Penetration piece and penetration connection structure for nuclear power station containment

Abstract

The utility model provides a penetration piece and a penetration connecting structure for a nuclear power station containment vessel, the penetration piece comprises a pre-embedded sleeve, a first sealing ring plate, a second sealing ring plate and a sealing head assembly, the pre-embedded sleeve penetrates through and is connected with the containment vessel; the first sealing ring plate is arranged on the embedded sleeve and is connected with the inner side wall of the containment in an attached manner; the second sealing ring plate is arranged on the embedded sleeve and is attached to the outer side wall of the containment; the end socket assembly is arranged at the end part of the pre-embedded sleeve and is positioned outside the containment; according to the penetration piece, the first sealing ring plate and the second sealing ring plate which are mounted on the pre-embedded sleeve in a sleeving manner are attached and blocked on the inner side wall and the outer side wall of the containment, so that a gas leakage path of a gap between the pre-embedded sleeve and the containment is prolonged. And the bulge structure of the first sealing ring plate can effectively and fixedly connect the embedded sleeve into the containment, so that the containment and the penetration piece are sealed, and the connection reliability of the penetration piece is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to nuclear power technology field, concretely relates to a kind of for nuclear power plant containment's through piece and through connection structure. BACKGROUND

[0002] Containment, as the third barrier of nuclear power plant, needs to contain radioactivity in the running state and accident condition, to realize radiation shielding, and reduce the overall leakage rate of containment. The current containment is a structure poured with concrete, which has good sealing effect. However, in the design of traditional large containment, a layer of metal steel plate is laid on the inner wall of the containment to form a steel lining structure in order to further control the leakage rate. The containment mechanical through-piece is a device that penetrates the containment shell wall and seals the opening. It is designed with a special structure for sealing welding between the through-piece and the steel lining.

[0003] However, with the popularity of small reactor containment, the inherent safety of small reactor containment is good, and the source term is extremely low. Therefore, the design of steel lining is cancelled in the design of containment. If the traditional mechanical through-piece structure is used, the sealing welding between the mechanical through-piece and the containment cannot be implemented, and the sealing leakage between the mechanical through-piece and the containment cannot be effectively controlled, resulting in poor sealing effect and reduced reliability. SUMMARY

[0004] In view of the problems existing in the prior art, the utility model provides a through-piece for nuclear power plant containment and a through connection structure to improve the technical problems of poor sealing effect between the mechanical through-piece and the containment and reduced safety and reliability due to the cancellation of the design of steel lining in the existing small reactor containment.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a through-piece for nuclear power plant containment, which comprises a pre-buried sleeve, a first sealing ring plate, a second sealing ring plate and a head assembly. The pre-buried sleeve penetrates and connects the containment. The first sealing ring plate is arranged on the pre-buried sleeve and connected to the inner side wall of the containment. The second sealing ring plate is arranged on the pre-buried sleeve and connected to the outer side wall of the containment. The head assembly is arranged at the end of the pre-buried sleeve and located outside the containment.

[0006] In an embodiment of the utility model, the through-piece further comprises a third sealing ring plate, which is arranged on the pre-buried sleeve and pre-buried and installed on the side wall of the containment.

[0007] In an embodiment of the utility model, a plurality of third sealing ring plates are arranged between the first sealing ring plate and the second sealing ring plate.

[0008] In the first embodiment of the through piece of the utility model, the outer plate face of the first sealing ring plate is flush with the inner side wall of the safety shell; the outer plate face of the second sealing ring plate is flush with the outer side wall of the safety shell.

[0009] In the first embodiment of the through piece of the utility model, the head assembly comprises a connecting sleeve and a head, one end of the connecting sleeve is coaxially connected with the embedded sleeve, and the other end of the connecting sleeve is provided with the head.

[0010] In the first embodiment of the through piece of the utility model, the connecting sleeve is further provided with a heat dissipation plate.

[0011] In the first embodiment of the through piece of the utility model, the head comprises a head part and an inner shell connecting pipe, and the head part and the inner shell connecting pipe are integrally forged.

[0012] The utility model also provides a through connecting structure for a safety shell of a nuclear power plant, which comprises a safety shell and the through piece.

[0013] In the first embodiment of the through connecting structure of the utility model, the through connecting structure further comprises a first sealing layer; the first sealing layer is coated between the first sealing ring plate and the inner side wall of the safety shell.

[0014] In the first embodiment of the through connecting structure of the utility model, the through connecting structure further comprises a second sealing layer; the second sealing layer is coated between the second sealing ring plate and the outer side wall of the safety shell.

