Leak detection device for multiple groups of heat exchange tubes of heat exchanger and use method thereof

Abstract

The present invention discloses a leak detection device for multiple groups of heat exchange tubes in a heat exchanger and a method for use thereof. The device comprises a column, two first telescopic rods, two second telescopic rods, a plurality of plugs, and a plurality of air inlet heads. The first telescopic rod abuts against the plugs and the air inlet heads via a mounting base, and the second telescopic rod abuts against the inner wall of the steam chamber on the other side to provide thrust. An air compressor inputs air pressure into the heat exchange tubes and then maintains the pressure for detection. This leak detection tool can be assembled once to perform single-hole and multi-hole leak detection operations, thereby improving work efficiency. Moreover, this leak detection tool is small in size and can perform pressure leak detection operations at all positions in the steam chamber without the problem of spatial interference. The operator can operate the device alone, which reduces labor intensity and the need for coordination. This invention is used in the field of nuclear power unit maintenance.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power unit maintenance, and in particular to a leakage detection device for multiple groups of heat exchange tubes of a heat exchanger and a use method thereof. Background Art

[0002] The moisture separator reheater (hereinafter referred to as MSR: Moisture Separator Reheater) is a key large-scale equipment unique to the conventional island of a nuclear power plant to improve the overall thermal efficiency of the power plant and protect the steam turbine. Its main function in the conventional island reheating system of a nuclear power plant is to save energy and improve the efficiency of the steam turbine. This equipment is integrated with the steam turbine and generator, and is one of the important core equipment in the conventional island equipment of nuclear power plants. According to operational requirements, nuclear power plant units need to be shut down for major repairs regularly every 12 to 18 months. During this period, power plant staff need to quickly and accurately pressure test the MSR piping system for leaks to ensure the normal operation of the equipment. The leak detection parts of the MSR piping system are as follows Figure 1 shown.

[0003] MSR includes a steam-type inner cavity, a heat exchange tube system, a horizontal partition, and several pipes and channels. The heat exchange tube system is located on the left and includes several U-shaped heat exchange tubes. Figure 1 What you see in the figure is the upper inlet and lower outlet of the U-shaped heat exchange tube. Figure 2 yes Figure 1 From the right view, you can see that the MSR is about 3 meters long, with manholes on the left and right sides. During pressure testing, all tools and personnel enter and exit through these manholes. Extra-large tools need to be disassembled and assembled.

[0004] Existing leak detection methods require an operator to manually hold the corresponding plugs against the corresponding tube holes from below the horizontal baffle while simultaneously applying pressure to inspect one or a few tubes. The horizontal baffle obstructs the space below, increasing labor intensity and making the operation extremely inconvenient and inefficient. Furthermore, the pressure guns interfere with each other at both ends of the steam chamber, preventing inspection of all heat exchange tubes. Summary of the Invention

[0005] The object of the present invention is to provide a leak detection device for multiple groups of heat exchange tubes of a heat exchanger, which is easy to use and has high detection efficiency, and a method for using the same.

[0006] The technical solution adopted by the present invention is:

[0007] A leak detection device for multiple groups of heat exchange tubes in a heat exchanger, comprising: a column for providing supporting force; two first telescopic rods, the two first telescopic rods are respectively located on the upper and lower sides of the left side of the column, the two first telescopic rods each include a fixed end connected to the column and a movable end movably set on the fixed end; two second telescopic rods, the two second telescopic rods are respectively located on the upper and lower sides of the right side of the column, the two second telescopic rods each include a fixed end connected to the column and a movable end movably set on the fixed end; two mounting seats are respectively arranged at the movable ends of the first telescopic rods, one of the mounting seats is provided with a number of plugs that can block the pipe openings of the heat exchange tubes, and the other mounting seat is provided with an air inlet head of the same number as the plugs that can be inserted into the pipe openings of the heat exchange tubes, and each of the air inlet heads has an air inlet interface for connecting to the air supply pipe; two buffer members are respectively arranged at the movable ends of the second telescopic rods for connecting to the inner cavity.

[0008] As an improvement of the above solution, the air intake head includes a body and an air intake interface fixed on the side of the body, the air intake interface is connected to the center of the body to form an air supply channel, and a rubber ring is provided at the top of the body.

