Leak detection device for heat exchange tube leak detection and use method

Abstract

The present invention discloses a leak detection device for detecting leaks in heat exchange tubes and a method for using the device. The leak detection devices of the present invention are installed at both ends of the heat exchange tubes. One leak detection device is used to seal the heat exchange tubes, and the other leak detection device is used to input air pressure for detection. An internal connection portion is connected to the heat exchange tubes, which acts as a force support point for the heat exchange tubes themselves. An external connection portion is further provided based on the above support point. This leak detection device can be installed on the heat exchange tubes and can also serve as a transition connection. In this case, the leak detection process of each heat exchange tube is relatively independent, and a stable connection relationship can be maintained without the use of other support points or brackets. This invention is used in the field of heat exchangers.

Description

Technical Field

[0001] The present invention relates to the field of heat exchangers, and in particular to a leakage detection device for detecting leakage of heat exchange tubes and a use method thereof. Background Art

[0002] The current development trend for heat exchangers is toward larger, more efficient, and more compact designs, with larger heat exchange areas and longer tube lengths. However, due to limitations in the manufacturing capabilities of heat exchanger manufacturers, many tubes often require splicing. For applications involving high pressure, toxic media, flammable and explosive media, or harsh operating conditions, butt joints often require helium mass spectrometry leak detection in addition to radiographic or ultrasonic testing, requiring a vacuum or pressure environment to be created within the tube.

[0003] There are two main existing technologies. One is to weld plugs or adapters at the ends of the heat exchange tubes, such as Figure 1 As shown; the second is to use an expansion gun to extend into the end of the heat exchange tube, and then use hydraulic pressure to achieve extrusion sealing between the expansion gun and the end of the heat exchange tube, as shown Figure 2 As shown. The first existing technology uses a plug or adapter welded to the end of the heat exchange tube. The heat exchange tube needs to reserve a length margin. After the helium mass spectrometer leak detection is completed, the plug is removed together with a small amount of heat exchange tube. The heat exchange tube is finally processed after the heat-affected zone of the weld at the end of the heat exchange tube is removed. With this method, on the one hand, the length of the heat exchange tube needs to be reserved, which will cause length waste and increase costs; on the other hand, it involves welding, cutting, processing, and non-destructive testing, with many processes and low efficiency, which is not conducive to reuse. Non-destructive testing and welding also involve personnel qualification requirements and management. The second existing technology involves expansion guns, which are extremely expensive. If the diameter of the heat exchange tube is small, the expansion rod diameter is small, and it is difficult to purchase, and there are even no corresponding specifications.

[0004] In actual operation, helium mass spectrometry leak detection is performed after butt welding of heat exchange tubes. The following four requirements are placed on the sealing structure of the heat exchange tube ends:

[0005] A heat exchanger often has many heat exchange tubes, and the sealing structure at the end of the heat exchange tubes must be reusable and easy to disassemble and assemble.

[0006] The design of extra-long heat exchange tubes also involves the welding of reducers, requiring the sealing structure at the end of the heat exchange tube to be suitable for a variety of tube diameters;

[0007] If the heat exchange tube manufacturer does not have the qualification for helium mass spectrometry leak detection, the heat exchanger manufacturer is required to carry the helium mass spectrometry leak detection equipment and heat exchange tube end sealing tooling to the heat exchange tube manufacturer for mass spectrometry leak detection. The heat exchange tube end sealing structure should be easy to carry;

[0008] The sealing structure at the end of the heat exchange tube also facilitates the connection of helium leak detection equipment. Summary of the Invention

[0009] The object of the present invention is to provide a leak detection device and a method for use for leak detection of heat exchange tubes that meet at least one of the above four requirements.

