Overpressure sealing ring and heat exchanger

Abstract

The invention provides an overpressure sealing ring and a heat exchanger, the overpressure sealing ring comprises a nickel-titanium alloy spring, the shape of the section of the nickel-titanium alloy spring in the vertical direction of the heat exchanger comprises an O shape, and the nickel-titanium alloy spring is suitable for being subjected to inward pressure in the radial direction to deform; the first outer layer is arranged around the nickel-titanium alloy spring, and the inner wall of the first outer layer is attached to the outer wall of the nickel-titanium alloy spring; the second outer layer is arranged around the first outer layer, the inner wall of the second outer layer is attached to the outer wall of the first outer layer, and when the nickel-titanium alloy spring deforms, the first outer layer and the second outer layer are suitable for deforming along with the nickel-titanium alloy spring; the outer wall of the second outer layer is in contact with the first mounting flange and the second mounting flange while being deformed, so that at least part of the first space is sealed. A better sealing effect can be achieved, and the equipment stability of the heat exchanger is further guaranteed.

Description

Technical Field

[0001] The present application mainly relates to the technical field of heat exchangers, and in particular to an overpressure sealing ring and a heat exchanger. Background Art

[0002] The normal residual heat removal heat exchanger in a nuclear power plant is one of the main equipment of the normal residual heat removal system (RNS), and is used in domestic CAP1400, AP1000 and other units. The cooling water in the reactor flows through the tube side of the heat exchanger, and the equipment cooling water flows through the shell side. The heat exchanger needs a sealing ring for sealing, and the sealing ring is compressed under certain working conditions to achieve a sealing effect.

[0003] The sealing ring generally includes a coil spring and an enclosure layer. The general material of the coil spring is a metal alloy such as X750, and the material of the enclosure layer is generally silver. Since the heat exchanger will work under overpressure conditions, the compression deformation of the coil spring material used in the prior art cannot meet the downward rebound requirements of overpressure conditions. Since Ag-108 in the silver coating easily absorbs neutrons to form isotope Ag-110, Ag-110 dissolves in cooling water and is radioactive, affecting the performance of the reactor. In addition, the silver coating has a poor fit with the flange surface and is prone to bending and deformation. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide an overpressure sealing ring and a heat exchanger, which can achieve a better sealing effect and further ensure the equipment stability of the heat exchanger.

[0005] To solve the above technical problems, the present application provides an overpressure sealing ring, suitable for a heat exchanger, wherein the heat exchanger comprises a first mounting flange and a second mounting flange, wherein a first space is provided between the first mounting flange and the second mounting flange, and the overpressure sealing ring comprises: a nickel-titanium alloy spring, wherein the cross-sectional shape of the nickel-titanium alloy spring along the vertical direction of the heat exchanger comprises an O-shape, and the nickel-titanium alloy spring is suitable for being deformed by radially inward pressure; a first outer layer, arranged around the nickel-titanium alloy spring, wherein the inner wall of the first outer layer is in contact with the outer wall of the nickel-titanium alloy spring; and a second outer layer, arranged around the first outer layer, wherein the inner wall of the second outer layer is in contact with the outer wall of the first outer layer, wherein when the nickel-titanium alloy spring is deformed, the first outer layer and the second outer layer are suitable for being deformed following the nickel-titanium alloy spring, so that the outer wall of the second outer layer contacts the first mounting flange and the second mounting flange while being deformed, thereby sealing at least part of the first space.

[0006] Optionally, the mass ratio of nickel element to titanium element in the nickel-titanium alloy spring is 0.8-1.

[0007] Optionally, the shapes of the first outer layer and the second outer layer along the vertical cross-section of the heat exchanger include C-type or O-type.

[0008] Optionally, the first outer layer comprises a nickel-chromium-iron based solid solution strengthened alloy, and the second outer layer comprises silver.

[0009] Optionally, the inner diameter of the nickel-titanium alloy spring ranges from 12 mm to 13 mm.

[0010] To solve the above technical problems, the present application provides a heat exchanger, comprising a first mounting flange, a second mounting flange and the overpressure sealing ring as described above, wherein there is a first space between the first mounting flange and the second mounting flange, and the overpressure sealing ring is located in the first space to seal the heat exchanger.

[0011] Optionally, the first mounting flange includes a first surface, the second mounting flange includes a second surface and a third surface perpendicular to a horizontal plane where the second surface is located, the first surface and the second surface are arranged opposite to each other, and the first surface, the second surface and the third surface together constitute the first space.

