High temperature component integrity in turbines required for flexible operation – evaluating assessment effectiveness

Figures & data

Figure 1. Examples of turbine component-feature specimen tests.

Figure 2. Examples of isothermal thick-wall section pressure vessel component-feature specimen benchmark tests.

Figure 3. Schematic representation of influence of relatively slow (continuous grey lines) and relatively fast (solid black broken lines) heating/cooling rates on thermal strain generation at a critical turbine feature location.

Figure 4. Schematic representation of simplified HP turbine service cycle adopted for isothermal benchmark testing.

Figure 5. Example of turbine component-feature specimen, service-cycle TMF testing arrangement.

Figure 6. Representations of (a) hot-start, (b) warm-start, and (c) cold-start TMF service cycles for a blade root fixing in a high temperature 1%CrMoV turbine rotor (as adopted in [12]).

Figure 7. Common steps in a number of published creep-fatigue assessment procedures (e.g. [20–23].

Figure 8. Damage development in 1%CrMoV TMF specimens subjected to (a) a hot-start TMF cycle, (b) a warm-start TMF cycle, and (c) a cold-start TMF cycle (see Figure 6).

Figure 9. Comparison of enhanced FEA rotor blade-fixing root (numerical) stress/strain hysteresis response with that applied (experimental) in a feature specimen, service-cycle TMF test [13].