CN107976486B

CN107976486B - Split pin probe assembly of nuclear power station control rod guide cylinder

Info

Publication number: CN107976486B
Application number: CN201711048963.9A
Authority: CN
Inventors: 马官兵; 林舒啸; 马超; 陈怀东; 王韦强; 林戈; 汤建帮; 朱传雨; 汪双印; 许俊龙; 王佳旭; 曾晨明; 吴健荣
Original assignee: China General Nuclear Power Corp; CGN Power Co Ltd; Suzhou Nuclear Power Research Institute Co Ltd; CGNPC Inspection Technology Co Ltd
Current assignee: China General Nuclear Power Corp; CGN Power Co Ltd; Suzhou Nuclear Power Research Institute Co Ltd; CGNPC Inspection Technology Co Ltd
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2020-07-07
Anticipated expiration: 2037-10-31
Also published as: CN107976486A

Abstract

The invention discloses a split pin probe assembly of a control rod guide cylinder of a nuclear power station, which comprises a probe wafer, a wafer fixing frame for fixing the probe wafer, a bottom plate and a first buffer assembly connected between the bottom plate and the wafer fixing frame, wherein a second buffer assembly is also arranged between the first buffer assembly and the wafer fixing frame and comprises a middle plate connected with the first buffer assembly, a cylinder body sleeved on the middle plate and an elastic rubber ring fixed in the cylinder body, the wafer fixing frame is fixedly inserted in the elastic rubber ring and has a gap with the middle plate, the height of the probe wafer and the wafer fixing frame higher than the second buffer assembly is larger than the distance from the deepest part of a split pin groove to the lower end face of a grid plate, and the distance is a compression distance. The invention can self-adapt to positioning error and mounting error, and the contact pressure of the ultrasonic probe and the opening pin is constant, thereby being beneficial to the repeatability of ultrasonic inspection.

Description

Split pin probe assembly of nuclear power station control rod guide cylinder

Technical Field

The invention relates to the field of nuclear power detection, in particular to a split pin probe assembly of a control rod guide cylinder of a nuclear power station.

Background

The split pin of the control rod guide cylinder is positioned in an upper reactor internals of a nuclear power station reactor, and the split pin has the functions of providing positioning and transverse supporting for the control rod guide cylinder and is an important influence factor for controlling the falling of the control rod according to requirements during power regulation and emergency shutdown of a nuclear power unit. The split pin failure phenomenon appears many times in foreign nuclear power station, and its back fruit is embodied in two aspects, and one is control rod guide cylinder dislocation, and then influences control rod whereabouts time, and its second is cracked split pin part gets into the nuclear power station return circuit mesocycle as the foreign matter, can damage other important equipment, influences nuclear power plant's integrality. Therefore, in-service inspection of the split pin of the control rod guide cylinder is necessary to monitor the quality state of the split pin in the operation process and improve the reliability, safety and integrity of the nuclear power station.

In-service inspection is generally performed in the process of overhaul of a nuclear power generating unit. During overhaul, the whole upper in-pile component assembly is stored in the component water pool. In order to carry out ultrasonic inspection on the key area of the cotter pin, a flat probe is required to be inserted into a cotter pin groove, the width of the groove in the mounting state is 2.696 mm-2.896 mm, the width of a probe assembly is about 2.4mm due to the size limitation of a probe wafer, and the underwater positioning precision requirement is high. And the end part of the cotter pin is recessed 37.75mm from the bottom surface of the upper grid plate, which brings great difficulty to the observation and positioning of the end surface of the cotter pin. In addition, after the nuclear power unit operates for more than 20 years, factors such as deformation of parts, assembly tolerance and the like can cause the cotter pin to deflect to a certain degree, so that the probe assembly needs to have certain flexibility and can adapt to the situation; in addition, the contact pressure of the ultrasonic probe and the opening pin is constant, which is beneficial to the repeatability of ultrasonic examination, and a pressure detection and adjustment mechanism is often required to provide the constant pressure, so that the structure is difficult to arrange on a probe assembly with a small size.

