电缆隧道L型防火隔板的隔热效果分析与侧板高度设计

为兼顾电缆隧道中L型防火隔板的隔热效果和施工安装的便捷性，需确定不同工况下L型防火隔板所需最低高度。为此，利用FDS模拟软件，设置不同侧板高度，针对不同火源功率条件下L型防火隔板对不同电压等级电缆的保护效果进行模拟，分析安装隔板区域的温度变化和烟气扩散。结果表明：火源功率为400，600 kW时，电缆充分燃烧阶段至衰减末期，烟气蔓延速度分别比火源功率为200 kW时约快50%和66%；当110 kV电缆层间距为0.5 m，火源功率为200，400，600 kW时，L型防火隔板侧边最优高度分别为0.20，0.25，0.25 m；当10 kV电缆层间距为0.25 m时，三种火源功率下L型防火隔板侧边最优高度分别为0.100，0.125，0.125 m，隔板上方被保护电缆护套层温度均低于热解温度。研究成果可为不同工况下防火隔板侧板高度设计提供参考。

Heat insulation effect analysis and side panel height design of L-shaped fire baffle in cable tunnel

Abstract: In order to take into account the thermal insulation effect of the L-shaped fire barrier in the cable tunnel and the convenience of construction and installation, it is necessary to determine the minimum height required for the L-shaped fire barrier under different working conditions. For this reason, this paper adopts FDS simulation method to numerically simulate the protective effect of the L-shaped fire barriers with different side plate heights on the cables of different voltage levels under different fire source powers, and analyze the temperature changes and smoke in the area where the partitions are installed. The results show that when the fire source power is 400 kW and 600 kW, the smoke spreading speed is about 50% and 66% faster than when the fire source power is 200 kW from the full combustion stage of the cable to the end of attenuation; When the 110 kV cable layer spacing is 0.5 m, with the fire source power of 200, 400, 600 kW, the optimal heights of the sides of the L-type fire barrier are 0.20, 0.25, and 0.25 m respectively; When the distance between the 10 kV cable layers is 0.25 m, the optimal heights of the sides of the L-shaped fire barrier under the three power of the fire source are 0.100, 0.125, and 0.125 m, respectively, and the temperature of the sheath layer of the protected cable above the partition is lower than the pyrolysis temperature. This research result can provide a reference for the height design of the side panel of the fire barrier under different working conditions.