1-6 Noise

Please explain in detail all noise suppression/mitigation efforts that are being proposed by the facility.

RESPONSE:

 

As indicated in Section 6.9 of Invenergy’s EFSB application and on page 34 of Appendix E, the proposed extensive acoustical design of the CREC includes;

  • installation of the combustion turbines and steam turbines within buildings;
  • high-performance silencers installed within the air intake ductwork of the combustion turbines to reduce high-frequency (spectral) compressor and turbine blade aerodynamic noise;
  • silencers installed on fans providing ventilation air for the combustion turbine enclosure compartments;
  • low-noise air cooled condensers and closed cooling water heat exchangers;
  • combustion turbine exhaust diffuser is located within the building;
  • combustion turbine exhaust noise attenuated via the SCR/HRSG units and high-performance exhaust stack silencers;
  • auxiliary boiler FD fan intake silencer banks;
  • low-noise GSU transformers; thicker casings for the HRSG boilers and transition ducts;
  • buildings enclosing the auxiliary boiler, gas compressors, boiler feed water pumps and water treatment equipment;
  • acoustical enclosures over the duct burner skids; acoustically louvered ventilation openings for the auxiliary boiler and generation buildings;
  • the installation of a low-noise steam bypass system including low-noise valves and steam discharge stack resisters (disk stack);
  • silencers on startup vents, blowdown and drains tank vents; and silencers on safety release vents.

The specific noise attenuation features included in the CREC design were shown on Table 9 of Appendix E, shown below:

 

Table 9: Proposed Acoustical Design

Equipment Item

Control

Air Cooled Condenser

Low-Noise Design

Auxiliary Boiler

Enclosed within a Building

Auxiliary Boiler FD Fan Intake

High-Performance Duct Silencer Banks

Auxiliary Boiler Louvered Ventilation Openings

Acoustical Louvers

Auxiliary Boiler Startup Vent and Blowdown Tank

Vent Silencers

CCW Heat Exchanger

Low-Noise Design

Combustion Turbine Air Intakes

High-Performance Air Intake Silencers

Combustion Turbine

Enclosed within a Building

Combustion Turbine Ventilation

Ventilation System Silencers

Combustion Turbine Exhaust Diffusers

Enclosed within a Building

Combustion Turbine Exhausts

Exhaust Mitigated via SCR/HRSGs and High-Performance Exhaust Stack Silencers

Duct Burner Skids

Acoustical Enclosures

Fuel Gas Compressors

Enclosed within a Building

Generation Building Louvered Ventilation Openings

Acoustical Louvers

GSU Transformers

Low-Noise Design

HRSG Blowdown Tanks

Vent Silencers

HRSG Boiler Feedwater Pumps

Enclosed within a Building

HRSG Boilers and Transition Ducts

Thicker Casing

Steam Safety Release Vents

Vent Silencers

Steam-Turbine

Enclosed within a Building

Steam turbine bypass system

Low Noise valves and steam discharge stack resisters

Steam Turbine Drains Tank

Vent Silencers

Water Treatment Equipment

Enclosed within a Building

 

RESPONDENT:

 

Mike Hankard, Senior Acoustical Consultant, Michael Theriault Acoustics, Inc. and John Niland, Director, Business Development, Invenergy

 

 

DATE:

March 31, 2016