Applying Advanced Process Control Principles to Power Generation

  • March 11, 2009
  • Feature
By Carl Hosier, senior marketing leader, power generationHoneywell Process SolutionsIn the manufacturing world, the word “retrofit” many times is feared to mean “lost production.” In other words, plants – or at least parts of plants – must be shut down for equipment to be upgraded. And idle machinery means less production.Perhaps nowhere is this concept feared more than in the power-generation industry, where scheduling a forced outage means less electricity, steam or heat for the production plant. Nevertheless, equipment retrofit is largely becoming a necessary part of the job because power-generation companies across the world are being tasked to meet the needs of an expanding global industrial base while keeping a cap on greenhouse gas (GHG) emissions, all with aging infrastructures. It’s easy to see how complicated the daily lives of these generators can become.Taking a cue from the world of advanced process control, however, could prove to be a viable alternative for meeting government regulations on GHG emissions while increasing power, heat and steam output without a major process overhaul. Specifically, many manufacturing facilities in industries such as chemicals, refining and pulp and paper have taken to integrating plant subsystems with their distributed control systems (DCS) to maximize productivity and improve overall efficiency. Applying this same concept to the world of power generation with the goal of reducing GHG emissions could very well help electricity and steam generators streamline production in a way that makes sense to both their pocketbooks and the regulators. Advancing the ProcessAs the utilization of current energy generation equipment is increased, so is the creation of GHG emissions. To combat this problem and address the standards set by global governments to reduce nitrogen oxide (NOx) emissions, power companies are turning to advanced energy solutions technology. NOx is a by-product of the combustion process and is increased the hotter the flame temperature used in the process. When combined with volatile organic compounds, NOx can create smog or ground-level ozone pollution in hot stagnant weather – causing respiratory problems in humans. To meet these emerging GHG regulations, power generation companies must retrofit their boilers, install new boilers or enhance production processes to drive further efficiencies.Retrofitting old boilers or installing new ones, though, can be problematic. This is because it is impractical to shut down an entire production facility when the demand for electricity continues to grow. By scheduling a forced outage, an entire power generation facility will bring production to a halt for its industrial customers –not an ideal scenario for the power companies or the global economy. In all types of industrial power operations, there are a number of relatively fixed factors affecting overall plant operations requiring effective optimization measures. These include boiler design, cooling water conditions, burner type, design steam conditions and environmental controls that capture and remove pollutants. By optimizing the operation of a plant’s subsystems taking into consideration these multiple parameters can improve the efficiency and utilization of equipment, along with addressing environmental standards. This can be done with software instead of having to replace or retrofit expensive capital equipment.This advanced energy efficiency software takes a cue from the world of advanced process control and optimization by integrating functions ranging from combustion control and steam pressure control, to plant monitoring, plant performance optimization and tie-line control. The core of this approach involves integrating the technology with the plant’s existing DCS architecture, including field instruments, SCADA, plant historians and other advanced control functions such as simulation software and advanced process control and optimization applications. With this type of advanced energy solutions, power companies are able to centralize the control functions of their plants on this modular software platform. Within the central operating structure plant operators will have the flexibility to:
  • Monitor and control the flame temperature during the combustion process, reducing fuel use to achieve the same energy production numbers, while helping to reduce GHG emissions to regulatory levels. This ultimately results in improved combustion control and a system that improves thermal efficiency of individual boilers.
  • Achieve continuous balance between produced and consumed steam. This master pressure control approach controls total heat input into boilers, as well as total steam flow into each header.
  • Optimize plant performance through economic load allocation for boilers. This improves the utilization of steam for electricity generation, process and/or heating needs. It also expands boiler house efficiency and flexibility by distributing total heat input amongst boilers and maintains a wide steam production range.
  • Stabilize the steam pressure and prevent boiler and turbine outages guaranteeing continuous balance between produced and consumed steam. This improves boiler efficiency, increases boiler life and improves generation efficiency.
  • Better monitor plant performance through a toolkit to improve the visibility of production operations by monitoring all key performance indicators (KPIs). Knowledge of KPIs allows plant personnel to address problems before they occur, and improves asset reliability.
  • Monitor the power-generation process in real-time, along with external contractual commitments and internal consumption rates. Using this tie-in control also manages the power-generation needs to meet anticipated user demand for electricity.Increased Visibility = Better DecisionsThe main premise behind system integration and advanced process control is to provide plant or mill personnel the most relevant information to help them make decisions that ultimately keep the plant running safely, reliably, efficiently, and within environmental constraints. In power generation, using advanced energy control application solutions not only streamlines operations – it increases visibility for the operator across all subsystems. By giving plant operators the tools to accurately monitor the power generation process in real-time, they can quickly make informed decisions that significantly impact bottom-line performance.Advanced energy solutions improve power generation efficiency at the boiler level and across the entire plant, so power companies no longer need to consider executing a major equipment refurbishment to reduce operating costs. The software applications provide industrial power generation facilities worldwide with a low-cost, high return alternative to expensive boiler retrofits to improve operational efficiency, while reducing GHG emissions, to meet tomorrow’s industrial manufacturing’s electricity needs. Learn More

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