Self-checking acid and alkali resistant nuclear cable

Abstract

The invention relates to the technical field of cables, in particular to a self-checking acid and alkali resistant nuclear cable which comprises conductors, double-layer insulation, a polyimide tape layer, a filling layer, a waterproof inner sheath and an outer sheath. The waterproof inner sheath and the waterproof outer sheath are made of acid and alkali resistant fluororubber materials, and can cope with long-term soaking of strong acid and alkali solutions under extreme accidents of a nuclear power station; through the combined design of double-layer insulation and the polyimide tape layer, the radiation resistance, high temperature resistance and flame retardance of the cable are improved, and the special working condition requirements of the nuclear power station are met; through the synergistic effect of the built-in diversion monitoring pipe, the external diversion monitoring pipe and the magnetic control reciprocating diversion pump, in cooperation with the temperature and humidity sensor and the pressure sensor, temperature, humidity and pressure state parameters in the cable can be monitored in real time, so that the running state of the cable is judged, the internal heat dissipation effect of the cable is enhanced, and when the parameters exceed a preset threshold value, the cable is protected. Early warning signals can be sent to an external monitoring terminal in time, so that workers can check hidden dangers in time, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and in particular to a self-testing acid and alkali resistant nuclear cable. Background Technology

[0002] With the advancement of technology, nuclear power plants, as a clean and renewable energy source, have developed rapidly. In the initial design of nuclear power plants, to account for potential changes in operating conditions under extreme accidents, such as the highly acidic or alkaline solution environment caused by the rupture of high-energy and medium-energy pipelines, cables need to withstand long-term immersion in such environments to maintain power supply functionality in the short term following a nuclear accident, ensuring the normal operation of related instruments and meters.

[0003] In the existing technology, there have been relevant studies on this problem, but there are still very obvious defects. For example, patent CN103578660A discloses a manufacturing method for low-voltage power cables used in the containment of third-generation nuclear power plants. The insulation and sheath materials are selected from polymer materials with a thermal life of more than 60 years to meet the requirements of long-term heat resistance and irradiation aging. However, the sheath material of this cable has insufficient acid and alkali resistance and cannot cope with long-term immersion in strong acid and alkali solutions under extreme accidents.

[0004] In addition, existing nuclear power plant cables are simply passively protected by external protective structures. During use, they cannot self-inspect the condition of the cables themselves or the deformation that occurs, resulting in limited functionality and intelligence. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the existing cables used in nuclear power plants have insufficient acid and alkali resistance and only rely on simple external protective structures for passive protection. During use, they cannot perform self-inspection on the condition of the cable itself and the deformation, resulting in limited functionality and intelligence.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a self-testing acid and alkali resistant nuclear cable, comprising a conductor, double insulation, a polyimide tape layer, a filler layer, a waterproof inner sheath, and an outer sheath.

[0007] The conductor is composed of seven 0.68mm tinned copper wires twisted together, with a twist ratio not exceeding 16. This structure improves the conductor's flexibility and conductivity stability, while the tin plating enhances its corrosion resistance. Double insulation is achieved by simultaneously extruding an inner and outer insulation layer onto the conductor using a double-layer extrusion unit and an extrusion die, forming an insulated core. The inner insulation layer uses a high-electrical-performance radiation-resistant material to ensure the cable's insulation performance and radiation resistance; the outer insulation layer uses a radiation-resistant, halogen-free, low-smoke flame-retardant material to improve the cable's flame retardancy and environmental friendliness.

[0008] A polyimide tape layer is wrapped around the outer insulation layer to further enhance the cable's radiation resistance and high-temperature resistance. A filler layer, made of halogen-free flame-retardant elastomer material, is extruded onto the outside of the stranded insulated cores to fill the gaps between them, improving the cable's roundness and structural stability. A waterproof inner sheath is extruded onto the outside of the filler layer, and an outer sheath is extruded onto the outer periphery of the waterproof inner sheath. Both the waterproof inner and outer sheaths are made of acid and alkali-resistant fluororubber material, capable of withstanding immersion in strong acid and alkali solutions under extreme conditions.

[0009] An internal current-conducting monitoring tube is installed inside the insulated core. The inner arc-shaped surface of the internal current-conducting monitoring tube has inwardly protruding heat-conducting fins that fit against the outer wall of the insulated core to conduct heat generated during operation. An external current-conducting monitoring tube is installed between the filling layer and the waterproof inner sheath. A magnetically controlled reciprocating current-conducting pump is installed at the end of the internal current-conducting monitoring tube. The outer end of the magnetically controlled reciprocating current-conducting pump is fixedly connected to the external current-conducting monitoring tube via a rigid shunt.

