Rail transit composite water-blocking cable and water-blocking device thereof

Abstract

The invention relates to the technical field of water-blocking cables, and discloses a rail transit composite water-blocking cable and a water-blocking device thereof, the rail transit composite water-blocking cable comprises a cable body and water-blocking assemblies, and the water-blocking device comprises a plurality of groups of water-blocking assemblies. The water blocking assembly comprises a first water blocking unit, a second water blocking unit, a third water blocking unit, a fourth water blocking unit, a fifth water blocking unit and a sixth water blocking unit which are evenly arranged in the circumferential direction of the cable body, and the first water blocking unit comprises a first cement supporting layer, a second cement supporting layer, an SAP water absorption layer, a hydrogel water absorption layer and an electric heating wire; the SAP water absorption layer, the first cement supporting layer and the second cement supporting layer are arranged in the cable body, the self-healing capability of the cable body in use can be greatly improved while infiltrated water can be utilized to realize benefit conversion and effective utilization of the water, the water in the SAP water absorption layer, the first cement supporting layer and the second cement supporting layer can be evaporated by utilizing the electric heating wire, waterproof sealing is completed, and the service life of the cable body is prolonged. And meanwhile, the supporting strength of the cable body can be enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of water-blocking cables, and in particular to a rail transit composite water-blocking cable and a water-blocking device thereof. Background Art

[0002] Urban rail transit is currently the main measure for improving the traffic environment in major international cities. Due to the particularity of rail transit, the safety and reliability requirements of the power system are extremely high. Due to the influence of environmental and meteorological factors, cables for urban light rail subways may be laid in a humid environment for a long time. Water molecules may penetrate into the cables and invade the interior of the cables. They will be absorbed by the insulation, causing a decrease in electrical performance and oxidation and corrosion of the conductors, which will not only affect the electrical performance of the cables, but also cause abnormal disconnection accidents in serious cases.

[0003] A copper wire shielded dynamic control composite water-blocking cable for urban rail transit with application number CN201510893256.4, the control line core layer includes a wrapped high flame retardant water-blocking tape, an extruded second inner sheath layer, an extruded outer sheath layer, and a metal water-blocking protective layer from the inside to the outside, with high insulation performance, flame retardant grade A, low smoke and halogen-free, good comprehensive water-blocking effect, anti-rat and anti-ant, anti-ultraviolet, anti-electric field interference, and good bending performance; a water-blocking cable with application number CN202022588453.4, a hydrogel is arranged in the water-blocking tape, and the hydrogel absorbs moisture entering the cable and expands to form a water-blocking dam, thereby locking the moisture and avoiding the diffusion of moisture, improving the waterproof and electrical properties of the cable, and avoiding insulation damage.

[0004] However, although the double-layer sheath and metal water-blocking sheath on the outside of the cable can increase radial waterproofness, during the operation of the cable, especially during the power supply operation, if a local cable breakdown occurs, moisture will penetrate into the cable through the breakdown point, causing leakage hazards. The hydrogel used in the above documents achieves waterproofing by absorbing water. However, this application measure is only a remedial measure, and because the hydrogel has good water absorption, it will aggravate the penetration of moisture, posing a safety hazard and failing to fundamentally solve the problem of cable water seepage.

[0005] Therefore, the present invention solves the above-mentioned problem through a rail transit composite water-blocking cable and a water-blocking device thereof. Summary of the invention

