聚苯乙烯外墙保温系统火灾风险影响因素分析

为了研究聚苯乙烯外墙保温系统火灾风险的问题，对比了3种火灾测试方法，分别是基于ISO 5660的小尺寸锥形量热计实验方法、基于ISO 9705的大尺寸实验方法和基于BS 8414的全尺寸实验方法。讨论了3种方法评测外墙保温系统火灾风险的适用性，进一步在比较分析热释放速率、临界热流强度、火蔓延情况、火灾行为以及实验后样品完整性等参数的基础上，得到了影响聚苯乙烯外墙保温系统火灾风险的关键因素。结果表明:虽然空腔的形成在此类系统火灾中不可避免，但系统保护层的严密性和完整性决定了空腔火蔓延的危险性以及聚苯乙烯在系统内的融化流动及燃烧特性。针对聚苯乙烯外墙保温系统火灾风险影响因素，进一步给出了此类系统的防火措施。

Analysis on influencing factors of fire risk in polystyrene exterior wall insulation system

Aiming at the fire risk of polystyrene exterior wall insulation system, three kinds of fire test methods were compared, including the small scale cone calorimeter test method based on ISO 5660, the large scale test method based on ISO 9705 and the full scale test method based on BS 8414. The applicability of the three methods in evaluating the fire risk of the polystyrene exterior wall insulation system was discussed. Based on the analysis of the parameters such as the heat release rate, the critical heat flux, the fire spread, the fire behavior and the sample integrity after the tests, the key factors that affect the fire risk of the polystyrene exterior wall insulation system were obtained. The results showed that although the formation of cavities is unavoidable in the fire of such systems, the tightness and completeness of the protective layer of the system determine the risk of fire spread in the cavity as well as the melt flow and combustion characteristics of polystyrene in the system. According to the factors that in-fluence the fire risk of polystyrene exterior wall insulation system, the fire protection measures of such systems were given.