[0012] Optionally, the first mounting flange includes a first mounting hole, the second mounting flange includes a second mounting hole, and the first mounting hole corresponds to the second mounting hole in spatial position.

[0013] Optionally, the heat exchanger also includes a fastener and a plurality of fastening bolts, the fastener passing through the first mounting hole of the first mounting flange and the second mounting hole of the second mounting flange, the fastening bolt being fixedly connected to the fastener, and the fastening bolt being suitable for pressing the first mounting flange and the second mounting flange.

[0014] Optionally, after the first mounting flange and the second mounting flange are pressed tightly, the overpressure sealing ring fits the first surface, the second surface and the third surface.

[0015] Compared with the prior art, the overpressure sealing ring adopted in the present application uses a nickel-titanium alloy spring to bear pressure, which can significantly increase the compression deformation of the overpressure sealing ring, and can change the mass ratio of nickel and titanium elements in the nickel-titanium alloy spring so that the nickel-titanium alloy spring can change the phase change temperature and mechanical properties, so that the sealing ring can maintain sealing stability under different working conditions, thereby achieving better sealing effect and further ensuring the equipment stability of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0017] Figure 1 is a partial cross-sectional view of a heat exchanger in one embodiment of the present application;

[0018] Figure 2 This is a schematic diagram of the structure of an overpressure sealing ring in one embodiment of the present application;

[0019] Figure 3 It is a compression rebound curve of a sealing ring in a pair of ratios of the present application;

[0020] Figure 4 It is a compression rebound curve of an overpressure sealing ring in one embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0022] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0024] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application 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, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours 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 here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other 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 define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0027] This application refers to Figure 1 A heat exchanger 100 is shown, comprising a first mounting flange 11, a second mounting flange 12 and an overpressure sealing ring 10 proposed in the present application. The first mounting flange 11 comprises a first surface S1, the second mounting flange 12 comprises a second surface S2 and a third surface S3 perpendicular to the horizontal plane where the second surface S2 is located, the first surface S1 is arranged opposite to the second surface S2, and the first surface S1, the second surface S2 and the third surface S3 together constitute a first space A1. The overpressure sealing ring 10 is located in the first space A1 and is suitable for sealing the heat exchanger 100. Exemplarily, the first mounting flange 11 is a pipe flange, and the second mounting flange 12 is a shell flange.

[0028] Further, the first mounting flange 11 includes a first mounting hole 111, and the second mounting flange 12 includes a second mounting hole 222, and the first mounting hole 111 corresponds to the second mounting hole 222 in spatial position. The heat exchanger 100 also includes a fastener 13 and a plurality of fastening bolts 14, the fastener 13 passes through the first mounting hole 111 of the first mounting flange 11 and the second mounting hole 222 of the second mounting flange 12, and the fastening bolts 14 are fixedly connected to the fastener 13, and the fastening bolts 14 are suitable for pressing the first mounting flange 11 and the second mounting flange 12. After the first mounting flange 11 and the second mounting flange 12 are pressed, the overpressure sealing ring 10 is in contact with the first surface S1, the second surface S2 and the third surface S3.

[0029] Reference Figure 2 , Figure 2 The structure of the overpressure sealing ring 10 is shown. Figure 2As shown, the overpressure seal ring 10 includes a nickel-titanium alloy spring 101, a first outer layer 102, and a second outer layer 103. Specifically, the cross-section of the nickel-titanium alloy spring 101 along the vertical direction y of the heat exchanger 100 includes an O-shape, and the nickel-titanium alloy spring 101 is suitable for being deformed by a radially inward pressure. Exemplarily, the inner diameter of the nickel-titanium alloy spring 101 ranges from 12 mm to 13 mm, and the inner diameter of the nickel-titanium alloy spring 101 can be selected according to the working pressure and the preload force of the fastener 13 to meet different working requirements.

[0030] Preferably, the nickel-titanium alloy spring 101 is a superelastic spring with shape memory characteristics, which is characterized in that it is in the austenite phase under high temperature conditions and changes to the martensite phase under low temperature conditions, and can continuously switch between high and low temperature environments, maintain its own resilience, and provide permanent sealing elasticity for the heat exchanger 100. Since there is a process of continuous switching between high and low temperatures inside the heat exchanger 100, and overpressure conditions often occur, the nickel-titanium alloy spring 101 can always maintain the rebound characteristics under various working conditions in the heat exchanger 100, further meeting the sealing requirements in the heat exchanger 100.

