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Vol. LVII, No. 17
August 26, 2005
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Jet Engine Yields Electricity, Heat
Cogeneration Power Plant Adds Steam, Watts to Campus

On the front page...

Operating nearly noiselessly and producing only the slightest whiff of exhaust, a state of the art "cogeneration" power plant recently came online at NIH. It provides 23 megawatts of electricity (about 40 percent of campus needs) and tons of steam (about 30 percent of what NIH requires) to both heat buildings in winter and sterilize scientific equipment (in autoclaves) year round.

Continued...

 
Cogen stalwarts (from l) Dr. Farhad Memarzadeh, John Fratangelo and Joseph Nieves at the Bldg. 11A plant  
The $38 million facility, built as a sidelong appendage to the Central Utility Plant at the heart of campus, is currently owned and operated by Pepco Energy Services, but will become government property in 10 years. Conceived of as a more efficient and environmentally friendly alternative to purchase of another traditional boiler to meet NIH's rising steam needs, the cogen plant is expected to save more than $15 million annually over the life of the system.

The plant is also expected to reduce pollutant emissions by 600 tons per year, compared with a traditional boiler, and to reduce future carbon dioxide (a greenhouse gas) emissions by some 100,000 tons per year, according to Dr. Farhad Memarzadeh, director of the Division of Policy and Program Assessment, Office of Research Facilities, who is also a leading researcher in bioenvironmental studies. The plant, which has already won a slew of honors for cleanly conserving energy and water, will save more than 640 million BTUs per year, equivalent to the energy use of about 5,000 homes.

Those are the plant's glittering SAT scores, but it took a lot of grit to get there, according to Memarzadeh. He first began pitching cogen as an alternative energy source in the early 1990s, shortly after arriving on campus as an engineer with the NIH Facilities Program. Cogen, he explains, is simply the simultaneous production of electricity and thermal energy from a common fuel, in this case natural gas. It's an ideal technology when there's a consistent need for steam and wattage.
The cogen plant occupies only the left portion of the Bldg. 11 complex shown here. The steel stanchions in front of the cogen facility are a framework under which portable oil-fired boilers can be rolled, for occasions when the gas turbine is shut down for maintenance or repair. The two giant header pipes would carry steam into the plant for dispersion across campus.Notice, too, the segmented chimney coming out of the roof at upper left, which helps disperse emissions.

The heart of the plant is an ABB GT10 jet engine built in Sweden and selected largely because it produces less than half the nitrogen oxides of other commercial turbines. "This is the cleanest cogen facility in the entire world," said Memarzadeh.

 
Combustion gas generator rotor ready for installation in the combustion turbine. Washington Gas delivers natural gas to NIH at a pressure of 15 pounds per square inch. A 1,200-horsepower Siemens gas compressor ups that pressure to 400 psi in order to feed the jet engine.  
Fed a diet of highly compressed natural gas, the combustor burns at around 3,000 degrees Fahrenheit and generates a turbine speed of about 7,700 revolutions per minute. About 30 percent of the energy generated is converted to electricity, and 55 percent is converted to steam, which is generated in a boiler at a temperature of around 300 degrees F.

Only about 15 percent of the heat is "wasted" as exhaust, which spirals up through a unique chimney with segments incorporating lands and grooves that act much like the rifling in a gun barrel, sending emissions winding upward to disperse in a more desirable pattern.

The 7,800-square-foot plant broke ground in 2000 on the site of NIH's former waste incinerators, which past NIH director Dr. Harold Varmus closed due to community concerns. "We wedged about 10 pounds of stuff into a 3-pound bag," quips Memarzadeh of the tightly packed building. According to John Fratangelo, a vice president at Pepco Energy Services, Bldg. 11A, the cogen plant, is only about half the size of operations with similar output. "There isn't an extra inch of space."

