Feasibility of meeting a limit of 85 dB everywhere inside a power plant

In recent years the importance of acoustics in the construction of industrial plants has greatly increased. According to many regulations an employee may not be exposed to an 8-h time-weighted average A-weighted sound level of more than 85 dB. The requirement 85 dB at any point is easy to check, even for a nonacoustician. Therefore, a SPL of 85 dB became a standard value in areas with no permanent working places, such as in noisy areas of power plants. Acoustic design in a power station must be handled thoroughly, consistently, and competently. To achieve an optimum solution the plant must be treated as a whole. Knowledge is needed of the processes within power station systems, the components, and their acoustic characteristics, as well as of architectural acoustics, and thermoacoustics. The redevelopment of the cogeneration power station ‘‘Berlin Mitte’’ is used to illustrate the acoustic engineering for a project with stringent indoor requirements. The approach used, noise reductions needed, and noise controls selected are reviewed. The requirement of a level of 85 dB in the near field was achieved. One special highlight was the steam turbine by-pass system, for which the standard design causes 98–108 dB.