[0006] The object of the present invention is to provide a rail transit composite water-blocking cable and a water-blocking device thereof to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: a rail transit composite water-blocking cable, comprising a cable body and a water-blocking assembly, wherein the water-blocking assembly comprises a first water-blocking unit, a second water-blocking unit, a third water-blocking unit, a fourth water-blocking unit, a fifth water-blocking unit and a sixth water-blocking unit uniformly arranged along the circumferential direction of the cable body; The cable body comprises a protective layer, an inner extrusion package of the protective layer is provided with a shielding layer, an outer extrusion package of the protective layer is provided with a water-blocking layer, the water-blocking component is embedded in the protective layer, and a water-blocking groove matching the water-blocking component is provided in the protective layer; The first water-blocking unit includes a water-blocking support seat fixed inside the water-blocking groove near the shielding layer side, and also includes a first cement supporting layer and a second cement supporting layer fixed inside the water-blocking groove near the water-blocking layer side, the first cement supporting layer and the second cement supporting layer are arranged at intervals, the first cement supporting layer and the second cement supporting layer are wrapped around the outside of the SAP water-absorbing layer, and the SAP water-absorbing layer is integrally provided with a first water-blocking section arranged between the first cement supporting layer and the second cement supporting layer, and the SAP water-absorbing layer is integrally provided with a second water-blocking section arranged between the water-blocking support seat and the first cement supporting layer.

[0008] Preferably, the first water-blocking unit, the second water-blocking unit, the third water-blocking unit, the fourth water-blocking unit, the fifth water-blocking unit and the sixth water-blocking unit have the same structure, and a hydrogel water-absorbing layer is filled between each group of the SAP water-absorbing layer and the water-blocking supporting seat.

[0009] Preferably, a pressurized air bag is arranged at the center of the hydrogel water-absorbing layer, two adjacent groups of the pressurized air bags are connected by a pressure relief air pipe, and a pressure relief valve is fixedly mounted on each group of the pressure relief air pipe.

[0010] Preferably, the hydrogel water-absorbing layer consists of a non-woven bag and hydrogel, and the non-woven bag is filled with hydrogel, and the size of the hydrogel water-absorbing layer matches the size of the water-blocking groove, the pressurized air bag is elliptical, and the length of the pressurized air bag is the same as the length of the water-blocking groove.

[0011] Preferably, the first water-isolating section and the second water-isolating section are both strip-shaped, the SAP water-absorbing layer is embedded with a winding electric heating wire, the electric heating wire runs through the second water-isolating section, the SAP water-absorbing layer and the first water-isolating section, and the SAP water-absorbing layer is embedded with conductive terminals corresponding to the two ends of the electric heating wire.

[0012] Preferably, the cable body also includes a core conductor at the center, the outer wall of the core conductor is extruded with an insulating sheath, and the insulating sheath is arranged on the inner side of the shielding layer, the outer wall of the water-blocking layer is extruded with a flame retardant layer, and the outer wall of the flame retardant layer is extruded with an outer sheath.

[0013] Preferably, the top of the water-blocking groove is in contact with the water-blocking layer, the bottom of the water-blocking groove is in contact with the shielding layer, and the water-blocking support seat is an arched reinforcement seat in contact with the inner side wall of the water-blocking groove.

[0014] The present invention discloses a water-blocking device, which comprises a plurality of groups of water-blocking components, and the water-blocking components are arranged linearly along the length direction of a cable body. The distribution positions of the water-blocking components are planned according to the actual application environment, so as to achieve the purpose of targeted waterproof and pressure-resistant protection based on the working environment, and can well realize the self-protection of the cable.

[0015] Technical effects and advantages of the present invention: 1. The cable body of the present invention has multiple sets of water-blocking components embedded in it, which can realize overall waterproof protection for the cable body. Of course, in actual use, the distribution position of the water-blocking components is planned according to the actual application environment to achieve the purpose of targeted waterproof and pressure-resistant protection based on the working environment, which can well realize the self-protection of the cable.

[0016] 2. When the amount of water infiltration is small, the water-blocking device in the present invention first absorbs the water through the outermost first cement supporting layer or the second cement supporting layer to complete the preliminary water absorption operation, and then fills the cracks. The SAP water-absorbing layer can absorb the water and use its own adhesion after absorbing water to fill the water seepage and complete self-seepage remediation. In this way, the infiltrated water can be used to achieve benefit conversion and achieve effective utilization of water. While avoiding further water infiltration, the self-healing ability of the cable body during use is greatly improved.

