Analysis of Abnormal Detection Data of Fire Accident in Power Cable Tunnel and Field Test Study on Characteristic Parameters of Tunnel Fire

With the continuous expansion of urban cable scale and the increase in service time, the fire accident risk of cable tunnels also increases. Defects in the configuration of fire prevention measures lead to many fire accidents and seriously affect the reliability of power supply. First, the detection data of a typical tunnel fire accident are analyzed in this study. The results show that the main problems are the unreasonable installation position of fire extinguishers, the lack of fire prevention measures between intermediate joints, and the insufficient fire prevention performance of interlayer fire barriers. Then, the field test of cable tunnel fire is carried out in a cable tunnel to be put into operation. The test data show that the high-temperature area is mainly concentrated on the top of the tunnel, and the insufficient suspension height of the fire extinguisher will affect the trigger time. The energy of a short circuit accident is large, the cable burns and spreads rapidly, and the delayed triggering may lead to large fire to extinguish effectively. Comparing the simulation and test results of abnormal characteristic parameters in fire, the temperature error is less than 4%. The fire power development curve is obtained through simulation, and the burner power is set to test the fire prevention and extinguishing devices. Finally, the optimal configuration scheme of the fire anomaly data detection equipment and fire-extinguishing products is proposed. The temperature drop rate increases by 135%.