Glass-metal sealed electrical penetration assembly and preparation method thereof

Abstract

The invention belongs to the technical field of nuclear reaction safety, and particularly relates to a glass-metal sealed electrical penetration assembly which comprises a barrel assembly provided with a mounting channel in a penetrating mode and a conductor assembly arranged in the mounting channel, and the conductor assembly comprises a wire assembly, a protective sleeve and two sintering assemblies. In the conductor assembly, the two sintering assemblies are arranged at the two ends of the wire assembly, and a first sealing interface is formed during electrical transmission. Then the wire assembly is arranged in the protective sleeve in a penetrating mode, and the two ends of the protective sleeve are connected with the outer sides of the two sintering assemblies in a sealed mode to form a second sealing interface; according to the electrical penetration assembly, the structural form that the three sealing interfaces are arranged at the two ends respectively is adopted, the sealing performance of the pressure boundary under the failure state of any sealing interface at any end can be compensated, and the sealing performance of the pressure boundary under the limiting working condition can be effectively improved; and the risk of radioactive leakage after an accident is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear reaction safety, and in particular relates to a glass-metal sealed electrical penetration component and a preparation method thereof. Background Art

[0002] Electrical penetrations are used on nuclear reactor equipment and are installed on the safety sheath of the reactor. They are special electrical equipment used for cables to pass through the safety sheath. Under normal and various accident conditions, the electrical penetrations should be able to ensure the integrity of the safety sheath, prevent the leakage of radioactive materials, and maintain the continuity of electricity and signals in the safety sheath. Therefore, higher requirements are placed on the sealing environment of the electrical penetrations. The main functional components of the electrical penetrations include the conductor assembly and the cylinder assembly. The conductor assembly runs through the entire cylinder assembly to achieve physical connection of various cables inside and outside the safety sheath. While achieving the electrical connection and signal transmission functions, the conductor assembly and the cylinder assembly jointly achieve the integrity of the safety sheath pressure boundary.

[0003] In the related technology, the conductor assembly is mainly composed of a metal shell, a metal conductor and a sealing material. The selection of the sealing material determines the performance of the conductor assembly of the electrical penetration. Currently, polymer sealing materials are the most widely used in electrical penetrations. However, polymer materials will inevitably experience aging phenomena such as embrittlement and creep during long-term operation and life extension operation. After aging, if a high temperature, high humidity or high radiation accident occurs, there is a risk of losing the sealing and insulation functions.

[0004] Chinese patent application CN115512860A discloses a glass-metal sealed electrical penetration and a preparation method thereof, wherein the glass-metal sealed electrical penetration comprises a metal shell, sealing glass, a metal inner tube, a connecting conductor and a metal solder, wherein the metal inner tube is inserted into the metal shell and is sealed and connected by the sealing glass, and the metal inner tube and the connecting conductor are welded and fixed by the metal solder to improve the firmness and sealing strength of the welding between the metal inner tube and the connecting conductor. As can be seen from the figure, the metal inner tube and the metal shell are completely sealed by the sealing glass. Although the aging problem of polymer materials is solved, the metal inner tube needs to be transferred and welded by the connecting conductor to be sealed with the sealing glass, and the connecting conductor is oxygen-free copper or iron-based material coated with copper alloy. The electrical penetration has higher requirements on whether the sealing technology of the corresponding material of the connecting conductor and the glass is mature and stable on the basis of adding one more solder welding process. The multiple processes and high sealing requirements make it also highly challenging to prevent the leakage of radioactive substances. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a glass-to-metal sealed electrical penetration, aiming to achieve the technical problem of poor electrical contact or leakage of radioactive substances caused by sealing failure.

[0006] In order to achieve the above-mentioned purpose, the present invention proposes a glass-to-metal sealed electrical penetration, including a barrel assembly with an installation channel and a conductor assembly arranged in the installation channel, the conductor assembly includes a wire assembly, a protective sleeve and two sintered assemblies, the two sintered assemblies are arranged at both ends of the wire assembly, the wire assembly is passed through the protective sleeve and the two ends of the protective sleeve are respectively sealed and connected to the outer sides of the two sintered assemblies.

[0007] Optionally, the sintered assembly includes a metal shell, a sealing structure and a metal pin, the metal shell is provided with a through multi-diameter cavity, the sealing structure is sleeved on the metal pin and the two are inserted into the multi-diameter cavity, both ends of the metal pin extend out of the multi-diameter cavity, the sealing structure includes sealing glass, a rubber pad and a sealing glue arranged in sequence in the multi-diameter cavity, and the sealing glass is arranged adjacent to the wire assembly.

