Research On Flow Characteristics Of Level Control Valve Of Water Storage Tank

In this research, the level control valve of water storage tank which is used inthe safe operation of ultra-supercritical thermal power boiler, has two regulatoryagencies of the spool and two orifice plates. This type of valves is easy to swirl inthe runner between the spool and the second flow passage orifice plates during thecourse of their work, which makes an impact to the inner wall of the valve body,reduces valve life, affects the overall safety of the unit and is the reason of noise andleak by long-standing. With the reason above, the research on flow characteristics oflevel control valve of water storage tank has a great significance. The study does theresearch of the internal fluid flow characteristics with CFD to improve the design ofthe flow channel structure and reduce vortex effectively. Thesis does the followingwork.Introduce the working principle of water level control valve of water storagetank, establish flow channel model in various stages of the open process bySolidWorks and establish mesh models in various stages of the open process byICEM CFD.For fitting the ideal flow characteristic curve of level control valve of waterstorage tank, flow resistance coefficient and flow coefficient, it does simulationanalysis of internal fluid flow characteristics with ANSYS CFX under the condition,which the inlet pressure is1MPa, Outlet pressure is0MPa and the fluid medium iswater. With the simulation analysis of the level control valve of water storage tankabout internal fluid velocity distribution under the actual working conditions, it getsthe fluid pressure loss condition and the vortex generated case in the runnerbetween the spool and secondary throttle plates. The simulation analysis of internalfluid flow with different openings provides the basis for the improved design offlow channel.For solving the flow field inside the swirl valve problem, it does theimprovement in internal structure of the level control valve of water storage tankwith the principle of expanding body cavity and reducing the inclination of the body wall boundary. Then, it does the simulation analysis of internal fluid flow under thefull opening after structural improvements and proves that the method basicallyeliminate or reduce the whirlpool.This paper provides a theoretical basis for the structural design of level controlvalve of water storage tank. Test and verify the feasibility of CFD numericalsimulation in valve design.