一起起重机爆炸事故的技术分析与鉴定

Technical Analysis and Identification of Cause of a Crane Explosion Accident

为鉴定某钢"5·14"起重机箱梁爆炸事故,采用故障树分析(FTA)、试验和计算机数值模拟方法进行研究。首先,根据FTA,确定事故为箱梁内部爆炸性气体经点火源点燃而引起的化学爆炸。其次,对爆炸残留物进行试验分析,确定挥发性成分主要为二甲苯和长链烷烃;通过焊接试验,发现在常规焊接功率下,焊缝背面的最高温度很容易达到涂料燃点。最后,使用非线性动力分析软件AUTODYN-3D对箱梁内二甲苯爆炸进行数值模拟,计算事故的爆炸物的量。分析结果表明,事故是箱梁内部涂料挥发物由焊接点燃产生的爆炸。案例说明,在密闭性结构设备的涂装工艺中,残余涂料混入设备会成为安全隐患,在特种设备安全性检测中,应加强设备内部异物检测。

To identify cause of an explosion accident taking place on 14th May ,2012, in a certain steel company crane box beam, this paper analyzes a variety of reasons which may cause this accident with the methods of fault tree analysis, mathematical calculations, experimental analysis, and computer numerical simulation. Firstly, According to the fault tree analysis, we confirm that this accident is caused by a chemi- cal explosion： the explosive gas within the box beam was ignited. Secondly, based on experimental analysis of explosive residues, xylene and long-chain alkanes are found to be the main volatile components. Through welding experiments of normal power, it is proved that the highest temperature in back of weld could reach the burning point of paint easily. Thirdly, through welding experiments we find that the maximum tempera- ture of the back of weld can easily reach ignition temperature of the coating. Lastly, in order to calculate the explosive equivalent of the accident, we used the nonlinear dynamic analysis software AUTODYN-3D to make a numerical simulation of the xylene explosion within the box beam. And result shows that cause for this accident is from coating volatiles in box beam： they were ignited and exploded by welding.