Study Of The Computer-Aided HAZOP Analysis Of Batch Processes

It's a popular subject to study the computer-aided HAZOP analysis as an assistant to the manual work, which is a time-and-cost consuming work. The existing methods of computer-aided HAZOP are mostly about continuous chemical processes. Because all the in continuous processes such as batch processes have the characteristics of discrete and nonlinear, it is hard to realize computerizing.In this article, an integrated model combined with Petri net and SDG (Signed Directed Graph) has been presented firstly, which is the first method of modeling. However, this method has advantages. For example, it cannot contain more information about the material information and the hardware fault information. In addition, it cannot be reused and expanded. Therefore, an object oriented model which is based on the Discrete Event System (DES) modeling theory and system safety theory has been brought forward. This model is a combination of the Petri Net and SDG and is applied to carry out the HAZOP analysis of batch processes. It composed of four levels, they are control level, device level and variable level and measurement level. In each level, there are input and output information and each level's own activities. One of the advantages of the method is that it utilized the good characteristics of Petri Net to describe the normal work conditions. The other one is that it also utilized the advantages of SDG models, which has a grate ability to deduce the road of fault and search its abnormal reasons and adverse results.The model can be reused and expanded. It can partly replace human work. In addition, at the end of this paper, an industrial case has been introduced to test the model. One work is use the model to analysis accidents in history; another work is using it to take the safety analysis.At the end of this paper, there is a chapter especially for the description of a new thinking method to modeling. In this method, SDG plays an important role. And the Petri net is an assistant model to active SDG. This method can be used as an extension for latter study. In addition, there is an analysis of these three models presented in this paper.