Device for improving semi-automatic eddy current detection stability of heat transfer tube with tube-plate structure and use method

Abstract

The invention relates to a device for improving the semi-automatic eddy current detection stability of a heat transfer tube with a tube plate structure and a use method. The device comprises a handheld gun head driver, an eddy current flaw detector probe, a positioning assist device and a plane position fixing wheel, the positioning assistor, the eddy current flaw detector probe and the plane position fixing wheel are all installed at the output end of the handheld gun head driver, the positioning assistor is used for achieving centering of the eddy current flaw detector probe after being inserted into a pipe hole, and the plane position fixing wheel is used for limiting the positioning assistor to be arranged in the pipe hole to keep the preset depth. When the semi-automatic eddy current detection device is used for carrying out semi-automatic eddy current detection on a heat transfer tube, a detector can realize rapid positioning of a to-be-detected tube hole through the positioning assistor and the plane fixing wheel which are additionally arranged at the position of the gun head, and meanwhile, the positioning assistor and the plane fixing wheel can relieve the load on the arm caused by holding the gun head driver by hand for a long time by the detector; the detection stability is greatly improved, and the detection efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of thermal power equipment detection technology, and in particular to a device and a method for using the device for improving the stability of semi-automatic eddy current detection of heat transfer tubes in tube sheet structures such as condensers and high-pressure heaters. Background Art

[0002] The investment cost of tube sheet heat transfer equipment such as condensers, high-pressure heaters, and low-pressure heaters is high, the structure is complex, and the working environment is harsh. Tube bundle leakage has always been an unresolved problem in the thermal power generation construction industry. With the continuous increase in boiler temperature and pressure parameters, the challenges faced by the prevention of tube bundle leakage of heat transfer tubes in tube sheet structure equipment are becoming increasingly greater. Tube bundle corrosion and leakage will cause condensate deterioration, vacuum decrease, and coal consumption increase, which will directly affect the safe and economic operation of the unit and cause great harm to equipment such as boilers and steam turbines. A single leakage inspection will result in a loss of millions or even tens of millions of power generation, coupled with the loss of steam and water and labor and material losses, which has a huge impact on the power plant. Therefore, all power generation groups have taken the control of condenser tube leakage as a key task of "curbing non-compliance".

[0003] At present, the main detection method for shell-and-tube heat exchangers is manual eddy current detection, which is time-consuming, labor-intensive and inefficient. Taking a 1000MW unit as an example, each steam turbine is equipped with two condensers, with a total of more than 50,000 tubes, each about 15 meters long. The total length of a push-pull probe for 100% manual eddy current detection of a condenser tube is about 1,500 kilometers, and it needs to be pushed and pulled at a constant speed, which requires great physical strength from the detection personnel. A single instrument often requires 3-4 personnel to take turns to push and retract the probe, and the detection efficiency is low. At the same time, the reliability of the detection results is poor, and there are phenomena such as missed detection and misjudgment, which seriously affect the safe and economical operation of thermal power units.

[0004] In order to solve a series of problems existing in the prior art, the prior art discloses a tube sheet semi-automatic eddy current inspection scanning system, which realizes the eddy current semi-automatic inspection of the tube bundle of the tube sheet heat transfer equipment by handheld semi-automatic method, reduces labor intensity and improves inspection efficiency. However, this structure also has a series of problems, such as the heavy weight of the gun head itself, the large transmission power of the eddy current pusher, which makes it impossible for the inspector to hold the gun head for a long time, the difficulty in aligning the eddy current probe with the tube sheet, the poor inspection stability, and it is difficult for semi-automatic inspection to significantly improve the inspection efficiency. Summary of the invention

[0005] In order to solve the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a device and a method for using the device to improve the stability of semi-automatic eddy current detection of heat transfer tubes with tube sheet structure. The efficiency and stability of eddy current detection can be further improved. While improving the stability of eddy current semi-automatic detection, the method can realize the automatic centering of eddy current probe and tube bundle, eliminating the need for personnel to perform the centering process of eddy current probe and tube bundle by visual method, thus shortening the detection time.

