Reactor control rod guide tube transverse hydraulic load measuring device

Abstract

The present application relates to a kind of reactor control rod guide tube transverse hydraulic load measuring device, it includes lower guide tube assembly simulation body, force sensor;Force sensor and lower guide tube assembly simulation body are arranged in line and are connected as a whole;Force sensor includes elastomer, four groups of strain gauges, protective cover;Elastomer includes two first cambered surfaces for measuring two opposite directions moment on x axis and is symmetrically arranged in axial direction, two second cambered surfaces for measuring two opposite directions moment on y axis and is symmetrically arranged in axial direction;The center connecting line of two first cambered surfaces and two second cambered surfaces is perpendicular.Strain gauge is correspondingly arranged on two first cambered surfaces, two second cambered surfaces.The transverse hydraulic load measuring device of the present application can accurately measure the transverse hydraulic load that control rod guide tube assembly is subjected to in reactor;Reasonable proportion is simulated, so that the overall structure of measuring device is simpler;Force sensor has higher precision and linearity.

Description

Technical Field

[0001] This invention relates to the field of reactor test research technology, and in particular to a device for measuring the lateral hydraulic load of a reactor control rod guide tube. Background Technology

[0002] During nuclear reactor operation, the reactor coolant flows within the reactor pressure vessel to cool the reactor core. In-reactor flow characteristics, such as lateral hydraulic loads, are crucial inputs for reactor structural mechanics analysis, flow-induced vibration evaluation, and drive rod drop performance analysis. Due to the dense arrangement of in-reactor components and limited space, existing technologies primarily rely on numerical simulations to theoretically analyze the lateral hydraulic loads on the control rod guide tube assembly. However, there are no relevant technologies for experimentally measuring the lateral hydraulic loads on the control rod guide tube assembly. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a transverse hydraulic load measuring device for reactor control rod guide tubes, which includes a lower guide tube assembly simulator and a force sensor for mounting to a reactor upper support plate or its simulator; the force sensor and the lower guide tube assembly simulator are arranged in a straight line and connected as a whole;

[0004] The force sensor includes an elastic body and four sets of strain gauges;

[0005] The elastic body includes a first strain measurement region and a second strain measurement region distributed sequentially along its axial direction.

[0006] The first strain measurement region includes two first arc surfaces for measuring torques in two opposite directions on the x-axis, and the two first arc surfaces are axially symmetrically arranged.

[0007] The second strain measurement region includes two second arc surfaces for measuring torques in two opposite directions on the y-axis; the two second arc surfaces are arranged axially symmetrically.

[0008] The first and second arc surfaces are concave inward along the radial direction of the elastic body; the center connecting line of the two first arc surfaces is perpendicular to the center connecting line of the two second arc surfaces;

[0009] Two strain gauges are respectively connected by the center lines of the two first arc surfaces and are respectively disposed on the two first arc surfaces; the other two strain gauges are respectively connected by the center lines of the two second arc surfaces and are respectively disposed on the two second arc surfaces.

[0010] Preferably, the reactor control rod guide tube transverse hydraulic load measuring device further includes a protective cover, which is detachably fitted onto the elastomer to isolate the first strain measurement area and the second strain measurement area from the outside.

[0011] Preferably, the elastomer includes a first connecting base for connecting a reactor upper support plate or its simulator, a second connecting base for connecting to the lower guide tube assembly simulator, and a strain measuring base connected between the first and second connecting bases; the first strain measuring region and the second strain measuring region are located on the strain measuring base;

[0012] The maximum radial dimension of the strain measurement substrate is smaller than the radial dimension of the through hole on the reactor support plate or its simulator through which the control rod guide tube assembly or its simulator passes.

[0013] The maximum radial dimension of the second connecting base is less than the maximum radial dimension of the lower guide tube assembly simulator; the maximum radial dimension of the lower guide tube assembly simulator is less than the radial dimension of the through hole on the reactor upper support plate or its simulator through which the control rod guide tube assembly or its simulator passes.

[0014] Preferably, the reactor control rod guide tube transverse hydraulic load measuring device further includes a protective cover, which is detachably fitted onto the strain measuring base to isolate the first strain measuring area and the second strain measuring area from the outside.

[0015] The radial dimension of the whole formed by the protective cover and the strain measurement substrate is smaller than the radial dimension of the through hole on the reactor support plate or its simulator through which the control rod guide cylinder assembly passes, and the difference between the radial dimension of the whole formed by the protective cover and the strain measurement substrate and the radial dimension of the through hole on the reactor support plate or its simulator through which the control rod guide cylinder assembly passes is 10 to 14 mm.

[0016] Preferably, the cross-section of the strain measurement substrate, excluding the first strain measurement area and the second strain measurement area, is circular.

[0017] Preferably, the first connecting base is provided with the middle flange of the reactor control rod guide tube assembly; it is provided with a plurality of countersunk screw connection holes that penetrate its two opposite end faces.

[0018] Preferably, the thickness of the first connecting substrate is greater than the thickness of the central flange of the prototype control rod guide tube assembly within the prototype reactor.

[0019] Alternatively, the thickness of the first connecting base may be greater than the thickness of the central flange of another control rod guide tube assembly simulator within the reactor simulator, which has been scaled down by a preset ratio.

[0020] Preferably, the first connecting base is further provided with a wire hole penetrating its two opposite end faces;

[0021] Each set of strain gauges is connected to a wire for connection to the measurement and control cabinet; the wire is threaded through the wire hole.

[0022] Preferably, the second connecting base is embedded in the lower guide cylinder assembly simulation body and welded together with the lower guide cylinder assembly simulation body.

[0023] Preferably, the radial dimension of the lower guide tube assembly simulator is equal to the radial dimension of its prototype lower guide tube assembly in the prototype reactor; or the radial dimension of the lower guide tube assembly simulator is equal to the radial dimension of other lower guide tube assemblies in the reactor simulator that have been scaled down by a preset ratio.

