A method for measuring thermal deformation of a plug in a reactor

Abstract

The present invention provides a method for measuring the thermal deformation of a reactor plug, relating to the field of nuclear energy technology. The method comprises establishing a three-dimensional coordinate system based on a first three-dimensional control point fixed in the environment, providing a reference target and laser measurement equipment on the reactor top shield, and providing a detection target on the plug. The laser measurement equipment is used to measure the reference target and the detection target in both the cold and heated states of the reactor pit, and the thermal deformation of the plug is calculated based on the detection target results. The present invention uses laser measurement equipment for detection, which has high detection efficiency and accuracy. The reference target can offset the impact of thermal deformation of the reactor top shield on the laser measurement equipment, thereby ensuring the accuracy of the detection results.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear energy, in particular to a method for measuring thermal deformation of a plug in a reactor. Background Art

[0002] In a nuclear reactor, a plug is a rotating component used for installing control rod drive mechanisms and refueling machines. During reactor operation, the plug's temperature rises, causing thermal deformation and, in turn, positional changes that can affect the operation of related equipment. For example, deformation of the plug in a refueling machine can cause the refueling machine to shift position. Failure to accurately measure this deformation can prevent the refueling machine's associated mechanisms from accurately determining its position, affecting the accuracy of subsequent operations.

[0003] However, due to the long operation time and high temperature of the plug in the reactor, the traditional method of pasting coding points as detection points cannot be directly applied, and there are problems in measuring the thermal deformation of the plug. Summary of the Invention

[0004] The object of the present invention is to provide a method for measuring thermal deformation of a plug in a reactor, so as to solve the technical problem of inconvenience in measuring thermal deformation of the plug in the prior art.

[0005] In a first aspect, the present invention provides a method for measuring thermal deformation of a plug in a reactor, comprising the following steps:

[0006] Before the stack container is placed in place, a three-dimensional coordinate system is established based on at least three non-collinear and fixed first three-dimensional control points of the surrounding environment using a laser measurement device;

[0007] At least three measuring frames for mounting laser measuring equipment are fixedly arranged on the inner wall of the pile top protective cover;

[0008] After the pile top protective cover is installed, at least three reference targets are evenly fixed on the inner wall of the pile top protective cover, and initial observation values ​​of the reference targets are obtained based on a three-dimensional coordinate system using a laser measurement device;

[0009] Fix at least three detection targets on the stopcock;

[0010] When the pit is in a cold state, the laser measuring equipment is installed on each measuring frame in turn. With the reference target as the reference, the laser measuring equipment is used to measure the detection target to obtain the initial observation value of the detection target;

[0011] When the pile pit is in a heating state, the reference target is remeasured with the first three-dimensional control point as a reference to obtain the remeasured observation value of the reference target, and the reference target is calibrated based on the remeasured observation value and the initial observation value of the reference target; the laser measurement equipment is installed on each measurement frame in turn, and the detection target is remeasured with the calibrated reference target as a reference to obtain the remeasured observation value of the detection target, and the thermal deformation of the plug is calculated based on the remeasured observation value and the initial observation value of the detection target.

[0012] In an optional embodiment, the reference target is installed in an area 1.5 meters to 2 meters away from the bottom of the pile top protective cover.

[0013] In an optional embodiment, the initial observation value and the remeasured observation value of the reference target both include the three-dimensional coordinates of the reference target, and the initial observation value and the remeasured observation value of the detection target both include the three-dimensional coordinates of the detection target.

[0014] In an optional embodiment, the process of calibrating the reference target based on the remeasured observation value and the initial observation value of the reference target includes the following steps:

[0015] Calculate the difference between the re-measured observation value and the initial observation value of the reference target. If the difference is less than the preset difference threshold, no calibration is performed.

[0016] If the difference is greater than the preset difference threshold, the remeasured observation value is assigned to the initial observation value.

[0017] In an optional embodiment, the preset difference threshold is 0.3 mm.

[0018] In an optional embodiment, when the stack pit is in a state of increasing temperature, the detection target and the reference target are re-measured at each temperature section of the stack pit, the reference target is calibrated, and the thermal deformation of the plug is calculated.

