Anti-ablation structure, high-voltage cable and extrusion process of anti-ablation structure

Abstract

The invention discloses an anti-ablation structure, a high-voltage cable and an extrusion process of the anti-ablation structure, the anti-ablation structure comprises a TPU material layer arranged on the outer surface of an insulated wire core, and the TPU material layer wraps the insulated wire core. The anti-ablation method comprises the step of extruding the TPU material layer on the outer surface of the insulated wire core to form the physical isolation layer. The high-voltage cable with the anti-ablation structure comprises an insulating wire core, the insulating wire core is wrapped with the anti-ablation structure, the anti-ablation structure is a TPU material layer, the TPU material layer is wrapped with a composite water-blocking buffer layer, and the composite water-blocking buffer layer is sequentially provided with a water-absorbing fiber layer and a hydrophobic expansion water-blocking tape from inside to outside. The TPU material layer is wrapped outside the insulating wire core of the high-voltage cable, so that a physical isolation layer is formed between the insulating wire core and the aluminum sleeve, an electrochemical corrosion path is blocked, and electric field distribution is uniform; the TPU material layer is wrapped with the composite water-blocking buffer layer, interface moisture can be rapidly absorbed, the composite water-blocking buffer layer swells when encountering water to seal holes, and the whole body is prevented from being affected with damp.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage cable manufacturing, in particular to an anti-ablation structure, a high-voltage cable and an extrusion process of the anti-ablation structure. Background Art

[0002] Ablation will reduce the conductivity of high-voltage cables and increase resistance. The increased resistance will cause the high-voltage cables to generate more heat when transmitting current, further aggravating the degree of ablation, forming a vicious circle, which may eventually cause the cables to be unable to transmit electricity normally, affecting the stability and reliability of power supply.

[0003] Existing high-voltage cables mostly use a single water-blocking buffer belt structure, which has the following defects:

[0004] 1. The resistivity exceeds the standard when it is damp: The volume resistivity of the water-blocking buffer zone decreases after it is damp, resulting in poor contact between the insulating shielding layer and the aluminum sleeve, forming a local high-resistance area;

[0005] 2. Electrochemical corrosion: The water-blocking powder in the buffer layer reacts electrochemically with the aluminum sleeve, exacerbating the deterioration of the contact interface;

[0006] 3. Local overheating and ablation: The high-resistance area generates Joule heat during operation, ablating the semi-conductive insulation shielding layer and eventually leading to main insulation breakdown.

[0007] Traditional solutions only alleviate the problem by improving the buffer zone material or increasing the thickness, but fail to systematically address the ablation risk from dimensions such as structural synergy, interface corrosion protection, and process controllability. Summary of the invention

[0008] The purpose of the present invention is to provide an anti-ablation structure, a high-voltage cable and an extrusion process for the anti-ablation structure, aiming to improve the problem that the existing high-voltage cable adopts a single water-blocking buffer belt structure, which easily forms local high-resistance areas, aggravates contact interface degradation and causes local overheating and ablation.

[0009] The present invention is achieved in that:

[0010] According to a first aspect of the present invention, the present invention provides an anti-ablation structure for a high-voltage cable having an insulating core; the anti-ablation structure comprises a TPU material layer arranged on the outer surface of the insulating core, and the TPU material layer wraps the insulating core.

[0011] According to a second aspect of the present invention, the present invention provides an anti-ablation method for a high-voltage cable having an insulating cable core. The anti-ablation method includes extruding a TPU material layer on the outer surface of the insulating core to form a physical isolation layer.

[0012] According to a third aspect of the present invention, the present invention provides a high-voltage cable with an anti-ablation structure, comprising an insulating core, wherein the insulating core is wrapped with the anti-ablation structure, and the anti-ablation structure is a TPU material layer.

[0013] Preferably, the TPU material layer is wrapped with a composite water-blocking buffer layer, and the composite water-blocking buffer layer comprises a water-absorbing fiber layer and a hydrophobic swelling water-blocking tape from the inside to the outside.

[0014] Preferably, the surface of the TPU material layer is molded with spiral protrusions with a pitch of 5 to 10 mm and a height of 1 to 2 mm. The composite water-blocking buffer layer is made of glass fiber felt and acrylate water-blocking tape through double-layer winding, and the surface of the composite water-blocking buffer layer has a spiral protrusion structure.

