Improvement of turbine blade lifetime assessment by more accurate estimation of the thermal boundary conditions:

摘要

The known studies in the area of gas turbine lifetime prediction do not result in the algorithms for on-line engine monitoring. This article introduces and investigates a new method for developing “light” mathematical models to estimate static thermal boundary conditions for gas turbine hot elements. In contrast to the previous developments, these models allow on-line lifetime monitoring of such elements. The blade of the high-pressure turbine of a two-spool free turbine power plant was chosen as a test case. The models of blade boundary conditions were developed based on well-known thermodynamic relations and a steady-state nonlinear physics-based model of this engine. Many candidate models are analyzed in the article, and the best models are selected by their accuracy and robustness to engine faults using instrumental and truncation errors as criteria. The instrumentation errors are induced by measurement inaccuracy of gas path variables used. For the analysis of the model robustness, the truncation err...