[0006] The technical means adopted by the present invention are as follows:

[0007] A device for improving the stability of semi-automatic eddy current detection of heat transfer tubes with a tube sheet structure, comprising a handheld gun head actuator, an eddy current flaw detector probe, a positioning aid and a plane position fixing wheel, wherein the positioning aid, the eddy current flaw detector probe and the plane position fixing wheel are all installed at the output end of the handheld gun head actuator, the positioning aid is used to realize the centering of the eddy current flaw detector probe after being inserted into the tube hole, and the plane position fixing wheel is used to limit the positioning aid to be placed in the tube hole to maintain a preset depth.

[0008] Furthermore, a groove below the surface is processed at the front end of the gun head shell of the handheld gun head actuator, and a clamp is installed on it, through which the eddy current flaw detector probe, positioning aid and plane position fixing wheel are installed.

[0009] Furthermore, the positioning aid includes two positioning legs of the same length arranged in parallel, the clamp is a three-petal structure, the clamp is fastened to the groove of the gun head transmission housing by a locking bolt, the clamp locks the left and right sides by locking bolts to simultaneously fix the two positioning leg brackets, and the positioning legs are installed on the positioning leg brackets.

[0010] Furthermore, the plane position fixing wheel comprises a rubber wheel, a bearing, a wheel seat and an extension rod, the rubber wheel is mounted on the wheel seat via the bearing, and the wheel seat is mounted on the clamp via the extension rod.

[0011] Furthermore, the plane position fixing wheel and the positioning assistant are connected to the clamp through threads, and a nut is provided on the clamp. By adjusting the position of the nut on the clamp, the length of the plane position fixing wheel and the positioning assistant is adjusted.

[0012] Furthermore, the difference between the extension distance of the two positioning assistants and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet.

[0013] Furthermore, the positioning leg is a conical petal structure, and its maximum diameter is 95% of the inner diameter of the tube bundle to be inspected.

[0014] The present invention also discloses a method for using the above device, including:

[0015] S1. Use eddy current detection handheld gun head actuator;

[0016] S2. Use a three-petal structure clamp, and the position of the petals of the clamp should be in a triangular correspondence with the tube holes of the heat exchanger;

[0017] S3. According to the width of the clamp, a groove is machined at 1 / 3 of the distance from the gun head. The width of the groove is equivalent to the width of the clamp, so that the clamp and the groove can be closely matched.

[0018] S4. Fix the clamp to the groove of the gun head through the locking bolt;

[0019] S5. Select the positioning legs and connect them to the clamp ears through threads and nuts on both sides;

[0020] S6. Use a plane position fixed wheel, one end of which is connected to the clamp ear through a thread and nuts on both sides;

[0021] S7. Adjust the extension distance of the two positioning legs and the plane position fixing wheel through the threads and nuts. The difference between the extension distance of the two positioning legs and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet. Tighten the positioning legs and the plane position fixing wheel nuts to fix the corresponding positions.

[0022] S8. Hold the gun head actuator and insert the two positioning legs into the tube hole used for positioning. When the flat wheel is against the tube sheet surface, the size of the positioning legs extending into the tube hole does not exceed 2 / 3 of the tube sheet thickness. At the same time, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be detected. When the handheld gun head actuator applies a vertical force to the tube sheet plane, the positioning aid does not have obvious axial movement, and the method is debugged.

[0023] Furthermore, after S8, the following steps are also included:

[0024] S9. When carrying out semi-automatic eddy current testing on heat transfer tubes of tube sheet structure equipment, after the testing personnel complete the debugging, turn on the power of eddy current detector and pusher, insert the two positioning legs into the tube hole used for positioning, the flat wheel is against the tube sheet surface, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be tested, turn on the handheld gun head transmission handle switch, the pusher is running, and the eddy current probe is sent into the tube hole to be tested through the center of the gun barrel. At the same time, the eddy current detector collects and records the eddy current detection signal. When the size of the eddy current probe inserted into the tube hole is ≥ the tube bundle length, the eddy current semi-automatic detection of the tube hole and tube bundle is completed.

