Helium leak detection device for welding seam of special-shaped tube plate of heat exchanger tube

Abstract

The utility model discloses a helium leak detection device for a welding seam of a special-shaped tube plate of a heat exchanger tube, which comprises a sealing cover, a plurality of pressing plates and a plurality of connecting plates, the number of the pressing plates and the number of the connecting plates are equal, each pressing plate is correspondingly provided with one connecting plate, and the sealing cover is arranged on the sealing cover. The multiple pressing plates are arranged above the sealing cover and evenly arranged in the length direction of the sealing cover. The sealing cover is a groove body, and the grooving position of the sealing cover is arranged on the whole welding seam area above the special-shaped tube plate and matched with the whole welding seam area of the special-shaped tube plate in size. A plurality of connecting plates are arranged below the special-shaped tube plate, the shape of the lower portion of the special-shaped tube plate is matched with the shape of the upper ends of the connecting plates, and the connecting plates are arranged on the non-tube-hole portion of the tube hole area of the special-shaped tube plate. The two ends of each pressing plate are fixed to the two plates extending out of the lower end of each connecting plate through fasteners. The helium leak detection tool is simple in structure, convenient to disassemble and assemble and capable of being repeatedly used.

Description

Technical Field

[0001] The utility model belongs to the technical field of leak detection of nuclear power equipment, and particularly relates to a helium leak detection device for the weld of the special-shaped tube and tube sheet of a heat exchanger. Background Art

[0002] The PCS heat exchanger is one of the important equipment of the passive containment cooling system (PCS) of a nuclear power plant. Its main function is: the water in the heat exchanger and the high-temperature air in the containment exchange energy through condensation, convection and radiation heat transfer, and then rely on the height difference between the heat exchanger and the external water tank and the density difference caused by the water temperature change to form a natural circulation, so as to continuously transfer the heat in the containment to the outside of the containment. The whole operation process is passive and does not require external intervention.

[0003] Due to the special product structure, the tube sheet of the PCS heat exchanger has a complex shape. The end face of the shell side of the tube sheet is an arc surface, and it is an unclosed shell-side structure, so it is impossible to evacuate the shell side in the conventional way.

[0004] At present, the existing leak detection devices on the market cannot meet the leak detection requirements of this structure. In order to ensure the smooth progress of the helium leak detection test of the tubes and special-shaped tube sheets of the PCS heat exchanger, it is necessary to develop a helium leak detection device for the welds of the special-shaped tube sheets of the PCS heat exchanger tubes. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the problems of the existing technology, and provide a helium leak detection device for the welds of the special-shaped tube sheets of the PCS heat exchanger tubes. The weld area between the tubes and the special-shaped tube sheets is blocked by the leak detection device, the cavity formed by the leak detection device and the tube sheet is evacuated, and helium is sprayed from the back of the tube sheet for helium leak detection.

[0006] In order to solve the technical problems, the technical solution of the utility model is as follows:

[0007] A helium leak detection device for the welds of the special-shaped tube sheets of a heat exchanger, the helium leak detection device includes a sealing cover, pressing plates and connecting plates. The number of the pressing plates and the connecting plates is multiple and equal. Each pressing plate corresponds to one connecting plate. The multiple pressing plates are arranged above the sealing cover and evenly arranged along the length direction of the sealing cover; the sealing cover is a groove body, and the grooved part of the sealing cover is arranged above the entire weld area of the special-shaped tube sheet and is adapted to the size of the entire weld area of the special-shaped tube sheet; a plurality of the connecting plates are arranged below the special-shaped tube sheet, and the shape of the lower part of the special-shaped tube sheet is adapted to the shape of the upper end of the connecting plate. The connecting plates are arranged in the non-tube hole part of the tube hole area of the special-shaped tube sheet;

[0008] Both ends of each pressing plate are fixed on the two plates extending from the lower end of each connecting plate through fasteners.

[0009] Preferably, the width of the connecting plate ≤ the distance between two adjacent tube holes on the left and right.

[0010] Preferably, the sealing cover is a rectangular groove body, and the pressing plate is a cuboid pressing plate.

[0011] Preferably, the connecting plate is in a "convex" shape, the upper end of the connecting plate is arc-shaped, and the arc at the upper end of the connecting plate is adapted to the arc of the special-shaped tube sheet.

