RU2692748C2 - Appliance and method for cleaning heat exchanger inner zone - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to means of cleaning the inner zone of a heat exchanger, particularly steam generator (2) of a nuclear power plant. In compliance with this invention, high-pressure water jets comprises manipulator (5) installed in vertical corridor passing between bundles of heat exchanger tubes, and elevator (4) connected with said manipulator (5). Manipulator (5) has at least one rotary nozzle (8, 8.1, 8.2, 8.3, 8.4), installed with possibility of rotation around rotary axis (S1, S2, S3, S4), orientation of which is matched with distance between pipes in tube bundle (3) of heat exchanger.EFFECT: technical result is higher efficiency of cleaning heat exchangers with pipes passing in horizontal direction.18 cl, 3 dwg

Description

The invention relates to a device and method for cleaning the inner zone of the heat exchanger, in particular, the steam generator of a nuclear power plant, with high-pressure water jets.

Cleaning of heat exchangers and steam generators of a nuclear power plant is usually carried out chemically or mechanically using low pressure water jets.

Further, a device for cleaning the inner zone of a steam generator with high-pressure water jets is known, for example, from patent EP 1170567 B1. To remove lime sludge, a flexible peak with a wash head, which has a flow channel of a high-pressure water pipeline, is introduced into the steam generator in the horizontal direction through a small hatch located in the area of the tube sheet. Cleaning of the heat exchanger pipes, departing from the tube sheet in the vertical direction, is carried out by appropriate installation of the wash head, with the flexible peak being moved along the guide system.

Based on this level of technology, the object of the present invention is to provide an improved method and an improved device for cleaning the inner zone of a heat exchanger, which, in particular, are well suited for cleaning heat exchangers with pipes running in a horizontal direction.

In relation to the device, this problem is solved by creating a device of the aforementioned type, which is intended for cleaning the inner zone of the heat exchanger and which has the features of claim 1.

Preferred embodiments of the invention are set forth in the dependent claims.

A device for cleaning the inner zone of the heat exchanger, in particular the steam generator of a nuclear power plant, with high-pressure water jets includes a manipulator installed in a vertical corridor between the bundles of heat exchanger tubes, and a lift connected to this manipulator. The manipulator has at least one swiveling nozzle installed with the possibility of rotation around the rotary axis, the orientation of which is consistent with the distance between the pipes in the tube bundle of the heat exchanger.

The elevator may, for example, be made in the form of a cable winch, which is located at the upper end of the corridor within the heat exchanger. The elevator, designed to adjust the vertical position of the manipulator, simultaneously serves to supply pneumatic, hydraulic pipelines and / or electrical cables.

When supplying a high-pressure water jet to the internal zone of the heat exchanger, it may be advisable to temporarily fix the manipulator inside the corridor using retractable locking means in order to effectively counteract the recoil forces that occur during cleaning.

The locking means, which extend in relation to the vertical corridor in the lateral, that is, horizontal direction, are driven mainly by pneumatic or electric means. Fixation with locking the manipulator is performed by an appropriate force action on the tube bundle, which limits the vertical corridor.

In a preferred exemplary embodiment, the locking means for connecting with the interlock include a pressure plate adapted to mate with several heat exchanger tubes. Thus, the force required to fix the manipulator can be distributed over several heat exchanger tubes.

Alternatively or additionally, the manipulator has at least one positioning grip for partially covering the horizontal passage of the heat exchanger tube. The dimensions of the positioning grip are chosen in accordance with the diameter of the heat exchanger pipe; this grip is adjacent to the pipe for temporary fixation of the manipulator. In a preferred exemplary embodiment, the positioning grip is located on one side of the manipulator opposite to the retractable pressure plate. Positioning grip serves for precise positioning of the manipulator relative to the tubes of the heat exchanger. In particular, it is provided for this that the spatial arrangement of the positioning grip on the manipulator relative to at least one rotary nozzle is coordinated with the distance between the tubes of the heat exchanger in such a way that the jet of water ejected by at least one nozzle hits the intermediate zone between adjacent tubes of the heat exchanger, when the positioning grip is adjacent to one of the tubes of the heat exchanger tube bundle. Due to this, water jets purposefully hit the intermediate zones to be cleaned, while avoiding the unnecessary formation of mist, which, for example, occurs during a frontal impact of the water jet on one of the heat exchanger tubes.