[0024] The length of the lower guide tube assembly simulator is less than the length of its prototype lower guide tube assembly in the prototype reactor; or the length of the lower guide tube assembly simulator is less than the length of other lower guide tube assembly simulators in the reactor simulator that have been scaled down by a preset ratio.

[0025] Preferably, the lower guide cylinder assembly simulation body includes a first end and a second end opposite to each other, the first end being connected to the force sensor, and the other end opposite to it being provided with a bottom flange simulation body; the bottom flange simulation body is a solid structure.

[0026] Preferably, the elastomer is 2Cr13 stainless steel that has undergone quenching treatment.

[0027] Preferably, the strain gauge and the elastomer are connected by an adhesive layer.

[0028] Preferably, the surface of the strain gauge is provided with a first waterproof layer.

[0029] Preferably, a second waterproof layer is provided on the first waterproof layer, the first arc surface, and the second arc surface.

[0030] The present invention has at least the following beneficial effects: (1) The force sensor, in conjunction with the lower guide tube assembly simulator, can simulate the lateral hydraulic load on the control rod guide tube assembly, and measure the lateral hydraulic load on the control rod guide tube assembly in real time, so as to accurately measure the lateral hydraulic load on the control rod guide tube assembly in the pile; (2) Only by setting the lower guide tube assembly simulator corresponding to the lower guide tube assembly, the situation of the entire control rod guide tube assembly being subjected to water flow load can be approximately simulated. Thus, by adopting a reasonable proportional modeling method, the overall structure of the measuring device is relatively simple, easy to manufacture and install. (3) There are stress concentration deformation areas on the first arc surface and the second arc surface. Specifically, the area near the center connection line of the two first arc surfaces (or two second arc surfaces) is a relatively uniform area of ​​strain concentration. Therefore, the strain gauges are set on the first arc surface and the second arc surface respectively, so that the force sensor has high accuracy and linearity. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the structure of the reactor control rod guide tube lateral hydraulic load measuring device installed on the reactor upper support plate according to an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 Enlarged diagram of section B;

[0034] Figure 3 This is a structural schematic diagram of the force sensor of the reactor control rod guide tube lateral hydraulic load measuring device according to an embodiment of the present invention, viewed from a perspective.

[0035] Figure 4 yes Figure 3 A schematic diagram of the force sensor from another perspective;

[0036] Figure 5 yes Figure 3 The diagram shows the structure of the force sensor as viewed from direction A.

[0037] Figure 6 This is a schematic diagram of the force sensor of the reactor control rod guide tube lateral hydraulic load measuring device according to an embodiment of the present invention from another perspective. Detailed Implementation

[0038] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] In a reactor vessel, the reactor control rod guide tube is formally called the control rod guide tube assembly. The control rod guide tube assembly includes an upper guide tube assembly, a lower guide tube assembly, and a central flange connecting the upper and lower guide tube assemblies. For example... Figure 1 , Figure 2 As shown, the upper guide tube assembly (not shown) is located on the upper side of the reactor upper support plate 7, and the lower guide tube assembly (not shown, but the location of the lower guide tube assembly simulator 2 in the figure can be referenced) is located on the lower side of the reactor upper support plate 7; the reactor upper support plate 7 is provided with a first through hole 71 for the control rod guide tube assembly to pass through (e.g., Figure 2As shown, an instrument grid 8 is installed on the upper surface of the reactor support plate 7. The instrument grid 8 also has a second through hole for the control rod guide tube assembly to pass through, and the radial dimension of the second through hole is larger than the radial dimension of the first through hole 71. The first through hole 71 and the second through hole are aligned, forming a step due to the difference in radial dimensions. The middle flange is adapted to the second through hole on the instrument grid 8 (not shown, but refer to the location of the first connecting base 101 in the figure). Countersunk screws pass through the middle flange and are fixed to the reactor support plate 7 to fix the middle flange to the reactor support plate 7. The lower guide tube assembly is connected to the middle flange and passes through the first through hole 71, with one part located inside the first through hole 71 and the other part located outside the first through hole 71. That is, the upper guide tube assembly and the lower guide tube assembly are connected through the middle flange, and the upper guide tube assembly and the lower guide tube assembly are located on the upper and lower sides of the reactor support plate 7, respectively. For ease of understanding, the following text will use "first through hole 71" instead of describing "through hole on reactor support plate 7 or its simulator for the control rod guide tube assembly to pass through".

[0040] like Figures 1 to 6 As shown, an embodiment of the reactor control rod guide tube lateral hydraulic load measuring device (hereinafter sometimes referred to as the measuring device for ease of description) includes a force sensor 1 and a lower guide tube assembly simulator 2. The force sensor 1 and the lower guide tube assembly simulator 2 are arranged in a straight line and connected as a whole. The lower guide tube assembly simulator 2 is used to simulate the control rod guide tube assembly. Specifically, based on theoretical analysis and actual measurements, the upper guide tube assembly is located on the upper side of the reactor upper support plate 7 and close to the reactor upper support plate 7. The flow rate here is small and it is located in a dead water zone, so the water flow load it receives is very small and can be ignored. Therefore, by simply setting the lower guide tube assembly simulator 2 corresponding to the lower guide tube assembly, the water flow load on the entire control rod guide tube assembly can be approximately simulated. Thus, by adopting a reasonable scaling method, the overall structure of the measuring device is relatively simple and easy to manufacture and install. The force sensor 1 is used to measure the torque received by the lower guide tube assembly simulator 2 in two vertical directions. It should be noted that the scale modeling method refers to modeling the prototype reactor and its internal components according to a preset scale.

