Gas Turbine Condition Monitoring and Diagnostics

Gas turbine monitoring and diagnostics belong to a common area of condition monitoring (health monitoring) of machinery and mechanical equipment such as spacecrafts, aircrafts, shipboard systems, various power plants and industrial and manufacturing processes. They can be considered as complex engineering systems and become more sophisticated during their further development that results in potential degradation of system reliability. In order to keep reliability high, various diagnostic tools are applied. Being capable to detect and identify incipient faults, they reduce the rate of gross failures. Considerable increase of industrial accidents and disasters has been observed in the last decades (Rao, 1996). Mechanical failures cause a considerable percentage of such accidents. Various deterioration factors can be responsible for these failures. Among them, the most common factors that degrade a healthy condition of machines are vibration, shock, noise, heat, cold, dust, corrosion, humidity, rain, oil debris, flow, pressure, and speed (Rao, 1996). In these conditions, health monitoring has become an important and rapidly developing discipline which allows effective machines maintenance. In two last decades the development of monitoring tools has been accelerated by advances in information technology, particularly, in instrumentation, communication techniques, and computer technology. Modern sensors trend to preliminary signal processing (filtering, compressing, etc.) in order to realize self-diagnostics, reduce measurement errors, and decrease volume of data for subsequent processing. So, sensors become more and more “intelligent” or “smart”. Development of communication techniques, in particular, wireless technologies drastically simplifies data acquisition in the sites of machine operation. Data transmission to centralized diagnostic centres is also accelerated. In these centres great volume of data can effectively be analyzed by qualified personnel. The personal computer has radically changed as well. Large numbers of powerful PCs united in networks allow easy sharing the measured data through the company, fast data processing, and suitable access to the diagnostic results. Development of the PC technology also allows many independent disciplines to be integrated in condition monitoring. Success of monitoring not only depends on perfection of monitoring hardware and software themselves, but also is determined by tight monitoring integration with maintenance when the both disciplines can be considered as one multidiscipline. Behind this trend lies a well