Analysis of Fire Spread in High Voltage Cable Trench under Different Cable Laying Modes

With the continuous development of the power system, high voltage cable channel is widely used in urban construction, and becomes an indispensable part of power grid construction. However, in recent years, frequent cable fire accidents have seriously affected the safe operation of power grid, resulting in huge economic losses and even casualties. The proper layered laying of cable trench can play an important role in restraining fire spread and reducing the risk of cable burning. Based on the fire simulation software, this paper establishes the fire simulation model of underground high-voltage cable trench in substation, analyzes the change of temperature field and gas distribution in high-voltage cable trench by simulating the fire spread trend of two common cable laying modes, and draws the following conclusions: four layer cable laying mode is better than five layer cable laying mode, and four layer cable laying mode is better after the fire The method can effectively slow down the spread of fire, lower toxic gas concentration and better temperature field stability. At the same time, the temperature field and the distribution of toxic gas concentration are also found to be stratified. These conclusions are of great significance to reduce the loss of cable fire and to ensure the safety of fire fighters after the disaster.