[0041] like Figures 3 to 4 As shown, the force sensor 1 includes an elastic body 10 and four sets of strain gauges 11. Among them, Figure 4 It is Figure 3 A schematic diagram of the structure as viewed from a 90-degree angle.

[0042] The elastic body 10 has a first strain measurement region and a second strain measurement region distributed sequentially along its axial direction. The first strain measurement region and the second strain measurement region are used for strain measurement.

[0043] The first strain measurement area includes two regions for measuring strain in two opposite directions on the x-axis. Figure 3 The first arc surface 21 of the x1 and x2 torques is arranged symmetrically along the axis. That is, the two first arc surfaces 21 are arranged symmetrically with respect to the central axis of the length direction of the elastic body 10.

[0044] The second strain measurement area includes two regions for measuring strain in two opposite directions on the y-axis. Figure 4 The second arc surface 22 of the torque (y1 and y2) in the elastic body 10. The two second arc surfaces 22 are symmetrically arranged axially. That is, the two first arc surfaces 21 are symmetrically arranged with respect to the central axis of the length direction of the elastic body 10.

[0045] The first arc surface 21 and the second arc surface 22 are concave inward along the radial direction of the elastic body 10. Specifically, the first arc surface 21 and the second arc surface 22 are concave inward along the radial direction of the elastic body 10 towards the central axis of the length direction of the elastic body 10.

[0046] It should be noted that the x-axis and y-axis are two mutually perpendicular reference axes. This can be compared to the fact that in a reactor vessel, both the x-axis and y-axis are parallel to the radial direction of the reactor vessel, that is, the two-dimensional plane formed by the x-axis and y-axis is parallel to the radial direction of the reactor vessel; or, in other words, both the x-axis and y-axis are parallel to the reactor support plate 7 or its simulation body, that is, the two-dimensional plane formed by the x-axis and y-axis is parallel to the reactor support plate 7 or its simulation body.

[0047] The center-connecting line of the two first arc surfaces 21 is perpendicular to the center-connecting line of the two second arc surfaces 22, which corresponds to the x-axis being perpendicular to the y-axis.

[0048] It should be noted that each first arc surface 21 has four consecutively connected edge lines, which together form the edge contour of each first arc surface 21. The intersection point of adjacent edge lines on each first arc surface 21 is a corner point. Along the direction in which the four edge lines of each first arc surface 21 are consecutively connected, a first corner point, a second corner point, a third corner point, and a fourth corner point are formed sequentially. The first corner point and the third corner point are connected to form a first diagonal, and the second corner point and the fourth corner point are connected to form a second diagonal. The intersection point of the first diagonal and the second diagonal is defined as the center point of each first arc surface 21. The straight line formed by connecting the center points of two first arc surfaces 21 is the center-connecting line of the two first arc surfaces 21. Similarly, each second arc surface 22 has four consecutively connected edge lines, which together form the edge of each second arc surface 22. The intersection of adjacent edge lines on each second arc surface 22 is a corner point. Along the direction in which the four edge lines of each second arc surface 22 connect sequentially, a fifth, sixth, seventh, and eighth corner point are formed. The fifth and seventh corner points are connected to form the third diagonal, and the sixth and eighth corner points are connected to form the fourth diagonal. The intersection of the third and fourth diagonals is defined as the center point of each second arc surface 22. The straight line connecting the center points of two second arc surfaces 22 is the center-connecting line between the two second arc surfaces 22.

[0049] The center connecting lines of the two sets of strain gauges 11 corresponding to the two first arc surfaces 21 are respectively disposed on the two first arc surfaces 21; the center connecting lines of the two sets of strain gauges 11 corresponding to the two second arc surfaces 22 are respectively disposed on the two second arc surfaces 22. Specifically, the central axes of the two sets of strain gauges 11 in the thickness direction may coincide with the center connecting lines of the two first arc surfaces 21; the central axes of the other two sets of strain gauges 11 in the thickness direction may coincide with the center connecting lines of the two second arc surfaces 22. A set of strain gauges 11 may include one or more strain gauges 11.

[0050] The arrangement of the first arc surface 21 and the second arc surface 22 reduces the equivalent diameter of the elastic body 10, thus improving the sensor's sensitivity to torque. Simulation calculations show that stress concentration deformation regions exist on the first arc surface 21 and the second arc surface 22. Specifically, the region near the center line connecting the two first arc surfaces 21 (or the two second arc surfaces 22) is a region with relatively uniform strain concentration. The more uniform the strain concentration, the smaller the deviation of the measured strain value. Therefore, strain gauges 11 are correspondingly arranged on the first arc surface 21 and the second arc surface 22, giving the force sensor 1 of this invention high linearity and accuracy. Actual measurements show an uncertainty Urel = 0.33% and a confidence factor k = 2.

[0051] That is, a set of strain gauges 11 is installed on each first arc surface 21; a set of strain gauges 11 is installed on each second arc surface 22. Thus, after the four sets of strain gauges 11 are installed on each arc surface, they can measure the torque in four directions on a two-dimensional plane. Applied to the reactor support column or reactor support column assembly simulator, this allows for the measurement of the lateral hydraulic load on the reactor support column or reactor support column assembly simulator, more accurately reflecting the lateral hydraulic load experienced by the reactor support column within the reactor vessel. The strain gauge 11 can be of the HBM SG 3 / 350E LKs-6 type, which has the advantage of fast frequency response.

