| Monitoring and fault diagnosis technology can ensure that the equipments run in a safety, reliable and efficient way in process industry. It plays a key role both in eliminating hidden fault and avoiding occurring of accident. This paper takes multi-level model (next for short as MFM) as the theoretical foundation, based on Zhejiang Province Scientific and Technological Projects "Distributed intelligence unit remote monitoring and fault diagnosis technology and systems research and development" (2007C21086), research on the fault diagnosis methods for process industry system, taking thermal power generating system as object. That can promote the development of science and technology. The main contents are as follows:The first chapter discussed the significance of fault diagnosis in process industry, described the development history and current status on fault diagnosis in process industry, reviewed the development and current status of MFM, and comparatively analyzed the advantages of MFM in the system fault diagnosis. Finally, the main contents and the overall framework of the thesis were presented with the specific requirements of scientific research projects.The second chapter analyzed the advantages and disadvantages of several common method of modeling, introduced the basic principles and the related concept of MFM, studied the method of modeling MFM, built MFM of a thermal power supply system, analyzed the causal dependency between the function in MFM, gave causal dependency graphs, presented the causal dependence matrix between the function which have multi-state in order to facilitate the application of computer in the calculation and analysis based on MFM.The third chapter analyzed the fault diagnostic technology based on MFM, summed up the process of fault diagnosis based on MFM, analyzed the attribute of the flow, the grouping of function, the rule of alarm analysis, presented the validation method of the measure value and the alarm state on the unknown functions, given the realization of the two diagnostic algorithms process. Finally the applicability of fault diagnostic algorithms based on the MFM is analyzed.The fourth chapter analyzed the composition, function and power production process of the thermal power systems, abstracted these equipments to get some corresponding goals, functions, physical components, built MFM of thermo-power generation system, given the application process of the modeling and fault diagnosis based on MFM for thermo-power generation system.The fifth chapter analyzed the requirements of fault diagnosis software of thermo-power generation system based on MFM, given the he framework of software system, designed the function modules of software, developed a thermal power fault diagnosis system and validated the system by the example.The sixth chapter sums up the work of the dissertation and presents conclusion and prospect. |
