Method and device for measuring multi-channel ultrasonic flow

Abstract

The invention discloses a method and a device for measuring multi-channel ultrasonic flow-. Transducers which are twice as many as sound channels are mounted on a pipe section; every two transducers are connected with each other to form a sound channel; included angle of the sound channels and an axial line of the pipe section ranges from 15 to 75 degrees; a pressure sensor is placed at the front end of the pipe section; distances from the pressure sensor to the centers in the axle directions of all sound channels are the same; the sound channels corresponding to the transducers are divided into chordwise sound channels and radial sound channels; three or more than three chordwise sound channels are projected onto a cross section in the axial direction as a polygon. According to real-time detection of flow field pressure through the pressure sensor, a variance value and an initial value of the flow field pressure in one cycle are compared, and further time interval of flow measurement is increased or reduced, as a result, real-time adjustment of multi-channel measurement time interval is realized, and the method and the device are specially suitable for occasions of violent change of the flow field. Each sound channel comprises a radial sound channel and chordwise sound channels; and when obtained two speeds are compared, whether current state of the flow field is laminar flow or turbulent flow can be judged.

Description

technical field [0001] The invention relates to a flow measurement method and device, in particular to a multi-channel ultrasonic flow measurement method and device. Background technique [0002] Ultrasonic flowmeter is a kind of measuring instrument that uses the signal modulation effect of fluid flow on ultrasonic pulse or ultrasonic beam, and obtains volume flow by detecting the change of signal. The measurement principles of ultrasonic flowmeters can be divided into time difference method, Doppler method, beam offset method, correlation method and noise method. What this patent is aimed at is an ultrasonic flow measurement method using the time difference method for measurement. This flow measurement method can measure common liquids, gases, etc. [0003] In the process of fluid transmission, it is inevitable to use devices such as sudden expansion pipes, single bend pipes, double bend pipes, shut-off pipes, valves, etc., which will cause unstable flow fields such as e...

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Problems solved by technology

Due to the possibility of eddy currents or sudden changes in the flow field, the measurement intervals between the channels of the above two schemes are fixed, but in the case of sudden changes in the flow field, the flow field conditions in which each channel is measured are quite different , which in turn leads to a large deviation between the measured results and the actual flow field

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