3D Turbulent Flow Simulation And Study Of Flow Condition In Centrifugal Pump With High Temperature And High Pressure

In the nuclear plant, the effect of Steam Generator is to translate theengrgy from the reactor into the steam which drives the steam turbine to rotate.The Steam Generator is feed by feedwater pump, which works in the hightemperature and high pressure conditions. Presently, The study about the flowcondition in pump with high temperature and high pressure is so seldom that itis meaningful to research it.In this paper, the nixed flow pump with high temperature and highpressure is taken as research model. Establish the whole3D geometry fromthe inlet to the outlet, adopt structured mesh to divide the flow passage in theinlet pipe and unstructured mesh to other components of pump, and thenvarious speed sliding mesh technology is used to exchange interface flowinformation. Through the compare with experiment results, the RNG k-εturbulent model is adopted to perform steady and unsteady calculation ofmixed flow pump to analyze the flow condition.After steady simulation, analyze the influence of balancing holes on theperformance of pump and study the mechanism to reduce the axial forceacting on the shaft. Also, the flow condition in the seal ring which is betweenthe impeller and diffuser and likes the bio-honeycomb shape will be simulated.After finishing the unsteady simulation, the mechanism of generation andtransmission of main pressure fluctuation， the location of the source ofpressure fluctuation and the feature of amplitude are all gained. Whenanalyzing the amplitude of pressure fluctuation of recording points set on thewall of casing to prospect the safety, it is found that the amplitude of theserecording points have little influence on the safety of casing.Since the shape of casing is designed into spherical shape, the efficiencyloss of water in the casing is large. In this paper, the flow condition in thecasing is analyzed carefully to find the mechanism of efficiency loss. It can be found the flow condition is so turbulent that they are so many vortexes in theflow passage of casing. Also the water in the casing would repeat for severalcircles before go out from the discharge pipe. In the area of throat, appear alarge area of low pressure and bake flow. All of these cause the efficiency lossin the casing.