[0009] As an improvement to the above solution, the plug is a rotating body structure, provided with a plurality of annular shoulders or annular grooves, and a rubber ring is provided at the top of the plug.

[0010] As an improvement to the above solution, the fixed end of the first telescopic rod is a cylindrical structure, and the side wall of the cylindrical structure is provided with at least two long notches, which extend in the axial direction on the cylindrical structure and then bend to the circumferential direction and continue to extend. This part of the long notch in the circumferential direction is on the side away from the column, and the side wall of the movable end of the first telescopic rod is provided with a protrusion that can be embedded in the long notch, and the movable end is telescopically deflected relative to the fixed end under the guidance of the long notch.

[0011] As an improvement to the above solution, the side of the buffer component away from the column is a curved surface that can fit the inner cavity.

[0012] As an improvement to the above solution, the axis lines of the two first telescopic rods and the two second telescopic rods are all in the same plane.

[0013] As an improvement to the above solution, a temporary support rod is further included, which is arranged on the lower side of one of the first telescopic rods to provide supporting force.

[0014] As an improvement to the above solution, an air compressor is further included, wherein the output end of the air compressor is connected to each air intake head through each air supply pipe.

[0015] A method for using the leak detection device comprises the following steps:

[0016] S1. Open at least one manhole, remove the exhaust flange, expansion joint, and orifice tube, prepare the air compressor, install the multi-way valve, shut-off valve, and air supply pipe, and check the integrity and sealing of each pipeline, valve, inlet head, and plug.

[0017] S2. Place the leak detection device into the inner cavity, keeping all plugs and air inlet heads in the same vertical plane. Insert several plugs into the corresponding upper or lower heat exchange tubes, and several air inlet heads into the heat exchange tubes on the other side. Extend the two first telescopic rods to tighten the plugs and air inlet heads. Extend the two second telescopic rods to tighten the inner cavity. Connect each air supply pipe to the corresponding air inlet head.

[0018] S3. Apply pressure with an air compressor. If the heat exchange tube maintains pressure continuously and there are no abnormal noises, the test is considered passed. After the test, release the air pressure in the heat exchange tube, loosen the two first and two second telescopic rods, and move the leak detection device to the next station.

[0019] S4. Repeat the above steps S2 and S3 to complete the inspection of other heat exchange tubes.

[0020] The present invention has the following beneficial effects: the leak detection tool can be assembled once to perform leak detection on both single and multiple holes, improving work efficiency. Furthermore, the leak detection tool is compact and can be used to perform pressure leak detection at all locations within the steam chamber without spatial interference. It can be operated by a single operator, reducing labor intensity and the need for coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings:

[0022] Figure 1 is a front cross-sectional view of a heat exchanger in this embodiment;

[0023] Figure 2 is a right side sectional view of a heat exchanger in this embodiment;

[0024] Figure 3 is a perspective view of the leak detection device in this embodiment;

[0025] Figure 4 This is a diagram of the leak detection device in this embodiment in use;

[0026] Figure 5 is a cross-sectional view of the air intake head in this embodiment;

[0027] Figure 6 is a cross-sectional view of the plug in this embodiment;

[0028] Figure 7 It is a three-dimensional view of the fixed end of the first telescopic rod in this embodiment. DETAILED DESCRIPTION

[0029] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0030] In the description of this invention, "several" means one or more, "more" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0031] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0032] Reference Figures 1 to 7 The present invention is a leak detection device and a method for use of multiple groups of heat exchange tubes in a heat exchanger.

[0033] like Figure 1 As shown, on the left side of the steam chamber 11 are a plurality of heat exchange tubes 12. In this embodiment, the heat exchange tubes 12 are U-shaped. Figure 1 The bend of the heat exchange tube 12 is not shown. What can be seen is that the inlet or outlet of the heat exchange tube 12 is located in the upper half of the steam chamber 11, and the outlet or inlet of the heat exchange tube 12 is located in the lower half. Access is through a central manhole 13. A horizontal partition 14 is typically provided within the steam chamber 11 for standing. When using traditional testing methods, the lower heat exchange tube 12 is typically blocked, and the operator uses a pressure gun to pressurize the corresponding upper end of the heat exchange tube 12. However, the pressure gun is not convenient for reaching the left and right edges, which can easily cause interference. Figure 2 It can be seen that a steam chamber 11 has a large number of heat exchange tubes 12. The operator slowly inspects from one side to the other, which has low inspection efficiency and high labor intensity.

