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

Abstract

The utility model relates to a device for improving the semi-automatic eddy current detection stability of a heat transfer tube with a tube plate structure, which comprises a handheld gun head driver, an eddy current flaw detector probe, a positioning assistor 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 quick positioning of a tube hole to be detected through the positioning assistor and the plane fixing wheel which are additionally arranged at the gun head; and meanwhile, the positioning assistor and the plane fixing wheel can reduce the load on the arm caused by holding the gun head driver for a long time, so that the detection stability is greatly improved, and the detection efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal power equipment detection, in particular to a 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] Tube-sheet heat transfer equipment, such as condensers, high-pressure heaters, and low-pressure heaters, is subject to high investment costs, complex structures, and harsh operating environments. Tube bundle leakage has long been an unresolved issue in the thermal power generation industry. As boiler temperatures and pressures continue to rise, preventing leaks in the heat transfer tube bundles of tube-sheet equipment becomes increasingly challenging. Tube bundle corrosion and leakage can lead to condensate deterioration, reduced vacuum levels, and increased coal consumption, directly impacting the safe and economical operation of the unit and significantly harming equipment such as boilers and turbines. A single leak repair can result in millions or even tens of millions in lost power generation, combined with the loss of steam, water, labor, and materials, significantly impacting the power plant. Consequently, all power generation groups have prioritized the management of condenser tube leakage as a key priority.

[0003] Currently, the primary method for inspecting shell-and-tube heat exchangers is manual eddy current testing, which is time-consuming, labor-intensive, and inefficient. For example, a 1000MW unit has two condensers per turbine, totaling over 50,000 tubes, each approximately 15 meters long. A single condenser tube for 100% manual eddy current testing requires approximately 1,500 kilometers of push-and-pull probes, which must be pushed and pulled at a constant speed. This places significant physical demands on the inspectors, and a single instrument often requires three to four personnel to rotate the probes in and out, resulting in low inspection efficiency. Furthermore, the reliability of the test results is poor, with missed detections and misjudgments occurring frequently, seriously impacting the safe and economical operation of thermal power units.

[0004] To address a number of issues with existing technologies, a semi-automatic eddy current inspection system for tubesheets has been developed. This system, through a handheld, semi-automatic method, enables eddy current inspection of tube bundles in heat transfer equipment, reducing labor intensity and improving inspection efficiency. However, this structure also presents a number of issues, including the heavy weight of the gun tip and the high transmission force of the eddy current pusher, which prevents inspectors from holding the gun tip for extended periods. Furthermore, it also presents difficulties in centering the eddy current probe with the tubesheet, resulting in poor inspection stability and difficulty significantly improving inspection efficiency during semi-automatic inspection. Utility Model Content

[0005] To address the aforementioned shortcomings of the prior art, the present invention aims to provide a device for improving the stability of semi-automatic eddy current testing of heat transfer tubes in a tube-sheet structure. This device further enhances the efficiency and stability of eddy current testing. While improving the stability of semi-automatic eddy current testing, this method also enables automatic alignment of the eddy current probe and the tube bundle, eliminating the need for manual visual alignment and shortening testing time.

[0006] The technical means adopted by this utility model are as follows:

[0007] A device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with a tube-sheet structure comprises a handheld gun tip actuator, an eddy current flaw detector probe, a positioning aid, and a plane position fixing wheel. The positioning aid, eddy current flaw detector probe, and plane position fixing wheel are all mounted at the output end of the handheld gun tip actuator. The positioning aid is used to center the eddy current flaw detector probe after being inserted into the tube hole. The plane position fixing wheel is used to limit the positioning aid to maintain a preset depth in the tube hole.

[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 the 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 includes a rubber wheel, a bearing, a wheel seat and an extension rod, 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.

[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 legs are of a conical petal structure, and their maximum diameter is 95% of the inner diameter of the tube bundle to be inspected.

[0014] Compared with the existing technology, the utility model has the following advantages: the utility model discloses a device for improving the stability of semi-automatic eddy current detection of heat transfer tubes with 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 to quickly locate the tube hole to be detected. 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, thereby greatly improving the detection efficiency.

[0015] Compared with the existing technology, the present invention adds a positioning aid and a flat fixing wheel to the transmission device, so that the eddy current probe at the center of the gun head can quickly and accurately locate the center of the tube hole. This is more accurate than the existing technology of centering by the human eye, and avoids the eddy current probe 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 flat 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 existing technology, such as the heavy weight of the gun head itself, the high 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 semi-automatic detection. It is simple and convenient to use, and one adjustment is applicable 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

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the 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 labor.

[0017] Figure 1 A top view of the device of the present utility model;

[0018] Figure 2 A schematic diagram of detection and use of an embodiment of the present utility model;

[0019] 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

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention 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.

[0021] 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 in no way 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 making creative work are within the scope of protection of the present invention.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the 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 "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values ​​described in these embodiments 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 techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0024] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying 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 outline of each component itself.

[0025] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. 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 figures. For example, if the device in the 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.

[0026] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.

[0027] like Figure 1 、 Figure 2 As shown, an embodiment of the present invention discloses a device 22 for improving the stability of semi-automatic eddy current testing of heat transfer tubes in a tube-sheet structure. The device comprises a handheld gun actuator 1, an eddy current flaw detector probe, a positioning aid, and a planar position fixing wheel 3. The positioning aid, eddy current flaw detector probe, and planar position fixing wheel are all mounted at the output end of the handheld gun actuator. The positioning aid is used to center the eddy current flaw detector probe after insertion into the tube hole, and the planar position fixing wheel is used to limit the positioning aid to a predetermined depth within the tube hole. The eddy current flaw detector probe is disposed within the gun tip 5. After positioning, during testing, the eddy current probe extends from the center of the gun tip.

