Focus on O&M

  • Laser Hole-Shaping Improves Combustion Turbine Efficiency

    Laser shaping technology has evolved from a two-step process into a single process that drills and shapes holes through a TBC, bond coat, and airfoil base metal to create a finished product.

  • Deciphering Desuperheater Failures

    The "combined" portion of a combined-cycle plant is the heat-recovery steam generator (HRSG) that generates high-pressure and high-temperature steam and the steam turbine generator that expands the steam to produce electricity. Integrating the HRSG and steam turbine with the combustion turbine is a key challenge for plant designers, as each system has differing operating profiles, operational constraints, and design requirements.

  • Competitive Maintenance Strategies, Part II

    Nearly every combined-cycle operator recognizes that cycling reduces the life expectancy of hot-gas-path components in combustion turbines. Often overlooked, however, is that the same phenomenon affects the heat-recovery steam generator (HRSG).

  • Competitive Maintenance Strategies

    Many consultants are prospering today by creating "new" maintenance strategies. What they’re really creating is new buzzwords.

  • Restraining Torsional Vibration

    All rotating equipment power trains found in a power plant have some amount of vibration, usually caused by mechanical unbalance of the rotating system, shaft misalignment, or weakness in the bearing support.

  • Can Your Boiler Feed Pump Handle a Deaerator Pressure Transient?

    In a typical steam power plant, the boiler feedwater (BFW) pump takes suction from the deaerator (DA) and discharges high-pressure water to the boiler through the feedwater heaters. During normal operation, the DA is supplied with steam turbine extraction steam to mix with and heat the feedwater.

  • Widespread Voltage Collapse Demonstrates the Importance of Generator Acceptance Testing

    A September 2005 power outage that affected two million people in the California Southland was initiated when workers cut live electrical wires after consulting erroneous design drawings, but it was exacerbated by a number of extant problems with local generation and protection configurations.

  • Replacing an HP/IP Rotor

    Today’s power plant owners face many challenges, including the aging and degradation of equipment. Steam turbines at times may be condemned due to operating inefficiency or rising vibration levels. In such cases the options may be few because the turbine may require a full or partial rotor section replacement. The good news is that a rotor section replacement can be performed in a relatively short time, depending upon the original rotor configuration. Here’s one example.

  • Sealing Transformer Oil and SF6 Leaks Quickly and Effectively

    Transformers, which are prone to leaking, are an excellent example of where using the right materials and techniques can quickly reduce cleanup costs and potential environmental damage from a fluid leak. Transformer leaks are most commonly caused by degrading cork gaskets or holes in the radiator fins or the steel tank. Often these leaks are slow drips, but occasionally a catastrophic leak will occur, spilling hundreds of gallons of mineral oil into the environment and causing the transformer to short-circuit, causing further health and safety concerns. These dangers, coupled with transformers’ isolated locations, make inspection, repair, and maintenance a major challenge.

  • When to Use an Oil Skimmer

    Oil skimmers are very effective in removing oil from wastewater before discharge but are also perhaps the most efficient and economical approach.