JP5736001B2 - Repair method of return pipe and intermediate connection part of return pipe - Google Patents

Description

  The present invention relates to a method for repairing a return pipe constituting a refrigerant flow path of an indirect cooling system of an underground power transmission network and an intermediate connection portion of the return pipe.

In recent years, particularly in urban areas and urban areas, power cables have been laid on shelves and troughs in the cave provided in the ground, and underground power transmission networks that use this to transmit power have been developed. In underground power transmission networks, power cables have been increased in capacity and voltage, and the amount of heat generated by power cables has increased accordingly. If the temperature rises due to heat generation of the power cable, the insulation performance of the power cable may be impaired, and the working environment in the cave deteriorates, so the power cable is cooled in the cave (including in the trough). A cooling system is installed.
Conventionally, in this type of cooling system, air (in the trough) is cooled by flowing a refrigerant (for example, water) through an outward pipe laid along the power cable, and the power cable is indirectly connected. An indirect cooling system for cooling is known (for example, Patent Documents 1 to 4).

FIG. 1 is a schematic diagram showing a configuration in a cave of an underground power transmission network.
As shown in FIG. 1, shelves 12 and troughs 13 are arranged in multiple stages in the cave 11, and various cables 14 to 16 are laid on them. In the example shown in FIG. 1, an ultrahigh voltage power cable 14 is laid in the trough 13, and an outgoing pipe 21 for cable cooling is laid along the cable 14.
When the low-temperature (for example, 10 ° C.) refrigerant sent from the cooling device (not shown) flows through the forward pipe 21, the inside of the trough 13 is cooled and the power cable 14 is indirectly cooled. Further, the refrigerant that has absorbed heat and has reached a high temperature (for example, 30 to 40 ° C.) is recovered by a cooling device (not shown) through a return pipe 22 laid in the sinus 11.

  Generally, a stainless steel pipe having high heat transfer performance is used for the forward pipe 21. On the other hand, since high heat transfer performance is not required for the return pipe 22 and it is not necessary to use a high-cost stainless steel pipe, for example, a rubber pipe (hereinafter, rubber pipe) is used. Usually, the rubber pipe used for the return pipe 22 is a made-to-order product.

The return pipe 22 is provided with an intermediate connection portion every several tens to several hundreds of meters, and the rubber tube can be exchanged in units of sections sandwiched between the intermediate connection portions.
Specifically, as shown in FIG. 2, in the intermediate connection portion 100, two rubbers are connected via pipe-shaped intermediate connection fittings 110 having pipe-line attachment portions 111 and 112 for attaching pipe lines to both ends. The tubes 120A and 120B are connected. In the example illustrated in FIG. 2, the intermediate connection fitting 110 is partitioned into pipe attachment portions 111 and 112 with a central portion 115 in the center in the longitudinal direction interposed therebetween. A stainless hose band 130 is disposed on the outer periphery of the rubber tube 120 at a position corresponding to the ring-shaped recess 113 formed on the outer peripheral surfaces of the pipe attachment portions 111 and 112. By tightening the hose band 130 with a predetermined torque, the hose band 130 bites into the rubber pipe 120, and the rubber pipes 120A and 120B and the intermediate connection fitting 110 are connected and fixed in a watertight manner.

Japanese Patent Publication No. 5-72163 Japanese Examined Patent Publication No. 63-46645 JP-A-9-89181 JP 2002-354620 A

  By the way, the rubber pipe used for the return pipe may be cracked due to damage such as aging and mechanical wear. And if water leaks from a crack and the crack progresses further and the amount of water leaks increases, a serious failure alarm will occur and the power transmission equipment will not function. Therefore, when the rubber tube is damaged, it is replaced with a new rubber tube.

However, regular rubber pipes that are applied as return pipes are made-to-order products, so delivery times are slow, and replacement may take several months. Moreover, a regular rubber tube is hard to deform | transform and lacks in flexibility. For this reason, it is difficult to manage and requires large-scale repair work, and further, adjustment of the work schedule is required.
As described above, even if the rubber tube is found to be damaged, it is difficult to immediately replace the portion with a new rubber tube, and the rubber tube is left for a while. Such a situation is not so dangerous as to cause a power transmission accident in the near future, but it is desirable to respond as soon as possible from the viewpoint of safety and reliability.

