KR101324716B1

KR101324716B1 - Radiation resistant LVDT for measuring the elongation

Info

Publication number: KR101324716B1
Application number: KR1020100105901A
Authority: KR
Inventors: 이철용; 박승재; 김봉구; 조만순; 주기남; 손재민; 임인철
Original assignee: 한국원자력연구원
Priority date: 2010-10-28
Filing date: 2010-10-28
Publication date: 2013-11-05
Also published as: KR20120044564A

Abstract

Disclosed is a radiation resistant LVDT for strain measurement. The radiation resistant LVDT for deformation measurement is connected to a measurement object, and the deformation of the core is changed according to the change of the measurement object and the position of the variable core is moved through the core spring in the axial direction in the variable position direction. And a detector configured to generate an electrical output with an insulated cable corresponding to the positional displacement of the core in the assembly and the deformation detection assembly.

Description

Radiation resistant LVDT for measuring the elongation

The present invention relates to a linear variable differential transformer (LVDT), and more particularly, to perform irradiation tests in high temperature, high pressure, and high radiation environments to characterize nuclear fuel or material specimens in research reactors. The LVDT used for the purpose should have the characteristics of radiation resistance as well as the conditions of high temperature and high pressure.

Accordingly, the present invention relates to a radiation resistant LVDT for strain measurement used in displacement measurements in nuclear reactor environments.

The present invention is an LVDT widely used in the metrology field by generating electrical output in proportion to the displacement of the core moving independently of external changes.

Commonly used LVDTs are metallic, but cannot be used in reactor conditions, which are extreme environments of high temperature, high pressure and high radiation.

LVDTs, which are used in some high-temperature and radiation-resistant environments, are sold at high prices. However, due to their complex structure and limited size, they are difficult to use for reactor purposes.

Therefore, there is a need for an LVDT that can be easily utilized for use purposes by simplifying and miniaturizing the function for use in a nuclear reactor.

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to solve and compensate for the conventional drawbacks and to simplify and miniaturize the structure to be suitable for use in high temperature, high pressure and high radiation environment.

In addition, the LVDT bottom connection to the specimen was simplified as much as possible to facilitate assembly and welding.

All the components used were selected to be sufficiently resistant to high temperature and high radiation. Especially, LVDT bobbin was used to improve the insulation properties of the coil by using high purity alumina and high purity alumina tube inside the outer cylinder.

In addition, each part was placed to facilitate precision welding to seal the LVDT from external leakage.

Radiation-resistant LVDT for deformation measurement for solving the above problem is connected to the measurement object, the core position is variable according to the change of the measurement object and the position of the variable core through the core spring in the axial direction of the variable position direction And a detection unit configured to move the and a detection unit configured to generate an electrical output with an insulated cable corresponding to the positional displacement of the core in the deformation detection assembly.

The deformation detection assembly includes a core whose position is changed to correspond to a change of the measurement object, a core support for supporting the core whose position is changed, and a core spring surrounding the outside of the core.

The detector includes: an LVDT bar connected to a core support in the deformation detecting assembly; an LVDT outer tube assembled and welded to the LVDT bar; an LVDT shield surrounding the LVDT bar; a lower insulation tube surrounding the LVDT shield; And an insulated inner tube, three LVDT bobbins assembled into the LVDT bar, and an upper end cap fitted into the LVDT outer cylinder.

The detection unit may further include a signal connection tube having an insulation cable connected therein to be electrically connected to the upper end cap.

Each of the three LVDT bobbins is made of an insulating high purity alumina material.

Each of the three LVDT bobbins on which the primary coil and the binary coil are wound may be connected in a line along the axial direction.

Each of the three LVDT bobbins is wound with a coil coated with a ceramic that can withstand high temperatures.

The LVDT shielding agent blocks noise from outside of the three LVDT bobbins.

The bottom insulating inner tube is an insulating alumina tube for heat and radiation shielding.

The bottom insulating tube is characterized in that the insulating alumina tube for heat and radiation shielding.

According to the present invention, the deformation detection assembly of the radiation resistant LVDT for deformation measurement can move the deformation change of the specimen in the axial direction very simply, and the differential transformer assembly blocks the noise from the external radiation environment to keep the electrical signal constant. It can be very useful for measuring strain during irradiation test of nuclear fuel or material specimen in the environment of nuclear reactor.

In addition, the LVDT bobbin and the inner tube can be made of high purity alumina material to improve the insulation properties.

