KR20010107216A - Pendulum Type Impact Tester with Manipulator and Analog Type Angular Transducer - Google Patents

Abstract

The present invention relates to an apparatus for impact testing under normal and high temperature environments for a support grid having a function of supporting fuel rods among fuel assembly components of a reactor for light water reactors. Also, the front and rear movement adjuster of the impact hammer was attached to allow the impact at the lowest point. Also, when the distance between the support grids of the fuel assembly was changed, the length of the impact hammer pendulum was needed to make it possible. In addition, a separate furnace was attached to allow the impact test to be carried out at room temperature and high temperature, and an impact hammer fixing device using an electromagnet was attached so that the angle of the initial impact hammer could be maintained even at any initial angle. It was. In addition, an analog angle conversion system that tracks the angle of the hammer in the time domain during the impact test was attached to collect the hammer angle during the impact test as an analog signal. The pendulum-type impact hammer was designed to easily change the mass of the impact hammer in consideration of the fact that the mass of the hammer should be changed according to the number of cells of the support lattice specimen.

Description

Pendulum Type Impact Tester with Manipulator and Analog Type Angular Transducer

The present invention relates to an apparatus for impact testing under normal temperature and high temperature environment with respect to a support grid having a function of supporting a fuel rod among fuel assembly components of a light reactor, in particular, a support grid specimen having an arbitrary number of cells. The impact at the lowest point is possible, and the pendulum length of the impact hammer can be adjusted when the distance between the support grids of the fuel assembly is changed, and the angle of the initial impact hammer can be maintained at any initial angle. Accordingly, the present invention relates to a pendulum-type impact tester that can track an angle of a hammer and collect it as an analog signal, and can adjust an arbitrary impact angle and an impact point to easily change the mass of an impact hammer.

In general, the support grid is one of the components of the nuclear reactor fuel assembly and has a function of supporting the springs and dimples in each lattice of the support grid so that the fuel rods are arranged at a predetermined position. If the spring force in the spring and dimple is too small, it may be impossible to arrange the fuel rod in a fixed position, and if it is too large, the fuel rod may lose its supporting integrity. If it is too large, the surface of the fuel rod may be excessive due to excessive frictional resistance when the fuel rod is inserted into the support grid. Scratches, such as scratches, may occur and the rods may not be adequately accommodated for longitudinal growth of the fuel rods by neutron irradiation during reactor operation, causing the fuel rods to bend, i.e., causing bending of the fuel rods.

When the fuel rods are bent, the fuel rods are brought into close proximity or contact with adjacent fuel rods, narrowing or blocking the coolant flow path between the fuel rods, which leads to a local fuel rod temperature increase because the heat generated from the fuel is not effectively transferred to the coolant. It is also the main cause of reducing the output of nuclear fuel by increasing the possibility of nuclear boiling deviation.

Today, the development of nuclear fuel is being pushed towards achieving high combustion and flawlessness. In order to develop high-combustion fuels, it is necessary to promote heat transfer from the fuel rods to the cooling water, that is, to improve the thermal performance of the nuclear fuel. That's how. To this end, the shape change of the support grid itself is mainly performed, for example, the attachment of the mixing blade and the design change thereof or the efficient configuration of the flow channel.

The conventional nuclear fuel assembly 1 shown in FIGS. 1 and 2 forms an overall skeleton between the upper fixture 2 and the lower fixture 3 with a plurality of guide tubes 4, and a fuel rod 9 The support grids 7 and 8 for supporting them are formed at a constant interval in the longitudinal direction of the guide tube to form the nuclear fuel assembly 1 by welding with the guide tube. The support grids (7, 8) for constructing the fuel assembly (1) are thin plated to withstand the impact load from the side direction under the support of the fuel rod (9) and accident conditions such as earthquake or loss of coolant accident (LOCA). A lattice structure formed by forming a lattice structure and welding the intersection thereof.

There are fuel rod unit grids supporting fuel rods and guide tube unit grids into which guide tubes are inserted, and fuel rod unit grids provide point contact, line contact or surface contact with fuel rods at six support points of two springs and four dimples. It forms and supports the fuel rod by the friction force between these support parts and a fuel rod.

