Method for accurately positioning reactor core of loading and unloading machine

Abstract

The invention belongs to the technical field of nuclear fuel loading and unloading of nuclear power plant reactors, and particularly relates to a method for accurately positioning a reactor core of a loading and unloading machine. Moving the loading and unloading machine and automatically positioning to the middle position of the reactor core; slowly descending the simulation component, and judging whether the component is smoothly in place or not; if the assembly cannot be in place smoothly, the loading and unloading machine is moved until the assembly is in place smoothly, and coordinate values of the large trolley and the small trolley at the moment are recorded; after the assembly is lifted to the safe height, the loading and unloading machine is shifted towards the 0-degree side of the trolley by 2 mm; if the assembly can still be in place smoothly, the assembly continues to be lifted to the safe height, offset operation is repeated towards the 0-degree side of the trolley till the assembly cannot be in place, and the direction coordinate value a of the trolley at the moment is recorded; the loading and unloading machine is moved to the initial in-position coordinate of the assembly, the offset operation is repeated in the 180-degree direction of the trolley till the 180-degree side assembly cannot be in position, and the direction coordinate value b of the trolley at the moment is recorded; the average value of a and b is the positioning coordinate of the reactor core in the trolley direction. Accurate positioning of the reactor core can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel loading and unloading of a nuclear power plant reactor, and in particular relates to a method for accurately positioning a core of a loading and unloading machine. Background Art

[0002] The loader is a special equipment for nuclear fuel assemblies in the reactor core of a pressurized water reactor nuclear power plant. It is mainly used to unload and load nuclear fuel in the core during overhaul. The loader is generally positioned with the upper tube seat of the nuclear fuel assembly through guide pins and connected to the assembly with an openable claw hook. The nuclear fuel assembly is positioned through the guide holes of the lower tube seat and the guide pins of the core bottom plate.

[0003] At present, the method generally used for positioning the fuel loading and unloading equipment and the core of a pressurized water reactor is to use the nuclear fuel simulation assembly to visually align the core. The specific steps are as follows: 1. The loader grabs the simulation assembly and moves it to the center of the core; 2. Lower the simulation assembly until it is close to the height of the guide pins on the core bottom plate; 3. Visually adjust the positioning and centering of the loader through a telescope; 4. Move the loader to four points evenly distributed on the edge of the core for visual centering; 5. Determine the final core positioning coordinates based on the centering situation. This positioning method is more dependent on the skill level of the operator and is limited by visual conditions, so it has certain limitations. Summary of the invention

[0004] The purpose of the present invention is to provide a method for accurately positioning the core of a loader and unloader, and to obtain accurate core positioning by calculation and experiment, so as to improve the efficiency and safety of loading and unloading of nuclear fuel assemblies.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for accurately positioning the core of a loading and unloading machine,

[0007] 1. Move the loader and unloader and automatically position it to the middle of the core;

[0008] 2. Slowly lower the simulated component to determine whether the component is successfully in place;

[0009] 3. If the component cannot be put into place smoothly, move the loading and unloading machine until the component is put into place smoothly, and record the coordinate values ​​of the large and small vehicles at this time;

[0010] 4. After the components are lifted to a safe height, offset the loader 2mm to the 0° side of the trolley;

[0011] 5. If the component can still be put into place smoothly, continue to lift the component to a safe height and repeat the offset operation to the 0° side of the trolley until the component just cannot be put into place, and record the trolley direction coordinate value a at this time;

[0012] 6. Move the loader to the initial positioning coordinate of the component, and repeat the above offset operation in the 180° direction of the trolley until the 180° side component just cannot be positioned, and record the trolley direction coordinate value b at this time;

[0013] 7. The average value of a and b is the core positioning coordinate in the direction of the trolley;

[0014] 8. Move the loader to the initial positioning coordinate of the component, and repeat the above offset operation in the 90° direction of the truck until the 90° side component just cannot be positioned, and record the coordinate value c in the direction of the truck at this time;

[0015] 9. Move the loader to the initial positioning coordinate of the component, repeat the above offset operation in the 270° direction of the truck, until the 270° side component just cannot be positioned, and record the coordinate value d in the direction of the truck at this time;

[0016] 10. The average value of c and d is the core positioning coordinate in the direction of the trolley.

[0017] 2. Determine whether the components are in place smoothly by the positioning height and load of the loader and unloader, combined with visual observation.

[0018] 3. Move the loader and unloader by underwater TV or telescope.

[0019] The beneficial effects achieved by the present invention are:

[0020] The method of the present invention obtains the component placement boundary information through quantitative offset and obtains the core positioning coordinates through calculation. The method of the present invention significantly improves the positioning accuracy of the loading and unloading equipment, which has an important impact on the safety and efficiency of subsequent loading and unloading operations. The method of the present invention can effectively overcome the unfavorable factors such as visual centering error and the influence of core water quality visibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the lower tube seat of the component;

[0022] Figure 2 This is a schematic diagram of the lower core plate;

[0023] Figure 3 It is a flow chart of the present invention;

[0024] In the figure: 1 lower pipe seat; 2 lower core bottom plate; 3 positioning hole; 4 guide pin. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The core positioning of the loader and unloader is the centering accuracy of the lower tube seat 1 and the installation position on the lower core bottom plate 2 when the loader and unloader grabs the fuel assembly. The loader and unloader is positioned by the positioning hole 3 of the lower tube seat of the assembly and the guide pin 4 of the lower core bottom plate. The positioning hole 3 and the guide pin 4 are both processed with conical guide surfaces and have smooth transitions. The positioning holes 3 and the guide pins 4 are arranged diagonally and correspond to each other.

