海底隧道电缆的防火性能化设计

Performance-based fire protection design of cable in subsea tunnel

厦门海底隧道东通道220kV高压电力电缆敷设于车行隧道服务隧道内,电缆防火设计比较了三种方案。超细干粉灭火系统一次灭火费用少,控制方式简单,但灭火后需清理粉尘,可能出现误动作,日常维护困难;无管网SDE气体灭火系统一次性投资少,灭火后无需清理,但一次灭火费用高,可能出现系统误动作,日常维护困难;最终采取的性能化设计方案为提高电缆截面面积,将电缆设置于无机不燃耐火电缆槽盒中,在空隙填充阻火包,每隔30m设置磷酸氨盐灭火器。性能化设计方案具有施工、维护简便,安全性能高的特点。

There are three projects of fire prevention of 220 kV cable in the Xiamen subsea tunnel east channel. The control is simple of ultrafine dry powder fire extinguishing system and it costs less in fire extinguishment, but the powder should be removed after extinguishment. The system may misact and the daily maintenance is difficult. Setting of SDE gas extinguishing system without piping costs less and needs no clean after extinguishment. It costs a lot to put out the fire and the system may misact. The daily maintenance is difficult. The performance-based fire protection design used finally set the cable in inorganic fire retardant trough and fill fire retardant packet at void. The section area of cable is bigger. There are ammonium phosphate fire extinguishers every 30 m. The construction and the maintenance are easy of performance-based fire protection design, and it＇s safer.