[0015] Preferably, the outer side of the composite water-blocking buffer layer is wrapped with a corrugated aluminum sleeve, an anti-corrosion asphalt layer, an outer sheath and an extruded semi-conductive layer in sequence from the inside to the outside, the inner wall of the corrugated aluminum sleeve is provided with a zinc coating or coated with a conductive anti-corrosion coating, and conductive silicone grease is filled between the composite water-blocking buffer layer and the corrugated aluminum sleeve, and the volume resistivity of the conductive silicone grease is ≤103Ω·cm.

[0016] Preferably, the insulating core comprises, from inside to outside, a cable conductor, a conductor shielding layer, an insulating layer and an insulating shielding layer.

[0017] Preferably, the cable conductor is made of copper or aluminum, the conductor shielding layer is made of polyethylene as the base material with conductive fillers added, the insulating layer is made of cross-linked polyethylene or EPDM rubber material, and the insulating shielding layer is made of base resin with conductive fillers, cross-linking agents and antioxidants added.

[0018] According to a fourth aspect of the present invention, the present invention provides an extrusion process of an anti-ablation structure of a high-voltage cable, wherein the anti-ablation structure of the high-voltage cable comprises a TPU material layer wrapped around the outside of an insulating core, and the specific process steps are as follows:

[0019] S100, raw material pretreatment, drying the TPU raw material to reduce its water content to below 0.05%;

[0020] S200, melt and extrude the TPU raw material onto the outside of the insulating wire core through an extruder at a set extrusion temperature and extrusion pressure to form a TPU material layer; and the TPU material layer is vulcanized in three stages using a gradient vulcanization process to improve the interlayer bonding strength;

[0021] S300, molding spiral protrusions on the surface of the TPU material layer.

[0022] Preferably, in the step S100, the TPU raw material is placed in an oven and heated and dried at a temperature of 85-95°C for 11-13 hours; in the step S200, the extruder uses a twin-screw extruder, the extrusion temperature is 180-220°C, and the extrusion pressure is 5-10MPa; the extruder uses an extruder with a screw length-to-diameter ratio of 16-20 and a compression ratio of 2.0-2.5; during the first stage of vulcanization, the vulcanization temperature is 140-160°C, and the vulcanization time is 25-35min; during the second stage of vulcanization, the vulcanization temperature is 175-185°C, and the vulcanization time is 15-25min; during the third stage of vulcanization, the vulcanization temperature is 125-135°C, and the vulcanization time is 50-70min.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention wraps a TPU material layer outside the insulating core of the high-voltage cable, so that a physical isolation layer is formed between the insulating core and the aluminum sheath, blocking the electrochemical corrosion path and uniformly distributing the electric field.

[0025] 2. The outside of the TPU material layer is wrapped with a composite water-blocking buffer layer, which can quickly absorb moisture from the interface, swell and seal the pores when it encounters water, and prevent the whole from being damp through the synergistic effect of water absorption and water repellency. The surface of the TPU material layer is molded with spiral protrusions, which can make the surface of the composite water-blocking buffer layer have a spiral protrusion structure. The spiral protrusion structure can effectively increase the water penetration path and enhance the water-blocking effect without increasing the thickness of the composite water-blocking buffer layer too much.

[0026] 3. The inner wall of the corrugated aluminum sleeve of the present invention is provided with a zinc coating or coated with a conductive anti-corrosion coating, which can effectively block the electrochemical corrosion of aluminum-water-blocking powder. Conductive silicone grease is filled between the composite water-blocking buffer layer and the corrugated aluminum sleeve to ensure the continuity of electrical contact.

[0027] 4. The present invention provides an extrusion process for a high-voltage cable anti-ablation structure, which effectively improves the interlayer bonding strength through a gradient vulcanization process. The extruder with a screw length-to-diameter ratio of 16-20 and a compression ratio of 2.0-2.5 can reduce the damage of high shear force to the physical properties of TPU to a certain extent, ensuring the stability of the processing process and good product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional schematic diagram of a high-voltage cable with an anti-ablation structure provided by the present invention.

