Analysis of Early Warning Indicators for High Voltage Power Cable Tunnel Fire Based on Experimental Data

Currently, high voltage power cables have gradually entered cable tunnels, and fire prevention in cable tunnels is an important part of the safe and reliable operation of the entire power grid system. The paper established a simulation and measurement experimental platform for high voltage power cable tunnel fire smoke. Based on the typical working conditions of cable heating, ignition and combustion, combined with experimental data, the variation characteristics of CO concentration, CO
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concentration, smoke density, and temperature at each position of the ceiling under the closed state of both ends of the tunnel were analyzed. The analysis results indicate that the CO concentration and smoke density at the ceiling position can be used as the optimal landmark parameters for early fire warning, while CO
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concentration and temperature are less suitable. Under the conditions of setting the warning thresholds for CO concentration and smoke particle concentration to 10ppm and 0.05dB/m respectively, early fire warning can be achieved at all ceiling positions. The research results can provide guidance for the design of high voltage power cable tunnel fire warning systems and related warning standards.