[0015] In the through piece and the through structure for a safety shell of a nuclear power plant of the utility model, the through piece is fixed on the first sealing ring plate and the second sealing ring plate of the embedded sleeve, is attached to the inner and outer side walls of the safety shell and is blocked, thereby prolonging the gas leakage path of the gap between the embedded sleeve and the safety shell; the convex structure of the first sealing ring plate can effectively fix and connect the embedded sleeve in the safety shell, realize the sealing of the safety shell and the through piece and increase the reliability of the through piece connection. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other embodiments according to these drawings without creating creative labor.

[0017] Figure 1The utility model discloses a connection structure schematic drawing in one embodiment of the utility model through -going piece.

[0018] Figure 2 The utility model discloses a connection structure schematic drawing of partial steel lining in another embodiment of the utility model through -going piece.

[0019] Figure 3 The utility model discloses a structure schematic drawing in one embodiment of the utility model through -going connection structure.

[0020] Figure 4 The utility model discloses a first sealing layer and its sealing position schematic drawing in one embodiment of the utility model through -going connection structure.

[0021] Element number explanation:

[0022] 100, containment vessel;200, embedded sleeve;300, first sealing ring plate;400, second sealing ring plate;500, head assembly;510, connecting sleeve;520, head;521, head part;522, shell inner connecting pipe;530, heat dissipation plate;600, third sealing ring plate;700, first sealing layer;800, second sealing layer. DETAILED DESCRIPTION

[0023] The following will be described by specific concrete examples, and the person skilled in the art can easily understand other advantages and effects of the utility model from the disclosure of the specification. The utility model can also be implemented or applied by another different specific embodiment, and each detail in the specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the utility model. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the utility model are for describing specific specific embodiments, not for limiting the protection scope of the utility model. The test method not noted specific condition in the following embodiments is usually according to conventional condition, or according to the condition suggested by each manufacturer.

[0024] When the embodiment gives a numerical range, it should be understood that, unless otherwise specified by the utility model, each numerical range can be selected between two endpoints and any one numerical between two endpoints. Unless otherwise defined, all technical and scientific terms used in the utility model and the mastery of the prior art by the person skilled in the art and the description of the utility model can also use any method, equipment and material of the prior art similar or equivalent to the method, equipment and material in the embodiment of the utility model to realize the utility model.

[0025] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0026] See also Figures 1 to 4 In order to address the technical problems of eliminating the steel lining in the containment of a small reactor, poor connection and sealing effects between the mechanical penetration piece and the containment, and reduced safety and reliability, the utility model provides a penetration piece and a penetration connection structure for the containment of a nuclear power plant. The penetration piece of the utility model realizes the sealed installation of the penetration piece and the containment through the design of the first sealing ring plate and the second sealing ring plate, and at the same time extends the gas leakage path of the gap between the embedded casing and the containment, thereby ensuring its reliability and sealing.

[0027] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides, on the one hand, a penetration piece for the containment of a nuclear power plant, which is a component connecting pipes, cables or other channels inside and outside the containment. Its structural design must be able to withstand and act on the containment with a considerable load and load combination, while ensuring good sealing to prevent radioactive substances from leaking to the outside of the containment; the penetration piece includes a pre-buried sleeve 200, a first sealing ring plate 300, a second sealing ring plate 400 and a head assembly 500, wherein the pre-buried sleeve 200 is a pre-buried pipe structure, the pre-buried sleeve 200 penetrates and connects the side wall of the containment 100, one end of which is connected to the inner cavity of the containment 100, and the other end is connected to the inner cavity of the containment 100. One end is outside the containment shell 100, wherein a first sealing ring plate 300 is provided on one side of the embedded sleeve 200. The first sealing ring plate 300 is coaxially arranged on the side of the tube body of the embedded sleeve 200 and is fitted and connected to the inner side wall of the containment shell 100, thereby realizing the installation and sealing between the embedded sleeve 200 and the containment shell 100. At the same time, the first sealing ring plate 300 is pre-buried and connected to the inner side wall of the containment shell 100, thereby extending the gas leakage path and ensuring the sealing effect. At the same time, the first sealing ring plate 300 replaces the steel lining structure connected to the embedded sleeve 200 to realize the welding seal between the embedded sleeve 200 and the first sealing ring plate 300, thereby ensuring its installation reliability. In this embodiment, the first sealing ring plate 300 and the embedded sleeve 200 are welded by sealing welding. The first sealing ring plate 300 and the embedded sleeve 200 are first welded and connected, and then embedded in the civil construction process of the containment shell 100, and at least part of the first sealing ring plate 300 is embedded in the inner wall of the containment shell 100, thereby ensuring the sealing installation effect between the first sealing ring plate 300 and the containment shell 100; in other embodiments, the first sealing ring plate 300 and the containment shell 100 can also be an integral casting structure.

