EthosEnergy completes innovative boiler feed pump turbine repairs
EthosEnergy has completed a full inspection, repairs, testing, and reassembly of a Westinghouse boiler feed pump turbine for a US power station, bringing the unit back to full load.
Coyote Station, located near Beulah, North Dakota, is operated by Otter Tail Power Co. headquartered in Fergus Falls, Minnesota.
The Coyote Station boiler feed pump turbine experienced an overspeed event that resulted in a failure of the steam path and severe damage to the casing and bearing brackets.
EthosEnergy provided an alternative solution to replace the steam path with a modern design that has enhanced thermodynamic performance and ease of maintenance, which allowed Coyote Station to get back to full load sooner than if they were to purchase a new turbine assembly.
Brad Zimmerman, Coyote Station plant manager, said: "When we awarded EthosEnergy the work, we knew their solution had an added value element, in that they wouldn't just repair the unit but improve performance and efficiency through use of modern manufacturing techniques.
“The efficiency improvement was projected to be around 3%. However, we are now getting closer to 7-8% improvement out of the boiler feed pump turbine."
EthosEnergy's solution was to manufacture a new modern designed rotor, blades, diaphragms, and repairing the nozzles, valves, and bearings.
In addition a full casing overhaul was employed to straighten and realign back to specification.
Following shop repairs, the boiler feed pump turbine was returned to the Coyote Station where EthosEnergy provided full non-destructive testing, sole plate regrouting, alignment, and reassembly.