[0010] The magnetically controlled reciprocating flow pump includes a piston housing, a control piston, a temperature and humidity sensor, a pressure sensor, an embedded electromagnet, an external control spring, an internal control spring, and a side sealing block. The piston housing is axially fixed to the end of a built-in flow monitoring tube, with the other end connected to an external flow monitoring tube via a rigid flow divider. The interior is filled with insulating and thermally conductive silicone oil. The control piston is slidably mounted inside the piston housing, and the embedded electromagnet is fixed inside the control piston. The two ends of the external control spring are connected to the inner wall of the piston housing and the side wall of the control piston, respectively. The opening and closing of the embedded electromagnet controls the extension and retraction of the external control spring, driving the control piston to reciprocate.

[0011] The control piston has a lateral adjustment groove on its outer side. An internal control spring and a lateral sealing block are installed in the groove. The lateral sealing block is connected to an embedded electromagnet via the internal control spring. The embedded electromagnet drives the internal control spring to extend and retract, controlling the sliding of the lateral sealing block. Side-mounted guide holes communicating with the lateral adjustment groove are located on both sides of the control piston. The lateral sealing block can open or close these guide holes. Temperature and humidity sensors and pressure sensors are installed at both ends of the control piston and electrically connected to an external monitoring terminal for real-time monitoring of the temperature, humidity, and pressure parameters inside the cable.

[0012] The beneficial effects of this invention are: (1) The waterproof inner and outer sheaths of the present invention are made of acid and alkali resistant fluororubber materials, which can withstand long-term immersion in strong acid and alkali solutions under extreme accidents in nuclear power plants; the combination design of double insulation and polyimide tape layer improves the radiation resistance, high temperature resistance and flame retardant performance of the cable, and meets the special working conditions of nuclear power plants. (2) Through the synergistic effect of the built-in flow monitoring tube, the external flow monitoring tube and the magnetically controlled reciprocating flow pump, combined with the temperature and humidity sensor and the pressure sensor, the temperature, humidity and pressure parameters inside the cable can be monitored in real time, thereby judging the operating status of the cable and enhancing the internal heat dissipation effect of the cable. When the parameters exceed the preset threshold, an early warning signal can be sent to the external monitoring terminal in a timely manner, which is convenient for staff to check for hidden dangers in a timely manner and reduce maintenance costs. (3) The conductor adopts a structure of 7 tinned copper wires stranded together, and the filler layer adopts halogen-free flame-retardant elastomer material, which can improve the flexibility and roundness of the cable and avoid problems such as breakage and deformation during the laying or use of the cable; the design of the heat-conducting fins can conduct the heat generated by the insulated core in time, and prevent local overheating from affecting the service life of the cable. (4) The magnetically controlled reciprocating flow pump achieves automated control through embedded electromagnets, eliminating the need for manual intervention. It enables integrated operation of flow diversion and monitoring, improving the intelligence level of the cable and ensuring the stable operation of related instruments and meters in the nuclear power plant. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Figure 1 This is a cross-sectional view of the central part of the present invention.

[0015] Figure 2 This is a cross-sectional view of the end position of the present invention.

[0016] Figure 3 This is a schematic diagram of the structure of the magnetically controlled reciprocating flow pump and the rigid flow divider in this invention.

[0017] Figure 4 This is an exploded schematic diagram of the magnetically controlled reciprocating flow pump and the rigid flow divider in this invention.

[0018] Figure 5 This is a schematic diagram of the internal structure of the control piston in this invention.

[0019] In the diagram: 1. Conductor; 2. Inner insulation layer; 3. Outer insulation layer; 4. Polyimide tape layer; 5. Filler layer; 6. Waterproof inner sheath; 7. Outer sheath; 8. Built-in flow monitoring tube; 9. External flow monitoring tube; 10. Magnetically controlled reciprocating flow pump; 11. Rigid flow divider; 12. Thermal fins; 101. Piston housing; 102. Control piston; 103. Temperature and humidity sensor; 104. Pressure sensor; 105. Embedded electromagnet; 106. External control spring; 107. Internal control spring; 108. Side sealing block; 109. Side adjustment groove; 110. Side flow guide hole. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figures 1 to 5 The self-testing acid and alkali resistant nuclear power cable shown includes a conductor 1, an inner insulation layer 2, an outer insulation layer 3, a polyimide tape layer 4, a filler layer 5, a waterproof inner sheath 6, and an outer sheath 7. The conductor 1 is composed of seven 0.68mm tinned copper wires twisted together with a twist ratio of 15. After twisting, the wires are shaped using a wire bundling machine. The inner insulation layer 2 is made of high-electrical-performance radiation-resistant cross-linked polyethylene material, and the outer insulation layer 3 is made of radiation-resistant halogen-free, low-smoke, flame-retardant polyolefin material. These materials are simultaneously extruded onto the outside of the conductor 1 using a double-layer extrusion die, with the extrusion temperature controlled at 120℃-140℃, forming the insulated core.