[0052] The measurement principle is as follows: The force sensor 1 of this invention is placed inside the reactor vessel, for example, below the support plate 7 on the reactor, in an underwater environment. According to the Wheatstone bridge principle, when the force sensor 1 is subjected to a hydraulic load, the torque is transmitted to the location of the strain gauge 11, causing the strain gauge 11 to change its resistance due to strain. The Wheatstone bridge on the strain gauge 11 converts the minute resistance change into a measurable voltage signal, which is then amplified and finally converted into a torque signal by the acquisition system based on the previously calibrated parameters. In addition, the Wheatstone bridge can also achieve temperature error compensation, and the special nickel metal on it can correct the small residual error remaining during strain measurement. Furthermore, the force sensor 1 of the present invention can be calibrated in the following way: the assembled force sensor 1 is installed on a calibration stand, and the main force points of hydraulic impact are gradually loaded (0-75 Nm). The output value of the force sensor 1 and the output value of the standard torque sensor (HBM T10FS, 0.01%) are recorded. After comparison, the linearity, hysteresis and other parameters of the force sensor 1 can be obtained. Based on the linearity, hysteresis and other parameters, the force sensor 1 is adjusted to meet the accuracy requirements (Urel = 0.33%, k = 2).

[0053] In summary, the present invention has at least the following beneficial effects: (1) The force sensor 1, in conjunction with the lower guide tube assembly simulator 2, can simulate the lateral hydraulic load on the control rod guide tube assembly and measure the lateral hydraulic load on the control rod guide tube assembly in real time, so as to more accurately reflect the lateral hydraulic load on the control rod guide tube assembly in the pile; (2) Only the lower guide tube assembly simulator 2 needs to be set for the lower guide tube assembly to approximately simulate the water flow load on the entire control rod guide tube assembly. Thus, by adopting a reasonable proportional modeling method, the overall structure of the measuring device is simpler and easier to manufacture and install. (3) There are stress concentration deformation areas on the first arc surface 21 and the second arc surface 22. Specifically, the area near the center connection line of the two first arc surfaces 21 (or the two second arc surfaces 22) is a relatively uniform area of ​​strain concentration. Therefore, the strain gauge 11 is set on the first arc surface 21 and the second arc surface 22 respectively, so that the force sensor 1 has high accuracy and linearity. (4) The structure of the force sensor 1 of the present invention is simpler than that of existing force sensors 1 such as cross beam type, cylindrical type, beam column type and Stewar platform type force sensor 1, and is correspondingly easier to miniaturize in order to adapt to the situation of dense arrangement of internal components and small space.

[0054] In this embodiment, the measuring device also includes a protective cover 3, which is detachably fitted onto the elastic body 10. This protective cover isolates the first and second strain measurement areas from the outside environment, enabling the force sensor 1 to be waterproof, resistant to water flow impact, and protected against electromagnetic interference. This prevents water flow and electromagnetic interference from adversely affecting measurement accuracy, and is particularly suitable for the underwater environment inside a reactor vessel. Simultaneously, it facilitates the removal of the protective cover 3 for disassembly and assembly of the strain gauge 11, making inspection and maintenance easier. Specifically, screw holes are provided on the elastic body 10 and the protective cover 3. After passing countersunk screws through these holes and tightening them, the protective cover 3 is fixed to the elastic body 10.

[0055] In this embodiment, the elastomer 10 includes a first connecting base 101, a second connecting base 102, and a strain measuring base 103 connected between the first connecting base 101 and the second connecting base 102. The first strain measuring region and the second strain measuring region are located on the strain measuring base 103. Correspondingly, a protective cover 3 is detachably fitted onto the strain measuring base 103, and the protective cover 3 is spaced apart from both the first connecting base 101 and the second connecting base 102; the protective cover 3 is also spaced apart from the first strain measuring region and the second strain measuring region on the strain measuring base 103. The first connecting base 101 is used to connect the reactor support plate 7 or its simulator to fix the measuring device as a whole. The maximum radial dimension of the strain measuring base 103 is smaller than the radial dimension of the first through hole 71 on the reactor support plate 7 or its simulator. The maximum radial dimension of the second connecting base 102 is smaller than the maximum radial dimension of the lower guide tube assembly simulator 2. The maximum radial dimension of the lower guide tube assembly simulator 2 is smaller than the radial dimension of the first through hole 71 on the reactor support plate 7 or its simulator. It should be noted that the strain measurement base 103, the second connecting base 102, and the lower guide tube assembly simulator 2 are not necessarily structures with equal radial dimensions everywhere. In particular, the radial dimensions at the first arc surface 21 and the second arc surface 22 of the strain measurement base 103 vary along its axial direction. Therefore, the maximum radial dimension of the strain measurement base 103 refers to the radial dimension value at the position where its axial radial dimension is the largest. Similarly, the maximum radial dimension of the second connecting base 102 refers to the radial dimension value at the position where its axial radial dimension is the largest; the maximum radial dimension of the lower guide tube assembly simulator 2 refers to the radial dimension value at the position where its axial radial dimension is the largest.

[0056] Specifically, during installation, the first connecting base 101 is mounted onto the reactor upper support plate 7 or its simulator. The strain measuring base 103 and the second connecting base 102 pass through the first through hole 71 on the reactor upper support plate 7 or its simulator by means of a smaller radial dimension, with the entire strain measuring base 103 located within the first through hole 71. The second connecting base 102 is connected to the lower guide tube assembly simulator 2 as a whole. The lower guide tube assembly simulator 2 is located below the reactor upper support plate 7 or its simulator, spaced apart from it. The maximum radial dimension of both the strain measuring base 103 and the lower guide tube assembly simulator 2 is smaller than the radial dimension of the first through hole 71 on the reactor upper support plate 7 or its simulator. This allows the measuring device to be mounted as a whole onto the reactor upper support plate 7 or its simulator from top to bottom, ensuring no unnecessary contact interference with the reactor upper support plate 7 or its simulator.