[0008] Optionally, the multi-path cavity comprises a sealing cavity, a waterproof cavity and a blocking cavity for respectively accommodating the sealing glass, the glue pad and the sealing glue, and the cavity diameter of the waterproof cavity is larger than the cavity diameters of the sealing cavity and the blocking cavity.

[0009] Optionally, the waterproof cavity is a variable diameter cavity, and the cavity diameter of at least a portion of the waterproof cavity adjacent to the blocking cavity decreases successively.

[0010] Optionally, the rubber pad is made of silicone material, rubber material or silicone rubber material; and / or the sealing glue is epoxy glue.

[0011] Optionally, connecting platforms are provided at outer edges of the ends of the two sintered assemblies facing each other, and both ends of the protective sleeve are respectively sealed and connected to the connecting platforms to encapsulate the wire assembly in the hollow cavity of the protective sleeve.

[0012] Optionally, the protective sleeve is a precision seamless tube made of stainless steel.

[0013] Optionally, the wire assembly includes a wire, at least one support member sleeved on the wire, and two adapters arranged at both ends of the wire, and the two adapters are respectively screwed with two of the sintering components and electrically connected.

[0014] Optionally, the support member is made of insulating material.

[0015] The present invention also provides a method for preparing the glass-to-metal sealed electrical penetration member, the preparation steps comprising:

[0016] (1) Assembling and positioning the sleeve of the sealing glass and the metal pin in the metal housing, and sintering and sealing the assembled structure to obtain a sintered assembly located at one end of the wire assembly;

[0017] (2) repeating step (1) to obtain a sintered assembly at the other end of the wire assembly;

[0018] (3) at least one support member is placed on the conductor, and the insulation layers of both ends of the conductor are stripped off and then crimped with the adapter;

[0019] (4) inserting the wire assembly obtained in step (3) into the hollow cavity of the protective sleeve, first detachably screwing the adapter at one end of the wire assembly to the metal pin of a sintered assembly obtained in step (1), and then laser welding the protective sleeve at the same side end to the metal shell of the sintered assembly; detachably screwing the adapter at the other end of the wire assembly to the metal pin of another sintered assembly obtained in step (1), and then laser welding the protective sleeve at the side end to the metal shell of the sintered assembly;

[0020] (5) The conductor assembly obtained in step (4) is sealed and installed in the installation channel of the cylinder assembly.

[0021] The glass-metal sealed electrical penetration of the present invention comprises a barrel assembly having an installation channel and a conductor assembly arranged in the installation channel, wherein the conductor assembly comprises a wire assembly, a protective sleeve and two sintered assemblies, wherein the two sintered assemblies are arranged at both ends of the wire assembly, and the wire assembly is inserted into the protective sleeve and the two ends of the protective sleeve are respectively sealed and connected to the outer sides of the two sintered assemblies. In the conductor assembly, the wire assembly is connected by the sintered assembly to form a first sealing interface while transmitting electricity, and then the second sealing interface is formed by connecting the two ends of the protective sleeve with the two sintered assemblies, and finally the entire conductor assembly is sealed and connected to the barrel assembly to form a third sealing interface. The electrical penetration adopts the structural form of the above-mentioned three sealing interfaces at both ends to compensate for the sealing performance of the pressure boundary under the failure state of any sealing interface at any end, and can effectively improve the sealing performance of the pressure boundary under extreme working conditions, greatly reducing the risk of radioactive leakage after an accident. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall cross-sectional structure of the conductor assembly of an embodiment of the glass-to-metal sealed electrical penetration of the present invention.

[0023] Figure 2 The cross-sectional structure diagram of a sintered assembly of an embodiment of a glass-to-metal sealed electrical penetration of the present invention.

[0024] Figure 3 It is a schematic structural diagram of a wire assembly of an embodiment of a glass-to-metal sealed electrical penetration of the present invention.

[0025] Figure 4 It is a schematic structural diagram of an adapter according to an embodiment of a glass-to-metal sealed electrical penetration member of the present invention.