Crash tests on the side of support grids used as fuel assembly components for light-water reactors have been carried out by pendulum and free fall. In these test apparatuses, it is possible to obtain the impact force and impact acceleration that the lattice specimens receive depending on the free fall height and any initial impact hammer angle. Dynamic impact strength assessment of structures usually involves attaching strain gauges to specimens and attaching force transducers to impact hammers. The method of attaching strain gauge is mainly used in preliminary test to check the linearity of impact input and impact force, but it is difficult to attach strain gauge depending on the shape of the specimen and it is difficult to confirm the reliability of the collected signal. It is difficult to apply to impact test of support grid. On the other hand, the method of attaching the force transducer is mainly used to obtain the ultimate strength of the specimen, and there is an advantage that it is easy to apply compared to the method of attaching the strain gauge.

However, the currently applied test method has a problem in that the repulsive coefficient of the lattice structure cannot be obtained because the falling signal cannot be collected after impacting the support grid in the case of free-falling type. In the case of having various types of cells, it is difficult to follow the impact hammer mass, the length of the pendulum, the initial angle of the impact hammer, and the angle of the impact hammer after impacting the specimen entirely in the time domain. .

The present invention has been made to solve the above problems of the prior art, to evaluate the dynamic impact characteristics of the support grid, which is one of the components of the fuel assembly for the light-reactor, impact hammer according to the change of the number of support grid cells The mass of can be varied, and the change of distance between support lattice in the fuel assembly can accommodate this length to obtain the support lattice repulsion coefficient, and the change of the length of the impact hammer pendulum and the angle of the impact hammer during the impact test of the support lattice Can be collected in real time to obtain data on the initial angle of impact hammer and the angle of rebound of hammer after impact, as well as to adjust the arbitrary impact angle and impact point to obtain the impact characteristics of support grid under high temperature environment The aim is to provide this possible pendulum impact tester.

1 is a schematic perspective view of a partially cut fuel assembly;

2 is a schematic perspective view of a support grid for the construction of a fuel assembly;

3 is a schematic diagram of a pendulum impact tester capable of adjusting any impact angle and impact point according to the present invention;

4 is a detailed view of the impact hammer capable of removing noise during the impact test according to the present invention;

FIG. 5 is a detailed view of the pendulum and hammer connection to ensure that the hammer is horizontal even in angular motion of the pendulum when the impact hammer is impacted at any initial angle, FIG.

Figure 6 is a schematic view of the hammer pendulum fixture to allow adjustment of the loading point and the pendulum length of the impact hammer according to the present invention, Figure 7 is an electromagnet hammer capable of impacting the specimen at an initial arbitrary angle according to the present invention Schematic diagram of the fixing device,

8 is a schematic diagram of a furnace that enables an impact test in a room temperature and a high temperature environment according to the present invention,

Figure 9 is a schematic diagram of a specimen holding device that can correct this amount of deformation when deformation of the specimen due to impact load inside the furnace according to the present invention.

<Explanation of symbols on main parts of the drawings>

101: impact tester 102: impact hammer

103: support structure 104: pillar

105, 106: pendulum 107: regulator

108: Angular transformation system 109: No

111: fan 112: electromagnet

113: handle 114: collision cap

115: accelerometer 116: force transducer

117 crash tip 118 fixture

119 Psalm 120 Plate

121: spring

A first aspect of the present invention is a support structure fixed at a certain position, a test piece fixed body for fixing the support grid specimen to be fixed to a predetermined position of the support structure to be a collision test, and fixed to the support structure and impact A pillar supporting the hammer, pendulum means for installing the impact hammer on the pillar so that the impact hammer can collide horizontally with the support grid specimen at the lowest kinetic energy, and the height and the specimen of the pendulum means; Adjuster installed on the pillar to adjust the distance of the hammer, the hammer fixing means for fixing the impact hammer to maintain the potential energy at a certain height, and installed in front of the impact hammer when colliding with the support grid specimen Characterized in that it consists of a measuring means for measuring the impact force.

In addition, the present invention is the specimen fixture is fixed to the support structure and fixed to the specimen in one direction, a plate installed to fix the specimen from the opposite side of the fixture, and the plate is the support grid body specimen It characterized in that it consists of elastic means for providing an elastic force to always contact.