[0034] like Figure 3As shown, the leak detection device mainly includes a column 30, two first telescopic rods 40, two second telescopic rods 50, a plurality of plugs 61, and a plurality of air inlet heads 62. The two first telescopic rods 40 are located on the upper and lower sides of the left side of the column 30, and the two second telescopic rods 50 are located on the upper and lower sides of the right side of the column 30. The first telescopic rod 40 includes a fixed end 41 connected to the column 30 and a movable end 42 movably mounted on the fixed end 41. The second telescopic rod 50 also includes a fixed end connected to the column 30 and a movable end movably mounted on the fixed end. A mounting base 60 is provided on the movable end 42 of the first telescopic rod 40, one of which is provided with a plurality of air inlet heads 62, and the other mounting base 60 is provided with a number of plugs 61 equal to the number of air inlet heads 62.

[0035] like Figure 4 As shown, during use, the plurality of air inlet headers 62 and the plurality of plugs 61 are all located in the same vertical plane, allowing simultaneous testing of multiple heat exchange tubes 12 in a vertical row. The movable end 42 of the first telescopic rod 40 is extended to an appropriate length, allowing the air inlet headers 62 and plugs 61 to be inserted into the heat exchange tubes 12. The air inlet headers 62 are used to input air pressure, while the plugs 61 are used to prevent air pressure leakage. The movable end of the second telescopic rod 50 is extended to an appropriate length to abut against the inner cavity of the steam chamber 11, providing a force for the plugs 61 and air inlet headers 62 to be inserted into the heat exchange tubes 12.

[0036] like Figure 5 and Figure 6 As shown, the air inlet head 62 comprises a body and an air inlet port fixed to the side of the body. The air inlet port is inserted into the body and then welded to form an integral structure. The left side of the air inlet head 62 is used to insert the heat exchange tube 12. Overall, the air inlet port is approximately L-shaped, connecting to the center of the body to form an air supply channel. Since the plug 61 only needs to be inserted into the heat exchange tube 12, its structure is simpler and can be made of solid material. In other embodiments, the air inlet head 62 can also be a straight tube. In this case, the structure of the mounting base 60 must be appropriately adjusted to facilitate the connection of the air supply tube. Figure 3 A schematic diagram of the air compressor 20 can be seen in the figure. The air compressor 20 first delivers the air pressure to a main pipeline, and then the main pipeline delivers the air pressure to each air intake head 62 through various branches.

[0037] In this embodiment, the mounting seat 60 is a channel steel, and the number and orientation of the plugs 61 and the air inlet heads 62 are designed according to the spacing and number of the heat exchange tubes 12, and then the plugs 61 and the air inlet heads 62 are welded to the mounting seat 60; in other embodiments, the mounting seat 60 can be further optimized, and the plugs 61 and the air inlet heads 62 are both connected to the mounting seat 60 in a detachable manner, for example, a dovetail groove is provided on the mounting seat 60, and the plugs 61 and the air inlet heads 62 are also provided with corresponding structures so that the two are clamped to each other.

[0038] In this embodiment, the body of the air inlet head 62 and the plug 61 are both of a rotating body structure, which facilitates the provision of a plurality of annular shoulders or annular grooves on the body and the plug 61. O-type rubber rings are further provided on the annular grooves. Figure 5 It can be seen that the middle position of the body and the middle position of the plug 61 are both large-area shaft shoulders, which can properly support the O-type rubber ring and limit the extreme position of the O-type sealing ring.