[0028] The second sealing ring plate 400 is arranged on the embedded sleeve 200 and located on the side opposite to the first sealing ring plate 300 and is attached to the outer side wall of the containment vessel 100; the second sealing ring plate 400 has similar functions to the first sealing ring plate 300 and is used to realize the embedded connection between the embedded sleeve 200 and the containment vessel 100 and to lengthen the gas leakage path, thereby ensuring the sealing effect between the penetrating member and the containment vessel 100; in the embodiment, the second sealing ring plate 400 is welded to the embedded sleeve 200 by means of sealing welding; during installation, the second sealing ring plate 400 and the embedded sleeve 200 are welded first and then embedded and installed in the process of civil construction of the containment vessel 100, and at least part of the second sealing ring plate 400 is embedded in the outer side wall of the containment vessel 100, thereby ensuring the sealing effect between the penetrating member on the outer side and the containment vessel 100 and lengthening the gas leakage path; however, in other embodiments, the containment vessel 100 and the second sealing ring plate 400 can also be an integrally cast structure.

[0029] The material of the embedded sleeve 200, the first sealing ring plate 300 and the second sealing ring plate 400 is not limited and can be, for example, high-strength alloy steel, which has sufficient strength and toughness and can resist stress caused by internal pressure or temperature change and corrosion resistance and resist aging and damage caused by radiation.

[0030] The head assembly 500 is arranged at the end of the embedded sleeve 200 and located on the outside of the containment vessel 100 and is used to play a sealing role of the mechanical penetrating member and to ensure the connection between the inside and the outside of the containment vessel 100 and prevent radioactive material from leaking.

[0031] Please refer to Figures 1 to 3 In the embodiment of the utility model, the penetrating member further comprises a third sealing ring plate 600, the third sealing ring plate 600 is arranged on the embedded sleeve 200, the third sealing ring plate 600 is located between the first sealing ring 300 and the second sealing ring 400, and the third sealing ring plate 600 is embedded and installed on the side wall of the containment vessel 100; a sealing ring for lengthening the leakage path is arranged again on the gap between the pipe body of the embedded sleeve 200 and the containment vessel 100, thereby further ensuring the sealing effect between the penetrating member and the containment vessel 100; in the embodiment, the third sealing ring plate 600 has similar structure to the first sealing ring plate 300 or the second sealing ring plate 400 and is coaxially welded to the pipe body of the embedded sleeve 200 by means of sealing welding, thereby blocking and lengthening the gas leakage path; however, in other embodiments, the third sealing ring plate 600 and the embedded sleeve 200 can also be an integrally cast structure; during the process of civil construction of the containment vessel 100, the embedded sleeve 200 with the structures of the first sealing ring plate 300, the second sealing ring plate 400 and the third sealing ring plate 600 is embedded and installed, thereby finally realizing the fixation and sealing between the penetrating member and the containment vessel 100.

[0032] Among them, the first sealing ring plate 300, the second sealing ring plate 400 and the third sealing ring plate 600 have the same working principle for sealing the embedded sleeve 200. Since the embedded sleeve 200 is in a straight tube form, it is sealed with the concrete wall of the containment shell 100 through fitting contact. There must be a very small gap between the embedded sleeve 200 in the straight tube form and the concrete wall of the containment shell 100, and the sealing effect is poor. Therefore, three groups of different sealing ring plates are added at different positions to increase the contact area between the embedded sleeve 200 and the civil structure of the containment shell 100. At the same time, the sealing ring plate is a raised structure compared to the sleeve, which can change the flow direction of the leaked gas multiple times, increasing the flow obstacles, thereby increasing the reliability of the seal. At the same time, in order to further enhance the blocking and sealing effect of the third sealing ring plate 600 between the embedded casing 200 and the containment shell 100, in one embodiment of the penetration piece of the present invention, the number of the third sealing ring plates 600 is not limited to only one, and can be multiple. Multiple third sealing ring plates 600 are embedded in the side wall of the containment shell 100 and are spaced apart between the first sealing ring plate 300 and the second sealing ring plate 400.

