夹层电缆引发火灾的实验研究

模拟现代建筑夹层中贮藏大量未加金属导管防护的电线电缆所引发的火灾效应.在一个全尺寸燃烧套房模型中进行了起火室和顶棚夹层空间电缆火灾的实验研究,并采用大涡模拟的方法对实验中烟气速度场进行了数值模拟.结果表明,加明火源可以加强电缆的火灾功率;通风状况对夹层电缆火灾的温度场、烟气遮光度和火灾功率有明显影响.电缆燃烧产物中主要毒性气体为CO.电缆在夹层燃烧时,CO和CO2浓度均高于目标室和起火室中的浓度.而夹层毒气最为集中,其CO浓度远远超出OSHA和IDLH标准.电缆在夹层燃烧时发生火灾的危险性较大.

AN EXPERIMENTAL AND SIMULATION STUDY ON PLENUM CABLE FIRE

In order to simulate the fire of the cables in plenum, the fire tests on plenum cables were carried out in the burn room and plenum structure of a typical full-scale combustion flatlet model in the present paper. The typical full-scale combustion flatlet model contains another chamber defined as target room. The numerical simulation model named LES (large eddy simulation) is used to simulate characters of the fire scenario, such as temperature field and velocity field. The results show that the external fire source imposes fire behavior of cables evidently. The fire behavior and characteristics such as temperature field and distribution of obscuration are influenced by the ventilation situation. The main component of combustion toxicity is CO. Large quantities of smoke particles and CO are generated during the fire. They propagate through vent into target room, causing obvious reduction in visibility and a high toxicity of CO that endangers life.