Research On Computer Aided Hazop Analysis Based On Sdg Model And Its Application

With the development of science and technology, the scale of production gets larger and larger and the process becomes more and more complex in process industry. As a result, the probability and damage of hazard is on the increase. The safety problem has been a core problem for the government and related enterprises.This paper focuses on a set of systematic SDG-HAZOP (hazard and operability analysis based on signed directed graph) methods, which include SDG modeling, SDG model inference and expression of analysis results, In addition, a case study has been applied.This paper comprises7chapters. The main contents are as follows:At first, safety problems and the background of this project is illustrated. Then many methods of PHA (process hazard analysis) are studied, especially HAZOP (hazard and operability) analysis. Besides, SDG (signed directed graph) technology is deeply studied. Precise mathematics definition of SDG and related conceptions are presented Then expressing SDG model with matrix is proposed. The development of SDG technology in the safety engineering field is also analyzed.SDG modeling methods for hazard evaluation are studied. Firstly, requirements to SDG evaluation models are put forward. Then SDG modeling methods abroad are analyzed. The existing methods of SDG modeling don’t differentiate between hazard evaluation and fault diagnosis. Further more, these methods have many disadvantages, for example complex models and hard deduction. A set of SDG modeling methods for hazard evaluation based on major hazards is brought forward, which avoids above disadvantages. A case study for SDG modeling is applied. The methods of optimizing SDG evaluation model are studied. SDG model is a qualitative model. So its uncertainty easily results in false consistent paths. Besides, the HAZOP analysis results based on SDG model are complicated, which may bring on information explosion. This paper puts forward optimizing SDG models in the following three aspects:simplification during modeling, simplification after modeling and multiple case studies. Moreover, detailed rules and methods are given in this paper.The inference of SDG evaluation model and expression of analysis results is studied. Bidirectional inference is adopted in manual HAZOP analysis. But it is laborious, time-consuming and easy to miss important faults. This paper introduces reverse inference based on major hazards into SDG-HAZOP analysis. Based on studying the result table of manual HAZOP analysis, this paper designs result table of SDG-HAZOP analysis. The result table can not only show abnormal causes and adverse consequences, but also show consistent paths. In addition, SDG-HAZOP analysis results can be automatically imported in a table by a set of software.Computer aided SDG-HAZOP analysis is studied. At first, the development of computer aided HAZOP analysis is analyzed. In current SDG-HAZOP research, scholars from all over the world face a same problem:lack of an effective tool of SDG to perform modeling, deduction and experiment. This paper presents developing one SDG modeling and inference software platform according to the research requirements and detailed functional requirements are also put forward. Besides, detailed comparison study is carried out between computer aided SDG-HAZOP analysis and manual HAZOP analysis.SDG-HAZOP analysis of200,000ton per annum cinnamene equipment has been accomplished. The exactness of SDG modeling method, SDG model inference and table format is validated. Superiority of SDG-HAZOP analysis is approved by comparing with manual HAZOP analysis results.At last, research results and innovation contents are summarized, and expectation of future study about SDG-HAZOP analysis is listed.The paper studies a set of integrated methods of computer aided SDG-HAZOP analysis. Its research contents cover with modeling, inference, expression of analysis results, industry case study and so on. The research results and innovation contents are as follows: (1) Proposed a set of systematic modeling methods of SDG evaluation model based on major hazards.The core of models is major hazards. Through adding cause nodes and consequence nodes, SDG model is transferred to SDG evaluation model. Based on above research, this paper proposes a set of systematic special modeling methods of SDG evaluation model.(2) Proposed a set of optimizing methods of SDG evaluation model.The paper proposes a set of feasible optimizing methods of SDG evaluation model, which includes simplification during modeling, simplification after modeling and multiple case studies.(3) Proposed one new inference mode of SDG evaluation model.The paper proposes a new inference mode:reverse inference based on major hazards. Compared with bidirectional inference and positive inference, this inference is more suitable for SDG-HAZOP analysis.(4) Proposed a set of systematic methods of computer aided SDG-HAZOP analysis.This paper research and develop a set of systematic methods of computer aided SDG-HAZOP analysis, which has brought into industrialization. The method has many advantages:high completeness, high inference depth, saving time and labor, good repeatability, etc.(5) Accomplished computer aided SDG-HAZOP analysis of200,000ton per annum cinnamene equipment.Based on above research, SDG-HAZOP analysis of200,000ton per annum cinnamene equipment has been accomplished. For the first time in China, HAZOP inference in the whole process has been automatically accomplished and SDG-HAZOP analysis report tables have been automatically realized on computer. Analysis results not only contain main contents of manual HAZOP analysis, but also comprise accidents which have happened in recent years. SDG-HAZOP analysis is superior to manual HAZOP analysis on inference depth, expression of analysis results, repeatability, etc.