Guidelines for Inspection, Monitoring, Repair, and Maintenance of HRSGs - Based on Review of Worldwide Plant and Research Experience

Background and Introduction In 2003 ETD held a successful International Conference and Workshop on HRSG Technology at which the importance of repair and maintenance technologies was recognised as a major factor in the successful and economic plant operation. As a relatively new, and rapidly evolving, technology HRSGs have had a history of faults, particularly in early models, which were not designed for cyclic/multi-shifting operation. While much work has been undertaken to improve design and reduce problems, operators are still facing a situation where HRSGs commonly require a high level of intervention by maintenance staff and can suffer in-service deterioration at high rates. This situation is aggravated by the limited access available to HRSG tubing for repair. The high density of finned tubing in the heat exchanger banks effectively prevents the repair of corrosion, or other, damage to the tubing, and tube plugging is often seen as the only answer.