[0026] In the figure: 100, glass-metal sealed electrical penetration; 10, conductor assembly; 20, wire assembly; 21, wire; 22, support; 23, adapter; 23A, crimping cavity; 231, crimping section; 232, twisting section; 25, polyimide tape; 30, protective sleeve; 30A, hollow cavity; 40, sintering assembly; 50, metal shell; 50A, multi-diameter hole cavity; 51A, sealed cavity; 52A, waterproof cavity; 53A, plugging cavity; 50B, connecting platform; 50C, snap-in groove; 60, sealing structure; 61, sealing glass; 70, metal pin; 70A, external cavity; 70B, internal cavity. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer and more understandable, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0028] In the related technology, the wire assembly of the electrical penetration is mainly composed of a metal shell, a metal conductor and a sealing material. The selection of the sealing material determines the performance of the wire assembly of the electrical penetration. Currently, polymer sealing materials are the most widely used in electrical penetrations. However, polymer materials will inevitably experience aging phenomena such as embrittlement and creep during long-term operation and life extension operation. After aging, if a high temperature, high humidity or high radiation accident occurs, there is a risk of losing the sealing and insulation functions.

[0029] Chinese patent application CN115512860A discloses a glass-metal sealed electrical penetration and a preparation method thereof, wherein the glass-metal sealed electrical penetration comprises a metal shell, sealing glass, a metal inner tube, a connecting conductor and a metal solder, wherein the metal inner tube is inserted into the metal shell and is sealed and connected by the sealing glass, and the metal inner tube and the connecting conductor are welded and fixed by the metal solder to improve the firmness and sealing strength of the welding between the metal inner tube and the connecting conductor. As can be seen from the figure, the metal inner tube and the metal shell are completely sealed by the sealing glass. Although the aging problem of polymer materials is solved, the metal inner tube needs to be transferred and welded by the connecting conductor to be sealed with the sealing glass, and the connecting conductor is oxygen-free copper or iron-based material coated with copper alloy. The electrical penetration has higher requirements on whether the sealing technology of the corresponding material of the connecting conductor and the glass is mature and stable on the basis of adding one more solder welding process. The multiple processes and high sealing requirements make it also highly challenging to prevent the leakage of radioactive substances.

[0030] In order to achieve the above object, the present invention provides a glass-to-metal sealed electrical penetration 100, comprising a barrel assembly (not shown) having an installation passage therethrough and a conductor assembly 10 disposed in the installation passage, such as Figures 1 to 4As shown, the conductor assembly 10 includes a wire assembly 20, a protective sleeve 30 and two sintered assemblies 40. The two sintered assemblies 40 are arranged at both ends of the wire assembly 20. The wire assembly 20 is inserted into the protective sleeve 30 and the two ends of the protective sleeve 30 are respectively sealed and connected to the outer sides of the two sintered assemblies 40.

[0031] The glass-to-metal sealed electrical penetration 100 of the present invention comprises a barrel assembly having an installation channel therethrough and a conductor assembly 10 disposed in the installation channel. The conductor assembly 10 comprises a wire assembly 20, a protective sleeve 30 and two sintered assemblies 40. The two sintered assemblies 40 are disposed at both ends of the wire assembly 20. The wire assembly 20 is inserted into the protective sleeve 30 and both ends of the protective sleeve 30 are respectively sealed and connected to the outer sides of the two sintered assemblies 40. In the conductor assembly 10, the wire assembly 20 is connected by the sintered assembly 40 to form a first sealing interface while transmitting electricity. Then, a second sealing interface is formed by connecting both ends of the protective sleeve 30 with the two sintered assemblies 40. Finally, the entire conductor assembly 10 is sealed and connected to the barrel assembly to form a third sealing interface. The above-mentioned glass-to-metal sealed electrical penetration 100 penetrates the safety sheath of the nuclear reactor equipment, one end of which is located inside the safety sheath and can contact the radioactive material, and the other end is located outside the safety sheath. The electrical penetration 100 adopts the above-mentioned 1 The structural form of arranging three sealing interfaces at both ends can compensate for the sealing performance of the pressure boundary when any sealing interface at any end fails, and can effectively improve the sealing performance of the pressure boundary under extreme working conditions, greatly reducing the risk of radioactive leakage after an accident.

[0032] Exemplarily, when one or more seals of the first sealing interface, the second sealing interface and the third sealing interface located at one end inside the safety sheath fail, the first sealing interface, the second sealing interface and the third sealing interface located at one end outside the safety sheath all have a sealing and restraining effect on the leakage of radioactive materials.

