变电站电缆沟火灾探测试验与数值仿真研究

Research on fire detection experiment andnumerical simulation of cable trench insubstation

为探讨火灾探测器灵敏度对电缆沟火灾响应的影响程度,验证火灾监控系统的准确性,应用点式温度探测器、点式烟雾探测器、电缆式感温探测器和吸入式烟雾探测器4种火灾探测器,在标准变电站电缆沟防火分区内进行了全尺寸电缆火灾试验,测试不同灵敏度火灾探测器的火灾报警序列。根据电缆沟的实际尺寸,利用FDS搭建模拟明火和阴燃两种不同火灾场景,对不同灵敏度火灾探测器的温度场、有毒气体质量浓度和火灾报警顺序进行了分析和讨论。试验结果表明,在变电站电缆沟火探测中,电缆式感温探测器、吸入式烟雾探测器、点式感烟探测器火灾平均响应时间分别为41.2,111.4,331.8s;吸入式感烟探测器的灵敏度对探测结果影响较大,其火灾报警响应时间比电缆型线性温度探测器约延迟50%。

In order to explore the influence of the sensitivity of the fire detector on the fire response of the cable trench and to verify the accuracy of the fire monitoring system,four types of fires:point temperature detectors,point smoke detectors,cable temperature detectors and suction smoke detectors were ap-plied.A full-scale cable fire test was carried out in the standard substation cable trench fire compartment to test the fire alarm sequence of fire detectors with different sensitivities.Finally,according to the actual size of the cable trench,the FDS was used to build a numerical simulation model to simulate two dif-ferent fire scenarios of open flame and smoldering,and the tem-perature field,toxic gas mass concentration and fire alarm se-quence of fire detectors with different sensitivities are analyzed.The experimental results show that the average fire response time of cable temperature detectors,suction smoke detectors and point smoke detectors in substation cable trench fire detec-tion are 41.2,111.4 and 331.8 s respectively.The sensitivity of the detector has a great influence on the detection result,and its fire alarm response time is about 50%delayed compared with the cable-type linear temperature detector.