[0017] 3. When a large amount of water penetrates into the water-blocking device of the present invention, the excess water in the SAP water-absorbing layer will be absorbed by the hydrogel water-absorbing layer. In this way, the hydrogel water-absorbing layer will expand after the water absorption is completed. The squeezing force on the SAP water-absorbing layer is achieved through its own expansion, thereby increasing the density of the SAP water-absorbing layer and slowing down the water seepage rate. Moreover, the electric heating wire is connected to the circuit and starts working, which can evaporate the water inside the SAP water-absorbing layer, the first cement supporting layer and the second cement supporting layer, making it convenient to reuse the SAP water-absorbing layer to complete the secondary water absorption operation. The first cement supporting layer and the second cement supporting layer will solidify due to the evaporation of water, which not only completes the waterproof seal, but also can enhance the supporting strength of the cable body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the cable body structure of the present invention; Figure 2 It is a schematic diagram of the longitudinal cross-sectional structure of the cable body of the present invention; Figure 3 It is a schematic diagram of a partial cross-sectional structure of a cable body of the present invention; Figure 4 This is a schematic diagram of the structure of the cable body and the water blocking device of the present invention assembled from a first perspective; Figure 5 It is a schematic diagram of the structure of the water blocking device of the present invention; Figure 6 This is a schematic diagram of the structure of the cable body and the water blocking device of the present invention assembled from a second viewing angle; Figure 7 It is a schematic diagram of the enlarged structure of part A of the present invention; Figure 8 This is a schematic diagram of the structure of the water blocking component of the present invention; Fig. 9 This is a schematic structural diagram of the first water-blocking unit of the present invention; Fig.10 This is a schematic diagram of the structure of the water blocking component of the present invention in use state.

[0019] In the figure: 10, cable body; 11, core conductor; 12, insulating sheath; 13, shielding layer; 14, protective layer; 15, water-blocking layer; 16, flame-retardant layer; 17, outer sheath; 18, water-blocking groove; 20, first water-blocking unit; 21, water-blocking support seat; 22, first cement supporting layer; 23, second cement supporting layer; 24, SAP water-absorbing layer; 25, first water-isolating section; 26, second water-isolating section; 27, electric heating wire; 28, hydrogel water-absorbing layer; 29, pressurized air bag; 210, pressure relief air pipe; 30, second water-blocking unit; 40, third water-blocking unit; 50, fourth water-blocking unit; 60, fifth water-blocking unit; 70, sixth water-blocking unit. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] This embodiment provides Figures 1 to 10 A rail transit composite water-blocking cable shown in the figure includes a cable body 10 and a water-blocking component. When the cable body 10 is in use, not only is the cable body 10 used to protect itself, but the water-blocking component can also be used to strengthen the waterproof protection of the internal wire core by the cable body 10. The water-blocking component includes a first water-blocking unit 20, a second water-blocking unit 30, a third water-blocking unit 40, a fourth water-blocking unit 50, a fifth water-blocking unit 60 and a sixth water-blocking unit 70 uniformly arranged along the circumferential direction of the cable body 10. A water-blocking structure is arranged inside the cable body 10 along the circumferential direction, which can strengthen the water-blocking protection of the cable body 10 and prevent moisture from penetrating and causing a short circuit in the wire core.

[0022] The cable body 10 includes a protective layer 14, the inner side of the protective layer 14 is extruded with a shielding layer 13, the outer side of the protective layer 14 is extruded with a water-blocking layer 15, the water-blocking component is embedded in the protective layer 14, and the protective layer 14 is provided with a water-blocking groove 18 matching the water-blocking component. The cable body 10 also includes a core conductor 11 at the center, the outer side wall of the core conductor 11 is extruded with an insulating sheath 12, and the insulating sheath 12 is arranged on the inner side of the shielding layer 13, the outer side wall of the water-blocking layer 15 is extruded with a flame-retardant layer 16, and the outer side wall of the flame-retardant layer 16 is extruded with an outer sheath 17.