Disclosure of Invention

The invention aims to provide a split pin probe assembly of a control rod guide cylinder of a nuclear power station, which can be self-adaptive and can provide constant contact pressure so as to ensure the detection repeatability.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides a nuclear power station control rod guide cylinder split pin probe subassembly, its includes probe wafer, be used for fixing the wafer mount, the bottom plate of probe wafer and connect in the bottom plate with first buffer assembly between the wafer mount, first buffer assembly with still be equipped with second buffer assembly between the wafer mount, second buffer assembly include with the medium plate that first buffer assembly is connected, the cover is located barrel on the medium plate and be fixed in the inside elastic rubber circle of barrel, the wafer mount is fixed insert locate in the elastic rubber circle and with there is the clearance between the medium plate, probe wafer with the wafer mount is higher than the height of second buffer assembly part is greater than the distance of the deepest terminal surface under the last grid plate of split pin recess, and this distance is the compression distance.

Preferably, the probe assembly further comprises a cover plate which is covered on the cylinder body and sleeved on the wafer fixing frame.

Optimized, the terminal surface has downwardly extending's extension post and by extending the annular plate of the radial outside extension of post under the post lower extreme, first buffering subassembly includes a plurality of wearing to locate simultaneously annular plate with guide post, cover in the bottom plate are located every on the guide post and be located annular plate with supporting spring between the bottom plate, the guide post both ends are equipped with the nut that prevents it from droing from annular plate and bottom plate.

Preferably, the lower end of the wafer fixing frame is provided with a clamping plate which extends outwards along the radial direction, the middle of the elastic rubber ring is provided with a through hole, the inner wall of the through hole is provided with a clamping groove matched with the fixing ring, and the clamping plate is clamped in the clamping groove.

Optimally, the compression distance is 1-5 mm.

Furthermore, the clamping plate is in a runway shape and is provided with two parallel straight edges and an arc-shaped edge connected between the two straight edges.

The invention has the beneficial effects that: the invention can self-adapt to positioning errors and in-pile component installation errors, and the contact pressure of the probe wafer and the opening pin is constant, thereby being beneficial to the repeatability of ultrasonic inspection.

Drawings

FIG. 1: a stereoscopic view of the probe assembly;

FIG. 2: a cross-sectional view of the probe assembly;

FIG. 3: a cross-sectional view of the probe assembly;

FIG. 4: after the probe assembly is attached to the cotter pin groove, the distance between the probe assembly cover plate and the bottom surface of the upper grid plate is 3 mm.

Detailed Description

The invention is described in detail below with reference to embodiments shown in the drawings to which:

as shown in fig. 1, 2 and 3, the split pin probe assembly for the control rod guide cylinder of the nuclear power plant comprises a probe wafer 71, a wafer holder 72 for holding the probe wafer 71, a bottom plate 78, a first buffer assembly connected between the bottom plate 78 and the wafer holder 72, and a second buffer assembly arranged between the first buffer assembly and the wafer holder 72.

The second buffer assembly comprises a middle plate 75 connected with the first buffer assembly, a cylinder 74 sleeved on the middle plate 75, an elastic rubber ring 79 fixed inside the cylinder 74, and a cover plate 73 covering the cylinder 74 and sleeved on the wafer fixing frame 72, the wafer fixing frame 72 is fixedly inserted in the elastic rubber ring 79, a gap is formed between the wafer fixing frame 72 and the middle plate 75, the height of the probe wafer 71 and the wafer fixing frame 72, which is higher than the second buffer assembly, is greater than the distance from the deepest part of the groove of the split pin 721 to the lower end surface of the upper grid plate 722, the distance is a compression distance, and the compression distance is 1-5 mm. The lower end of the wafer fixing frame 72 is provided with a clamping plate 716 extending outwards along the radial direction, the middle part of the elastic rubber ring 79 is provided with a through hole, the inner wall of the through hole is provided with a clamping groove matched with the clamping plate 716, and the clamping plate 716 is clamped in the clamping groove. The clamping plate is in a runway shape and is provided with two parallel straight edges and an arc-shaped edge connected between the two straight edges. When the probe wafer 71 needs to be rotated adaptively, the elastic rubber ring 79 is deformed with the rotation of the wafer holder 72 and is reset after the detection is completed.