[0025] Compared with the prior art, the present invention has the following advantages: the present invention discloses a device and a method for using the device for improving the stability of semi-automatic eddy current detection of heat transfer tubes with a tube sheet structure. When carrying out semi-automatic eddy current detection of heat transfer tubes, the detection personnel can use the positioning assistant and the flat fixing wheel installed at the gun head position. According to the method of using the present invention, the rapid positioning of the tube hole to be detected can be achieved. At the same time, the positioning assistant and the flat fixing wheel can reduce the load on the arm caused by the personnel holding the gun head transmission for a long time, and the detection stability is greatly improved, and the detection efficiency is greatly improved.

[0026] Compared with the prior art, the present invention provides a device and a method for using the semi-automatic eddy current detection of heat transfer tubes with a tube sheet structure. By adding a positioning aid and a plane fixing wheel to the transmission device, the eddy current probe at the center of the gun head can quickly and accurately locate the center of the tube hole, which is more accurate than the centering by human eyes in the prior art, and avoids the eddy current probe from colliding with the tube sheet and damaging the probe. At the same time, by adjusting the difference between the extension distance of the two positioning legs and the position of the plane position fixing wheel to 2 / 3 of the thickness of the heat exchanger tube sheet, it can be avoided that the positioning legs extend too far into the tube hole and damage the tube bundle due to angle deviation. The present invention solves a series of problems existing in the prior art, such as the heavy weight of the gun head itself, the large transmission power of the eddy current pusher, the inability of the inspector to hold the gun head for a long time, the difficulty in centering the eddy current probe with the tube sheet, the poor detection stability, and the difficulty in significantly improving the detection efficiency of the semi-automatic detection. It is simple and convenient to use, and one adjustment can be applied to the semi-automatic detection of heat exchanger tubes with different rated capacities. The stability of the detection system can be greatly improved, and the labor intensity of the inspector is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

[0028] Figure 1 A top view of the device of the present invention;

[0029] Figure 2 A schematic diagram of detection and use of an embodiment of the present invention;

[0030] In the figure: 1-handheld gun head actuator; 2-positioning leg; 3-plane position fixing wheel; 4-clamp; 5-gun head; 21-tube bundle to be tested; 22-device of the present invention. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in 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. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0035] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0036] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0037] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0038] like Figure 1 , Figure 2 As shown, the embodiment of the present invention discloses a device 22 for improving the stability of semi-automatic eddy current detection of heat transfer tubes with tube sheet structure, comprising a handheld gun head actuator 1, an eddy current flaw detector probe, a positioning aid and a plane position fixing wheel 3, wherein the positioning aid, the eddy current flaw detector probe and the plane position fixing wheel are all installed at the output end of the handheld gun head actuator, the positioning aid is used to realize the centering of the eddy current flaw detector probe after being inserted into the tube hole, and the plane position fixing wheel is used to limit the positioning aid to be placed in the tube hole to maintain a preset depth. The eddy current flaw detector probe is set in the gun head 5, and after positioning, during detection, the eddy current probe extends from the center of the gun head.

[0039] The handheld gun tip actuator used in the present invention is used to guide the eddy current probe (eddy current flaw detector probe) to detect the heat exchanger tube. To facilitate the installation of the positioning aid, a groove below the surface is processed at the front end gun tip shell of the handheld gun tip actuator, and a clamp 4 is installed on it. The installation of the eddy current flaw detector probe, the positioning aid and the plane position fixing wheel is completed through the clamp. In this embodiment, the processing size of the groove at the gun tip actuator shell is equivalent to the size of the clamp, which can form a close fit between the clamp and the groove. When the clamp and the gun tip groove are completely tightened, no movement or loosening occurs when an external force of less than or equal to 500N is applied along the axial direction of the gun tip.

[0040] The positioning aid includes two positioning legs 2 of the same length arranged in parallel, the clamp is a three-petal structure, the clamp is fastened to the groove of the gun head transmission housing by a locking bolt, the clamp is locked on both sides to simultaneously fix the two positioning leg brackets by locking bolts, and the positioning legs are installed on the positioning leg brackets. In this embodiment, the positions of the two positioning legs and the eddy current probe at the center of the gun head correspond one to one with the size positions of the three tube holes of the two adjacent layers of the tube sheet heat transfer tube.