1 is an exemplary view showing a radiation resistant LVDT for deformation measurement according to an embodiment of the present invention.
FIG. 2 is an exemplary view illustrating a deformation detection assembly shown in FIG. 1.
3 is an exemplary view showing a differential transformer assembly shown in FIG. 1.
4 is an exemplary diagram listing the components of the radiation resistant LVDT for strain measurement shown in FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. In addition, the terms "~", "~" described in the specification means a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention.

1 is an exemplary view showing a radiation resistant LVDT for deformation measurement according to an embodiment of the present invention, Figure 2 is an exemplary view showing a deformation detection assembly shown in Figure 1, Figure 3 is a differential transformer assembly shown in Figure 1 4 is an exemplary view listing the components of the radiation resistant LVDT for strain measurement shown in FIG. 1.

As shown in FIGS. 1, 2 and 4, the radiation resistant LVDT 100 for deformation measurement of the present invention includes a deformation detection assembly 200 and a detection unit 300.

The deformation detecting assembly unit 200 is connected to a measurement object, and the core position is changed according to the change of the measurement object and serves to move the position of the variable core through a core spring in an axial direction in the variable position direction. Do this.

More specifically, the deformation detection assembly 200 includes a core support 10, a core 30, and a core spring 20.

The core 30 may be formed of an elastic material whose position may be changed to correspond to the change of the measurement object.

The core support 10 serves to support the position of the core 30 to be changed, and is formed to allow one side to be mechanically connected to the core.

The core spring 20 is formed to surround the outside of the core support 10 and the core 30, and serves to move the position displacement of the core 30 to repeat the expansion and contraction in the axial direction. To perform.

The detector 300 may be configured to generate an electrical output corresponding to a positional displacement of the core 30 in the deformation detection assembly 200 by using an insulation cable.

More specifically, the detector 200 includes an LVDT bar 40, an LVDT outer cylinder 70, an LVDT shield 60, a lower insulation tube 50, an upper insulation tube 90, and three LVDT bobbins 80. And an upper end cap 110.

One end of the LVDT bar 40 may be mechanically connected to the core 30 in the deformation detection assembly 200, and the other end may be mechanically connected to the electromyoelectric bobbin among the three LVDT bobbins.

The LVDT outer cylinder 70 may be assembled and welded to surround the LVDT bar 40.

The LVDT shield 60 is mechanically connected to enclose the LVDT bar 40.

The bottom insulating tube 50 is connected to mechanically wrap the LVDT shield 60.

The upper insulating tube 90 may be positioned above the lower insulating tube 50 to be mechanically wrapped.

Each of the three LVDT bobbins 80 may be assembled and arranged in a line to be mechanically connected to the LVDT bar 40.

The upper end cap 110 is mechanically connected to the insulated inner tube 90 to fit into the LVDT outer cylinder 70.

In addition, the detector 300 may further include a signal connection tube 120 having an insulating cable connected therein to be electrically connected to the upper end cap 110.

Each of the three LVDT bobbins 80 may be made of an insulating high purity alumina material.

In addition, each of the three LVDT bobbins 80 may be configured to be connected in a line along an axial direction (eg, the position direction of the core).

Each of the three LVDT bobbins 80 may be configured such that a coil coated with a ceramic that can withstand high temperatures is wound.

The LVDT shield 60 may be configured to block noise from the outside to the three LVDT bobbins 80.

The lower insulating tube 50 may be formed of an insulating alumina tube for shielding heat and radiation.

The upper insulating tube 90 may be formed of a material of an insulating alumina tube for shielding heat and radiation.

1 and 4, the deformation detection assembly 200 is connected to the measurement object, the position of the core 30 is changed in accordance with the change of the measurement object in the axial direction of the variable position direction The core spring 20 serves to move the position of the variable core.

The detection unit 300 has the LVDT bar 40, one end of which is mechanically connected to the core 40 in the deformation measuring assembly, and the other end of which is mechanically connected to the three LVDT bobbins 80.

The LVDT outer cylinder 70 is then provided to surround the LVDT bar 40.

The outer surface of the LVDT bar 40 is provided to be mechanically connected by using the LVDT outer cylinder 70.

The three LVDT bobbins 80 are assembled to be mechanically connected to the LVDT bar 40 and can be arranged in a line.

The upper end cap 110 is mechanically connected to the upper insulating tube 90 so as to fit into the LVDT outer cylinder 70.

In addition, the detector 300 further includes a signal connection tube 120 having an insulation cable connected therein to be electrically connected to the upper end cap 110.

