Feedwater pumps are the heart of any steam generation process. As such, they are considered critical assets. Field pump performance testing provides experts with developed head, capacity and efficiency data under normal operating conditions. Deregulation has given rise to an open market where pump design point and actual operating point may no longer be equivalent and may vary significantly. Such market-driven conditions primarily affect combined-cycle, coal and biomass-fueled generators during Independent System Operator (ISO) dispatch control. Where is the pump operating? Which pump should take overhaul priority? These are certainly valid questions regarding asset availability, reliability and the associated financial consequences of “abnormal operation.”
Where Is the Pump Operating?
In the following example, one boiler feedwater pump (BFP) was selected from a group of eight where proactive field performance testing was accomplished. Performance testing was employed to provide the owner/operator with quantifiable pump condition data to aid in prioritizing unit overhaul schedules. This generation facility is configured with six separate combined-cycle units employing 12 BFPs. The example pump is one of eight axial-split, multistage, ring-section pumps. At the time of field performance testing, gross facility generation was limited by ISO dispatch to 60 percent of full generator/heat recovery steam generator (HRSG) load.
Which Pump Should Take Overhaul Priority?
Image 2 considers the same group of eight pumps as considered in the first example. By prioritizing time-based overhaul scheduling founded on actual unit performance, the owner/operator can maximize unit reliability and availability.