[0029] In the figure: 1. Cable conductor; 2. Conductor shielding layer; 3. Insulation layer; 4. Insulation shielding layer; 5. TPU material layer; 6. Composite water-blocking buffer layer; 7. Spiral raised structure; 8. Corrugated aluminum sheath; 9. Anti-corrosion asphalt layer; 10. Outer sheath; 11. Extruded semi-conductive layer. DETAILED DESCRIPTION

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The following is a further description with reference to the accompanying drawings and specific embodiments:

[0032] Example 1

[0033] A high voltage cable with an ablation-resistant structure, such as Figure 1 As shown, it includes an insulating core, and the insulating core is composed of a cable conductor 1, a conductor shielding layer 2, an insulating layer 3 and an insulating shielding layer 4 from the inside to the outside. The cable conductor 1 is made of copper or aluminum, the conductor shielding layer 2 is made of polyethylene as a base material and a conductive filler is added, and the conductive filler can use carbon black, the insulating layer 3 is made of cross-linked polyethylene or ethylene propylene rubber material, and the insulating shielding layer 4 is made of a base resin with a conductive filler, a cross-linking agent and an antioxidant. The cross-linking agent can use diisopropylbenzene peroxide, a silane cross-linking agent, etc. The addition of the cross-linking agent can form chemical bonds between polymer molecular chains, and transform linear or branched polymer molecules into a three-dimensional network structure, which can improve the heat resistance, mechanical strength, chemical corrosion resistance and water resistance of the material. The antioxidant can use a hindered phenol antioxidant to prevent or delay the performance degradation of the high-voltage cable due to oxidation during use.

[0034] like Figure 1 As shown, the insulating core of the high-voltage cable is wrapped with an anti-ablation structure, and the anti-ablation structure is a TPU material layer 5, forming a physical isolation layer. The TPU material layer 5 has high elasticity and a wide applicable temperature range of -40°C to 120°C, and is resistant to both low and high temperatures. In addition, the TPU material layer 5 has a stable resistivity characteristic (108 to 1010Ω·cm), forming a physical isolation layer that can effectively block the electrochemical corrosion path and evenly distribute the electric field. The TPU material layer 5 is extruded outside the insulating core, and its specific extrusion process includes the following steps:

[0035] S100, raw material pretreatment, put the TPU raw material into an oven, heat and dry it at 85℃ for 13 hours, and reduce its water content to below 0.05%. TPU raw material has the characteristics of easy moisture absorption and hydrolysis, which will affect the subsequent processing performance and product quality of TPU, so it must be dried before processing to ensure the smooth progress of subsequent processing.

[0036] S200, melt and extrude the TPU raw material onto the outside of the insulating wire core through a twin-screw extruder at a set extrusion temperature and extrusion pressure to form a TPU material layer 5. The TPU material has a high viscosity when in a molten state, and is prone to high shear force when flowing in the material tube. This high shear force will destroy the physical properties of the TPU itself. Based on this, when selecting an extruder, a twin-screw extruder with a screw length-to-diameter ratio of 16 and a compression ratio of 2.0 is selected. Such extruder parameter settings can reduce the damage of high shear force to the physical properties of TPU to a certain extent, ensuring the stability of the processing process and good product performance. The extrusion temperature of the extruder during extrusion is 180°C, the extrusion pressure is 10MPa, and an impedance monitoring device with a frequency of 1kHz to 1MHz is set to adjust the extrusion temperature and extrusion pressure in real time. The TPU material layer 5 uses a gradient vulcanization process and is vulcanized in three stages. In the first stage, the vulcanization temperature is 140°C and the vulcanization time is 35 minutes; in the second stage, the vulcanization temperature is 175°C and the vulcanization time is 25 minutes; in the third stage, the vulcanization temperature is 125°C and the vulcanization time is 70 minutes. This can effectively improve the interlayer bonding strength.

[0037] S300, a spiral protrusion is molded on the surface of the TPU material layer 5, with a pitch of 5 mm and a height of 1 mm, so as to increase the contact area, reduce the contact resistance, and provide mechanical buffering.

[0038] like Figure 1 As shown, the TPU material layer 5 is wrapped with a composite water-blocking buffer layer 6, and the composite water-blocking buffer layer 6 is composed of a water-absorbing fiber layer and a hydrophobic swelling water-blocking tape from the inside to the outside. The composite water-blocking buffer layer 6 is made of glass fiber felt and acrylate water-blocking tape through double-layer winding. Since the surface of the TPU material layer 5 is molded with spiral protrusions, the surface of the composite water-blocking buffer layer 6 can have a spiral protrusion structure 7. The spiral protrusion structure 7 can effectively increase the water penetration path and enhance the water-blocking effect without increasing the thickness of the composite water-blocking buffer layer 6 too much.