[0039] The first telescopic rod 40 and the second telescopic rod 50 are mainly used to complete the telescopic and tightening function, and can be optionally equipped with an electric push rod, a hydraulic rod, or the like. Figure 7 As shown, this embodiment employs a manually retractable telescopic rod. The fixed end 41 of the first telescopic rod 40 is cylindrical in structure. Two long notches 43 are provided on its sidewalls, forming a 180° angle between the two notches. The notches extend axially along the cylindrical structure and then bend to continue extending circumferentially. The axial extension angle is 90°, and the circumferential portion of the notches is located away from the column 30. If three notches are provided, the angle between adjacent notches can be 120°, reducing the circumferential extension angle. The movable end 42 of the first telescopic rod 40 is a cylindrical structure that inserts into the fixed end 41. Its sidewalls are provided with protrusions that fit into the notches 43. Guided by the notches 43, the movable end 42 telescopes and deflects relative to the fixed end 41. Once the movable end 42 is in position, the outermost notch 43 restricts its retraction, and tightening the set screw on the movable end 42 locks it into place.

[0040] Of course, a lever or pull rod can also be used between the fixed end 41 and the movable end 42 to facilitate quick assembly and disassembly. The second telescopic rod 50 can adopt the same structure as the first telescopic rod 40; however, in this embodiment, the second telescopic rod 50 adopts a threaded telescopic design. The fixed end and movable end of the second telescopic rod 50 are connected by a screw, which is equipped with a nut. Rotating the nut pushes the movable end out.

[0041] Preferably, in order to make the force on the first telescopic rod 40 more stable, the axis lines of the two first telescopic rods 40 and the two second telescopic rods 50 are all in the same plane.

[0042] Preferably, to allow the movable end of the second telescopic rod 50 to better fit within the interior of the steam chamber 11, a buffer 63 is provided at the movable end of the second telescopic rod 50. The side of the buffer 63 facing away from the column 30 is a curved surface that fits within the interior, or the buffer 63 is spherical. The buffer 63 is primarily adjusted based on the interior structure, and other structures are not described in detail here.

[0043] Preferably, in order to maintain the balance of the entire leak detection device, a temporary support rod 70 can be additionally provided. The temporary support rod 70 is used to support the first telescopic rod 40, generally the fixed end 41. The column 30 and the temporary support rod 70 can form two support points; after arranging the temporary support rod 70, only the temporary support rod 70 can be used for support, and the column 30 is suspended in the air. The temporary support rod 70 is generally provided on the first telescopic rod 40 located on the lower side, and the temporary support rod 70 also adopts a telescopic rod to facilitate height adjustment; for example, a vertical screw is welded to the fixed end 41 of the first telescopic rod 40, and a base is threadedly connected to the screw, and its support height can be adjusted by rotating the base.

[0044] As for how to use it, please refer to the following instructions.

[0045] S1. Open at least one side of the manhole 13, remove the exhaust flange, expansion joint and throttle tube, prepare the air compressor 20, configure the multi-way valve, stop valve, air pipe, check the integrity and sealing of each pipeline, each valve, each inlet head 62 and each plug 61;

[0046] S2. Place the leak detection device into the inner cavity, ensuring that all plugs 61 and air inlet headers 62 are in the same vertical plane. Insert several plugs 61 into the corresponding upper or lower heat exchange tubes 12, and insert several air inlet headers 62 into the heat exchange tubes 12 on the other side. Extend the two first telescopic rods 40 to tighten the plugs 61 and air inlet headers 62. Extend the two second telescopic rods 50 to tighten the inner cavity. Connect each air supply tube to the corresponding air inlet header 62.

[0047] S3. Pressurize the air compressor 20 to an output pressure of 0.6-0.8 MPa. If the heat exchange tube 12 maintains pressure continuously and there is no abnormal noise, the test is passed. After the test is completed, the air pressure in the heat exchange tube 12 is released, the two first telescopic rods 40 and the two second telescopic rods 50 are released, and the leak detection device is moved to the next station.

[0048] S4. Repeat the above steps S2 and S3 to complete the detection of other heat exchange tubes 12.

[0049] This leak detection tool can be assembled once to perform leak detection operations on single or multiple holes, improving work efficiency. Furthermore, this leak detection tool is compact and can perform pressure leak detection operations at all positions within the steam chamber 11 without spatial interference. It can be operated by a single operator, reducing labor intensity and the need for coordination.

