A short network connection structure of a high-voltage transformer secondary side cable for a casting blast furnace

Abstract

A kind of high-pressure transformer secondary side cable short network connection structure for casting blast furnace, it is related to transformer secondary side cable short network connection field, including connecting plate, split connecting clamp, cooling water pipe and connecting cable, connecting plate is provided with inner connecting end and outer connecting end, cooling water flow passage is opened between the two, cooling water pipe two ends are connected on inner connecting end and transformer secondary side connecting end, split connecting clamp one side end is provided with cable binding tray, 2 split connecting clamps are connected with connecting cable and are respectively matched and are buckled on inner connecting end and secondary side connecting end, the short network connection structure adopts outer connecting cable mode and sets up high heat conduction coefficient non-metallic material cooling water pipe, avoid that connecting cable and circulating water contact occur oxidation corrosion, utilize cooling water pipe and external air heat exchange and air convection effect indirectly cooling connecting cable, can enhance production operation reliability, improve production efficiency, save production cost.

Description

Technical Field

[0001] This utility model relates to the field of short network connection of secondary side cables of transformers, and specifically to a short network connection structure of secondary side cables of a high voltage transformer used in casting blast furnaces. Background Technology

[0002] High-voltage cables must be cooled during power transmission to prevent overheating, which could lead to insulation loss, reduced insulation performance, decreased current carrying capacity, and reduced transmission capacity. Cooling methods for cables include natural cooling, forced air cooling, circulating water cooling, circulating oil cooling, and evaporative cooling. The high-voltage side voltage of high-voltage transformers used in foundry blast furnaces is typically 35kV. Given the high ambient temperature and relatively enclosed space of these transformers, as well as economic requirements in actual production, the secondary output cables are usually cooled using a direct-flow circulating water cooling method. This involves wrapping the cable with a rubber tube connected to the circulating water, placing the cable and circulating water together within the tube, and using the circulating water to directly and continuously cool the cable. The same circulating water cooling method is also commonly used in the short network connecting the transformer and the output cable. However, due to the short connection distance and space constraints, only four relatively thin braided cables can be used in parallel to connect the transformer's output terminal and the secondary output cable. Although this connection structure can better control the cable temperature during operation, the thin braided cables are generally very sensitive to corrosion under long-term continuous high-current operation. Once one cable in the short network is corroded by circulating water and dissolved oxygen, it is very easy for the cable resistance to increase and burn out. Once one cable burns out, the current load of the other cables connected in parallel will increase sharply, and they will also quickly burn out, ultimately leading to the interruption of the short network connection. In actual production, it is necessary to stop production, replace the cables, and restore the short network connection. Therefore, the existing short network connection structure of the secondary side cable of the high-voltage transformer for casting blast furnaces still has the problem of insufficient connection reliability. Frequent replacement not only affects casting production efficiency but also increases production costs. Therefore, it is necessary to study and improve this structure to solve the existing technical problems and meet the needs of high-efficiency production. Utility Model Content

[0003] The purpose of this invention is to provide a short network connection structure for the secondary side cable of a high-voltage transformer used in casting blast furnaces, thereby improving the reliability of the operation of the short network connection and providing reliable protection for industrial production.

[0004] A short network connection structure for the secondary side cable of a high-voltage transformer used in a casting blast furnace includes: a connecting plate, a split connecting clamp, a cooling water pipe, and a connecting cable. Both the connecting plate and the split connecting clamp are metal conductors. An inner connecting end and an outer connecting end are provided on the connecting plate, and a mutually penetrating cooling water flow channel is formed between the inner connecting end and the outer connecting end. The outer connecting end is used to connect to the secondary side output water-cooled cable. The connecting plate body is electrically connected to the cable bundle in the secondary side output water-cooled cable, and the cooling water flow channel on the connecting plate is also interconnected with the cooling water flow channel within the secondary side output water-cooled cable. The cooling water pipe is an insulating non-metallic material pipe with a high thermal conductivity coefficient. Its two ends are respectively connected to the inner connecting end on the connecting plate and the secondary side connecting end on the transformer, respectively, and are interconnected with the cooling water flow channel on the connecting plate and the cooling water flow channel on the secondary side connecting end on the transformer. The cooling water pipe is connected to the secondary side output water-cooled cable and the connecting plate. Within the cooling water circulation loop of the transformer, the cooling water can exchange heat with the outside air through the cooling water pipe, reducing the ambient temperature. The split connecting clamp is a semi-circular tile-shaped body, with the radius of curvature of the arc corresponding to the inner connecting end on the connecting plate and the secondary side connecting end on the transformer. A cable tying plate is provided on one end, with evenly distributed tying holes on the circumferential edge of the cable tying plate. The connecting cable is connected between the corresponding tying holes on the two split connecting clamps, so that the two split connecting clamps and the connecting cable form a connecting component. The split connecting clamps at both ends of the two connecting components are respectively combined to form a cylindrical body, and are respectively fitted and locked onto the inner connecting end on the connecting plate and the secondary side connecting end on the transformer, connecting and conducting the power line between the inner connecting end and the secondary side connecting end, keeping the connecting cable coaxial with the cooling water pipe and evenly distributed along the outer circumference of the cooling water pipe, so that the connecting cable has good air convection flow conditions.