[0031] In this embodiment, the mass ratio of nickel and titanium in the nickel-titanium alloy spring 101 is 1, that is, the mass ratios of nickel and titanium in the nickel-titanium alloy spring 101 are 50% and 50%, respectively. In other embodiments of the present application, the mass ratio of nickel and titanium in the nickel-titanium alloy spring 101 can be adjusted according to actual application requirements, and the phase change temperature and mechanical properties of the nickel-titanium alloy spring 101 can be changed to meet different requirements. Specifically, the mass ratio of nickel and titanium in the nickel-titanium alloy spring 101 is in the range of 0.8 to 1, and the mass ratio of nickel and titanium can be arbitrarily selected within this range according to actual requirements, and the present application does not limit this.

[0032] Further, the first outer layer 102 is arranged around the nickel-titanium alloy spring 101, and the inner wall of the first outer layer 102 is in contact with the outer wall of the nickel-titanium alloy spring 101. The second outer layer 103 is arranged around the first outer layer 102, and the inner wall of the second outer layer 103 is in contact with the outer wall of the first outer layer 102, wherein when the nickel-titanium alloy spring 101 is deformed, the first outer layer 1012 and the second outer layer 103 are adapted to deform along with the nickel-titanium alloy spring 101, so that the outer wall of the second outer layer 103 contacts the first mounting flange 11 and the second mounting flange 12 while deforming, thereby sealing part of the first space A1.

[0033] In this embodiment, the cross-section shape of the first outer layer 102 and the second outer layer 103 along the vertical direction y of the heat exchanger 100 is C-shaped. In other embodiments of the present application, the cross-section shape of the first outer layer 102 and the second outer layer 103 along the vertical direction y of the heat exchanger 100 may be O-shaped, and the present application does not limit this. Exemplarily, the first outer layer 102 includes a nickel-chromium-iron based solid solution strengthening alloy, and the second outer layer 103 includes nickel. The first outer layer 102 and the second outer layer 103 can be deformed along with the deformation of the nickel-titanium alloy spring 101.

[0034] In order to better understand the overpressure sealing ring 10, the manufacturing method of the overpressure sealing ring 10 will be briefly introduced. First, the overpressure sealing ring 10 needs to be processed in the austenite phase, and then cooled to make it in the martensite phase. In this way, the overpressure sealing ring 10 will form a memory, that is, when the inside of the heat exchanger 100 is in a high temperature state, the overpressure sealing ring 10 will change to the shape when it was prepared in the austenite phase, and when the inside of the heat exchanger 100 is in a low temperature state, it will change to the shape of the previous martensite phase. After the overpressure sealing ring 10 is prepared, it is placed in the first space A1 between the first mounting flange 11 and the second mounting flange 12, and a load is applied to the first mounting flange 11 and the second mounting flange 12 through the fastener 13 and the fastening bolt 14 to compress and deform them, thereby achieving the effect of sealing the first space A1.

[0035] In order to better understand the performance of the overpressure sealing ring 10, this application refers to Figure 3 A comparative sealing ring compression rebound curve is proposed. Figure 4 The figure shows the compression rebound curve of the overpressure sealing ring 10. The spiral spring used in the sealing ring in the comparative example is an X750 alloy spring.

[0036] First refer to Figure 3 , Figure 3 Curve c is the curve of the X750 alloy spring in the compressed state, and curve d is the curve of the comparative seal ring in the rebound state. The segment ef in curve c is the elastic stage of the X750 alloy spring in the compressed state, and the segment fg in curve c is the plastic stage of the X750 alloy spring in the compressed state. Figure 3 It can be seen that the deformation of the X750 alloy spring increases in the plastic stage, but the change of the clamping load is not large. In the rebound process, when the clamping load is 0, the rebound curve d of the X750 alloy spring does not return to the origin. Compared with before compression, the X750 alloy spring produces a permanent deformation c1 after rebound.

