Steam Turbine Noise

The heavy demand for electrical energy has required turbomachinery manufacturers to design and build steam turbine‐generator units which can produce over 1000 MW. Based upon numerous field surveys and experimental programs conducted in the laboratory, this paper identifies the major sources of sound produced by large fossil and nuclear steam turbines. Basic differences in operation between the two types of machinery are explained. Typical sound spectra are reviewed and measurements are used to show how the sound level varies as a function of such parameters as rotor unbalance, unit size and load, steam flow, and structural resonances. Basic sound mechanisms are discussed and general guidelines are given for designing quiet steam turbines, including such components as valves and piping systems. Additional measurements show that the sound level on the main turbine floor depends not only on the sound radiation characteristics of the turbine‐generator unit, but on the building architecture and plant layout. Measurement problems associated with predicting steam‐turbine sound levels are also discussed.