Fired up at power plant
Under the watchful eye of engineers and school leaders, the new jet turbine roared to life, accelerated to synchronizing speed and ran for a total of 10 minutes, marking the successful “first fire” test at UMass Medical School’s power plant.
The new jet turbine and associated systems are at the heart of a 14,000-square-foot addition now under construction to boost the plant’s capacity to generate steam, electricity and chilled water while at the same time reducing its green-house gas emissions.
“This was a very big milestone,” said Joseph Collins, director of energy resources. “We still have quite a bit of work to do before we’re fully operational, but to have this first-fire test work well was a major accomplishment, and a strong team effort made it happen.”
The new turbine is a Taurus 70, made by Solar Turbines of San Diego. Fueled primarily by natural gas, but able to run on oil for backup, the jet turbine spins a shaft attached to a generator to produce electricity, while 910 degree exhaust gas from the engine flows into a heat recovery steam generator (HRSG) to produce some 60,000 pounds of high-pressure steam per hour. That steam will do triple duty: it will drive two of the plant’s existing electric generators, then move through the campus’ steam-line network to heat buildings and drive compressors that make chilled water for the campus’s cooling systems.
The turbine and HRSG arrived on campus last spring. After several months of work to build out the complex network of electrical, plumbing and mechanical systems that are required to control and support the new turbine, including installing a new flue in the power plant’s exhaust stack, the team planned a first-fire test for mid-December.
With personnel from the turbine’s manufacturer, the plant construction team, Skanska USA and observers from National Grid on hand, Stephan Chait, director of capital projects for the UMass Building Authority, pushed the button and fired up the turbine.
“These are complex installations, so to have it fire up the first time was impressive,” Collins said.
The test was a “no-load” run, meaning the generator section of the system was not engaged to create electricity. Several months worth of additional testing, calibration and integration work must be completed before the new turbine will generate electricity for the school’s gird. The first-fire test did, however, produce steam in the HRSG, although the unit will not be connected to the plant’s steam output system until additional testing and cleaning of the new steam lines is done.
The gas turbine will be fully on-line later this year, and one of the plant’s original gas and oil-fired steam boilers will be taken off-line and kept in reserve as an emergency backup. Since natural gas burns cleaner than oil, and the new jet turbine is highly efficient, the expanded power plant will actually have lower green-house gas emissions, despite its added energy capacity. Furthermore, the new turbine will incorporate a catalytic reduction system to remove pollutants before the exhaust gasses are discharged through the existing stack.
When the expansion is completed, the plant’s maximum electrical output will increase from 10 to 17.5 megawatts. The existing plant produces all the steam and chilled water currently needed on campus, and about half of the electricity used. The expanded plant will be able to meet nearly all of the campus’s electrical demand, even after the opening of the Albert Sherman Center, but the school will maintain a connection to the external utility grid to handle peak demand and for a backup resource.