[0039] like Figure 1 As shown, the outer side of the composite water-blocking buffer layer 6 is wrapped with a corrugated aluminum sleeve 8, an anti-corrosion asphalt layer 9, an outer sheath 10 and an extruded semi-conductive layer 11 in sequence from the inside to the outside. The inner wall of the corrugated aluminum sleeve 8 is provided with a zinc coating or coated with a conductive anti-corrosion coating. The conductive anti-corrosion coating can use graphene-modified epoxy resin, which can effectively block the electrochemical corrosion of aluminum-water-blocking powder. Conductive silicone grease is filled between the composite water-blocking buffer layer 6 and the corrugated aluminum sleeve 8 to ensure the continuity of electrical contact. The volume resistivity of the conductive silicone grease is ≤10 3 The extruded semiconductive layer 11 has the functions of uniform electric field and providing a fault current path, which can effectively improve the insulation performance and operation safety of the high-voltage cable.

[0040] Example 2

[0041] A high voltage cable with an ablation-resistant structure, such as Figure 1 As shown, it includes an insulating core, and the insulating core is composed of a cable conductor 1, a conductor shielding layer 2, an insulating layer 3 and an insulating shielding layer 4 from the inside to the outside. The cable conductor 1 is made of copper or aluminum, the conductor shielding layer 2 is made of polyethylene as a base material and a conductive filler is added, and the conductive filler can use carbon black, the insulating layer 3 is made of cross-linked polyethylene or ethylene propylene rubber material, and the insulating shielding layer 4 is made of a base resin with a conductive filler, a cross-linking agent and an antioxidant. The cross-linking agent can use diisopropylbenzene peroxide, a silane cross-linking agent, etc. The addition of the cross-linking agent can form chemical bonds between polymer molecular chains, and transform linear or branched polymer molecules into a three-dimensional network structure, which can improve the heat resistance, mechanical strength, chemical corrosion resistance and water resistance of the material. The antioxidant can use a hindered phenol antioxidant to prevent or delay the performance degradation of the high-voltage cable due to oxidation during use.

[0042] like Figure 1 As shown, the insulating core of the high-voltage cable is wrapped with an anti-ablation structure, and the anti-ablation structure is a TPU material layer 5, forming a physical isolation layer. The TPU material layer 5 has high elasticity and a wide applicable temperature range of -40°C to 120°C, and is resistant to both low and high temperatures. In addition, the TPU material layer 5 has a stable resistivity characteristic (108 to 1010Ω·cm), forming a physical isolation layer that can effectively block the electrochemical corrosion path and evenly distribute the electric field. The TPU material layer 5 is extruded outside the insulating core, and its specific extrusion process includes the following steps:

[0043] S100, raw material pretreatment, put the TPU raw material into an oven, heat and dry it at 90℃ for 12 hours, and reduce its water content to below 0.05%. TPU raw material has the characteristics of easy moisture absorption and hydrolysis, which will affect the subsequent processing performance and product quality of TPU, so it must be dried before processing to ensure the smooth progress of subsequent processing.

[0044] S200, melt and extrude the TPU raw material onto the outside of the insulating wire core through a twin-screw extruder at a set extrusion temperature and extrusion pressure to form a TPU material layer 5. The TPU material has a high viscosity when it is molten, and it is easy to generate high shear force when it flows in the material tube. This high shear force will destroy the physical properties of the TPU itself. Based on this, when selecting an extruder, a twin-screw extruder with a screw length-to-diameter ratio of 18 and a compression ratio of 2.3 is selected. Such extruder parameter settings can reduce the damage of high shear force to the physical properties of TPU to a certain extent, ensuring the stability of the processing process and good product performance. The extrusion temperature of the extruder during extrusion is 195°C, the extrusion pressure is 8MPa, and an impedance monitoring device with a frequency of 1kHz to 1MHz is set to adjust the extrusion temperature and extrusion pressure in real time. The TPU material layer 5 uses a gradient vulcanization process and is vulcanized in three stages. In the first stage, the vulcanization temperature is 150°C and the vulcanization time is 30 minutes; in the second stage, the vulcanization temperature is 180°C and the vulcanization time is 20 minutes; in the third stage, the vulcanization temperature is 130°C and the vulcanization time is 60 minutes, which can effectively improve the interlayer bonding strength.

