Self-adaptive positioning device and method for tube plate cleaning nozzle of steam generator

Abstract

The invention provides a steam generator tube plate cleaning nozzle self-adaptive positioning device which comprises a sealing shell, a visual camera, a light source component, a transparent plate and a rear plate, the visual camera and a light source are installed in the sealing shell, the front end of the sealing shell is sealed through the transparent plate, and the rear end of the sealing shell is sealed through the rear plate. The invention further provides a nozzle self-adaptive positioning method. The method comprises the steps that S1, a heat transfer tube picture is collected through the terminal image collection system; s2, preprocessing the image; s3, detecting the edge of the heat transfer pipe; s4, extracting edge feature points of the heat transfer tube; s5, fitting the edge straight line of the heat transfer tube by adopting a least square method, so that the quadratic sum of the distance from each edge point to the fitted straight line is minimum, and positioning a central point; and S6, determining position deviation, and realizing position compensation through motion control. The self-adaptive positioning device and method can realize self-adaptive positioning of the nozzle, are high in positioning precision, and can be applied to various nuclear power station units.

Description

Technical field [0001] The present invention relates to the field of steam generator overhaul technology, in particular to a steam generator tube plate cleaning nozzle adaptive positioning device and method. Background [0002] During the operation of the nuclear power plant, the outer surface of the heat transfer pipe at the secondary side pipe plate of the steam generator is concentrated and deposited to form surface scaling due to impurities and ions in the secondary circuit, and this surface scaling phenomenon becomes more and more serious over time, which eventually causes the evaporator to be unable to operate normally, so maintaining the excellent cleanliness of the evaporator of the nuclear power plant plays an important role in improving the power generation efficiency of the nuclear power plant. Due to the narrow internal spatial structure of the evaporator and the influence of nuclear radiation, it is impossible to perform manual cleaning tasks, and it is necessary to ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two positioning schemes for the cleaning nozzle of the tube sheet on the secondary side of the evaporator. The first is to install an encoder on the drive motor of the stepping mechanism equipped with the nozzle. Through the feedback value of the encoder, combined with the stepping motor and the reduction box And the transmission ratio of the transmission mechanism such as the worm gear to convert the position of the nozzle. During the flushing process, due to the comprehensive factors such as the cumulative step error and the track installation error, the nozzle is easy to deviate from the position between the tubes. The initial position of the nozzle is calibrated, and there are errors in manual calibration; the second is to use the regularity of the layout of the heat transfer tubes. The cylinder, and the carrier is equipped with movable claws and fixed claws, the fixed claws are loosened, and the movable claws grasp the heat transfer tube. The heat transfer tube is mechanically positioned, so the positioning accuracy is high, but this method needs to arrange movable claws, fixed claws and cylinders, and the nozzle carrier has a large shape, so it can only be used in evaporators with no blocking blocks in the central pipe gallery. It can only be used in the evaporator of the AP1000 unit in China for the time being

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