Reliability And Stability Study Of Control Valve For Offshore Floating Nuclear Power Plant

In recent years,with the rapid development of offshore floating nuclear power plant,higher requirements have been put forward for the systems of nuclear power plants.The control valve is an important part of the offshore floating nuclear power plant piping system.It is necessary to meet both nuclear power standards and ship standards.During the use of the floating nuclear power plant control valve,the control valve not only has to bear the influence of internal pressure impact load,but also has to bear the influence of external rocking load,which leads to the lack of reliability and stability of the control valve,and poses a great safety risk to the offshore floating nuclear power plant.This paper takes a conventional industrial control valve applied to the floating nuclear power plant piping system as an example to study the structural strength and fatigue reliability of the floating nuclear power plant control valve under the two working conditions of high temperature pressure impact load and high temperature pressure and swing load.The main research content is as follows:(1)Introduced the research background and significance of the control valve for offshore floating nuclear power plants,and investigated the research progress of pressure shock,rocking and multi-field cooperative coupling at home and abroad,and the necessity of studying the structure strength and reliability of control valves under the condition of pressure and swing load is put forward.(2)Based on the Eulerian method,the three-dimensional model of the control valve was established by using Solidworks software.Using CFD Fluid Mechanics Simulation Software,the time domain information of pressure pulsation under different opening conditions of the control valve of floating nuclear power plant is analyzed,which laid the foundation for the numerical simulation of structural strength and fatigue reliability.(3)Based on the stress-strength interference theory,a reliability model for the control valve of a floating nuclear power plant was established,and the steady state thermal transient flow and structural coupling simulation of the control valve under high temperature and high pressure was performed.The structural strength and fatigue reliability of the valve body of the key parts of the control valve were analyzed.The results show that the impact of the same opening on the structural strength and fatigue reliability of the valve is less,but with the increase of the opening,the maximum stress value first increases rapidly and then gradually decreases,and finally tends to stability.that is,the pressure shock at high temperature has a great influence on the structural strength and fatigue life of different open valve bodies.(4)Based on the theoretical basis of the swing numerical analysis and the results of hydrodynamic simulation calculation,the mathematical model of the nonlinear swing motion of the control valve is established.The structural strength and fatigue reliability of the control valve under the control of the high temperature pressure and rocking load of the control valve are analyzed.The results show that the swing load has a great influence on the structural strength and fatigue life of the control valve,and the impact of the swing load on the valve design must be considered.Based on the above theoretical basis and numerical simulation,the structural strength and fatigue reliability of the control valve of Offshore floating nuclear power Plant are studied,which provides reference for the analysis and design of valves used in Offshore floating nuclear power plants.