[0033] Among them, the following sealing structure 60, namely the first sealing interface, can be sealed in the axial direction of the protective sleeve 30 to prevent leakage; the protective sleeve 30, namely the second sealing interface, can prevent the internal material of the cavity from leaking along the connection between the protective sleeve 30 and the sintered component 40, and the connection between the two is laser welding with better leakage prevention performance; the conductor component 10 can prevent the internal material of the cylinder component from leaking through the mechanical sleeve of the protective sleeve 30 and the cylinder component, namely the second sealing interface, and the installation method of the mechanical sleeve also has strong sealing performance, so that the glass-metal sealed electrical penetration 100 has double-end sealing insurance, the sealing effect is greatly improved, and the electrical transmission function is stable.

[0034] Optionally, combined Figure 1 and Figure 2As shown, the sintered component 40 includes a metal shell 50, a sealing structure 60 and a metal pin 70. The metal shell 50 is provided with a through multi-diameter cavity 50A. The sealing structure 60 is sleeved on the metal pin 70 and the two are penetrated in the multi-diameter cavity 50A. Both ends of the metal pin 70 extend out of the multi-diameter cavity 50A. The sealing structure 60 includes a sealing glass 61, a rubber pad and a sealing glue arranged in sequence in the multi-diameter cavity 50A. The sealing glass 61 is arranged adjacent to the wire component 20.

[0035] In this embodiment, the sealing glass 61, the rubber pad and the sealing glue are arranged in sequence in the multi-path cavity 50A. The sealing glass 61 is arranged adjacent to the wire assembly 20 to seal the end of the metal pin 70 connected to the wire assembly 20. The rubber pad is arranged close to the sealing glass 61 to provide waterproof and sealing, so as to prevent water from entering the protective sleeve 30 and affecting the electrical connection between the metal pin 70 and the wire assembly 20. The sealing glue is located at the outermost end to encapsulate the multi-path cavity 50A, thereby improving the sealing and waterproof effects of the sealing glass 61 and the rubber pad.

[0036] Most of the sealing materials for electrical penetrations currently used are made of polymer materials for sealing. However, organic materials are prone to aging phenomena such as embrittlement and creep during long-term operation and life-extended operation, and there is a risk of losing sealing and insulation functions.

[0037] Then, the metal shell 50 may be made of 304 stainless steel, 316L stainless steel, or other nickel-based alloy materials.

[0038] As for the sealing material, an inorganic sealing glass 61 material may be used to replace the original organic polymer material. For example, an insulating high-tensile silicon sealing glass 61 may be used.

[0039] As for the metal pin 70, since the thermal expansion coefficient of the copper conductor is quite different from that of the sealing glass 61 material, there is no mature copper sealing technology with the sealing glass 61 at present, so the mature sealing glass 61 sealing Kovar alloy technology is selected. For example, the sintered assembly 40 of the present invention uses the metal pin 70 of Kovar alloy to form the first sealing interface with the sealing glass 61 to ensure the high requirements of the airtight performance of the glass-metal sealed electrical penetration 100. Specifically, the metal pin 70 is 4J50 glass sealing alloy, 4J29 Kovar alloy or other sealing alloy.

[0040] However, since the electrical conductivity of Kovar alloy is far inferior to that of copper conductors, and the contact resistance between the metal pin 70 and the wire assembly 20 during the actual connection process is affected by factors such as the contact method, contact area, and contact surface roughness, the excessive heat generated by the conductor when a large current is passed is not conducive to long-term stable operation.

[0041] Under the condition that the size of the cylinder assembly (including the cylinder, end plate, junction box and other structures) of the original penetration piece remains unchanged and the old unit can be upgraded and reconstructed, the two ends of the metal pin 70 are respectively provided with an unconnected external connection cavity 70A and an internal connection cavity 70B, one end of the internal connection cavity 70B is connected to the wire assembly 20, and one end of the external connection cavity 70A is used for external wiring. The depth of the internal connection cavity 70B and the external connection cavity 70A should be slightly longer than the length of the connector for connection on the wire assembly 20. Furthermore, the side of the internal connection cavity 70B and the external connection cavity 70A close to each other is set as an arc-shaped convex cavity wall, which can effectively shorten the actual flow length of the Kovar alloy, and greatly reduce the contact resistance, solving the problem of excessive heat generation of the Kovar alloy when passing a large current.

