Metal composite sealing ring for heat exchanger

Abstract

The invention provides a metal composite sealing ring for a heat exchanger, which comprises a sealing outer ring and a plurality of ribs, and the ribs are arranged in the ring inner area of the sealing outer ring and divide the ring inner area of the sealing outer ring into a plurality of sub-areas; the sealing outer ring comprises a first metal layer, a second metal layer and a third metal layer which are sequentially stacked and sleeved from inside to outside, the first metal layer comprises an elastic component, and the hardness of the third metal layer is 69 HV to 80 HV. According to the metal composite sealing ring for the heat exchanger, the metal hardness of the outer layer of the sealing outer ring is moderate, tiny unevenness and defects of the sealing surface of a flange can be effectively overcome, and a good sealing effect can still be achieved under the condition that the roughness of the sealing surface is poor.

Description

Technical Field

[0001] The invention relates to the technical field of multi-pass heat exchangers for nuclear power, and in particular to a metal composite sealing ring for a heat exchanger. Background Art

[0002] In the prior art, the residual heat removal heat exchanger of a passive nuclear power plant is the core equipment of the reactor core cooling system, which is responsible for removing the core decay heat and plays an important role in the safe operation of the reactor. Usually, the heat exchanger is set with a multi-pass structure, which can improve the fluid flow of the internal medium, increase the circulation area, and improve the heat exchange efficiency.

[0003] The diameter of the sealing structure is about 1700mm, and it can withstand high temperature, high pressure and radiation conditions. Figure 1 As shown in the figure, the internal partition divides the entire device into 5 chambers, namely chamber 1 to chamber 5. During the operation of the equipment, it is necessary to ensure that the medium in each chamber does not leak out, and that the medium does not flow between two adjacent chambers. Therefore, the sealing of the outer ring of the heat exchanger and the sealing between two adjacent chambers not only affect the safe operation of the entire equipment, but also have a certain impact on its heat exchange efficiency.

[0004] At present, the outer layer of the existing sealing structure is made of metallic silver, which increases the activity of Ag-110m, affecting the overhaul period, collective dose and radioactive waste discharge. At the same time, the existing connection technology between the outer ring and the inner rib is full welding, which increases the risk of failure of the sealing outer ring.

[0005] In view of this, the inventor of the present application designed a metal composite sealing ring for a heat exchanger in order to overcome the above technical problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the defect of the prior art that there is a lack of a suitable sealing structure for a heat exchanger, and to provide a metal composite sealing ring for a heat exchanger.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] The present invention provides a metal composite sealing ring for a heat exchanger, which is characterized in that the metal composite sealing ring comprises a sealing outer ring and a plurality of ribs, wherein the ribs are installed in the inner ring area of ​​the sealing outer ring to divide the inner ring area of ​​the sealing outer ring into a plurality of sub-areas; the sealing outer ring comprises a first metal layer, a second metal layer and a third metal layer which are stacked in sequence from the inside to the outside, the first metal layer comprises an elastic component, and the hardness of the third metal layer is 69HV to 80HV.

[0009] According to one or more embodiments of the present invention, the sealing outer ring is mounted on a sealing surface of the heat exchanger, and the roughness of the sealing surface is less than 3.2 μm.

[0010] According to one or more embodiments of the present invention, the elastic component is a spring.

[0011] According to one or more embodiments of the present invention, the material of the third metal layer is pure nickel with a grade of N4 or N6.

[0012] According to one or more embodiments of the present invention, the material of the third metal layer is annealed at a temperature of 700° C. to 800° C.

[0013] According to one or more embodiments of the present invention, the ribs are fixed to the wall surface of the inner region of the sealing outer ring by welding.

[0014] According to one or more embodiments of the present invention, the ribs are connected to the wall surface of the inner ring area of ​​the sealing outer ring through a rivet structure and fixed by welding.

[0015] According to one or more embodiments of the present invention, the wall surface of the inner area of ​​the sealing outer ring is a convex arc surface, and the end of the rib is a concave arc surface. The convex arc surface and the concave arc surface are riveted together to fix the end of the rib to the wall surface of the inner area of ​​the sealing outer ring.

