Waste Management Energy Solutions Inc.
A waste-to-energy generating facility, Bradley’s Sun Valley plant produces power for its own use, and the local public power grid. The facility is comprised of five gas conditioning skids. The facility utilizes five electric generator sets powered by Deutz TBG 620 V16K engines, fueled by methane gas produced by the landfill’s contents. Generator sets drive a series of 4160 a.c. 3-phase 60 Hz generators, with an output of 1358 kWe at ISO 3046/1. The facility is capable of producing 6.5 MW of electricity, enough to supply between 6,000 and 7,000 homes.
SCOPE OF WORK
A noise measurement and control study was completed at the site to determine noise sources.
INNOVA designed, supplied and installed acoustic equipment enclosures and acoustically treated engine exhaust outlet with horizontal and vertical silencers. Genset enclosure ventilation fans were treated with lined weather hoods.
Radiator hoods, gas conditioning skid blower, motor and piping were treated with shrouds.
Design work was based on the results of acoustical surveys and their analysis, both of which were undertaken by INNOVA.
The retrofit utilized proprietary lightweight roof and wall assemblies designed specifically to mitigate low-frequency noise.
INNOVA’s acoustic design goal for the facility was to limit noise level to one dB above existing ambient levels and to meet a level of 30 dB(A), within the immediate neighborhood. The cumulative sound level was not to exceed 36.7 dB(A). At this level, noise from the facility would no longer be perceptible.
Five gas engines and generators, exhaust muffler, radiator coolers for the engines and ventilation fan components. The center’s gas conditioning skids motors and blowers were also major noise contributors.
UNIQUE PROJECT HURDLES
The facility is located adjacent to a residential neighborhood. While the plant was operating within regulatory requirements, complaints and comments had been received by nearby residents with respect to low frequency noise. As each of the five engines was packaged separately, the project called for separate application measure for each generator set enclosure, rather than a single acoustic building or barrier. The radiator coolers located on top of the gen-set enclosures was particularly challenging. The shroud systems were installed to allow inlet air to enter at the bottom, while an exhaust silencer was installed on top to mitigate the flow through from fans. The facility had been constructed on a portion of the landfill. Considerable analysis and investigation was required to address potential land settlement issues.
The project was successfully completed within a three-month period, on September 10th, 2004.