JPS63247506A - Boiler heat-transfer tube cleaning inspection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a boiler heat exchanger tube cleaning and inspection device, and particularly to a boiler heat exchanger tube suitable for automatically cleaning and inspecting a group of heat exchanger tubes in a large boiler device. Regarding cleaning inspection equipment.

[Conventional technology]

Large boilers, such as those used in thermal power plants, are
It has a configuration as shown in FIG. 6, in which a furnace 2 is disposed on a protective wall 1, a burner 3 is provided on the lower side wall of the furnace 2, and heat transfer tube blocks 4 and 5 are provided in the upper and outlet sides of the furnace. It is arranged. Further, a hopper 6 for storing combustion ash is provided at the bottom of the furnace 2. The heat exchanger tube block 4 is
For example, they are a reheater and a superheater, and are made up of heat exchanger tube groups ASB with different pipe intervals. Moreover, the heat exchanger tube block 5 is, for example, a superheater or a energy saver.

As shown in FIG. 7, the heat exchanger tube blocks 4 and 5 are arranged in a direction (horizontal direction) perpendicular to the flow direction of combustion gas. Each block supports heat exchanger tubes 7 in which both ends of straight tubes are connected by U-shaped tubes with spacers 8, and both ends of each block are fixed by water walls 9. A header 10 is connected to the intake section and outlet section of the heat exchanger tube 7. In order to effectively obtain heat from the combustion gas, the heat exchanger tube groups A and B arranged in the hot gas section where the temperature of the combustion gas is high have a reduced heat transfer area, and The heat transfer area is increased in the low-temperature gas section.

This state is shown in Fig. 8, where the pipe spacing in the direction perpendicular to the gas flow direction becomes narrower as it becomes downstream of the gas flow (distance 1) a>llb>1)C) For example, the intervals 1)a and llb between blocks A and B of the heat exchanger tube block 4 are approximately 300 mm and approximately 150 mm, and the interval 1)c between the heat exchanger tube blocks 5 is approximately 100 mm. Note that the diameter of the heat exchanger tubes 7 is approximately 50 mm.
~60mm.

In the above configuration, when gas or liquefied fuel is combusted in the furnace 2 by the burner 3, heat exchange occurs as the combustion gas sequentially passes through the heat transfer tube blocks 4 and 5. Low-temperature steam or water is supplied to the heat exchanger tube blocks 4 and 5, and steam heated by heat exchange is taken out.
It is supplied to a steam turbine (not shown). The combustion gas in the furnace 2 after heat exchange with the heat exchanger tube blocks 4 and 5 is sent to a dust removal device or the like.

By the way, boilers for thermal power plants are required to be periodically inspected based on the law (Electricity Business Law). When carrying out periodic inspections, it is necessary to stop the operation of the boiler, so it is common to inspect and clean items other than the inspection items in conjunction with this inspection. Among these inspections, the inspection and cleaning of the boiler heat transfer tube group is performed manually by having a worker enter the boiler, and cleaning is generally performed by washing with water.

As mentioned above, the occurrence of heat transfer tube pinches differs depending on the installation location, but because the high-temperature parts are relatively spaced apart, workers can crawl between groups of heat transfer tubes to inspect and clean them. However, in the low-temperature gas section, the intervals between the heat transfer tubes 7 are narrow, so it is necessary to insert only the worker's hand into the interval 1) between the groups of heat transfer tubes 7 and perform inspection, measurement, and cleaning work only within the reachable area. Inspection, measurement, and cleaning work is performed after cutting a part of the group of heat transfer tubes 7 to widen the interval between the heat transfer tubes 7.

Furthermore, in a boiler that performs oil-fired combustion, scale adheres heavily to the outside of the heat exchanger tubes 7. The main component of the attached scale is N az S O4, and in addition, Sto
Contains trace amounts of w and heavy metals.

