Case study: maintenance cost optimization through on-condition maintenance schedules and advanced component repairs

摘要

The main costs in gas turbine maintenance are the cost of major hot section overhaul and the cost of hot section replacement parts. This paper presents two methods that have been used to reduce these cost drivers. Conventionally, overhauls are scheduled based on generalized formulas for operating hours provided by the OEM for each engine model. On-Condition Maintenance scheduling uses a computer model to monitor the condition of the key hot section components, and enables the overhaul to occur at the optimum time for each engine in the fleet. This method has the advantage of extending the time between overhauls, while ensuring that the components are repairable at the time of overhaul. After one or two service intervals, hot section components are typically retired based on OEM service bulletin instructions. Laboratory analysis can be performed on parts removed from service to determine the factors limiting further service. Advanced repair processes are then applied to correct the life limiting factors and enable the parts to be reliably returned for further service, and extend the total life cycle of the parts through to retirement. The paper uses a case study based on a fleet of GE LM1600 engines to demonstrate how these practices have been applied to extend engine service intervals, and component life cycles, to reduce maintenance costs for the operator's fleet.