[0037] According to Figure 4It can be seen that curve h is the curve of the nickel-titanium alloy spring 101 in the compressed state, and curve i is the curve of the nickel-titanium alloy spring 101 in the rebound state, wherein the segment jk in the curve h is the elastic stage of the nickel-titanium alloy spring 101 in the compressed state, and the segment km in the curve h is the plastic stage of the nickel-titanium alloy spring 101 in the compressed state. Figure 4 It can be seen that when the pressure load changes slightly, the compression deformation of the nickel-titanium alloy spring 101 changes significantly, and during the rebound process, when the compression load is 0, the rebound curve i of the nickel-titanium alloy spring 101 is compared with that before compression, and the nickel-titanium alloy spring 101 produces a permanent deformation h1 after rebound. It can be clearly seen from the figure that the permanent deformation h1 of the nickel-titanium alloy spring 101 is significantly smaller than the permanent deformation c1 of the X750 alloy spring, and has better resilience.

[0038] The overpressure sealing ring approved in the present application uses a nickel-titanium alloy spring to bear pressure, which can significantly increase the compression deformation of the overpressure sealing ring. The mass ratio of nickel and titanium elements in the nickel-titanium alloy spring can be changed so that the nickel-titanium alloy spring can change the phase change temperature and mechanical properties, so that the sealing ring can maintain sealing stability under different working conditions, thereby achieving a better sealing effect and further ensuring the equipment stability of the heat exchanger.

[0039] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0040] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0041] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more application embodiments, in the above description of the embodiments of this application, multiple features are sometimes merged into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0042] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0043] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. An overpressure sealing ring, suitable for a heat exchanger, the heat exchanger comprising a first mounting flange and a second mounting flange, a first space being provided between the first mounting flange and the second mounting flange, characterized in that: The overpressure sealing ring comprises: A nickel-titanium alloy spring, wherein the cross-section of the nickel-titanium alloy spring along the vertical direction of the heat exchanger includes an O-shape, and the nickel-titanium alloy spring is suitable for being deformed by a radially inward pressure; A first outer layer is disposed around the nickel-titanium alloy spring, wherein an inner wall of the first outer layer is in contact with an outer wall of the nickel-titanium alloy spring; and The second outer layer is arranged around the first outer layer, and the inner wall of the second outer layer is in contact with the outer wall of the first outer layer, wherein when the nickel-titanium alloy spring is deformed, the first outer layer and the second outer layer are suitable for deforming along with the nickel-titanium alloy spring, so that the outer wall of the second outer layer contacts the first mounting flange and the second mounting flange while deforming, thereby sealing at least part of the first space.

2. The overpressure sealing ring according to claim 1, characterized in that: The mass ratio of nickel element to titanium element in the nickel-titanium alloy spring is 0.8-1.

3. The overpressure sealing ring according to claim 1, characterized in that: The shapes of the first outer layer and the second outer layer along the vertical cross section of the heat exchanger include C-shape or O-shape.

4. The overpressure sealing ring according to claim 1, characterized in that: The first outer layer comprises a nickel-chromium-iron based solid solution strengthened alloy and the second outer layer comprises nickel.

5. The overpressure sealing ring according to claim 1, characterized in that: The inner diameter of the nickel-titanium alloy spring is in the range of 12 mm to 13 mm.

6. A heat exchanger, characterized in that: It comprises a first mounting flange, a second mounting flange and the overpressure sealing ring as claimed in claims 1 to 5, a first space is provided between the first mounting flange and the second mounting flange, and the overpressure sealing ring is located in the first space to seal the heat exchanger.

7. The heat exchanger according to claim 6, characterized in that The first mounting flange includes a first surface, the second mounting flange includes a second surface and a third surface perpendicular to a horizontal plane where the second surface is located, the first surface and the second surface are arranged opposite to each other, and the first surface, the second surface and the third surface together constitute the first space.

8. The heat exchanger according to claim 7, characterized in that The first mounting flange includes a first mounting hole, the second mounting flange includes a second mounting hole, and the first mounting hole corresponds to the second mounting hole in spatial position.

9. The heat exchanger according to claim 8, characterized in that It also includes a fastener and a plurality of fastening bolts, wherein the fastener passes through the first mounting hole of the first mounting flange and the second mounting hole of the second mounting flange, and the fastening bolts are fixedly connected to the fastener, and the fastening bolts are suitable for pressing the first mounting flange and the second mounting flange.

10. The heat exchanger according to claim 8, characterized in that When the first mounting flange and the second mounting flange are pressed tightly, the overpressure sealing ring is in contact with the first surface, the second surface and the third surface.

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