[0057] like Figure 3 , Figure 4As shown, the strain measurement base 103 may include a first part, a second part, and a third part with different radial dimensions. The first part of the strain measurement base 103 is connected to a first connecting base 101; the third part of the strain measurement base 103 is connected to a second connecting base 102; and the second part of the strain measurement base 103 is connected between the first and third parts. The first strain measurement area and the second strain measurement area are located on the second part of the strain measurement base 103. The radial dimension of the second part of the strain measurement base 103 is smaller than the radial dimensions of the first and third parts. Further, a mounting hole 104 for connecting a protective cover 3 is provided on the first part of the strain measurement base 103. A countersunk screw passes through the protective cover 3 and the mounting hole 104 to install the protective cover 3 onto the first part of the strain measurement base 103. Thus, because the second part of the strain measurement base 103 has a smaller radial dimension, a gap is formed between it and the protective cover 3, avoiding contact interference between the protective cover 3 and the first and second strain measurement areas.

[0058] Furthermore, the radial dimension of the entire structure formed by the protective shield 3 and the strain measurement substrate 103 is smaller than the radial dimension of the through hole (i.e., the first through hole 71) on the reactor support plate 7 or its simulator through which the control rod guide tube assembly or its simulator passes. The difference between the radial dimension of the entire structure formed by the protective shield 3 and the strain measurement substrate 103 and the radial dimension of the through hole (i.e., the first through hole 71) on the reactor support plate 7 or its simulator through which the control rod guide tube assembly or its simulator passes is 10–14 mm. That is, the gap width between the inner wall surfaces of the protective shield 3 and the first through hole 71 on the reactor support plate 7 or its simulator is 5–7 mm. In addition, there is a gap width of at least 2 mm between the strain measurement substrate 103 and the protective shield 3. Specifically, the radial dimension of the whole formed by the strain measuring base 103 and the protective cover 3 can be adjusted by adjusting the radial dimension of the strain measuring base 103. If the radial dimension of the strain measuring base 103 is too large, the radial dimension of the whole formed by the strain measuring base 103 and the protective cover 3 will be too large, which will cause contact interference between the protective cover 3 and the first through hole 71 on the reactor support plate 7 or its simulation body, affecting the accuracy of the measurement results. If the radial dimension of the strain measuring base 103 is too small, its stiffness will be too small, affecting the overall stiffness of the elastic body 10. Through theoretical analysis and actual measurement, when the difference between the radial dimension of the integral formed by the strain measuring substrate 103 and the protective cover 3 and the radial dimension of the first through hole 71 on the reactor support plate 7 or its simulator is 10 to 14 mm, that is, when the gap width between the integral formed by the strain measuring substrate 103 and the protective cover 3 and the inner wall surface of the first through hole 71 on the reactor support plate 7 or its simulator is 5 to 7 mm, the risk of contact interference between the protective cover 3 and the inner wall surface of the first through hole 71 can be minimized while meeting the stiffness requirements.

[0059] Furthermore, the protective cover 3 includes two arc-shaped protective cover sub-units, which are joined together to form a cylindrical protective cover 3. In this embodiment, the maximum radial dimension of the strain measurement base 103 is smaller than both the radial dimension of the first connecting base 101 and the radial dimension of the second connecting base 102. Therefore, setting the protective cover 3 as a docking structure can better adapt to the structural features of the elastomer 10, making it easier to install the protective cover 3 onto the elastomer 10.

[0060] Furthermore, the cross-section of the strain measurement base 103, excluding the first and second strain measurement areas, is circular. However, the cross-sections of the second connecting base 102 and the first connecting base 101 are non-circular, corresponding to the shape of their prototype lower guide cylinder assembly. Specifically, the upper and lower guide tube assemblies of the control rod guide tube assembly in some nuclear power plants have roughly rectangular cross-sections. Considering that the cross-section of the prototype lower guide tube assembly is roughly rectangular, and the first through hole 71 is circular, even if the strain measurement base 103 and the inner wall of the first through hole 71 are spaced apart, if the rectangular structure of the prototype lower guide tube assembly is completely simulated, under the action of water flow, contact interference will easily occur between the strain measurement base 103 and the inner wall of the first through hole 71 on the reactor support plate 7 or its simulator, affecting the accuracy of the measurement results. Therefore, setting the cross-section of the strain measurement base 103 except for the first and second strain measurement areas to be circular can effectively reduce the risk of contact interference between the elastomer 10 and the inner wall of the first through hole 71 on the reactor support plate 7 or its simulator. At the same time, the first connecting base 101 and the second connecting base 102 still correspond to the rectangular structure of the prototype lower guide tube assembly, maintaining the structural simulation of the prototype lower guide tube assembly. In summary, by comprehensively considering the degree of structural simulation of the elastomer 10 and the risk of contact interference between the elastomer 10 and other in-reactor components, and employing a reasonable scaling method, we can ensure that the elastomer 10 has a good degree of structural simulation while keeping the risk of contact interference with other in-reactor components within a low reliability range. It should be noted that "cross-section" refers to the cross-section obtained by drawing a section line from the radial direction of the component. "Radial" refers to the direction perpendicular to the central axis of the component's length.

[0061] Furthermore, the first connecting base 101 is provided with a central flange corresponding to the reactor control rod guide tube assembly, which is used to improve the degree of structural simulation of the elastomer 10. As mentioned above, the connection between the upper guide tube assembly and the lower guide tube assembly of the prototype reactor is achieved by passing countersunk screws through the central flange and fixing them to the reactor upper support plate 7. Correspondingly, the first connecting base 101 is also provided with a plurality of countersunk screw connection holes 5 penetrating its two opposite end faces, so that the countersunk screws can pass through and be fixed to the reactor upper support plate 7 or its simulation body, thereby connecting the first connecting base 101 to the reactor upper support plate 7 or its simulation body.

[0062] Furthermore, considering both the stiffness of the elastomer 10 and the degree of structural simulation of the elastomer 10, when the measuring device is used inside a prototype reactor, the thickness of the first connecting base 101 is greater than the thickness of the central flange of the prototype control rod guide tube assembly inside the prototype reactor. Alternatively, when the measuring device is used inside a reactor simulator scaled down by a preset ratio, the thickness of the first connecting base 101 is greater than the thickness of the central flange of other control rod guide tube assembly simulators scaled down by a preset ratio inside the reactor simulator.

