Mechanical Analysis And Chassis Structure Optimization Of Lift Positioner For RRA Pump Maintenance

The residual heat removal pump(RRA pump)is a nuclear secondary pump.The decay heat brought out of the core after normal shutdown and accident shutdown is an important guarantee for the safe shutdown of nuclear island in nuclear power plant.There are six nuclear power units in Qinshan Phase II and Fangjiashan nuclear power plants,each of which has two RRA pumps.During each overhaul,one RRA pump needs to be disassembled and overhauled.In the process of overhaul,the pump needs to be overturned and displaced many times to find the appropriate station posture.At present,the operation is carried out in the way of car lifting and manual operation,which requires more manpower,and the efficiency is relatively low There is a potential risk of nuclear radiation pollution caused by long-term and frequent contact with RRA pump.In order to reduce personnel input,reduce labor intensity and improve the working environment,it is necessary to develop a lift positioner integrated with independent cantilever crane for RRA pump maintenance.First of all,according to the technical requirements of the equipment,through the functional analysis of the equipment,and through many discussions and demonstration of the equipment scheme,the final overall design scheme of the equipment is determined.On this basis,the main parts are selected,the lifting mechanism and displacement mechanism are designed,and the transmission chain is designed and calculated.In addition,the hydraulic system is designed and calculated on the basis of the research on the pressure output required for the interference fit between the coupling and the shaft.Secondly,the stability of the whole machine is evaluated and analyzed by using the torque balance method,and the three-dimensional model of the whole machine is created by using Pro / engineer software,which is based on ANSYS Workbench The platform carries out the finite element analysis of the chassis and key core components,and carries out the simulation analysis and verification of the structural strength of the equipment in many aspects,including but not limited to the structural static analysis and modal analysis,so as to ensure that the equipment structure meets the requirements of safety,reliability and stability before the manufacturing of the engineering prototype.Then,taking the equipment chassis as the research object,the structural optimization and lightweight design of the chassis are carried out in the design exploration module.The objective function is set as the chassis mass and the weight.The parametric driving and solution are carried out by using ANSYS Workbench,and the thickness of the chassis main bottom plate is taken as the design variable for optimization,so as to achieve the purpose of lightweight.Finally,the final configuration of the equipment is determined based on the initial design and optimization results,and the equipment manufacturing,installation,commissioning and trial operation are completed.