Study on Leakage Model of Typical Penetration of Closed Structures Based on Porous Media Seepage Theory

Xin Lin,Zhehua Du,Muhammad Afzal Rana

doi:10.1155/2022/6901534

Abstract

Quantitative prediction of penetration leakage rate has not been reported so far. The theoretical prediction method of leakage rate of typical penetration static seal structure of closed structure is studied. Based on porous media seepage mechanics, the relationship between leakage rate and microstructure parameters is established, and a new prediction model of the leakage rate of sealing structures is proposed. Then, the relationship between seal-specific pressure and microstructure parameters is obtained by the Hertz contact mechanics model. Finally, the leakage rate calculation, which is independent of any experimental data, is obtained innovatively. The new model is used to predict the leakage rate of penetration, and the theoretical prediction results are compared with the experimental measurement results. It is proved that the two agree well, which verifies the effectiveness of the model. The prediction model based on this method can well reflect the effects of rough surface morphology, material mechanical properties, sealing load, high temperature, and high pressure on the leakage rate. The leakage rate prediction model proposed in this paper is independent of the experimental regression coefficient and can realize the conversion relationship between different sealing media, sealing materials, and working conditions.

Highlights

Nuclear power plant containment is a typical closed structure. e pressure boundary formed by the containment and much perforated equipment, components, and pipelines penetrating the containment is the last barrier between the internal equipment or system and the environment and a very important barrier related to safety
Penetration can be divided into electrical penetration and mechanical penetration. e principal function of the electrical penetration assembly is to connect the electrical equipment to the outside of the containment to control the equipment inside the containment. ere are two types of mechanical penetration: one is fuel transportation penetration; the other is mechanical pipe penetration
The accuracy of the prediction model is verified by experiments. is method can effectively analyze the coupling effect of interface microstructure and material macromechanical properties on the leakage rate

Summary

Introduction

Nuclear power plant containment is a typical closed structure. e pressure boundary formed by the containment and much perforated equipment, components, and pipelines penetrating the containment is the last barrier between the internal equipment or system and the environment and a very important barrier related to safety. E focus is to establish the quantitative relationship between microfine structure and macromeasure and put forward a prediction and calculation method of leakage rate independent of experimental regression parameters On this basis, the accuracy of the prediction model is verified by experiments. Is method can effectively analyze the coupling effect of interface microstructure and material macromechanical properties on the leakage rate It provides a theoretical basis for the development and design of penetration seal structure and provides guarantee for environmental quality and safety. Q Φσ · Φh · Qp. Formula (6) effectively reveals the flow characteristics of gas in the sealing interface, and it offers an effective way to build the interface leakage mechanism model based on the numerical calculation method. Taking the manhole pressure cover as an example, the penetration leakage theoretical model of typical structures is constructed [4–7]

Finite Element

Quantitative Prediction of

Conclusion