[0063] It should be noted that within the reactor vessel, there are dozens of control rod guide tube assemblies. A "scaled-down reactor simulator" refers to a reactor simulator scaled down relative to the prototype reactor while maintaining geometric similarity; for example, a reactor simulator scaled down to a 1:5 ratio relative to the prototype reactor while maintaining geometric similarity. "Other scaled-down control rod guide tube assembly simulators" differs from the control rod guide tube assembly simulators in this invention. These refer to other control rod guide tube assembly simulators on the scaled-down reactor simulator, excluding the control rod guide tube assembly simulators installed within it. These other control rod guide tube assembly simulators are scaled down relative to the prototype control rod guide tube assembly while maintaining geometric similarity, in order to simulate the prototype reactor as realistically as possible. When the measuring device of the present invention is used in a reactor simulator that has been scaled down by a preset ratio, its first connecting base 101 and the middle flange of the prototype control rod guide tube assembly are scaled down according to a certain ratio on the basis of satisfying geometric similarity, and its thickness is increased by a certain scale to improve the stiffness of the first connecting base 101. This ensures that while improving the degree of structural simulation of the elastic body 10, the elastic body 10 as a whole has reliable stiffness, reducing the risk of contact interference with other reactor components under the impact of water flow.

[0064] In this embodiment, the first connecting base 101 is also provided with wire holes 4 penetrating its two opposite end faces. Each set of strain gauges 11 is connected with wires for connecting to the measurement and control cabinet. The wires are inserted into the wire holes 4 and closely attached to the instrument grid 8 (or instrument grid simulation) on the reactor support plate 7 (or reactor support plate simulation body), and then led out of the reactor vessel to connect to the measurement and control cabinet, thereby realizing the signal transmission of the strain gauges 11. Thus, the arrangement of the wires can better adapt to the situation of dense arrangement of reactor internal components and limited space, and hardly affects the simulation of the flow field inside the prototype reactor, with high accuracy of working condition reproduction.

[0065] In this embodiment, the second connecting base 102 is embedded in the lower guide cylinder assembly simulation body 2 and welded to it as a whole, resulting in a simple, reliable structure with good overall integrity. Specifically, the lower guide cylinder assembly simulation body 2 can be a hollow structure with an opening on its end face. The second connecting base 102 is partially inserted into the lower guide cylinder assembly simulation body 2 through the opening, and then the connection between the second connecting base 102 and the lower guide cylinder assembly simulation body 2 is welded together. This ensures a firm connection between the lower guide cylinder assembly simulation body 2 and the second connecting base 102, further ensuring that the measuring device has good overall rigidity and thus ensuring the accuracy of the measurement results.

[0066] In this embodiment, the radial dimension of the lower guide tube assembly simulator 2 is equal to the radial dimension of its prototype lower guide tube assembly within the prototype reactor. Alternatively, the radial dimension of the lower guide tube assembly simulator 2 is equal to the radial dimension of other lower guide tube assembly simulators within a reactor simulator that have been scaled down to a preset scale. It should be noted that "scaled down reactor simulator" refers to a reactor simulator scaled down relative to the prototype reactor at a preset scale while satisfying geometric similarity; for example, a reactor simulator scaled down relative to the prototype reactor at a 1:5 ratio while satisfying geometric similarity. "Other scaled down lower guide tube assembly simulators" are distinct from the lower guide tube assembly simulator 2 in this invention; they refer to other lower guide tube assembly simulators 2 on the scaled down reactor simulator besides the one installed within it. These other lower guide tube assembly simulators are scaled down relative to their prototype lower guide tube assemblies at a preset scale while satisfying geometric similarity, in order to simulate the prototype reactor as realistically as possible.

[0067] That is, the radial dimensions of the lower guide tube assembly simulator 2 completely simulate the configuration of its prototype lower guide tube assembly. The length of the lower guide tube assembly simulator 2 is less than the length of its prototype lower guide tube assembly in the prototype reactor. Or the length of the lower guide tube assembly simulator 2 is less than the length of other lower guide tube assemblies in the reactor simulator that have been scaled down by a preset ratio. In other words, the length of the lower guide tube assembly simulator 2 does not completely simulate the configuration of its prototype lower guide tube assembly, but is shortened. Inside the reactor vessel, the lower end of the lower guide tube assembly simulator 2 is fixedly connected to the lower core plate. After the length of the lower guide tube assembly simulator 2 of the present invention is shortened, it is spaced apart from the upper core plate, so that the entire measuring device can be suspended on the upper support plate 7 of the reactor, reserving a reasonable space for load deformation of the lower guide tube assembly simulator 2, eliminating the influence of the force of the upper core plate on the lower guide tube assembly simulator 2, and further ensuring the accuracy of the measurement results. For example, in a reactor simulator scaled down to a 1:5 ratio, the length of the lower guide tube assembly simulator 2 is less than the length of other lower guide tube assembly simulators scaled down to a preset ratio in the reactor simulator, and the difference between the length of the lower guide tube assembly simulator 2 and the length of other lower guide tube assembly simulators scaled down to a preset ratio in the reactor simulator is 3 to 5 mm.

