When you receive a shipment, you don’t wait weeks to see whether you got what you paid for — do you? J.M. Stuart Generating Station doesn’t, but it used to. Since coming on-line in the early 1970s, the big plant, on the Ohio River near Aberdeen, Ohio, mechanically sampled coal shipments as they reached the […]
Historically, cyclone-fired boilers have been characterized as big emitters of NOx due to the very high temperatures in their primary combustion zone. Uncontrolled levels from 0.8 to 1.9 lb/mmBtu have been typical. The design of cyclone-fired units makes them impossible to retrofit with standard low-NOx burners. Prior to 1997, the conventional wisdom was that cyclone […]
Layering NOx control technologies can reduce a coal-fired unit’s NOx emissions to levels achievable by selective catalytic reduction alone. Advanced Combustion Technology Inc. (ACT) (www.advancedcombustion.net) has demonstrated that using several in combination can cut emissions from boilers firing eastern bituminous coal or No. 6 oil to less than 0.15 lb/mmBtu. The following two case studies […]
To borrow shamelessly from Charles Dickens, one of my favorite authors, for coal in 2006, "It was the best of times, it was the worst of times." No Escape The year began in horror. On January 2, most likely a result of a severe lightning strike, methane gas in the International Coal Group’s Sago Mine […]
Safeguarding coal-handling assets;
Giant wind turbine hard to bear
In 2005, Xcel Energy fully implemented its unique Utility Innovations initiative to encourage its IT vendors to work together. One pilot project completed under the UI umbrella confirmed that tighter integration of predictive and analytical systems and data can optimize preventive maintenance intervals, reducing costs and downtime while increasing profits and productivity.
The O&M staff of AES Westover Station wisely took a holistic approach to optimizing combustion within Unit 8’s boiler in order to reduce its NOx emissions while maintaining acceptable levels of carbon-in-ash content. The results of major modifications—centered on the addition of a fan-boosted overfire air system—were a 60% reduction in NOx levels, improved unit reliability, and a project payback period measured in months rather than years. As this project proved, the whole is more than the sum of its parts.
Upgrading to digital–twice / Lower-cost turbine monitoring / Pros and cons of remote process control / Nuts about Superbolt
Large T&D-sized transformers age as quickly as generating assets do. But preventing transformers from failing is difficult because they have no moving parts and are sealed up. Tracking the concentrations of certain gases—the more, the better—that are dissolved in a unit’s insulating oil is a proven way of detecting damage before it causes a costly problem.
The visible consequences of sulfuric acid aerosol emissions—opaque stack emissions called “blue plumes”—are merely the tip of an iceberg. In sufficient concentration, SO3 also can increase corrosion and fouling of equipment and components downstream of the furnace while decreasing their efficiency and penalizing overall plant heat rate.