Features - October 2011
NETL's AVESTAR™ Center-Simulating the Next Generation of Clean Coal Technology
Imagine you could learn to fly a space shuttle or rebuild your car's transmission without touching a piece of equipment or getting your hands dirty. Now, apply this concept to learning how to operate a state-of-the-art electricity-producing power plant capable of carbon dioxide (CO2) capture. That's what the Advanced Virtual Energy SimulationTraining and Research (AVESTAR) Center is designed to do. AVESTAR was established as part of the Department of Energy's initiative to advance new clean coal technology for power generation. With additional support from the NETL-Regional University Alliance (NETL-RUA), the AVESTAR Center will focus primarily on providing simulation-based training for process engineers and energy plant operators, starting with the safe and effective management of an integrated gasification combined cycle (IGCC) power plant. Under the direction of Dr. Stephen E. Zitney, NETL's Process and Dynamic Systems Research Group planned, developed, tested, and deployed an IGCC dynamic simulator in collaboration with energy experts from West Virginia University, Fossil Consulting Services, Invensys Operations Management, Enginomix, the Electric Power Research Institute, and several leading energy companies.
|The AVESTAR Center is focused on developing a workforce well-prepared to effectively operate, control, and manage the next-generation of high-efficiency IGCC power plants.
AVESTAR is designed to provide state-of-the-art, highly realistic, dynamic simulator training in the operation of an IGCC plant, including normal and faulted operations, as well as plant start-up, shutdown, and power demand load changes. The simulator also allows for testing of different types of fuel sources, such as petcoke and biomass, as well as co-firing fuel mixtures. The IGCC simulator builds on, and reaches beyond, conventional power plant simulators to merge, for the first time, a “gasification with CO2 capture” process simulator with a “combined-cycle” power simulator. By providing a comprehensive IGCC operator training system, AVESTAR aims to develop a workforce well prepared to operate, control, and manage commercial-scale gasification-based power plants with CO2 capture The Center also promotes NETL's outreach mission by offering hands-on simulator training and education to researchers and university students.
Balancing America's Energy Supply and Demand with Environmental Responsibility
Today most of the energy consumed in the United States comes from coal, petroleum, and natural gas. Fossil fuel sources account for approximately 80 percent of national and international energy production, and coal-fired power plants account for greater than half of the electricity generated in the United States. With increasing global energy demands, coal is expected to play a dominant role in meeting future energy needs.
Why do we use coal? The answer is fairly simple, considering that the United States is home to the largest accessible reserves of coal in the world, accounting for approximately one quarter of the world's coal deposits. Coal is the largest domestically produced source of energy. While estimates vary, it has been projected that the United States has enough coal reserves to last another 200 years. Availability and accessibility, coupled with relatively low cost-particularly in light of other energy sources-are the primary reasons why consumers in the United States benefit from some of the lowest electricity rates in the world.
However, there are trade-offs for inexpensive energy. The use of coal produces emissions that can impact our environment. For example, coal combustion is associated with increased sulfur dioxide, nitrogen oxide, and mercury. Coal utilization also emits CO2, a greenhouse gas that has been prominent in the news due to its association with global warming. Significant advances have been made to reduce environmental contaminates resulting in coal usage, and ambitious efforts are underway to advance new technologies to burn coal more efficiently while minimizing environmental impact. NETL and its partners have undertaken a variety of strategic initiatives to explore ways of capturing and permanently storing CO2 as a way to reduce CO2 release into the atmosphere.
The Role of AVESTAR in Accelerating Clean Coal Technology
Relative to power efficiency and environmental conservation, gasification technology represents the future for coal-derived electricity. Simply defined, gasification is a process that uses heat, pressure, and steam to convert coal into a synthesis gas (also known as syngas), which is mainly hydrogen and carbon monoxide. The syngas is cleaned to remove impurities and sent to a gas turbine where it will undergo combustion to produce electricity. The hot exhaust gas from the gas turbine is used to generate steam, which is then fed to a steam turbine to produce additional electricity. This process is known as IGCC because a coal-fired gasification process is integrated with a combined cycle system that produces electricity from both a gas turbine and a steam turbine driven by the gas turbine's exhaust.
|Human-machine interface display screens provide the realistic “look and feel” of an IGCC plant operator control room.
Compared to traditional power plants, IGCC offers many advantages, including increased power plant efficiency, resulting in lower-cost electricity. Because gasification occurs at higher temperature and pressure, with limited oxygen, environmental contaminants are easier to remove from the flue gas stream. The system also makes it possible to concentrate CO2, providing for more efficient removal. Aside from coal, a wide range of carbon-containing materials, such as petroleum coke and biomass, can be used to produce syngas. In addition to being used for electricity, syngas can be converted to other end products, such as specialty chemicals, clean hydrogen, and transportation fuels. Coal gasification electric power plants are now commercially operational in the United States and other nations, and energy experts predict that this process represents the future of clean coal technology. AVESTAR will be instrumental in providing the training required to operate these new power plants.