  An object of the present invention is to provide a repair method for a return pipe that can quickly cope with a case where damage is found in a part of the return pipe, and can improve the safety and reliability of the underground power transmission network, and It is to provide an intermediate connection for the return pipe.

The return pipe repair method according to the present invention includes an intermediate connection part in which two rubber pipes are connected via a pipe-like intermediate connection member having a pipe attachment part for attaching a pipe line to each of both ends. A method of repairing a return pipe constituting a refrigerant flow path of a cooling system of an underground power transmission network,
A first step of removing a damaged rubber tube from the intermediate connecting member to which the damaged rubber tube is connected;
A second step of applying a sealing material to the outer peripheral surface of the repair pipe attachment portion on the side where the damaged rubber pipe of the intermediate connecting member is removed;
It has flexibility and water impermeability, can be stored in a flat state, and forms a notch of a predetermined length at the end of a soft hose having a water impermeable layer made of synthetic resin and a reinforcing layer made of synthetic fiber , A third step of extrapolating the soft hose until the end of the soft hose exceeds the central end of the repair conduit mounting portion on the side where the sealing material of the intermediate connecting member is applied;
A fourth step of attaching a first fastening bracket to the outer peripheral surface of the soft hose and fastening the repair hose with a predetermined torque with respect to the repair pipe attachment part;
A fifth step of folding the soft hose outward in the vicinity of the center side end of the repair conduit attaching portion;
And a sixth step of attaching a second fastening bracket to the outer peripheral surface of the folded portion of the soft hose and tightening the repair pipe attachment portion with a predetermined torque.

The intermediate connection portion of the return pipe according to the present invention is an intermediate connection portion of the return pipe constituting the refrigerant flow path of the cooling system of the underground power transmission network,
A pipe-like intermediate connecting member having a pipe attachment portion for attaching the pipe to each of both ends;
A flexible hose that is attached to at least one of the conduit attachment portions and is folded outward through a notch of a predetermined length formed in an end portion and has flexibility and water impermeability and can be stored in a flat state. When,
A first fastening member disposed on an outer peripheral surface of the unfolded portion of the soft hose, and fastened to the pipe attachment portion;
A second fastening member disposed on the outer peripheral surface of the folded portion of the soft hose, and fastened to the pipe line attachment portion;
A seal portion interposed between the pipe line attachment portion and the soft hose.

  According to the present invention, by using a soft hose instead of a regular rubber tube, if damage is found in a part of the return pipe, it can be repaired quickly, so the safety of the underground power transmission network, Reliability is greatly improved.

It is the schematic which shows the structure in the tunnel of an underground power transmission network. It is a figure which shows the intermediate connection part of a return pipe. It is a figure which shows an example of the soft hose applied in embodiment. It is a figure which shows the notch | incision of a soft hose. It is a figure which shows the repair process of the return pipe which concerns on embodiment. It is a figure which shows the repair process of the return pipe which concerns on embodiment. It is a figure which shows the repair process of the return pipe which concerns on embodiment. It is a figure which shows the intermediate connection part of the return pipe after the repair which concerns on embodiment. It is a figure which shows another example of the intermediate connection part of the return pipe after the repair which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As described in the background art, a cooling system for cooling the power cable is installed in the cave where the underground power transmission network is laid. As shown in FIG. 1, the cooling system includes an outward pipe 21 and a return pipe 22 that recirculate the refrigerant. The low-temperature (for example, 10 ° C.) refrigerant sent from the cooling device (not shown) flows through the forward pipe 21, whereby the power cable 14 is indirectly cooled. Moreover, the refrigerant | coolant which absorbed heat and became high temperature (for example, 30-40 degreeC) passes through the return pipe 22, and is collect | recovered by the cooling device (not shown). In the return pipe 22 constituting the refrigerant flow path of the cooling system, an intermediate connection portion 100 is provided every several tens to several hundreds m (for example, 60 m) (see FIG. 2).

  In the present embodiment, a repair method will be described in the case where one rubber tube 120A connected by the intermediate connecting portion 100 shown in FIG. 2 is damaged. That is, in this embodiment, the intermediate connection part (100) in which two rubber pipes (120A, 120B) are connected via the intermediate connection member (intermediate connection fitting 110) is provided, and the cooling system for the underground power transmission network is provided. A method for repairing the return pipe 22 constituting the refrigerant flow path will be described.

