Research On Supercritical Thermal Power Labyrinth Controlvalve’s Fluid Field And Safety Characteristics

Boiler Soot Blowing System (BSBS) is an important part of a thermalpower unit. Pressure reducing station, which is consisted by pressurereducing valves and control device, is a key equipment of the BSBS. Toreduce the vibration and noise caused by high speed fluid, the Labyrinthcontrol valve (LCV) with larger resistance is preferred. The core componentof LCV is labyrinth disc, the labyrinth channel of it has an great impact onfluid field and safety. To solve the design problems in the LCV localization,this paper investigates the safety of LCV, the influence of key parameters oflabyrinth channel on its fluid field and safety. This paper mainly investigatesthe following sections:Firstly, to investigate the valve’s safety at high temperature andpressure condition, the valve’ temperature was calculated by CFX based onheat transfer theory and FEM. The valve’ stress field was calculated basedon theory of elasticity, the stress of valve body, cap, cage and plug wasanalyzed based on pressure vessel design by analysis and equivalentlinearization method. Suggestions were proposed for those parts whichdidn’t meet safety requirement.Second, to investigate the labyrinth channel structure’ influence onfluid field, based on fluid dynamics and shear stress transport turbulence(SST) model, the labyrinth channel’ fluid field at atmospheric pressurecondition was calculated and compared to experimental data, so that themodel and method was verified to be correct. The fluid field at actualcondition was calculated based on homogenous model and steam’s properties provided by international association for the properties of waterand steam. The influence of channel’s chamfer radius, channel depth, inletwidth and outlet width on fluid field was got by the research.Finally, to investigate the labyrinth channel structure’ influence on disc’safety, the labyrinth disc’s stress field is calculated analyzed by one wayfluid structure interaction. The influence of channel’s chamfer radius, discdepth and inlet width on disc’s stress field was got by the research, the rangeof parameters’ variation when disc was safe was given.