某核电厂蓄电池间通风系统防火响应分析与改进

Analysis and Improvement of Fire Response of Battery Rooms Ventilation System in a Nuclear Power Plant

蓄电池间通风系统属于电缆层通风系统(DVE)的子项,主要功能是为蓄电池间提供通风,保证换气条件(12V/h),以维持设备正常运行的环境温度,系统的送风量略小于排风量,保证室内有微小的负压,防止氢气积聚和外逸。根据系统设计,特殊瞬态运行:如果一个房间失火,关闭防火阀隔离该房间,其相应的通风系统是否停运,视具体情况而定。且蓄电池间的风机无自动联锁逻辑,需在380V低压配电盘上手动启动和停运。执行4SFZ蓄电池间所在防火分区试验时,如果模拟蓄电池间发生火灾,根据系统设计,相关防火阀自动关闭,但通风系统是否停运的判断标准并未明确,并且以现有通风管路,无论是否停运系统,均不利于灭火控制,此时的响应策略会导致风机损坏、含酸烟气扩散以及火灾蔓延。根据核电厂防火导则,修改蓄电池间通风系统布置,更新消防行动卡,将火灾对电厂安全重要功能的影响降至最低。

The ventilation system of the battery room belongs to the subitem of the cable floor ventilation system(DVE).Its main function is to provide ventilation for the battery room and ensure the ventilation conditions(12V/h)to maintain the ambient temperature for equipment proper operation.The supply air volume of the system is slightly less than the exhaust air volume,ensuring that there is a small negative pressure in the room and preventing hydrogen accumulation and escape.Depending on the system design,special transient operation:If a room is on fire,turn off the fire dampers to isolate the room,and whether its corresponding DVE is out of service depending on the circumstances.And the fan in the battery room has no automatic interlocking logic,which needs to be manually started and shut down on the 380V low-voltage switchboard.In the implementation of the 4SFZ battery room where the fire partition test is conducted,if the simulated battery room is on fire,according to the system design,the relevant fire valve is automatically closed,but the judgment criteria whethere the ventilation system is shut down is not clear.And with the exsiting ventilation pipeline,whether the system is shut down or not,it is not conducive to fire control,and the response strategy at this time will lead to damage to the fan,the spread of the acid gas and the spread of fire.According to the guide of fire protection for nuclear power plants,the ventilation system arrangement in the battery room is modified,and the fire action card is updated to minimize the impact of fire on the important functions of power plant safety.