The intermediate connection fitting 110 is, for example, a stainless steel pipe-like member, and has pipe attachment portions 111 and 112 for attaching pipes to both ends. Here, as shown in FIG. 2 and the like, the intermediate connection fitting 110 is divided into three parts, that is, the pipe attachment portions 111 and 112 and the central portion 115, but one end with the center in the longitudinal direction of the intermediate connection fitting 110 as a boundary. The pipe attachment part 111 may be the side, and the pipe attachment part 112 may be the other end.
A plurality of ring-shaped recesses 113 are formed on the outer peripheral surfaces of the respective pipe attachment portions 111 and 112. Hose bands 130 and 140 described later are arranged at positions corresponding to the ring-shaped recess 113.

  Moreover, the part adjacent to the recessed part 113 becomes the taper part 114 which diameter-expands toward the longitudinal direction center side. Here, the outer diameter of the central portion 115 of the intermediate connection fitting 110 is the same as the outer diameter of the large-diameter side of the taper portion 114 on the most central side of each of the pipe attachment portions 111 and 112. Since the pipe connected to the intermediate connection fitting 110 is expanded in diameter by the intermediate connection fitting 110 and further partially enlarged by the tapered portion 114, the adhesion to the intermediate connection fitting 110 is improved.

  In FIG. 2, when damage is found in the rubber tube 120 </ b> A, the rubber tube 120 </ b> A is removed from the intermediate connection fitting 110 (the right side pipe attachment portion 111) and replaced with a new rubber tube. However, since the new rubber tube is a made-to-order product and is ordered after the damage of the rubber tube 120A is found, it cannot be replaced immediately. In the present embodiment, as an emergency measure, the damaged rubber tube 120A is replaced with a soft hose and replaced with a new rubber tube.

  The soft hose applied in the present embodiment is a long cylindrical body having flexibility and water impermeability, and can be folded and stored in a flat state that is normally flattened. The soft hose has pressure resistance (for example, working pressure: 0.7 MPa or more) that can withstand the pressure (for example, 0.3 to 0.5 MPa) when the refrigerant flows through the return pipe 22. As the soft hose, for example, a commercially available cloth knitted hose (trade name: heavy duty sunny hose) made of polyester as a fiber material and coated with soft vinyl chloride (PVC) can be used.

FIG. 3 is a diagram illustrating an example of a soft hose.
The soft hose 200 shown in FIG. 3 is a heavy duty sunny hose (trade name) having an inner diameter of 155 mm (nominal diameter of 150 mm), a wall thickness of 2.95 mm, and a maximum operating pressure of 0.7 MPa. The soft hose 200 includes an innermost layer 201, a first reinforcing layer 202 formed on the outer periphery of the innermost layer 201, a second reinforcing layer 203 formed on the outer periphery of the first reinforcing layer 202, and an outer periphery of the second reinforcing layer 203. An outermost layer 204 is formed. The innermost layer 201 and the outermost layer 204 are impermeable layers made of a synthetic resin such as soft vinyl chloride. The 1st reinforcement layer 202 and the 2nd reinforcement layer 203 are reinforcement layers comprised by synthetic fibers, such as a polyester fiber. The soft hose 200 is processed into a four-layer structure by, for example, extrusion molding.

  While the delivery date of the regular rubber tube used for the return pipe is 2-3 weeks, the commercially available soft hose 200 can be obtained in about two days, so that the rubber tube 120A is damaged. When discovered, we can respond immediately. In addition, the weight is lighter than that of a regular rubber tube, and since it is stored in a flat state and the handling property is remarkably easy, the repair work is easy and easy to work.

4-8 is a figure which shows the repair process of the return pipe which concerns on embodiment. In the following, the side where the rubber pipe is replaced among the pipe line attaching parts 111 and 112 of the intermediate connection fitting 110 is referred to as a repair pipe line attaching part.
When damage is found in the rubber tube 120A in the intermediate connection portion 100 shown in FIG. 2, first, the soft hose 200 is drawn into the sinus and transported to the repair site in a folded state. And the notch S of the predetermined length extended in a longitudinal direction previously is formed in the edge part of the soft hose 200 (refer FIG. 4). For example, when forming two cuts, as shown in FIG. 4, the cuts S are formed on both sides in the width direction of the soft hose 200 crushed in a flat state. Thereby, the operation | work which extrapolates the soft hose 200 to the intermediate | middle connection metal fitting 110 becomes easy. Note that the soft hose 200 may be drawn into the sinus after the cut is formed in the soft hose 200.

