Reclamation Information Sharing Environment (RISE)

The Winter-Kennedy (WK) method of flow measurement correlates a difference in pressure at a cross-section of the scroll case to the discharge through the hydropower unit. Many of Reclamation’s hydropower units include pressure taps configured for WK measurements but few have been used. Utilizing an existing flow measurement system with their original calibration could provide a significant cost savings for flow measurement equipment and provide value for monitoring water quantities or even unit efficiency. Limitations of this method include changes to the condition of the interior pressure taps, penstock surface roughness, coating degradation, and many other factors that influence the calibration. The intent of this study was to determine the value of existing WK systems by comparing flow estimates from original WK calibrations to an absolute flow rate reference. Field tests were done on six different WK pressure tap systems at three Reclamation hydropower plants. Equipment and original calibrations were at least 40 years old for each unit tested. Test results showed that the original calibrations have drifted significantly and that for each case new calibration tests would be required for the flow predictions to be used.