After a year and a half, two new boilers at the Yarborough Steam Plant, located on North Campus, are up running and should provide energy to the campus community more efficiently.
An 18-month project to upgrade the boilers at the Yarborough Drive Steam Plant is now complete, which should result in a 14 percent improvement in energy efficiency. Plant engineers replaced two 60-year-old, 50,000-pound-per-hour boilers with two new 100,000-pound-per-hour boilers, according to the NCSU Bulletin.
“Sustainability at N.C. State is about helping make the university leaner, smarter and stronger,” said Carla Davis, communication coordinator for the University Sustainability Office. “These boiler upgrades certainly accomplish this by increasing efficiency and improving campus energy reliability.”
The Yarborough Plant works in tandem with the Cates Utility Plant to provide steam for heat and chilled water for cooling to both Main and Central campuses, according to Bill Ferrell, a plant engineer at the Yarborough facility. The Yarborough upgrade was the last phase in a $61 million energy performance contract, which also added cogeneration technology to the Cates Plant in 2012.
“Simply put, cogeneration is where we take incoming fuel source—natural gas—convert it into electricity for the campus and use the waste heat from a gas turbine to produce free steam to heat the campus,” Ferrell said.
Instead of letting the exhaust heat dissipate into thin air, cogeneration technology captures this heat and uses it to generate steam. This process is called “combined heat and power,” Ferrell said.
In addition to the new technology, the updated Yarborough Plant boilers will run on a different type of fuel oil that burns cleaner than its predecessor. This fuel oil is used as a backup fuel supply in case the natural gas supply is reduced by suppliers to meet higher demands of other customers.
According to the Bulletin, the renovation is expected to earn LEED Silver certification from the U.S. Green Building Council, which recognizes sustainability through processes such as the recycling rate of steel and other demolition debris, efficiency improvements and the use of sustainable building materials.
In November, the Yarborough Plant emitted black smoke during the instillation process of the new boilers.
According to Alan Daeke, director of Utilities and Engineering Services at N.C. State, the smoke appeared when Yarborough Plant operators used oil to fuel the new boiler.
“Natural gas is the primary fuel source and the number two fuel, oil, serves as a backup source,” Daeke said in November. “The new boiler had just started on fuel oil and the burner management control system needed adjustment.”
According to Daeke, the problem was corrected shortly after it occurred, and the plant is staffed 24 hours a day, seven days a week with qualified staff to ensure that potentially harmful problems do not go unnoticed.
“Black smoke can occur when using fuel oil and the fuel-to-air ratio needs to be adjusted,” Daeke said. “This has been corrected, and the campus community should not be worried about this situation.”
Ferrell said another steam plant upgrade is planned for Centennial Campus.
“We are currently adding another 2,000-ton chiller to the Centennial Campus Utility Plant for additional capacity and redundancy for the Centennial Campus chilled water system,” Ferrell said.
The Yarborough Plant is run by the Utilities and Engineering Services group. According to Ferrell, the primary purpose of the UES is to provide thermal and electrical utilities to all campuses.
“These upgrades are done in an effort to provide consistent and reliable utility services to the entire campus community,” Ferrell said.