[0023] When in use, the outer sheath 17 ensures the wear resistance of the cable, while the flame retardant layer 16 improves the corrosion and fire resistance of the cable, the water-blocking layer 15 enhances the waterproof protection, the shielding layer 13 ensures the electromagnetic shielding of the core conductor 11, and the insulating sheath 12 can ensure the insulation protection of the core conductor 11, and the protective layer 14 can strengthen the water-blocking effect of the water-blocking layer 15, so as to improve the protection of the shielding layer 13 and prevent moisture from penetrating and affecting the normal operation of the core conductor 11.

[0024] See also Figure 2-Figure 4 The first water-blocking unit 20 includes a water-blocking support seat 21 fixed inside the water-blocking groove 18 near the shielding layer 13. The top of the water-blocking groove 18 is in contact with the water-blocking layer 15, and the bottom of the water-blocking groove 18 is in contact with the shielding layer 13. The water-blocking support seat 21 is an arched reinforcement seat in contact with the inner wall of the water-blocking groove 18, thereby improving the supporting protection and strengthening the supporting strength of the cable body 10.

[0025] See also Figure 4-Figure 9 The first water-blocking unit 20 further includes a first cement supporting layer 22 and a second cement supporting layer 23 fixed inside the water-blocking groove 18 near one side of the water-blocking layer 15. The first cement supporting layer 22 and the second cement supporting layer 23 are arranged at intervals. The first cement supporting layer 22 and the second cement supporting layer 23 are wrapped around the outside of the SAP water-absorbing layer 24, and a first water-blocking section 25 arranged between the first cement supporting layer 22 and the second cement supporting layer 23 is integrally formed on the SAP water-absorbing layer 24, and a second water-blocking section 26 arranged between the water-blocking support seat 21 and the first cement supporting layer 22 is integrally formed on the SAP water-absorbing layer 24.

[0026] It should be noted that SAP (Super Absorbent Polymer) is a synthetic polymer material with extremely high water absorption capacity. This material can absorb and retain water equivalent to hundreds or even thousands of times its own weight. Due to its unique physical and chemical properties, SAP material has a wide range of applications in many fields.

[0027] It should be noted that the first cement support layer 22 is angled and arranged at the top corner of the water blocking groove 18, while the cross-section of the second cement support layer 23 is arc-shaped and has the same thickness as the first cement support layer 22. The second cement support layer 23 is provided in two groups and arranged between the two groups of first cement support layers 22. It is also attached to the inner wall of the water blocking layer 15, has a high degree of fit, and a large specific surface area, which is convenient for absorbing the infiltrated water. The first water-blocking section 25 is filled between the first cement support layer 22 and the second cement support layer 23, which ensures the compactness of the structure while facilitating the first water-blocking section 25 to penetrate into the water blocking layer 15, the first cement support layer 22, and the second The connection between the cement supporting layer 23 structures. Similarly, the second water-blocking section 26 can penetrate into the connection between the first cement supporting layer 22, the protective layer 14, and the water-blocking support seat 21, and the SAP water-absorbing layer 24 has a strong water absorption capacity. After absorbing water, SAP will self-solidify into a colloidal substance and have good adhesion. It uses its own adhesion after absorbing water to fill the seepage points, complete self-seepage remediation, avoid further water seepage, and achieve a preliminary water-blocking effect. At the same time, it enhances the limiting properties of the first cement supporting layer 22 and the second cement supporting layer 23 inside the water-blocking groove 18, which can effectively fill the gaps between the structures.

[0028] See also Figure 6 and Figure 7 The first water-blocking unit 20, the second water-blocking unit 30, the third water-blocking unit 40, the fourth water-blocking unit 50, the fifth water-blocking unit 60 and the sixth water-blocking unit 70 have the same structure, and a hydrogel water-absorbing layer 28 is filled between each group of SAP water-absorbing layers 24 and the water-blocking support seat 21. The water-blocking support seat 21 can act as a reinforcing rib to achieve anti-torsion protection for the cable body 10, and can also support and limit the hydrogel water-absorbing layer 28, so that the hydrogel water-absorbing layer 28 generates an extrusion force on the SAP water-absorbing layer 24 after absorbing water and swelling, thereby enhancing the density of the SAP water-absorbing layer 24 distributed in the water-blocking groove 18, increasing the filling amount of the water seepage point based on its own adhesion, and improving the anti-water seepage performance.