[0019] In an optional embodiment, the indicators of thermal deformation of the plug include the coordinates of the center of the plug and the horizontality of the upper surface of the plug.

[0020] In an optional embodiment, a material changer is fixed on the plug, and the indicator of thermal deformation of the plug also includes the verticality of the material changer.

[0021] In an optional embodiment, the detection targets are uniformly clamped on the gear of the plug in the circumferential direction, and a detection target is set every 5°.

[0022] In an optional embodiment, the plugs in the reactor include a large plug, a middle plug, and a small plug, and thermal deformation measurement is performed on the large plug, the middle plug, and the small plug at the same time.

[0023] The present invention provides a method for measuring thermal deformation of a plug in a reactor, which has the following beneficial effects:

[0024] 1. The present invention adopts a detection target fixed on the plug as the detection object, which solves the problem that the traditional pasted coding point cannot withstand the high temperature generated by the plug during the operation of the nuclear reactor, and can continuously perform detection during the operation of the nuclear reactor.

[0025] 2. The present invention introduces a reference target as a detection reference for the detection target, and uses a first three-dimensional control point fixed in the external environment as the detection reference for the reference target. The heat generated during the operation of the nuclear reactor will cause the top protective cover to be thermally deformed, which in turn causes the position of the reference target to change. At the same time, due to the structural characteristics of the top reactor, it is impossible to use the first three-dimensional control point fixed in the external environment as the detection reference for the detection target. Therefore, re-testing the reference target with the first three-dimensional control point as the reference can timely detect the position change of the reference target and calibrate the reference target, thereby ensuring the accuracy of subsequent detection of the detection target with the reference target as the reference, and avoiding the detection result being affected by the thermal deformation of the top protective cover.

[0026] 3. The method of the present invention has a high degree of automation and high measurement efficiency. At the same time, it requires little modification to existing equipment, has low application cost and low measurement cost. Automatic data collection has little impact on the results, and can measure the entire object to be measured, fully understanding the deformation of the plug. The laser measurement equipment has high detection accuracy and can meet the requirements of thermal deformation measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic diagram of establishing a three-dimensional coordinate system in a method for measuring thermal deformation of a plug in a reactor provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of setting a laser measuring device and a reference target in a method for measuring thermal deformation of a plug in a reactor provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the relationship between a laser measuring device and a plug in a method for measuring thermal deformation of a plug in a reactor provided by an embodiment of the present invention;

[0031] Figure 4 A schematic diagram of a measuring frame of a laser measuring device in a method for measuring thermal deformation of a plug in a reactor provided by an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of a detection target fixed on a plug in a reactor plug thermal deformation measurement method provided by an embodiment of the present invention;

[0033] Figure 6 A schematic diagram of calculating the thermal deformation of a plug in a reactor plug thermal deformation measurement method provided by an embodiment of the present invention.

[0034] Icons: 100-UJA plant; 110-second three-dimensional control point; 200-inner wall of the pit; 210-first three-dimensional control point; 300-top protective cover; 410-large plug; 420-middle plug; 430-small plug; 440-gear; 510-reference target; 520-detection target; 600-measuring frame; 710-recharger flange; 720-recharger upper grabbing device. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0038] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0040] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0042] An embodiment of the present invention provides a method for measuring thermal deformation of a plug in a reactor, comprising the following steps:

[0043] Before the stack container is placed in place, a three-dimensional coordinate system is established based on at least three non-collinear and fixed first three-dimensional control points 210 of the surrounding environment using a laser measurement device;

[0044] At least three measuring frames 600 for mounting laser measuring equipment are fixedly installed on the inner wall of the stack top protective cover 300;

[0045] After the stack top protective cover 300 is installed, at least three reference targets 510 are evenly fixed on the inner wall of the stack top protective cover 300 , and initial observation values ​​of the reference targets 510 are obtained based on a three-dimensional coordinate system using a laser measurement device;

[0046] Fixing at least three detection targets 520 on the stopcock;

[0047] When the pile pit is in a cold state, the laser measuring equipment is sequentially installed on each measuring frame 600, and the reference target 510 is used as a reference to detect the detection target 520 using the laser measuring equipment to obtain the initial observation value of the detection target 520;