[0042] The sintered assembly 40 uses glass-metal sealing instead of organic material sealing, which has a longer service life, improves the sealing performance of the pressure boundary under extreme working conditions, and reduces the risk of radioactive leakage in accidents and after accidents. At the same time, the electrical penetration prepared by using this structure solves the electrical performance defects of Kovar alloy as a conductor, such as large current and excessive resistance, and fully realizes the transition from organic to inorganic sealing materials.

[0043] Optionally, the multi-path cavity 50A includes a sealing cavity 51A, a waterproof cavity 52A and a blocking cavity 53A for respectively accommodating the sealing glass 61, the rubber pad and the sealing glue, and the cavity diameter of the waterproof cavity 52A is larger than the cavity diameters of the sealing cavity 51A and the blocking cavity 53A.

[0044] In this embodiment, the sealing glass 61 is located in the sealing cavity 51A and is disposed adjacent to the waterproof cavity 52A. The size of the sealing glass 61 does not need to occupy the entire space of the sealing cavity 51A, and can achieve the sealing of the metal pin 70 and the metal shell 50 in the radial direction. The cavity diameter of the waterproof cavity 52A is larger than the cavity diameter of the sealing cavity 51A and the blocking cavity 53A, which can effectively and orderly space the sealing glass 61, the rubber pad and the sealing glue, so that the sealing glass 61 and the sealing glue do not occupy each other's space, thereby improving the sealing efficiency.

[0045] Optionally, the waterproof cavity 52A is a variable diameter cavity, and the cavity diameter of at least a portion of the waterproof cavity 52A adjacent to the blocking cavity 53A decreases successively.

[0046] Optionally, the rubber pad is made of silicone rubber, fluororubber or silicone rubber; and / or the sealing glue is epoxy glue.

[0047] In this embodiment, the rubber pad is made of a flexible silicone material, rubber material or silicone rubber material, so that the rubber pad can enter the variable diameter cavity through the smaller cavity diameter blocking cavity 53A, and then expand in the variable diameter cavity to adapt to the larger cavity diameter variable diameter cavity, thereby effectively blocking and waterproofing one side of the sealing glass 61. The sealing glue is epoxy glue, which is tightly matched with the rubber pad metal pin 70 and the metal shell 50 after solidification to improve the sealing effect.

[0048] Optionally, the outer edges of the two facing ends of the two sintered assemblies 40 are both provided with connecting platforms 50B, and both ends of the protection sleeve 30 are respectively sealed and connected to the connecting platforms 50B to encapsulate the wire assembly 20 in the hollow cavity 30A of the protection sleeve 30 .

[0049] In this embodiment, the outer diameter of one end of the metal shell 50 connected to the protective sleeve 30 is equal to the outer diameter of the protective sleeve 30. The connection platform 50B of each sintered assembly 40 is arranged on the outer end surface of the metal shell 50, and a step is formed on the outer end surface to match the thickness of the protective sleeve 30. The end of the protective sleeve 30 overlaps the step-shaped connection platform 50B, and the outer surface of the protective sleeve 30 is flush with the outer surface of the metal shell 50 and has a smooth transition. The two ends of the protective sleeve 30 are respectively sealed to the connection platforms 50B of the two metal shells 50 to encapsulate the wire assembly 20 in the hollow cavity 30A of the protective sleeve 30, so as to perform secondary sealing on the glass-to-metal sealed electrical penetration 100.

[0050] Furthermore, the outer wall of the metal shell 50 is also provided with a snap-in groove 50C adapted to the external structure, or the outer wall of the metal shell 50 is also provided with a Figure 2 The screw thread 50D adapted to the external structure, the engaging groove 50C or the screw thread 50D is used to fix the sintered component 40 when external power is connected, thereby improving the electrical connection reliability of the external power connection.

[0051] Optionally, the protective sleeve 30 is a precision seamless tube made of stainless steel.

[0052] Optionally, the wire assembly 20 includes a wire 21, at least one support member 22 sleeved on the wire 21, and two adapters 23 provided at both ends of the wire 21, and the two adapters 23 are respectively screwed with two sintering assemblies 40 and electrically connected.

