Abstract:

A dynamic assessment approach for the consequences of H₂S-containing natural gas leakage accident is proposed, the temporal-spatial variation of released gas and emergency evacuation are both considered. The proposed approach is applied to a hypothetical accident scenario concerning H₂S-containing natural gas leakage on an offshore platform. A time-varying leakage profile is adopted considering the interference of emergency shutdown system (ESD) and blowdown system. An emergency evacuation time model is established considering the time sequence of emergency evacuation. In addition, the results obtained with the proposed approach are compared with that obtained with static assessment approach and semi-dynamic assessment approach. The inhalation dose of H₂S based on the static assessment method, semi-dynamic assessment method, and dynamic assessment method are 1.062×10⁵,7.230×10⁴ and 6.020×10⁴, while the corresponding mortality rates are 5.396×10^-2,2.848×10^-3 and 4.571×10^-4. The comparison results show that the proposed dynamic evaluation method more carefully considers the dynamic factors in the accident scene, which can effectively improve the accuracy of accident consequence prediction.

Key words: dynamic leakage, emergency evacuation, dynamic assessment, offshore platform, H₂S, computational fluid dynamics

摘要：

综合考虑受灾人员的应急疏散行为与泄漏气体积聚状态的时空变化，结合剂量响应模型提出海洋平台硫化氢泄漏中毒后果动态评估方法。应用所提出的方法对假想的海洋平台硫化氢泄漏事故后果进行评估，事故场景中考虑紧急关断系统（ESD）与放空系统对泄漏速率的影响，结合应急响应时序建立应急撤离时间模型。将基于动态评估方法得出的结果与基于静态评估方法、半动态评估方法得出的结果进行对比。基于静态评估方法、半动态评估方法与动态评估方法所得作业人员硫化氢吸入剂量分别为1.062×10⁵、7.230×10⁴和6.020×10⁴，对应的死亡率分别为5.396×10^-2、2.848×10^-3和4.571×10^-4。对比结果表明所提出的动态评估方法更细致地考虑了事故场景中的动态因素，能有效提高事故后果预测的准确度。。

关键词: 动态泄漏, 应急疏散, 动态评估, 海洋平台, 硫化氢, 计算流体力学