Gas-liquid two-phase flow type recognition method based on digital graphic processing technique

Abstract

The invention relates to a gas-liquid two-phase flow pattern recognition method based on digital image processing technology, which is characterized in that the method uses a high-speed camera to gain the gas-liquid two-phase flow image in a horizontal pipeline under the different working conditions; the characteristics of invariant moment and gray level co-occurrence matrix of the image are extracted by the image processing technology; the characteristic fusion is implemented by using a rough set theory to reduce the characteristic dimensions, and the characteristic vector forms a flow pattern sample to implement the training for a support vector machine in order to complete the mapping from the characteristic space to the flow pattern space and finally realize the flow pattern recognition. The adopted rough set theory fuses image texture information and shape information, improves the recognition precision of a classifier, simultaneously reduces the training time, and can roundly reflect the characteristics of flow pattern image; the dependent degree and the generalization capacity of the flow pattern recognition method of the support vector machine for the sample data are better than the BP neural network; the invention has the shorter training time, and is applied to the flow pattern online recognition.

Description

technical field [0001] The invention relates to the technical field of gas-liquid two-phase flow measurement, in particular to a flow pattern recognition method for gas-liquid two-phase flow based on digital image processing technology. Background technique [0002] At present, gas-liquid two-phase flow conditions are involved in many production equipment in industries such as power, chemical industry, nuclear energy, refrigeration, petroleum and metallurgy. The distribution of the phase interface of the two-phase flow medium, that is, the flow pattern, greatly affects the flow characteristics and heat transfer characteristics of the gas-liquid two-phase flow, and also affects the accurate measurement of the flow parameters and the operating characteristics of the two-phase flow system. The research on flow pattern recognition of liquid two-phase flow has always been an important research direction of two-phase flow parameter measurement, and it also provides strong technica...

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Problems solved by technology

However, since this method performs contact measurement on two-phase fluid, it will disturb the flow field, and at the same time, its application will be limited by the influence of measurement parameters in some high-pressure environments. Therefore, it is necessary to propose a fast and accurate non-contact flow pattern on-line Measurement methods

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