[0010] The technical solution adopted by the present invention is:

[0011] A leak detection device for detecting leaks in heat exchange tubes is sleeved on the heat exchange tubes and includes an inner connecting portion, which is detachably fixed to the heat exchange tubes and has a first slot hole allowing the heat exchange tubes to pass through; an outer connecting portion, which is detachably fixed to the inner connecting portion and has a second slot hole allowing the heat exchange tubes to pass through, the first slot hole and the second slot hole being coaxial; a threaded head, which is installed on a side of the outer connecting portion away from the inner connecting portion, the threaded head is coaxial with the second slot hole, and the inner diameter of the threaded head is larger than the outer diameter of the heat exchange tube to be received.

[0012] Since the internal connection part adopts a detachable connection, the leak detection device can be used repeatedly. At the same time, the leak detection device can be designed with different sizes according to the size of the heat exchange tube and can even be used for different diameter tubes.

[0013] As an improvement to the above solution, the threaded head is connected to a plug for sealing or an adapter for connecting to a helium mass spectrometer leak detection device.

[0014] As an improvement to the above solution, the inner connecting portion includes an upper clip and a lower clip, the upper and lower clips being detachably connected. A recessed arcuate groove for accommodating the heat exchange tube is provided on the surface between the upper and lower clips, with a first slot defined between the two arcuate grooves. When the upper and lower clips are connected, the two arcuate grooves respectively clamp the upper and lower sides of the heat exchange tube.

[0015] As an improvement to the above solution, the external connection portion includes a first vertical plate and a second vertical plate. The left side of the first vertical plate is connected to the upper or lower clip, and the right side of the first vertical plate is connected to the second vertical plate. A through-hole is provided between the first and second vertical plates, and the two through-holes define a second slot. The threaded head is mounted on the second vertical plate. Introducing a heat exchange tube as a reference, the heat exchange tube is perpendicular to the first and second vertical plates.

[0016] As an improvement to the above solution, the upper clamping piece and the lower clamping piece are connected by a bolt group.

[0017] As an improvement to the above solution, the first vertical plate and the upper clamping piece or the lower clamping piece are fixed by welding, and the first vertical plate and the second vertical plate are connected by a bolt group.

[0018] As an improvement to the above solution, rubber pads are provided on the surfaces of the two arc-shaped grooves and the inner wall of the second vertical plate.

[0019] A method for using the leak detection device described above includes the following steps: preparing two leak detection devices and a heat exchange tube, wherein the two leak detection devices are respectively located at the front and rear ends of the heat exchange tube, the inner connecting part is installed on the heat exchange tube, and the outer connecting part is connected to the inner connecting part. At this time, one end of the heat exchange tube has passed through the first slot, the second slot and the threaded head, a plug is installed on one of the threaded heads, and an adapter for connecting to a helium mass spectrometer leak detection device is installed on the other threaded head, and the adapter is connected to the helium mass spectrometer leak detection device to obtain air pressure.

[0020] Beneficial effect: The internal connection part is connected to the heat exchange tube, which is equivalent to the heat exchange tube itself as a force fulcrum. Based on the above fulcrum, the external connection part is further set. This leak detection device can be installed on the heat exchange tube and can also serve as a transition connection piece. At this time, the leak detection process of each heat exchange tube is relatively independent, and a stable connection relationship can be maintained without the help of other fulcrums or brackets. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 1 Schematic diagram of a heat exchange tube welding plug in a conventional embodiment;

[0023] Figure 2 Schematic diagram of inserting a heat exchange tube into an expansion gun according to a conventional embodiment;

[0024] Figure 3 is a schematic diagram of the heat exchange tube of this embodiment combined with two leak detection devices;

[0025] Figure 4 This is an exploded view of the heat exchange tube and the inner connecting portion of this embodiment;

[0026] Figure 5 This is an exploded view of the heat exchange tube, the inner connecting portion, and the outer connecting portion of this embodiment;

[0027] Figure 6 This is an enlarged view of the heat exchange tube of this embodiment combined with a leak detection device;

[0028] Figure 7 It is a cross-sectional view of the heat exchange tube of this embodiment combined with a leak detection device. 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 relates to a leak detection device and a method for use for leak detection of heat exchange tubes.

