Composite plugging device for cable hole

Abstract

The invention belongs to a plugging device, and particularly relates to a cable hole composite plugging device. The cable hole composite plugging device comprises an electrical sealing element and a plugging material, and the electrical sealing element and the plugging material are tightly attached to form the cable hole composite plugging device. Compared with the prior art, the two composite plugging devices provided by the invention have the following beneficial effects that the electrical sealing pieces and different fireproof plugging materials are combined and applied to replace an electrical penetration piece which is high in manufacturing cost and large in occupied area in a large cable penetration area; the cable has high loading capacity, air tightness and water tightness, and also has the functions of 2-hour fire endurance, radiation resistance, biological shielding and the like.

Description

Technical Field

[0001] The present invention belongs to a plugging device, and particularly relates to a composite cable hole plugging device. Background Art

[0002] In recent years, with the continuous increase of the country's support for the nuclear energy industry, the development prospect of the Chinese nuclear energy industry is very broad. As the fourth generation of nuclear reactors, high-temperature gas-cooled reactors have two major characteristics of inherent "inherent safety" and "high-temperature medium", and have broad application prospects in nuclear power generation, heavy oil thermal recovery, coal gasification, natural gas steam reforming and hydrogen production by cracking. To ensure the safe operation of nuclear power plants, after the cables are installed, the cable holes need to be plugged to meet various safety requirements such as fire prevention, flood prevention, radiation protection and biological shielding in the plant.

[0003] Currently, in nuclear power plants, the plugging methods for cable holes generally include four types: plugging material - low-density silicone foam plugging, plugging material - high-density silicone elastomer plugging, electrical seal MCT plugging and electrical penetration plugging. Each of these four plugging methods has its own advantages and disadvantages. Specifically:

[0004] (1) Fireproof plugging material - low-density silicone foam plugging. Its main advantages are having a 2-hour fire resistance limit, radiation resistance, convenient construction, low cost and a 60-year lifespan. However, it does not have a biological shielding function, and its airtight and watertight performance is very low, and its pressure-bearing capacity is also low.

[0005] (2) Fireproof plugging material - high-density silicone elastomer plugging. Its main advantages are having a 2-hour fire resistance limit, radiation resistance, having a biological shielding function and a 60-year lifespan, relatively high airtight and watertight performance, and relatively high pressure-bearing capacity, but lower than MCT. Due to its large density, the construction period is long and the cost is high.

[0006] (3) Electrical seal MCT plugging. Its advantages are having a higher pressure-bearing capacity, airtight and watertight performance than high-density silicone elastomers, and also having radiation resistance. However, its disadvantage is that single-sided MCT does not have a 2-hour fire resistance limit, and the current process technology only allows it to have a maximum lifespan of 20 years. Therefore, it needs to be replaced multiple times during the long lifespan of large projects (such as 60 years in nuclear power plants), and the maintenance cost is high. In addition, the modular design also means that it requires a larger hole area, and its high-temperature resistance ability is weak and cannot exceed 80°C.

[0007] (4) Electrical penetration plugging. Electrical penetrations have strong pressure-bearing capacity, airtight and watertight performance, and also have radiation resistance, biological shielding, fire resistance performance and a 60-year lifespan. It is a common cable penetration method for the containment of pressurized water reactor nuclear power plants. However, it is expensive and occupies a large space, and is not suitable for a large number of cable penetrations.

[0008] In summary, the plugging forms of the existing technologies are relatively single and can only meet the basic requirements for plugging cable holes. However, according to the characteristics of the high-temperature gas-cooled reactor, for the "low-pressure-resistant and ventilated" containment and the main control room, due to the new environmental conditions and functional requirements, the single cable hole plugging method can no longer meet the requirements. We need to seek a new plugging method to replace the expensive and large-footprint electrical penetrations in the area where a large number of cables penetrate. It should have both high pressure-bearing capacity, airtight and watertight performance, and also functions such as a 2-hour fire resistance limit, radiation resistance, and biological shielding. Summary of the Invention

[0009] The object of the present invention is to provide a composite cable hole plugging device to address the deficiencies of the existing technologies.

[0010] The specific technical solution adopted by the present invention is as follows: A composite cable hole plugging device, which includes an electrical seal and a plugging material. The electrical seal and the plugging material are closely arranged to form the composite cable hole plugging device.

[0011] For the composite cable hole plugging device as described above, the thickness of the electrical seal is 60 mm, and the remaining wall thickness is entirely filled with the plugging material.