  The length of the notch S formed in the soft hose 200 is a length corresponding to the folded portion (here, the length equivalent to the repair pipeline attaching portion 111, that is, approximately half the length of the intermediate connecting fitting 110). (For example, in FIG. 4, the length of the cut S is 150 mm). Thereby, the cut S is formed even in the portion that is not folded back, and the adhesion between the soft hose 200 and the intermediate connection fitting 110 can be avoided, and the soft hose 200 is extrapolated to the intermediate connection fitting 110. Is extremely easy.

  Further, from the viewpoint of workability and friction strength, it is preferable to form a plurality of cuts S so that the circumferential direction of the soft hose 200 is divided into 2 to 4 parts. FIG. 4 shows an example in which two cuts S are formed so that the circumferential direction of the soft hose 200 is divided into two. When the cut S is at one place, the workability when the soft hose 200 is extrapolated to the intermediate connection fitting 110 and the workability when the soft hose 200 is folded back are deteriorated. Therefore, the cut S is preferably set at two or more places. Further, when the cuts S are 5 or more, the workability when attaching the soft hose 200 is improved, but the work for forming the cuts S is increased, and the contact area after the folding is reduced, so that the friction strength is weakened. Since the possibility of the soft hose 200 falling off from the intermediate connection fitting 110 when the refrigerant is flowed increases, it is preferable that the cuts S be four or less.

  Then, as shown in FIG. 5, the hose band 130 that has fixed the rubber tube 120 </ b> A is removed, and the damaged rubber tube 120 </ b> A is removed from the intermediate connection fitting 110 (the right-side pipe attachment portion 111) (first step). .

Next, as shown in FIG. 6, a sealing material is applied to the outer peripheral surface of the repair pipe attachment portion 111 to form the seal portion 150 (second step). The sealing material is preferably excellent in water tightness, adhesiveness, followability and durability, and for example, silicone rubber can be applied. Silicone rubber as a sealing material is in a paste form before application, and after being applied to the repair conduit attaching portion 111, it is cured to become a rubber elastic body.
The application thickness and application state of the sealing material are not particularly limited, but are preferably uniform and uniform. In addition, the sealing material may be applied only to the recesses 113A and 113B of the repair pipeline attaching portion 111.

Next, as shown in FIG. 7, the soft hose 200 is intermediately connected from one end side (the repair conduit attachment portion 111 side) until the end portion of the soft hose 200 exceeds the central end portion of the repair conduit attachment portion 111. Extrapolated to the metal fitting 110 (third step). That is, the soft hose 200 is in a state where it can be folded back near the center side end of the repair pipe attachment part 111. Here, the boundary portion with the central portion 115 of the intermediate connection fitting 110 becomes the central-side end portion of the repair pipeline attaching portion 111.
In addition, although illustration is abbreviate | omitted in FIG. 7, the seal | sticker part 150 interposes between the soft hose 200 and the intermediate | middle connection metal fitting 110 (repair pipe attachment part 111). The same applies to FIG. Further, in FIGS. 2 and 5 to 8, a seal portion is similarly interposed between the rubber tube 120 </ b> B and the intermediate connection fitting 110 (the pipe line attachment portion 112).

  Specifically, when the soft hose 200 is folded back in the vicinity of the center side end of the repair pipe attachment portion 111, the soft hose 200 is removed so that at least the recess 113A on the center side in the longitudinal direction is covered with the soft hose 200. Insert. In the example shown in FIG. 7, since the soft hose 200 is extrapolated so as to cover the entire intermediate connection fitting 110, the repair conduit including the recess 113 </ b> A at the folded portion of the soft hose 200 when the soft hose 200 is folded. The entire attachment portion 111 is covered.

  Next, as shown in FIG. 7, the hose band 130 is attached to the outer peripheral surface of the soft hose 200, and tightened with a predetermined torque with respect to the repair pipeline attaching portion 111 (fourth step). Since the soft hose 200 is more easily deformed than a regular rubber tube, the torque when tightening the hose band 130 is set to be larger than the torque when tightening the regular rubber tube as long as the soft hose 200 is not damaged.

