Computer-aided Hazard And Operability Study System Based On Signed Directed Graph

The manual safety evaluation is not accurate, slow and complicated to operate, and it is time-consuming, costly. Therefore, to achieve computer-aided safety evaluation has become a principal aspect of the safety evaluation. Many scholars are conducting research in the field.The computer-aided safety evaluation based on SDG modeling is a major study which autos safety evaluation in recent years. Because SDG and HAZOP analytical methods are based on two-way inference mechanisms, SDG is the most effective method to complete automatically HAZOP now.The author summarized results which the most crucial issues of SDG-HAZOP analysis: the establishment of the craft process SDG model, and proposed the theory unifies the modeling method based on the flow chart and the practical experience.The modeling method greatly speeds up the SDG modeling and solves the problems that the process signal can not be automatic analysis and the results can not be chosen effectively in the past studies.On this basis, the author prepared CASH (computer-aided SDG-HAZOP) program by Using Visual Basic and processed the datum by the Access database. It realized the computer-aided HAZOP analysis. We established the pump system, heat exchanger systems, compressor systems, distillation systems, furnace system etc. SDG-HAZOP Analysis models, and obtained the disadvantageous consequences and abnormal reasons tables. It provides methods and materials to construct large-scale systems.We carried on the actual analysis to the 65t/h fuel oil boiler by using the constructed SDG-HAZOP program, and contrasted with the traditional HAZOP analysis results, the results showed: the computer-aided SDG-HAZOP finds 424 disadvantageous consequences which effective deviation causes, and 254 abnormal reasons which cause the deviations of the boiler systematic alarm nodes. It is bigger than the quantity by far which the artificial HAZOP analyzes. The same variable nodes, such as over-heated steam nodes CASH has founded 34 abnormal reasons, and the only 4 abnormal reasons by the artificial HAZOP analyzed. It indicates that the SDG-HAZOP analysis program has artificial HAZOP analyzes the incomparable superiority.HAZOP analysis based on SDG technology is easy to use, with the science and technology progress, developing the computer-aided HAZOP based on SDG technology is a main direction of the future safety evaluation. The computer-aided HAZOP based on SDG technology is a developing technology, it needs further improve and systematize in a lot of practice.