关键词: 液氨罐区, HAZOP, SIL定级, 保护层, 安全仪表系统, liquid ammonia tank farm, HAZOP, SILgrading, protection layers, safety instrument system

Abstract: This paper takes liquid ammonia tank farm as an example, Through HAZOP analysis and other risk analysis methods, all potential risk scenarios of the system are identified. At the risk assessment stage, the scenarios identified by the HAZOP analysis are semi-quantitatively analyzed through SIL grading. The consequence severity level and the failure probability when the independent protection layer is required are evaluated to determine the system's SIL level requirements.. After choosing the SIS system, SIL is used to check that the SIS system meets the requirement of SIL grading. By above methods, the identified risk of process can be reduced to the reasonable scope.