[0016] According to one or more embodiments of the present invention, the fitting clearance between the convex arc surface and the concave arc surface is less than or equal to 0.2 mm.

[0017] According to one or more embodiments of the present invention, the multiple ribs include a first rib, a second rib, a third rib and a fourth rib; the length of the first rib is the same as the diameter length of the inner area of ​​the sealing outer ring, the two ends of the first rib are respectively connected to the wall of the inner area of ​​the sealing outer ring, and the first rib divides the inner area of ​​the sealing outer ring into a first semicircular sub-area and a second semicircular sub-area; the second rib is arranged in the first semicircular sub-area, one end of the second rib is connected to the midpoint of the first rib, and the other end of the second rib is connected to the wall of the first semicircular sub-area; the third rib and the fourth rib are arranged in parallel in the second semicircular sub-area, one end of the third rib and the fourth rib are respectively connected to the first rib, and the other end of the third rib and the fourth rib are respectively connected to the wall of the second semicircular sub-area.

[0018] According to one or more embodiments of the present invention, the second rib, the third rib, the fourth rib and the first rib are connected via a rivet structure and fixed by welding.

[0019] The positive and progressive effects of the present invention are:

[0020] The metal composite sealing ring for heat exchanger of the present invention has at least the following advantages:

[0021] 1. The third metal layer of the sealing outer ring has moderate hardness, which can effectively fill the tiny unevenness and defects on the flange sealing surface, and can still achieve a good sealing effect when the sealing surface roughness is poor.

[0022] Second, the metal composite sealing ring reduces the gap between the parts and improves the heat exchange efficiency.

[0023] 3. The connection surfaces between the ribs and the sealing outer ring and between the ribs are increased, thereby avoiding damage to the sealing layer due to deformation of the sealing ring.

[0024] Fourth, the metal composite sealing ring is an integral structure during the installation process, which greatly shortens the installation time of the sealing ring and effectively reduces the risk of long-term exposure of installation workers to the radiation environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0026] Figure 1 It is a schematic diagram of the sealing structure of a heat exchanger in the prior art.

[0027] Figure 2 It is a schematic structural diagram of a metal composite sealing ring used for a heat exchanger according to the present invention.

[0028] Figure 3 The diagram is a schematic structural diagram of a sealing outer ring in a metal composite sealing ring used for a heat exchanger according to the present invention.

[0029] Figure 4 It is a schematic diagram of the present invention before the ribs in the metal composite sealing ring used for the heat exchanger are connected to the sealing outer ring.

[0030] Figure 5 It is a schematic diagram of the connection between the ribs and the third metal layer in the metal composite sealing ring used for the heat exchanger of the present invention.

[0031] [Reference Signs]

[0032] Sealing outer ring 10

[0033] The first metal layer 11

[0034] The second metal layer 12

[0035] The third metal layer 13

[0036] Rib 20

[0037] The first rib 21

[0038] Second rib 22

[0039] The third rib 23

[0040] Fourth rib 24

[0041] Riveting structure 30

[0042] Welding part 40 DETAILED DESCRIPTION

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0044] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used in all drawings to represent the same or similar parts. In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meaning implied by each term.

[0045] Reference Figure 1 to Figure 5 The present invention provides a metal composite sealing ring for a heat exchanger, the metal composite sealing ring comprising a sealing outer ring 10 and a plurality of ribs 20, the ribs 20 being installed in the inner ring area of ​​the sealing outer ring 10 to divide the inner ring area of ​​the sealing outer ring 10 into a plurality of sub-areas;

[0046] The sealing outer ring 10 includes a first metal layer 11, a second metal layer 12 and a third metal layer 13 which are stacked in sequence from the inside to the outside. The first metal layer 11 includes an elastic component, and the hardness of the third metal layer 13 is 69HV to 80HV.

[0047] Preferably, the structure of the metal composite sealing ring for heat exchanger of the present invention is as follows: Figure 2 As shown, it comprises a sealing outer ring 10 and ribs 20 .

