A Method for Measuring and Correcting Liquid Film Thickness of Gas-liquid Two-phase Annular Flow in Circular Pipe

Abstract

The invention discloses a measuring and correcting method for gas-liquid two-phase annular flow liquid film thickness in a circular pipe. The method comprises the following steps: 1) photographing thephase interface of the gas-liquid two-phase annular flow in the circular pipe by a photographing device 1 through combination of a light source 3 so as to obtain a grayscale image including a liquidfilm and a gas core; 2) performing digital image processing on the grayscale image so as to obtain a binary image including the liquid film and the gas core; 3) extracting that gas-liquid phase interface information in the binary image so as to obtain the imaging value of the liquid film thickness; 4) establishing an optical imaging theoretical model for predicting the wall thickness of the circular pipe and the quantitative relationship between the imaging value and the real value of the liquid film thickness; and 5) correcting the imaging value h of the liquid film thickness to be measured by using the optical imaging theoretical model of the liquid film constructed in the step 4) so as to obtain the real value h of the liquid film thickness to be measured. According to the method, visual measurement of the liquid film thickness of the gas-liquid two-phase annular flow in the circular pipe can be realized so as to have higher detection accuracy, safety and reliability and low detection cost.

Description

technical field [0001] The invention belongs to the technical field of parameter measurement of gas-liquid two-phase annular flow, and in particular relates to a method for measuring and correcting the liquid film thickness of gas-liquid two-phase annular flow in a circular tube. Background technique [0002] Gas-liquid two-phase annular flow is an important and widely used two-phase flow in the engineering field. The annular flow in the pipe is mainly composed of the liquid film on the pipe wall and the central mist-like high-speed gas core. The liquid film on the pipe wall in the annular flow has a strong heat and mass exchange capacity, and the accurate measurement of the thickness of the liquid film plays an important role in the in-depth study of the flow and transfer characteristics of the annular flow. According to different measurement principles, the measurement methods of liquid film thickness mainly include acoustic method, conductivity method, optical method and ...

AI Technical Summary

Problems solved by technology

Optical method is currently the most widely used method, but optical measurement equipment is generally expensive, the operation process is complicated, and there are strict requirements on the cleanliness of the measured medium and the application environment

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