Transformer pipeline grounding structure using conductive paint, and method thereof

Abstract

The present invention relates to a transformer pipeline grounding structure using conductive paint, the structure comprising: coupling bolts which pass through and connect flanges connecting pipes, so as to couple the flanges; and conductive paint applied to some surface parts of the flanges through which the coupling bolts pass, so as to electrically connect the flanges. In the present invention, instead of a conventional task of connecting a grounding cable to both sides of pipes, electrically conductive paint is applied to flange surfaces or bolt fastening parts so as to perform grounding, and thus the time required for providing a grounding cable for connecting pipes can be reduced and worker safety is ensured by minimizing work at high places.

Description

Transformer pipeline grounding structure using conductive paint, and method therefor

[0001] The present invention relates to a transformer pipeline grounding structure utilizing conductive paint, and more particularly, to a transformer pipeline grounding structure utilizing conductive paint for connecting transformer pipelines with conductive paint.

[0002] Typically, transformers are connected to pipes via flanges for the circulation of transformer insulating oil. Conventionally, grounding cables are connected by welding ground lugs or other devices to the flanges or pipes, thereby electrically connecting the pipes.

[0003] This current grounding work method has problems such as requiring additional work and time in addition to the work of connecting multiple grounding cables, and the risk of accidents such as falling during work because the transformer pipes are mainly located on top of the transformer.

[0004] As a technology related to this, Republic of Korea Public Utility Model No. 20-2016-0004247 discloses a “flange assembly” configured to enable electrical connection at the fastening portion of the flange.

[0005] In these flange assemblies, cylindrical contact portions made of a conductive material for grounding are inserted into the through holes of the flanges. One end of the contact portion contacts the first through hole, and the other end of the contact portion contacts the second through hole, so that the first through hole of the first flange portion and the second through hole of the second flange are electrically conductively connected by the contact portion.

[0006] However, the conventional flange assembly solves the electrical connection of flanges by inserting a separate cylindrical flexible conductive contact part into the through holes, and since the cylindrical conductive contact part must be manufactured separately and the conductive contact part corresponding to the various specifications of the flanges must be manufactured, this acts as a factor in increasing the manufacturing cost, and there is a possibility that the metal contact part and the fastening bolt may corrode.

[0007] [Prior Art Literature]

[0008] [Patent Document]

[0009] (Patent Document 1) KR 20-2016-0004247 A1 "Flange Assembly"

[0010] Embodiments of the present invention provide a transformer pipeline grounding structure and method utilizing conductive paint, which can reduce the time required for installing a grounding cable for connecting a pipe by applying electrically conductive paint to a flange surface or a bolt joint to perform grounding instead of connecting a grounding cable to both pipes, minimize work at heights to ensure worker safety, and provide sufficient electrical conductivity while preventing corrosion of the flange joint area.

[0011] According to one aspect of the present invention, a transformer pipeline grounding structure utilizing conductive paint can be provided, including a connecting bolt penetrating through flanges to connect pipes and flanges to each other; and a conductive paint applied to a portion of the surface of the flanges through which the connecting bolt penetrates to electrically connect the flanges.

[0012] The conductive paint may be applied to at least one of the inner wall portion of a through hole provided in the flanges through which the coupling bolt passes and the nut contact surface portion of the flange corresponding to the nut coupled to the coupling bolt.

[0013] The above conductive paint can be applied to the facing flange contact surfaces of the above flanges.

[0014] The conductive paint may be arranged one or more times at intervals in an annular or radial manner.

[0015] The above conductive paint can be applied in a thickness of 0.001 mm to 0.3 mm or less.

[0016] The above conductive paint can be prepared as a conductive paint by mixing one or more of copper, graphite, silver, carbon black, and nickel powders into a paste and mixing them with the paint.

[0017] The above conductive paint can be prepared to satisfy a surface resistance of 0.25 ohm / sq or less.

[0018] According to another aspect of the present invention, a method for grounding a transformer pipeline using conductive paint can be provided, comprising: a step of determining an application area to be electrically connected by conductive paint in flanges; a pretreatment step of performing at least one of degreasing and polishing on the application area; a step of applying the conductive paint to the application area by spraying it with a spray gun; and a step of joining the application areas to the flanges using a joining bolt so that the application areas are electrically connected.