[0012] For the composite cable hole plugging device as described above, the cross-section of the electrical seal is grid-shaped, and the channels formed by the grid shape are for the cables to pass through.

[0013] For the composite cable hole plugging device as described above, a pressing module is arranged on the side of the electrical seal, and the pressing module is used to press the passing cables.

[0014] For the composite cable hole plugging device as described above, an electrical seal rubber module is arranged on the electrical seal, and the electrical seal rubber module is used to block some of the grids, and the unblocked grids form mutually isolated cable channels.

[0015] For the composite cable hole plugging device as described above, the size of the electrical seal rubber module is greater than or equal to 30 mm.

[0016] For the composite cable hole plugging device as described above, the plugging material is a low-density silicone foam plugging material or a high-density silicone elastomer.

[0017] For the composite cable hole plugging device as described above, when the plugging material is a high-density silicone elastomer, a silicone cloth is added between the electrical seal and the high-density silicone elastomer, and the smooth surface of the silicone cloth faces the electrical seal.

[0018] A cable hole composite plugging device as described above, wherein the cable hole composite plugging device further includes an angle steel support, which is arranged at the hole of the wall for supporting the cable.

[0019] A cable hole composite plugging device as described above, wherein the electrical seal is arranged on the low-temperature side of the wall, and the high-density silicone elastomer is arranged on the high-temperature side of the wall.

[0020] The present invention has the following beneficial effects compared with the prior art: The two composite plugging devices provided by the present invention, by combining the electrical seal and different fireproof plugging materials, are used to replace the expensive and large-footprint electrical penetrators in areas with a large number of cable penetrations. They can not only have high pressure-bearing capacity, airtight and watertight performance, but also have functions such as a 2-hour fire resistance limit, radiation resistance, and biological shielding.

[0021] Compared with electrical penetrators, it is cheaper in cost and smaller in floor area. The cables do not need to be disconnected, reducing the number of wire connection points and the failure rate, and is more suitable for areas with a large number of cable penetrations.

[0022] Compared with the single plugging materials of low-density silicone foam and high-density silicone elastomer, it has higher pressure-bearing capacity, airtight and watertight capabilities, and is more suitable for environments requiring pressure-bearing and radioactive gas containment under accident conditions.

[0023] Compared with a single electrical seal, it solves the problem that the 2-hour fire resistance limit cannot be guaranteed by single-sided installation, and double-sided installation will accelerate the aging of cables in the enclosed space. In addition, it prevents the damage of the electrical seal by the high-temperature environment under accident conditions, and also solves the problem that it cannot undertake the function of biological shielding. Description of the Drawings

[0024] Figure 1 It is a diagram of the composite plugging device of electrical seal MCT + low-density silicone foam.

[0025] Figure 2 It is a schematic diagram of the isolation layout of cables in different safety channels in the composite plugging device.

[0026] Figure 3 It is the composite plugging device of electrical seal MCT + high-density silicone elastomer.

[0027] In the figure: 1 switchgear; 2 switchgear channel steel support; 3 floor slab; 4 low-density silicone foam plugging material; 5 electrical seal; 6 frame; 7 pressing module; 8 wall; 9 silicone cloth; 10 angle steel support; 11 high-density silicone elastomer; 12 cable tray; 13 high-temperature side; 14 low-temperature side. Detailed Embodiments

[0028] The present invention will be further described and explained below in conjunction with the accompanying drawings and specific embodiments.

[0029] The present invention provides a new way of sealing cable holes. By combining electrical seals and fireproof sealing materials, two composite sealing devices are formed, which are suitable for different engineering environments:

[0030] Electrical seal MCT + low-density silicone foam composite sealing device

[0031] The typical structure of this device is as shown in the appendix Figure 1 shown. Combining the advantages of two materials, electrical seal MCT and low-density silicone foam, the electrical seal MCT undertakes the airtight function, and the low-density silicone foam undertakes the requirement of 2-hour fire resistance. It is mainly applicable to places with high airtight requirements and requiring a fire resistance limit of 2 hours or more, such as the main control room in a nuclear power plant;

[0032] As the command center of a nuclear power plant, the safety of the main control room in a nuclear power plant is particularly important. In the event of an accident, it is required that the main control room maintain a slightly positive pressure to maintain habitability. Therefore, it is necessary to maintain the airtightness of the cable hole seals on the boundary. The switchgear in the main control room adopts the method of incoming and outgoing lines from below. Holes are directly drilled on the floor below the switchgear to enter the fire compartment below. Therefore, as the boundary of the fire compartment, at least 2-hour fireproof sealing is also required. In addition, there are some safety-class switchgears in the main control room, and there are situations where multiple redundant safety channels A, B, C, D, N enter the same safety switchgear. According to relevant standard specifications, isolation measures need to be taken. The electrical seal rubber module in the composite sub-sealing device can be used for isolation of different safety channels. For details, see Figure 2 .