[0068] In this embodiment, as Figure 1 As shown, the lower guide tube assembly simulator 2 includes a first end and a second end opposite to each other. The first end is connected to the force sensor 1, and the other end opposite to it is provided with a bottom flange simulator 6. The bottom flange simulator 6 of the lower guide tube assembly simulator 2 is a solid structure. Specifically, the lower end of the prototype lower guide tube assembly is fixedly installed to the reactor core upper plate after passing through the bottom flange with a pin, so the bottom flange of the lower end of the prototype lower guide tube assembly has a pin hole. Unlike the prototype lower guide tube assembly, the bottom flange simulator 6 of the lower guide tube assembly simulator 2 of the present invention, while simulating the outer contour of the bottom flange of the lower end of the prototype lower guide tube assembly, eliminates the pin hole on the bottom flange simulator 6. Therefore, the bottom flange simulator 6 of the lower guide tube assembly simulator 2 is a solid structure, which can avoid the water flow changing the flow field distribution inside the reactor core after passing through the pin hole and affecting the accuracy of the simulation test.

[0069] In this embodiment, the elastomer 10 is made of quenched 2Cr13 stainless steel, which provides suitable stiffness to improve the upper limit of the force sensor 1's measurement range. Testing shows that the upper limit of the force sensor 1's measurement range can reach ±75 Nm, thus meeting the measurement requirements under in-reactor overspeed conditions. The structure and material of the elastomer 10 comprehensively balance various performance aspects such as stiffness, sensitivity, linearity, and interdimensional decoupling. Structurally, strain gauges 11 are correspondingly arranged on the first arc surface 21 and the second arc surface 22, giving the force sensor 1 of this invention high linearity and accuracy. The elastomer 10, made of quenched 2Cr13 stainless steel, has an upper limit of ±75 Nm, thus meeting the measurement requirements under in-reactor overspeed conditions, resulting in superior overall performance of the force sensor 1 and good adaptability to the reactor environment.

[0070] In this embodiment, the strain gauge 11 and the elastomer 10 are connected by an adhesive layer to ensure a tight connection between the strain gauge 11 and the elastomer 10.

[0071] Furthermore, the adhesive layer is made of HBM310S type adhesive. The adhesive layer is bonded between the strain gauge 11 and the elastomer 10, or the adhesive layer is applied between the strain gauge 11 and the elastomer 10 after undergoing at least one layer of high-temperature curing. Specifically, the multi-layer high-temperature curing treatment means that each layer of adhesive is applied to the strain gauge 11 or the elastomer 10 and then cured at high temperature. When the adhesive layer is made of HBM310S type adhesive, and the adhesive layer is bonded between the strain gauge 11 and the elastomer 10 after multi-layer high-temperature curing, the adhesive layer becomes more robust, achieving long-term waterproofing and dustproofing. Testing shows that the effective waterproofing and dustproofing lasts for more than one month, and the waterproofing and dustproofing effect reaches the IP68 standard (the highest level of dustproof and waterproof rating in GB / T4208-2017 enclosure protection ratings), eliminating the need for daily maintenance and offering superior convenience.

[0072] In this embodiment, a first waterproof layer is provided on the surface of the strain gauge 11, which plays a role in waterproofing and protecting the surface of the strain gauge 11.

[0073] Furthermore, the material of the first waterproof layer is HBMPU140 type adhesive. The first waterproof layer is applied to the surface of the strain gauge 11, or the first waterproof layer is formed on the surface of the strain gauge 11 after at least one layer of adhesive is cured at high temperature. The multi-layer adhesive high-temperature curing treatment specifically means that each layer of adhesive is applied to the surface of the strain gauge 11 and then cured at high temperature. When the material of the first waterproof layer is HBMPU140 type adhesive, and the first waterproof layer is formed on the surface of the strain gauge 11 after multi-layer adhesive high-temperature curing, the first waterproof layer is more robust, thus achieving long-term waterproofing and dustproofing. Testing shows that the effective waterproofing and dustproofing time can reach more than one month, and the waterproofing and dustproofing effect can reach the IP68 standard (the highest level of dustproof and waterproof rating in GB / T 4208-2017 enclosure protection ratings), eliminating the need for daily maintenance and offering better convenience.

[0074] In this embodiment, a second waterproof layer is provided on the first waterproof layer, the first arc surface 21, and the second arc surface 22, which provides further waterproof protection for the surfaces of the first waterproof layer, the first arc surface 21, and the second arc surface 22.

[0075] Furthermore, the material of the second waterproof layer is HBMX120 type adhesive. The second waterproof layer is applied to the first waterproof layer, the first curved surface 21, and the second curved surface 22, or the second waterproof layer is formed on the first waterproof layer, the first curved surface 21, and the second curved surface 22 through a high-temperature curing treatment with at least one layer of adhesive. Specifically, the high-temperature curing treatment with multiple layers of adhesive means that a high-temperature curing treatment is performed after each layer of adhesive is applied to the first waterproof layer, the first curved surface 21, and the second curved surface 22. When the material of the second waterproof layer is HBMX120 type adhesive, and the second waterproof layer is formed on the first waterproof layer, the first curved surface 21, and the second curved surface 22 after high-temperature curing treatment with multiple layers of adhesive, the second waterproof layer becomes more robust, thus achieving long-term waterproofing and dustproofing. Testing shows that the effective duration of waterproofing and dustproofing can reach more than one month, and the waterproofing and dustproofing effect can reach the IP68 standard (the highest level of dustproof and waterproof rating in GB / T 4208-2017 enclosure protection ratings), eliminating the need for daily maintenance and offering superior convenience.

[0076] Specifically, the strain gauge 11 can be first installed onto the first arc surface 21 and the second arc surface 22 using an adhesive layer. Then, a first waterproof layer is formed by coating or curing the adhesive at high temperature on the surface of the strain gauge 11. Finally, a second waterproof layer is formed by coating or curing the adhesive together on the first waterproof layer, the first arc surface 21, and the second arc surface 22. Thus, the strain gauge 11, the first arc surface 21, and the second arc surface 22 are all effectively waterproofed, ensuring that the high accuracy and linearity of the sensor are not adversely affected by the external environment.

[0077] In this embodiment, the protective cover 3 is made of stainless steel. Further, the protective cover 3 can be made of 304 stainless steel or 306L stainless steel.

