基于2GW-HAZOP与偏离度的输气站降压排污作业风险评估

Risk assessment on depressurization and sewage discharge operation in gas transmission stations based on 2GW-HAZOP and deviation degree

为预防输气站降压排污过程中发生事故,提出1种基于2GW-HAZOP与偏离度的作业过程风险评估方法。在HAZOP方法的基础上定义作业偏差,将传统7种工艺参数偏差引导词映射到1个偏差二元组中;通过将作业过程节点功能作为参量,采用节点跨越和节点功能偏离2种引导词,从而构建节点功能偏差;进一步通过定义功能偏离度和控制措施偏离度对偏差进行量化处理,表征风险水平;将方法应用于降压排污作业过程的风险评估中,可分析得到偏离度大的作业过程节点。结果表明:分离器放空不充分、排污池液位过高或过低、排污结束未检查泄漏情况的偏离度较大,需加强风险控制。

In order to prevent the accidents in the depressurization and sewage discharge process of gas transmission station,a risk assessment method of the operational process based on 2GW-HAZOP and deviation degrees was developed.The operation deviation was defined on the basis of HAZAP method,and the guide words for the deviation of traditional 7 kinds of process parameters were mapped into a deviation two-tuple.By using the node functions of operation process as the parameters,two types of guide words of node crossing and node function deviation were adopted to construct the node function deviation.Further,the deviation was quantified by defining the deviation degrees of function and control measures,and the risk level was characterized.The method was applied in the risk assessment of the depressurization and sewage discharge operation process,and the operation process nodes with large deviation degree were analyzed.The results showed that the deviation degrees of inadequate venting of separator,too high or low liquid level of sewage tank,and sewage discharge completed without checking leakage were large,and the risk control should be strengthened.