[0048] When the pile pit is in a heated state, the reference target 510 is remeasured with the first three-dimensional control point 210 as a reference to obtain the remeasured observation value of the reference target 510, and the reference target 510 is calibrated based on the remeasured observation value and the initial observation value of the reference target 510; the laser measurement equipment is installed on each measurement frame 600 in turn, and the detection target 520 is remeasured with the calibrated reference target 510 as a reference to obtain the remeasured observation value of the detection target 520, and the thermal deformation of the plug is calculated based on the remeasured observation value and the initial observation value of the detection target 520.

[0049] This embodiment uses a detection target 520 fixed on the plug as the detection object, which solves the problem that traditional adhesive coding points cannot withstand the high temperature generated on the plug during the operation of the nuclear reactor, and can continuously perform detection during the operation of the nuclear reactor.

[0050] This embodiment introduces a reference target 510 as a detection reference for the detection target 520, and uses a first three-dimensional control point 210 fixed in the external environment as a detection reference for the reference target 510. The heat generated during the operation of the nuclear reactor will cause the top protective cover 300 to be thermally deformed, which in turn causes the position of the reference target 510 to change. At the same time, due to the structural characteristics of the top reactor, it is impossible to use the first three-dimensional control point 210 fixed in the external environment as a detection reference for the detection target 520. Therefore, re-testing the reference target 510 with the first three-dimensional control point 210 as a reference can timely detect the position change of the reference target 510 and calibrate the reference target 510, thereby ensuring the accuracy of subsequent detection of the detection target 520 with the reference target 510 as a reference, and avoiding the detection results being affected by the thermal deformation of the top protective cover 300.

[0051] The method of this embodiment has a high degree of automation and high measurement efficiency. At the same time, it requires little modification to existing equipment, has low application cost, and low measurement cost. Automatic data collection has little impact on the results, and the entire object being measured can be measured to fully understand the deformation of the plug. The laser measurement equipment has high detection accuracy and can meet the requirements of thermal deformation measurement.

[0052] Figure 1 A schematic diagram of establishing a three-dimensional coordinate system in a method for measuring thermal deformation of a plug in a reactor provided by an embodiment of the present invention, such as Figure 1 As shown, before the stack container is put into place, a three-dimensional coordinate system is established based on at least three fixed first three-dimensional control points 210 of the surrounding environment using a laser measurement device.

[0053] Specifically, in this embodiment, Figure 1As shown, the first three-dimensional control points 210 are specifically three-dimensional control points at the 200+17.0m layer of the inner wall of the pile pit, and there are five of them. At the same time, five second three-dimensional control points 110 are arranged on the wall of the 100+20.0m layer of the UJA plant. Due to the special shape of the inner wall 200 of the pile pit, Figure 1 There are two first three-dimensional control points 210 on the upper inner wall and the lower inner wall of Figure 1 The left inner wall of the image is provided with a first three-dimensional control point 210. The second three-dimensional control points 110 are roughly evenly distributed at 90 degrees. Figure 1 A second three-dimensional control point 110 is set at the top, bottom and left of Figure 1 Two relatively close second three-dimensional control points 110 are set on the right side of FIG.

[0054] After setting up the laser detection equipment, the first three-dimensional control point 210 is used as a reference for the measurement. After the measurement is completed, the laser detection equipment is changed to check the relative relationship between the first three-dimensional control point 210 and the second three-dimensional control point 110. After the verification is qualified, the three-dimensional coordinate system is established.

[0055] Specifically, the laser detection device may be a laser tracker, which can realize large-space and ultra-high-precision detection, and is especially used for thermal deformation measurement of nuclear reactor plugs.

[0056] In other embodiments, the positions and quantities of the first three-dimensional control point 210 and the second three-dimensional control point 110 may also be in other forms and are not limited to the specific settings of the positions and quantities in this embodiment.

[0057] In this embodiment, the measuring frame 600 is as follows Figure 4 As shown, the measuring frame 600 includes mounting holes for fixing the laser detection equipment, and the measuring frame 600 is fixed to the inner wall of the stack top protective cover 300 by welding. Figure 2 to ensure a secure installation. Figure 2 The first three-dimensional control point 210 is omitted in the figure, but it still exists in actual application.

