Two-phase flow holdup measurement method based on electromagnetic eddy current detection

Abstract

The invention provides a method for measuring phase holdup of two-phase flow based on electromagnetic eddy current detection. The device used includes an electromagnetic coil, a signal generating unit, an excitation circuit unit, a detection circuit unit, a phase detector and a flow parameter calculation unit; the electromagnetic coil It includes an excitation coil and a detection coil wound on the outer wall of the pipeline; the signal generating unit is used to generate an alternating sinusoidal current signal, and the signal generated by it excites the excitation coil through the excitation circuit unit; the detection circuit unit uses It is used to measure the voltage signal at both ends of the detection coil; the phase detector is used to detect the phase difference between the excitation signal of the excitation coil and the voltage signal of the detection coil obtained by the detection circuit unit, and the detection result is sent to the flow parameter calculation unit; the flow parameter calculation The unit calculates the phase holdup of the two-phase flow according to the phase difference detection result of the phase detector. The invention obtains the two-phase fluid phase holdup in a non-invasive manner without pre-separation or mixing of the measurement fluid.

Description

technical field [0001] The invention belongs to the technical field of fluid measurement, and relates to a measurement method based on the principle of electromagnetic induction and eddy current detection, which is used for non-contact measurement of phase holdup of oil / water and gas / water two-phase flow. technical background [0002] Multiphase flow phenomena widely exist in modern industrial production and daily life. Multiphase flow in pipelines often occurs in modern engineering fields such as power, nuclear energy, chemical industry, petroleum, pipeline transportation, medicine, food, etc. Accurate measurement of flow process parameters is helpful for the safe operation of related equipment. It plays a very important role in production and scientific research. Due to the interface effect and relative velocity between the phases in multiphase flow, the phase interface changes randomly in time and space, resulting in the flow characteristics of multiphase flow being far ...

AI Technical Summary

Problems solved by technology

The conductivity method calculates the phase-separation holdup by measuring the mixed conductivity of the two-phase fluid, but it is not suitable for the case where the non-conductive medium is a continuous phase; the capacitance method calculates the phase-separation holdup by measuring the mixed permittivity of the two-phase fluid, but in the Significant decrease in sensitivity occurs at higher conductivity of phase flow continuous phase

In addition, the change of medium conductivity in actual production brings disadvantages to these two measurement methods

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