Owner/operator: Tennessee Valley Authority
When TVA’s Bull Run Fossil Plant was erected in the mid-1960s, it could boast of having the largest boiler in the U.S., and the plant has enjoyed a long, enviable efficiency track record. Today the public judges coal plants by their emissions. Now that it’s been outfitted with the most advanced air quality control systems, including the latest flue gas desulfurization system design, Bull Run scores a perfect "10" in both categories.
The Bull Run Fossil Plant, located on the Clinch River near Oak Ridge, Tenn., is unique in that it is the only single-unit, coal-fired plant on the Tennessee Valley Authority (TVA) power system. The 920-MW plant uses a unique supercritical, once-through boiler technology with twin, divided-wall furnace boiler formed with about 300 miles of furnace, superheater, reheater, and economizer tubing. When the plant entered commercial service in 1967, its boiler was the largest ever erected in the U.S. (Figure 1)
1. One of a kind. TVA’s Bull Run Fossil Plant, located on the Clinch River near Oak Ridge, Tenn., after completion of the flue gas desulfurization project. A new 500-foot stack replaced the old 800-foot stack. Courtesy: URS Washington Division
There are benefits to being unique: Bull Run has been consistently recognized as one of the most efficient steam plants in the U.S.
Time to Add a Scrubber
Bull Run burns either medium- or low-sulfur coals from Central Appalachia. TVA contracted with Advatech for the installation of a wet flue gas desulfurization (FGD) system, or scrubber, on the plant in 2005, after installation of a selective catalytic reduction (SCR) unit to reduce NOx emissions.
The Bull Run FGD Project — which added the eighth scrubber to the TVA system and was the second to use Advatech’s double contact flow scrubber (DCFS) technology — is part of TVA’s $5.7 billion emissions upgrade program. Of that total, $1.5 billion has been allocated to five scrubbers at four TVA plants. At last count, TVA had invested $450 million for its SCR and FGD system upgrades at Bull Run alone. TVA plans for two Advatech scrubbers to begin service at the Kingston Fossil Plant this year and next.
TVA elected to package the complete Bull Run project scope — engineer, procure, construct (EPC) — including balance-of-plant and original equipment manufacturer FGD technology, into one contract. TVA engineers developed the conceptual design and defined the entire project scope of work and emissions guarantees, including a very aggressive 98% sulfur removal efficiency (see table). Advatech — a URS/Mitsubishi Heavy Industries America joint venture — was selected as the EPC contractor in a multiple scrubber system purchase by TVA. The FGD technology was supplied by Mitsubishi Heavy Industries.
Bull Run Fossil Plant FGD Project specifications. Source: URS Washington Division
The EPC scope of supply included every aspect of the project: detailed engineering, procurement, construction, start-up and commissioning services; ductwork; absorber module; internal piping; nine recycle pumps; new 500-foot stack with a fiberglass-reinforced plastic liner (the old 800-foot stack remains in place); three forced oxidation compressors; three air rotary spargers that provide combined oxidation and slurry agitation; mist eliminators; redundant dry preground limestone unloading, storage, and feed systems; distributed control system for FGD and existing plant upgrade; electrical power distribution system (including transformers); and all foundation and building systems. The EPC contract did not include high-voltage electrical supply or construction of the gypsum storage facility.
The FGD project contract release date was April 19, 2005, and the system entered commercial operation on December 13, 2008.
Email
Comments
Print
Reuse
Comments (1)