Reducing costs by designing power plants to permit retrofit of selected noise controls

摘要

Designing power, petrochemical, or industrial plants to meet community-noise limits isusually expensive. Many uncertainties affect designing to meet a limit, including: overlyconservative or unrepresentative vendor noise data, limitations of ray-tracing software,questionable modeling accuracy beyond 1000 m, lack of TL and absorption data below 125Hz, unreliable IL data for pipe lagging at all frequencies, unexpected operating conditions,vendors not meeting their equipment noise limits, and atmospheric effects. Further, a lackof experience of any participant in the design process increases uncertainty. Includingsufficient noise controls to cover every possible uncertainty would be outrageouslyexpensive, and is likely to affect project viability. To meet moderate limits, incrementalcosts typically exceed one million dollars per dB reduction of predicted community-noiselevels, and more for stringent limits. Thus, a typical design margin of 3 dB may costmillions more than needed. A fundamental and widely accepted premise of noise controlengineering that controls must be included in the design and construction is not alwaystrue. Designing a plant relying on retrofit installation of selected, but not all controls, islikely to substantially reduce costs for noise control. This paper describes a successfulapplication of this approach.