[0033] See also Figure 1 and Figure 4 In one embodiment of the penetration member of the present invention, the outer plate surface of the first sealing ring plate 300 is flush with the inner wall of the containment shell 100; specifically, the non-side wall contact surface of the first sealing ring plate 300 and the containment shell 100, that is, the plate surface of the first sealing ring plate 300 close to the inner cavity of the containment shell 100 is flush with the inner wall of the containment shell 100, so that the inner wall of the containment shell 100 and the first sealing ring plate 300 form a nearly integrated planar structure, which can ensure the installation effect of the first sealing ring plate 300 in the inner cavity of the containment shell 100, and at the same time, eliminate the convexity between the outer plate surface of the first sealing ring plate 300 and the inner wall of the containment shell 100. It is convenient to use sealant to seal the gap between the first sealing ring plate 300 and the safety shell 100 in the future, so as to achieve a better sealing effect; similarly, the outer plate surface of the second sealing ring plate 400 is flush with the outer side wall of the safety shell 100, and the outer plate surface of the second sealing ring plate 400 is the plate surface in contact with the air outside the shell. The inner plate surface and the circumferential side surface of the second sealing ring plate 400 are embedded and installed in the safety shell 100, so that there is no bulge between the outer plate surface of the second sealing ring plate 400 and the safety shell 100, which facilitates the subsequent application of sealant between the second sealing ring plate 400 and the outer side wall of the safety shell 100, so as to achieve a better sealing effect.

[0034] See also Figure 1 and Figure 2In the through-piece one embodiment of the utility model, the head assembly 500 includes the connecting sleeve 510 and the head 520, one end of the connecting sleeve 510 is coaxially connected with the embedded sleeve 200, the embedded sleeve 200 is welded with the connecting sleeve 510 through the seal welding at one end outside the safety shell 200, the connecting sleeve 510 is used to lead out part of the heat in the embedded sleeve 200, so as to ensure that the concrete temperature of the safety shell 100 is below the limit temperature, prevents the damage caused by the overheating of the concrete, the other end of the connecting sleeve 510 is installed with the head 520, so as to realize the sealing between the embedded sleeve 200 and the connecting sleeve 510.

[0035] Please refer to Figure 1 In the through-piece one embodiment of the utility model, the connecting sleeve 510 is further provided with the heat dissipation plate 530, the shape of the heat dissipation plate 530 is not limited, which can be any suitable type structure for increasing the contact area between the connecting sleeve 510 and the air outside the shell for heat exchange, for example, the heat dissipation plate 530 is the ring plate structure similar to the seal ring plate structure, the heat dissipation plate 530 is welded on the outside of the connecting sleeve 510, in order to ensure the heat dissipation transmission effect between the heat dissipation plate 530 and the connecting sleeve 510, the heat dissipation plate 530 and the connecting sleeve 510 are preferably welded by the seal welding. Further, the number of the heat dissipation plate 530 on the connecting sleeve 510 is not limited, and the plurality of heat dissipation plates 530 are arranged on the connecting sleeve 510 at intervals.

[0036] Please refer to Figure 2 In the through-piece one embodiment of the utility model, wherein the head 520 includes the head part 521 and the shell inner pipe 522, the head part 521 and the shell inner pipe 522 are integrally forged structures, one end of the shell inner pipe 522 penetrates through the connecting sleeve 510 and the embedded sleeve 200, and the other end penetrates through the head part 521 and is welded and connected with the process pipeline, so as to realize the overall sealing between the through-piece and the safety shell.

[0037] Please refer to Figure 2 In the through-piece one embodiment of the utility model, wherein the first seal ring plate 300 can also adopt the local steel lining, which is different from the steel lining structure of the whole safety shell, and only the steel lining protection is adopted around the through-piece, the sealing is realized by welding the embedded sleeve 200 of the through-piece with the local steel lining, the second seal ring plate 400 and the third seal ring plate 600 are two seal ring plates, which are used for redundant protection. The local steel lining is connected with the embedded sleeve 200 through the seal welding, and there is no need to smear the sealing adhesive layer between the local steel lining and the inner wall of the safety shell 100; when the through-piece structure of the embodiment is constructed, the local steel lining and the civil construction of the safety shell 100 are carried out first, then the connection between the embedded sleeve 200 and the completed local steel lining and the embedding of the embedded sleeve 200 are carried out, compared with the seal ring plate, the construction difficulty is increased.

