2013 Technical Seminar Highlights Power Industry Changes and Challenges

Previous Next

Another recurring theme was the impact natural gas has had on the power industry. Despite ongoing concerns about continuing reliability and low cost, many new power generation facilities will operate with natural gas. In his keynote address, Kevin Geraghty, vice president of power generation, NV Energy, said, “Watch what happens with natural gas. If it stays low in price, is really abundant and can be recovered in an environmentally acceptable way, it will take a larger share of power production. If it returns to its historical volatility, watch out. We have to have a mix of power generation sources, including renewable.”

David Gandy, program manager for Technology Innovation at EPRI, echoed the importance of a diversified power system. “We can’t go with just any one or two of the technologies. It will take the entire portfolio if we want to remain competitive. And remember, the existing infrastructure was built over several decades. It takes a long time to transform that kind of system.” Gandy continued, noting that “the fact that there is a lack of a coherent energy policy in the U.S. creates an issue in planning. The fact that environmental regulations, climate policy and renewable energy standards are far from set means it is difficult to set a course.”

In order to have a fully diversified energy portfolio, advanced materials technologies must be an integral part of it. “We are working on advancing ultra-supercritical coal technologies to improve efficiencies and reduce emissions. When you go from 3300 to 5500 PSI, and increase the temperature to 1400°F, you get an increase in overall efficiency from 41.5% to 46% or 47%, so there are substantial increases in efficiency simply as a result of increasing pressure and the overall operating temperature. That requires new materials, though, to get to that 1400-degree range.”

Gandy summarized the situation. “Existing generation will take time and significant investment to replace and upgrade. Advances in technologies will require new alloys, improved materials processes and re-investment in forging capabilities.”

On the Technical Side

Problems arose when those workhorse plants had to be turned down, then back up. They were designed to run continuously. And when the plant is lower down in dispatch order as it ages, budgets get tighter, resulting in more problems. “If forced to run at reduced load, there can be dramatic effects on the unit’s heat rate and cycle life of its valves and actuation. It’s like your old second car. First you won’t wax it any more, and then you use cheaper oil. You just do what you have to in order to get it by.”

Codes and Specifications

Neil Kalsi, senior specialist and project manager, Kalsi Engineering, covered nuclear power-operated valve qualification and life extension. He also itemized nuclear design and construction requirements, noting the challenges for new entrants in the nuclear game. They include the expense of implementing a nuclear program and dealing with the Nuclear Regulatory Commission operating environment and related history. “A fundamental shift in thinking and new learning is required when dealing with this,” he said.

Velan’s Paul Major, manager of nuclear design, discussed codes and specifications from the point of view of a North American valve manufacturer supplying to the North American industry, how codes, standards and specifications influence valve design in the power industry. He stressed that, although there are requirements for valves in various sections of the codes, they do not drive the design of the valves. While the codes refer to other standards for valve design and construction requirements, there have not been any significant changes over the years that have forced large changes to the design of a given valve.

Welding

Casting Challenges

Casting quality was brought into sharp focus during a presentation by Ken Juncewicz, senior principal engineer, GE Energy. Juncewicz shared an experience Progress Energy had with large bore C12A valves that had been ordered for HP and HRH steam lines. During routine correspondence with the design company, the company noticed that numerous base metal repairs had been performed on the valve bodies at the valve manufacturer. When Progress requested weld documentation, including filler metal chemistries, PWHT charts and hardness data, serious problems emerged.

The complex process of casting high-quality C12A valves was covered from a supplier’s point of view by Elaine Thomas, director of metallurgy, Bradken Tacoma (Atlas). Thomas enumerated the various stages involved in the process, from molding through testing of the metal to be used in the product, to inspection of the finished product. She also addressed new ASME requirements.

Producing More with Less

Electric Actuation

In their presentation on specifying electric actuation for the power industry, Bill Breitmayer and Justin Ledger of AUMA Actuators itemized the valves and electric actuators typically used in power plants. Stressing that specifying the proper actuator features is important, they urged consideration of the application, the valve characteristics, what type of motor controls are required, the environment, and what is the primary and control voltage.

The VMA Technical Seminar & Exhibits is an annual event open to the industry. Information about the 2014 meeting will be posted on VMA.org as soon as it is available.

Kate Kunkel is senior editor of VALVE Magazine. Reach her at kkunkel@vma.org.