Middle plate 75 lower extreme mask has downwardly extending's extension post 714 and by extending post 714 lower extreme along the radial outside annular plate 715 that extends post 714, first buffer unit includes a plurality of wearing to locate simultaneously annular plate 715 with guide post 76, the cover in the bottom plate 78 locate every on the guide post 76 and be located annular plate 715 with support spring 77 between the bottom plate 78, guide post 76 both ends are equipped with the nut 717 that prevents it from droing from annular plate 715 and bottom plate 78.

As shown in fig. 4, when the top end of the probe assembly contacts the end surface of the cotter 721, if there is a certain positioning deviation or installation error, the probe assembly can automatically adjust the posture by the deformation of the elastic rubber ring 79 and the supporting spring 77; after the top end of the probe assembly contacts the top end of the groove of the cotter pin 721, a vertical lifting mechanism (such as an air cylinder can be realized, the focus of the invention is not repeated here) for driving the probe to move up and down continues to rise until the cover plate 73 contacts the upper grid plate 722, and the supporting spring 77 and the elastic rubber ring 79 start to compress. At this time, the contact pressure of the probe assembly and the opening pin 721 is the elastic force of the support spring 77 and the elastic rubber ring 79 which generate 1-5 mm deformation in total, and the elastic force is kept unchanged, in this embodiment, the elastic coefficient of the rubber is 10N/mm, the rubber content and the hardness are adjusted, the pressure applied to the probe is optimally 30N, and therefore, the deformation is optimally 3 mm. The probe assembly has certain flexibility, self-adaptive positioning error and installation error, and can realize that the contact pressure of the ultrasonic probe and the cotter pin 721 is constant in a required range without additional equipment for detecting pressure, thereby being beneficial to the repeatability of ultrasonic inspection.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a nuclear power station control rod guide cylinder split pin probe subassembly, its includes probe wafer, is used for fixing the wafer mount of probe wafer, bottom plate and connect in the bottom plate with the first buffer subassembly between the wafer mount which characterized in that: the probe comprises a first buffering assembly, a wafer fixing frame and a second buffering assembly, wherein the first buffering assembly is arranged on the wafer fixing frame, the second buffering assembly is arranged between the first buffering assembly and the wafer fixing frame, the second buffering assembly comprises a middle plate connected with the first buffering assembly, a cylinder body sleeved on the middle plate and an elastic rubber ring fixed inside the cylinder body, the wafer fixing frame is fixedly inserted into the elastic rubber ring and a gap exists between the middle plates, the height of the probe wafer and the wafer fixing frame is larger than the distance between the deepest part of a groove of a split pin and the lower end face of an upper grid plate, the distance is a compression distance, and the compression distance is 1-5 mm.

2. The nuclear power plant control rod guide cylinder cotter pin probe assembly as recited in claim 1, wherein: the probe assembly further comprises a cover plate which is covered on the cylinder body and sleeved on the wafer fixing frame.

3. The nuclear power plant control rod guide cylinder cotter pin probe assembly as recited in claim 1, wherein: the terminal surface has downwardly extending's extension post and by the annular plate that extends the radial outside extension of post under the post along extending, first buffering subassembly includes a plurality of wearing to locate simultaneously the annular plate with guide post, cover in the bottom plate are located every on the guide post and be located the annular plate with supporting spring between the bottom plate, the guide post both ends are equipped with the nut that prevents it from droing on annular plate and the bottom plate.

4. The nuclear power plant control rod guide cylinder cotter pin probe assembly as recited in claim 1, wherein: the lower end part of the wafer fixing frame is provided with a clamping plate which extends outwards along the radial direction, the middle part of the elastic rubber ring is provided with a through hole, the inner wall of the through hole is provided with a clamping groove matched with the clamping plate, and the clamping plate is clamped in the clamping groove.

5. The nuclear power plant control rod guide cylinder cotter pin probe assembly as recited in claim 4, wherein: the clamping plate is in a runway shape and is provided with two parallel straight edges and an arc-shaped edge connected between the two straight edges.