基于不同评估规范的过热器联箱蠕变 疲劳损伤分析

Supercritical unit superheater outlet headers operate under chronic high-temperature and high-pressure conditions, the frequent start-stops and long-time steady state operations under high temperature lead to typical creep-fatigue damages in the header. An appropriate method should thus be selected to eval-uate the damage state of the unit to ensure long-term steady operation of supercritical units. A numerical simulation based on finite element software Abaqus was carried out on the superheater header of a super-critical power generation unit. During the operation of the unit, the distribution of stress on the header was obtained, and the damage was evaluated with three different codes: ASME-III. RCC-MRx and R5, re-spectively. Results show good agreement in the allowable time evaluated by the ASME-III code with the maintenance life, conservative and overpredicted damage by the RCC-MRx code, and underpredicted dam-age by the R5 code with significantly less damage than the other codes. Therefore, the ASME-III code should be selected first as the criteria of the damage evaluation for this type of equipment, and the R5 code can be used as an alternative when the ASME-III code gives conservative results.