Three-dimensional Cavitation Simulation Of Condensate Pump Under Ocean Condition

Marine nuclear power plant has the advantages of strong endurance,such as independent of oxygen,large power,stable operation and easy control,etc.It has been widely used in military and civil applications.As an important part of condensate water supply in the secondary loop of Marine nuclear power plant,condensate pump plays a very important role in the safe operation of Marine nuclear power plant.As the space arrangement of the Marine nuclear power plant is limited,the pouring height of the condensate system is small,the condensate subcooling degree after deoxygenation is very low,and the condensate pump is in a saturated state,cavitation is easy to occur in the operation process of the condensate pump.In addition,under the influence of ocean waves during hull operation,the condenser liquid level of the condensate pump will fluctuate significantly with the rolling and pitching motion of the hull,which may induce cavitation of the condensate pump and affect the safety and stable operation of the Marine nuclear power plant.Therefore,it is of great significance for the safe operation of Marine nuclear power plant to analyze the operation characteristics of condensate pump under ocean condition and check whether the design of condensate pump meets the cavitation resistance performance requirements under bad working conditions.Taking the condensate pump as the research object,this paper uses the numerical calculation method to study the cavitation performance and cavitation flow characteristics of the condensate pump under 45? working conditions with the rolling cycle of 3s,and analyzes the internal flow field and cavitation evolution characteristics of the condensate pump under hostile environment.Carry out three-dimensional numerical simulation calculation for cavitation of the non-wobbling condensate pump,and compare the results with the zwart-Gerber-Belamri cavitation model applicable in this paper,and analyze the flow characteristics in the non-wobbling condensate pump.Three-dimensional numerical simulation was performed on the condensate pump with the rolling cycle of 3s and no cavitation under fluctuating conditions with the amplitude of 45?.The fluid flow characteristics of the condensate pump under fluctuating conditions within half the rotating cycle were obtained.In the half swing period,the overall pressure value in the rotation calculation domain increases first and then decreases with time.In addition,due to the existence of swaying conditions,vortices and flow separation are likely to occur near the working impeller blade,which will cause serious flow loss or even flow obstruction andseriously affect the normal operation of the condensate pump.It provides some reference for the 3d numerical simulation of cavitation of condensate pump under ocean condition.Three-dimensional numerical simulation of cavitation under fluctuating conditions with 45? was performed on the condensate pump.It was concluded that cavitation occurred in the guide wheel and first stage working wheel of the condensate pump.The cavitation phenomenon of the first stage working wheel appears at the blade inlet,which is not obvious and can be almost ignored.In this paper,the condenser pump regulating wheel is more prone to cavitation than other components under the rocking condition,so more attention should be paid to the cavitation resistance performance of the condenser pump in the later design of Marine nuclear power plant.