By Jim Montague, Executive Editor
How can you play power chords on a Stratocaster if the strings aren’t there? Most youngsters would likely say all you need is a guitar-like interface with lots of colorful buttons. So, if you need training on a process control system that hasn’t been built yet, what you need is a good simulator.
Figure 1. Staffers at Con Ed’s East River Repowering Project in New York City learn to run their new truncated, combined-cycle, 320-megawatt power plant with help from Emerson Process Management’s Scenario simulation software.
This latest, multi-million-dollar, East River Repowering Project (ERRP) migrated the plant from boiler/steam turbines to new truncated, combined-cycle equipment, including two new GE gas turbines, two heat-recovery steam generators (HRSGs) and one steam ring header. Basically, the gas turbines generate electricity, and the HRSGs recover waste heat to make 1.2-1.5 million pounds/hour of steam more efficiently for heating and cooling Manhattan’s numerous skyscrapers. However, these new technologies meant there was no way for Con Ed’s operators to get the training they needed ahead of time.
“We starting adding design data into our simulator, so the Dell PCs running the simulated plant model ensure the simulator’s Sun Microsystems’ Solaris operator workstations provide power plant control data consistent with the workstations on the actual plant control system. These workstations allow plant operators to monitor pressure, temperature, flow elements, valves, current and voltages,” says John Mansell, shift supervisor at Con Ed’s East River facility. ERRP uses Emerson Process Management’s Scenario simulation technology and its Ovation control system. “We used to train in classrooms and do on-the-job training (OJT), but this retrofit’s new technology meant that OJT wasn’t available, and so it was even more important to simulate start-ups, shutdowns and other scenarios.”
To Training and Beyond
While seeking the best ways to educate their operators, Con Ed’s engineers also evaluated how ERRP’s simulation logic was going to work at East River and found they could pretest the system before commissioning. Doing this uncovered items that might otherwise not have been found, such as control of raw water to the plant, a lack of recirculation capability, and pump and valve cycles that weren’t the same type.
“The new gas-turbine and HRSG technologies extended through our plant’s distributed control system (DCS), but we didn’t know how they were going to work together before commissioning because we’d never integrated them in our DCS before,” says Hsiu-Chen Wang, senior engineer in Con Ed’s Central Engineering and Mechanical Controls group. “By putting all these elements together in a simulator before commissioning, we were able to check, verify and validate all these parts before start-up, and that was a tremendous help. In fact, we cut our start-up time from three or four months to just one month.”
Mansell adds that its $1.3-million simulation allowed ERRP to begin using an iterative process. For example, simulating designs before implementation turned up issues that could help revise those designs before startup. “So, when the plant went into full service, all the data from commissioning was loaded back into the simulator, which made it even better,” he explains. “The plant’s reliability is now better than 90%, and our operators can learn on a seamless simulation tool that’s the same as what they’ll use in the plant.”
Similarly, if Con Ed’s operators and engineers later find process improvements they want to do, these ideas can be tested on the simulator first and then taken to the DCS if they’re approved. “Simulation is much more than a teaching tool,” adds Wang. “It’s a multi-purpose device that can help every aspect of engineering and operations.” In fact, Mansell adds that Con Ed’s Scenario simulator even allows it to take some I/O points off scan and see how its real plant system would be affected. “This means we can go into the plant with a lot more confidence in the adjustments or repairs we have to make because we know more about the possible risks involved,” says Mansell.
Show, Don’t Tell
In short, Con Ed’s experience demonstrates why this motto is so useful to teachers and trainers. It’s because specific demonstrations are far more effective at conveying and instilling useful information than vague descriptions. Hands-on, on-the-job (OJT) training in any activity engages more of the body’s senses and neurons and so builds stronger pathways in the brain for deeper, longer-lasting learning.