In addition, the present invention is the pendulum means is composed of a plurality of pendulum is installed so that the upper end is rotatably installed in the regulator and the lower end is rotatable to the hammer, the pendulum is the impact hammer is horizontal to the support grid body specimen It is configured to collide in a state, and an analog angular conversion system is installed at a connection point of one of the plurality of pendulums to measure the angle of the pendulum over time and at the same time obtain the repulsive coefficient of the support grid. .

In addition, the present invention is the accelerometer is installed in front of the impact hammer, the cap is installed to isolate the accelerometer to isolate the noise, the impact tip is provided in front of the cap collide with the specimen, It is installed between the impact tip and the cap is characterized in that it consists of a force transducer to receive the impact force to collect the impact force to measure the impact force.

In another aspect, the present invention is characterized in that the hammer fixing means is composed of a fixing means installed so as to be transported in a straight line on the support structure, and a handle for inputting a driving force for transferring the electromagnet.

In addition, the present invention is characterized in that the fixing means is an electromagnet.

In addition, a second feature of the present invention is a pendulum-type impact tester for measuring the impact amount by installing the impact hammer on the pendulum and freely dropping at a predetermined angle to impinge on the specimen of the support grid body, the outside of the support grid body specimen The furnace is characterized in that it is installed to adjust the test temperature. In addition, the present invention is characterized in that a fan is installed inside the furnace for the uniformity of temperature.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a schematic view of a pendulum-type impact tester 101 capable of adjusting any impact angle and impact point according to the present invention. The mass of the impact hammer 102 varies according to the number of cells of the lattice, The length of the pendulums 105 and 106 may vary depending on the geometric data, so that the impact tester 101 can evaluate the strength of the lattice structure due to the impact load on the side of the lattice structure designed to accommodate such conditions. It is shown.

4 is a schematic view of the impact hammer 102 according to the present invention, the accelerometer 115 for measuring the impact acceleration during the impact test is attached to the rigid body 102 can isolate the noise (isolation), In the column 104 for supporting the impact hammer at the fixed point, only the movement in a single direction is possible, and the movement in the other direction is constrained. In addition, the force transducer 116 for measuring the impact force is fixed between the impact cap 114 and the impact tip (117, tip) to accurately collect the impact force signal at the time of impact.

FIG. 5 shows that the pendulum 105 and 106 are rotated at an initial random angle during the pendulum impact test of the grating structure according to the present invention, and the impact hammer 102 is released by a signal and is impacted. Was added. Therefore, even when the impact hammer 102 maintains an arbitrary angle, the angle of the impact hammer 102 should be kept parallel to the main body of the tester. Therefore, the impact hammer 102 is rotated at an arbitrary angle by inserting a bearing 114 into the body to engage the pendulum 105 and 106 for connecting the impact hammer 102 to the pillar 104. Even if the body of the impact hammer 102 was to be always kept horizontal.

6 is a column 114 for fixing the impact hammer 102 according to the present invention to the tester body. The pendulums 105 and 106 are moved in the front and rear direction of the impact hammer 102 according to the number of cells of the lattice structure. It should be possible that the impact at the point of maximal kinetic energy should be possible at all times, and the pendulum axial movement was made easy to change the length of the pendulums 105 and 106 according to the distance between the fuel assembly support grids. In addition, by attaching an analog angle conversion system 108 to one of the four supports for fixing the impact hammer 102, the angle of the impact hammer 102 in the time domain during the test as well as the initial angle of the impact hammer 102 We can collect and determine the restitution factor, one of the dynamic impact characteristics of the lattice structure.

7 is an electromagnet 112 as a fixing device for fixing the impact hammer 102 according to the present invention. The initial angle of the impact hammer 102 is maintained by magnetic force, and the impact hammer 102 according to a signal. To be released. In addition, the electromagnet 112 can move in the front and rear direction by using the handle 113 in accordance with the angle of the initial impact hammer 102, so that the hammer having an arbitrary angle can be fixed at all times.

8 shows a schematic of a furnace 109 for carrying out an impact test of a grating structure according to the invention under ambient and room temperature conditions.