[0005] The aforementioned short network connection structure for the secondary side cable of a high-voltage transformer used in casting blast furnaces preferably includes heat exchange fins arranged on the outer wall of the cooling water pipe to increase the heat exchange area between the cooling water pipe and the external air, thereby enhancing the heat exchange capacity between the cooling water pipe and the external space.

[0006] The aforementioned short network connection structure for the secondary side cables of a high-voltage transformer used in a casting blast furnace preferably includes a support plate made of insulating material installed on the outside of the cooling water pipe. The support plate is disc-shaped, and support grooves corresponding to the number and position of the connecting cables are formed on the edge of the disc. The connecting cables are respectively embedded in the support grooves. The support plate limits and supports the connecting cables and the cooling water pipe, maintaining a relatively stable spatial structure between them, and providing a relatively open air convection environment outside the cooling water pipe.

[0007] The aforementioned short network connection structure for the secondary side cable of a high-voltage transformer used in casting blast furnaces preferably includes two support plates on the cooling water pipe, with an external rotor motor installed between the two support plates. The stator of the external rotor motor is fixedly mounted on the cooling water pipe, and fan blades are installed on its outer casing. Driving the outer casing to rotate can accelerate the convection flow of air by the fan blades, further enhancing the heat exchange capacity between the cooling water pipe and the external air. At the same time, ventilation holes are respectively opened on the plates of the support plates to provide a smooth axial airflow channel outside the cooling water pipe.

[0008] In the aforementioned short network connection structure for the secondary side cable of a high-voltage transformer used in a casting blast furnace, the fan blades are preferably arranged in a vortex pattern to facilitate the turbulent flow of air, promote rapid mixing of air in different areas, and improve the efficiency of air convection.

[0009] The beneficial effects of this utility model are that it provides a short network connection structure for the secondary side cables of a high-voltage transformer used in casting blast furnaces. Addressing the characteristics of the environment and connection process for this structure, it employs an external connection cable and incorporates cooling water pipes made of non-metallic materials with high thermal conductivity to connect to the transformer's circulating water. This avoids direct contact between the thin connecting cable and the circulating water, reducing the tendency for oxidation and corrosion. Simultaneously, it utilizes the heat exchange between the transformer's circulating water and the external air through the cooling water pipes to lower the air temperature within the short network area. Furthermore, the air convection indirectly cools the connecting cable. Further enhancements can be made by improving the heat exchange efficiency of the cooling water pipes and accelerating the air convection speed within the short network area to further enhance the cooling effect on the connecting cable. This solves the problem of corrosion-induced burn-out failure of connecting cables in secondary side cable short networks, effectively improving the reliability of the secondary side cable short network connection, ensuring normal industrial production, increasing production efficiency, reducing production consumption, and saving production costs. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of the short network connection structure of the secondary side cable of a high-voltage transformer used in casting blast furnaces.

[0011] Figure 2 for Figure 1 Sectional view of section AA.

[0012] Figure 3 This is a structural diagram of the cooling water pipes.

[0013] Figure 4 This is a front view of the short network connection structure of the secondary side cable of a high-voltage transformer used in casting blast furnaces.

[0014] Figure 5 for Figure 4 Sectional view of section BB.

[0015] Wherein: 1 is the connecting plate, 2 is the split connecting clamp, 3 is the cooling water pipe, 4 is the connecting cable, 5 is the heat exchange fin, 6 is the support plate, 7 is the external rotor motor, 8 is the fan blade, 9 is the ventilation hole, 10 is the cable tie plate, 11 is the internal connecting end, 12 is the external connecting end, 13 is the secondary side connecting end, 14 is the sealing gasket, 15 is the fixed joint, 16 is the union joint, and 17 is the movable threaded sleeve. Detailed Implementation

[0016] Furthermore, the technical solution for which protection is sought in this utility model will be described in detail below with reference to specific embodiments and accompanying drawings.

