Liquid nitrogen cooling high-power medium-voltage cable

Abstract

The utility model discloses a liquid nitrogen cooling high-power medium-voltage cable, which relates to the cable field, and comprises a power transmission core, a cooling pipe and a heat conduction filling strip, the power transmission core, the cooling pipe and the heat conduction filling strip are twisted to form a cable core, a soaking wrapping layer is wrapped outside the cable core, a polypropylene wrapping layer is wrapped outside the soaking wrapping layer, and the polypropylene wrapping layer is wrapped outside the polypropylene wrapping layer. And a high-density polyethylene sheath is wrapped outside the polypropylene wrapping layer. The conductors in the cable are made of oxygen-free copper materials, the outer diameter is smaller under the condition of the same conductor cross section, the structure is compact, the conductivity is excellent, and the transmission calorific value is small; circulating cooling of liquid nitrogen is achieved by arranging the liquid nitrogen pipe, heat in high-power operation of the cable can be rapidly taken away, and the current-carrying capacity of the cable is greatly improved. The cooling pipe is formed by interlocking and armoring a liquid nitrogen pipe and nickel steel, the strength is high, and the reliability of liquid nitrogen circulation is achieved; the heat conduction filling strips are arranged in the gaps between the cooling pipes and the power transmission cores, and the soaking wrapping layer is wrapped outside the cable core, so that the heat in the cable can be effectively homogenized, and the cooling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of cables, in particular to a liquid nitrogen cooled high-power medium-voltage cable. Background Art

[0002] With the rapid development of the economy and society, the number of high-load power-consuming projects, such as super-tall landmark buildings, large industrial parks, petrochemical plants, and steel mills, continues to increase. Given the limitations of voltage levels and conductor cross-sections, achieving high-power transmission of electrical energy requires increasing the current carrying capacity of cables. Fluctuations in raw material prices directly impact the market for copper conductor cables. Effectively improving the heat dissipation capacity of the cable itself can conserve conductor material and achieve high-power transmission of electrical energy. Current approaches to heat dissipation in cable installations generally involve increasing the installation space or adding active ventilation, but these are often less than ideal in the summer when ambient temperatures rise. Utility Model Content

[0003] The purpose of the utility model is to provide a liquid nitrogen cooled high-power medium voltage cable in order to solve the above problems.

[0004] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0005] A liquid nitrogen cooled high-power medium-voltage cable comprises a power transmission core, a cooling tube and a thermally conductive filling strip, wherein the power transmission core, the cooling tube and the thermally conductive filling strip are twisted together to form a cable core, the cable core is wrapped with a heat-equalizing wrapping layer on the outside, the heat-equalizing wrapping layer is wrapped with a polypropylene wrapping layer on the outside, and the polypropylene wrapping layer is wrapped with a high-density polyethylene sheath on the outside, the power transmission core comprises a conductor, the conductor is made of oxygen-free copper, and the conductor is twisted by heterosexual single wires, the conductor is wrapped with a semi-conductive inner shielding layer on the outside, the semi-conductive inner shielding layer is wrapped with an XLPE insulation layer on the outside, the XLPE insulation layer is wrapped with a semi-conductive outer shielding layer on the outside, and the semi-conductive outer shielding layer is wrapped with a copper tape shielding layer on the outside, the cooling tube comprises a liquid nitrogen tube, the liquid nitrogen tube is wrapped with a nickel steel interlocking armor layer on the outside, and the thermally conductive filling strip is filled in the gap between the power transmission core, the cooling tube and the heat-equalizing wrapping layer.

[0006] Preferably, the liquid nitrogen tube is made of medical-grade liquid nitrogen FPP special material.

[0007] Preferably, the ratio of the outer diameter of the cooling tube to the outer diameter of the power transmission core is 0.48:1.

[0008] Preferably, the material of the nickel steel interlocking armor layer is 12% Ni steel.

[0009] Preferably, the thermally conductive filling strip and the heat-equalizing wrapping layer are both made of flexible thermally conductive silicone material.

[0010] The beneficial effects are:

[0011] 1. The conductor in this cable is made of oxygen-free copper. With the same conductor cross-section, the outer diameter is smaller, the structure is compact, the conductivity is excellent, and the heat generated during transmission is small.

[0012] 2. By setting up a liquid nitrogen pipe to achieve liquid nitrogen circulation cooling, the heat generated by the cable during high-power operation can be quickly removed, greatly improving the cable's current carrying capacity.

[0013] 3. The cooling pipe is composed of liquid nitrogen pipe and nickel steel interlocking armor, which has high strength and realizes the reliability of liquid nitrogen circulation.

[0014] 4. There is a thermal conductive filling strip in the gap between the cooling tube and the power transmission core, and the cable core is wrapped with a heat-equalizing layer, which can effectively equalize the heat inside the cable and improve the cooling efficiency.

[0015] Additional technical features and advantages of the present invention will be more clearly explained in the following description, or can be understood through specific practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 It is a schematic diagram of a liquid nitrogen cooled high-power medium-voltage cable described in the present invention.

[0018] The accompanying drawings are marked as follows: 1. Power transmission core; 2. Conductor; 3. Semi-conductive inner shielding layer; 4. XLPE insulation layer; 5. Semi-conductive outer shielding layer; 6. Copper tape shielding layer; 7. Liquid nitrogen pipe; 8. Nickel steel interlocking armor layer; 9. Cooling pipe; 10. Thermal conductive filling strip; 11. Heat-equalizing wrapping layer; 12. Polypropylene wrapping layer; 13. High-density polyethylene sheath. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely 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.

