The challenge

• Flexible plant use could mean actual service life of collectors in super-critical steam generators is shorter than the calculated service life
• These collectors are constructed with a reduced wall thickness to optimise use under flexible conditions
• The interim result from operational monitoring is that the designed service life is not being achieved.

Method

Step 1, R&D:

• Generate material data and optimise calculation method
• Base material: Scatter band analysis
• Weld seam: Weld reduction factor
• Flexible operation: Interactions between creep and fatigue

Step 2, Component assessment:

• Reassessment of actual service life based on representative actual material data with new calculation methods

Objective

• Robust service life assessment to guarantee or make existing predictions more specific