Ventilation is an available measure to dilute the released toxic gas and has been widely applied in offshore facilities to mitigate the adverse impact. However, “available” is never the same as “effective”. Up to now, the mitigation performance of ventilation remains a challenging topic that needs to be further studied. To identify the effectiveness of the mitigation, a systematic approach is proposed concerning the toxic impact caused by the diluted toxic gas, during which the emergency evacuation is considered. The grid-based concept is adopted to identify the initial position with the worst toxic impact. Then the effectiveness of ventilation is estimated according to its ability on mitigating the worst toxic impact. Taking an offshore platform as a case, the toxic impact under different H₂S leakage scenarios are predicted. The dependencies among the wind speed, leakage rate, concentration of H₂S, and toxic impact are discussed. Some safety-related results can be obtained, such as accident scenarios where ventilation can effectively mitigate the toxic impact. The present work could provide guidance to improve the safety of design and emergence plans in H₂S release accidents.

通风是一种用于稀释释放出的有毒气体的有效措施，并且已广泛应用于海上设施以减轻不利影响。但是，“可用”永远与“有效”相同。到目前为止，通风的缓解性能仍然是一个具有挑战性的话题，需要进一步研究。为了确定缓解措施的有效性，提出了一种关于由稀释有毒气体引起的有毒影响的系统方法，在此期间应考虑紧急疏散。采用基于网格的概念来确定毒性影响最严重的初始位置。然后根据通风的缓解最坏的毒性影响的能力来评估通风的有效性。以离岸平台为例，不同H ₂下的毒性影响可以预测S个泄漏情况。讨论了风速，泄漏率，H ₂ S浓度和毒性影响之间的相关性。可以获得一些与安全相关的结果，例如在事故场景中通风可以有效减轻毒性影响。当前的工作可以为提高H ₂ S释放事故的设计和应急计划的安全性提供指导。