[0048] The present invention provides a metal composite sealing ring for a heat exchanger with high resilience. The metal composite sealing ring is used for sealing the tube side of a normal residual heat discharge heat exchanger in a nuclear power plant, and can ensure that there is no cross-flow between chambers.

[0049] The inventors of the present application discovered that by controlling the hardness of the third metal layer 13 of the sealing outer ring 10 between 69HV and 80HV, it can have better elasticity and compressibility, can adapt to different sealing gaps, and can fill the tiny unevenness and defects on the flange sealing surface, thereby achieving a better sealing effect.

[0050] The sealing outer ring 10 in the hardness range of 69HV to 80HV is neither too hard to increase brittleness nor too soft to lack sufficient strength. Therefore, the metal composite sealing ring for the heat exchanger of the present invention has a certain elasticity, and can produce appropriate deformation to adapt when subjected to a small external impact or a size change during the assembly process. At the same time, the metal composite sealing ring is more convenient to install.

[0051] The hardness in the above range is moderate, which can effectively resist the friction and wear caused by other parts in contact with it during relative movement while ensuring the sealing performance. This hardness range also enables the sealing outer ring 10 to withstand a certain pressure.

[0052] As a preferred embodiment of the metal composite sealing ring for heat exchanger of the present invention, the sealing outer ring 10 is suitable for a sealing surface roughness of less than 3.2 μm.

[0053] According to the sealing properties of similar gaskets, the sealing surface roughness is usually required to be less than 0.8 μm. The present invention only needs a roughness of 3.2 μm to meet the sealing requirements, which reduces the manufacturing cost and processing difficulty and has a wider range of applications.

[0054] According to the microscopic sealing mechanism, the realization of sealing does not completely rely on extremely low roughness. At the microscopic level, when two sealing surfaces are in contact, even if the roughness is slightly higher, if the material or structure itself has good elasticity and filling properties, it can fill the microscopic unevenness of the sealing surface and form an effective seal.

[0055] As a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the elastic component is a spring.

[0056] As a preferred embodiment of the metal composite sealing ring for heat exchanger of the present invention, the material of the third metal layer 13 is pure nickel with a grade of N4 or N6.

[0057] As a preferred embodiment of the metal composite sealing ring for heat exchanger of the present invention, the material of the third metal layer 13 is annealed at a temperature of 700° C. to 800° C.

[0058] Preferably, the structure of the sealing outer ring 10 of the metal composite sealing ring for the heat exchanger of the present invention is as follows: Figure 3As shown, it is designed as a reinforced structure with a spring, wherein the first metal layer 11 is a spring, and a composite bimetallic layer is arranged outside the first metal layer 11, namely, a second metal layer 12 and a third metal layer 13, and the intermediate layer metal serves as a transition layer to play a filling and strengthening role. The metal material of the third metal layer 13 is preferably N4 or N6, and the hardness can be controlled between 69HV and 80HV through high-temperature annealing treatment at 700°C to 800°C. In this hardness range, the tiny unevenness and defects on the flange sealing surface can be filled, thereby achieving a better sealing effect.

[0059] Reference Figure 4-5 As a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the ribs 20 are fixed to the sealing outer ring 10 by welding.

[0060] Reference Figure 4-5 As a preferred embodiment of the metal composite sealing ring for heat exchanger of the present invention, the end of the rib 20 is connected to the inner surface of the sealing outer ring 10 through a rivet structure 30 and fixed by welding.

[0061] Reference Figure 4-5 As a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the wall surface of the inner ring area of ​​the sealing outer ring 10 is a convex arc surface, and the end of the rib 20 is a concave arc surface. The convex arc surface and the concave arc surface are riveted together, so that the end of the rib 20 is fixed to the wall surface of the inner ring area of ​​the sealing outer ring 10.

[0062] Figure 4 FIG. 2 shows an embodiment in which the rivet structure 30 of the rib 20 adopts an end portion of the rib 20 as a concave arc surface.

