Mechanics Analysis On Upender Of Large Pieces And180°Upender Scheme Design

Nowadays, domestic large-scale nuclear island equipment and hydrogenation reactorwith various key core technologies has been established, which are connected by welding ofsections named overall cap, big cylinder, cone-shaped transition section, thick pie, domehead and so on. Most of these parts have complex structures and each weighs up to300tonswith its diameter up to6700mm and axial length up to5400mm. That leads the displacementprocess of parts attitude of the vertical lathe machining, welding and assembling, NDT andother manufacture processes to be an important limiting factor restricting the productivityimprovements and workpiece surface quality improving, However, the research anddevelopment of upenders for nuclear power large parts is seldom reported no matter indomestic or abroad. This upender designed in June2013is the first example ever to beapplied in production. It costs nearly10million and is currently in the step of final assembly.In this situation, accurate theoretical analysis and calculation will be essential for theoptimization of equipment structure and the first trial operation, so the topic of this paper isof great significance.This paper carries out its research according to the project of nuclear large piecesupender funded by the China first heavy industries company. With the application oftheoretical analysis and dynamic simulation, we calculated the180-degree shift process of300tons workpiece. Then the complex stress state of the upender dangerous sport node andthe torque dynamic value of the main drive chain wheel are analyzed. Also, the impact on themain drive chain wheel due to barycenter changes of the upender vehicle is analyzed.Moreover, we evaluate the safe operation performance of the upender vehicle. Finally, westudy and formulate the turning solutions for tube sections and pipe plates in differentspecifications which are2800mm-6700mm in the radial size and135mm-2500mm in theaxial length.Based on the results of dynamics analysis, we analyze the maximum stress fields of thedangerous sport nodes with limit load via method of finite element software ABAQUS andpropose optimization advice to ensure the safety of equipment. The fatigue life of chain transmission system is predicted with fatigue analysis theory. Then we evaluate thesafety and reliability of upender to realize the180-degree shift of300tons workpiece for thefirst time and so do the rationality of structure design.Finally, this paper proposes a novel upender scheme which can realize a180°turning ofthe tapered transitional section, the dome head, the special thick pie and the shorttube. Theanalysis of the key dynamics parameters in the equipment operation is presented and theadvantages and disadvantages of the former upender and the new one are compared, whichdemonstrates the feasibility and practical value of this scheme.