If such scale adheres to the heat transfer tube 7, the heat transfer characteristics will deteriorate, and it is necessary to remove this scale during periodic inspections. By the way, Na! which is the main component of the scale!
304 exhibits hydrophilicity and has the property of being easily soluble in water. For this reason, conventionally, a water washing method as shown in FIG. 9 has been used during periodic inspections.

Figure 9 shows the conventional boiler heat transfer tube cleaning method.
A spray nozzle 12 is arranged on the ceiling of the
2, water is supplied from a water supply pump I4 via piping 13 and water is sprayed from a nozzle 12, or water is supplied from a high-pressure pump 16 to a jet flushing gun 15 held by the worker and water is sprayed. Cleaning water is stored in the water supply pump 14 and the high-pressure pump 16, and is sprayed onto the heat transfer tubes 7 from the nozzle 12 or the jet water gun 15. The sprayed cleaning water flows along the furnace 2 and passes through the cleaning water (washing water) discharge pipe 17.
is discharged to a treatment tank 18 for neutralization treatment.

However, since the aqueous solution in which Na z S Oa is dissolved in the treatment tank 18 has strong acidity with a pH of about 2 to 3, the boiler itself (furnace wall, etc.) is easily damaged by acid corrosion due to the aqueous solution that flows down.

As a method for preventing this, a curing material 20 is required for the purpose of preventing the aqueous solution from entering the inner wall of the boiler furnace 2 where cleaning water (water-soluble?&) is likely to enter or accumulate.

For example, areas where cleaning water (aqueous solution) easily enters or accumulates include areas where there are pipes that pass through the furnace wall laterally, and furnace wall openings (burners, furnace monitoring TV, gas pressure measurement, etc.)
Therefore, the gaps in the furnace wall at the penetration part are filled with polyurethane, etc. to eliminate the gap, and for the opening in the furnace wall, a vinyl sheet is placed on the inside of the furnace wall to prevent the aqueous solution from directly touching the furnace wall tube. This is the curing material 20. When this curing material 20 is stretched inside the furnace 2, scaffolding is erected inside the furnace 2.

[Problem that the invention seeks to solve]

However, in the conventional boiler heat transfer tube cleaning inspection method,
Because workers enter the furnace 2, which has a poor environment, to directly inspect and clean it, it is difficult to ensure safety, the work is poor, and it takes a lot of time and time. In particular, it takes about 10 days to assemble scaffolding inside the furnace for a 500,000 kW class boiler, and about 5 days to dismantle and remove it, resulting in the suspension of boiler operation during this period. is a huge amount when converted into the amount of power generated. In addition, inspection and cleaning work requires work in highly dusty environments and extremely high scaffolding, making inspection and cleaning work extremely difficult and dangerous. Since it is necessary to shorten the cleaning time, a large number of people are required at the same time, and accidents are more likely to occur.

Furthermore, recently, the operating pattern of boilers has been changing to high-load varying operations and daily start-stop operations, which requires higher inspection accuracy and tends to increase the time and number of people devoted to inspections.

The purpose of the present invention is to solve the problems of the prior art described above,
It is an object of the present invention to provide a boiler heat exchanger tube cleaning and inspection device capable of automating and centrally controlling inspection, cleaning, etc. of boiler heat exchanger tubes.

[Means for solving problems]

In order to achieve the above object, the present invention provides a working robot that moves between groups of heat transfer tubes, and a service section that is connected to the working robot via a control line and a dust collection hose and that controls the working robot from outside the furnace. It has been established.

[Operation] The robot working inside the furnace moves on its own while cleaning or inspecting the heat transfer tube from one end to the other under the control of the service section. Control of the work robot is performed via the service section based on position information and inspection information from the outside work robot, or in accordance with instructions from an operator. The service section can control and manage multiple work robots, which can significantly reduce the number of workers and labor.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

A stage 21 is installed outside the furnace at the height of the installation position of the heat transfer tube block of the furnace 2, allowing passage of workers and temporary installation of various devices. Further, in order to allow workers to exit from the stage 21 into the furnace 2, a manhole 22 is provided on the side wall of the furnace.