[0028] The handheld gun actuator used in this utility model is used to guide an eddy current probe (eddy current flaw detector probe) for inspecting heat exchanger tubes. To facilitate the installation of a positioning aid, a groove below the surface is machined into the front end of the gun housing of the handheld gun actuator. A clamp 4 is mounted on the groove, which facilitates the installation of the eddy current flaw detector probe, the positioning aid, and the flat position fixing wheel. In this embodiment, the machined dimensions of the groove in the gun actuator housing are comparable to those of the clamp, ensuring a tight fit between the clamp and the groove. When the clamp is fully secured to the gun groove, the gun will not move or loosen even when an external force of 500N or less is applied along the axial direction of the gun.

[0029] The positioning aid comprises two parallel positioning legs (2) of equal length. The clamp is a three-lobed structure, secured to the groove of the gun head actuator housing via locking bolts. The clamp is locked on both sides, simultaneously securing the two positioning leg brackets with locking bolts. The positioning legs are mounted on these brackets. In this embodiment, the positions of the two positioning legs and the gun head's central eddy current probe correspond to the dimensions and positions of the three tube holes in two adjacent layers of the tube sheet heat transfer tubes.

[0030] 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 via the bearing, and the wheel seat is mounted on the clamp via the extension rod. Specifically, the wheel seat is locked with the clamp via a bolt through the axial extension rod of the gun head.

[0031] 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.

[0032] 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.

[0033] The positioning leg is a conical split-petal structure made of brass, with 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 is connected to the clamp through a nut.

[0034] The utility model also discloses a method for using the device.

[0035] In this example, the eddy current testing instrument used was a SMART-5001 multi-frequency array eddy current tester manufactured by Edelson (Xiamen) Electronics Co., Ltd. It employed a shear wave phased array probe with a frequency range of 10 Hz to 10 MHz. The probes were array-penetrating eddy current probes, and the lengths of the probes and signal cables matched the tube bundle to be tested. The object to be tested was a tube-sheet heat exchanger 21 with a tube diameter of φ22 × 0.7 mm, a tube sheet thickness of 25 mm, and a tube bundle length of 12 meters.

[0036] The specific steps include:

[0037] S1. Use eddy current testing handheld gun head actuator; the thickness of the actuator barrel is 8mm;

[0038] S2. Use a three-petal structure clamp, and the position of the clamp petals should form a triangular correspondence with the heat exchanger tube hole;

[0039] 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, which can form a close fit between the clamp and the groove.

[0040] S4. Fix the clamp to the groove of the gun head with the locking bolt;

[0041] S5. Select the positioning legs and connect them to the clamp ears through threads and nuts on both sides;

[0042] S6. Use a flat position fixed wheel, one end of which is connected to the clamp ear through threads and nuts on both sides;

[0043] S7. Adjust the extension distance of the two positioning legs and the flat position fixing wheel using the threads and nuts. The difference between the extension distance of the two positioning legs and the position of the flat position fixing wheel is 2 / 3 of the thickness of the heat exchanger tube sheet. Tighten the positioning legs and flat position fixing wheel nuts to secure the position. In this embodiment, the difference is 16 mm. Tighten the positioning legs and flat position fixing wheel nuts to secure the position.

[0044] S8. Using the handheld gun actuator, insert the two positioning legs into the tube holes to be positioned. When the flat wheel is against the tube sheet surface, the positioning legs should extend no further than 2 / 3 of the tube sheet thickness, or 16 mm. Simultaneously, the eddy current test probe at the center of the gun tip should be aligned with the center of the tube hole to be tested. When the handheld gun actuator applies a vertical force to the tube sheet plane, the positioning aid exhibits no significant axial movement. This completes the debugging of this method. In the figure, the six circular holes in two rows represent the holes to be tested. The positioning legs are aligned with the gun tip and, relative to the flat wheel, are located one level below the holes to be tested.

[0045] Furthermore, after S8, the following steps are also included:

[0046] S9. When conducting 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 the eddy current detector and the pusher, insert the two positioning legs into the tube hole used for positioning, press the flat wheel against the tube sheet surface, align the eddy current detection probe at the center of the gun head with the center of the tube hole to be tested, turn on the handheld gun head transmission handle switch, run the pusher, and send the eddy current probe through the center of the gun barrel into the tube hole to be tested. 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 testing of the tube hole and tube bundle is completed.

[0047] 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 deviate the essence of the corresponding technical solutions 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 testing of heat transfer tubes in a tube-sheet structure, characterized in that: It includes a handheld gun tip actuator, an eddy current flaw detector probe, a positioning aid and a plane position fixing wheel. The positioning aid, eddy current flaw detector probe and plane position fixing wheel are all installed at the output end of the handheld gun tip actuator. 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 testing of heat transfer tubes with a tube sheet structure according to claim 1, characterized in that: The front end of the handheld gun head actuator is machined with a groove below the surface, on which a clamp is installed, through which the eddy current flaw detector probe, positioning aid and plane position fixing wheel are installed.

3. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes with a 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 and fixes the two positioning leg brackets at the same time by locking bolts. 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 a 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 mounted on the wheel seat via the bearing, and the wheel seat is mounted on the clamp via the extension rod.

5. The device for improving the stability of semi-automatic eddy current testing of heat transfer tubes in a 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. 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 can be adjusted.

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

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