[0033] Electrical seal MCT + high-density silicone elastomer composite sealing device

[0034] This device combines the advantages of two materials, electrical seal MCT and high-density silicone elastomer. The electrical seal MCT undertakes high pressure-bearing capacity, airtight and watertight performance, and the high-density silicone elastomer undertakes radiation resistance, 2-hour fire resistance limit, biological shielding requirements and the protection function of MCT in high-temperature environments. It is mainly applicable to places with high pressure-bearing capacity, airtight and watertight performance, and must have a fire resistance limit of 2 hours or more, radiation resistance, and biological shielding. Compared with electrical penetrations, it is more suitable for a large number of cable penetrations, such as the containment of a high-temperature gas-cooled reactor nuclear power plant;

[0035] Its typical structure is as Figure 2As shown in the figure, before cable laying, an electrical seal frame is installed on the low-temperature side in the reserved cable holes or embedded sleeves. When laying the cables, the rubber modules of the electrical seals are used to clamp each cable passing through the hole and install them in the frame respectively to ensure its airtightness, watertightness and pressure-bearing capacity. The thickness of the electrical seal is generally only 60 mm. After the cable laying is completed, the remaining wall thickness is filled with high-density silicone elastomer to ensure its performance requirements such as biological shielding, fire resistance and radiation resistance. Generally, a steel grid is used to support the cables passing through the hole, but in this device, support angle steels are added at the hole to support the cables, which is convenient for cable laying construction and the construction of the later pouring and plugging materials. In addition, although the high-density silicone elastomer has a service life of 60 years, the current process technology of MCT makes its rubber module only have a maximum service life of 20 years. Considering the later replacement, a silicon cloth is added between the electrical seal and the high-density silicone elastomer plugging material, and the smooth surface of the silicon cloth faces the electrical seal to prevent the electrical seal from adhering to the high-density silicone elastomer, resulting in the situation where the rubber module cannot be replaced.

[0036] Figure 2 In it, S1≥30 mm, S2≥30 mm, S3≥30 mm.

Claims

1. A composite cable hole plugging device, characterized in that: It includes an electrical seal (5) and a plugging material. The electrical seal (5) is closely arranged with the plugging material to form a composite plugging device for cable holes.

2. The composite cable hole plugging device according to claim 1, characterized in that: The thickness of the electrical seal (5) is 60 mm, and the remaining wall thickness is fully filled with the plugging material.

3. The composite cable hole plugging device according to claim 2, characterized in that: The cross-section of the electrical seal (5) is grid-shaped, and the channels formed by the grid shape are used for the cables to pass through.

4. The composite cable hole plugging device according to claim 3, characterized in that: The rubber module and the pressing module (7) of the electrical seal (5) are adopted to ensure high tightness when the cable passes through the hole.

5. The composite cable hole plugging device according to claim 4, characterized in that: An electrical seal rubber module is arranged on the electrical seal (5). The electrical seal rubber module is used to fix a single cable in each frame. The grids without cables passing through can also be filled with complete rubber modules to form mutually isolated cable channels.

6. The composite cable hole plugging device according to claim 5, characterized in that: The plugging material is a low-density silicone foam plugging material (4) or a high-density silicone elastomer (11).

7. The composite cable hole plugging device according to claim 6, characterized in that: When the plugging material is a high-density silicone elastomer (11), a silicone cloth is added between the electrical seal (5) and the high-density silicone elastomer (11). The smooth surface of the silicone cloth faces the electrical seal, which is convenient for replacing the rubber module of the electrical seal at the end of its service life.

8. The composite cable hole plugging device according to claim 7, characterized in that: The composite plugging device for cable holes further includes an angle steel support (10). The angle steel support (10) is arranged at the opening of the wall body and is used to support the cable.

9. The composite cable hole plugging device according to claim 8, characterized in that: The electrical seal (5) is arranged on the low-temperature side (14) of the wall body, and the high-density silicone elastomer (11) is arranged on the high-temperature side (13) of the wall body.

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