[0038] Referring to Figure 3 The utility model discloses another aspect still provides a kind of for nuclear power plant containment through connection structure, which includes containment 100 and the through piece described in any of the above embodiments;Wherein containment 100 is civil concrete structure, inside is not set up steel lining, through piece is embedded and installed in the lateral wall of containment, and it is through the lateral wall of containment 100;Specifically, the through piece at least includes embedded sleeve 200, first sealing ring plate 300, second sealing ring plate 400 and head assembly 500, wherein embedded sleeve 200 is connected with containment 100;Embedded sleeve 200 and first sealing ring plate 300 and second sealing ring plate 400 are prefabricated components, and are embedded and installed in containment 100, wherein first sealing ring plate 300 is arranged in the inner cavity of containment 100, and is embedded and connected with the inner lateral wall of containment 100;Second sealing ring plate 400 is arranged on the outer wall of containment 100, and is embedded and connected with the outer lateral wall of containment 100;

[0039] Head assembly 500 is sealingly installed at the end of embedded sleeve 200 located outside containment 100, to ensure the sealing connection between the through piece and containment 100.

[0040] Referring to Figure 3 And Figure 4 In the embodiment of the utility model penetration connection structure, the penetration connection structure further includes first sealing layer 700;First sealing layer 700 is coated between first sealing ring plate 300 and the inner lateral wall of containment 100, specifically, first sealing layer 700 is formed by coating sealant, since first sealing ring plate 300 is embedded and installed in the lateral wall of containment 100, therefore, the annular lateral wall of first sealing ring plate 300 is coated with sealant in the gap embedded in containment 100, to form a sealant layer between first sealing ring plate 300 and the inner lateral wall of containment 100, i.e. first sealing layer 700;To achieve the effect of preventing leakage, the type of sealant is not limited, which can be any suitable type of product that meets the actual process requirements and can be obtained through general commercial means.And in order to ensure the coating sealing effect of first sealing layer 700 on the gap, the outer plate surface of first sealing ring plate 300 is flush with the inner lateral wall of containment 100, so that the contactable area between first sealing ring plate 300 and the inner lateral wall of containment 100 is increased compared with the contactable area between containment 100 and embedded sleeve 200, which makes it easier to brush sealant and achieve good sealing effect.

[0041] Further, in the embodiment of the through connection structure, the through connection structure further comprises a second sealing layer 800; the second sealing layer 800 is similar to the first sealing layer 700 in structure and function, and is formed by sealing glue; the second sealing layer 800 is coated between the second sealing ring plate 400 and the outer side wall of the safety shell 100, the gap between the second sealing ring plate 400 and the outer side wall of the safety shell 100 is filled and sealed, redundant protection is formed on the basis of the first sealing layer 700, and finally the sealing effect between the through part and the safety shell is ensured.

[0042] In the through part and the through structure for the safety shell of the nuclear power plant, the through part is sleeved and installed on the first sealing ring plate and the second sealing ring plate of the embedded sleeve pipe, is attached and blocked on the inner and outer side walls of the safety shell, thereby prolonging the gas leakage path of the gap between the embedded sleeve pipe and the safety shell. The convex structure of the first sealing ring plate can effectively fix and connect the embedded sleeve pipe in the safety shell, realize the sealing of the safety shell and the through part, and increase the reliability of the through part connection, so as to solve the technical problems of poor sealing effect and reduced reliability of the safety shell and the through part without a steel lining structure. Therefore, the utility model effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance.

[0043] The above embodiment only exemplarily illustrates the principle and effect of the utility model, and is not used for limiting the utility model. Any person skilled in the art can modify or change the above embodiment without departing from the spirit and scope of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.

Claims

1. A penetration for a nuclear power plant containment, characterized in that, The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell.

2. A through going member according to claim 1, characterised in that, The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell.

3. A through going member according to claim 2, characterised in that, The application relates to a through-connection structure of a safety shell.

4. The through going member of claim 1, wherein, The application relates to a through-connection structure of a safety shell.

5. The through going member of claim 1, wherein, The application relates to a through-connection structure of a safety shell.

6. A through going member according to claim 5, characterised in that, The application relates to a through-connection structure of a safety shell.

7. The through going member of claim 5, wherein, The application relates to a through-connection structure of a safety shell.

8. A penetration connection structure for a containment of a nuclear power plant, characterized by, The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell.

9. The penetration connection structure according to claim 8, characterized by The application relates to a through-connection structure of a safety shell.

10. The penetration connection structure according to claim 9, wherein The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application relates to a through-connection structure of a safety shell. The application

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