[0050] Of course, the present invention is not limited to the above-mentioned embodiments. Combinations of different features of the above-mentioned embodiments can also achieve good results. Those skilled in the art can make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all within the scope defined by the claims of this application.

Claims

1. A leak detection device for multiple groups of heat exchange tubes in heat exchangers, characterized in that include: Columns, providing support; Two first telescopic rods, the two first telescopic rods are respectively located on the upper and lower sides of the left side of the column, and the two first telescopic rods each include a fixed end connected to the column and a movable end movably disposed on the fixed end; Two second telescopic rods, the two second telescopic rods are respectively located on the upper and lower sides of the right side of the column, and the two second telescopic rods each include a fixed end connected to the column and a movable end movably disposed on the fixed end; Two mounting seats are respectively provided at the movable ends of the first telescopic rod, one of the mounting seats is provided with a plurality of plugs capable of sealing the pipe openings of the heat exchange tubes, and the other mounting seat is provided with an air inlet head having the same number of plugs as the plugs and capable of being inserted into the pipe openings of the heat exchange tubes, each of the air inlet heads having an air inlet interface for connecting to the air supply pipe; Two buffer members are respectively provided at the movable ends of the second telescopic rod and are used to connect to the inner cavity; Also included is a temporary support rod, which is arranged on the lower side of one of the first telescopic rods to provide support force; It also includes an air compressor, wherein the output end of the air compressor is connected to each air inlet head through each air supply pipe; In which, when in use, several of the air inlet heads and several of the plugs are in the same vertical plane, and multiple heat exchange tubes in this vertical column are detected at one time; the movable end of the first telescopic rod is extended to an appropriate length, and the air inlet head and the plug are inserted into the heat exchange tube, the air inlet head is used to input air pressure, and the plug is used to prevent air pressure leakage; the movable end of the second telescopic rod is extended to an appropriate length to support the inner cavity of the steam chamber, providing force for the plug and the air inlet head to be stably inserted into the heat exchange tube.

2. The leak detection device according to claim 1, characterized in that: The air intake head includes a body and an air intake interface fixed on the side of the body. The air intake interface is connected to the center of the body to form an air supply channel. A rubber ring is provided at the top of the body.

3. The leak detection device according to claim 2, characterized in that: The plug is a rotating body structure and is provided with a plurality of annular shoulders or annular grooves. A rubber ring is provided at the top of the plug.

4. The leak detection device according to claim 3, characterized in that: The fixed end of the first telescopic rod is a cylindrical structure, and the side wall of the cylindrical structure is provided with at least two long notches. The long notches extend in the axial direction on the cylindrical structure and then bend to continue extending in the circumferential direction. This part of the long notch in the circumferential direction is on the side away from the column. The side wall of the movable end of the first telescopic rod is provided with a protrusion that can be embedded in the long notch. The movable end is telescopically deflected relative to the fixed end under the guidance of the long notch.

5. The leak detection device according to claim 4, characterized in that: The side of the buffer component away from the column is a curved surface that can fit the inner cavity.

6. The leak detection device according to claim 1, characterized in that: The axis centers of the two first telescopic rods and the two second telescopic rods are all in the same plane.

7. A method for using the leak detection device according to any one of claims 1 to 6, characterized in that The following steps are involved: S1. Open at least one manhole, remove the exhaust flange, expansion joint, and orifice tube, prepare the air compressor, install the multi-way valve, shut-off valve, and air supply pipe, and check the integrity and sealing of each pipeline, valve, inlet head, and plug. S2. Place the leak detection device into the inner cavity, keeping all plugs and air inlet heads in the same vertical plane. Insert several plugs into the corresponding upper or lower heat exchange tubes, and several air inlet heads into the heat exchange tubes on the other side. Extend the two first telescopic rods to tighten the plugs and air inlet heads. Extend the two second telescopic rods to tighten the inner cavity. Connect each air supply pipe to the corresponding air inlet head. S3. Apply pressure with an air compressor. If the heat exchange tube maintains pressure continuously and there are no abnormal noises, the test is considered passed. After the test, release the air pressure in the heat exchange tube, loosen the two first and two second telescopic rods, and move the leak detection device to the next station. S4. Repeat the above steps S2 and S3 to complete the inspection of other heat exchange tubes.

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