[0012] Preferably, an O-ring is also provided in the lower groove of the sealing cover.

[0013] Preferably, lifting rings are also provided on both sides of the outer side of the sealing cover.

[0014] Preferably, a pressure gauge is also provided on the sealing cover.

[0015] Preferably, the fastener includes a nut, a stud, and a washer, and the washer and the nut are sequentially fastened on the stud.

[0016] Preferably, each connecting plate includes a pre-tightening hook, the pre-tightening hook is welded and integrated with one end of the stud close to the connecting plate and fixed inside the connecting plate, and each of the two bottom plates extending from the lower end of each connecting plate is provided with an R-notch, and the pre-tightening hook is embedded at the R-notch.

[0017] Preferably, a gasket is further provided between the upper end of each connecting plate and the special-shaped tube sheet, and the shape of the gasket is the same as the shape of the upper end of the connecting plate.

[0018] Compared with the prior art, the advantages of the present utility model are as follows:

[0019] The present utility model provides a helium leak detection device for the weld of the special-shaped tube sheet of the heat exchanger tubes, including a sealing cover, a pressing plate, and a connecting plate. The weld area between the tubes and the special-shaped tube sheet is blocked by the leak detection device, the cavity formed by the leak detection device and the tube sheet is evacuated, and helium is sprayed from the back of the tube sheet for helium leak detection. The structure is simple, the disassembly and assembly are convenient, it can be reused, the test cost is reduced, the sealing effect is good, and a qualified sealing device is provided for the product sealing. Description of the Drawings

[0020] Figure 1 Side view of a helium leak detection device for the weld of the special-shaped tube sheet of the heat exchanger tubes of the present utility model;

[0021] Figure 2 Front view of the use state of a helium leak detection device for the weld of the special-shaped tube sheet of the heat exchanger tubes of the present utility model;

[0022] Figure 3 Top view of the use state of a helium leak detection device for the weld of the special-shaped tube sheet of the heat exchanger tubes of the present utility model;

[0023] Figure 4, Top view of the sealing cover of a helium leak detection device for the weld of a special-shaped tube sheet of a heat exchanger tube of the present utility model;

[0024] Figure 5 , Tube hole distribution diagram of the special-shaped tube sheet of the weld of the special-shaped tube sheet of a heat exchanger tube of the present utility model;

[0025] Figure 6 , Side view of the special-shaped tube sheet of the weld of the special-shaped tube sheet of a heat exchanger tube of the present utility model.

[0026] Explanation of reference numerals:

[0027] 1, Sealing cover; 2, Pressure plate; 3, Lifting ring; 4, O-ring; 5, Pressure gauge; 6, Washer; 7, Stud; 8, Nut; 9, Pre-tightening hook; 10, Connecting plate; 11, Gasket; 12, Fastener; 13, Tube hole; 14, Special-shaped tube sheet; 15, R-notch; 16, Cavity. Specific embodiments

[0028] The following describes the specific embodiments of the present utility model in conjunction with the embodiments:

[0029] It should be noted that the structures, ratios, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed by the present utility model.

[0030] As Figures 5 - 6 shown, the shell-side end face of the tube sheet of the PCS heat exchanger is an arc surface, and it is an unenclosed shell-side structure. Tube holes 13 are uniformly arranged in two upper and lower rows along the length direction on the special-shaped tube sheet 14.

[0031] Embodiment 1

[0032] As Figures 1 - 4As shown in the figure, a helium leak detection device for the weld of a special-shaped tube sheet of a heat exchanger tube. The helium leak detection device includes a sealing cover 1, pressing plates 2 and connecting plates 10. The number of the pressing plates 2 and the connecting plates 10 is multiple and equal. One connecting plate 10 is correspondingly arranged for each pressing plate 2. The multiple pressing plates 2 are arranged above the sealing cover 1 and evenly arranged along the length direction of the sealing cover 1. The sealing cover 1 is a groove body. The grooved part of the sealing cover 1 is arranged above the entire weld area of the special-shaped tube sheet 14 and is adapted to the size of the entire weld area of the special-shaped tube sheet 14. A plurality of the connecting plates 10 are arranged below the special-shaped tube sheet 14. The shape below the special-shaped tube sheet 14 is adapted to the shape of the upper end of the connecting plate 10. The connecting plate 10 is arranged in the part without the tube holes 13 in the tube hole 13 area of the special-shaped tube sheet 14.