[0020] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] like Figure 1 As shown, a liquid nitrogen cooled high-power medium voltage cable includes a power transmission core 1, a cooling tube 9 and a heat conductive filling strip 10. The power transmission core 1 and the cooling tube 9 are both provided with three, and the three power transmission cores 1 are in contact with each other to form a triangular distribution. The cooling tubes 9 are evenly distributed on the outside of the power transmission core 1. The power transmission core 1, the cooling tube 9 and the heat conductive filling strip 10 are twisted to form a cable core. The power transmission core 1 includes a conductor 2. The conductor 2 is made of oxygen-free copper, has excellent electrical conductivity, and generates less heat when transmitted. Specifically, the conductor 2 uses two types of heterosexual single-wire copper conductors. In the same The outer diameter is smaller under the cross-section, the conductor 2 is made of heterosexual single wires, the outside of the conductor 2 is wrapped with a semi-conductive inner shielding layer 3, the outside of the semi-conductive inner shielding layer 3 is wrapped with an XLPE insulation layer 4, the outside of the XLPE insulation layer 4 is wrapped with a semi-conductive outer shielding layer 5, and the outside of the semi-conductive outer shielding layer 5 is wrapped with a copper tape shielding layer 6. The semi-conductive inner shielding layer 3, XLPE insulation layer 4 and semi-conductive outer shielding layer 5 are co-extruded on the outside of the conductor 2, so that the power transmission core 1 has higher insulation performance and can meet the power system transmission of 35kV and below voltage levels.

[0023] The cooling pipe 9 includes a liquid nitrogen pipe 7, which is wrapped with a nickel-steel interlocking armor layer 8 on the outside. The liquid nitrogen pipe 7 is made of medical-grade liquid nitrogen FPP special material. Specifically, the liquid nitrogen pipe 7 is extruded with ultra-low temperature resistant FPP medical-grade special polypropylene, which has high strength and can withstand low temperatures of -196°C. It has the performance of storing and transmitting liquid nitrogen. The nickel-steel interlocking armor layer 8 is made of 12% Ni steel and can be used in low-temperature conditions of 4 to 77K, thereby protecting the liquid nitrogen pipe 7 without affecting the cooling effect. The ratio of the outer diameter of the cooling pipe 9 to the outer diameter of the power transmission core 1 is 0.48:1, ensuring that the cooling pipe 9 and the power transmission core 1 are in contact and the cable is round.

[0024] The cable core is wrapped with a heat-equalizing wrapping layer 11 on the outside, and the thermally conductive filling strips 10 are filled in the gaps between the power transmission core 1, the cooling tube 9 and the heat-equalizing wrapping layer 11. The thermally conductive filling strips 10 and the heat-equalizing wrapping layer 11 are both made of flexible thermally conductive silicone material, which has good thermal conductivity and a thermal conductivity coefficient of up to 5.0W / mK. The cooling tube 9 and the heat-equalizing wrapping layer 11 serve as contact media between the cooling tube 9 and the power transmission core 1, and can achieve good heat conduction and temperature equalization effects, thereby increasing the internal cooling level of the cable.

[0025] The heat-equalizing wrapping layer 11 is wrapped with a polypropylene wrapping layer 12 on the outside, which can protect the heat-equalizing wrapping layer 11 from damage. The polypropylene wrapping layer 12 is wrapped with a high-density polyethylene sheath 13 on the outside, which has a low-temperature impact brittle temperature of -76°C and strong stress resistance, and the sheath will not crack due to the internal low temperature.

[0026] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements shall fall within the scope of the present invention as claimed.

Claims

1. A liquid nitrogen cooled high power medium voltage cable, characterized by: The invention comprises a power transmission core (1), a cooling tube (9) and a heat-conducting filling strip (10), wherein the power transmission core (1), the cooling tube (9) and the heat-conducting filling strip (10) are twisted together to form a cable core, the cable core is wrapped with a heat-equalizing wrapping layer (11) on the outside, the heat-equalizing wrapping layer (11) is wrapped with a polypropylene wrapping layer (12) on the outside, and the polypropylene wrapping layer (12) is wrapped with a high-density polyethylene sheath (13) on the outside, the power transmission core (1) comprises a conductor (2), the conductor (2) is made of oxygen-free copper, the conductor (2) is twisted with heterosexual single wires, and the The conductor (2) is wrapped with a semi-conductive inner shielding layer (3) on the outside, the semi-conductive inner shielding layer (3) is wrapped with an XLPE insulation layer (4) on the outside, the XLPE insulation layer (4) is wrapped with a semi-conductive outer shielding layer (5) on the outside, the semi-conductive outer shielding layer (5) is wrapped with a copper tape shielding layer (6) on the outside, the cooling pipe (9) includes a liquid nitrogen pipe (7), the liquid nitrogen pipe (7) is wrapped with a nickel steel interlocking armor layer (8) on the outside, and the thermal conductive filling strip (10) is filled in the gap between the power transmission core (1), the cooling pipe (9) and the heat-equalizing wrapping layer (11).

2. The liquid nitrogen cooled high-power medium voltage cable according to claim 1, characterized in that: The liquid nitrogen tube (7) is made of medical-grade liquid nitrogen FPP special material.

3. The liquid nitrogen cooled high-power medium voltage cable according to claim 1, characterized in that: The ratio of the outer diameter of the cooling tube (9) to the outer diameter of the power transmission core (1) is 0.48:

1.

4. The liquid nitrogen cooled high-power medium voltage cable according to claim 1, characterized in that: The nickel steel interlocking armor layer (8) is made of 12% Ni steel.

5. The liquid nitrogen cooled high-power medium voltage cable according to claim 1, characterized in that: The thermally conductive filling strip (10) and the heat-equalizing wrapping layer (11) are both made of flexible thermally conductive silicone material.

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