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Full-Text Articles in Nuclear Engineering
On-Line Structural Integrity Monitoring And Defect Diagnosis Of Steam Generators Using Analysis Of Guided Acoustic Waves, Baofu Lu
Doctoral Dissertations
Integrity monitoring and flaw diagnostics of flat beams and tubular structures was investigated in this research using guided acoustic signals. The primary objective was to study the feasibility of using imbedded sensors for monitoring steam generator and heat exchanger tubing. A piezo-sensor suite was deployed to activate and collect Lamb wave signals that propagate along metallic specimens. The dispersion curves of Lamb waves along plate and tubular structures were generated through numerical analysis. Several advanced techniques were explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang transform (HHT) is a recently developed technique for the analysis …
An Integrated Approach To Performance Monitoring And Fault Diagnosis Of Nuclear Power Systems, Ke Zhao
An Integrated Approach To Performance Monitoring And Fault Diagnosis Of Nuclear Power Systems, Ke Zhao
Doctoral Dissertations
In this dissertation an integrated framework of process performance monitoring and fault diagnosis was developed for nuclear power systems using robust data driven model based methods, which comprises thermal hydraulic simulation, data driven modeling, identification of model uncertainty, and robust residual generator design for fault detection and isolation. In the applications to nuclear power systems, on the one hand, historical data are often not able to characterize the relationships among process variables because operating setpoints may change and thermal fluid components such as steam generators and heat exchangers may experience degradation. On the other hand, first-principle models always have uncertainty …