[0019] The application area in the above flange may include at least one of an inner wall portion of a through hole portion provided in the flanges for the connecting bolt to pass through and a nut contact surface portion of the flange corresponding to a nut connected to the connecting bolt.

[0020] The application area in the above flange may include the facing flange contact surfaces of the flanges.

[0021] The above application areas may be arranged one or more times at intervals in an annular or radial manner.

[0022] The above conductive paint can be applied in a thickness of 0.001 mm to 0.3 mm or less.

[0023] The above conductive paint can be prepared as a conductive paint by mixing one or more of copper, graphite, silver, carbon black, and nickel powders into a paste and mixing them with the paint.

[0024] The above conductive paint can be prepared to satisfy a surface resistance of 0.25 ohm / sq or less.

[0025] Embodiments of the present invention can provide a transformer pipeline grounding structure and method utilizing conductive paint, which can reduce the time required for installing a grounding cable for connecting a pipe by applying electrically conductive paint to a flange surface or a bolt joint to perform grounding instead of connecting a grounding cable to both pipes, minimize work at heights to ensure worker safety, and provide sufficient electrical conductivity while preventing corrosion of the flange joint area.

[0026] FIG. 1 is a cross-sectional view of a transformer pipeline grounding structure using conductive paint according to one embodiment of the present invention.

[0027] FIG. 2 is a cross-sectional view of a transformer pipeline grounding structure using conductive paint according to another embodiment of the present invention.

[0028] Fig. 3 is a side view of the flange showing the application area for the flange of Fig. 2.

[0029] Figure 4 is a flange side view showing another application area for the flange of Figure 2.

[0030] Figure 5 is a side view of the flange showing another application area for the flange of Figure 2.

[0031] Figure 6 is a diagram showing the state of use of a transformer pipeline grounding structure utilizing conductive paint according to another embodiment of the present invention.

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete, and to sufficiently convey the spirit of the present invention to those skilled in the art. Like reference numbers designate like elements throughout the specification.

[0033] FIG. 1 is a cross-sectional view of a transformer pipeline grounding structure using conductive paint according to one embodiment of the present invention.

[0034] Referring to FIG. 1, a transformer pipeline grounding structure utilizing conductive paint according to an embodiment of the present invention is configured to include a connecting bolt (20) that penetrates and connects flanges (10, 11) connecting pipes to each other, and a conductive paint (30) applied to a portion of the surface of the flanges (10, 11) through which the connecting bolt (20) penetrates so as to electrically connect the flanges (10, 11).

[0035] The flange (10) of one side pipe and the flange (11) of the other side pipe can be joined using a joining bolt (20) and nut (21) adjacent to the edge side.

[0036] Piping used in equipment such as transformers may be configured with a current-carrying ground line to ground leakage current generated in the transformer.

[0037] To configure such a grounding line, in this embodiment, conductive paint (30) is applied to the flanges (10, 11), which are connecting parts of the pipe that require grounding of leakage current, to electrically connect the flanges (10, 11).

[0038] The flanges (10, 11) are protected by having their outer surfaces coated with general paint, and are fastened by a coupling bolt (20) penetrating the flanges (10, 11) and fixed with a nut (21).

[0039] The conductive paint (30) according to the present embodiment may be applied to at least one of the inner wall portion of the through hole portion (13) provided in the flanges (10, 11) so that the coupling bolt (20) may pass through and the contact surface portion of the nut (21) of the flange corresponding to the nut (21) coupled to the coupling bolt (20).

[0040] That is, in this embodiment, conductive paint (30) is applied to the portion where the connecting bolt (20) penetrates and the connecting bolt (20) and the nut (21) come into contact and the portion where the flanges (10, 11) come into contact, thereby forming an electrical connection to the ground line.

[0041] First, the through hole (13) through which the coupling bolt (20) passes in the flanges (10, 11) is provided in a circular shape, and conductive paint (30) can be applied to the inner wall of the through hole (13) provided in each flange.