[0078] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A device for measuring the lateral hydraulic load of a reactor control rod guide tube, characterized in that, Includes a lower guide tube assembly simulator (2) and a force sensor (1) for mounting to a reactor upper support plate (7) or its simulator; the force sensor (1) and the lower guide tube assembly simulator (2) are arranged in a straight line and connected as a whole; The force sensor (1) includes an elastomer (10) and four strain gauges (11). The elastic body (10) includes a first strain measurement region and a second strain measurement region distributed sequentially along its axial direction; The first strain measurement area includes two first arc surfaces (21) for measuring the torques in two opposite directions on the x-axis, and the two first arc surfaces (21) are axially symmetrically arranged; The second strain measurement region includes two second arc surfaces (22) for measuring the torques in two opposite directions on the y-axis; the two second arc surfaces (22) are arranged axially symmetrically. The first arc surface (21) and the second arc surface (22) are concave in the radial direction of the elastic body (10); the center connecting line of the two first arc surfaces (21) is perpendicular to the center connecting line of the two second arc surfaces (22); Two strain gauges (11) are respectively disposed on the two first arc surfaces (21) with their center connecting lines respectively; the other two strain gauges (11) are respectively disposed on the two second arc surfaces (22) with their center connecting lines respectively. The elastomer (10) includes a first connecting base (101) connecting the reactor upper support plate (7) or its simulator, a second connecting base (102) connecting the lower guide tube assembly simulator (2), and a strain measuring base (103) connecting the first connecting base (101) and the second connecting base (102); the first strain measuring region and the second strain measuring region are located on the strain measuring base (103); the maximum radial dimension of the strain measuring base (103) is smaller than the radial dimension of the through hole on the reactor upper support plate (7) or its simulator through which the control rod guide tube assembly or its simulator passes, and the entire strain measuring base (103) is located within the through hole; The lower guide cylinder assembly simulation body (2) has a hollow structure, and the second connecting base (102) is embedded in the lower guide cylinder assembly simulation body (2) and welded together with the lower guide cylinder assembly simulation body (2); The length of the lower guide tube assembly simulator (2) is less than the length of its prototype lower guide tube assembly in the prototype reactor; or the length of the lower guide tube assembly simulator (2) is less than the length of other lower guide tube assembly simulators in the reactor simulator that have been scaled down by a preset ratio.

2. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The reactor control rod guide tube transverse hydraulic load measuring device also includes a protective cover (3), which is detachably sleeved on the elastomer (10) to isolate the first strain measurement area and the second strain measurement area from the outside.

3. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The maximum radial dimension of the second connecting base (102) is smaller than the maximum radial dimension of the lower guide tube assembly simulator (2); the maximum radial dimension of the lower guide tube assembly simulator (2) is smaller than the radial dimension of the through hole on the reactor upper support plate (7) or its simulator through which the control rod guide tube assembly or its simulator passes.

4. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The reactor control rod guide tube transverse hydraulic load measuring device also includes a protective cover (3), which is detachably sleeved on the strain measuring base (103) to isolate the first strain measuring area and the second strain measuring area from the outside. The radial dimension of the whole formed by the protective cover (3) and the strain measurement substrate (103) is smaller than the radial dimension of the through hole on the reactor support plate (7) or its simulator through which the control rod guide cylinder assembly passes, and the difference between the radial dimension of the whole formed by the protective cover (3) and the strain measurement substrate (103) and the radial dimension of the through hole on the reactor support plate (7) or its simulator through which the control rod guide cylinder assembly passes is 10~14mm.

5. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The cross-section of the strain measurement substrate (103) is circular except for the first strain measurement area and the second strain measurement area.

6. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The first connecting base (101) is provided with the middle flange of the reactor control rod guide tube assembly; it is provided with a plurality of countersunk screw connection holes (5) that penetrate its two opposite end faces.

7. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 6, characterized in that, The thickness of the first connecting base (101) is greater than the thickness of the central flange of the prototype control rod guide tube assembly in the prototype reactor. Alternatively, the thickness of the first connecting base (101) may be greater than the thickness of the central flange of another control rod guide tube assembly simulator within the reactor simulator, which has been scaled down by a preset ratio.

8. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The first connecting base (101) is also provided with a wire hole (4) that passes through its two opposite end faces. Each strain gauge (11) is connected to a wire for connection to the measurement and control cabinet; the wire is threaded through the wire hole (4).

9. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The radial dimension of the lower guide tube assembly simulator (2) is equal to the radial dimension of its prototype lower guide tube assembly in the prototype reactor; or the radial dimension of the lower guide tube assembly simulator (2) is equal to the radial dimension of other lower guide tube assemblies in the reactor simulator that have been scaled down by a preset ratio.

10. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 1, characterized in that, The lower guide cylinder assembly simulation body (2) includes a first end and a second end opposite to each other. The first end is connected to the force sensor (1), and the other end opposite to it is provided with a bottom flange simulation body (6). The bottom flange simulation body (6) is a solid structure.

11. The reactor control rod guide tube transverse hydraulic load measuring device according to any one of claims 1 to 10, characterized in that, The elastomer (10) is 2Cr13 stainless steel that has been quenched.

12. The reactor control rod guide tube transverse hydraulic load measuring device according to any one of claims 1 to 10, characterized in that, The strain gauge (11) and the elastomer (10) are connected by an adhesive layer.

13. The reactor control rod guide tube transverse hydraulic load measuring device according to any one of claims 1 to 10, characterized in that, The surface of the strain gauge (11) is provided with a first waterproof layer.

14. The reactor control rod guide tube transverse hydraulic load measuring device according to claim 13, characterized in that, A second waterproof layer is provided on the first waterproof layer, the first arc surface (21), and the second arc surface (22).

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