In another embodiment of the invention, it is provided that the pivot axis of said at least one nozzle is adjusted so that the water jet ejected by this nozzle can be rotated in a plane parallel to the heat exchanger tubes to clean the intermediate zones. Depending on the geometry of the spatial regular arrangement of the tubes of the heat exchanger, the intermediate zones to be cleaned are accessible from the vertical corridor at certain angles.

The targeted supply of high-pressure water jets to these zones and annular passages makes it possible to achieve a particularly efficient cleaning of the heat exchanger, since it is in these zones that an increased accumulation of deposits is observed.

In a possible exemplary embodiment of the invention, the rotary axis of said at least one nozzle is installed so that the water jet ejected by this nozzle can at least partially rotate with respect to the tube plate of the heat exchanger. To do this, the nozzle must be rotated around a rotary axis located perpendicular to the longitudinal axis of the manipulator, between the horizontal and vertical direction. With proper use of the manipulator, the longitudinal axis is aligned vertically, so that with horizontal orientation the nozzle is directed essentially parallel to the tubes of the heat exchanger, and with vertical orientation it is directed towards the tube sheet under the vertical corridor.

In the most preferred embodiment, there are several rotary nozzles. As a rule, the nozzles are installed with the possibility of rotation around rotary axes, which have different mutual orientation, in particular, pairwise different orientation. At the same time, the orientation of the rotary axes is coordinated with the geometry of the heat exchanger or steam generator so that the nozzles direct their water jets into the annular passages and intermediate zones when the manipulator is fixed in the vertical corridor in the given positions.

In another embodiment of the invention, several nozzles may have the same orientation. Nozzles can be installed on the side of the manipulator or on opposite sides of the manipulator, making it possible to simultaneously clean the corresponding adjacent tube bundle.

According to the common configuration of steam generators, intermediate zones and annular passages are located at an angle of about 30 °, 90 ° and 150 ° with respect to the vertical. Therefore, it turned out to be advantageous to appropriately set the position of the pivot axes relative to the longitudinal axis of the manipulator, due to which the water jets ejected by the nozzles can optionally be directed in the plane along the tube sheets. The longitudinal axis of the manipulator for cleaning the heat exchanger is directed along the vertical corridor, so that the rotary axes of the three nozzles should preferably be located at an angle of 120 °, 0 ° and 30 ° with respect to the longitudinal axis.

It should be noted that the direction of the rotary axes of the nozzles is due to the geometry of the tubes of the heat exchanger in the steam generator. Thus, the direction of the rotary axes must be coordinated with the constructive shape of the steam generator so that the nozzles throw water jets into the intermediate zones and the annular passages when the manipulator is fixed at the specified positions within the vertical corridor.

In a preferred exemplary embodiment, at least two nozzles with a horizontal orientation are provided, the rotary axes of which extend vertically or the longitudinal axis of the manipulator. Both nozzles are installed at a distance from each other that corresponds to the diameter of the pipes in the tube bundle of the heat exchanger. With this arrangement, the nozzles can be cleaned at the same time two annular passage without the need to rearrange the manipulator.

It should be noted that the manipulator is placed mainly in those places within the vertical corridor, of which at least one nozzle throws a water jet into the intermediate zone between two adjacent tubes of the heat exchanger. Therefore, proposed step-by-step positioning of the manipulator, consistent with the distance between the pipes. In a possible exemplary embodiment, the step size is set using a path sensor, which is in active communication with the elevator.

In another exemplary embodiment, the manipulator includes a stepping mechanism with at least one retractable clamping lever that is adapted to grip adjacent heat exchanger tubes.

The clamping lever can be extended both in the direction of the vertical corridor and in the horizontal direction, due to which the manipulator can move the manipulator along the vertical corridor with the help of the stepping mechanism. In this case, the positioning of the manipulator is carried out largely by self-installation, so that in this example of execution the elevator primarily solves the problem of additional security.