In the present embodiment, since the two recesses 113A and 113B are formed in the repair pipeline attaching portion 111, the hose band 130 is disposed at each position corresponding to the recesses 113A and 113B on the outer periphery of the soft hose 200. Then, it is tightened with a predetermined torque with respect to the repair pipeline attaching portion 111. In the case where three or more recesses 113 are formed in the repair pipe attachment portion 111, the hose band 130 is disposed on the outer periphery of the soft hose 200 at a position corresponding to the two or more recesses 113 at least from the center in the longitudinal direction. What is necessary is just to be fastened by the predetermined torque with respect to the pipe-line attaching part 111. FIG. Of course, the hose band 130 may be arranged on the outer periphery of the soft hose 200 at a position corresponding to all the concave portions 113.
As a result, the soft hose 200 is firmly fixed to the intermediate connection fitting 110, so that the soft hose 200 falls off due to the water pressure when the refrigerant flows, or the refrigerant leaks from the gap between the soft hose 200 and the intermediate connection fitting 110. Can be effectively prevented.

Next, as shown in FIG. 8, the soft hose 200 is folded outward in the vicinity of the end on the center side of the repair pipeline attaching portion 111 (fifth step).
Then, as shown in FIG. 8, the hose band 140 is attached to the outer peripheral surface of the folded portion of the soft hose 200, and is tightened with a predetermined torque with respect to the repair pipeline attaching portion 111 (sixth step). The torque at the time of tightening the hose band 140 is also made larger than the torque at the time of tightening the regular rubber tube as long as the soft hose 200 is not damaged, as in the case of tightening the hose band 130.

The soft hose 200 is easier to handle than a regular rubber tube, but it is easily deformed, so that the soft hose 200 has poor adhesion to the intermediate connection fitting 110. For this reason, in the same fixing method as a regular rubber tube, that is, the method of fixing the soft hose 200 without folding back, the soft hose 200 may fall out of the intermediate connection fitting 110 when the refrigerant flows through the soft hose 200.
Therefore, in the present embodiment, after the soft hose 200 is folded back, the hose band 140 is attached to the outer peripheral surface of the folded portion and tightened.

On the outer peripheral surface of the folded portion of the soft hose 200, in FIG. 8, the hose band 140 is attached to one recess 113A among the two recesses 113A and 113B formed in the repair pipe attachment portion 111. As shown in FIG. 9, the hose band 140 may be attached to the two recesses 113A and 113B. In this case, since the soft hose 200 is more firmly fixed to the intermediate connection fitting 110, the soft hose 200 drops off due to the water pressure when the refrigerant flows, or the refrigerant leaks from the gap between the soft hose 200 and the intermediate connection fitting 110. It can prevent more effectively.
As described above, when the plurality of recesses 113A and 113B are formed in the repair pipe attachment portion 111, at least one or more from the center in the longitudinal direction on the outer peripheral surface of the folded portion of the soft hose 200, that is, at least in the recess 113A. It is preferable to tighten the hose band 140 on the outer peripheral surface of the folded portion of the corresponding soft hose 200. As a result, the end of the folded portion at the center of the intermediate connecting fitting 110 (the left end of the folded portion in FIGS. 8 and 9) is curled and the soft hose 200 is prevented from easily falling off the intermediate connecting fitting 110. Can do.
Furthermore, when a plurality of recesses are formed in the repair pipe attachment portion 111, the outer peripheral surface of the soft hose 200 (the outer peripheral surface of the outermost layer 204 of the soft hose 200) and the folded portion of the soft hose with respect to each recess. By tightening the hose band on both of the outer peripheral surfaces (the peripheral surface of the portion where the inner peripheral surface of the innermost layer 201 of the soft hose 200 is folded back), the soft hose 200 can be more firmly fixed to the intermediate connection fitting 110. it can. For example, in FIG. 9, the hose bands 130 and 140 are fastened to the soft hose 200 in both of the two recesses 113A and 113B. Further, when the repair pipeline attaching portion 110 has three recesses (not shown), both the hose bands 130 and 140 may be fastened to the soft hose 200 at a position corresponding to each recess.
Thereby, it is possible to more effectively prevent the soft hose 200 from dropping off due to the water pressure when the refrigerant is flowed or the refrigerant leaking out from the gap between the soft hose 200 and the intermediate connection fitting 110. Further, since the hose band 140 is attached to the positions corresponding to all the concave portions compared to the case where the hose band is not tightened at the positions corresponding to the concave portions on the outer peripheral surface of the folded portion of the soft hose 200, the softness at the folded portion is reduced. Since the end portion of the hose 200 (the right end portion of the folded portion in FIGS. 8 and 9) can be prevented more effectively, the soft hose 200 can be more easily removed from the intermediate fitting 110. It can be effectively prevented.

