Longview Power utilizes state-of-the-art technology to safely and economically produce reliable energy with exceptional environmental performance.
Longview’s technology includes: an advanced supercritical pulverized coal-fired boiler, a high efficiency turbine-generator, a cutting edge distributed control system and a full complement of Air Quality Control Systems (AQCS) that meet or exceed Best Available Control Technology (BACT).
Longview’s modern, clean coal technology design enables best-in-class energy and environmental performance with industry leading reliability. What makes Longview innovative and modern?
Advanced Supercritical Boiler
Amec Foster Wheeler supplied Longview with a first-of-a-kind once-thru, low-mass flux vertical tube Advanced Supercritical Boiler. This new class of supercritical boilers utilizes new metal alloys that allow the boiler to produce steam at higher temperatures and pressures than previously achievable. These technology advances operated by Longview’s highly skilled plant personnel, means higher efficiencies, greater reliability and a much cleaner environment.
In 2015 Longview replaced over 1,000 boilers tubes to repair initial design and materials issue. Improvements to the fuel/air controls now provide best-in-class combustion control (no slagging, better emissions control, improved reliability). The NOx controlling catalyst system was optimized, boiler circuitry was modified and perfected, and a simpler more robust bottom ash system was installed. The result – all initial tube leak issues have been resolved and the unit is setting new standards for reliability, efficiency and environmental performance.
Advanced Emissions Systems
Longview is a leader in environmental performance utilizing and optimizing best-in-class Air Quality Control Systems (AQCS) provided by Amec Foster Wheeler. Longview, by design, is more efficient in both producing affordable electric power and reducing emissions due to advanced, integrated pollution controls in the original design. Older legacy coal power plants with retrofitted pollution controls incur efficiency losses, while Longview’s AQCS equipment effectively and reliably remove all targeted pollutants without adversely affecting efficiency:
- Acid mists are controlled with a hydrated lime injection system
- >99% of particulate matter (“fly ash”) is removed by a Pulse Jet Fabric Filter (PJFF)
- Up to 99.5% removal of SO2 is accomplished by a Wet Flue Gas Desulfurization (WFGD) system
- NOx emissions are controlled by low NOx burners by overfire air and a Selective Catalytic Reduction system (SCR – akin to a car’s catalytic converter)
- CO2 emissions are the industry’s lowest achievable for coal plants due to Longview’s high fuel efficiency
Advanced Generator Technology
The business end of the Longview clean coal technology is the Siemens HMNN 770mw steam turbine and SGen6-3000w generator. This combination is one of the industry’s newest, most efficient means of converting high pressure/temperature steam into electric power.
Siemens Model # SGen6-3000W Generator
- Hydrogen and water cooled, improving heat transfer and reducing friction losses to achieve up to 99% operating efficiency
- Rated for 807MW/hr
Siemens HMNN 770 MW Turbine System
- Tandem compound arrangement
- Four turbine sections
- High, intermediate, two low pressure sections
- Attached directly via a single shaft to the generator
- Inlet steam conditions of 3600 psi, 1050f
- 5,027,000 lbs/hr of steam flow at valve wide open operation
Advanced Startup Capability
Coal is not the only fuel required for a coal-fired power plant. Secondary fuel is required for startup and for significant load changes. At Longview, natural gas from a local gas distribution company is used when available. However, the local gas company has limited capacity and must serve residential and key industrial users which, at times, take priority. Longview addressed this potential limitation by installing the world’s largest mobile LNG facility. This unique system provides Longview with full “inside-the-fence” startup reliability during peak winter seasons allowing Longview to meet PJM capacity performance requirements.
