Evaluation of Proposed ASME Performance Test Code 36 for Sound Power Level Determination of Large Steam Turbine-Generators

The “two-surface” correction technique, as it is outlined in ASME Performance Test Code No. 36, is utilized in the determination of large steam turbine-generator sound power level (PWL). Test data obtained from using this method and other PWL calculation methods are presented. The two-surface method did not yield consistent results in the indoor environments encountered and had only limited application in turbine-generator PWL calculations. A modified two-surface approach was also tested. This method, which treats each component as a separate source and uses grids located close to the machine, was found to produce more accurate and confident results.