[0017] A short network connection structure for the secondary side cables of a high-voltage transformer used in a casting blast furnace, such as... Figure 1 and Figure 5 As shown, it consists of a connecting plate 1, a split connecting clamp 2, a cooling water pipe 3, a connecting cable 4, a support plate 6, and an external rotor motor 7.

[0018] Both the connecting plate 1 and the split connecting clamp 2 are made of copper, a metallic conductor. The connecting plate 1 is a connecting component that serves to connect conductive lines and circulate cooling water. It is fixedly installed on the building structure and has an inner connecting end 11 and an outer connecting end 12 at each end. A cooling water flow channel is formed between the inner connecting end 11 and the outer connecting end 12. The outer connecting end 11 is used to connect to the cable bundle in the secondary side output water-cooled cable. The cooling water pipe 3 is made of graphene polymer composite material, which has excellent thermal conductivity and reliable electrical insulation performance. A heat exchange sleeve is fitted on the outer wall of the cooling water pipe 3. The heat exchange sleeve is also made of graphene polymer composite material. Heat exchange fins 5 are evenly arranged on the outer circumference. At the same time, two support plates 6 are symmetrically arranged in the middle. Fourteen support grooves are evenly distributed around the circumference on the edge of the disc of the support plate 6. Corresponding ventilation holes 9 are formed on the plate. Figure 3As shown, metal connectors are plastically connected to both ends of the cooling water pipe 3. To meet the process requirements of connection and assembly, one end of the metal connector is set as a fixed connector 15, the outer diameter of which is not greater than the outer diameter of the cooling water pipe 3, so that the support plate 6, the external rotor motor 7, and the heat exchange sleeve can be fitted onto the cooling water pipe 3 from the connection end of the fixed connector 15. The fixed connector 15 is provided with an external thread and a hexagonal swivel structure, which can be directly swiveled and connected to the inner connection end 11. The other end of the metal connector is set as a live connector 16, which is equipped with a movable threaded sleeve 17. The movable threaded sleeve 17 is axially limited and fitted onto the support plate 6, the external rotor motor 7, and the heat exchange sleeve. On the union joint 16, there is an axial limiting stroke L relative to the union joint 16, an internal thread is provided on the inner side, and a hexagonal swivel structure is provided on the outer side. After the fixed joint 15 is connected to the inner connecting end 11, the cooling water pipe 3 can be locked to the secondary connecting end 13 by the threaded engagement between the movable threaded sleeve 17 and the secondary connecting end 13 on the transformer, thereby connecting and connecting the cooling water flow channel of the connecting plate 1 and the transformer. Sealing gaskets 14 are respectively installed in the corresponding connection structures of the fixed joint 15 and the union joint 16 with the inner connecting end 11 and the secondary connecting end 13; the split connecting clamp 2 is a semi-circular tile-shaped body, one A cable splice tray 10 is provided on the side end. Seven splicing holes are evenly distributed on the semicircle of the cable splice tray 10. Two split connecting clips 2 can be combined to form a cylindrical body. The two sets of split connecting clips 2 are connected to each other and respectively fitted onto the inner connecting end 11 on the connecting plate 1 and the secondary side connecting end 13 on the transformer, and are bolted and locked. Between the two sets of split connecting clips 2 respectively fitted onto the inner connecting end 11 and the secondary side connecting end 13, the corresponding splicing holes are respectively spliced ​​with the connecting cable 4, connecting the power line between the inner connecting end 11 and the secondary side connecting end 13. Cable 4 is a bare stranded copper wire, braided from copper wire, with a cross-sectional area of ​​30 square millimeters. The middle portions of the 14 connecting cables 4 are respectively positioned and embedded in the support grooves opened on the edge of the support plate 6. The support plate 6 is used to spread the 14 connecting cables 4 into a spindle structure shape, which stabilizes the spatial structure between the connecting cables 4 and the cooling water pipe 3, while ensuring good air convection flow conditions in the space around the connecting cables 4 and between them. The external rotor motor 7 is installed between the two support plates 6 and fixedly mounted on the cooling water pipe 3. Four fan blades 8 are installed on the outer shell, and the fan blades 8 are evenly arranged along the outer circumference of the outer shell in a vortex pattern.