9 shows that the support grid specimen 119 is deformed as the impact load is applied during the impact test of the support grid specimen 119 according to the present invention, and the support grid specimen 119 and the impact load are deformed by the deformation. A gap with a plate 120 may be generated to uniformly distribute the grid structure. To prevent this, a coil spring 121 is attached to the front surface of the plate 120 so that a load is applied to the grid to deform the grid. Even if arising so that the specimen and the plate 120 can always be in contact with.

As described above with reference to the drawings, the present invention is a support structure 103 for supporting a variety of devices, a column 104 fixed to the upper portion of the support structure 103, the constant of the column 104 A plurality of pendulums 105 and 106 installed to be moved up, down, left and right at a height, and an adjuster connecting the pillars 104 and the pendulums 105 and 106 to adjust the positions of the pendulums 105 and 106 ( 107, an analog angular conversion system 108 installed at the upper end of the pendulum 105 to measure the rotation of the pendulum 105, and an impact hammer 102 provided at the lower end of the pendulum 105, 106. It consists of.

In addition, the accelerometer 115 is installed on the front of the impact hammer 102 to measure the impact acceleration, the collision cap 114 is installed to surround the accelerometer 115 to isolate the noise, and the collision It consists of a force transducer 116 fixed between the cap 114 and the impact tip 117 to accurately collect the impact force signal at the time of impact.

In addition, a furnace 109 installed to test the support grid specimen 119 at room temperature or high temperature, a fan 111 connected to a motor installed on the top of the furnace 109, and an impact force on the specimen 119. The fixture 118 for fixing the specimen 119 so that it is properly delivered, the plate 120 is installed in contact with the specimen 119 on the opposite side of the fixture 118, and the plate 120 is the specimen It is composed of a spring 121 for providing an elastic force to the plate 120 to contact the (119).

In addition, the impact hammer 102 is configured to maintain the initial angle of the fixed state at a constant height after the impact test and release the electromagnet 112, and the handle 113 installed to adjust the position of the electromagnet 112. do. As the handle 113 rotates, the electromagnet 112 is linearly moved.

Here, the pendulums 105 and 106 and the impact hammer 102 are connected by bearings 105a and 106a, and the impact hammer 102 released from the electromagnet 112 is the maximum kinetic energy as shown in FIG. 5. It is connected to collide with the specimen 119 horizontally at the lowest point to exert.

Looking at the operation of the pendulum-type impact tester capable of adjusting any impact angle and impact point according to the present invention configured as described above are as follows.

First, the specimen 119 is installed well to be fixed to the fixture 118, and the temperature of the furnace 109 and the fan 111 is determined by determining whether to test at room temperature or at a constant high temperature. The temperature inside the furnace 109 is prepared to reach the desired temperature.

Once the specimen 119 is installed, it is determined by adjusting the position of the impact hammer 102 using the adjuster 107 to suit the test.

Thereafter, the electromagnet 112 is advanced by using the handle 113 to make the impact hammer 102 contact, and the electric power is supplied to the electromagnet 112 so that the impact hammer 102 has the magnetic force of the electromagnet 112. To be fixed by Of course, the handle 113 may be operated manually, but for the convenience of the user, a motor may be installed and connected to the handle 113 to be automated.

In such a state, the handle 113 is rotated in the opposite direction to retract the electromagnet 112. When the user stops the handle 113 at a predetermined position, the impact hammer 102 is positioned at a predetermined height. In this case, the angle of the pendulum 105 is recognized by the angular conversion system 108.

In the state where the test preparation is completed as described above, when the power supplied to the electromagnet 112 is cut off, the impact hammer 102 is released by the magnetic force is released from the electromagnet 102 and accordingly the impact hammer 102 is It begins to fall freely by its weight. The impact hammer 102 is free fall while being released from the electromagnet 112 as described above, the free fall by a plurality of pendulums 105, 106 to maintain a horizontal state, the kinetic energy reaches the maximum At the lowest point it will hit the specimen 119. That is, the collision tip 117 impinges on the specimen 119, the acceleration due to the collision is measured by the force transducer 116 and the accelerometer 115, the noise caused by the collision is accelerometer 115 Is surrounded by the cap 114, it is possible to isolate the noise.