Highly automated, with more than 12,000 sensors and many miles of cables arrayed in trays emanating from the machinery, the plant requires a round-the-clock staff of only 2 or 3, who occupy a small office dominated by computer screens. The utility-grade computer monitors, duplicates of which Memarzadeh also has on his desk in Bldg. 13, graphically represent every aspect of the plant's operation, from input to output. Temperature, RPMs, pounds of steam pressure delivered, wattage being generated — it's all there on the screen.

Cogen plant supervisor Nieves, a veteran of the U.S. Navy’s nuclear-powered fleet and a Pepco employee, mans a graphic display of all plant operations. The same monitor sits atop Memarzadeh’s desktop in Bldg. 13. Power turbine ready for installation in the combustion turbine connects to generator to produce power.

Adjacent to Bldg. 11A is the Central Utility Plant, which houses five traditional gas and oil-fired boilers that produce steam. Interestingly, the condensate (water left over at the end of the steam tunnel's 2-3 mile circuit around campus) from Bldg. 11 is reused, after some mild chemical tweaking, in the cogen boilers. NIH could simply have added another boiler to meet steam demand — it would have been cheaper to build, easier to get permits, and the hardware would already be familiar to power plant staff. But NIH is already at the limit of allowable air emissions, explained Memarzadeh. "The cogen enabled us to meet National Ambient Air Quality Standards more effectively and economically than traditional boilers," he
NIH cogen plant facing east, looking down on combustion turbine package from heat recovery steam generator (boiler)
said. "The reason behind this is the stringent requirements that NIH imposed on the contractor. If the contractor didn't meet the emissions requirements as stipulated, Pepco would have been penalized at the rate of $500,000 per one part per million (ppm) deviation from the contract limits." Observed Leonard Taylor, who recently left NIH to lead the facilities operation at the University of Maryland at Baltimore, "Cogen allowed us to grow the campus and stay within the emission standards."

In many ways, the cogen plant represents a series of triumphs over seemingly show-stopping limitations — the site was small, in a busy part of campus; 9/11 happened and made construction far more difficult; many argued NIH had no business generating electric power, and were wary of a jet engine on campus — would it be loud, would the compressed gas pose the danger of explosion?

Memarzadeh, with the support of senior leadership in the Office of Research Services, fought for more than a dozen years to see the project past each obstacle, creating highly technical scientific and economic models proving that cogen would eventually be win-win for NIH. When he began preliminary reports on the subject in the early nineties, he didn't have the family obligations that he has now with two young children, the oldest of whom is 12. "I would probably not be able to devote the time required to complete this project, if I had to start it now. It was an enormous effort," he said.

Control room operator Henry Valle of Pepco, who like Nieves is a Navy vet, checks boiler water quality.
Interestingly, the cogen was just one of many projects Memarzadeh was responsible for in the past decade. As a research scientist, he has published many articles, monographs and books on air quality requirements in health care and biomedical research settings, and has been invited as guest and keynote speaker at more than 50 national and international engineering and scientific seminars, conferences and symposia. The Department of Energy also named him an "Energy Champion" for proposing an innovative use of turbine generators for steam-pressure reduction at the Clinical Research Center. The system helped HHS save $1.5 million in new construction costs and $170,000 in future annual energy costs.

"Without Farhad, the technology for [the cogen project] wouldn't exist," said Taylor. "This is really cutting-edge technology, especially how clean it burns. We initiated a concept and proved it could work. We turned a hypothesis into reality — and titanium [the turbine rotors are made of this very strong metal].A combination of mechanics and thermodynamics gave us this result."

Combustion turbine installed and in operation, sheathed in insulation

Memarzadeh concluded, "The cogen project was an extremely complex one that presented numerous unforeseen conditions, but the project was completed within budget. The success of cogen was a result of others' efforts besides my own. If it weren't for the help of construction project managers Reza Jafari of NIH and John Fratangelo of Pepco and the NIH contract officer, Ken Roman, the cogen could not have been built."

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