Optical-array-image fuzzy detection method for interfaces of oil, water and emulsion layer in large oil storage tank

Abstract

In order to reduce the detecting errors of a large oil tank and enhance the reliability of the detecting result, the invention discloses an optical-array-image fuzzy detection method for interfaces of oil, water and an emulsion layer in a large oil storage tank. The method comprises the following steps of: isolating and protecting optical fiber array ports by utilizing anticorrosive glass and sleeves; transmitting optical signals remotely by multi-path optical fibers; by liquid isolation in the oil tank, receiving the optical signals by optical fiber arrays, and remotely transmitting the optical signals to an analysis system; receiving optical signals with different intensities by adopting a group of linear arrays CCD, and judging the oil, the water and the emulsion layer by utilizing the optical transmission principle and the transmission difference of different liquid and adopting a fuzzy analysis method. Therefore, the optical-array-image fuzzy detection method disclosed by the invention has the advantages that not only is the visualization of detection realized, but also the direct contact of electric signals and fuel in a large-volume oil tank is avoided, so that the safety of system detection is improved.

Description

technical field [0001] The invention relates to an optical detection system for the interface of oil, water and emulsified layer, which belongs to optical technology and signal processing technology, and uses optical technology and image processing technology to realize the detection of the interface of oil, water and emulsified layer in an oil tank. Background technique [0002] Oil fields often use huge oil tanks for the final separation of oil and water, so that the oil and water are fully separated under the action of the demulsifier, and then the water at the bottom of the large oil tank is drained; if the water is not fully drained, the output product oil cannot reach the corresponding level. Index requirements; if the refined oil is discharged during discharge, it will cause economic losses; therefore, it is necessary to accurately detect the oil-water interface; the existing methods are divided into two categories: one is the detection of capacitance, pressure, magnet...

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Problems solved by technology

[0002] Oil fields often use huge oil tanks for the final separation of oil and water, so that the oil and water are fully separated under the action of the demulsifier, and then the water at the bottom of the large oil tank is drained; if the water is not fully drained, the output product oil cannot reach the corresponding level. Index requirements; if the refined oil is discharged during discharge, it will cause economic losses; therefore, it is necessary to accurately detect the oil-water interface; the existing methods are divided into two categories: one is the detection of capacitance, pressure, magnetic signals, etc., and the capacitive The detection principle is to use the overall capacitance of the measured substance to indicate the level of the liquid level. It is required that the ambient temperature, humidity and the composition of the measured medium itself remain unchanged. Under an open electric field, the capacitance is greatly affected by environmental factors. , the fluctuation of the capacitance value also affects the fluctuation of the output; in the past 10 years, the optical fiber detection method has been developed, such as document 1 ("Optical liquid level sensor (below)", Shi Jianjun, etc., Sensor World, Issue 10, page 14 The first line of the first column to the 12th line of the second column of the 15th page, 2002) provides the use of optical signals to detect the height of the liquid level, and realizes the detection of the interface between water and air in the case of light transmission in the container; Document 2 (CN101387538A ) discloses a linear array CCD transmissive liquid level measurement method and measurement device, which uses transmission to detect the liquid level height that can transmit light; these methods obviously cannot be used for oil, water, and emulsion layer interface detection in large oil storage tanks; currently The pressure detection and manual estimation methods are still used in engineering; the pressure detection method mainly relies on the distributed pressure detection method, and the oil-water interface is obtained after conversion; some oil fields also use the manual estimation method, and the error is larger; the principle of liquid level magnetic detection is to detect the drum The change of the magnetic flux between the components causes the output voltage signal of the electromagnetic sensor (Hall element) on the inner magnet to change, and its voltage value is compared with the stored reference voltage, and the float is adjusted to move up and down to reach the balance point again; the optical fiber detection uses infrared light In order to detect the light source, the optical fiber is used as the signal transmission carrier, and the optical fiber sensitive probe is used as the detection unit. According to the different characteristics of oil and water, the refraction principle of light is used to realize the fixed-point monitoring of the oil-water interface; The above methods have engineering errors, and cannot visually judge the oil-water interface

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