Judgement of critical state of water film rupture on corrugated plate wall based on SIFT feature selection algorithm and SVM classification method

Abstract

As an essential steam-water separation device in the secondary loop of nuclear power plant, the steam-water separation efficiency of corrugated plate dryer plays a decisive role in the economic indicators and safety of a nuclear power plant. Thus the research on the internal steam-water separation mechanism is of extremely significant value and the flow characteristics of the free falling water film on the corrugated plate wall are the basis of the research on water film rupture. The phenomenon of water film rupture on the wall surface will have a great impact on the secondary carrying, gas-water separation efficiency and even the economic indicators of nuclear power plants. However, it is meaningful to define whether the water film has broken and the fracture criterion because the method of defining the water film breakdown by the naked eye is extremely unreliable and inaccurate. Therefore, this paper proposes a method for defining the critical point of water film rupture on corrugated plate wall by the application of the SIFT (Scale-invariant feature transform) feature selection algorithm and SVM (Support Vector Machine) classification method. The SIFT (Scale-invariant feature transform) algorithm is applied to obtaining the characteristic information of the wall water film rupture image when the airflow velocity in the flow channel of the experimental section of the corrugated plate captured by the high-speed camera is gradually increased. Meanwhile, the two-class model of SVM (Support Vector Machine) is used to classify water film images and define the critical point of water film rupture on the corrugated plate wall by training, detection and inversion. The results show that the algorithm based on SIFT feature selection and SVM classification method can well define the critical point of water film rupture, keep the certainty and consistency of the water film rupture determination benchmark, and avoid the introduction of human identification error. It greatly improved the stability of the measurement and provides a reference for the determination of the baseline of water film rupture.