化工企业雷电灾害风险评估与应用

以沧州某化工项目为例,通过现场勘测和图纸分析,评估化工生产装置雷电防护现状。利用闪电定位监测资料统计分析项目区的雷电灾害特征,可能的影响、雷电危害分析等;参考IEC62305-2评估方法,有针对性的对项目进行雷电灾害风险评估,提出了风险控制措施和建议。结果表明:项目所在地雷击大地密度较大,雷电流幅值主要集中在20~60kA。雷电造成的人身伤害风险主要是由于雷电击中建筑物导致物理损害引起的,约占70.50%。其次是雷电击中相关管道和线路引起,约占29.37%,主要是电力系统。按照估算,各建筑基本达到防雷要求。对于区域内所有建筑物,雷击人身伤害风险都小于国际上通用的风险允许值,但原设计方案中缺少电压保护水平设计。对雷击建筑物、设施、管道和线路可能造成的自动化设备中断、误动作等导致的有毒物质泄漏、易燃事故发生等风险还需进一步加强风险控制措施。指出设计院将易燃等区域设计成第三类防雷建筑物以及自动化控制系统系统是雷电风险的主要来源。

Implementation of Lightning Risk Assessment in Chemical Plant

Taking a Cangzhou chemical project as an example,based on the site investigation and drawing analysis,a lightning hazard assessment is conducted on the current situation of lightning protection for chemical processing devices.The statistical analysis of lightning disaster features,possible influences, lightning hazard analysis,etc.are made by using the lightning data in this project.Referring to the evaluation methods in IEC62305-2,targeting at the project for lightning risk assessment,the risk management measures and suggestions are put forward.The results show that the lightning density is large relatively,and the lightning current amplitude is mainly from 20to 60kA.The personal injury risk caused by lightning is mainly due to physical damage caused by flashes to structure,making up about 70.50%.The second is the risk caused by flashes happened in the related pipes and lines,making up about 29.37%,but mainly in the power system.According to the formal estimation,each structure can meet the basic lightning protection requirements.As for the buildings in this region,the personal injury risk caused by lightning is less than the universally tolerable risk home and abroad.But the original design is short of voltage protection level design.For automation equipment interruption caused by lightning strike to buildings,facilities,pipes and lines,as well as misoperations,may lead to the leakage of toxic substances and flammable accidents,it is still necessary to take further risk control measures.It is important to point out that flammable areas are considered as the third type of lightning protection in the designs of design institutes,as well as the automation control system,is the main sources of lightning risk.