[0027] The core positioning is mainly to achieve accurate centering of the trolley direction (0°-180°) and the truck direction (90°-270°). The specific operation method of centering is as follows:

[0028] 1. Move the loader and unloader and automatically position it to the middle of the core.

[0029] 2. Slowly lower the simulated component, and determine whether the component is successfully positioned by checking the positioning height and load of the loader and unloader, combined with visual observation.

[0030] 3. If the component cannot be smoothly put into place, move the loader and unloader through the underwater TV or telescope until the component is successfully put into place, and record the coordinate values ​​of the large and small vehicles at this time.

[0031] 4. After the assembly is lifted to a safe height, offset the loader 2mm to the 0° side of the trolley.

[0032] 5. If the component can still be put into place smoothly, continue to lift the component to a safe height and repeat the offset operation to the 0° side of the trolley until the component just cannot be put into place, and record the trolley direction coordinate value a at this time.

[0033] 6. Move the loader to the initial positioning coordinate of the component, and repeat the above offset operation in the 180° direction of the trolley until the 180° side component just cannot be put into place, and record the trolley direction coordinate value b at this time.

[0034] 7. The average value of a and b is the core positioning coordinate in the direction of the trolley.

[0035] 8. Move the loader to the initial positioning coordinate of the component, repeat the above offset operation in the 90° direction of the truck, until the 90° side component just cannot be put into place, and record the coordinate value c in the direction of the truck at this time.

[0036] 9. Move the loader to the initial positioning coordinate of the component, repeat the above offset operation in the 270° direction of the truck, until the 270° side component just cannot be put into place, and record the coordinate value d in the direction of the truck at this time.

[0037] 10. The average value of c and d is the core positioning coordinate in the direction of the trolley.

[0038] The present invention can complete the precise positioning of the loader and unloader in the core area through quantitative offset detection and calculation of the directions of the large and small vehicles; the positioning method has higher positioning accuracy than the visual centering method; the positioning method is not affected by factors such as visual inspection and water quality visibility, and can effectively ensure positioning accuracy.

[0039] 1. The loader grabs the simulated component and automatically moves to the core center coordinate; 2. Lower the simulated component until it is close to the height of the core bottom plate guide pin; 3. Slowly lower the component and determine whether the component is in place by load, height and visual inspection; 4. If the component cannot be smoothly positioned, the large and small vehicles can be fine-tuned until the component is smoothly positioned, and the initial coordinate value is recorded; 5. Lift the component to a position higher than the core bottom plate guide pin; 6. The loader is offset 2mm to the 0° side of the small vehicle and lowered to position. If it can be smoothly positioned, it continues to be offset to the 0° side until the component cannot be positioned. Record the coordinate value of the small vehicle at this time; 7. Move the loader to the initial coordinate value, and deflect the small vehicle 2mm to the 90° side and lower it to position. If it can be smoothly positioned, it continues to be offset to the 90° side until the component cannot be positioned. Record the coordinate value of the small vehicle at this time; 8. Calculate and obtain the core positioning coordinates in the direction of the small vehicle; 9. The core coordinate positioning operation in the direction of the large vehicle is basically the same as the positioning method of the small vehicle.

Claims

1. A method for accurate positioning of a core of a loading and unloading machine, characterized in that:

1. Move the loader and unloader and automatically position it to the middle of the core; 2. Slowly lower the simulated component to determine whether the component is successfully in place; 3. If the component cannot be put into place smoothly, move the loading and unloading machine until the component is put into place smoothly, and record the coordinate values ​​of the large and small vehicles at this time; 4. After the components are lifted to a safe height, offset the loader 2mm to the 0° side of the trolley; 5. If the component can still be put into place smoothly, continue to lift the component to a safe height and repeat the offset operation to the 0° side of the trolley until the component just cannot be put into place, and record the trolley direction coordinate value a at this time; 6. Move the loader to the initial positioning coordinate of the component, and repeat the above offset operation in the 180° direction of the trolley until the 180° side component just cannot be positioned, and record the trolley direction coordinate value b at this time; 7. The average value of a and b is the core positioning coordinate in the direction of the trolley; 8. Move the loader to the initial positioning coordinate of the component, and repeat the above offset operation in the 90° direction of the truck until the 90° side component just cannot be positioned, and record the coordinate value c in the direction of the truck at this time; 9. Move the loader to the initial positioning coordinate of the component, repeat the above offset operation in the 270° direction of the truck, until the 270° side component just cannot be positioned, and record the coordinate value d in the direction of the truck at this time; 10. The average value of c and d is the core positioning coordinate in the direction of the trolley.

2. The method for accurate positioning of the core of a loader and unloader according to claim 1, characterized in that:

2. Determine whether the components are in place smoothly by the positioning height and load of the loader and unloader, combined with visual observation.

3. The method for accurate positioning of the core of a loader and unloader according to claim 1, characterized in that:

3. Move the loader and unloader by underwater TV or telescope.

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