[0058] In other embodiments, the number of measuring frames 600 is not limited to four, and may be other numbers, which is not limited in this application.

[0059] In this embodiment, if Figure 2 As shown, eight reference targets 510 are fixed roughly evenly in the anti-deformation area of ​​the inner wall of the stack top protective cover 300 . The positions of the reference targets 510 should be able to be detected by the laser measuring equipment on the measuring frame 600 .

[0060] In other embodiments, the specific number of reference targets 510 may be other forms and is not limited to 8.

[0061] In this embodiment, the reference target 510 is installed 1.5 to 2 meters from the bottom of the reactor top shield 300. This area has been calculated to ensure it will not affect the normal operation of the stopcock. The reference target 510 can be secured to the reactor top shield 300 by bonding. During nuclear reactor operation, the temperature of the reactor top shield 300 generally does not exceed 50 degrees Celsius, which does not affect the bonding effect.

[0062] After the reference target 510 is fixed, the laser detection equipment is first connected to the four measurement frames 600 in sequence, and the reference targets 510 are respectively detected to verify the position of the reference targets 510 .

[0063] Tables 1.1 through 1.4 show the results of four tests, each of which tests the accuracy of reference targets 510 on four measurement stands 600. The laser measurement equipment cannot simultaneously measure all reference targets 510 on each measurement stand 600. In Tables 1.1 through 1.4, the eight reference targets 510 are represented by point numbers (top 1# through top 8#).

[0064] Table 1.1 Benchmark target 510 accuracy test results 1

[0065]

[0066] Table 1.2 Benchmark target 510 accuracy test results 2

[0067]

[0068] Table 1.3 Benchmark target 510 accuracy test results 3

[0069]

[0070] Table 1.4 Benchmark target 510 accuracy test results 4

[0071]

[0072] As shown in Tables 1.1 to 1.4, the deviations of all reference targets 510 in all test results are less than 0.3 mm, meeting the accuracy requirements.

[0073] In this embodiment, when obtaining the initial observation value of the detection target 520 in the cold state, the cock is reset to zero position in advance to ensure the consistency of the cock state in subsequent tests, thereby keeping the theoretical position of the detection target 520 consistent.

[0074] In this embodiment, two consecutive tests are performed in the cold state. When the difference between the initial observation values ​​of the two tests is less than or equal to 0.3 mm, the average of the two tests is taken as the initial observation value. If the difference between the initial observation values ​​of the two tests is greater than 0.3 mm, retesting is required to ensure the accuracy of the initial test and avoid misjudgment in subsequent tests.

[0075] In this embodiment, the initial observation value and the remeasured observation value of the reference target 510 both include the three-dimensional coordinates of the reference target 510, and the initial observation value and the remeasured observation value of the test target 520 both include the three-dimensional coordinates of the test target 520. Specifically, the reference target 510 and the test target 520 can be measured using SA software in conjunction with a laser tracker, and the detection results can be solved using a built-in algorithm in the SA software, such as the least squares method, to obtain the three-dimensional coordinates of the reference target 510 and the test target 520.

[0076] In this embodiment, the process of calibrating the reference target 510 based on the re-measured observation value and the initial observation value of the reference target 510 includes the following steps: calculating the difference between the re-measured observation value and the initial observation value of the reference target 510; if the difference is less than a preset difference threshold, no calibration is performed; if the difference is greater than the preset difference threshold, the re-measured observation value is assigned to the initial observation value. The preset difference threshold is 0.3 mm. When the difference is less than the preset difference threshold, it can be considered that it is only a detection error. When the difference is greater than the predicted difference threshold, it can be considered that the deformation of the stack top protective cover 300 has affected the position of the reference target 510, and the position of the reference target 510 has changed. In this case, the re-measured observation value should be copied to the initial observation value, thus completing the calibration of the reference target 510.