  Thus, in the repair method for the return pipe according to the present embodiment, the damaged rubber pipe (120A) is connected to the damaged rubber pipe (120A) of the two rubber pipes (120A, 120B). The first step of removing from the intermediate connection member (intermediate connection fitting 110), and the sealing material on the outer peripheral surface of the repair pipe attachment portion (111) on the side where the damaged rubber pipe (120A) of the intermediate connection member (110) is removed A second step of applying a cut, and forming a notch (S) of a predetermined length at the end of a soft hose (200) that is flexible and water-impermeable and can be stored in a flat state. ) And a third step of extrapolating the soft hose (200) until the end of the soft hose (200) exceeds the center side end of the repair pipe attachment portion (111) on the side where the sealing material is applied, No. on the outer surface of the hose (200) The fourth step of attaching the tightening bracket (hose band 130) and tightening with a predetermined torque with respect to the repair pipe mounting portion (111), and soft near the center side end of the repair pipe mounting portion (111) The fifth step of folding the hose (200) outward, and the second fastening bracket (hose band 140) is attached to the outer peripheral surface of the folded portion of the soft hose (200), with respect to the repair pipe attachment part (111) And a sixth step of tightening with a predetermined torque.

  In addition, the intermediate connection portion 100 of the return pipe after repair includes a pipe-like intermediate connection member (intermediate connection fitting 110) having pipe connection portions (111, 112) for attaching the pipe lines to both ends. A flexible, water-impermeable, and flat-storable soft material that is attached to one conduit attachment part (111) and folded outward through a notch of a predetermined length formed at the end. A hose (200), a first fastening fitting (hose band 130) disposed on the outer peripheral surface of the unfolded portion of the soft hose (200) and fastened to the pipe line attachment portion (111), and the soft hose A second fastening bracket (hose band 140) which is arranged on the outer peripheral surface of the folded portion of (200) and is fastened to the pipe fitting part (111), a pipe fitting part (111) and a soft hose ( 200) and Comprising sealing portion interposed between the (150), the.

In this embodiment, when damage is found in the return pipe, a commercially available soft hose (trade name: Heavy Duty Sunny Hose) that can be easily obtained is applied instead of a regular rubber pipe. The return pipe can be repaired in a day. In addition, by tightening the hose bands 130 and 140 at predetermined positions including the outer peripheral surface of the folded portion of the soft hose 200, a watertight connection structure can be reliably configured.
As described above, according to the present embodiment, by using the soft hose 200 instead of the regular rubber pipe, it is possible to quickly repair when damage is found in a part of the return pipe. Accordingly, the safety and reliability of the underground power transmission network are greatly improved.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.
For example, in the present embodiment, the repair process in the case where the rubber tube 120A connected to the right-side pipe attachment portion 111 of the intermediate connection fitting 100 is damaged has been described, but the left-side pipe attachment portion 112 is connected. The repair process when the rubber tube 120B is damaged is the same. Further, the present invention may be applied when the two rubber pipes 120A and 120B connected to the pipe line attachment portions 111 and 112 are damaged and repaired at a time.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

100 intermediate connection part 110 intermediate connection metal fitting (intermediate connection member)
111 Pipe line attachment (repair pipe line attachment)
112 Pipe fitting portions 113, 113A, 113B Concave portion 114 Tapered portion 115 Central portion 120, 120A, 120B Rubber tube 130 Hose band (first fastening bracket)
140 Hose band (second clamp)
150 Sealing part 200 Soft hose

Claims (11)