Work robots 23 are installed between the heat exchanger tube blocks 4 to be inspected or cleaned, and the work robots 23 move horizontally along the heat exchanger tubes. By using a plurality of them, work efficiency is increased, and the boiler It is possible to shorten the period during which the plant is out of operation. A power unit 24 is installed on the upper surface of the heat exchanger tube block 4 to transmit electric power or power to one or more working robots 23 .

This power unit 24 functions as a distributor for a configuration in which each work robot has a built-in motor for running. Further, for a working robot that does not have a built-in motor, the power unit 24 is equipped with a motor and is configured to mechanically transmit this rotational force to the working robot 23.

Note that the power unit 24 includes a drive mechanism that can move in all directions (left, right, front and back) in accordance with the movement of the working robot 23.

Further, between the power unit 24 and the working robot 23, there is a dust collection hose and cable for collecting scale peeled off or brushed off from the heat transfer tube 7 by a brush (described later) provided on the working robot 23 and discharging it to the outside of the furnace. An integrated cable hose 25 is connected. A bath member 26 that integrates a power cable, various signal cables, and a dust collection hose is connected to the power unit 24 and is drawn out of the furnace 2 through the manhole 22 .

The power cable and signal cable in the pulled-out connecting member 26 are connected to the service section 27, and the dust collection hose is connected to the dust collection section 2.

The service section 27 and the dust collection section 28 are installed on the stage 21, and since casters are attached to the bottom of each section, they can be easily moved. The service section 27 is equipped with a microprocessor, a printer, a CRT display, etc., and supplies power and control signals to the power unit 24 and the work robot 23, and receives sensor information, inspection information, etc. from each of the power unit 24 and the work robot 23. 23 control, and also aggregates inspection results, etc., and displays or records them.

In the above configuration, the power unit 24 is placed on the top surface of the heat exchanger tube group to be worked in the furnace 2 whose operation has been stopped,
A working robot 23 is installed between a group of heat exchanger tubes near this power unit 24. A connecting member 2 that connects a cable and a hose between the working robot 23 and the power unit 24 and is further drawn into the furnace 2 through the manhole 22.
6 to the power unit 24. A connecting member 26 outside the furnace 2 is connected to a service section 27 and a dust collection section 28 installed on the stage 21.

In this state, turn on the power to the service section 27,
When the start button is pressed, each of the working robots 23 starts running and cleans or inspects a plurality of heat transfer tubes at the same time.

Inspection information and sensor outputs indicating the operating state of the work robot 23 while it is moving are sequentially sent to the service section 27, and are used for subsequent control and report creation of inspection results.

When each working robot 23 moves to the end of the heat exchanger tube group,
After automatically descending by the inspection width (or cleaning width), the power unit 24 automatically travels in the same direction in conjunction with the travel of the zero-work robot 23, which automatically travels in the opposite direction. When the work robot 23 is cleaning, the removed scale is transferred to the dust collection section 28 via the dust collection hose.
are collected in. A vacuum device is provided within the dust collection section 28 to suck up scale.

When the work robot 23 moves to the lower end of the heat transfer tube group by repeating the above operations, the work robot throat 23 and the power unit 24 stop all operations, and the dust collection section 28 also stops. Here, the work robot 23 and power unit 24 are manually moved to another group of heat exchanger tubes to be worked on, operated again, and cleaned and inspected.

In addition, in the above description, the case where the heat exchanger tube group is placed horizontally is taken as an example, but the structure can be similarly configured even when the heat exchanger tube group is placed vertically. In this case, it is necessary to have a configuration that includes a working robot and a drive mechanism that vertically moves up and down along the heat transfer tube.

Next, the configuration of the working robot 23 will be described, but here only the configuration for a group of horizontally arranged heat exchanger tubes will be described.

FIG. 2 is a perspective view showing details of the working robot 23.