[0041] The plane position fixing wheel comprises a rubber wheel, a bearing, a wheel seat and an extension rod, wherein the rubber wheel is mounted on the wheel seat through the bearing, and the wheel seat is mounted on the clamp through the extension rod. Specifically, the wheel seat is locked with the clamp through the axial extension rod of the gun head through bolts.

[0042] The plane position fixing wheel and the positioning assistant are connected to the clamp through threads, and a nut is provided on the clamp. By adjusting the position of the nut on the clamp, the length of the plane position fixing wheel and the positioning assistant is adjusted, and the extension distance is adjusted through the threads and the nut.

[0043] The difference between the extension distance of the two positioning assistants and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet.

[0044] The positioning leg is a conical petal structure, made of brass, and has a maximum diameter of 95% of the inner diameter of the tube bundle to be tested. The other end of the positioning leg is processed with a 20mm long thread, and the other end of the positioning leg is connected to the clamp through a nut.

[0045] The invention also discloses a method for using the device.

[0046] In this embodiment, the eddy current detection instrument uses the SMART-5001 multi-frequency array eddy current detector produced by Edson (Xiamen) Electronics Co., Ltd., uses a shear wave phased array probe, the frequency range is 10HZ~10MHz, the probe uses an array internal eddy current probe, and the length of the probe and the signal line matches the tube bundle to be tested. The object to be tested is a heat exchanger 21 with a tube sheet structure, with a tube diameter specification of φ22×0.7mm, a tube sheet thickness of 25mm, and a tube bundle length of 12 meters.

[0047] The specific steps include:

[0048] S1. Use eddy current detection handheld gun head actuator; the thickness of the actuator barrel is 8mm;

[0049] S2. Use a three-petal structure clamp, and the position of the petals of the clamp should be in a triangular correspondence with the tube holes of the heat exchanger;

[0050] S3. According to the width of the clamp, a groove is machined at 1 / 3 of the distance from the gun head. The width of the groove is equivalent to the width of the clamp, so that the clamp and the groove can be closely matched.

[0051] S4. Fix the clamp to the groove of the gun head through the locking bolt;

[0052] S5. Select the positioning legs and connect them to the clamp ears through threads and nuts on both sides;

[0053] S6. Use a plane position fixed wheel, one end of which is connected to the clamp ear through a thread and nuts on both sides;

[0054] S7. Adjust the extension distance of the two positioning legs and the plane position fixing wheel through the thread and nut. The difference between the extension distance of the two positioning legs and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet. Lock the positioning legs and the plane position fixing wheel nuts to fix the corresponding position. In this embodiment, the difference is 16 mm. Lock the positioning legs and the plane position fixing wheel nuts to fix the corresponding position.

[0055] S8. Hold the gun head actuator and insert the two positioning legs into the tube hole for positioning. When the plane wheel is on the tube sheet surface, the size of the positioning legs extending into the tube hole does not exceed 2 / 3 of the tube sheet thickness, i.e. 16mm. At the same time, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be detected. When the gun head actuator is held and applies a vertical force to the tube sheet plane, the positioning aid does not have obvious axial movement. The method is debugged. In the figure, the 6 round holes in 2 rows are the holes to be detected. The positioning legs and the gun head are on a horizontal line and are on the next layer of the holes to be detected relative to the plane wheel.

[0056] Furthermore, after S8, the following steps are also included:

[0057] S9. When carrying out semi-automatic eddy current testing on heat transfer tubes of tube sheet structure equipment, after the testing personnel complete the debugging, turn on the power of eddy current detector and pusher, insert the two positioning legs into the tube hole used for positioning, the flat wheel is against the tube sheet surface, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be tested, turn on the handheld gun head transmission handle switch, the pusher is running, and the eddy current probe is sent into the tube hole to be tested through the center of the gun barrel. At the same time, the eddy current detector collects and records the eddy current detection signal. When the size of the eddy current probe inserted into the tube hole is ≥ the tube bundle length, the eddy current semi-automatic detection of the tube hole and tube bundle is completed.

