Archive: O&M

Focus on O&M (November 2007)

The NERC auditors are coming / Winning encore for on-line pH monitoring / Using baloons as temporary barriers / How data logging can cut power bills

The Coal Patrol: Demand Growth — and Reliability — Are Still Supply-Limited

While noting marginal improvements since last year, America’s power reliability watchdog recently warned that the nation’s growing thirst for electricity will still far exceed planned increases in generation capacity over the next 10 years, and that reserve margins could dip below optimal levels within two or three years in California, the Rocky Mountain states, New […]

Tech Notes: Intelligent Sootblowing Needed to Keep Uprated Units Clean

The National Coal Council estimates that 40,000 MW of additional generating capacity is available to existing U.S. coal-fired plants simply by making efficiency improvements. Because decreases in production costs go straight to a plant’s bottom line, efficiency projects usually have short payback periods, especially if implemented in concert with mandatory environmental upgrades. One often-overlooked consequence […]

Focus on O&M (October 2007)

Why bypass desuperheaters fail; DSSP, CAD, and fast casting salvage nearly totaled pump; Seals of approval; Making gas turbine plants quieter

Focus on O&M (September 2007)

Replace pumps, cut repair bills / New bolts show their stress level / Up a certain creek, without a filter / Hang up those cables and hoses

Mercury Control: Capturing Mercury in Wet Scrubbers: Part II

In Part I of this two-part report ( COAL POWER, July/August 2007, p. 22), we introduced the integrated R&D effort by the U.S. Department of Energy’s National Energy Technology Laboratory (DOE/NETL) to improve understanding of the mechanisms of mercury (Hg) capture and retention in flue gas desulfurization (FGD) systems and the fate of Hg in […]

The Coal Patrol: Mine Safety Deserves More Than Lip Service

Every step forward in underground U.S. mine safety in the 20th and 21st centuries has been on the backs of mangled and dead coal miners. That grisly observation is unassailable. Following the August tragedy at the Crandall Canyon mine in Utah that killed six miners and three would-be rescuers, the federal Mine Safety and Health […]

Plant Economics: The Impact of Shortages on FGD Prices

Since ratification of the Clean Air Act (CAA) in 1970, U.S. utilities have made steady efforts to install pollution control equipment to curb power plant stack emissions. The CAA Amendments of 1990 raised concerns at the time about the industry’s ability to install a large number of flue gas desulfurization (FGD) systems, or scrubbers, in […]

Use predictive techniques to guide your mercury compliance strategy

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.

Finding and fixing leakage within combined HP-IP steam turbines: Part II

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.