Electromagnetic flowmeter for non-full pipe flow measurement

Abstract

The invention relates to an electromagnetic flowmeter for non-full pipe flow measurement, comprising an electromagnetic flow transducer, an electrical impedance measurement module, an induced electromotive force measurement module and a control and signal processing module. The electromagnetic flowmeter is characterized in that the electromagnetic flow transducer comprises a measuring pipe, an electrode and a magnet exciting coil; the electrical impedance measurement module includes a multi-way switch group (A), an excitation signal source circuit and an electrical impedance measurement circuit; the induced electromotive force measurement module comprises a multi-way switch group (B), an exciting circuit and an induced electromotive force measurement circuit; and the control and signal processing module is in charge of controlling the multi-way switch groups, the electrical impedance measurement module is used for obtaining a plurality of groups of electrical impedance values, and the induced electromotive force measurement module is used for obtaining a plurality of groups of induced electromotive force values, so that the flow rate inside a pipe can be obtained under the conditions of full pipe and non-full pipe. The electromagnetic flowmeter can realize accurate measurement of the flow rate without calibrating different fluid mediums in a state of non-full pipe flow.

Description

technical field [0001] The invention relates to a flow measurement device, in particular to an electromagnetic flowmeter. Background technique [0002] At present, traditional electromagnetic flowmeters are generally sensitive to flow patterns, for example, the Chinese published patents of electromagnetic flowmeter CN1108385, electromagnetic flowmeter CN1131273, electromagnetic flowmeter and flow electromagnetic measurement method CN1097868, etc. The electromagnetic flow sensor is installed in the pipeline, and the conductive liquid flows through the electromagnetic flow sensor. The converter supplies the excitation current to the excitation coil to generate a magnetic field in the electromagnetic flow sensor, and the moving fluid cuts the magnetic field line measurement electrode to obtain the induced electromotive force. For the above structure, when any point of fluid micro-unit flows through a certain point in the measuring tube, the induced potential generated is not o...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above-mentioned defects in the prior art, the problem to be solved by the present invention is to provide an electromagnetic flowmeter that can be used for the measurement of the flow in a part-filled pipe, which solves the problem that the existing electromagnetic flowmeter is sensitive to the flow pattern in the measuring pipe, and in the case of a non-full pipe. Different fluid media need to be calibrated under the full pipe flow state, etc.

Images