[0058] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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 device for improving the stability of semi-automatic eddy current detection of heat transfer tubes with tube sheet structure, characterized in that: The invention comprises a hand-held gun tip transmission device, an eddy current flaw detector probe, a positioning aid and a plane position fixing wheel. The positioning aid, the eddy current flaw detector probe and the plane position fixing wheel are all installed at the output end of the hand-held gun tip transmission device. The positioning aid is used to realize the centering of the eddy current flaw detector probe after being inserted into the pipe hole. The plane position fixing wheel is used to limit the positioning aid to be placed in the pipe hole to maintain a preset depth.

2. The device for improving the stability of semi-automatic eddy current detection of heat transfer tubes with tube sheet structure according to claim 1, characterized in that: A groove lower than the surface is processed at the front end of the gun head shell of the handheld gun head actuator, and a clamp is installed on it. The installation of the eddy current flaw detector probe, the positioning aid and the plane position fixing wheel is completed through the clamp.

3. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to claim 2, characterized in that: The positioning aid includes two positioning legs of the same length arranged in parallel. The clamp is a three-petal structure. The clamp is fastened to the groove of the gun head transmission housing by a locking bolt. The clamp locks the left and right sides by locking bolts to simultaneously fix the two positioning leg brackets, and the positioning legs are installed on the positioning leg brackets.

4. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to claim 2, characterized in that: The plane position fixing wheel comprises a rubber wheel, a bearing, a wheel seat and an extension rod. The rubber wheel is installed on the wheel seat through the bearing, and the wheel seat is installed on the clamp through the extension rod.

5. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to claim 2, characterized in that: The plane position fixing wheel and the positioning assistant are connected to the clamp through threads, and a nut is arranged on the clamp. By adjusting the position of the nut on the clamp, the length of the plane position fixing wheel and the positioning assistant is adjusted.

6. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to claim 1, characterized in that: The difference between the extension distance of the two positioning assistants and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet.

7. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to claim 3, characterized in that: The positioning leg is a conical petal structure, and its maximum diameter is 95% of the inner diameter of the tube bundle to be inspected.

8. A method for using the device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with tube sheet structure according to any one of claims 1 to 7, characterized in that: The steps include: S1. Use eddy current detection handheld gun head actuator; S2. Use a three-petal structure clamp, and the position of the petals of the clamp should be in a triangular correspondence with the tube holes of the heat exchanger; S3. According to the width of the clamp, a groove is machined at 1 / 3 of the distance from the gun head. The width of the groove is equivalent to the width of the clamp, so that the clamp and the groove can be closely matched. S4. Fix the clamp to the groove of the gun head through the locking bolt; S5. Select the positioning legs and connect them to the clamp ears through threads and nuts on both sides; S6. Use a plane position fixed wheel, one end of which is connected to the clamp ear through a thread and nuts on both sides; S7. Adjust the extension distance of the two positioning legs and the plane position fixing wheel through the threads and nuts. The difference between the extension distance of the two positioning legs and the position of the plane position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet. Tighten the positioning legs and the plane position fixing wheel nuts to fix the corresponding positions. S8. Hold the gun head actuator and insert the two positioning legs into the tube hole used for positioning. When the flat wheel is against the tube sheet surface, the size of the positioning legs extending into the tube hole does not exceed 2 / 3 of the tube sheet thickness. At the same time, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be detected. When the handheld gun head actuator applies a vertical force to the tube sheet plane, the positioning aid does not have obvious axial movement, and the method is debugged.

9. The method according to claim 8, characterized in that After S8, there are also the following steps: S9. When carrying out semi-automatic eddy current testing on heat transfer tubes of tube sheet structure equipment, after the testing personnel complete the debugging, turn on the power of eddy current detector and pusher, insert the two positioning legs into the tube hole used for positioning, the flat wheel is against the tube sheet surface, the eddy current detection probe at the center of the gun head is aligned with the center of the tube hole to be tested, turn on the handheld gun head transmission handle switch, the pusher is running, and the eddy current probe is sent into the tube hole to be tested through the center of the gun barrel. At the same time, the eddy current detector collects and records the eddy current detection signal. When the size of the eddy current probe inserted into the tube hole is ≥ the tube bundle length, the eddy current semi-automatic detection of the tube hole and tube bundle is completed.

Images