[0019] In the short network connection structure of the secondary side cable of the high-voltage transformer for casting blast furnace described in this embodiment, the connecting cable 4 is made of bare stranded copper wire with a cross-section of 30 square millimeters, and the cooling water pipe 3 is made of polymer material. This allows the network structure to maintain the structural characteristics of a soft connection, effectively reducing the transmission intensity of alternating vibration energy from the secondary side output water-cooled cable to the high-voltage transformer side, thus avoiding adverse effects on the transformer's operating state. Furthermore, separating the connecting cable 4 from the circulating cooling water fundamentally solves the problem of the connecting cable 4 being easily corroded and burned out due to long-term immersion in circulating cooling water and continuous high-current operation. Instead of the ineffective phenomenon, an indirect water cooling method is used, and air convection is utilized to cool and lower the temperature of the connecting cable 4. That is, the cooling water pipe 3 with high thermal conductivity is used as the heat exchange conductor, so that the circulating cooling water flowing through the cooling water pipe 3 exchanges heat with the air outside the pipe body, reducing the air temperature in the space outside the cooling water pipe 3. Then, the connecting cable 4 is cooled and lowered through local air convection exchange. This can effectively ensure the normal operation of the secondary side cable short network, improve the reliability of the connection and operation of the secondary side cable short network of the transformer for casting blast furnace, ensure continuous and efficient casting production, improve production efficiency, and save production costs.

Claims

1. A short network connection structure for the secondary side cable of a high-voltage transformer used in casting blast furnaces, characterized in that, include: The connection includes a connecting plate (1), a split connecting clamp (2), a cooling water pipe (3), and a connecting cable (4). Both the connecting plate (1) and the split connecting clamp (2) are metal conductors. An inner connecting end (11) and an outer connecting end (12) are provided on the connecting plate (1). A cooling water flow channel is provided between the inner connecting end (11) and the outer connecting end (12). The cooling water pipe (3) is a pipe body made of insulating non-metallic material with a high thermal conductivity coefficient. Both ends are respectively connected to the inner connecting end (11) on the connecting plate (1) and the secondary side connecting end (13) on the transformer. They are respectively connected to the cooling water flow channel on the connecting plate (1) and the cooling water flow channel on the secondary side connecting end (13) on the transformer. The split connecting clamp (2) is a semi-circular tile-shaped body. The radius of curvature of the arc is respectively connected to the inner connecting end (11) on the connecting plate (1). 1) The secondary side connection end (13) on the transformer corresponds to each other. A cable ties plate (10) is provided on one side. Uniformly distributed ties are provided at the circumferential edge of the cable ties plate (10). The connecting cable (4) is connected between the corresponding ties on the two split connecting clips (2), so that the two split connecting clips (2) and the connecting cable (4) form a connecting component. The split connecting clips (2) on both ends of the two connecting components are respectively combined to form a cylindrical body. At the same time, they are respectively fitted on the inner connecting end (11) on the connecting plate (1) and the secondary side connection end (13) on the transformer and fixed and locked. The power line between the inner connecting end (11) and the secondary side connection end (13) is connected. The connecting cable (4) is coaxially arranged with the cooling water pipe (3) and uniformly distributed along the outer circumference of the cooling water pipe (3).

2. The short network connection structure for the secondary side cable of a high-voltage transformer for a casting blast furnace as described in claim 1, characterized in that: Heat exchange fins (5) are arranged on the outer wall of the cooling water pipe (3).

3. The short network connection structure for the secondary side cable of a high-voltage transformer for a casting blast furnace as described in claim 1 or 2, characterized in that: A support plate (6) made of insulating material is installed on the outside of the cooling water pipe (3). The support plate (6) is in the shape of a disc. Support grooves corresponding to the number and position of the connecting cables (4) are opened on the edge of the disc. The connecting cables (4) are respectively embedded in the support grooves. The support plate (6) limits and supports the connecting cables (4) and the cooling water pipe (3) and their mutual relative spatial structure.

4. The short network connection structure for the secondary side cable of a high-voltage transformer for a casting blast furnace as described in claim 3, characterized in that: Two support plates (6) are provided on the cooling water pipe (3), and an external rotor motor (7) is installed between the two support plates (6). The stator of the external rotor motor (7) is fixedly mounted on the cooling water pipe (3), and a fan blade (8) is installed on the outer shell. Ventilation holes (9) are also provided on the plate of the support plate (6) respectively, so that the cooling water pipe (3) has a smooth axial airflow channel.

5. The short network connection structure for the secondary side cable of a high-voltage transformer for a casting blast furnace as described in claim 4, characterized in that: The fan blades (8) are arranged in a vortex pattern to facilitate the turbulent flow of air.

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