Making Old Ideas New Again
NETL, the National Energy Technical Laboratory, says that coal is where all of the North American energy resides. According to Tom Snowdon, former Houston Lighting and Power plant manager, and now power industry consultant for Emerson Process Management's Power and Water Solutions business, it's time to look at how to modernize coal fired power plants, and produce new, optimized plants from scratch.
The way to do this, he said, "is to establish automation design criteria that address key design objectives." He noted that automated intelligence, and streamlining and integrating the plant with a plantwide architecture are key ingredients. Optimizing project execution is the other big part of the puzzle.
"It's all about enabling plant personnel to deliver optimal results," Snowdon said. "We have to be able to deliver economic benefits for the next thirty to fifty years."
The timeline is critical, too, according to Snowdon. "If we start planning a new plant now, we will be in operation five years from now. We need to plan based on the issues we know affect design: regulations, market forces, new technologies and especially the loss of institutional knowledge from our aging workforce."
Plants were traditionally built standalone, and then connected to the enterprise when generation fleets were separated from marketing in the 1990s. The idea, he said, "for new plants is to build a much larger pipe directly from the plant to headquarters, with streamlined processes, optimized resources, and improved reliability."
Design objectives have changed, too. Now plants need to be designed forward, so that they take advantage of the new and emerging applications and technology like smart field devices, fieldbus, predictive intelligence, advanced process control, wireless, and cyber security.
We need, he said, "to leverage for improved profitability. This includes optimization across the enterprise, human resources and operator skillsets, work processes, and technology deployment." This leads to real, bottom line benefits, he went on. "These benefits include decreased project cost and risk, increased reliability, reduced O&M costs, and either reduced staffing or better optimized use of the remaining manpower after our older workforce retires."
The key component is an optimized integrated architecture where the fleet is connected to the ESC (engineering and simulation center), the OC (operations center) and the MDC (monitoring, maintenance and diagnostics center) through functionally based automation intelligence in real time. Fieldbus, Snowden noted, "has become the standard for process automation, with a long list of benefits: reduced number of wires and marshalling panels; reduced number of power supplies and cabinets; reduced size of equipment rooms; remote configuration of devices; more information available for operations; increased accuracy of measurements; increased sophistication and flexibility of instrumentation; and increased uptime due to less equipment, better self diagnostics, and remote diagnostics."
In addition, automated intelligence can provide predictive intelligence with automated advanced control, and operator guidelines so that operators who now and going forward are not as savvy as their predecessors can be helped to troubleshoot and repair problems quickly and economically.
For the plant, this can provide day-ahead product scheduling, help fine tune unit startup and shutdown and help balance load changes between operating ranges. It can even automate makeup demin water and regeneration cycles.
"When I was a plant manager," Snowdon quipped, "I used to wonder why a demin water plant could not be automated. It used to hurt to have to pay overtime and double overtime to schedule an operator out there just to make sure we had startup water."
Fuel blending for best combustion is also practical with automated intelligence, as is controlling the tradeoff between Nox and heat rate to optimize combustion and profit from the plant. "Now we can find what I call the sweet spot to operate in," Snowdon said.
A fully integrated architecture also provides automated and more importantly, accurate recording and reporting of unit startup and shutdown costs, controlling power, fuel, time, and consistency. "We can optimize and limit fuel usage," Snowdon said."And we can report properly to NERC CADS, DOE EIA, local and state governments"¦and above all, the control logs will always match the dispatch logs!"