Industrial Safety Assessment Based On System Functional Theory

The power plant is a complex system of structures, machinery, associated management, environment and equipment for generating electric energy from firepower energy. The hazards about power plant occur frequently, and result in consequence accidents. The methodology research of safety assessment for power plant is very important considering synthetical management safety, environment protection and safety in equipment operation. Also, it is very significant for us to construct a safety assessment system and define a desired safety goal in terms of system approach.In the thesis, the safety of the power plant as the research object, and try to analyse every kind of factor which affect the safety of power plant with using the perspective of system analysis. According to present situation of safety assessment for power plants, a mathematical model and approach for them are proposed, in which the key factors influencing the power plants safety are considered; on the basis of establishing multi-hierarchy valuation structure for power plants, by use of system functionality and analytical hierarchy process(AHP)a preponderant function of system safety is constructed to solve the problem that the system safety function preponderates over the weight sum of safety functions of sub-systems. In order to offer scientific foundation and simulation approach for safety assessment analysis and decision-making to safety management department in power plant, the coordination of interaction among safety assessment factors of power plant is integrated. Practical applications show that by use of the proposed mathematical model and method the safety assessment of power plants can be effectively conducted. In addition, we propose a professional websites of safety assessment which based on browser/server model to realize the safety assessment expert of differ region carry through safety assessment for differ power plant synchronously. The websites which based on the model view controller programming model is constructed with using Java server Page, and systemic feasibility is validated. To resolve the systemic question and real time assessment question in the safety analyse assessment. To improve operability, continuity, extend of safety analyse assessment through actualizing simulation supporting platform of system safety assessment.In addition, a fault prediction approach for process plants using fault tree analysis is presented in the presence of no or false information of certain sensor in the test. The fault propagation model is constructed by causal relationships from fault tree analysis (FTA). Knowledge about system failure, which is obtained from the fault propagation model, is represented as abnormality patterns in process variables and stored in the knowledge base. The prediction system can identify the cause of system malfunction considering no or false information of sensors by matching the pattern data from process plants with the abnormality pattern in the knowledge base. From unavailability of basic events and sensors, the estimated rates are provided for sequence checking in fault prediction. The proposed approach is applied successfully to a reactor control and protection system (RCPS).It is a promote effect that use a new mathematical model and method to resolve safety question of industry system in the test, and also established foundation for the next study on the aspect of safety assessment. In addition, it has reference and values for the safety assessment of the other industrial and society circle with using the methodology and technology which are presented in the thesis.