A $50 million expansion project will increase the efficiency and more than double the capacity of the Abbott Power Plant at the University of Illinois at Urbana-Champaign, which has been producing steam and electricity for more than 60 years.
The infrastructure enhancement is part of the university's long-term utility planning to support campus growth, said Keith Erickson, UIUC utilities director. Abbott, a cogeneration facility, was built in 1939 and upgraded in the late 1960s. Some of the equipment is original.

Abbott "seems to be on a 30-year cycle," he said. "This is our generation's chance to contribute."

Producing Energy

Cogeneration is the simultaneous production of two forms of energy in a single thermodynamic process. In this case, Abbott produces steam and electricity from natural gas, fuel oil and coal. That steam is distributed via 8.7 miles of steam tunnels and 9.2 miles of direct-buried steam pipes to warm 157 campus buildings, cook food and heat water. Abbott produces about one-third of the campus' electrical demand, and the rest is purchased from Illinois Power, a utility company.

The addition, designed and engineered by Muscatine, Iowa-based Stanley Consultants, includes two 12.5-MW gas-fired turbines, each with a supplementary natural gas-fired heat recovery steam generator (HRSG); two 12.5-MW extraction/condensing steam turbines; a 7-MW extraction/back pressure steam turbine; and the housing for it all. The footprint of the rectangular-shaped building is about 150 ft. by 120 ft., and its height is about 70 ft.

A Weighty Project

A critical component of the plan was a proper foundation, said UIUC engineer John Kaczmarek.

"This is not light construction," he added. "The equipment weights are fairly substantial."

The gas-fired turbines weigh 100,000 lbs. each, and the HRSGs weigh 182,000 lbs. In total the equipment weighs close to 1 million lbs.

Excavation for the lower levels, 14 ft. and 10 ft. deep, began last summer. Just as the cast piles were ready to be drilled, heavy rains set in and didn't let up.

"We had six water pumps running throughout August," recalled Colin Logue, project manager for Felmley-Dickerson Co. of Urbana.

Once the skies cleared, Felmley-Dickerson anchored the site with 300 auger cast piles, which are similar to a caisson but without the steel shaft.

"We've got 300 of those guys there in all different directions, and the footprint is not that big," Logue added.

Also supporting the massive equipment are thick concrete floors, pads and walls. On the lower levels are the condensers, electrical and pumping equipment. The turbines are at grade, and the HRSGs are elevated about 30 ft. above the gas turbines.
The gas turbines sit atop a 3.5-ft. foundation that is reinforced with an upper and lower mat of steel rebar running at 6-in. intervals. The steam turbines are anchored to a pier and pad structure to isolate their vibrations.

"There's an awful lot of metal," said Gary Phillips, Stanley's onsite project representative.

Logue said there are about 640 tons of structural steel. "There are a few beams that weigh 9 tons each, which support the HRSGs and the roof structure," he added.

Working in a Tight Site

Once construction was under way, the crews dealt with a constricted space.
"You're at an existing plant so you don't have the opportunity of a large laydown area for materials and storage," Logue said. "We've done a lot of scheduling so everyone can get work done and that we've got room when the turbines and boilers arrived."
Delivery of the massive equipment was a step that required particular care if not outright strategy. Some of it came by trucks but the 18-ft.-high, top-heavy HRSGs came by rail from Lincoln, Neb. A spur adjacent to the power plant would have facilitated the process except for the fact that it was going in the opposite direction. Special permitting, self-leveling trailers and a 5-mile detour were needed to transport the machines those last few feet.

The railroad gave the crews a window of six hours on a Sunday, from 6 a.m. til noon, to offload the HRSGs, which were welded to the railcars. To save time, the welding was sawn through prior to the move.

Barnhart Crane & Rigging Co. of Ottawa, Ill., finished the lifting, loading and moving job by 10:30 a.m.

"Illinois Power and the local cable television provider had to stand by and lift up their lines as we went along," Phillips said.

Meeting Schedule, Budget

The project is on schedule and within budget. The new equipment was tied in to the existing system and valved-off during spring break to cause minimal disruption to the university and students. Plans are to have one gas turbine and HRSG generating by July and substantial completion of the rest by late fall. Then comes the tweaking.
"There is always something you can do to a power plant, just like there is always something you can do to a house," Erickson said.

The construction team praised the coordination efforts of each discipline and the respect each had for the others.

"We've certainly tried to recognize a team approach to put together the project," Phillips added. "We've had extremely good cooperation with contractors."

Kaczmarek said all the contractors were motivated and worked hard.

One of the big advantages to the Abbott plant is its flexibility, he added. The university has a variety of energy options depending upon the availability of equipment and fuel.
"For example, if our coal boilers are down for maintenance or repairs, we can switch over to something else," Kaczmarek said. "And one of the nice things in being able to use multiple fuels is that we can choose whichever is most convenient and most economical."