This document summarizes an experimental investigation into the thermal behavior of steam turbine components during natural cooling. Key points:
- Optical probes and thermocouples were used to measure the temperature of a steam turbine rotor and casings over 96 hours of natural cooling after shutdown.
- A 2D numerical model was developed to simulate the natural cooling process by replacing fluid buoyancy with an equivalent fluid conductivity based on experimental data.
- Measurements found the rotor and some casing locations initially increased in temperature after active cooling ended, then cooled over time.
- The results provide data to optimize steam turbines for flexible operation by better understanding how initial metal temperatures affect startup stresses and fatigue life.