[0023] The polyimide tape layer 4 is wrapped around the outside of the outer insulation layer 3 using a semi-overlapping wrapping method, with the wrapping tension controlled at 50N-80N. The filler layer 5 is made of halogen-free flame-retardant elastomer material and is extruded around the outside of the stranded insulated cores. The thickness of the filler layer 5 is 1.5mm-2.0mm, used to fill the gaps between the insulated cores. Both the waterproof inner sheath 6 and the outer sheath 7 are made of acid and alkali resistant fluororubber material. The waterproof inner sheath 6 is extruded around the outside of the filler layer 5, with a thickness of 2.0mm-2.5mm; the outer sheath 7 is extruded around the outside of the waterproof inner sheath 6, with a thickness of 2.5mm-3.0mm. The cooling temperature for both extrusions is controlled at 25℃-30℃.

[0024] The built-in current-guiding monitoring tube 8 is made of high-temperature resistant polytetrafluoroethylene and is located inside the insulated wire core. Heat-conducting fins 12 are integrally formed on the inner arc-shaped surface of the built-in current-guiding monitoring tube 8, and the heat-conducting fins 12 are tightly fitted to the outer wall of the insulated wire core. The external current-guiding monitoring tube 9 is made of the same material as the built-in current-guiding monitoring tube 8 and is located between the filling layer 5 and the waterproof inner sheath 6. The piston housing 101 of the magnetically controlled reciprocating current-guiding pump 10 is axially fixed to the end of the built-in current-guiding monitoring tube 8. The piston housing 101 is filled with insulating and heat-conducting silicone oil, and the other end of the piston housing 101 is fixedly connected to the external current-guiding monitoring tube 9 through a rigid flow divider 11.

[0025] The control piston 102 is slidably mounted inside the piston housing 101. The embedded electromagnet 105 is fixed inside the control piston 102 by bolts. The two ends of the external control spring 106 are welded to the inner wall of the piston housing 101 and the side wall of the control piston 102, respectively. A lateral adjustment groove 109 is provided on the outer side of the control piston 102. The internal control spring 107 and the lateral sealing block 108 are both installed inside the lateral adjustment groove 109. The lateral sealing block 108 is connected to the embedded electromagnet 105 through the internal control spring 107. Lateral guide holes 110 are provided on both sides of the control piston 102. The lateral guide holes 110 are connected to the inside of the lateral adjustment groove 109. The lateral sealing block 108 can slide along the lateral adjustment groove 109 under the drive of the internal control spring 107, realizing the opening or closing of the lateral guide holes 110.

[0026] Temperature and humidity sensors 103 are embedded at both ends of the control piston 102, and pressure sensors 104 are fixed to the end faces of both ends of the control piston 102 with screws. Both temperature and humidity sensors 103 and pressure sensors 104 are electrically connected to an external monitoring terminal via wires. When the cable is working, the heat generated by the insulated core is transferred through the heat-conducting fins 12 to the heat-conducting medium in the built-in flow-guiding monitoring tube 8. The heat-conducting medium can be air or insulating heat-conducting silicone oil. When the embedded electromagnet 105 is energized, it generates magnetic force, driving the external control spring 106 to contract, causing the control piston 102 to slide inside the piston housing 101. At the same time, the embedded electromagnet 105 drives the internal control spring 107 to contract, causing the side sealing block 108 to slide and open the side flow-guiding hole 110. The heat-conducting medium moves from one end of the control piston 102 to the other end through the side flow-guiding hole 110. Then, after the embedded electromagnet 105 is de-energized, the external control spring 106 and the internal control spring 107 extend and reset, thereby controlling the entire control piston 102 and the side sealing block 108 to slide and reset, thus allowing the medium inside the rigid diverter 11 to flow into the built-in flow monitoring tube 8. The control pistons 102 at both ends of the built-in flow monitoring tube 8 run in opposite directions. One end of the control piston 102 controls the medium to flow from the external flow monitoring tube 9 into the built-in flow monitoring tube 8, while the other end of the control piston 102 controls the medium to flow from the built-in flow monitoring tube 8 into the external flow monitoring tube 9, thereby realizing the conduction and circulation of heat.

