Refurbishment of turbogenerators for plant life extension

The need to replace major components of turbine generators depends on their expected reliability over future operating periods. Assessment of the reliability should take account of operating experience for the particular design of generator and of the condition of lead units judged from detailed inspection and NDT testing during overhaul. However, the expected reliability is only one element of the economic assessment. The decision to exchange plant will necessarily be made by the utility, taking account of such external factors as the availability of spare capacity on the system and the cost of operating replacement plant. The authors discuss various aspects of turbogenerators refurbishment concerned with the rotors and stators