Dual inside-and-outside ring capacitance sensor and two-phase flow speed related measuring system

Abstract

The invention which belongs to the fluid measuring technical field relates to a double inner and outer ring capacitance sensor for flow rate measurement, which comprises a measuring pipe, and two same capacitance sensors arranged on the upper stream and lower stream of the measuring pipe. The invention is characterized in that: cylindrical electrode carriers are fixed on the axle line of the measuring pipe, the two inner ring electrodes of the capacitance sensor on the upper stream and the capacitance sensor on the lower stream are respectively fixed outside the cylindrical electrode carriers, and the two outer ring electrodes of the capacitance sensor on the upper stream and the capacitance sensor on the lower stream are respectively fixed on the inner wall of the measuring pipe corresponding to the positions of the two inner ring electrodes. The invention also provides a two-phase flow correlation measurement system adopting the capacitance sensor. The capacitance sensor and the two-phase flow correlation measurement system can greatly eliminate the uneven distribution of the flow field and the electric field and improve measuring accuracy.

Description

technical field [0001] The invention belongs to the technical field of fluid measurement, and in particular relates to flow velocity measurement of gas-liquid, gas-solid, liquid-solid, liquid-liquid and other two-phase fluids. Background technique [0002] Two-phase flow refers to a flow system composed of two-phase substances (at least one phase is a fluid). If there are more than two phases of substances in the flow system, it is called multiphase flow. Two-phase or multiphase flow is the most common viscous fluid flow involved in the process of phase change, mass transfer and reaction in chemical production. Heat transfer with phase changes, gas absorption in column equipment, liquid distillation, liquid extraction, and chemical reaction processes in stirred tanks or bubble columns all involve two-phase flow. In the oil-gas-water three-phase flow measurement in the petroleum industry, the separation device is used to initially separate the fluid to obtain a two-phase flo...

AI Technical Summary

Problems solved by technology

Cross-correlation technology is currently a widely used method in measuring the flow velocity of two-phase flow. Due to the limitation of the principle of this method, there is a certain error between the obtained correlation flow velocity and the real flow velocity of the fluid, which affects the measurement accuracy.

[0003] The invention patent application with application number 200510045977.6 proposes a real-time detection device for solid-liquid two-phase flow capacitance based on capacitive sensors and related technologies. Although this method performs correlation analysis on the capacitance value and then performs corresponding processing, the device has the following Disadvantages: (1) It is only suitable for the measurement of solid-liquid two-phase flow (2) Without pretreatment of the fluid, the fluid flowing into the capacitive sensor may have a large speed slip (3) The capacitive sensor and capacitive detection method used in this method The accuracy of the circuit still needs to be improved

The invention patent with the application number 200510046171.9 proposes a two-phase flow velocity measurement method based on multi-sensors, cross-correlation of capacitance values ​​and ultrasonic cross-correlation analysis, although this method performs correlation analysis on the capacitance and ultrasonic values ​​before doing Corresponding processing, but it does not analyze the cause of the error in the two-phase flow velocity measurement of the related method, so it does not give a solution to the measurement error from the flow sensor part, and does not fundamentally solve the problem

In addition, the traditional capacitive sensor used to measure fluid flow velocity is composed of two semi-annular electrodes, the electric field distribution between the two electrodes is uneven, and the distribution of the flow field has a great influence on the flow velocity measurement

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