[0053] In this embodiment, the outer layer of the wire 21 is provided with an insulating layer, and the insulated wire 21 is a polyetheretherketone coated multi-strand twisted wire 21. A support 22 is provided on the outer surface in the middle of the wire 21, and the support 22 is fixed to the insulated wire 21 with a polyimide tape 25 to support the wire 21 so that it can swing in the hollow cavity 30A of the protective sleeve 30 to facilitate connection with the metal pin 70 but will not swing significantly to affect the electrical contact effect. An adapter 23 is provided at each end of the insulated wire 21, and the entire wire 21 passes through the protective sleeve 30, and the length of the wire 21 is slightly less than the length of the protective sleeve 30. The insulation layer at both ends of the insulated wire 21 is stripped with wire strippers, and a sealing glass 61 sintering assembly 40 is connected to each of the two adapters 23, and the metal shell 50 of the sintering assembly 40 is welded and sealed with the end face of the protective sleeve 30.

[0054] Furthermore, the adapter 23 is made of copper or other copper alloy materials, such as Figure 3 Combination Figure 4 As shown, the adapter 23 includes a crimping section 231 and a screwing section 232. The end of the crimping section 231 is provided with a crimping cavity 23A. The crimping cavity 23A is a blind hole in the crimping section 231. The blind hole is used to crimp and connect with the wiring conductor after the insulation layer of the insulated wire 21 is stripped. More specifically, the inner connection cavity 70B and the outer connection cavity 70A at both ends of the metal pin 70 are both set as threaded blind holes. One end of the screwing section 232 on the adapter 23 is set as a stud structure. The hole depth of the threaded blind hole of the metal pin 70 should be slightly longer than the effective thread length of the stud structure on the adapter 23. The transfer thread of the stud structure is a fine pitch thread, which is conducive to reducing the contact resistance of the electrical connection through the metal pin 70, and can also reduce and adaptively adjust the matching clearance between the end faces of the metal shell 50 and the protective sleeve 30, so as to facilitate welding of the metal shell 50 and the protective sleeve 30.

[0055] Optionally, the support member 22 is made of insulating material. The number of the support members 22 is adapted and set according to the length of the wire 21, and is not limited here.

[0056] In this embodiment, the support member 22 is a radiation-resistant insulating material such as polyetheretherketone and polysulfone. The support member 22 is arranged in a ring shape. The inner diameter of the support member 22 is slightly larger than the diameter of the wire 21, and the outer diameter is slightly smaller than the inner diameter of the hollow cavity 30A of the protective sleeve 30. By way of example, one of the inner ring side and the outer ring side of the support member 22 can contact the outer peripheral insulation layer of the wire 21 or the inner cavity wall of the hollow cavity 30A of the protective sleeve 30 to ensure that the wire 21 can swing in the hollow cavity 30A of the protective sleeve 30 but will not swing randomly and drastically to affect the electrical contact effect.

[0057] The present invention also provides a method for preparing the glass-to-metal sealed electrical penetration 100, firstly, the metal shell 50 and the Kovar metal pin 70 with a threaded blind hole are sealed with the glass 61 to form a metal seal, and then the wiring is performed through a threaded conversion, and finally the protective sleeve 30 and the metal shell 50 are airtightly welded by laser welding. The structure is simple, and it has good electrical performance while having high sealing performance, high temperature resistance, aging resistance and high stability.

[0058] The specific preparation steps include:

[0059] (1) Assemble and position the sleeve of the sealing glass 61 and the metal pin 70 in the metal housing 50, and sinter and seal the assembled structure to obtain a sintered assembly 40 located at one end of the wire assembly 20.

[0060] Specifically, the metal shell 50 and the metal pin 70 of Kovar alloy obtained by machining are first ultrasonically cleaned and dried, and then the cleaned and dried metal pin 70 is placed in an atmosphere furnace for pre-oxidation treatment, and then the original powder of the sealing glass 61 is melted, ball-milled, pulped, granulated, pressed, debonded and vitrified to obtain a glass blank. The sealing temperature of the sealing glass 61 is between 920-1040°C, and its expansion coefficient is close to that of the metal pin 70 of Kovar metal. Finally, the metal shell 50, the metal pin 70 and the sealing glass 61 blank are positioned with a graphite mold and placed in an atmosphere sintering furnace for sealing. In this process, the sealing glass 61 insulator in a molten state will react with the oxide layer on the metal shell 50 and the metal pin 70 to form an interface layer between the two. After the sealing glass 61 insulator is cooled and solidified, the metal shell and the pin are tightly bonded together, thereby obtaining the above-mentioned sintered component 40 of glass-metal.

[0061] (2) Repeat step (1) to obtain a sintered assembly 40 located at the other end of the wire assembly 20. The structures of the two sintered assemblies 40 are symmetrical.