[0033] Both ends of each pressing plate 2 are fixed on two plates extended from the lower end of each connecting plate 10 through fasteners 12.

[0034] Preferably, the width of the connecting plate 10 ≤ the distance between two adjacent tube holes 13 on the left and right.

[0035] The sealing cover is welded with sheet metal into a groove body structure. The sealing surface is grooved and an O-ring is embedded to cover the tube holes in the entire test area.

[0036] Pressing plate, which is used to press the sealing cover. During the test, bolts, nuts and washers are used to make the pressing plate press the sealing cover.

[0037] Embodiment 2

[0038] Preferably, the sealing cover 1 is a rectangular groove body, and the pressing plate 2 is a cuboid pressing plate.

[0039] Preferably, the connecting plate 10 is "convex"-shaped, the upper end of the connecting plate 10 is arc-shaped, and the arc of the upper end of the connecting plate 10 is adapted to the arc of the special-shaped tube sheet 14.

[0040] Preferably, an O-ring 4 is further arranged in the lower groove of the sealing cover 1.

[0041] The O-ring is used in the circumferential groove of the lower sealing surface of the sealing cover to ensure the overall sealing effect of the sealing cover.

[0042] Preferably, lifting rings 3 are further arranged on both sides of the outer side of the sealing cover 1.

[0043] The lifting rings are used to lift the sealing cover.

[0044] Preferably, a pressure gauge 5 is further arranged on the sealing cover 1. During the test, it is connected to the test pressure gauge.

[0045] Preferably, the fastener 12 includes a nut 8, a stud 7 and a washer 6. The washer 6 and the nut 8 are fastened to the stud 7 in sequence. The fastener is used for sealing and pressing tightly. According to the structure after the product tube sheet and the sealing gland are assembled, the fasteners are distributed in the outermost area of the product tube sheet, which is convenient for operation and can ensure the pressing effect.

[0046] Preferably, each connecting plate 10 includes a pre-tightening hook 9. The pre-tightening hook 9 is welded and integrated with one end of the stud 7 close to the connecting plate 10 and fixed inside the connecting plate 10. Each of the two bottom parts extended from the lower end of each connecting plate 10 is provided with an R-notch 15, and the pre-tightening hook 9 is embedded at the R-notch 15.

[0047] The pre-tightening connecting piece is welded and integrated with the stud, which enhances the pre-tightening strength and is convenient for disassembly and assembly.

[0048] Preferably, a gasket 11 is further provided between the upper end of each connecting plate 10 and the special-shaped tube sheet 14. The shape of the gasket is the same as the shape of the upper end of the connecting plate 10.

[0049] The thickness of the connecting plate is determined according to the gap between the tube holes to ensure that the connecting plate can pass through smoothly. The upper end arc surface of the connecting plate is made to be adapted to the arc of the tube sheet according to the arc of the tube sheet, so that the product tube sheet and the helium leak detection device are closely attached when sealed and pressed. Two R-notches are provided at the two bottom parts extended from the connecting plate. During assembly, the pre-tightening hook is embedded at the R-notch to prevent the pre-tightening hook from sliding when pressed.

[0050] The gasket is arranged between the contact surfaces of the tube sheet and the connecting plate to prevent bumps and indentations on the product surface.

[0051] Embodiment 3

[0052] The grooving width of the lower end groove of the sealing gland 1 is equal to the width distance I of the entire weld area above the special-shaped tube sheet 14;

[0053] The pressing plate 2 is arranged above the sealing gland 1. The pressing plate 2 seals the tube holes 13 of the special-shaped tube sheet 14 through the sealing gland 1 and is uniformly arranged along the length direction on the sealing gland 1. The inclination direction of the pressing plate 2 is the same as the tangent direction of two adjacent tube holes 13 of the special-shaped tube sheet 14; the inclination direction of the connecting plate 10 is consistent with the inclination direction of the pressing plate 2.

