Apparatus for measuring flow velocity of fluids

摘要

Disclosed is an apparatus for overcoming acoustic path angle limitations and transducer coupling problems when an ultrasonic flow measurement method is used to measure water velocity in annular regions such as the downcomer of a nuclear steam generator. In accordance with one embodiment, two axially spaced ultrasonic transducers are coupled perpendicularly to the outer surface of a shell and align respectively with two 45 DEG reflecting surfaces on a structure which is inserted into the downcomer during shutdown. The acoustic path between reflecting surfaces is essentially in line with the fluid flow as desired for best sensitivity and accuracy. Acoustic performance is optimized and transducer mounting is simplified by having the transducers perpendicular to the shell surface. Other embodiments are disclosed for measuring the average flow velocity by angling the acoustic path across the annular region of the downcomer.