[0027] Temperature and humidity sensor 103 and pressure sensor 104 collect real-time temperature, humidity, and pressure data inside the cable and transmit them to an external monitoring terminal. When the medium is air, the cable breakage can be determined by the humidity sensor, and the cable breakage or bending status can be determined by the change in pressure values ​​on both sides of the piston 102 during its movement. When the data exceeds a preset threshold, the monitoring terminal issues an early warning signal, allowing personnel to promptly inspect and repair the cable. After the embedded electromagnet 105 is de-energized, the external control spring 106 and internal control spring 107 reset, and the lateral sealing block 108 closes the side guide hole 110, stopping the flow circulation.

[0028] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A self-testing acid and alkali resistant nuclear cable, comprising a conductor (1), double insulation, a polyimide tape layer (4), a filler layer (5), a waterproof inner sheath (6), and an outer sheath (7), characterized in that: The conductor (1) is made of 7 strands of 0.68mm tin-plated copper wires twisted together, with a twisting pitch ratio not greater than 16; The double insulation is formed by extruding an inner insulation layer (2) and an outer insulation layer (3) onto the conductor (1) to form an insulated core. The polyimide tape layer (4) is wrapped around the outside of the outer insulation layer (3); The filler layer (5) and the waterproof inner sheath (6) are extruded onto the outside of the stranded insulated core. The outer sheath (7) is extruded onto the outer periphery of the waterproof inner sheath (6); An internal current-conducting monitoring tube (8) is provided on the inner side of the insulated wire core. An external current-conducting monitoring tube (9) is provided between the filling layer (5) and the waterproof inner sheath (6). A magnetically controlled reciprocating current-conducting pump (10) is provided at the end of the internal current-conducting monitoring tube (8). The outer end of the magnetically controlled reciprocating current-conducting pump (10) is fixedly connected to the external current-conducting monitoring tube (9) through a rigid shunt (11).

2. The self-testing acid and alkali resistant nuclear power cable according to claim 1, characterized in that: The inner insulation layer (2) is made of high electrical performance radiation resistant material, and the outer insulation layer (3) is made of radiation resistant halogen-free low smoke flame retardant material. The inner insulation layer (2) and the outer insulation layer (3) are extruded onto the conductor (1) simultaneously using a double-layer extrusion unit and an extrusion die.

3. The self-testing acid and alkali resistant nuclear power cable according to claim 1, characterized in that: The filler layer (5) is made of halogen-free flame-retardant elastomer material.

4. A self-testing acid and alkali resistant nuclear power cable according to claim 1, characterized in that: The built-in flow monitoring tube (8) has inwardly protruding heat-conducting fins (12) on its inner arc-shaped surface.

5. A self-testing acid and alkali resistant nuclear power cable according to claim 1, characterized in that: The magnetically controlled reciprocating flow pump (10) includes a piston housing (101), a control piston (102), a temperature and humidity sensor (103), an embedded electromagnet (105), an external control spring (106), an internal control spring (107), and a lateral sealing block (108).

6. A self-testing acid and alkali resistant nuclear power cable according to claim 5, characterized in that: The piston housing (101) is axially fixed to the end of the built-in flow monitoring tube (8), and the other end of the piston housing (101) is fixedly connected to the external flow monitoring tube (9) through a rigid flow divider (11).

7. A self-testing acid and alkali resistant nuclear power cable according to claim 5, characterized in that: The control piston (102) is slidably installed inside the piston housing (101), and the embedded electromagnet (105) is fixedly installed inside the control piston (102). The two ends of the external control spring (106) are respectively connected to the inner wall of the piston housing (101) and the side wall of the control piston (102). The external control spring (106) is controlled to contract by opening and closing the embedded electromagnet (105), thereby driving the control piston (102) to slide and adjust inside the piston housing (101).

8. A self-testing acid and alkali resistant nuclear power cable according to claim 5, characterized in that: The outer surface of the control piston (102) is provided with a lateral adjustment groove (109) for installing an internal control spring (107) and a lateral sealing block (108). The lateral sealing block (108) is connected to an embedded electromagnet (105) through the internal control spring (107). The embedded electromagnet (105) controls the lateral sealing block (108) to slide and adjust inside the lateral adjustment groove (109) by opening and closing the internal control spring (107).

9. A self-testing acid and alkali resistant nuclear power cable according to claim 8, characterized in that: The control piston (102) has side guide holes (110) on both sides that are connected to the interior of the side adjustment groove (109).

10. A self-testing acid and alkali resistant nuclear power cable according to claim 5, characterized in that: The temperature and humidity sensor (103) is embedded and fixed at both ends of the control piston (102), and pressure sensors (104) are fixedly installed at both ends of the control piston (102).

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