In order to improve thermal efficiency and optimize plant operation at electric power plants, ultrasonic pulse Doppler method is being developed to attain the high accuracy in flow rate measurements. Ultrasound waves are emitted into fluid from ultrasonic transducer mounted on the outer surface of a pipe. Waves are bounced back at the surface of ultrasound reflectors flowing in fluid. By detecting Doppler shift frequency of those waves, velocity profiles along the ultrasound beam path can be obtained. Integration of those instantaneous velocity profiles gives us the flow rate in a pipe. In this report, the series of velocity profile measurements are summarized with field tests at an actual power plant for the downstream of an elbow with micro bubbles generated for ultrasonic reflectors.
