JPH0438319Y2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a maintenance device for heat transfer tubes in a heat exchanger of a nuclear power plant.

<Conventional technology> In general, maintenance work for heat transfer tubes in steam generators (heat exchangers) of nuclear power plants includes brushing and cleaning of the inner surfaces of the heat transfer tubes, which cover an area up to 120 mm from the tube sheet surface. It is being implemented. However, in the conventional heat exchanger tube maintenance work method, as shown in FIG. A tool head 5 for brushing or cleaning that is replaceable inside the guide tube 4, a torque cable 6 with the tool head 5 attached to its tip, and a torque cable 6 that guides the end face of the guide tube 4.
A maintenance tool consisting of a tool rotation motor that rotates the heat exchanger tube 2 is inserted, and a worker holds the maintenance tool while rotating the tool rotation motor 7 while performing maintenance work inside the heat exchanger tube 2.

<Problems to be solved by the invention> In the heat exchanger tube maintenance work using the conventional method described above,
As workers perform manual work such as inserting and removing maintenance tools, there are variations in the construction range in the direction of the pipe axis, and maintenance accuracy and quality are inconsistent, such as the work being carried out beyond the required range. There is. Furthermore, since workers work for long periods of time near the manhole of the steam generator, there are problems such as an increased amount of radiation exposure and a high degree of danger.

<Means for Solving the Problems> The present invention was proposed in order to solve the conventional problems, and it is possible to uniformly perform maintenance within the tube axis direction within the heat transfer tube using a maintenance tool, and to
By repeatedly performing work back and forth in the direction of the pipe axis within the maintenance work area, workers do not need to approach the vicinity of the steam generator manhole except for replacing tool heads, and the aim is to significantly reduce radiation exposure. The purpose is to provide a maintenance device for heat exchangers.

<Example> Hereinafter, a heat exchanger tube maintenance device according to the present invention will be described in detail based on an example shown in the drawings. Fig. 2 is a schematic configuration diagram showing a heat exchanger tube maintenance device according to the present invention, and Fig. 3 is a top view showing the main parts of Fig. 2, in which 1 is a steam generator, 2 is a heat exchanger tube, and 3 is a steam generator. A guide device installed in the water chamber of the generator 1; 4 a guide tube held in the guide device 3; 5 a replaceable tool head for brushing or cleaning;
6 is a torque cable with a tool head 5 attached to its tip, and 7 is a tool rotation motor for rotating the torque cable 6. The tool head 5 is rotated by a tool rotation motor 7 via a torque cable 6, and a feeding device that inserts and pulls the tool head 5 into and out of the heating tube 2 transmits power to the tool head 5 together with the torque cable 6. An insertion/extraction cylinder 8 that is inserted into or pulled out of the heat tube 2, and a carriage 10 that holds and guides this cylinder 8.
and a guide shaft 11 for guiding the carriage 10.
It is comprised of a stopper cylinder 9 and a strip link 13 that define the lower limit position of the tool head 5 for repeated reciprocation within the heat exchanger tube 2, and a casing 12 that holds the entire tool.

Maintenance work using the conduit maintenance device configured as described above is performed in the following steps.

That is, first, the heat exchanger tube maintenance device according to the present invention is installed near the manhole of the steam generator 1, and is used after being guided to a predetermined address by the guide device 3, and is used while the new internal device 3 is being moved. After the maintenance work, the tool head 5 is pulled out from the heat exchanger tube 2 into the guide tube 4, and is held in a position where movement of the guide device 3 is not hindered. Therefore, when carrying out maintenance work on the heat exchanger tube 2 to be maintained, the piston rod of the stopper cylinder 9 is brought into the contracted and released state while the tool rotation motor 7 is rotated, and the piston rod of the insertion/extraction cylinder 8 is The tool head 5 is inserted into the heat transfer tube 2 by an insertion operation in which the heat exchanger tube 2 is contracted, and the tool head 5 is set at the upper and lower working positions within the tube.

Subsequently, by extending the piston rod of the stopper cylinder 9 and performing a stop operation, the stop link 13 is actuated to become a stopper. In this state, when the piston rod of the insertion/extraction cylinder 8 is extended and pulled out, the carriage 10 fixed to the piston rod portion of the cylinder 8 is pulled out to a position where it abuts the stop link 13, thereby removing the lower limit of the pipe. The tool head 5 is set at the position. Therefore, the piston rod of the insertion/extraction cylinder 8 is in the insertion operation position where it is contracted, and the piston rod is extended and the carriage 1 is
Cyclic construction work can be performed by repeatedly moving back and forth between the positions where the 0 hits the stop link 13 and stops.

After the cycle construction work is completed, the piston rod of the stopper cylinder 9 is contracted and released, and the piston rod of the insertion/extraction cylinder 8 is extended and pulled out, thereby completing the prescribed heat transfer tube maintenance work.

In the embodiment of the present invention, a case is explained in which the tool head 5 is inserted into the heat exchanger tube 2 while being rotated by the tool rotation motor 7 via the torque cable 6. The rotation operation may be performed after the tool head 5 is inserted through the entire stroke to the construction position.

<Effect of the invention> As described above in detail based on the embodiment shown in the drawings, according to the heat exchanger tube maintenance device of the present invention, the tool head is moved in the tube axis direction within the heat exchanger tube. It can be easily inserted into or pulled out from the specified maintenance equipment in the heat exchanger tube, and the tool head can be repeatedly moved back and forth between the specified upper and lower limit positions in the heat transfer tube. It has a simple structure made up of flexible parts and is easy to handle, and can be automated without placing any burden on the operator, except when replacing the tool head.

In addition, by using the device according to the present invention, some of the heat exchanger tube maintenance work that conventionally relied on human hands can be performed remotely rather than manually, eliminating the need for manual work and reducing the number of workers. Since the amount of radiation exposure is significantly reduced, it is extremely useful from the standpoint of safety, and furthermore, maintenance accuracy and quality can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a conventional heat exchanger tube maintenance work method, Fig. 2 is a schematic configuration diagram showing a heat exchanger tube maintenance device for a heat exchanger according to the present invention, and Fig. 3 shows the main parts of Fig. 2. FIG. In the drawing, 1 is a steam generation tube, 2 is a heat exchanger tube, 3 is a guide device, 4 is a guide tube, 5 is a tool head,
6 is a torque cable, 7 is a tool rotation motor, 8
1 is an insertion/extraction cylinder, 9 is a stopper cylinder, 10 is a carriage, 11 is a guide shaft, 12 is a casing, and 13 is a stop link.

Claims (1)

[Scope of utility model registration request] A tool rotation motor that rotates a tool head that performs surface maintenance work inside a heat exchanger tube via a torque cable, a carriage that supports the motor, and a trolley equipped with a guide shaft that is slidably fitted to the carriage. , an insertion/extraction cylinder interposed between the dolly and the carriage and reciprocating the tool head in the tube axis direction of the heat transfer tube through the reciprocating motion of the carriage; and a stock cylinder provided on the dolly. A heat exchanger tube maintenance device for a heat exchanger, comprising a stopper cylinder and a stoplink connected to the stopper cylinder and retracted onto the movement path of the carriage to determine a lower limit stop position of the tool head. .