CA2604118A1

CA2604118A1 - A system and method for real-time prognostics analysis and residual life assessment of machine components

Info

Publication number: CA2604118A1
Application number: CA 2604118
Authority: CA
Inventors: Ashok Ak Koul
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-01
Filing date: 2007-11-01
Publication date: 2008-04-23
Anticipated expiration: 2027-11-01
Also published as: CA2604118C

Abstract

A method and a system called XactLIFE for providing continuous (real-time) prognostics analysis and display of the changes in the fracture critical locations and life consumption and residual (remaining) life of multiple turbine engine components by conducting physics based loads and damage analysis as a function of actual engine usage and changing engine operating environment. Each engine control system is connected to an interface and to a data analysis and a prognostics processor unit and routinely monitored engine parameters such as engine speed, TIT
or EGT, ambient temperature and pressure and cooling airflow are measured in real--time. Data artefacts are removed and rule-based mission profile analysis is conducted to determine the mission variability and this in turn yields variability in the type of thermal-mechanical loads that an engine is subjected to during use.
This is followed by combustor modeling to predict the combustion liner temperatures and combustion nozzle plane temperature distributions as a function of engine usage and this is further followed by off-design engine modeling to determine the pitch-line temperatures in hot gas path components and thermodynamic modeling to compute the component temperature profiles of gas path components for different stages of the turbine. This is automatically followed by finite element (FE) based non-linear stress-strain analysis using an real-time FE solver and physics based damage accumulation, life consumption and residual life prediction analyses using internal state variable (microstructural modeling) based damage and fracture analysis techniques. The system is capable of dealing with components that are manufactured out of metallic, ceramic or a combination of both types of components.

Claims

1. A method and a system called XactLIFE for continuously monitoring variability of engine operating parameters and engine operating environment and predicting the usage and operating environment based life consumption and residual life of multiple components using standard data acquired from engine monitoring interfaces, comprising steps of: collecting and analyzing the data points (engine speed, TIT or EGT, ambient temperature and pressure and cooling airflow) acquired by each monitoring interface for assessing the type of loads (creep and/or fatigue) the monitored components are subjected to during service; continuously computing and quantifying the thermal-mechanical loads and quantifying the damage accumulated due to these loads using the physics of deformation and fracture processes operative in different components that allows the computation and identification of fracture critical location, estimation of life consumption and residual life of each component being monitored and fluctuations in specific component life parameters over time and continuously displaying the variability of fracture critical location and life for each component monitored; the methods followed in the proposed system are unique because the entire process of following different analytical techniques, related to different fields of gas turbine engineering, is conducted continuously in a logical sequence with the aid of appropriate graphical user interfaces and physics based modeling techniques. In addition, the uniqueness of the approach also lies in the use of physics based damage models as opposed to using empirical models, as is done by the OEM off-line, as a function of actual real-time engine usage, without using correlation coefficients or factors in the XactLIFE real-time system.

2. The method and the system as claimed in claim 1, further comprising a step of selecting a method of continuously computing variability of centrifugal loads and steady state as well as cyclic temperatures to establish the types of thermal-mechanical loads seen by the components using variability analysis, for each of the components monitored real-time.

3. The method and the system as claimed in claim 2, wherein the step of removing artifacts uses a rainflow analysis technique in combination with a homologous temperature plot to identify undesirable data points.

4. The method and the system as claimed in any of 1 to 3, further comprising a step of selecting a method of continuously computing variability of combustor liner temperature and combustor nozzle plane temperature profile as a function of engine usage real-time.

5. The method and the system as claimed in any of 1 to 4, further comprising a step of selecting a method of continuously computing variability of combustor liner temperature and combustor nozzle plane temperature profile as a function of engine usage real-time.

6. The method and the system as claimed in any of 1 to 5, further comprising a step of selecting a method of continuously computing variability of pitch-line temperature for different turbine gas path stages as a function of engine off-design usage conditions real-time.

7. The method and the system as claimed in any of 1 to 6, further comprising a step of selecting a thermodynamic modeling method of continuously computing variability of two dimensional temperature profiles for different turbine gas path stages as a function of engine usage conditions real-time.

8. The method and the system as claimed in any of 1 to 7, further comprising a step of selecting a heat transfer modeling method of continuously computing variability of temperature profiles for different turbine gas path stages as a function of engine usage conditions real-time.

9. The method and the system as claimed in any of 1 to 8, further comprising a step of selecting a heat transfer modeling method of continuously computing variability of temperature profiles for different turbine stages for non-gas path components as a function of engine usage conditions real-time.

10. The method and the system as claimed in any of 1 to 9, further comprising a step of selecting a non-linear finite element modeling based method of continuously computing variability of stress, strain and temperature profiles for different turbine components being monitored as a function of engine usage conditions real-time.

11. The method and the system as claimed in any of 1 to 10, further comprising a step of selecting physics based damage modeling method of continuously computing variability of distortion based fracture critical locations, life consumption, residual life and inspection interval for different turbine components being monitored as a function of engine usage conditions real-time.

12. The method and the system as claimed in any of 1 to 11, further comprising a step of selecting physics based damage modeling method of continuously computing variability of surface condition based fracture critical locations, life consumption, residual life and inspection interval for different turbine components being monitored as a function of engine usage conditions real-time.

13. The method and the system as claimed in any of 1 to 12, further comprising a step of selecting physics based damage and fracture modeling method of continuously computing variability of crack nucleation based fracture critical locations, life consumption and residual life for different turbine components being monitored as a function of engine usage conditions real-time.

14. The method and the system as claimed in any of 1 to 13, further comprising a step of selecting physics based fracture modeling method of continuously computing variability of crack propagation based fracture critical locations, life consumption, residual life and safe inspection intervals for different turbine components being monitored as a function of engine usage conditions real-time.

15. The method as claimed in any of 1 to 14, further comprising a step of selecting which of the variability of component parameters such as stress, strain and temperature profiles and the prognostics results such as the fracture critical location, surface condition, distortion, crack nucleation life and crack propagation life for which a representation of the variability is to be displayed.