Process faults impact analysis on the performance of the steam cycle of a combined cycle gas turbine
Résumé
The increase in renewable energy sources in electricity production necessitates, in the short term, the use of flexible plants such as Combined Cycle Gas Turbines (CCGT), which will be operated in a more dynamic manner. Maintaining their efficiency and availability is crucial during these new operating conditions. This can be accomplished using model-based faults detection and diagnostic (FDD) tools, which leverage the benefits of digital twins and instrumentation to automatically identify efficiency losses and potential causes of outages. Currently, these tools are effective for steady-state operations. While dynamic models of power plants are already developed, the modeling and impact analysis of faults during transient operations is still not well covered. This study focuses on analyzing the faults impact on the performance of the steam cycle of a CCGT. First, a list of potential faults that occur on the components is presented based on the literature and operator experience. Then, a dynamic model of an industrial steam cycle, calibrated on industrial data, is used to simulate the impact of faults during steady-state and dynamic operations. The delays related to the thermal inertia of heavy components like heat exchangers, and the control system makes this analysis challenging in order to distinguish the impact of faults from other phenomena. The stability of the fault impacts during load variation and in various conditions is assessed.