Development of Advanced Ultrasonic Flowmeters
Purpose
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Flowrate is one of the fundamental quantity in industrial plants. It directly affects on the product quality and effective use of the energy.
Therefore, high accuracy flowmeters are desired. Ultrasonic flowmeters have been widely used. In transit-time ultrasonic flow meters (TOF), the flow rate is derived from the transit time of an ultrasonic pulse between two ultrasonic transducers.
To convert the transit time into flow rate, a profile factor (PF) is required. Because the PF strongly depends on the velocity profile, a precise calibration of the PF is essential to the accuracy of the TOF.
Hence, a field calibration, referred to as on-site calibration, is desirable.
In this study, a hybrid ultrasonic flow meter that helps calibrate the TOF using ultrasonic Doppler velocity profile method (UDV) has been proposed for on-site calibration by integrating the velocity profiles over the cross-sectional area of a pipe.
Furthermore, a new approach for clamp-on ultrasonic flowmeter has been developed for measuring the flow rates from outside of existing pipes.
Research content
| Fig. 1 Ultrasonic pulse Doppler velocity profiler |
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| Fig. 2 Velocity profile measured using UDV |
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| Fig. 3 TOF flowmeter |
Fig. 1 shows the schematic of the ultrasonic Doppler velocity profile method (UDV). In the UDV, ultrasonic pulses are emitted to the flow from an ultrasonic transducer.
The echo signals reflected by the ultrasonic reflectors seeded in the fluid are received by the same ultrasonic transducer that emitted the original signals.
A velocity profile along the ultrasonic beam can be obtained by analyzing the recorded echo signals. A system to calibrate the
Fig. 1 shows the schematic of the ultrasonic Doppler velocity profile method (UDV). In the UDV, ultrasonic pulses are emitted to the flow from an ultrasonic transducer.
The echo signals reflected by the ultrasonic reflectors seeded in the fluid are received by the same ultrasonic transducer that emitted the original signals.
Velocity profiles along the ultrasonic beam can be obtained by analyzing the recorded echo signals. Using the UDV, a hybrid ultrasonic flow meter that helps calibrate the TOF using the UDV was developed.
The system has been developed by ourselves. It comprises an ultrasonic pulser/receiver, a high-speed digitizer, and a PC. The measurement software is laboratory-made.
The two ultrasonic transducers are connected to the pulser/receiver. One transducer emits ultrasonic pulses and receives echo signals from the reflectors, and the other transducer receives the transmitted ultrasonic pulses.
The signals recorded using the digitizer are transferred to the PC. Thus, both the echo and transmitted signals can be simultaneously recorded.
Fig. 2 shows instantaneous velocity profiles measured using the UDV. For calibrating the TOF profile factors, the measurement accuracy of the TOF could be improved.
The error in measuring the flow rate along the three measuring lines using the UDV was within 0.3%, even installing the obstacle plate.
Furthermore, a new method for clamp-on ultrasonic flow meter has been developed
for calibrating the existing flowmeters (Fig. 3).
Publications
E. Muramatsu, H. Murakawa, D. Hashiguchi, K. Sugimoto, H. Asano, S. Wada, N. Furuichi
Applicability of hybrid ultrasonic flow meter for wide-range flow-rate under distorted velocity profile conditions, Experimental Thermal and Fluid Science 94 (2018), pp.49-58. https://doi.org/10.1016/j.expthermflusci.2018.01.032
E. Muramatsu, H. Murakawa, K. Sugimoto, H. Asano, N. Takenaka, N. Furuichi
Multi-wave ultrasonic Doppler method for measuring high flow-rates using
staggered pulse intervals, Measurement Science and Technology 27 (2016),
025303 (11pp). https://doi.org/10.1088/0957-0233/27/2/025303
H. Murakawa, E. Muramatsu, K. Sugimoto, N. Takenaka, N. Furuichi
A dealiasing method for use with ultrasonic pulsed Doppler in measuring
velocity profiles and flow rates in pipes, Measurement Science and Technology
26 (2015), 085301 (11pp). https://doi.org/10.1088/0957-0233/26/8/085301
E. Muramatsu, H. Murakawa, K. Sugimoto, N. Takenaka
A new method for high flow rate measurement using ultrasonic multi-wave
pulsed Doppler method with staggered trigger, Proc. of International Conference
on Power Engineering-15 (2015) #ICOPE-15-1040. https://doi.org/10.1299/jsmeicope.2015.12._ICOPE-15-_27
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