Research Of Risk Assessment And Safety Instrumented Function Assessment Technologies In Petrochemical Plant

Risk assessment technology is considered as an effective measure ofidentifying the potential risk. As a quantitative risk assessment, Hazardand Operability study (HAZOP) has played an important role. But it isstill weak in analyzing whether the protection layers are enough. HAZOPand Layer of Protection Analysis (LOPA) are combined and asemi-quantitative risk assessment method is raised in this thesis, whichunites the advantages of both two methods perfectly. An engineeringproject is researched, which confirms that more effective risk assessmentcan be achieved by using HAZOP/LOPA. However, a semi-quantitativerisk assessment method can not define the risk of a complicatedequipment or process exactly. Quantitative Risk Assessment (QRA)technology can solve this problem well and which is recommended to bea supplement of HAZOP/LOPA. As a result, the "HAZOP/LOPA+QRA"methodology for risk assessment is established.Safety Instrumented System (SIS) is a device widely used in petrochemical plant to protect the system safety. Safety InstrumentedFunction executed by SIS is the last line of defense of preventing thefailure events. An audio-visual model based on IEC61508/61511isestablished in this thesis. The application of LOPA based SILdetermination technology is researched detailed. Meanwhile, SILvalidation technologies based on (Reliability Block Diagram) RBD, FTA(Fault Tree Analysis) and Markov Model are researched. The threemethods are compared by a project and the"LOPA+Markov"methodology for SIF assessment is established.