Refrigerant flow path for cooling system of underground power transmission network, comprising intermediate connection part in which two rubber pipes are connected via a pipe-like intermediate connection member having a pipe attachment part for attaching a pipe line to each of both ends A return pipe repairing method comprising:
A first step of removing a damaged rubber tube from the intermediate connecting member to which the damaged rubber tube is connected;
A second step of applying a sealing material to the outer peripheral surface of the repair pipe attachment portion on the side where the damaged rubber pipe of the intermediate connecting member is removed;
It has flexibility and water impermeability, can be stored in a flat state, and forms a notch of a predetermined length at the end of a soft hose having a water impermeable layer made of synthetic resin and a reinforcing layer made of synthetic fiber , A third step of extrapolating the soft hose until the end of the soft hose exceeds the central end of the repair conduit mounting portion on the side where the sealing material of the intermediate connecting member is applied;
A fourth step of attaching a first fastening bracket to the outer peripheral surface of the soft hose and fastening the repair hose with a predetermined torque with respect to the repair pipe attachment part;
A fifth step of folding the soft hose outward in the vicinity of the center side end of the repair conduit attaching portion;
And a sixth step of attaching a second fastening bracket to the outer peripheral surface of the folded portion of the soft hose and tightening the repair pipe attachment portion with a predetermined torque. Method. A plurality of ring-shaped recesses are formed on the outer peripheral surface of each of the pipe attachment portions,
In the fourth step, the first fastening bracket is tightened against at least two from the center in the longitudinal direction among the plurality of concave portions formed in the repair pipeline attaching portion,
In the fifth step, the soft hose is folded back so that at least one of the plurality of recesses formed in the repair pipeline attaching portion is covered with the soft hose at least from the center in the longitudinal direction,
In the sixth step, the second fastening fitting is fastened to at least one of the plurality of concave portions formed in the repair pipeline attaching portion from the center side in the longitudinal direction. Item 6. The return pipe repair method according to Item 1.   The return pipe repair method according to claim 2, wherein the pipe line attachment part has a taper part whose diameter increases toward the center in the longitudinal direction between the plurality of concave parts. The return pipe repair method according to any one of claims 1 to 3 , wherein a length of the cut is equal to a length of a folded portion of the soft hose. The incision method of repairing return pipe according to claim 1, any one of 4, which comprises 2 to 4 dividing the soft hose in the circumferential direction. An intermediate connection portion of a return pipe constituting the refrigerant flow path of the cooling system of the underground power transmission network,
A pipe-like intermediate connecting member having a pipe attachment portion for attaching the pipe to each of both ends;
A flexible hose that is attached to at least one of the conduit attachment portions and is folded outward through a notch of a predetermined length formed in an end portion and has flexibility and water impermeability and can be stored in a flat state. When,
A first fastening member disposed on an outer peripheral surface of the unfolded portion of the soft hose, and fastened to the pipe attachment portion;
A second fastening member disposed on the outer peripheral surface of the folded portion of the soft hose, and fastened to the pipe line attachment portion;
An intermediate connection part of a return pipe, comprising: a seal part interposed between the pipe line attachment part and the soft hose. A plurality of ring-shaped recesses are formed on the outer peripheral surface of each of the pipe attachment portions,
The soft hose covers at least one of the central sides in the longitudinal direction of the plurality of recesses formed in the pipe line attachment portion on the connected side with a folded portion,
The first fastening brackets are arranged corresponding to at least two of the plurality of recesses from the center side in the longitudinal direction,
The intermediate connection part of a return pipe according to claim 6 , wherein the second fastening metal fitting is arranged corresponding to at least one of the plurality of recesses from the central side in the longitudinal direction. 8. The intermediate connection portion of the return pipe according to claim 7 , wherein the pipe line attachment portion has a taper portion whose diameter increases toward the center in the longitudinal direction between the plurality of concave portions. The intermediate connection portion of the return pipe according to any one of claims 6 to 8 , wherein the soft hose includes a water-impermeable layer made of a synthetic resin and a reinforcing layer made of a synthetic fiber. The return pipe intermediate connection part according to any one of claims 6 to 9 , wherein a length of the cut is equal to a length of a folded portion of the soft hose. The cuts, the intermediate connection portion of the return pipe according to any one of claims 6 to 10, characterized in that two to four dividing the soft hose in the circumferential direction.

Images