Research On The Simulation And Guidance Improvement For Chemical Process HAZOP Analysis

The development of the human society has increased the need for chemical product. That makes the chemical system run at full capacity and the processes are becoming more complex. Hence, the frequent accident is inevitable. Complete identification of the potential hazards in the chemical process, as well as full protection of the safety measures, has drawn attention of the researchers. HAZOP (Hazard and Operability) analysis is the most popular and effective process hazard analysis method at present. It can be used in the design of the safety instrumented systems.The traditional HAZOP method uses the different professional knowledge of the experts. It is systematic method and easy for completion. However, traditional HAZOP is inherently a qualitative method. It is a highly time and effort cconsumption process.1. According to fact that traditional HAZOP qualitatively and discretely analyze the chemical systems, we propose the new HAZOP framework based on dynamic simulation and safety-state transition digraph. We divide the safety-state space of the sections into 4 parts and use dynamic simulation to explore the global effect of the deviation, including the transition of the system safety state. At the same time, it can accurately analyze and develop the performance of the safety systems to prevent serious accident. The comparison to the traditional HAZOP method proves that the framework can aid the traditional HAZOP and study the process in depth.2. In order to analyze "High Temperature" deviation in the HAZOP of tubular fixed bed reactors, we prove and use the system divergence criterion to define the runaway boundaries of the reactors. PA (Phthalic Anhydride) reactor is used as case study. The divergence criterion can be used to effectively explore influence of the deviation on the reactor thermal safety and the causes of the deviation. Further more, dynamic simulation is executed to successfully verify that the system dynamic divergence can forecast thermal runaway of the reactors. Hence, the operators and the emergency systems can have more time to response. The results can be directly employed to aid the completion of the safety instrumented systems conceptual design for the reactor. 3. According to the highly time consumption of the traditional HAZOP, we proposed the preorder guidance method to aid HAZOP and implemented it in a semi-automatic guidance software SimHAZOP using Matlab.We build the deviation knowledge base, including the causes and consequences. After the experts divided the process into separate nodes, SimHAZOP can automatically match the nodes with the deviations in the knowledge base, generating the preliminary HAZOP worksheet including the nodes, deviations, causes and their consequences. The expert can improve the analysis based on this worksheet. At the same time, SimHAZOP can interact with Aspen Plus and generate 3-D risk matrix graph of the deviations.