[0045] S300, a spiral protrusion is molded on the surface of the TPU material layer 5, with a pitch of 8 mm and a height of 1.5 mm, so as to increase the contact area, reduce the contact resistance, and provide mechanical buffering.

[0046] like Figure 1 As shown, the TPU material layer 5 is wrapped with a composite water-blocking buffer layer 6, which is composed of a water-absorbent fiber layer and a hydrophobic swelling water-blocking tape from the inside to the outside, and can quickly absorb moisture from the interface, and swell and seal the pores when it encounters water, and prevent the whole from being damp through the synergistic effect of absorption / hydrophobicity. The composite water-blocking buffer layer 6 is made of glass fiber felt and acrylate water-blocking tape through double-layer winding. Since the surface of the TPU material layer 5 is molded with spiral protrusions, the surface of the composite water-blocking buffer layer 6 can have a spiral protrusion structure 7. The spiral protrusion structure 7 can effectively increase the water penetration path and enhance the water-blocking effect without increasing the thickness of the composite water-blocking buffer layer 6 too much.

[0047] like Figure 1 As shown, the outer side of the composite water-blocking buffer layer 6 is wrapped with a corrugated aluminum sleeve 8, an anti-corrosion asphalt layer 9, an outer sheath 10 and an extruded semi-conductive layer 11 in sequence from the inside to the outside. The inner wall of the corrugated aluminum sleeve 8 is provided with a zinc coating or coated with a conductive anti-corrosion coating. The conductive anti-corrosion coating can use graphene-modified epoxy resin, which can effectively block the electrochemical corrosion of aluminum-water-blocking powder. Conductive silicone grease is filled between the composite water-blocking buffer layer 6 and the corrugated aluminum sleeve 8 to ensure the continuity of electrical contact. The volume resistivity of the conductive silicone grease is ≤10 3 The extruded semiconductive layer 11 has the functions of uniform electric field and providing a fault current path, which can effectively improve the insulation performance and operation safety of the high-voltage cable.

[0048] Example 3

[0049] A high voltage cable with an ablation-resistant structure, such as Figure 1 As shown, it includes an insulating core, and the insulating core is composed of a cable conductor 1, a conductor shielding layer 2, an insulating layer 3 and an insulating shielding layer 4 from the inside to the outside. The cable conductor 1 is made of copper or aluminum, the conductor shielding layer 2 is made of polyethylene as a base material and a conductive filler is added, and the conductive filler can use carbon black, the insulating layer 3 is made of cross-linked polyethylene or ethylene propylene rubber material, and the insulating shielding layer 4 is made of a base resin with a conductive filler, a cross-linking agent and an antioxidant. The cross-linking agent can use diisopropylbenzene peroxide, a silane cross-linking agent, etc. The addition of the cross-linking agent can form chemical bonds between polymer molecular chains, and transform linear or branched polymer molecules into a three-dimensional network structure, which can improve the heat resistance, mechanical strength, chemical corrosion resistance and water resistance of the material. The antioxidant can use a hindered phenol antioxidant to prevent or delay the performance degradation of the high-voltage cable due to oxidation during use.

[0050] like Figure 1 As shown, the insulating core of the high-voltage cable is wrapped with an anti-ablation structure, and the anti-ablation structure is a TPU material layer 5, forming a physical isolation layer. The TPU material layer 5 has high elasticity and a wide applicable temperature range of -40°C to 120°C, and is resistant to both low and high temperatures. In addition, the TPU material layer 5 has a stable resistivity characteristic (108 to 1010Ω·cm), forming a physical isolation layer that can effectively block the electrochemical corrosion path and evenly distribute the electric field. The TPU material layer 5 is extruded outside the insulating core, and its specific extrusion process includes the following steps:

[0051] S100, raw material pretreatment, put the TPU raw material into an oven, heat and dry it at 95℃ for 11 hours, and reduce its water content to below 0.05%. TPU raw material has the characteristics of easy moisture absorption and hydrolysis, which will affect the subsequent processing performance and product quality of TPU, so it must be dried before processing to ensure the smooth progress of subsequent processing.