Each of the three LVDT bobbins 80 is configured such that a coil coated with a ceramic which can withstand high temperatures is wound, and the LVDT shielding agent 60 blocks noise from the outside of the three LVDT bobbins 80. The lower insulating tube 50 may be formed of a material of an insulating alumina tube for shielding heat and radiation, and the upper insulating tube 90 may be formed of a material of an insulating alumina tube for shielding heat and radiation. .

Finally, after injecting the helium gas from the outside so as to fill the inside of the strain measuring LVDT of the present invention, after the pin welding, the helium leak test is performed to check the sealing state. This may be to check the health of the LVDT.

Therefore, the present invention can simply move the deformation change inside the nuclear fuel rod in the axial direction as it is, and the detection unit 300 generates an electrical signal by blocking the noise from the external radiation environment and generates the electrical signal on the basis of the electrical signal. The change in deformation can be measured.

In addition, the overall structure of the radiation resistant LVDT 100 for deformation measurement according to the present invention can be improved in size by miniaturization and minimizing the number of parts for use in reactor conditions.

In addition, the use of high-purity alumina materials for the LVDT bobbin and the inner tube can improve the insulation properties.

In addition, each part of the assembled LVDT is sealed by precision welding so that it is completely isolated from the outside. The LVDT operation of measuring the differential of the core position may output an electrical signal from the detector in proportion to the displacement of the detector.

The present invention is not limited to the above-described specific preferred embodiments, and any person skilled in the art to which the present invention pertains can perform various differentials without departing from the gist of the present invention as claimed in the claims. Of course, such changes will fall within the scope of the claims.

10: core support 20: core spring
30: core 40: LVDT bar
50: lower insulation inner tube 60: LVDT shield
70: LVDT outer cylinder 80: 3 LVDT bobbins
90: top insulation inner tube 110: top end cap
120: signal connection tube

Claims

A deformation detecting assembly unit connected to a measurement object and moving a position of the variable core through a core spring in an axial direction in which the core position is changed according to the change of the measurement object and the variable position direction; And
It includes a detector for outputting the electrical output generated through the insulated cable corresponding to the positional displacement of the core in the deformation detection assembly,
The deformation detection assembly,
A core 30 whose position is changed to correspond to the change of the measurement object;
A core support (10) for supporting the core in which the position is changed; And
It includes a core spring 20 surrounding the outside of the core,
Wherein:
An LVDT bar connected with a core support in the deformation detection assembly;
An LVDT outer cylinder which is assembled and welded to the LVDT bar;
An LVDT shield surrounding the LVDT bar;
A bottom insulation tube surrounding the LVDT shield;
An upper insulating inner tube surrounding the lower insulating tube;
Three LVDT bobbins connected to the LVDT bar; And
A radiation resistant LVDT for strain measurement comprising an upper end cap fitted to the LVDT outer cylinder.

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The method of claim 1,
Wherein:
The radiation resistant LVDT for strain measurement further comprising a signal connection tube having an insulated cable connected therein to be electrically connected to the upper end cap.

The method of claim 1,
Each of the three LVDT bobbins,
A radiation resistant LVDT for strain measurement, comprising an insulating high purity alumina material.

The method of claim 1,
Each of the three LVDT bobbins,
A radiation resistant LVDT for strain measurement, connected in series along the axial direction.

The method of claim 1,
Each of the three LVDT bobbins,
A radiation resistant LVDT for strain measurement, characterized by a coil coated with a ceramic that can withstand high temperatures.

The method of claim 1,
The LVDT shielding agent,
The radiation resistant LVDT for strain measurement, characterized in that to block noise from the outside to the three LVDT bobbins.

The method of claim 1,
The lower insulation inner tube,
A radiation resistant LVDT for strain measurement, characterized by an insulating alumina tube for heat and radiation shielding.

The method of claim 1,
The lower insulation tube,
A radiation resistant LVDT for strain measurement, characterized by an insulating alumina tube for heat and radiation shielding.

A deformation detection assembly unit configured to selectively move a position of the variable core by using a core spring in an axial direction, the core position of which is changed according to a change of a measurement object and the direction of the variable core; And
It includes a detector for outputting the electrical output generated through the insulated cable corresponding to the positional displacement of the core in the deformation detection assembly,
The detector includes: an LVDT bar connected to a core support in the deformation detecting assembly; an LVDT outer tube assembled and welded to the LVDT bar; an LVDT shield surrounding the LVDT bar; a lower insulation tube surrounding the LVDT shield; A radiation resistant LVDT for strain measurement comprising an insulated inner tube, three LVDT bobbins connected to the LVDT bar.

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