[0062] Furthermore, the sintered component 40 is surface treated with an acid wash solution to remove the surface oxide scale of the metal shell 50 and the metal pin 70. In this process, the graphite remaining on the surface of the sealing glass 61 can be removed at the same time to prevent gold leakage from the metal shell 50 and the pin and gold deposition on the surface of the sealing glass 61 in the subsequent electroplating process.

[0063] The metal pins 70 of the cleaned and dried sintered assembly 40 are electroplated, and a nickel layer of 2 to 3 um and a gold layer of 0.5 to 1.27 um are plated on the surface of the metal pins 70 of the Kovar alloy in turn to enhance the conductivity and corrosion resistance of the Kovar alloy.

[0064] (3) at least one support member 22 is sleeved on the wire 21, and the two ends of the wire 21 are respectively stripped of the insulation layer and crimped with the adapter 23;

[0065] Specifically, the wiring method inside the wire assembly 20 is as follows: first, the cable of the multi-strand insulated wire 21 is cut to a designed length with wire cutters, and the insulating coating at both ends of the wire 21 is further stripped with wire strippers, so that the wire core is exposed for a certain length, and the length is controlled to be slightly larger than the blind hole depth of the crimping cavity 23A of the adapter 23. At the same time, several insulating support rings are fixed to the wire 21 with polyimide tape 25 to ensure that the wire 21 does not shake in the protective sleeve 30, and the exposed wire core is inserted into the crimping cavity 23A of the adapter 23, and crimped with hydraulic pliers.

[0066] (4) The wire assembly 20 obtained in step (3) is inserted into the hollow cavity 30A of the protective sleeve 30, and the adapter 23 at one end of the wire assembly 20 is first detachably screwed with the metal pin 70 of a sintered assembly 40 obtained in step (1), and then the protective sleeve 30 at the same side end is laser welded with the metal shell 50 of the sintered assembly 40; the adapter 23 at the other end of the wire assembly 20 is detachably screwed with the metal pin 70 of another sintered assembly 40 obtained in step (1), and then the protective sleeve 30 at the side end is laser welded with the metal shell 50 of the sintered assembly 40.

[0067] Specifically, the crimped wire 21, several support members 22 and two adapters 23 are passed through the insulating protective sleeve 30. Finally, the threaded hole of the inner cavity 70B of the metal pin 70 on the sealing glass 61 sintered assembly 40 is aligned with the stud structure on the adapter 23 and then slowly tightened, and the screwing depth of the thread is controlled until the metal shells 50 at both ends are tightly matched with the two end faces of the protective sleeve 30, preferably the matching clearance between the metal shell 50 and the end face of the protective sleeve 30 is ≤0.1mm. After that, the assembled wire assembly 20 is fixed with a clamp, and the matching surface of the metal shell 50 and the end face of the protective sleeve 30 is welded and sealed, and the weld pool depth is 1-2mm.

[0068] (5) Sealing and installing the conductor assembly 10 obtained in step (4) in the installation channel of the cylinder assembly. The glass-to-metal sealed electrical penetration 100 obtained by the above preparation method has three sealing interfaces at both ends. The three sealing interfaces at both ends can compensate for the sealing performance of the pressure boundary in the state of sealing failure of any sealing interface at either end, and can effectively improve the sealing performance of the pressure boundary under extreme working conditions, greatly reducing the risk of radioactive leakage after an accident.

[0069] In a specific implementation process, the protective sleeve 30 is 1.6m long, 20-50mm in diameter, and 4-8mm in wall thickness. The cross-sectional area of ​​the wire 21 is 254mm2. The inner diameter of the sealed cavity 51A of the metal shell 50 is 33mm. The outer diameter of the metal pin 70 is 24mm in diameter. The thickness of the sealing glass 61 in the pre-pressed and pre-heated blank is 5mm. After sintering, it can fill the radial gap between the metal pin 70 and the metal shell 50 in the sealed cavity 51A. It should be noted that the present invention does not limit the size of any structure exclusively, and it can be set as needed.

[0070] Furthermore, Table 1 shows the electrical performance test results of the glass-to-metal sealed electrical penetration 100 in the embodiment.

[0071] Table 1

[0072]

[0073] The rated continuous current stable temperature rise test and the short-circuit heat capacity test were carried out for the above embodiment, and the test parameters were: rated continuous current: 300A; short-circuit current: 24kA / 0.3s; peak value: 50kA.