In addition, the impact hammer 102 is configured so that the pendulums 105 and 106 can move only in a single direction, so that the pendulum movement is precisely made to impinge on the specimen at the correct point.

When the impact hammer 102 collides with the specimen 119, the analog angle conversion system 108 attached to one of the fixed points of the pendulums 105 and 106 is not only an initial angle but also a time domain during the test. By collecting the angle of the hammer (102) in the Equation to obtain the restitution factor (restitution factor) which is one of the dynamic impact characteristics of the grid structure.

As such, the pendulum-type impact tester which can adjust any impact angle and impact point according to the present invention is an impact test apparatus for dynamic impact test of a support lattice, which is one of the components of a fuel assembly for a light reactor, It is easy to change the mass of the impact hammer even with the number of cells, and even at the lowest point where the kinetic energy of the hammer is maximized through the manipulator of the impact hammer even if the distance between the support grids is changed, the angle of the hammer By collecting in real time, it provides the effect of easily collecting the support grid repulsion coefficient, which is one of the support grid dynamic impact characteristics.

In addition, when the fuel assembly is combusted in the reactor core, the support grid performs its function even in a high temperature environment, thus providing an impact test of the support grid under the high temperature conditions as well as the normal temperature test.

The present invention is not limited to the above embodiments and can be variously modified and implemented by those skilled in the art without departing from the technical gist of the present invention.

Claims (8)

A support structure fixed at a certain position, a test piece fixture for fixing a support lattice specimen to be fixed at a predetermined position of the support structure so that a collision test can be performed, and a column fixed to the support structure to support the impact hammer; Pendulum means for installing the impact hammer on the column so that the impact hammer horizontally collides with the support grid specimen at the height of the maximum kinetic energy, and adjust the height of the pendulum means and the distance between the specimen Adjuster installed on the pillar, hammer fixing means for fixing the impact hammer to maintain the potential energy at a certain height, and measuring means for measuring the impact force in the collision with the support grid specimen installed in front of the impact hammer Pendulum impact tester capable of adjusting any impact angle and impact point comprising a. The method of claim 1, The specimen fixture is fixed to the support structure and fixed to the specimen in one direction, the plate is installed to secure the specimen from the opposite side of the fixture, and the elastic force so that the plate is in contact with the support grid specimen always Pendulum impact tester capable of adjusting any impact angle and impact point, characterized in that it comprises an elastic means for providing. The method of claim 1, The pendulum means is composed of a plurality of pendulums of which the upper end is rotatably installed on the adjuster and the lower end is rotatably installed on the hammer, and the pendulum may collide while the impact hammer is horizontal to the support grid body specimen. And an analog angle conversion system is installed at a connection point of one of the pendulums to measure the angle of the pendulum according to time and at the same time obtain the repulsion coefficient of the support grid itself. Pendulum impact tester with adjustable impact point. The method of claim 1, The measuring means includes an accelerometer installed in front of the impact hammer, a cap installed to isolate the angular speedometer to isolate noise, a collision tip installed in front of the cap and colliding with the specimen, and the collision tip and cap Pendulum-type impact tester that can be adjusted to any impact angle and the impact point, characterized in that it consists of a force conversion system installed between the collision force is transmitted to collect the impact force to measure the impact force. The method of claim 1, The hammer fixing means is a pendulum formula capable of adjusting any impact angle and impact point, characterized in that consisting of a fixing means installed so as to be transported in a straight line on the support structure and a handle for inputting a driving force for transferring the electromagnet Impact tester. The method of claim 5, Pendulum impact tester capable of adjusting any impact angle and impact point, characterized in that the fixing means is an electromagnet. In the pendulum-type impact tester, which installs an impact hammer on a pendulum and freely drops it at a predetermined height and collides with the specimen of the support grid, thereby measuring the impact amount. Pendulum-type impact tester capable of adjusting any impact angle and impact point, characterized in that the furnace is installed outside the support grid body specimen to adjust the test temperature. The method of claim 7, wherein Pendulum-type impact tester capable of adjusting any impact angle and impact point, characterized in that the fan is installed inside the furnace for uniform temperature.