U.S. Veterans Affairs, Dallas Medical Center, CHP Plant
Stanley Consultants served as the design engineer of record for this design-build project in partnership with contractor McCarthy Building Companies. The VA is expanding the central energy facility to include cogeneration. The existing facility produced steam and chilled water for heating and cooling with all normal electricity provided by the local utility. The new installation added a nominal 4.5 MW recuperated gas turbine with a heat recovery steam generator. The gas turbine is sized to supply approximately half of the hospital complex normal electrical requirements.
The gas turbine generator is located outside and immediately adjacent to the existing steam generating portion of the facility. A screen wall, around the gas turbine, acts as a visual barrier and maintains the campus architectural appearance. The heat recovery steam generator is located inside the current boilerhouse in space created by removing one of the existing four boilers.
The gas turbine has inlet air cooling to allow the gas turbine to operate at near rated capacity during hot summer months. The heat recovery steam generator (HRSG) will be auxiliary fired with natural gas, No. 2 fuel oil or Bio-diesel fuel. The HRSG will produce approximately 14,000 pounds per hour of 100 psig saturated steam unfired and 45,000 pounds per hour fully fired.
In addition, the electrical utility supply to the entire campus was revised. The new design will include two, 100% redundant utility feeds. Normal operation is with one feed supplying the excess power required by the hospital complex above that produced by the gas turbine generator. The second utility feed will act as a back-up supply. The gas turbine is able to provide power to any of the buildings at the facility. In the unlikely event of a total power failure, the gas turbine generator can operate in an island mode and provide power to the facility up to its rated capacity.