[0029] See also Figure 7-Figure 9 A pressurized air bag 29 is arranged at the center of the hydrogel water-absorbing layer 28, and two adjacent groups of pressurized air bags 29 are connected by a pressure relief air pipe 210, and a pressure relief valve is fixedly installed on each group of pressure relief air pipes 210. After the hydrogel water-absorbing layer 28 completes water absorption, it will expand, and realize the squeezing force on the SAP water-absorbing layer 24 through its own expansion. Moreover, after the hydrogel water-absorbing layer 28 expands, the pressurized air bag 29 will be squeezed synchronously, so that the water absorption amount of the hydrogel water-absorbing layer 28 can be reflected by the internal pressure value of the pressurized air bag 29 after squeezing and shrinking, so as to perform real-time detection of the water seepage of the cable body 10, facilitate inspection and maintenance, and enhance real-time protection.

[0030] It should be noted that the hydrogel water-absorbing layer 28 is composed of a non-woven bag and hydrogel, and the non-woven bag is filled with hydrogel, and the size of the hydrogel water-absorbing layer 28 matches the size of the water-blocking groove 18, the pressurized air bag 29 is elliptical, and the length of the pressurized air bag 29 is the same as the length of the water-blocking groove 18, so that when the hydrogel inside the hydrogel water-absorbing layer 28 absorbs water, it will expand, thereby completing the extrusion of the SAP water-absorbing layer 24, causing it to fit closely on the inner wall of the water-blocking groove 18, enhancing the compaction degree, and achieving a water-blocking effect.

[0031] See 7 and Fig. 9 The first water-isolating section 25 and the second water-isolating section 26 are both strip-shaped, and a winding electric heating wire 27 is embedded in the SAP water-absorbing layer 24. The electric heating wire 27 runs through the second water-isolating section 26, the SAP water-absorbing layer 24 and the first water-isolating section 25, and the SAP water-absorbing layer 24 has built-in conductive terminals corresponding to the two ends of the electric heating wire 27.

[0032] When the hydrogel water-absorbing layer 28 absorbs water, the pressurized air bag 29 is squeezed, the internal gas pressure increases, and the pressure relief valve can detect the internal pressure value in real time, which is convenient for controlling the two sets of conductive terminals to be energized, prompting the electric heating wire 27 to be connected to the circuit and start working, and can heat the SAP water-absorbing layer 24 to achieve drying treatment, so that the moisture inside the SAP water-absorbing layer 24 can be evaporated, which is convenient for its reuse, and the evaporated moisture can be absorbed by the hydrogel water-absorbing layer 28, further increasing the expansion of the hydrogel water-absorbing layer 28, and increasing the squeezing force on the SAP water-absorbing layer 24. At the same time, the expanded hydrogel water-absorbing layer 28 can provide the cable body 10 with a better pressure-resistant buffer effect.

[0033] The present embodiment also discloses a water-blocking device, which includes a plurality of groups of water-blocking components, and the water-blocking components are linearly arranged along the length direction of the cable body 10, so that the cable body 10 can be provided with overall waterproof protection through the water-blocking components. Of course, in actual use, the distribution position of the water-blocking components is planned according to the actual application environment, so as to achieve the purpose of targeted waterproof and pressure-resistant protection based on the working environment.