[0033] The leak detection device is mounted on the heat exchange tube 10, as shown in FIG. Figure 3 As shown, the leak detection devices of the present application are installed at both ends of the heat exchange tube 10, one leak detection device is used to seal the heat exchange tube 10, and the other leak detection device is used to input air pressure for detection. The leak detection device includes an inner connection part and an outer connection part, the inner connection part is detachably fixed to the heat exchange tube 10, and the outer connection part is detachably fixed to the heat exchange tube 10. The inner connection part and the outer connection part are respectively provided with a first slot and a second slot, and the two slots are coaxial. The outer connection part is provided with a threaded head 40, and the outer wall of the threaded head 40 has a thread for connecting a sealed plug or for connecting an adapter 50 for a helium mass spectrometer leak detection device. When in use, the heat exchange tube 10 passes through the inner connection part and the outer connection part at the same time.

[0034] The internal connection is connected to the heat exchange tube 10 to form a new fulcrum, upon which the external connection is installed. This application solution creatively utilizes the heat exchange tube 10 as a fulcrum, upon which a plug or adapter 50 is independently provided. The leak detection device is easy to install and flexible to use. Because the internal connection is detachable, the leak detection device can be reused. Furthermore, the leak detection device can be designed with different sizes based on the size of the heat exchange tube 10, and can even be used with pipes of different diameters.

[0035] The internal connection includes an upper clip 21 and a lower clip 22, which are detachably connected. A recessed arcuate groove for receiving the heat exchange tube 10 is provided on the surface between the upper and lower clips 21, 22. A first slot is defined between the two arcuate grooves. When the upper and lower clips 21, 22 are connected, the two arcuate grooves respectively clamp the upper and lower sides of the heat exchange tube 10.

[0036] like Figure 4As shown, in order to increase the connection area with the heat exchange tube 10, the upper clip 21 and the lower clip 22 are appropriately extended along the axial direction of the heat exchange tube 10. The lower clip 22 is thicker than the upper clip 21. In this case, the upper clip 21 is a sheet material, and the upper clip 21 will bend along the direction of the arc groove. In this embodiment, the left and right ends of the upper clip 21 and the lower clip 22 are connected and fixed by a bolt assembly. In other embodiments, one side of the upper clip 21 and the lower clip 22 are hinged to each other in a flip-up manner, and the other side of the upper clip 21 and the lower clip 22 can be connected by a lock or a pin.

[0037] Preferably, in order to avoid abrasion of the heat exchange tube 10 , rubber pads 60 are provided on the arc grooves of the upper clamping piece 21 and the lower clamping piece 22 .

[0038] The external connection portion includes a first vertical plate 31 and a second vertical plate 32. The left side of the first vertical plate 31 is connected to the upper clip 21 or the lower clip 22, and the right side of the first vertical plate 31 is connected to the second vertical plate 32. A through-hole is provided between the first and second vertical plates 31, 32, and the two through-holes define a second slot. The threaded head 40 is mounted on the second vertical plate 32. For reference, the heat exchange tube 10 is introduced, and the heat exchange tube 10 is perpendicular to the first and second vertical plates 31, 32. In this embodiment, the front of the first vertical plate 31 is U-shaped, with an upwardly open notch in the middle. The heat exchange tube 10 can also pass through this notch.

[0039] like Figure 5 As shown, considering the sufficient thickness of the lower clamping plate 22, the first vertical plate 31 is welded to the lower clamping plate 22. The first and second vertical plates 31 and 32 are fixed together by a bolt assembly. Accordingly, the left and right sides of the first clamping plate are provided with oblong grooves, and the second clamping plate is provided with screw holes. It can be seen that the thickness of the second vertical plate 32 is much greater than that of the first vertical plate 31, because the perforations of the second vertical plate 32 primarily serve to enclose the heat exchange tubes 10. Figure 5 As can be seen in the figure, the perforation of the second vertical plate 32 is a stepped hole. The large-diameter end of the stepped hole is close to the first vertical plate 31, where a rubber pad 60 is placed to wrap the heat exchange tube 10. The small-diameter end of the stepped hole is a clearance fit with the heat exchange tube 10. The rubber pad here is annular.