[0054] The assembly sequence of the present utility model is as follows:

[0055] As Figures 1 - 4As shown in the figure, the utility model discloses a helium leak detection device for the weld of a special-shaped tube sheet of a heat exchanger tube. An O-ring 4 is embedded in the lower groove of the sealing cover 1, and the sealing cover 1 is fixed to the weld area of the product tube sheet by a pressing plate 2. The upper arc surface of the connecting plate 10 is machined according to the arc surface structure of the product tube sheet. The assembly position of the connecting plate 10 needs to avoid the tube hole area. The connecting plate 10 is passed through the middle gap of the tube. The connecting plate 10 is arranged under the arc surface of the tube sheet through a gasket 11. The pressing plate 2 is pressed against the sealing cover 1 by using studs 7, nuts 8 and washers 6 to form an overall helium leak detection device sealing structure.

[0056] The cavity 16 formed by the helium leak detection device and the special-shaped tube sheet 14 is evacuated to 1.33 Pa - 0.133 Pa (10-2 - 10-3 mmHg) continuously, and helium is sprayed along the welds connecting the tubes and the tube sheet one by one from the back of the tube sheet for leak detection. The allowable leakage of a single weld is less than 1.3×10-7 Pa•M3 / s to be qualified.

[0057] This helium leak detection tooling has a simple structure, is convenient to disassemble and assemble and can be reused. The use of the tooling greatly reduces the test cost. Through verification on the first PCS heat exchanger product of "Zhangzhou No. 3 / 4", this helium leak detection tooling has a good sealing effect and provides a qualified sealing device for the product sealing.

[0058] The above has made a detailed description of the preferred implementation mode of the utility model, but the utility model is not limited to the above implementation mode. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can also be made without departing from the purpose of the utility model.

[0059] Many other changes and modifications can be made without departing from the concept and scope of the utility model. It should be understood that the utility model is not limited to a specific implementation mode, and the scope of the utility model is defined by the appended claims.

Claims

1. A helium leak detection device for the weld of a heat exchanger tube with a special shape, characterized in that: The helium leak detection device comprises a sealing cover (1), a pressing plate (2) and a connecting plate (10), wherein the pressing plates (2) and the connecting plates (10) are both multiple and equal in number, and each pressing plate (2) is provided with a corresponding connecting plate (10), and the multiple pressing plates (2) are arranged above the sealing cover (1) and are evenly arranged along the length direction of the sealing cover (1); the sealing cover (1) is a slot body, and the slotted portion of the sealing cover (1) is arranged in the entire weld area above the special-shaped tube sheet (14) and is adapted to the size of the entire weld area of ​​the special-shaped tube sheet (14); the multiple connecting plates (10) are arranged below the special-shaped tube sheet (14), and the shape of the lower part of the special-shaped tube sheet (14) is adapted to the shape of the upper end of the connecting plate (10), and the connecting plate (10) is arranged in the part without the tube hole (13) in the tube hole (13) area of ​​the special-shaped tube sheet (14); Both ends of each pressing plate (2) are fixed to two plates extending from the lower end of each connecting plate (10) via fasteners (12).

2. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The width of the connecting plate (10) is ≤ the distance between two adjacent tube holes (13) on the left and right.

3. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The sealing cover (1) is a rectangular trough body, and the pressing plate (2) is a rectangular pressing plate.

4. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The connecting plate (10) is of a "convex" shape, and the upper end of the connecting plate (10) is arc-shaped, and the arc shape of the upper end of the connecting plate (10) is compatible with the arc shape of the special-shaped tube plate (14).

5. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The groove at the lower end of the sealing cover (1) is also provided with an O-ring (4).

6. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The sealing cover (1) is also provided with lifting rings (3) on both sides of the outer side.

7. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The sealing cover (1) is also provided with a pressure gauge (5).

8. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: The fastener (12) comprises a nut (8), a stud (7) and a washer (6), wherein the washer (6) and the nut (8) are fastened to the stud (7) in sequence.

9. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: Each of the connecting plates (10) comprises a pre-tightening hook (9), which is welded to one end of the stud (7) close to the connecting plate (10) and fixed in the connecting plate (10). The bottom of the two plates extending from the lower end of each of the connecting plates (10) is respectively provided with an R-notch (15), and the pre-tightening hook (9) is embedded in the R-notch (15).

10. A helium leak detection device for special-shaped tube sheet welds of heat exchanger tubes according to claim 1, characterized in that: A gasket (11) is also provided between the upper end of each connecting plate (10) and the special-shaped tube plate (14), and the shape of the gasket is the same as that of the upper end of the connecting plate (10).

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