[0052] S200, melt and extrude the TPU raw material onto the outside of the insulating wire core through a twin-screw extruder at a set extrusion temperature and extrusion pressure to form a TPU material layer 5. The TPU material has a high viscosity when it is molten, and it is easy to generate high shear force when it flows in the material tube. This high shear force will destroy the physical properties of the TPU itself. Based on this, when selecting an extruder, a twin-screw extruder with a screw length-to-diameter ratio of 20 and a compression ratio of 2.5 is selected. Such extruder parameter settings can reduce the damage of high shear force to the physical properties of TPU to a certain extent, ensuring the stability of the processing process and good product performance. The extrusion temperature of the extruder during extrusion is 220°C, the extrusion pressure is 5MPa, and an impedance monitoring device with a frequency of 1kHz to 1MHz is set to adjust the extrusion temperature and extrusion pressure in real time. The TPU material layer 5 uses a gradient vulcanization process and is vulcanized in three stages. In the first stage, the vulcanization temperature is 160°C and the vulcanization time is 25 minutes; in the second stage, the vulcanization temperature is 185°C and the vulcanization time is 15 minutes; in the third stage, the vulcanization temperature is 135°C and the vulcanization time is 50 minutes. This can effectively improve the interlayer bonding strength.

[0053] S300, a spiral protrusion is molded on the surface of the TPU material layer 5, with a pitch of 10 mm and a height of 2 mm, so as to increase the contact area, reduce the contact resistance, and provide mechanical buffering.

[0054] like Figure 1 As shown, the TPU material layer 5 is wrapped with a composite water-blocking buffer layer 6, and the composite water-blocking buffer layer 6 is composed of a water-absorbing fiber layer and a hydrophobic swelling water-blocking tape from the inside to the outside. The composite water-blocking buffer layer 6 is made of glass fiber felt and acrylate water-blocking tape through double-layer winding. Since the surface of the TPU material layer 5 is molded with spiral protrusions, the surface of the composite water-blocking buffer layer 6 can have a spiral protrusion structure 7. The spiral protrusion structure 7 can effectively increase the water penetration path and enhance the water-blocking effect without increasing the thickness of the composite water-blocking buffer layer 6 too much.

[0055] like Figure 1 As shown, the outer side of the composite water-blocking buffer layer 6 is wrapped with a corrugated aluminum sleeve 8, an anti-corrosion asphalt layer 9, an outer sheath 10 and an extruded semi-conductive layer 11 in sequence from the inside to the outside. The inner wall of the corrugated aluminum sleeve 8 is provided with a zinc coating or coated with a conductive anti-corrosion coating. The conductive anti-corrosion coating can use graphene-modified epoxy resin, which can effectively block the electrochemical corrosion of aluminum-water-blocking powder. Conductive silicone grease is filled between the composite water-blocking buffer layer 6 and the corrugated aluminum sleeve 8 to ensure the continuity of electrical contact. The volume resistivity of the conductive silicone grease is ≤10 3 The extruded semiconductive layer 11 has the functions of uniform electric field and providing a fault current path, which can effectively improve the insulation performance and operation safety of the high-voltage cable.

[0056] In summary, the present invention wraps a TPU material layer 5 around the insulating core of the high-voltage cable, so that a physical isolation layer is formed between the insulating core and the aluminum sleeve, blocking the electrochemical corrosion path and evenly distributing the electric field. The outside of the TPU material layer 5 is wrapped with a composite water-blocking buffer layer 6, which can quickly absorb moisture from the interface, and swell and seal the pores when it encounters water, and avoid overall moisture through the synergistic effect of absorption / hydrophobicity. The surface of the TPU material layer 5 is molded with spiral protrusions, so that the surface of the composite water-blocking buffer layer 6 has a spiral protrusion structure 7. The spiral protrusion structure 7 can effectively increase the water penetration path and enhance the water-blocking effect without increasing the thickness of the composite water-blocking buffer layer 6 too much. The inner wall of the corrugated aluminum sleeve 8 of the present invention is provided with a zinc coating or coated with a conductive anti-corrosion coating, which can effectively block the electrochemical corrosion of aluminum-water-blocking powder. Conductive silicone grease is filled between the composite water-blocking buffer layer 6 and the corrugated aluminum sleeve 8 to ensure the continuity of electrical contact. In addition, the present invention provides an extrusion process for an anti-ablation structure of a high-voltage cable, which effectively improves the interlayer bonding strength through a gradient vulcanization process. And the use of an extruder with a screw length-to-diameter ratio of 16-20 and a compression ratio of 2.0-2.5 can reduce the damage of high shear force to the physical properties of TPU to a certain extent, ensuring the stability of the processing process and good product performance.

