Non-contact optical fiber device and method for measuring flows

Abstract

The invention provides a non-contact optical fiber device and method for measuring flows. The device comprises a sensing fiber mounted in a pipeline. One end of the sensing fiber is connected with a grating, an optical fiber, a circulator and a light source sequentially, and the other end is connected with the grating, an interferometer and the circulator. The method includes connecting the grating to two sides of the sensing fiber to form a sensing unit, allowing light emitted from the light source to enter the sensing unit from the front end, converting monitoring vibration acceleration into monitoring optical phase by the grating interferometric technique, performing demodulation processing on phase information by the phase carrier technique PGC (programmed gain control), and realizing non-contact flow monitoring. The device is free of contacting with fluid, interfering with the flow field and electrical measurement, safe and reliable, high in adaptability, and free of being interfered by electromagnet; continuous remote measurement is realized, influences by light fluctuation and temperature changes are eliminated, throttle pressure loss rarely occurs, energy is saved, flows of corrosive fluids can be measured, multi-point measurement can be realized, and the device can be applied in measurement processes with various flows.

Description

technical field [0001] The invention relates to an optical fiber flowmeter in the technical field of optoelectronic measurement, in particular to a device and method for non-contact optical fiber flow measurement. Background technique [0002] Flow measurement is an important basis for modern industrial production, especially in the petrochemical field. Flow measurement can provide extremely important information for oil and gas pipeline detection, dynamic monitoring of production wells, and oil production and transmission characteristics in complex environments such as anti-corrosion, explosion-proof, high temperature and high pressure. parameters. The measurement methods are nothing more than two categories: contact and non-contact. The existing contact and non-contact measurement methods, such as the throttling part of the throttling flowmeter, the turbine of the turbine flowmeter, and the electrode of the electromagnetic flowmeter etc. This type of flowmeter has contr...

AI Technical Summary

Problems solved by technology

The measurement methods are nothing more than two categories: contact and non-contact. The existing contact and non-contact measurement methods, such as the throttling part of the throttling flowmeter, the turbine of the turbine flowmeter, and the electrode of the electromagnetic flowmeter etc. This type of flowmeter has contributed to flow measurement, especially to the flow measurement of oil production and transmission, but it also has the following shortcomings or deficiencies: ① the sensing element of the flow meter is in contact with the measured fluid, and The detection element in contact with the fluid will not only cause pressure loss, but also destroy the original flow field of the pipe flow; ② Generally, it is permanently connected to the system and can only measure the flow of a fixed part; ③ The sensing element of the flow meter itself is easily affected by the fluid Impact, wear, and even corrosion; ④Inconvenient installation and disassembly, easy to cause leakage and damage during installation and disassembly

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