By Jim Montague, Executive Editor
Time speeds up as we get older, but 10 years is still a big chunk of chronology. And in this stressed-out era of 24/7 news, showbiz fads, financial scandals and other distractions, it can be difficult to focus on unglamorous commitments—good marriages, raising families, consistent professionalism— or staying warm next to Lake Michigan.
Sure, global warming may one day turn Milwaukee into a tropical hotspot, but, for now, most of its downtown area by the lake needs the steam heat it gets from We Energies' Valley Power Plant. This venerable plant is the largest utility-owned, co-generation facility in the United States. It haa two 280-megawatt units, and its four coal-fired boilers produce 1.25 million pounds per hour (MLb/hr) of steam.
In the most recent decade of its continuing mission to provide and improve its service, Valley Power has steadily transitioned from using stand-alone laptop PCs and multiplexers and moved to using Emerson Process Management's online AMS Device Manager and its Ovation interface. This journey was described by Todd Gordon, We's instrument technician leader at Valley Power, at the recent Emerson Global Users Exchange in San Antonio, Texas.
"Now, we all have to love technology, but we know it can create an overload unless training and implementation are coordinated," says Gordon. "We've also learned that technology such as AMS can't solve every problem. If your hardware and mechanics aren't set up properly, then your overall system isn't going to work. Technology is only as good as the people that maintain, use it and interpret the data, so it also takes a time commitment for training, proper setup and implementation."
Built in the 1960s, Valley Power initially used local, pneumatic controllers for pressure, temperature and level and an I/P converter, which was upgraded from E/P in 1993. Gordon reports the plant's journey to AMS really began when it installed its first "smart," non-HART transmitter in 1988. Then, in 1993-94, DCS controls were installed at Valley Power. Likewise, in 1993, the plant gained its first "smart," non-HART positioner, which used DOS-based software that required a Windows 98 laptop.
"The main question is can the newer, smart instrument do its job better than the older technology? We've usually found that the answer is yes," says Gordon. "Fisher DVC positioners also provided an input to DCS for valve position from the HART signal. These were on our two most critical valves. So when the positioners told us the valves were getting sticky, we decided to replace them, and this saved us from tripping out units three times."
Later, Valley Power added Base Station with Multiplexers in 2004. These enabled online, continuous monitoring when hardwired to HART devices. "The base station communication from the handhelds and laptops are very useful, but we still like to go and see the valves move," added Gordon. "There are still some things you can only see when you're there."
Even newer devices at Valley Power include its HART diagnostic transmitters, and it plans to add wireless devices soon. Most recently, the plant replaced its multiplexers with Emerson's Ovation interface and spent part of this year working on a new DCS controls upgrade, in which the base station will be integrated into the DCS controls.
"In general, our performance monitoring has given us better tuning of controls, improved heat rates for reduced fuel consumption, faster ramp rates for changing load demands, centralized performance monitoring and predictive maintenance," added Gordon. "All of this has been a journey, not a destination. We found that online capabilities increase effectiveness of smart instrumentation and supporting software. However, you can't maximize a plant's efficiency if you can't accurately control and effectively manage the final drive elements."
Pretty cool, that is, if you can wake up from present-day distractions, become aware of some important history and take that longer view.