What Makes AVESTAR Work?
Flight simulators that train pilots create realistic environments using full cockpit mock-ups and computer-based software. These two pieces work together to replicate what really happens when the pilot flies the plane. When the pilot adjusts the thrust, the simulation software changes the instrument readings and cockpit screen to create realistic views of flight scenarios, including take off, landing, and the occasional mishap, all in a safe training environment.
Today, the energy industry is also using training simulators to teach plant operators how to safely start up, control, and shut down their processes in a risk-free environment. For AVESTAR, Invensys Operations Management has worked with NETL to develop a virtual “cockpit” (the plant control room) and “flight simulator” (the plant real-time dynamic model) to create an environment where trainees can be taught how to operate clean-coal IGCC power plants with carbon capture.
|The IGCC dynamic simulator is a full-scope operating training system for normal and faulted operations (in this case, an animated gas leak) as well as plant start-up and shutdown. Operators can interact with the system in real time, simulating real-world power plant conditions.
Invensys's DYNSIM® software combines heat and material balances, thermodynamics, and reaction chemistry to create high-fidelity dynamic process models that accurately predict what will happen when operators perform certain actions from inside the plant's control room. The company's InTouchTM software, a human-machine interface, recreates the look and feel of the control room to complete the training environment. For example, the integrated DYNSIM and InTouch system allows an operator to open a plant valve, initiating the flow of coal slurry into the gasifier vessel. The DYNSIM software predicts the rate at which the coal will react with oxygen from the air separation unit and provides readings on gasifier conditions to the plant operator, who is working in a simulated control room using InTouch. Viewing the information provided via DYNSIM, the operator knows when the gasifier is at full load so he or she can maintain safe operation and avoid gasifier trip conditions.
DYNSIM and InTouch can model every operating condition, including emergency and hazard scenarios, to provide complete training in a risk-free environment. The training platform can also provide simulations that assist in the design, construction, and performance improvement of IGCC plants. Designers can run and validate an entire control strategy before the plant is even built. And once the plant is up and running, the training solution can be integrated with the control system for continuous operation and refinement based on real-world data.
Build it and They will Come
|Simulation showing the internal components and vapor flow of a distillation column from the IGCC immersive training system.
It's an overused cliché, but that's exactly what the AVESTAR team is banking on. The Center offers a combination of classroom and dynamic simulator instruction to provide hands-on experience operating a commercial-scale energy plant. The instructional team can work directly with clients to analyze their needs and goals to design customized training courses.
Based on attendance at the inaugural demonstration sessions, AVESTAR is getting off to a good start. More than 40 engineers and researchers from NETL, URS Corporation, and NETL-RUA provided valuable feedback on the simulator and facilities. The Center also recently offered its first simulator-based training course, IGCC Orientation for Engineers and Managers, providing trainees from the power industry with a hands-on “learning by operating” experience. The overall feedback was extremely positive with the participants clearly impressed with the course content and the realistic rendering and workings of an actual IGCC power plant.
Additional course offerings under development will include Introduction to IGCC Operations, IGCC Operations for Advanced Operators, IGCC Combined Cycle Operations, and IGCC Gasification Process Operations. The state-of-the-art simulation facilities are located at NETL in Morgantown, WV, and at West Virginia University's National Research Center for Coal and Energy, also in Morgantown.
While serving primarily as a training and education facility, the Center also offers unique opportunities for research collaborations in dynamic modeling and process control, interaction with internationally recognized energy experts, and software licensing.
What's in the Future for AVESTAR?
In the next phase of the training simulation, AVESTAR will incorporate Invensys Operations Management's EYESIM™ software to add 3-D immersive virtual reality to the training experience. The EYESIM solution extends training beyond the control room, allowing the field operator to perform manual maintenance and other day-to-day tasks and responsibilities from anywhere within the process plant.
Wearing a stereoscopic headset or eyewear, trainees will enter an interactive virtual environment that will allow them to move freely throughout the simulated 3-D facility to study and learn various aspects of IGCC plant operation, control, and safety. Such combined operator and immersive training systems go beyond traditional simulation and include more realistic scenarios, improved communication, and collaboration among coworkers.
NETL and its partners plan to continue building the AVESTAR portfolio of dynamic simulators, immersive training systems, and advanced research capabilities to satisfy industry's growing need for training and experience with the operation and control of high-efficiency, near-zero emission energy plants. To learn more about the center and training capabilities, visit the AVESTAR website at www.netl.doe.gov/avestar.