Whether a power plant chooses an air-cooled condenser (ACC) because of siting issues, or because of changing environmental laws, the utilization of this dry cooling option has seen a dramatic level of growth over the past decade around the world. Like the steam surface condenser, the ACC is prone to tube fouling, albeit to the external finned tube surfaces instead of internal surfaces. This tube fouling can dramatically impact the performance of the ACC causing plant heat rate to suffer, increasing the consumption of fuel, increasing CO2 emissions and reducing megawatt output. In addition to fouling, ACC units are exposed to dramatic swings in ambient temperature. Units exposed to multiple freeze-thaw cycles each year often develop numerous points of inleakage into the vacuum boundary, also causing unit efficiency to suffer. Unlike the steam surface condenser, the ACC can be elevated at 60–75 feet in the air which poses considerable challenges to locating and repairing the sources of leaks.
This paper will examine the performance improvements realized by the Yellowstone Power Plant, located in Billings, Montana on their ACC unit after utilizing an innovative cleaning technology as well as the use of a new finned tube “sleeve” to repair leaking tubes.