[0063] It should be noted that, in addition to the cooperative connection between the sealing outer ring 10 and the ribs 20, the ribs can also be connected to each other by the above-mentioned riveting + welding combination connection method.

[0064] As a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the fitting clearance between the convex arc surface and the concave arc surface is less than or equal to 0.2 mm.

[0065] Preferably, in the manufacture of the metal composite sealing ring for the heat exchanger of the present invention, the sealing outer ring 10 and the rib 20 are processed in a separate manner, such as Figure 4 and Figure 5 The connection between the ribs 20 and the connection between the ribs 20 and the sealing outer ring 10 should preferably adopt a combination of "clip riveting + welding" to meet the sealing function requirements during the operation of the equipment.

[0066] like Figure 5As shown, when preparing the metal composite sealing ring for the heat exchanger of the present invention, firstly, a rivet structure 30 is processed at the end of the rib 20 according to the diameter of the sealing ring. After matching with the outer arc surface of the sealing outer ring 10 or the rib 20 to be bonded, the gap is controlled within 0.2 mm, and then the two bonding parts are welded by fusion welding (up and down welding or left and right welding). The figure shows the position of the welding part 40.

[0067] like Figure 2 As shown, as a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the rib 20 includes a first rib 21, a second rib 22, a third rib 23 and a fourth rib 24;

[0068] The length of the first rib 21 is the same as the diameter of the inner area of ​​the sealing outer ring 10, and both ends of the first rib 21 are respectively connected to the wall surface of the inner area of ​​the sealing outer ring 10. The first rib 21 divides the inner area of ​​the sealing outer ring 10 into a first semicircular sub-area and a second semicircular sub-area.

[0069] The second rib 22 is disposed in the first semicircular sub-region, one end of the second rib 22 is connected to the midpoint of the first rib 21, and the other end of the second rib 22 is connected to the wall surface of the first semicircular sub-region.

[0070] The third rib 23 and the fourth rib 24 are arranged in parallel in the second semicircular sub-area, one end of the third rib 23 and the fourth rib 24 are respectively connected to the first rib 21, and the other end of the third rib 23 and the fourth rib 24 are respectively connected to the wall surface of the second semicircular sub-area.

[0071] Preferably, if Figure 2 As shown, the third rib 23 and the fourth rib 24 are at the same distance from the midpoint of the first rib 21, and the distance is L.

[0072] As a preferred embodiment of the metal composite sealing ring for a heat exchanger of the present invention, the second rib 22, the third rib 23, the fourth rib 24 and the first rib 21 are connected by a rivet structure 30 and fixed by welding.

[0073] Preferably, since each rib 20 is cylindrical, the surface of each rib 20 is a convex arc surface, and the end of the rib 20 is set as a concave arc surface, the convex arc surface and the concave arc surface are riveted together to connect the end of the rib 20 and the surface of the rib 20.

[0074] Preferably, the fitting clearance between the convex arc surface and the concave arc surface is within 0.2 mm.

[0075] like Figure 5As shown, when preparing the metal composite sealing ring for the heat exchanger of the present invention, firstly, a rivet structure 30 is processed at the end of the rib 20 according to the diameter of the sealing ring. After matching with the outer arc surface of the sealing outer ring 10 or the rib 20 to be bonded, the gap is controlled within 0.2 mm, and then the two bonding points are welded by fusion welding (up and down welding or left and right welding). The position of the welding part 40 is shown in the figure.

[0076] As a preferred embodiment of the metal composite sealing ring for heat exchanger of the present invention, the resilience of the metal composite sealing ring is above 0.45 mm, and the leakage rate is 1.0×10 -7 Pa.m 3 / s or less.

[0077] The metal composite sealing ring used in the heat exchanger of the present invention can have a resilience of more than 0.45 mm (common sealing rings are usually more than 0.25 mm), and a leakage rate of 1.0×10-7 Pa.m 3 / s or less, and due to the existence of the rivet structure 30 between the ribs and between the ribs and the sealing outer ring, even if the welding falls off, the integrity of the sealing ring can be guaranteed without falling off or separation.