[0034] Specifically, when the cable body 10 is partially damaged or cracked due to extrusion during use, external moisture will flow into the water blocking groove 18 along the crack. At this time, the moisture is first absorbed by the outermost first cement supporting layer 22 or the second cement supporting layer 23 to complete the preliminary water absorption operation. At this time, the first cement supporting layer 22 or the second cement supporting layer 23 is in a mud state. As the water absorption amount of the first cement supporting layer 22 or the second cement supporting layer 23 increases, the SAP water absorbing layer 24 can absorb the moisture. After absorbing the moisture, SAP will self-solidify into a colloidal substance with good adhesion. It uses its own adhesion after absorbing water to fill the water seepage and complete self-seepage remediation. At the same time, the first cement supporting layer 22 or the second cement supporting layer 23 is filled to the crack to repair the crack. In this way, the infiltrated moisture can be used to achieve benefit conversion, achieve effective utilization of moisture, avoid further infiltration of moisture, and greatly improve the self-healing ability of the cable body 10 during use.

[0035] It should be noted that when the cable body 10 is broken during actual use and the cracks are large, the water penetration rate increases. At this time, the adhesion of the SAP water-absorbing layer 24 alone is not enough to make up for the cracks, resulting in a large amount of water seepage. At this time, the excess water in the SAP water-absorbing layer 24 will be absorbed by the hydrogel water-absorbing layer 28, so that after the hydrogel water-absorbing layer 28 completes the water absorption, it will expand, and achieve the squeezing force on the SAP water-absorbing layer 24 through its own expansion, increase the density of the SAP water-absorbing layer 24, and slow down the water seepage rate. When the pressure relief valve detects that the gas pressure value inside the pressurized air bag 29 reaches the first threshold, it indicates that the water absorption of the hydrogel water-absorbing layer 28 reaches the first warning threshold, indicating that the amount of water infiltrated into the water-blocking groove 18 is large. At this time, the two sets of conductive terminals are controlled to be energized, prompting the electric heating wire 27 to connect to the circuit and start working, so that the SAP water-absorbing layer 24, the first cement supporting layer 22, and the second cement supporting layer 23 can be heated to achieve drying treatment. In this way, the water inside the SAP water-absorbing layer 24, the first cement supporting layer 22, and the second cement supporting layer 23 can be evaporated, which is convenient for the SAP water-absorbing layer 24 to be reused to complete the secondary water absorption operation, and the first cement supporting layer 22 and the second cement supporting layer 23 will solidify due to the evaporation of water, so that the first cement supporting layer 22 and the second cement supporting layer 23 filled in the cracks complete the repair work, not only completing the waterproof seal, but also enhancing the supporting strength of the cable body 10, and the evaporated water can be absorbed by the hydrogel water-absorbing layer 28, further increasing the expansion of the hydrogel water-absorbing layer 28, and increasing the squeezing force on the SAP water-absorbing layer 24, the first cement supporting layer 22, and the second cement supporting layer 23, and cooperate with the heating and drying operation of the electric heating wire 27 to complete the crack repair and achieve self-repair. Moreover, when the cable body 10 is squeezed by the outside, the expanded hydrogel water-absorbing layer 28 can enhance the compressive buffering property of the cable body 10 by using its own elasticity.

[0036] It should be noted that when the hydrogel water-absorbing layer 28 absorbs a large amount of water, the squeezing force on the pressurized air bag 29 will increase. When the gas inside it increases to the second warning threshold, it indicates that the amount of water seepage inside the water-blocking groove 18 is too large, which seriously affects the safety of the cable body 10. At this time, the pressure relief valve is opened, prompting the gas in the pressurized air bag 29 to be introduced into the adjacent water-blocking unit through the pressure relief air pipe 210 to achieve pressure relief, making it convenient for the hydrogel water-absorbing layer 28 to absorb water again, thereby completing the extreme water-blocking protection of the cable body 10. At the same time, the cable body 10 sends a maintenance signal to the remote control end through the core conductor 11, alerting the staff to perform rapid maintenance.