[0057] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An anti-ablation structure for a high-voltage cable having an insulated core, characterized in that: The anti-ablation structure comprises a TPU material layer (5) arranged on the outer surface of the insulating wire core, and the TPU material layer (5) wraps the insulating wire core.

2. An anti-ablation method for a high-voltage cable having a cable insulation core, characterized in that: The anti-ablation method comprises extruding a TPU material layer (5) on the outer surface of the insulating wire core to form a physical isolation layer.

3. A high voltage cable with an anti-ablation structure, comprising an insulated core, characterized in that: The insulating wire core is wrapped with an anti-ablation structure, and the anti-ablation structure is a TPU material layer (5).

4. A high voltage cable with an anti-ablation structure according to claim 3, characterized in that: The TPU material layer (5) is wrapped with a composite water-blocking buffer layer (6), and the composite water-blocking buffer layer (6) comprises, from the inside to the outside, a water-absorbing fiber layer and a hydrophobic swelling water-blocking tape.

5. A high voltage cable with an anti-ablation structure according to claim 4, characterized in that: The surface of the TPU material layer (5) is molded with spiral protrusions with a pitch of 5 to 10 mm and a height of 1 to 2 mm. The composite water-blocking buffer layer (6) is made of glass fiber felt and acrylate water-blocking tape through double-layer winding, and the surface of the composite water-blocking buffer layer (6) has a spiral protrusion structure (7).

6. A high voltage cable with an anti-ablation structure according to claim 4, characterized in that: The outer side of the composite water-blocking buffer layer (6) is wrapped with a corrugated aluminum sleeve (8), an anti-corrosion asphalt layer (9), an outer sheath (10) and an extruded semi-conductive layer (11) in sequence from the inside to the outside, the inner wall of the corrugated aluminum sleeve (8) is provided with a zinc coating or coated with a conductive anti-corrosion coating, and conductive silicone grease is filled between the composite water-blocking buffer layer (6) and the corrugated aluminum sleeve (8), and the volume resistivity of the conductive silicone grease is ≤103Ω·cm.

7. A high voltage cable with an anti-ablation structure according to any one of claims 3 to 6, characterized in that: The insulating wire core comprises, from the inside to the outside, a cable conductor (1), a conductor shielding layer (2), an insulating layer (3) and an insulating shielding layer (4).

8. The high voltage cable with an anti-ablation structure according to claim 7, characterized in that: The cable conductor (1) is made of copper or aluminum, the conductor shielding layer (2) is made of polyethylene as a base material with conductive filler (carbon black) added, the insulating layer (3) is made of cross-linked polyethylene or ethylene-propylene rubber material, and the insulating shielding layer (4) is made of a base resin with conductive filler, cross-linking agent and antioxidant added.

9. An extrusion process for a high voltage cable anti-ablation structure, characterized in that: The anti-ablation structure of the high-voltage cable comprises a TPU material layer (5) wrapped around the outside of the insulating core, and the specific process steps are as follows: S100, raw material pretreatment, drying the TPU raw material to reduce its water content to below 0.05%; S200, melt-extrude the TPU raw material onto the outside of the insulating wire core through an extruder at a set extrusion temperature and extrusion pressure to form a TPU material layer (5); and the TPU material layer (5) is vulcanized in three stages using a gradient vulcanization process to improve the interlayer bonding strength; S300, molding spiral protrusions on the surface of the TPU material layer (5).

10. A high voltage cable with an anti-ablation structure according to claim 9, characterized in that: In the step S100, the TPU raw material is placed in an oven and heated and dried at a temperature of 85-95° C. for 11-13 hours; in the step S200, a twin-screw extruder is used as the extruder, the extrusion temperature is 180-220° C., and the extrusion pressure is 5-10 MPa; the extruder uses an extruder with a screw length-to-diameter ratio of 16-20 and a compression ratio of 2.0-2.5; during the first stage of vulcanization, the vulcanization temperature is 140-160° C., and the vulcanization time is 25-35 min; during the second stage of vulcanization, the vulcanization temperature is 175-185° C., and the vulcanization time is 15-25 min; during the third stage of vulcanization, the vulcanization temperature is 125-135° C., and the vulcanization time is 50-70 min.

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