熔融硝盐高温分解爆炸事故后果严重度评价

为评价热处理用硝盐槽熔融硝盐高温分解爆炸事故机理和后果严重度，结合某企业铝合金件硝盐固溶热处理工艺进行研究。 利用压缩气体容器爆炸能量计算模型、超压准则和TNT当量法估算热处理用硝盐槽内熔融硝盐高温分解爆炸事故后果，得出35 000 kg熔融硝盐在高温分解转化率为50%时爆炸的TNT当量为1 257.6 kg，爆炸会造成半径53.97 m范围内的人员轻伤，该结果和利用政府推荐的危险指数法得出的外部防护距离为50 m较为接近。 以上分析计算表明:超温爆炸过程中，熔融硝盐在硝盐槽中超温分解快速产生大量气体，在硝盐槽上盖及上部硝盐的阻挡下不能及时排出，致使硝盐槽内气体压力瞬间升高，形成类似于压力容器的空间，发生物理爆炸并引发高温硝盐喷溅。

Accident consequence evaluation on molten nitrates pytolisis

To study the accident mechanism and consequence severity of pyrolysis explosion by the molten nitrate in the nitrate tank for the heat treatment, the research was carried out combined with the heat treatment process of the molten nitrate solid solution for the aluminum alloy parts in a certain enterprise. The accident consequence of pyrolysis explosion by the molten nitrate in the nitrate tank for the heat treatment was estimated by using the calculation model of explosion energy for the compressed gas vessel, the overpressure criterion and the TNT equivalent method. It showed that the TNT equivalent for the explosion of 35 000 kg molten nitrate was 1 257.6 kg when the pyrolysis conversion rate was 50%, and the explosion would cause the minor injuries of the personnel in the range with the radius of 53.97 m, which was relatively close to the external protection distance 50 m obtained by the risk index method recommended by the government. The results showed that in the process of overtemperature explosion, large amount of gas was produced rapidly by the overtemperature pyrolysis of molten nitrate in the nitrate tank, which could not be discharged in time by the blocking of the upper cover and the upper nitrate in the nitrate tank and caused the gas pressure in the nitrate tank increased instantaneously, so the space similar to the pressure vessel was formed, then the physical explosion occurred and induced the splash of high temperature nitrate.