Continuous alternating magnetic field measuring device and method

An alternating magnetic field and measuring device technology, which is applied in the field of flow and concentration measurement in the process of dredging medium transportation, can solve the problems of poor real-time and authenticity of signals, inconvenient use, abnormal jitter, etc., to eliminate power frequency interference and improve Precise, easy zoom-in and transition effects

Pending Publication Date: 2020-12-08
CHANGJIANG WUHAN WATERWAY ENG CO
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, when this excitation method is used to measure the liquid-solid two-phase fluid in which the dredger is located, there will be slurry noise with spike-like pulse interference, resulting in abnormal jitter during flow velocity measurement, and this spike cannot be implemented by hardware means. Elimination, in order to improve the measurement accuracy, it is necessary to use software adjustment means, and adjust the excitation frequency
This limits the use of low-frequency square wave excitation on dredgers. First, the mud content and medium conditions in different construction sites are completely inconsistent. When a construction ship moves to different construction sites, it is necessary to adjust the frequency of the electromagnetic flowmeter. Convenience; moreover, when using software methods to filter and smooth peak pulses, the longer the filtering time constant and the higher the smoothing degree, the worse the real-time and authenticity of the signal

Method used

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  • Continuous alternating magnetic field measuring device and method
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  • Continuous alternating magnetic field measuring device and method

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Embodiment 1

[0039] Such as figure 2 As shown, a continuous alternating magnetic field measurement device of the present invention includes a measuring tube, an excitation coil, a sensor, an excitation source, a signal processing circuit and a controller.

[0040] sensors such as figure 2 As shown, the measurement electrode pair is fixed on the measurement tube through the tube wall along the diameter direction of the measurement tube, and the measurement electrode pair is represented by measurement electrode 1 and measurement electrode 2; in actual operation, the excitation signal is applied to On the excitation coil, a continuous alternating magnetic field is established on the inner wall of the measuring tube, and the electromotive force is measured on the measuring electrode pair to obtain the flow information of the pipeline.

[0041] Excitation source, most of the current electromagnetic flowmeters adopt low frequency square wave excitation method, its main feature is that it can ...

Embodiment 2

[0057] Since Embodiment 1 adopts the power frequency AC excitation method to excite the electromagnetic flowmeter, its sampling signal is continuously a curve, and the signal acquisition speed is very fast. The hardware device cannot be eliminated. Therefore, in order to solve the above problems, this embodiment provides a continuous alternating magnetic field measurement method, which includes the following steps:

[0058] S1. The AC excitation signal output by the power frequency AC excitation source is applied to the excitation coil, and a continuous alternating magnetic field is established on the inner wall of the measuring tube. The signal processing circuit described in Embodiment 1 is used to collect and process the measured electromotive force on the measuring electrode pair and the power frequency AC. The AC excitation signal output by the excitation source, and the processed signal is output to the controller;

[0059] S2. The controller receives the signal output b...

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Abstract

The invention provides a continuous alternating magnetic field measuring device. A power frequency alternating current excitation mode is adopted, and the polarization influence on the surface of an electrode can be eliminated; because the power frequency alternating current signal is a continuous signal, the established magnetic field is a continuous alternating magnetic field, the sampling speedis high, and the acquisition result is only related to the flow; the measuring device is suitable for construction sites with different medium conditions, and the excitation frequency of the electromagnetic flowmeter does not need to be adjusted; the output electromotive force of the electrode is measured in a power-frequency alternating-current excitation mode, is very easy to amplify and convert and is easier to process compared with a direct-current signal; a first instrument amplifier performs amplification and noise suppression processing on an output signal of an electrode signal conditioning circuit, and the processed electromotive force is subjected to phase compensation and zero compensation through a first phase sensitive detector, so that orthogonal interference signals and in-phase interference in the electromotive force can be eliminated, and flow signals and interference signals can be correctly distinguished.

Description

technical field [0001] The invention relates to the technical field of flow and concentration measurement in the dredging medium conveying process, in particular to a continuous alternating magnetic field measuring device and a method thereof. Background technique [0002] The measured medium of the electromagnetic flowmeter used on the dredger is a liquid-solid two-phase fluid (mud, even solid particles such as large stones). First of all, the DC excitation method that is only suitable for measuring liquid metal is excluded. At present, most domestic electromagnetic flowmeters adopt low-frequency square wave excitation, mainly because of its low excitation power consumption, good zero point stability, little influence of electrode pollution and no power frequency interference of AC excitation. However, when this excitation method is used to measure the liquid-solid two-phase fluid in which the dredger is located, there will be slurry noise with spike-like pulse interference...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): G01F1/58G01F1/60G01F15/02
CPCG01F1/588G01F1/60G01F15/022
Inventor张晏方余海胜胡滨周运其周游熊强陈玉芳吴友铿高玮龙杜鹃
OwnerCHANGJIANG WUHAN WATERWAY ENG CO