[0042] Accordingly, when the coupling bolt (20) is fastened by penetrating the flanges (10, 11), the outer peripheral surfaces on both sides of the coupling bolt (20) come into contact with the conductive paint (30) provided on the flanges (10, 11) on both sides, so that the flanges (10, 11) on both sides can be electrically connected.

[0043] The part of the coupling bolt (20) that is fitted into the through hole (13) of the flange is provided with a flat surface that is not threaded, unlike the end side where the nut (21) is coupled, so that the coupling bolt (20) can sufficiently contact the conductive paint (30) applied to the inner wall of the through hole (13).

[0044] In the case where the portion connected to the outer wall of the flange in the through hole (13) is formed in a round shape, the conductive paint (30) can be sufficiently applied to the round portion. Accordingly, the bolt head of the connecting bolt (20) and a part of the nut (21) can sufficiently come into contact with the conductive paint (30) of the round portion.

[0045] Since multiple connecting bolts (20) are arranged along the circumferential direction in the flanges (10, 11), the electrical connection between one flange (10) and the other flange (11) can be stably maintained even if some are broken.

[0046] FIG. 2 is a cross-sectional view of a transformer pipeline grounding structure using conductive paint according to another embodiment of the present invention, and FIG. 3 is a flange side view showing an application area for the flange of FIG. 2.

[0047] According to another embodiment referring to FIGS. 2 and 3, conductive paint (30) may be applied to the facing flange contact surfaces (15) of the flanges (10, 11).

[0048] One side flange (10) and the other side flange (11) can be fastened by a joining bolt (20) and a nut (21) so that the annular areas (31) on the outside of the pipe where conductive paint (30) is applied are in mutual contact.

[0049] That is, the area where the conductive paint (30) is applied in the flange contact surface (15) is an annular area (31) where the flanges (10, 11) come into contact at the outer edge of the flange contact surface (15), and the conductive paint (30) can be applied to part or all of the annular area (31).

[0050] Suitably, the conductive paint (30) may be provided in the area between the through hole portion (13) through which the coupling bolt (20) penetrates on the outside of the O-ring (12) rather than the inner area of ​​the flange contact surface portion (15) of the flange. This utilizes the fastening force of the coupling bolt (20), so that the annular area (31) in the flanges (10, 11) can be more strongly pressed by the coupling bolt (20) than the inner area.

[0051] Figure 4 is a flange side view showing another application area for the flange of Figure 2.

[0052] Referring to FIGS. 3 and 4, one or more conductive paints (30) may be arranged at intervals in an annular or radial manner.

[0053] When the conductive paint (30) is provided in an annular shape, it may be provided as one or more annular regions (31) on the outer surface of the flange contact surface portion (15). In addition, when the conductive paint (30) is provided radially, it may be provided as radial regions (32) provided at a certain angular interval along the circumferential direction on the outer surface of the flange contact surface portion (15).

[0054] Figure 5 is a side view of the flange showing another application area for the flange of Figure 2.

[0055] Referring to FIG. 5, conductive paint (30) may be provided as a square area (33) on the outer surface of the flange contact surface (15). This square area (33) may be provided to be substantially wider than the annular area (31) and the radial area (32), and may provide electrical conductivity with a more sufficient area.

[0056] Accordingly, the conductive paint (30: 31, 32) applied to the outer area of ​​the flange contact surface (15) is electrically connected by being more tightly bonded at the joint of the flanges (10, 11), and the electrical connection can be maintained even if some slight play occurs when the flanges (10, 11) vibrate.

[0057] Meanwhile, the conductive paint (30) according to the present embodiment may be applied with a thickness of 0.001 mm to 0.3 mm or less. Suitably, the conductive paint (30) may be applied with a thickness of between 40 μm and 60 μm.

[0058] In addition, the conductive paint (30) may be prepared as a conductive paint by mixing one or more of copper, graphite, silver, carbon black, and nickel powders into a paste and mixing them with the paint. Conductive powders such as copper, graphite, silver, carbon black, and nickel are conductive materials that are advantageous for mixing with paint and have excellent electrical properties, and may be appropriately mixed into the paint material or used alone. At this time, an antioxidant that prevents oxidation of the conductive material may be mixed into the conductive paint (30).

