Analysis Of Hoisting Vertical Deflection Of Hook Block Of Polar Crane For Nuclear Power Plant

The polar crane for nuclear power plant runs on a circular orbit on the top of the reactor plant, lifts the pressure vessel cover and components for reactor, and the positioning accuracy of polar crane must be strictly controlled. The vertical deflection of hook block is a key factor affecting the positioning accuracy. The subject belongs to the scientific project of Liaoning province. The hoisting vertical deflection of hook block is a key technology of hoist equipment of the third-generation million-kilowatt nuclear power plant, and the research supports the theoretical reference for the arrangement of the hoisting mechanism and the balance winding of the wire ropes. On account of the facts that the static method ignores the dynamic characteristics of the model, and dynamics method only supports the approximate model of the simple ratio ropes, this paper integrates static and dynamic methods to research the hoisting vertical deflection. The main work is as follows:(1) The static model of hook block of polar crane is established and the hoisting vertical deflection analysis system is developed. Assuming the hook block is force balance in each height of hoisting, and the rope is equivalent to a direction of the force, the direction of the force is obtained by solving the space position of rope, the value of force is obtained by solving the tension of rope, as a result the force and moment balance equations are established. Combined with the conservation equation of the rope length and torque balance equation of pivot pulley, the balance equation of hook block system is established, and the mechanical model of hoisting vertical deflection analysis system of hook block is established, the analysis system of hoisting vertical deflection of hook block of polar crane is established on MATLAB platform to analyze the influence of the rope winding style, lifting height, lifting weight, working conditions on the running track and the vertical deflection of hook block.(2) The dynamic model of hook block of polar crane is established. The solid models of hook block of polar crane are built in Pro/E software, then imported into ADAMS/View. The dynamic winding model of wire rope is established in ADAMS/View with the bushing method, and dynamic simulation of vertical deflection is conducted. The initial equilibrium position of the hook block is obtained to analyze the influence of lifting weight, lifting speed on running track and the vertical deflection of hook block.(3) The typical cases are analyzed with static and dynamic methods. Static analysis results show that the vertical deflection of symmetrical arrangement of pulleys is smaller. the vertical deflection has a increasing relationship with lifting weight, comparing with the lifting situation, the vertical deviation of falling situation is smaller and in the opposite direction. and the effect of lifting weight to vertical deflection is not obvious. Dynamic analysis results show that dynamics analysis results have consistent trend with static equilibrium analysis results, only in fluctuation. The static analysis can be approximately resulted from the connection of the fluctuating peaks of displacement in wire ropes winding plane. For the displacement along roll axis, the results of dynamic analysis fluctuated around zero.