The power unit 24 is placed on the upper surface of the horizontally arranged heat exchanger tube block 30, and the cable 26a and hose 26
A connecting member 26 consisting of b is connected. The power unit 24 is provided with a storage section 31 in which the working robot 23 is stored and moved, and long-shaft wheels 32 for moving left and right and forward and backward are disposed at both ends at the bottom. Furthermore, the power unit 24 has a work opening bot 2 in the support part of the long shaft wheel 32.
In addition to the control unit 33 for controlling the operation of the motors, etc. of the long-shaft wheels 32 and 3, the working robot in the storage unit 31 is lifted up and stored, or the working robot in a descending state is lifted up and stored in the storage unit 31. Elevating devices are provided as necessary.

The long shaft wheel 32 is provided with a spiral protrusion (or groove) on its surface. The long shaft wheels 32 are 4 in total, 2 each on the left and right and front and back.
A total of two trees are attached, one on each side of the book. In the case of four-wheel wheels, the spiral directions are opposite to each other with respect to adjacent long-shaft wheels, and in the case of two wheels, the spiral direction is opposite to the other end.

With such a configuration, the direction of torque generation generated by the spiral protrusion can be changed by rotating all of the long shaft wheels 32 in the same direction or rotating them in opposite directions. You can freely move forward and rightward.

The work robot 23 includes a drive mechanism for distributing power mechanically transmitted from a motor or a motor built in the power unit 24 to long-shaft wheels 36 and 37, and a drive mechanism for creating cracks in the removed scale using a laser beam. The main component is a driving section 35 that includes a laser generator.

Adjacent to the drive unit 35, long-shaft wheels 36 and 37 to which power from a drive mechanism or a motor is transmitted are arranged back to back, and are arranged between the heat exchanger tube groups so as to press the heat exchanger tubes into contact with each other. On the outside of the long shaft wheels 36 and 37, sensors 38 are installed to measure the thickness of scale attached to the heat transfer tubes.
A scale collection mechanism 39 that sucks up the scale removed by the brushes and a rotating brush machine 40 that removes the scale adhering to the surface of the heat exchanger tube are installed. brush machine 40
is rotated by a motor (not shown).

A cable hose 25 is attached to the upper end of the scale collection mechanism 39.
A dust collection hose 41 directly connected to the hose is connected. As the sensor 38, for example, an ultrasonic thickness measuring device can be used.

The long shaft wheels 35 and 36 are provided with spiral protrusions on their surfaces as shown in FIG. is held without falling.

Next, the operation of the configuration shown in FIG. 2 will be explained. First, the power unit 24 in which the working robot 23 is housed in the storage section 31 is R'H'ed between the heat exchanger tube groups to be worked, and the connecting members 26 of the service section 27 and the dust collection section 28 are connected.

Next, the operating panel of the service section 27 is operated to lower the working robot to the working position. At this time, the long-shaft wheels 36 and 38 are driven so as to approach each other during the period from the start of descent to the set position, and as soon as they reach the set position, they are driven in a direction to separate them, so that the two groups facing each other are driven. While pressing the heat exchanger tube block, the spiral protrusion 42 is engaged with the heat exchanger tube 7 as shown in FIG.

In this state, power is transmitted from the drive section 35 of each of the long-shaft wheels 36, 37. For example, when a clockwise rotational force is applied, looking only at the left and right movements in FIG. It tries to move to the right, but the long shaft wheel 36 (left), the long shaft wheel 3'7 (left), and the long shaft wheel 36 (right) are rotating in the same direction as the long shaft wheel 37 (right). The amount of horizontal movement to the left in the figure by the long-shaft wheel 36 and the long-shaft wheel 3
The amount of horizontal movement to the right in the figure by 7 is balanced and the amount of left and right movement is canceled out to zero, resulting in a stationary state.

In other words, as a result, the amount of horizontal movement of the long-shaft wheels 36 and 37 becomes negligible, resulting in mere rotational movement in a stationary position.

