ASSESSMENT OF STEAM LINE DYNAMIC PRESSURES USING EXTERNAL STRAIN GAGE MEASUREMENTS

摘要

Dynamic pressure measurements have been made at a number of power plants using externally mounted strain gages on piping in order to characterize structural loading of upstream piping and pressure vessel components. The pressure fluctuations are derived from the 'breathing' mode of the piping therefore this indirect technique must be robust enough to reject the effects of other shell modes and/or bending. Several factors influence the ability to ensure that the breathing mode response can be measured; these factors include strain gage configuration options and data processing methods. The tested strain gage configurations utilized up to eight strain gages per location in an axisymmetric manner to facilitate the handling of any shell mode responses that may exist. Data processing strategies utilizing channel combination and filtering techniques were designed to extract pure breathing mode data for conversion to dynamic pressure. This paper will evaluate the various approaches and identify the most reliable one for plant implementation.