[0077] When re-measuring the reference target 510, a suitable position is selected so that the laser measurement equipment can simultaneously observe the first three-dimensional control point 210 and the reference target 510, thereby re-measuring the reference target 510 using the first three-dimensional control point 210 as the reference. Because the stack top protective cover 300 needs to exchange materials with the outside, it has gaps and other structures in its structure. These gaps can be used to re-measuring the reference target 510. However, due to the position of the stopcock, there is no position on the stack top protective cover 300 where both the first three-dimensional control point 210 and the detection target 520 on the stopcock can be simultaneously observed. Therefore, the detection target 520 cannot be inspected using the first three-dimensional control point 210 as the reference.

[0078] In this embodiment, the detection targets 520 are evenly fixed on the gear 440 of the plug in the circumferential direction, and a detection target 520 is set every 5 degrees. Figure 5 As shown, Figure 5 4 is a partial schematic diagram of the gear 440 of the cock. Thus, a total of 72 detection targets 520 are provided on the cock, which can more accurately detect the thermal deformation of the cock.

[0079] In other embodiments, detection targets 520 may be arranged on the stopcock at other intervals. The more detection targets 520 there are, the more accurate the detection results. Furthermore, since the detection targets 520 are detected using a laser measurement device, the laser measurement device can quickly complete the detection of multiple detection targets 520. Therefore, adding more detection targets 520 does not significantly reduce the detection efficiency of the detection targets 520.

[0080] In this embodiment, when the pit is in a state of increasing temperature, the detection target 520 and the reference target 510 are re-measured at each temperature section of the pit, the laser measurement equipment is self-calibrated, and the thermal deformation of the plug is calculated.

[0081] In this embodiment, the plugs in the reactor include a large plug 410, a medium plug 420, and a small plug 430. Thermal deformation measurements are performed on the large plug 410, the medium plug 420, and the small plug 430. A refueling machine is fixed on the small plug 430. Figure 3 The thermal deformation indicators of the plug include the center coordinates and upper surface level of each plug, as well as the verticality of the material changer. The schematic diagram for calculating the thermal deformation of the plug is shown in Figure 6 shown.

[0082] The results of retesting the reference target 510 under the elevated temperature are shown in Table 1.5. Table 1.5 shows the retest results of the reference target 510. The difference is greater than 3 mm, indicating that the top protective cover 300 has been deformed due to the heat dissipation during the operation of the nuclear reactor. At this time, the retested observation value needs to be assigned to the initial observation value, that is, the retested observation value is used as the benchmark.

[0083] Table 1.5 Results of retest of reference target 510

[0084]

[0085] The main reason for thermal deformation of the stack top protective cover 300 is that the metal strength of the stack top protective cover 300 decreases and softens due to temperature. Furthermore, deformation occurs due to the heavy weight of the stack top protective cover 300, which can exceed 80 tons. This causes the transfer station reference point to sink, resulting in a decrease in the z-axis value in Table 1.5. However, deformation in the planar position is very small.

[0086] After testing the large stopcock 410, the medium stopcock 420, and the small stopcock 430, the initial test and retest results of the center coordinates of each stopcock are shown in Table 1.6.

[0087] Table 1.6 Fitting center results of large plug 410, medium plug 420 and small plug 430

[0088]

[0089] When calculating the levelness of the tap, if Figure 6 As shown, the unit vector of the circumference normal of the plug is fitted using SA software for calculation. If the unit vector is (dx, dy, dz), the angle α between the upper surface of the plug and the horizontal plane has the following relationship: tanα= , then the horizontality of the upper surface is: △H= tanα*2R, where R is the radius of the plug. The horizontality of each plug is calculated in turn, and the test results are shown in Table 1.7.

[0090] Table 1.7 Levelness results of large plug 410, medium plug 420 and small plug 430

[0091]

[0092] The horizontality of the cock will eventually affect the verticality of the material changer, such as Figure 6 As shown, the verticality of the refueling machine is calculated based on the center coordinates (X1, Y1, Z1) of the refueling machine flange 710 and the center coordinates (X2, Y2, Z2) of the refueling machine upper gripping device 720. The change in the verticality of the refueling machine caused by thermal deformation is detected. The calculation formula is as follows: , where D is the verticality of the refueling machine. The refueling machine flange 710 is fixed to the small plug 430. The center coordinates of the refueling machine flange 710 and the small plug 430 have a fixed conversion relationship, which is subject to the actual installation. The results of the refueling machine verticality test are shown in Table 1.8.

