O&M

By design, combined HP-IP turbines have a small amount of internal leakage from the high-pressure turbine to the intermediate-pressure turbine. As turbines age, the leakage increases considerably and becomes excessive, creating a heat rate penalty and possibly a reliability problem. Last month we explored the symptoms and causes of steam leakage within GE steam turbines and how to correct the problem. In Part II, we examine the same issues for Westinghouse and Allis-Chalmers turbines from both theoretical and practical angles.

Several states have mandated faster and/or deeper reductions in plant mercury emissions than those called for by the Clean Air Mercury Rule. Unfortunately, differences between plants make accurate evaluation of control options difficult. In most cases, even statistically based Hg emission models don’t pass muster because they don’t account for the dynamic chemical behavior of Hg species in gas cleaning systems. This article describes one system evaluation tool that has been validated using Hg field test data from 50 full-scale flue gas cleaning systems. It is already being used by TVA and other utilities.

Have you bought electrostatic or agglomeration equipment to rid your turbine oil of varnish deposits, but its varnish potential rating failed to improve? Or, after an initial drop, has the varnish potential returned to its previous level? Even worse, have you had recurring valve sticking problems after making a sizeable investment to "solve" this problem? Welcome to the world of soluble varnish caused by autodegradation. Read the unvarnished truth about varnish and how to get rid of it for good.

Stop valves from leaking money / Integrating plant and equipment models / Pricing priceless knowledge

MidAmerican Energy Co. and its project partners are convinced that supercritical coal-firing technology’s inherently higher efficiency and lower CO₂ emissions no longer come with a price: reduced reliability. Their Walter Scott, Jr. Energy Center Unit 4, the first major new supercritical plant in the U.S. in more than 15 years, is POWER’s 2007 Plant of the Year.

Hydro-demolition speeds reactor dome entry;
Tips for keeping your unit stable;
Air makes heavy move a breeze

When injuries or accidents occur, the employer ultimately loses on two counts: increased medical costs and employee absences. A policy of "safety, compliance, and then production" is more than just good business; it’s also good stewardship of the health and safety of employees who deserve no less.

The 1990 amendments to the Clean Air Act require coal-fired power plants to reduce their emissions of the pollutant SO2. To do so, many have switched to, or are considering switching to, Powder River Basin (PRB) coal. Unfortunately, PRB coal has a tendency to leave excessive and tenacious deposits on boiler heat-exchange surfaces. Complicating the problem, the distribution of the deposits is far from uniform.

The U.S. Department of Energy (DOE) and Great River Energy are testing a new coal-drying technology that could dramatically reduce the emissions of lignite-burning power plants. The project was selected for funding during Round I of the DOE’s Clean Coal Power Initiative (CCPI), a series of competitions to demonstrate a range of promising clean-coal technologies. […]

Lawrence Energy Center (LEC) proudly hosted about 60 representatives of the Powder River Basin Coal Users’ Group (PRBCUG) at its July 24th open house, luncheon, and plant tour. LEC was named the PRBCUG’s 2007 Plant of the Year at this year’s ELECTRIC POWER Conference and Exhibition in Chicago, May 1 – 3. Traditionally, the winning […]