Therefore, in FIG. 5, even if the long shaft wheels 36, 37 are rotated clockwise, they will not move to the left or right in FIG. On the other hand, when a clockwise rotational force is applied to the long-shaft wheels 36 and 37, all the long-shaft wheels 36 and 37 gradually rise upward along the interval between the heat transfer tubes 7 due to the spiral protrusion 42 of the cloth wrap. become. .

In this way, the working robot 23 ascends within the space between the heat transfer tubes 7 simply by rotating the long shaft wheels 36 and 37 clockwise. The work robot 23 is lowered by rotating the shaft-long wheels 36, 37 in the opposite direction. Further, horizontal movement is achieved by applying a clockwise rotational force to the long-shaft wheel 36 and a counterclockwise rotational force to the long-shaft wheel 37, as shown in FIG. 5, from right to left in the figure. Move horizontally. Further, movement from left to right can be realized by performing the operation opposite to the above.

In addition, for vertically arranged heat exchanger tubes, power unit 2
4 is difficult to install, it is necessary to incorporate it into the robot or to distribute its functions to the service section 27. Therefore, in this case, the configuration is such that no separate power unit is provided.

〔Effect of the invention〕

As described above, according to the present invention, a working robot is installed inside the furnace, and it is controlled and managed from the outside to perform automatic inspection and automatic control from outside the furnace, thereby eliminating the need for manual inspection and cleaning work. , safety (prevention of falling accidents, etc.), improvement of the working environment, and work efficiency can be dramatically improved.

In this way, there is no need to inspect and clean the heat transfer tubes manually, so there is no need to cut the heat transfer tubes, install and remove spray water piping, assemble and remove scaffolding inside the furnace, and treat wastewater. The period can be significantly shortened.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
Perspective views showing details of the working robot in Figures 3 and 4.
The figure is a front view and a side view showing details of the long shaft wheel in Figure 2,
Figure 5 is an explanatory diagram showing the movement of the working robot, Figure 6 is a front view showing the schematic configuration of a large boiler, Figure 7 is a front view showing an example of the configuration of a heat exchanger tube block, and Figure 8 is a heat exchanger tube block. FIG. 9 is an explanatory diagram showing a conventional method of cleaning a heat transfer tube block. 2... Furnace, 4.5... Heat exchanger tube block, 7... Heat exchanger tube, 21... Stage, 22... Manhole, 23... Working robot, 24... Power unit, 25...
... Cable hose, 26 ... Connection member,
27...Service section, 28.Old dust collection section, 32.36.37...Shaft length wheel, 38...Sensor, 39...・Scale collection mechanism, 40... Brush machine, 42...
・Spiral projection. Agent Patent Attorney Masaru Nishimoto - Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Announcement Popular Phrases

Claims (5)

[Claims] (1) A work robot that cleans or inspects the heat transfer tubes while moving between groups of heat transfer tubes in the boiler heat transfer tubes that are located in the boiler furnace and constitutes the superheater, reheater, etc.; A boiler heat exchanger tube cleaning and inspection device comprising a service section to which a cable for supplying power and exchanging information is connected to control the working robot from outside the furnace and to process data. (2) A dust collecting section provided outside the furnace and the working robot are connected by a dust collecting hose, and the scale removed by the working robot is sucked into the dust collecting section. Boiler heat exchanger tube cleaning and inspection device described in section 1). (3) A power unit is provided on the top surface of a group of heat exchanger tubes near the movement range of the working robots and controls one or more of the working robots under the management of the service section. The scope of claim No. (
Boiler heat exchanger tube cleaning and inspection device described in section 1). (4) The boiler heat exchanger tube cleaning and inspection device according to claim (3), wherein the power unit moves on the installation surface alone or in conjunction with the movement of the work robot. (5) Boiler heat exchanger tube cleaning and inspection as set forth in claim (3) or (4), wherein the power unit has a lifting device that lifts and lowers the working robot to an arbitrary working position. Device.