[0093] Table 1.8 Verticality test results of the refueling machine

[0094]

[0095] The verticality of the refueling machine affects whether refueling can proceed normally. The guide tubes in the refueling machine have a certain adjustment range for verticality. If the verticality exceeds this adjustment range, refueling cannot proceed normally and an error is required. As shown in Table 1.8, the maximum verticality of the refueling machine is 2.88 mm / m, while the guide tubes in the refueling machine require a verticality of 3 mm / m. This is within the adjustment range of the guide tubes.

[0096] The specific form of the detection target 520 and the reference target 510 can be a target ball. When being fixed, they can also be fixed to the pile top protective cover or gear through a target base, and then the target ball is fixed on the target base.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring thermal deformation of a plug in a reactor, characterized in that: The following steps are involved: Before the stack container is placed in place, a three-dimensional coordinate system is established based on at least three non-collinear and fixed first three-dimensional control points (210) of the surrounding environment using a laser measurement device; At least three measuring frames (600) for mounting laser measuring equipment are fixedly arranged on the inner wall of the stack top protective cover (300); After the stack top protective cover (300) is installed, at least three reference targets (510) are evenly fixed on the inner wall of the stack top protective cover (300), and initial observation values ​​of the reference targets (510) are obtained based on a three-dimensional coordinate system using a laser measurement device; fixing at least three detection targets (520) on the stopcock; When the pile pit is in a cold state, the laser measuring equipment is sequentially installed on each measuring frame (600), and the detection target (520) is detected using the laser measuring equipment with the reference target (510) as a reference, to obtain an initial observation value of the detection target (520); When the pile pit is in a heated state, the reference target (510) is re-measured with the first three-dimensional control point (210) as a reference, and the re-measured observation value of the reference target (510) is obtained. The reference target (510) is calibrated based on the re-measured observation value and the initial observation value of the reference target (510); the laser measuring equipment is sequentially installed on each measuring frame (600), and the detection target (520) is re-measured with the calibrated reference target (510) as a reference, and the re-measured observation value of the detection target (520) is obtained. The thermal deformation of the plug is calculated based on the re-measured observation value and the initial observation value of the detection target (520).

2. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The reference target (510) is installed in an area 1.5 to 2 meters away from the bottom of the stack top protective cover (300).

3. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The initial observation value and the re-measured observation value of the reference target (510) both include the three-dimensional coordinates of the reference target (510), and the initial observation value and the re-measured observation value of the detection target (520) both include the three-dimensional coordinates of the detection target (520).

4. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The process of calibrating the reference target (510) based on the remeasured observation value and the initial observation value of the reference target (510) includes the following steps: Calculating the difference between the re-measured observation value and the initial observation value of the reference target (510), and if the difference is less than a preset difference threshold, no calibration is performed; If the difference is greater than the preset difference threshold, the remeasured observation value is assigned to the initial observation value.

5. The method for measuring thermal deformation of a plug in a reactor according to claim 4, characterized in that: The preset difference threshold is 0.3 mm.

6. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: When the pit is in a state of temperature increase, the detection target (520) and the reference target (510) are retested at each temperature section of the pit, the reference target (510) is calibrated, and the thermal deformation of the plug is calculated.

7. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The indicators of thermal deformation of the plug include the coordinates of the plug center and the horizontality of the upper surface of the plug.

8. The method for measuring thermal deformation of a plug in a reactor according to claim 7, characterized in that: A material changer is fixed on the cock, and the thermal deformation index of the cock also includes the verticality of the material changer.

9. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The detection targets (520) are evenly clamped on the gear (440) of the plug in the circumferential direction, with one detection target (520) being arranged every 5°.

10. The method for measuring thermal deformation of a plug in a reactor according to claim 1, characterized in that: The plugs in the reactor include a large plug (410), a medium plug (420), and a small plug (430), and thermal deformation measurement is performed on the large plug (410), the medium plug (420), and the small plug (430) at the same time.

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