Study On The Influence Of The Stiffness Of The Three-generation Nuclear Polar Crane Structure On The Accurate Position

The nuclear polar crane is a lifting and transportation equipment used to lift reactor equipment in nuclear power plants.Due to the particularity of its application,strict requirements are placed on the positioning accuracy of the suspension.The main beam structure of the trolley bridge is the core component of the ring crane in the nuclear polar plant,and it is also the bearing component responsible for bearing the small wheel pressure and it bears the role of the bridge connecting the circular orbit and the nuclear island.More than 60% of the crane's own weight comes from the main girder.The interior of the crane is composed of complex ribs.The rationalization of the main girder construction will have a great impact on the deformation of the girder and on the reduction of its own weight.At present,most of the domestic studies on nuclear hoop cranes focus on the calculation of life and seismic calculations.There is not much research on the structural stiffness.In this direction,the third generation of box-shaped solid-belt double-beam structure nuclear polar crane CAP1400 is taken as the object of study.The influence of its structural stiffness on the precise positioning is analyzed and studied,and the relevant research on the multi-objective optimization of the main beam is carried out.The main content of the thesis is as follows:(1)Taking the horizontal guide device as the research object,analyzing the force condition of the horizontal guide device,and verifying the force condition of the horizontal guide device by means of ADAMS multi-rigid body simulation.The results showed that the peak value of the elastic force generated during the process of the nuclear polar crane motion is the lateral force of the horizontal wheel.Under the same conditions,the horizontal guide device mainly provided lateral support,and the stiffness of the overall bridge had almost no influence on the positioning accuracy.(2)By establishing the mechanical model of the metal ring hanging metal structure,based on ANSYS,the finite element analysis of the nuclear ring suspension bridge structure under different combinations is carried out.The results showed that the effect of the bridge deformation on the precise positioning is small under the rated load conditions.(3)Applying Workbench to the multi-objective optimization analysis of the main beam structure.The eight dimensions of the rectangular section of the main beam are selected as the input parameters,and the sensitivity of the input parameters is compared with the lightest mass of the main beam and the maximum deformation as output parameters.The results showed that the bridge structure can effectively reduce the weight by at most 25.2% under the condition of satisfying the stiffness of the nuclear polar crane.Combined with the sensitivity analysis,it can provide a reliable and fast reference for the structural optimization design of the new nuclear polar crane girder.