Cooling, Heating, and Power Revolution at UIC

Engineered Systems, Dec, 2001 by John Cuttica, Ron Fiskum, Richard Sweetser

In the '90s, the University of Illinois-Chicago (UIC) began a plan to generate some of its own electricity. Now, the school is pairing that goal with energy recovery and subsequent distribution to build a long-term strategy for its two plants and 25,000 students. See how this type of design may be coming into its own in the era of deregulation.

The University of Illinois Chicago (UIC) was formed in 1982 by the consolidation of two campuses: the Medical Center campus, dating back to the 19th century, and the two-year undergraduate Navy Pier campus that had opened in 1946 to educate returning veterans. With 25,000 students, the UIC is the largest university in the Chicago area. Located just west of Chicago's Loop, UIC is a vital part of the educational, technological, and cultural fabric of the region.

UIC is growing rapidly and already has underway a 10-year south campus project including housing for more than 750 students, three major academic buildings, more than 850 units of market-rate residential housing, new retail establishments, and parking facilities. On the west side of campus, a $100-million College of Medicine research building and other new high-tech research facilities will be constructed by 2003.

To manage the energy needs of this thriving institution, the UIC fiscal plant team is continuing on a course originally begun in the early 1990s, when the university first started to generate some electricity for the east campus.

When complete and linked together, the east and west campus CHP plants will generate enough power to supply electricity to its entire 8-million-sq-ft (2.4-million-[m.sup.2]) campus, as well as provide steam for two neighboring hospitals, various state of Illinois buildings, and a few private entities.

"The east and west campus CHP plants are about one mile (1.6 kin) apart and are designed to operate as if they are a single plant," said Ken Buric, director of utility operations for the university. "We've installed a 69,000-V electrical line between the two campuses that will link the two CHP plants. A control system will determine which prime mover, or combination thereof, will operate based on the electrical and heating load."

EAST CAMPUS CHP PLANT

UIC began generating power at its east campus CHP plant in 1993. Two Cooper-Bessemer 20-cylinder LSVB engines drive Ideal Electric generators, each rated at 6.3 MW. The initial 12.6 megawatts elecrical (MWe) capacity of the plant served the base electrical load of the east campus.

Seven years later, two Wartsila 18V28SG engines driving ABB generators rated 3.8 MWe each were added to pick up the east campus' seasonal load, which is primarily the electrically driven centrifugal chillers in the university's central chilled water plant. This addition brought the east campus CHP plant's total capacity to about 20 MWe.

The Wartsila 28SG lean-burn engine is characterized by its high electrical efficiency, dependable operation, and low maintenance cost. The engines will be managed and monitored with a state-of-the-art control and supervision system, that will enable a reliable and flexible operation with a minimum number of personnel.

The east campus plant operates with the existing engines supplying the campus with electricity and thermal energy for heating and cooling. The plant is equipped with supplementary-fired hot water generators to efficiently meet the energy needs of the university.

Power at the east campus is generated at 12 kV and distributed to the buildings as 12 kV via a university-owned distribution system. Each building has switchgear, transforming 12 kV down to 480 V for building use.

"All engines at the east campus facility are equipped with high-temperature hot water heat recovery systems," said Buric. "The east campus uses 400[degrees]F (205[degrees]C) water and distributes it throughout the campus for heating and absorption air conditioning.

"The two Wartsila engines at the east campus have gas-fired afterburners for emissions control, and supplemental firing of the heat recovery boilers. This was necessary because the EPA considered the east and west CHP plants as a single source of emissions." On the Wartsila engines, heat is first routed through a gas-fired afterburner and then through heat recovery boilers. Engine exhaust from the Cooper-Bessemer engines is routed through heat recovery boilers with recovered heat tied into the campus' central high-temperature hot water heating distribution system.

The UIC east campus has two electrical loads. "Our nighttime load gets down to about 10 or 11 MWe. At 8 a.m., students wake up, coffee pots get turned on, people start using power, and the load goes up to about 12 or 13 MWe. It will hold there until around 4:30 or 5 p.m. when people go home. Our typical baseload, which is our wintertime load, is 12 or 13 MWe."

"In the summertime, it's a little different because the campus has a central chilled water plant. We've got 6,000 tons (21.0 megawatts thermal (MWth)) of electrically driven centrifugal chillers in our central plant, and it's supplemented by 1,350 tons (4.83 MWth) of absorption air conditioning out in the buildings. We distributed absorption chillers out in the buildings as a heat load specifically for the CHP plant and added a Trane 1,000-ton (3.5 MWth) absorber to our existing chilled water plant."