E- & F-Class Rotor Failure Mechanisms and Lifetime Extensions
(Room Garuda 10B, 1st Floor)
18 Sep 18
4:00 PM
-
5:30 PM
Tracks:
TRACK C - Optimizing Plant Operation
E- & F-Class Heavy Duty Gas Turbine Owners and Operators are routinely feeling the pinch of decreasing operating and maintenance budgets. As such, users are demanding improved life cycle maintenance costs and longer lives out of capital equipment. While E-Class engines have fully matured, F-Class units are now approaching the mature status, with rotors finally approaching the OEM-recommended end of life. The result is that many operators are faced with the dilemma to continue operation of rotors beyond the OEM-recommendations or to perform an overhaul and assessment on their components. With the cost of some rotors exceeding $20M USD, rotor purchases may not be a viable solution for many operators. Forced to identify other solutions, users have been investigating lifetime evaluation and extension programs from OEMs and third parties. During such inspections, a multitude of non-destructive testing methods are used to thoroughly inspect components for damage. The results are then coupled back to thermal and structural analyses to understand the impact of the damage on the useful remaining life of the rotor. In some cases, the rotor is suitable to return to service, whereas others may require targeted replacement of individual disks or bolts to return to service. Ultimately, the end goal is to prolong the life of the rotor and avoid unnecessary retirement of sound components. The goal of this paper is to highlight some of the recent findings on multiple heavy duty gas turbine rotors that have undergone comprehensive lifetime inspections and evaluations. Mitigations and recommendations on repair will be provided, as will solutions to common problems during the course of typical rotor overhauls.