| Nuclear main pump is one of the most important components in nuclear reactor, whose main function is to make the coolant circulate, in order to take away the heat of nuclear reactor core. The third generation advanced nuclear power technology is applied to AP1000nuclear main pump, that is the passive pressurized nuclear power technology. Big flow flux, high reliability and low maintenance rate is the target for nuclear main pump. This paper is about the high efficient hydraulic model in big flow rate.This paper was based on the speed coefficient method to design the nuclear main pump. Compared with the speed coefficients chosen by foreign and domestic design, the short comings of domestic nuclear main pump design could be found, by revising domestic velocity coefficient table, making it suitable for the nuclear main pump design. The efficiency of the preliminary impeller was89.51%using numerical simulation, which was too low to redesign. On the basis of preliminary design, boundary vorticity dynamics was used to diagnostic the blade. At a guarantee of axial size, impeller inlet shape and back arc profile were changed to improve the efficient to94.34%. The grid independence was used to validate the improvement impeller, and different turbulence models were employed to predicate the numerical accuracy.Because of the unknown inlet and outlet angle of the AP1000nuclear main pump, for the sake of the optimized inlet and outlet angle, Kriging optimization algorithm was introduced to change the both angle at a guarantee of axial size, in order to reach the optimized result. The optimization was obvious, because the efficiency was increased to95.56%.Based on the previous study, the diffuser and volute were designed to discus. Different guide vanes number, inlet angle, as well as the guide vane inlet condition were considered to examine the overall performance effect. Guide vanes number and inlet angle make little influence for the pump hydraulic performance, besides hydraulic performance of the guide inlet side parallel to the axis was better than that of the guide inlet side parallel to the impeller outlet side. Moreover the emphasis was placed on the design of the volute outlet place, it’s found that the hydraulic performance of side outlet volute was better than that of center outlet volute. For a whole modeling, by analyzing overall variable working condition performance, the maximum efficiency was in design flux, and the head declined with flux and didn’t appear hump. Besides it’s important to consider the effect of tip leakage flow in nuclear main pump. For the safety and stable operation condition, it’s useful to analysis the pressure fluctuation and radial force cased by the rotor-stator interaction. The radial force of x and y directions was only connected with the working frequency, and was rarely related to impeller and guide vanes. The impeller and guide vanes both affected each other. There’s fluctuation frequency in the impeller caused by guide vanes, and the same in the guide vanes. There’s great different between steady and unsteady condition in big flux, and little different in small flux and design flux condition.The research results presented in this thesis may provide some guidelines for the design and optimization of the nuclear main pump, which would be the foundation for the future research. |
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