氨分解装置中液氨储罐火灾爆炸危险性分析

Analysis on fire and explosion hazard of liquid ammonia tank in ammonia decomposition equipment

以某金属处理企业氨分解装置中液氨储罐罐区为例,对液氨泄漏后火灾爆炸事故及其伤害范围进行了研究,用池火、蒸气云爆炸和沸腾液体扩展蒸气爆炸模型进行计算分析,给出火灾、爆炸事故的人员伤害和财产损失范围。结果表明:围堤堤内池火或罐内池火时,罐区建构筑物内的汽化器、管道等设备会因直接过火或热辐射导致损坏,建筑内人员死亡,但难以波及罐区之外;蒸气云爆炸产生相当于1192.72kgTNT爆炸的当量,爆炸的后果严重,应重点防范,防范的重点为液氨泄漏、点火源;沸腾液体扩展蒸气爆炸的火球半径56.1m,持续时间8.7s,死亡半径27.2m,其源于储罐受热或系统突然失效,液体瞬时泄漏汽化并遇点火源而发生,具有突发性且后果严重,企业应高度重视并严格储罐及系统的定期检验与校验、密切关注系统的有效运行。

The liquid ammonia tank area in ammonia decomposition equipment of a metal processing enterprise was taken as research object to evaluate the hazard and damage area of fire and explosion accident .The scopes of inju-ries and property loss were calculated through pool fire model , vapor cloud model and boiling liquid expanding va-por explosion model （BLEVE）.The study result showed that carburetors , pipes and other equipments in tank area were damaged by hot flame and heat radiation in pool fires inside tank or fire dike , and the pool fire also caused casualties , but without outside impact of the tank area .The consequences of vapor cloud explosion were serious which produced the blast correspond to 1192 .72 kg of TNT.So it should be emphasized , and the prevention focus was liquid ammonia leakage and ignition source .The accident of BLEVE was a kind of unexpected physical explo-sion with a serious destructive force caused by heat radiation or system failure .The fireball radius caused by BLEVE was 56.1 m, the duration of explosion was 8.7 s, and the death radius was 27.2 m.So, the enterprises should attach great importance to effective operation of the system and carry out regular inspection and calibration oftank and system strictly .