Research On The Balance Arm Buffer Device Of Nuclear Power Plant Polar Crane

Polar crane in nuclear power plant is a kind of bridge crane in hoisting and transportequipment.It is different from the common bridge crane working in straight line.And it is a kind of equipment that runs in a circular orbit above the reactor plant of pressurized water reactor.During the construction of nuclear power station,it is responsible for hoisting and installation of the pressure vessel inside the reactor,primary pump,reactor internals and all kinds of equipment.During the operation of the plant,it serves for disassembling and maintenance of the head cover of pressure vessel inside the reactor,control element drive mechanism,reactor core barrel and other equipment.Hoisting mechanism is used to realize the lifting function of load.The critical load carried by the hoisting mechanism may cause the release of radioactive elements,so its safety is very important and a single fault protection principle is required.In this paper,polar crane produced by Taiyuan Heavy Industry Co.,Ltd.is used as the research object.For the existing lifting mechanism wire rope balance arm device using polyurethane buffer when a rope accidental rupture of the system caused by the impact load is too large,the buffer stroke is too long.A kind of wire rope balance arm device adopting hydraulic cylinder buffer was designed to reduce impact load and buffer stroke.Two different wire rope balance arm buffer devices and their key components adopting polyurethane buffer and hydraulic cylinder were simulated by AMEsim simulation software,including balance arm,wire rope,hydraulic cylinder and flow explosion-proof valve,polyurethane bumper and other system modeling and simulation analysis.Through the hydraulic cylinder buffer device in the lifting of the articles at different levels,rope twisting and hydraulic cylinder diameter and other influencing factors were simulated and analyzed.The strain rate of the steel wire rope was tested under two working conditions of normal and single steel wire rope rupture respectively,and compared with the simulation results.The results of mutual verification provide an important theoretical basis and reference for the safety design of hoisting mechanism of the nuclear power plant polar crane.