Early Detection of Combustor Pulsations and Optimized Operation Through On-Line Monitoring Systems

Abstract

This article describes the objectives of an on-line monitoring system, the development and capabilities of the system and the experiences gained with it. The objectives of the monitoring system were formulated after several transition pieces between the combustor and the turbine inlet had failed. The failures occurred within less than two months in a plant that had operated for more than 7 years without unusual problems. The system development was based on this experience and the goal to prevent future catastrophic failures. It provides: • Data logs of selectable operational parameters • Combustor pressure pulsations including a frequency spectrum • True firing temperature based on a heat balance calculation It thus provides the basis for predictive maintenance and optimum equipment performance. Several gas turbines with low NOx combustion system were equipped with the monitoring system in the summer of 1997. Data provided by the system over a period of almost 3 years identifies several parameters that are very indicative of the condition of the equipment. These parameters are discussed as well as the consequences for the operation, maintenance and reliability of the units.