Issuu on Google+

ENERGY CONTROL CENTER: The University of Iowa’s biomass cofired power plant has 24/7 coverage from four shifts of four operators. The plant also has an operations day staff and engineering staff, who help review big picture data to determine trends. PHOTO: UNIVERSITY OF IOWA

nance is done consistently between assets and in compliance with all required regulatory requirements.” Another biomass power producer with years of operational experience is Minnesotabased Great River Energy’s Elk River Energy Recovery Station. This retrofitted waste-to-energy plant converts up to 1,050 tons of refusederived fuel per day into as much as 30 MW of energy. The plant deploys Emerson’s 1500DST DeltaV system to monitor and control the plant, consisting of three boilers, three turbines, fuel handling and baghouse. Mark Holt, senior engineer, says a bulk of the monitoring they do is tied into that system. As an engineering and technology company, Emerson offers a number of equipment condition monitoring including online vibration monitoring, motor diagnostics, infrared thermography, laser alignment and balancing and oil analysis. Eagle Valley’s biomass plant in Colorado is fairly new, commissioned in 2012, and just recently restarted operations in February, due to a fire that put the plant out of commission in

late 2014. In this day and age, Wait says, when smaller plants are built under full EPC contracts, it makes sense to rely upon the engineering staff ’s monitoring recommendations. The primary system deployed at Wait’s plant was developed by Wellons. “Equipment might be slightly newer, different than your operational staff ’s experience,” Wait adds. “I think in a new plant today, the monitoring systems typically outpace the experience of the operating personnel.”

Track and Trend

Since CM is based on trending, it requires that baseline conditions be defined so there is a reference point for comparing and interpreting the obtained data. Overall, plant processes should stay within a standard deviation, and if a change occurs in the trend, it should be linked to some process or mechanical variable. “Almost all of the parameters that are monitored electronically have some sort of expected range of operation, and if the parameter goes outside

of that range, the computer system will signal an alarm,” Wait says. He shares that his staff takes the time to understand why there was an alarm, what the parameter values are, and then troubleshoots the issue. Holt adds that, in addition to alarms, certain components are designed to shut down or trip to prevent further damage to the equipment if something goes awry. According to Holt, plant monitoring is all about creating a better user interface to understand what the alarms and numbers mean, so it can be easily interpreted and used to make improvements. According to Justin Price, principal with Evergreen Engineering, the real trick is knowing what to measure, how it’s trended and how you’re going to use that data. “If you’re measuring the wrong thing, then you might be going after the wrong key performance indicators (KPIs),” he says. The staff running UI’s power plant measure several KPIs associated with safety, maintenance costs, operational efficiencies, the percentage of renewable energy and more. One


2017 January Biomass Magazine