IGCC 3D Virtual Immersive Training System (ITS)

The AVESTAR™ Center features an immersive training system (ITS) for an IGCC plant with carbon capture. In the fossil energy industry, electric power utilities are continually striving to better train their workforces to operate power generation plants in a safe, reliable, environmentally friendly, and profitable manner.  Real-time dynamic simulators with ITS capabilities are one of the best ways to prepare engineers for the operation and control of advanced next-generation power plants with carbon capture. 
   
Using innovative 3D virtual reality technology, the ITS adds another dimension of realism to the real-time IGCC operator training system (OTS) deployed at the AVESTAR™ Center.  Using gamepads for navigation and 3D visors with head tracking, ITS users can interact with plant equipment items (e.g., gasifier), activate transparent views (e.g., liquid level in a tank), display pop-up trends (e.g., gas turbine combustor temperature over time), and experience equipment sound effects (e.g., pump engines), malfunctions (e.g., leaks, fires), and visual training scenarios (e.g., CO₂ absorber column operation).

The ITS extends the training scope to both control room and field operators, allowing them to work as a team.  The training covers base load operation, normal shutdown, load shedding and following, fuel switching, and complete cold, warm, and hot startups.  The combined OTS and ITS solution handles emergency shutdowns and rare abnormal situations in real-time (including equipment malfunctions and failures), together with changes initiated through actions from the instructor station or from field operators.  Such comprehensive simulator-based instruction allows for realistic training without compromising worker, equipment, and environmental safety.  It also better prepares operators and engineers to manage the plant closer to economic constraints while minimizing or avoiding the impact of any potentially harmful, wasteful, or inefficient events.  Additional benefits include improved communication and collaboration among work crews, off-line evaluations of procedures, and training for safety-critical tasks. 

ITS Software and 3D Immersive Virtual Reality Model

The IGCC immersive training system is implemented as a virtual reality (VR) software application that provides a real-time, 3D immersive, plant walk-through environment for training field operators and engineers.  The VR environment lets the user move and interact freely within the plant, without being bound to prefixed paths or animations.  Any action that the field operator carries out in the 3D environment is immediately reflected in the IGCC dynamic simulator and, conversely, any value that is updated by the simulation interface is also updated in the VR platform.  A 3D visor with head tracking is provided for training a single field operator.  Stereoscopic projectors are provided for training multiple operators using shutter glasses.  Other peripherals include gamepads for navigation and a backup and storage system.

A photorealistic 3D VR model has been generated to provide the context in which the ITS user feels immersed in an actual IGCC power plant.  First, a 3D computer-aided design (CAD) model was built on a real-world scale (1:1) from the process and instrumentation diagrams (P&IDs) for all major IGCC plant sections, including air separation, entrained-flow gasification, synthesis gas cleanup, water gas shift, dual-stage acid gas removal process for hydrogen sulfide and CO₂ capture, Claus plant for sulfur capture, CO₂ compression process, and combined cycle for power generation.  Next, the 3D CAD model was used to create an interactive and immersive VR plant environment composed of geometric component models with appropriate material and lighting information.  The four main categories of component models include the active equipment items (e.g., pumps, heat exchangers), active instrumentation (e.g., valves, control panels), non-interactive structures (e.g., piping, stairs, floors), and the background scenery (roads, distant plant sections, sky, landscape). 

To increase the visual realism, all 3D component models make use of textures and shading, derived mainly from pictures taken of real plants.  In this project, the 3D VR model has been enhanced using high-resolution photographs from commercial-scale plants, including IGCC systems.  Stereoscopic 3D pictures were taken during the photography sessions at the visited plants.  In addition, videos recorded in high definition were used to create a 3D spatial point grid for correct positioning of all plant components.   The final photorealistic 3D VR model of the entire IGCC plant has been implemented as an immersive and interactive training application.

Virtual Interaction

For all processes in the IGCC system, the ITS is capable of providing virtual plant interactions for those equipment items that are operated from the control room and/or from the field and necessary to support all training objectives.  The user can navigate an avatar (field operator) through the 3D virtual plant using a gamepad, a gesture-sensitive handheld device used as the primary means of input for most modern video games.  During plant navigation, the user can select and interact with active instrumentation and equipment components that are linked to the operator training system.  The IGCC dynamic simulator realistically responds in real-time to the field operator action where actions such as opening or closing a manual valve are required within the scope of the simulation.

Figure 1 shows a transparent view for a distillation column in which the animation of the flow rates of the vapor and liquid up and down the column, respectively, are tied to real-time process variables in the dynamic simulator.  For all transparent equipment items, the visual representations will be interactive and depend on the process conditions as generated by the dynamic simulator linked in real time.

In Figure 2, the shell of a reboiler is transparent, visualizing the tube sheet with corresponding boiling liquid and generated vapor flow.

The ITS user can select equipment components and activate a transparent view as shown in Figures 1 and 2. 

    

In addition to interactive actions and reactions with transparent equipment objects, collision geometry and pop-up variable trends over time are some of the additional functionalities that are provided.  The ITS also offers several weather and lighting combinations, including a clear sunny day, a cloudy day, and a cloudy day with rain or snow.  The VR environment will also provide sound rendering effects that increase the sense of immersion for the user. These will include constant low-intensity background sounds (e.g., distant equipment), random environment sounds (e.g., flock of seagulls), and equipment-specific sounds (e.g., pump engines, sirens).

As shown in Figure 3, the virtual plant can be used to practice training routines for malfunctions and emergencies that could not be attempted in the real plant (e.g., leaks, fires).  In another malfunction example, rupture of the pure oxygen piping at the outlet of the oxygen compressor in the air separation unit progresses to light smoke and then heavy smoke followed by a large fire that requires isolating the oxygen compressor by closing the appropriate valve, shutting down the compressor, and switching over to the oxygen supply from the oxygen storage tank.  Gasifier operation will be affected as appropriate, based upon the severity of the rupture and reduction in oxygen supply to the gasifier.  

Figure 3 shows gas leaking from a pipe in the Claus plant area.

A number of visual training scenarios are also designed to promote a better understanding of gasification and CO₂ capture technologies.  For the gasifier, a visual representation is displayed as a semi-transparent view showing operational changes from initial ignition to full combustion and subsequent gasification at normal operation.  For the CO₂ capture process, a detailed transparent view of the liquid and vapor flow rates in the CO₂ absorber column displays a noticeable change as the absorber responds to load shifts and switching from one acid gas removal train to a two-train operation and back.  This will promote better understanding of absorber column operation as well as enhance the simulator as a showpiece for carbon capture.

Last Word

Looking to the control room of the future, AVESTAR™ researchers have the vision that immersive 3D virtual reality technology can become the new operator interface for next-generation energy plants.

*NETL's AVESTAR™ Center will offer hands-on, scenario-based training on the IGCC immersive training system in mid-2012.