Location: Long Island, New York, USA
Application: A grass root facility. Noise control of (2) 5.7 MW gas reciprocating engine-generators, hybrid, high efficiency, cogeneration (CHP) units in which waste exhaust gas is cooled and used in a proprietary process.
The Issues:
Sound Level Criteria: The facility consists of a power house building, process building and storage building, and is located within approx. 65ft (20 m) of residences where a sound level < 50 dBA is required by local codes.
Scope of work: NVC Olsonfab was to determine the powerhouse building ventilation air movement / flow requirements and to design and supply noise control treatments for the multiple, noise sources of the power house building.
The Sources:
- Power house building walls and doors
- Ventilation- fan forced inlets and natural draft discharges
- Engine combustion air inlets
- Engine combustion exhaust gas outlets
Engineered Solutions:
- Power house building walls and doors were assembled from NVC Olsonfab Quietwall, noise reducing panel system with STC 52 rating. The system consists of structural components, sound reducing panels and seals which combine to provide a structural, noise reducing, thermally insulated assembly, which is speedy to install without special tools or personnel.
- Ventilation System. Maximum capacity 180,000 CFM.
- Air inlet. located in wall. Fan forced. (2) two systems combined in one unit.
- System 1 – providing air cooled by integral cooling coils reusing water from the process side.
- System 2 – providing ambient air
- VDFs and dampers are used to adjust air flow rates for year round operation.
- Air Discharges. Quantity (5) five. Located on roof. Natural draft.
NVC Olsonfab’s high performance rectangular duct silencers with high transmission loss (HTL) shells were incorporated to provide noise control for the power house source noise as well as the ventilation fan noise. Overall noise reduction > 55dBA.
- Engine Combustion Air Inlets. Quantity (2) two. Located on roof.
NVC Olsonfab’s high performance, rectangular, industrial, reactive/absorptive elbow silencers with high transmission loss (HTL) shells were incorporated to provide reduction of the combustion air intake noise. Overall noise reduction of > 65 dBA. Also, supplied were NVC-Olsonfab in-line air filter modules to provide filtration of the combustion intake air.
- Engine Exhaust Gas Outlets .Exhaust piping and exhaust stacks/silencers. Quantity (1) one for each of (2) two engines. Located on roof. Each engine has dual turbochargers.
NVC Olsonfab supplied high transmission loss, thermally insulated exhaust piping from turbochargers to 70 ft. (21.3m) high, self-supporting exhaust stacks. A reactive/absorptive silencer was incorporated into the bottom section of the stack with high transmission loss (HTL) shell. Overall noise reduction (insertion loss and transmission loss) of the complete exhaust system was > 55 dBA.
