Method for manufacturing hot segment of bent pipe of main pipeline of reactor

Abstract

The invention discloses a method for manufacturing the hot segment of a bent pipe of a main pipeline of a reactor for a third generation of nuclear power station, which can meet the technical requirement of the reactor of the third generation of the nuclear power station to the pipe and guarantee the machining quality of a pipe mouth. The method comprises the steps of: A. preparing a combined type forming module which comprises an upper module, a lower module and a core module, wherein the core module is made from method, is formed by a plurality of blocks which are arranged along the axial direction, and leads the filling rate of the inner space of a filling pipe body of the core module to be larger than 95%, wherein the filling ratio is volume ratio of the volume of the core module and the inner space of the pipe; B. preparing a straight tubular pipe blank according to the structural shape of each part of the pipe body; C. mechanically machining the pipe blank and machining the inner hole and the outer periphery of the pipe body; D. filling the core module into the pipe blank, and putting the core module between the upper model and the lower module to be formed by means of pressing; and E withdrawing the core module, and mechanically machining the end faces of the two ends of the pipe body, as well as the end face, the inner hole and the outer periphery of the pipe mouth. The method can be used for manufacturing an intergraded large-sized pipe part with a straight pipe segment and a bent segment.

Description

technical field [0001] The invention relates to a method for manufacturing a hot section elbow of a reactor main pipeline for a third-generation nuclear power plant. Background technique [0002] At present, the third-generation advanced large-scale AP1000 pressurized water reactor nuclear power plant is the updated model of the second-generation nuclear power plant and the second-generation plus nuclear power plant in the world. Its main advantages are that its service life has increased from the previous 40 years to 60 years, and the installed capacity of a single nuclear power plant has reached 1.25 million kilowatts. Due to the improvement of technology, the equipment is required to minimize welding seams, which reduces a lot of in-service inspection workload. It also has the advantages of compact structure, good safety, and large power generation, but it also has disadvantages such as difficulty in manufacturing. Its main pipe hot section elbow is changed from the orig...

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Problems solved by technology

However, due to the influence of metal flow during the pressing process and the action of internal force during the deformation of the elbow, the inner hole and outer circumference of the processed nozzle will be greatly deformed after pressing, so the pipe has to be processed again after the pressing is completed. The inner hole and outer circumference of the nozzle are machined, which not only increases the amount of machining, but also because the shape of the deformed nozzle is non-circular, it is easy to cause large shape and position tolerances, which increases the difficulty of machining

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