PVC热解特性研究

Research on Thermal Decomposition Characteristics of PVC

在电缆火灾的初期,外护套材料会热解产生特征气体,通过对这些特征气体的监测可以实现电缆火灾早期预警。由于PVC是最常用的电缆外护套材料,文章搭建了PVC热解实验平台,对PVC的热解气体使用GC-MS和气体检测管进行分析,研究PVC热解特性。通过实验发现:PVC热解会产生CO_(2)、C_(2)H_(6)、C_(2)H_(4)、C_(3)H_(8)、C_(3)H_(6)、C_(4)H_(10)、CH_(3)Cl、2-C_(4)H_(8)、C_(4)H_(6)、C_(5)H_(12)、C_(6)H_(6)和CO等十余种气体,其中CO、CH_(3)Cl和CO_(2)在PVC电缆火灾初期浓度变化最为明显,适合作为PVC电缆火灾早期特征气体。

In the early stage of cable fire,characteristic gases are generated from the pyrolysis of outer sheath materials.The early warning of cable fire can be realized by monitoring these characteristic gases.As PVC is the most commonly used material for cable sheath,the pyrolysis experiment of PVC was carried out.The pyrolysis gas of PVC was analyzed by gas chromatography-mass spectrometry(GC-MS)and gas detection tube,and the pyrolysis characteristics of PVC were studied.It was found that PVC cable would pyrolyze to produce more than ten kinds of gases,such as CO_(2),C_(2)H_(6),C_(2)H_(4),C_(3)H_(8),C_(3)H_(6),C_(4)H_(10),CH_(3)Cl,2-C_(4)H_(8),C_(4)H_(6),C_(5)H_(12),C_(6)H_(6)and CO.Among them,CO,CH_(3)Cl and CO_(2)have the most obvious concentration change in the initial stage of PVC cable fire,and are suitable for the early characteristic gases of PVC cable fire.