[0074] Table 2 shows the temperature rise data after the test and the leakage rate test. The test temperature point is the metal pin 70 of the Kovar alloy.

[0075] Table 2

[0076]

[0077]

[0078] It can be seen from Table 1 and Table 2 that the glass-to-metal sealed electrical penetrations 100 prepared in the above manner all have good insulation, sealing, high voltage resistance, and good power-carrying capacity, and still have extremely high sealing performance after undergoing a short-circuit destruction test, which fully meets the technical indicators of nuclear power penetrations.

[0079] In the present invention, if the terms "inside", "outside", "upper", "lower" and the like appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present application 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, and therefore cannot be understood as a limitation on the present application.

[0080] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "fix", and "connect" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0081] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A glass-to-metal sealed electrical penetration, characterized in that: It includes a barrel assembly with an installation channel and a conductor assembly arranged in the installation channel. The conductor assembly includes a wire assembly, a protective sleeve and two sintered assemblies. The two sintered assemblies are arranged at both ends of the wire assembly. The wire assembly is passed through the protective sleeve and the two ends of the protective sleeve are respectively sealed and connected to the outer sides of the two sintered assemblies.

2. The glass-to-metal sealed electrical penetration according to claim 1, characterized in that: The sintered assembly includes a metal shell, a sealing structure and a metal pin. The metal shell is provided with a through multi-diameter cavity. The sealing structure is sleeved on the metal pin and the two are inserted into the multi-diameter cavity. Both ends of the metal pin extend out of the multi-diameter cavity. The sealing structure includes a sealing glass, a rubber pad and a sealing glue arranged in sequence in the multi-diameter cavity. The sealing glass is arranged adjacent to the wire assembly.

3. The glass-to-metal sealed electrical penetration according to claim 2, characterized in that: The multi-path cavity comprises a sealing cavity, a waterproof cavity and a blocking cavity which respectively accommodate the sealing glass, the rubber pad and the sealing glue, and the cavity diameter of the waterproof cavity is larger than the cavity diameters of the sealing cavity and the blocking cavity.

4. The glass-to-metal sealed electrical penetration according to claim 3, characterized in that: The waterproof cavity is a variable diameter cavity, and the cavity diameter of at least the portion of the waterproof cavity adjacent to the blocking cavity decreases successively.

5. The glass-to-metal sealed electrical penetration according to claim 2, characterized in that: The rubber pad is made of silicone material, rubber material or silicone rubber material; and / or the sealing glue is epoxy glue.

6. The glass-to-metal sealed electrical penetration according to any one of claims 1 to 5, characterized in that: The outer edges of the ends of the two sintered assemblies facing each other are both provided with connecting platforms, and the two ends of the protective sleeve are respectively sealed and connected to the connecting platforms to encapsulate the wire assembly in the hollow cavity of the protective sleeve.

7. The glass-to-metal sealed electrical penetration according to any one of claims 1 to 5, characterized in that: The protective sleeve is a precision seamless tube made of stainless steel.

8. The glass-to-metal sealed electrical penetration according to any one of claims 1 to 5, characterized in that: The wire assembly comprises a wire, at least one support member sleeved on the wire, and two adapters arranged at both ends of the wire. The two adapters are respectively screwed with two sintering assemblies and electrically connected.

9. The glass-to-metal sealed electrical penetration according to claim 8, characterized in that: The supporting member is made of insulating material.

10. A method for preparing a glass-to-metal sealed electrical penetration as claimed in any one of claims 1 to 9, characterized in that: The preparation steps include: (1) Assembling and positioning the sleeve of the sealing glass and the metal pin in the metal housing, and sintering and sealing the assembled structure to obtain a sintered assembly located at one end of the wire assembly; (2) repeating step (1) to obtain a sintered assembly at the other end of the wire assembly; (3) at least one support member is placed on the conductor, and the insulation layers of both ends of the conductor are stripped off and then crimped with the adapter; (4) inserting the wire assembly obtained in step (3) into the hollow cavity of the protective sleeve, first detachably screwing the adapter at one end of the wire assembly to the metal pin of a sintered assembly obtained in step (1), and then laser welding the protective sleeve at the same side end to the metal shell of the sintered assembly; detachably screwing the adapter at the other end of the wire assembly to the metal pin of another sintered assembly obtained in step (1), and then laser welding the protective sleeve at the side end to the metal shell of the sintered assembly; (5) The conductor assembly obtained in step (4) is sealed and installed in the installation channel of the cylinder assembly.

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