[0037] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite water-blocking cable for rail transit, characterized in that: The invention comprises a cable body (10) and a water-blocking assembly, wherein the water-blocking assembly comprises a first water-blocking unit (20), a second water-blocking unit (30), a third water-blocking unit (40), a fourth water-blocking unit (50), a fifth water-blocking unit (60) and a sixth water-blocking unit (70) which are uniformly arranged along the circumferential direction of the cable body (10); The cable body (10) comprises a protective layer (14), an inner extrusion package of the protective layer (14) is provided with a shielding layer (13), an outer extrusion package of the protective layer (14) is provided with a water-blocking layer (15), the water-blocking component is embedded in the protective layer (14), and a water-blocking groove (18) matching the water-blocking component is provided in the protective layer (14); The first water-blocking unit (20) comprises a water-blocking support seat (21) fixed inside the water-blocking groove (18) on a side close to the shielding layer (13), and also comprises a first cement support layer (22) and a second cement support layer (23) fixed inside the water-blocking groove (18) on a side close to the water-blocking layer (15), the first cement support layer (22) and the second cement support layer (23) being arranged at intervals, the first cement support layer (22) and the second cement support layer (23) being wrapped around the outside of the SAP water-absorbing layer (24), and a first water-blocking section (25) arranged between the first cement support layer (22) and the second cement support layer (23) being integrally formed on the SAP water-absorbing layer (24), and a second water-blocking section (26) arranged between the water-blocking support seat (21) and the first cement support layer (22) being integrally formed on the SAP water-absorbing layer (24).

2. The rail transit composite water-blocking cable according to claim 1, characterized in that: The first water-blocking unit (20), the second water-blocking unit (30), the third water-blocking unit (40), the fourth water-blocking unit (50), the fifth water-blocking unit (60) and the sixth water-blocking unit (70) have the same structure, and a hydrogel water-absorbing layer (28) is filled between each group of the SAP water-absorbing layer (24) and the water-blocking support seat (21).

3. The rail transit composite water-blocking cable according to claim 2 is characterized in that: A pressurized air bag (29) is arranged at the center of the hydrogel water-absorbing layer (28), two adjacent groups of pressurized air bags (29) are connected via a pressure relief air pipe (210), and a pressure relief valve is fixedly mounted on each group of pressure relief air pipes (210).

4. The rail transit composite water-blocking cable according to claim 3 is characterized in that: The hydrogel water-absorbing layer (28) is composed of a non-woven bag and hydrogel, and the non-woven bag is filled with hydrogel, and the size of the hydrogel water-absorbing layer (28) matches the size of the water-blocking groove (18), and the pressurized air bag (29) is elliptical, and the length of the pressurized air bag (29) is the same as the length of the water-blocking groove (18).

5. The rail transit composite water-blocking cable according to claim 4, characterized in that: The first water-isolating section (25) and the second water-isolating section (26) are both in the shape of strips; the SAP water-absorbing layer (24) is embedded with a meandering electric heating wire (27); the electric heating wire (27) runs through the second water-isolating section (26), the SAP water-absorbing layer (24) and the first water-isolating section (25); and the SAP water-absorbing layer (24) is embedded with conductive terminals corresponding to the two ends of the electric heating wire (27).

6. The rail transit composite water-blocking cable according to claim 1, characterized in that: The cable body (10) further comprises a core conductor (11) at the center, the outer wall of the core conductor (11) is extruded with an insulating sheath (12), and the insulating sheath (12) is arranged on the inner side of the shielding layer (13), the outer wall of the water-blocking layer (15) is extruded with a flame retardant layer (16), and the outer wall of the flame retardant layer (16) is extruded with an outer sheath (17).

7. The rail transit composite water-blocking cable according to claim 6, characterized in that: The top of the water-blocking groove (18) is in contact with the water-blocking layer (15), the bottom of the water-blocking groove (18) is in contact with the shielding layer (13), and the water-blocking support seat (21) is an arched reinforcement seat in contact with the inner side wall of the water-blocking groove (18).

8. A water blocking device, characterized in that: The water-blocking device comprises a plurality of groups of water-blocking components, and the water-blocking components are arranged linearly along the length direction of the cable body (10).

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