Stress Analysis Of Canned Nuclear Coolant Pump Based On Rotor-stator Interaction Effect

The reactor coolant pump (RCP) is one of the most importantcomponents in nuclear power plants.It operated in hightemperature,high-pressure,high speed and radiative environment,so along-term security and reliable operations is required.Many internal flow analysis of RCPs was carried out，mainly foucson steady and unsteady flow field at different operating points inRCP.The research about flow passage components,such as the blade ofthe RCP,is relatively few.When the RCPs operates in the nuclear powerplant,the flow field lashed against the impeller of the RCP,results in anetwork of small cracks is found on the surface of impeller.Forexample,periodic vibration caused by a break in a guide vane leaded tocracking of two pieces blades of impeller in a large power plant insouthwest of China,and this accident caused much economic loss.As aresult，this paper does following studies focus on the unsteady flow fieldin nuclear coolant pump and the impeller stress which influenced by theunsteady flow field.In this paper,the model of nuclear coolant pump which includes thecase,guide vane,impeller,inlet and outlet is established.The CFD mehod is used to simulate the pump performance.By the comparison of thesimulation result and the experimental result,the accuracy of the hydraulicmodel is comfirmed.The the unsteady simulation of the model pump isconducted to abtain the characteristic of the unsteady flow field and thepressure fluctuation induced by the rotor-stator interaction in the pump.The computational method of stress due to the hydraulic reason is animportant problem of the RCP. In this work,the CFD simulation includingthe case,guide vane,impeller,inlet and outlet at different operation pointsis studied,and the result of the pressure distribution on impeller blade isloaded on the impeller using fluid-structure interation(FSI) method.Theresult showed that the maximum von Mises stress appears on the trailingedge close to the impeller hub which has a large change in gradient ofstress and which is prone to fatigue failure. The maximum stress on theimpeller is mainly in proportion to the operating power. The maximumstress on the impeller have periodical characteristic，which is due to thenumber of blade of diffuser.