[0078] The metal composite sealing ring for the heat exchanger of the present invention can be used for sealing the multi-pass structure of the heat exchanger, which can prevent the leakage of the heat exchanger fluid and also ensure the sealing requirements between the tube passes of the heat exchanger.

[0079] In summary, the metal composite sealing ring for heat exchangers of the present invention has a wide range of applications, and its connection method reduces the gap between the ribs and the sealing outer ring, and between the ribs. Compared with the prior art, the present invention has the following advantages:

[0080] 1. The third metal layer 13 of the sealing outer ring 10 of the metal composite sealing ring for heat exchanger of the present invention has moderate metal hardness, which can effectively fill the tiny unevenness and defects on the flange sealing surface, and can still achieve a good sealing effect when the sealing surface roughness is poor.

[0081] 2. The metal composite sealing ring used for the heat exchanger of the present invention reduces the gap between the parts and improves the heat exchange efficiency.

[0082] 3. In the present invention, the connection surfaces between the ribs and the sealing outer ring and between the ribs are increased, thereby avoiding damage to the sealing layer due to deformation of the sealing ring.

[0083] Fourth, the metal composite sealing ring used for the heat exchanger of the present invention is an integral structure during the installation process, which greatly shortens the installation time of the sealing ring and effectively reduces the risk of long-term exposure of installation workers to the radiation environment.

[0084] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A metal composite sealing ring for a heat exchanger, characterized in that: The metal composite sealing ring comprises a sealing outer ring and a plurality of ribs, wherein the ribs are installed in the inner ring area of ​​the sealing outer ring to divide the inner ring area of ​​the sealing outer ring into a plurality of sub-areas; The sealing outer ring includes a first metal layer, a second metal layer and a third metal layer stacked in sequence from the inside to the outside, the first metal layer includes an elastic component, and the hardness of the third metal layer is 69HV to 80HV.

2. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The sealing outer ring is mounted on a sealing surface of the heat exchanger, and the roughness of the sealing surface is less than 3.2 μm.

3. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The elastic component is a spring.

4. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The material of the third metal layer is pure nickel with a grade of N4 or N6.

5. The metal composite sealing ring for a heat exchanger according to claim 4, characterized in that: The material of the third metal layer is annealed at a temperature of 700° C. to 800° C.

6. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The ribs are fixed to the wall surface of the inner ring area of ​​the sealing outer ring by welding.

7. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The ribs are connected to the wall surface of the inner ring area of ​​the sealing outer ring through a rivet structure and fixed by welding.

8. The metal composite sealing ring for a heat exchanger according to claim 7, characterized in that: The wall surface of the inner ring area of ​​the sealing outer ring is a convex arc surface, and the end of the rib is a concave arc surface. The convex arc surface and the concave arc surface are riveted together to fix the end of the rib to the wall surface of the inner ring area of ​​the sealing outer ring.

9. The metal composite sealing ring for a heat exchanger according to claim 8, characterized in that: The matching clearance between the convex arc surface and the concave arc surface is less than or equal to 0.2 mm.

10. The metal composite sealing ring for a heat exchanger according to claim 1, characterized in that: The plurality of ribs include a first rib, a second rib, a third rib and a fourth rib; The length of the first rib is the same as the diameter of the inner region of the sealing outer ring, and both ends of the first rib are respectively connected to the wall surface of the inner region of the sealing outer ring, and the first rib divides the inner region of the sealing outer ring into a first semicircular sub-region and a second semicircular sub-region; The second rib is disposed in the first semicircular sub-region, one end of the second rib is connected to the midpoint of the first rib, and the other end of the second rib is connected to the wall surface of the first semicircular sub-region; The third rib and the fourth rib are arranged in parallel in the second semicircular sub-area, one end of the third rib and the fourth rib are respectively connected to the first rib, and the other end of the third rib and the fourth rib are respectively connected to the wall surface of the second semicircular sub-area.

11. The metal composite sealing ring for a heat exchanger according to claim 10, characterized in that: The second rib, the third rib, the fourth rib and the first rib are connected via a rivet structure and fixed by welding.

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