Abstract
Rotor constitutes one of the critical components of steam turbine. Steam turbine rotor undergoes severe thermal transients during start up and shut down. When steam turbine starts up, temperature of rotor surface gradually rises with the incoming steam temperature. During this process temperature rise of central part lags behind that of rotor surface, resulting in extreme compressive stresses developed within the rotor. Similarly, the rotor surface is subjected to tensile stresses during the cooling down in the shutdown process. After a certain number of cycles, the surface or core of rotor may generate cracks due to low cycle fatigue (LCF) phenomena. Steam turbine unit for advanced ultra-super-critical (AUSC) power plant works under very high pressure and temperature, constituting a severe working environment. For steam turbine rotor, Alloy 617 M is planned to be used for the first time. Hence, it is required to test the rotor in rotating condition in a high-temperature spin rest rig before putting into actual operation. To test the AUSC turbine rotor in a high-temperature test rig, it is required to simulate the radial temperature gradient to achieve the required thermal stress in the rotor. No standard test protocol exists for the accelerated LCF testing for the rotor. A test protocol is developed for Accelerated Creep and Transient Thermo-mechanical testing of the AUSC steam turbine rotor at high temperature taking the guideline from the existing ASME standard.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call