Secondary Software Development And Dynamic Response Analysis Of Main Pump Rotor System Based On ANSYS

Large shielded motor main pump,referred to as the main pump,is the key component of the advanced pressurized water reactor nuclear power plant.It is used to drive the coolant inside the primary circuit of the reactor to be recycled.And it is usually acknowledged as the "heart" of the reactor.A key issue in the development of advanced nuclear power plant is the design and manufacture of nuclear main pumps.The large-scale canned motor main pump consists mainly of a rotor,stators and seals.Among them,the rotor system is its core component.The dynamic response of the rotor system has direct effect on whether the main pump can run normally.The mechanical analysis of the main pump rotor system in the computer can provide reference for the design process of the main pump,thereby decreasing design errors and iterative processes and reducing the development cost.However,due to the complicated structure of the main pump,the high precision requirements for calculating the dynamic response of the rotor system,and the strict confidentiality of the key technology of the nuclear main pump,there is currently no mature method available for mechanical analysis of the main pump rotor system.Due to the above practical reasons,in this dissertation,the ANSYS software is applied to carry out two aspects of studies.Firstly,a secondary development of software program based on the APDL language of ANSYS is completed which includes two main calculation features:the main pump idling performance analysis and the main pump rotor dynamics analysis.The software is written in Pascal language and has an intuitive and easy-to-use interface.It is intended to help the relevant engineers to easily solve some common basic problems of the main pump.The software can achieve the required tasks sequentially from "generating the required command stream file" to"running ANSYS for calculation in the background’" and finally "displaying results".With this software,engineers no longer need to directly operate the relatively complex ANSYS,thereby improving research productivity.In the software,the idling performance analysis part mainly executes the calculation of the main pump inertia and the main pump idling characteristic curve.The rotor dynamics analysis part mainly calculates the critical speed,unbalance response and transient response of the main pump rotor.In the second aspect,the upper and lower radial sliding bearings inside the main pump rotor system are considered,and a database method which is feasible in the transient calculation is proposed.Compared with some commonly used approximate analytical formulas,the database method has the advantage of boundary conditions and liquid film distribution closer to the actual situation.The bearing force calculated by the finite difference method is regarded as the standard.The bearing forces results obtained by this database method are compared with the ones by several commonly used analytical equations.In contrast,it is shown that the present results are more accurate in most cases.Finally,under the design speed of the main pump,the transient response of the main pump rotor is simulated by the database method,and the obtained journal center amplitude is smaller than that by the Capone model.In conclusion,this dissertation carries out the work of simplifying the common basic problems of the main pump rotor system and establishing a more accurate bearing force model.The research can provide reference for the design and manufacture of the nuclear main pump and promote the formation of a more mature mechanical analysis method for the main pump rotor system.