[0040] like Figure 6 and 7 As shown, an adapter 50 is mounted on the threaded head 40, and a gasket 51 is provided between the adapter 50 and the heat exchange tube 10 to prevent the heat exchange tube 10 from directly pressing against the inner wall of the adapter 50. Generally, the adapter 50 is welded and fixed to the second vertical plate 32.

[0041] The method for using the leak detection device includes the following steps: preparing two leak detection devices and a heat exchange tube 10, the two leak detection devices are respectively located at the front and rear ends of the heat exchange tube 10, the inner connection part is installed on the heat exchange tube 10, and the outer connection part is connected to the inner connection part. At this time, one end of the heat exchange tube 10 has passed through the first slot, the second slot and the threaded head 40, a plug is installed on one of the threaded heads 40, and an adapter 50 for connecting to a helium mass spectrometer leak detection device is installed on the other threaded head 40. The adapter 50 is connected to the helium mass spectrometer leak detection device to obtain air pressure.

[0042] 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 heat exchange tube leak detection, characterized in that: It is installed on the heat exchange tube, including The inner connecting portion is detachably fixed to the heat exchange tube and has a first slot hole allowing the heat exchange tube to pass through; The outer connecting portion is detachably fixed to the inner connecting portion and has a second slot hole for allowing the heat exchange tube to pass through, wherein the first slot hole and the second slot hole are coaxial; A threaded head is installed on a side of the outer connecting part away from the inner connecting part, the threaded head is coaxial with the second slotted hole, the inner diameter of the threaded head is larger than the outer diameter of the heat exchange tube to be received, the threaded head is connected to a plug for sealing or an adapter for connecting a helium mass spectrometer leak detection device, the inner connecting part includes an upper clamp and a lower clamp, the upper clamp and the lower clamp are detachably connected, the surface between the upper clamp and the lower clamp is provided with a concave arc-shaped groove for receiving the heat exchange tube, and a first slotted hole is defined between the two arc-shaped grooves, the upper clamp and the lower clamp are both extended along the axial direction of the heat exchange tube, the lower clamp is thicker than the upper clamp, the upper clamp is a sheet material, and the upper clamp bends as the direction of the arc groove changes; The external connection portion includes a first vertical plate and a second vertical plate, the left side of the first vertical plate is connected to the upper clamping piece or the lower clamping piece, the right side of the first vertical plate is connected to the second vertical plate, a through hole is provided between the first vertical plate and the second vertical plate, the two through holes define a second slot, the through hole of the second vertical plate is a stepped hole, the large diameter end of the stepped hole is close to the first vertical plate, and the threaded head is installed on the second vertical plate; The first vertical plate is fixed to the upper clamping piece or the lower clamping piece by welding, and the first vertical plate is connected to the second vertical plate by a bolt group.

2. The leak detection device for heat exchange tubes according to claim 1, characterized in that: The upper clamping piece and the lower clamping piece are connected by a bolt group.

3. The leak detection device for heat exchange tube leak detection according to claim 1, characterized in that: The surfaces of the two arc-shaped grooves and the inner wall of the second vertical plate are both provided with rubber pads.

4. A method for using the leak detection device according to any one of claims 1 to 3, characterized in that The invention comprises the following steps: preparing two leak detection devices and a heat exchange tube, wherein the two leak detection devices are respectively located at the front and rear ends of the heat exchange tube, the inner connection part is installed on the heat exchange tube, and the outer connection part is connected to the inner connection part. At this time, one end of the heat exchange tube has passed through the first slot, the second slot and the threaded head, a plug is installed on one of the threaded heads, and an adapter for connecting to a helium mass spectrometer leak detection device is installed on the other threaded head. The adapter is connected to the helium mass spectrometer leak detection device to obtain air pressure.

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