[0059] This conductive paint (30) can be prepared to satisfy a surface resistance of 0.25 ohm / sq or less. This provides a resistance suitable for grounding leakage current in the oil circulation pipe of the transformer, and can vary depending on the application target of the flanges (10, 11) connected by the conductive paint (30).

[0060] Conductive paint (30) is composed of a mixture of a pasted metal conductor and a liquid resin paint, and the powder ratio of the metal conductor to the liquid resin paint can be adjusted so as to satisfy a surface resistance of 0.25 ohm / sq or less.

[0061] Hereinafter, a transformer pipeline grounding method using conductive paint according to one embodiment of the present invention is provided.

[0062] Referring to FIGS. 1 to 5, a method for grounding a transformer pipeline using conductive paint according to an embodiment of the present invention may include a step of determining an application area to be electrically connected by conductive paint (30) in flanges (10, 11), a pretreatment step of performing at least one of degreasing and polishing on the application area, a step of applying conductive paint (30) by spraying it on the application area with a spray gun, and a step of joining the application area to the flanges (10, 11) using a joining bolt (20) so that the application area is electrically connected.

[0063] The application area in the flange may include at least one of the inner wall portion of the through hole portion (13) provided in the flanges (10, 11) so that the coupling bolt (20) passes through and the contact surface portion of the nut (21) of the flange corresponding to the nut (21) coupled to the coupling bolt (20).

[0064] In this way, the application area of ​​the conductive paint (30) can be determined as the through hole (13) or the flange contact surface (15) provided for the connecting bolt (20) to pass through in the flanges (10, 11) as described above. Of course, the conductive paint (30) can also be applied to both the through hole (13) and the flange contact surface (15).

[0065] In addition, referring to FIGS. 3 to 5, the application area in the flange may be included in the facing flange contact surface portion (15) of the flanges (10, 11). At this time, one or more application areas may be arranged at annular or radial intervals. In addition, the application area may be provided in a square shape. Since this application area has already been described in the flange contact surface portion (15) described above, a redundant description will be omitted.

[0066] Once the application area of ​​the conductive paint (30) is determined on the flanges (10, 11), the application area can be smoothed or oil removed. This makes the contact surface smooth after the conductive paint (30) is applied, and can increase the adhesion between the conductive paint (30) and the application area. In practice, the through hole portion (13) among the application areas of the conductive paint (30) is usually subjected to the smoothing symbol x, but can be smoothed by applying the smoothing symbol y or higher, and the flange contact surface portion (15) can also be smoothed by applying the smoothing symbol y or higher.

[0067] Meanwhile, the conductive paint (30) may be applied with a thickness of 0.001 mm to 0.3 mm or less. In addition, the conductive paint (30) may be prepared as a conductive paint in which one or more of copper, graphite, silver, carbon black, and nickel powders are mixed into a paste and then mixed with the paint. The conductive paint (30) may be prepared to satisfy a surface resistance of 0.25 ohm / sq or less.

[0068] The conductive paint (30) and its thickness, material, and resistance value can be applied in the same manner as previously described.

[0069] Figure 6 is a diagram showing the state of use of a transformer pipeline grounding structure utilizing conductive paint according to one embodiment of the present invention.

[0070] Referring to FIG. 6, the transformer pipeline grounding structure and method using conductive paint according to embodiments of the present invention can be applied to a pipe for circulating insulating oil of a transformer.

[0071] Assuming the application target of the embodiments of the present invention, in the pipe for circulating the transformer insulating oil, the connection between the pipes is made through flanges (10, 11), and the grounding work method requires additional work and time in addition to the work of connecting a number of grounding cables, and since the location of the transformer pipe is mainly located at the top of the transformer, problems such as the risk of falling accidents during work may arise.

