor belt was studied. The main conclusions of this paper are as follows:(1) Based on the small size belt conveyor fire experiment platform, when the ventilation rate is 0.4 m/s, the average heat release rate of belt conveyor was the largest, reaching 2.51 kW. The ventilation rate increases from 0 m/s to 0.4 m/s, and the average heat release rate of conveyor belt is increasing in turn. When the ventilation rate is more than 0.4 m/s, the average heat release rate begins to decline, and the average heat release rate is lower than that of the ventilation rate is 0 m/s.(2) Based on small size belt conveyor fire experiment platform, in loading mechanical ventilation(0.2 m/s, 0.4 m/s, 0.6 m/s, 0.8 m/s) and space tunnel airflow fast flow away, the tunnel appear obvious negative pressure, external oxygen enriched air is sucked into the burning region, the high temperature smoke leeward motion, the roadway under the direction of the wind appears high temperature region.(3) The location of fire source has a certain influence on the temperature of the entrance and exit of the tunnel, but it has little influence on the distribution of temperature field in the middle part of the tunnel.(4) Under the experimental and simulation results, it is concluded that: The location of fire source has a certain influence on the distribution and energy exchange of the high temperature smoke at the entrance and exit of the tunnel, but it has little influence on the temperature field and smoke at the middle position of the tunnel. Ventilation rate increases, the belt conveyor fire of high temperature smoke flow in the tunnel in the rate of spread increases, each measuring point of extreme temperature and S# measuring point smoke concentration appeared a certain degree of decline, but high temperature smoke spread rate increased significantly.(5) Tunnel fire location of belt conveyor fire temperature field and smoke spread has weak influence and ventilation condition of belt conveyor fire temperature field and smoke flow spread effect is very significant, further suggests that ventilation is the main factors that influence the spread of straight roadway belt conveyor fire development.