Computer-aided Operability Study

在本研究中，面向对象的方法，计算机辅助HAZOP已经开发出的VTT自动化公司在1997年至1999年在芬兰合作。HAZOP系统基本上由知识库（工厂专业知识库，一般知识库）和推理机。HAZOP系统中的一般知识包括元件故障模型和建议措施知识。变量偏差和元件故障模式之间的因果关系被建模为HAZOP系统中的元件故障模型。所需的行动分为针对原因的行动和针对后果的行动。关于原因和后果的行动的知识分别包括预防和检测、缓解和检测。该知识以独立于工艺的方式开发，适用于各种工艺流程。工厂特定知识包括有关物料、反应和工厂结构（P和ID）的信息。工厂特定知识因工厂而异，必须由用户提供。用户通过图形用户界面与系统交互。在HAZOP系统图形编辑器中，用户可以方便地绘制出过程布置组件图标的P和ID。一旦P和ID输入到系统中，相应的组件故障将以适当的方式自动连接到内部。HAZOP分析通过在P和ID中指定工艺单元或管道中的过程变量偏差来启动。通过知识库的搜索，对设备的各个过程变量进行顺序学习，用关键词描述偏差，并采用面向对象的体系结构，使用专家系统外壳G2实现了HAZOP系统。

In this research, an object-oriented approach for computer-aided HAZOP has been developed by collaboration with VTT Automation in Finland from 1997 to 1999.The HAZOP System consists basically of the knowledge bases (the plant sepcific knowledge base, the generic knowledge base ) and the inference engine. The generic knowledge in the HAZOP System consists of components malfunction models and suggested action knowledge. Causal relationships between variable deviations and failure modes for components are modeled as component malfunction models in the HAZOP System. Actions required are divided into actions for the cause and actions for the consequence. Knowledge of actions for the cause and the consequence consist of prevention and detection, mitigation and detection respectively. This knowledge is developed in a process-independent manner and is applicable to wide variety of process flow sheets.The plant specific knowledge consists of information about materials, reactions, and the plant structure (P and IDs). The plant specific knowledge varies from plant to plant and has to be provided by the user. The user interacts with the system through the graphical user interface. The user can easily draw the P and IDs of the process arranging component icons in the HAZOP System graphical editor. Once the P and IDs is input into the system, the corresponding component malfunction gets connected automatically internally in the appropriate manner.HAZOP analysis is initiated by specifying a process variable deviation in a process unit or pipeline in the P and IDs. Each process variable of equipment is studied in sequence by searching the knowledge base, using key words to describe deviations.The HAZOP System for this work is implemented in an object-oriented architecture using expert system shell G2.