[0072] By applying a transformer pipeline grounding structure and method utilizing conductive paint (30) according to embodiments of the present invention to the insulating oil pipe of such a transformer, the grounding current can be made to flow naturally by applying electrically conductive paint (30) to the flange surface or bolt joint.

[0073] Meanwhile, in the above-described embodiments, it has been described that conductive paint (30) is applied between the flanges on both sides of the pipe connection through which insulating oil passes and the flanges (10, 11), but this is not limited thereto, and the application area of ​​the conductive paint (30) may further include a bolt fastening portion, a gasket, and an insulating washer (EGP Washer).

[0074] While the present invention has been described above with reference to one embodiment, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention as defined in the claims below. Therefore, any modified implementation that fundamentally includes the elements of the claims should be considered within the technical scope of the present invention.

[0075] [Explanation of symbols]

[0076] 10, 11: Flanges

[0077] 13: Penetrating hole

[0078] 15: Flange contact surface

[0079] 20: Combination bolt

[0080] 21: Nuts

[0081] 30: Conductive paint

[0082] 31: Circular area

[0083] 32: Radiation area

[0084] 33: Square area

Claims

1. A connecting bolt that penetrates and connects the flanges connecting the pipes to each other; and A transformer pipeline grounding structure utilizing conductive paint, comprising conductive paint applied to a portion of the surface of the flanges through which the connecting bolt penetrates to electrically connect the flanges.

2. In paragraph 1, A transformer pipeline grounding structure utilizing conductive paint, wherein the conductive paint is applied to at least one of the inner wall portion of the through hole provided in the flanges through which the coupling bolt passes and the nut contact surface portion of the flange corresponding to the nut coupled to the coupling bolt.

3. In paragraph 1, A transformer pipeline grounding structure utilizing conductive paint, wherein the conductive paint is applied to the facing flange contact surfaces of the flanges.

4. In paragraph 3, The above conductive paint is a transformer pipeline grounding structure utilizing conductive paint, one or more of which are spaced annularly or radially.

5. In paragraph 1, The above conductive paint is applied with a thickness of 0.001 mm to 0.3 mm or less, and is a transformer pipeline grounding structure utilizing conductive paint.

6. In paragraph 1, The above conductive paint is a transformer pipeline grounding structure utilizing conductive paint, wherein the conductive paint is prepared by mixing one or more of copper, graphite, silver, carbon black, and nickel powders into a paste and mixing them with the paint.

7. In paragraph 6, The above conductive paint is a transformer pipeline grounding structure utilizing conductive paint, which is provided so as to satisfy a surface resistance of 0.25 ohm / sq or less.

8. A step of determining the application area to be electrically connected by conductive paint on the flanges; A pretreatment step of performing at least one of degreasing and polishing on the above application area; A step of applying the conductive paint by spraying it onto the application area using a spray gun; and A method for grounding a transformer pipeline using conductive paint, comprising the step of using a joining bolt to electrically connect the application areas of the above flanges.

9. In paragraph 8, A method for grounding a transformer pipeline using conductive paint, wherein the application area in the flange includes at least one of an inner wall portion of a through hole portion provided in the flanges for the coupling bolt to penetrate through and a nut contact surface portion of the flange corresponding to a nut coupled to the coupling bolt.

10. In paragraph 8, A method for grounding a transformer pipeline using conductive paint, wherein the application area of ​​the above flange includes the facing flange contact surfaces of the above flanges.

11. In Article 10, The above application area is a method for grounding a transformer pipeline using conductive paint, wherein one or more of the application areas are spaced out in an annular or radial manner.

12. In paragraph 8, A method for grounding a transformer pipeline using conductive paint, wherein the conductive paint is applied with a thickness of 0.001 mm to 0.3 mm or less.

13. In paragraph 8, The above conductive paint is a method for grounding a transformer pipeline using conductive paint, wherein the conductive paint is prepared by mixing one or more of copper, graphite, silver, carbon black, and nickel powders into a paste and mixing them with paint.

14. In paragraph 8, The above conductive paint is a method for grounding a transformer pipeline using conductive paint, wherein the conductive paint is prepared to satisfy a surface resistance of 0.25 ohm / sq or less.

Images