In the preferred exemplary embodiment, the stepping mechanism comprises an air cylinder for positioning the extendable clamping lever. For fixing the manipulator, the clamping lever at least partially covers the adjacent heat exchanger pipe, which runs horizontally. The position of the clamping lever with respect to the vertical and horizontal direction can be changed using a stepping mechanism, so that the manipulator can "step" along the vertical corridor from one heat exchanger pipe to another.

To monitor the cleaning process, the manipulator may, for example, have at least one rotating chamber, which can be directed to the heat exchanger area to be cleaned. Alternatively or additionally, there is a camera mounted on the upper end of the vertical corridor.

It is especially recommended to provide a suction device with a suction pipe for sucking the suspension containing delaminated particles. In particular, the suction line can be installed in various places inside the heat exchanger or steam generator to transport the exfoliated particles to the outside.

The suction device can be connected to a filtering device for filtering the sucked suspension. The filtered water can be used again in the process to ensure the preservation of natural resources.

It is especially recommended to provide means for remote control of the device, in particular, fixing means, direction of at least one nozzle and / or at least one camera, a lift, a stepping mechanism and / or a suction device. Thus, especially when used in nuclear power plants, it is possible to minimize the radiation doses received by service personnel during operation.

In relation to the method, the problem is solved by creating a method for cleaning the inner zone of the heat exchanger of the above-mentioned type, which has the features of clause 17 of the claims.

A method is proposed for cleaning a heat exchanger, in particular, a steam generator of a nuclear power plant with high-pressure water jets using the above-described device in the corresponding embodiments, to which reference is made.

A manipulator connected to the elevator is inserted into a vertical corridor inside the heat exchanger. The vertical corridor on the sides is bounded by bundles of pipes containing heat exchanger pipes running horizontally. To clean the inner zone of the heat exchanger from at least one nozzle located on the manipulator, produce a water jet, rotated with respect to the cleaned area.

When cleaning the inner zone of the heat exchanger, the manipulator is temporarily fixed with a lock inside the vertical corridor at a given position. Temporary fixation of the manipulator ensures that water jets are deliberately fed into the cleaned intermediate zones and annular passages, even if high pressures are used (for example, 100 bar).

Further details of possible embodiments of the present invention are explained with reference to the drawings:

FIG. 1. The basic design of the device for cleaning the steam generator in a schematic sketch.

FIG. 2. The manipulator according to the first exemplary embodiment of the invention.

FIG. 3. A manipulator with a step mechanism according to a second exemplary embodiment of the invention.

Corresponding parts in all drawings have the same designation.

FIG. 1 schematically illustrates a device 1 for cleaning the second circuit of a steam generator 2. A sectional view of a steam generator 2 is shown containing heat exchanger tubes 3 which extend in a horizontal direction.

The device 1 includes a lift 4 connected to the manipulator 5. The lift 4 is installed inside the steam generator 2 through the service opening of the vertical corridor 6. Vertical corridor 6 passes between the bundles of pipes 3 of the heat exchanger. The elevator 4 serves to fix and / or position the manipulator 5 within the vertical corridor 6. At the same time, the elevator 4 serves to supply electrical cables, pneumatic and / or hydraulic pipelines to the manipulator 5. Further, the elevator 4 is equipped with a path sensor 7, which works as a displacement sensor and provides accurate positioning of the manipulator 5 within the vertical corridor 6.

The manipulator 5 has at least one rotary nozzle 8, which can be aligned in the direction of the intermediate zones between adjacent pipes 3 of the heat exchanger. To clean the intermediate zones or annular passages, the nozzle 8 can be rotated around a rotary axis so that the high-pressure water jet coming out of the nozzle 8 passes in a plane parallel to the pipes 3 of the heat exchanger.

The suction device 9 contains a suction pipe 10, which is typically installed in the zone of the tube of the steam generator 2 for suction of exfoliated particles P. In FIG. 1 shows, as an example, an arrangement in which the suction pipe 10 runs along the side. Of course, other layout options are also possible, which differ from those indicated on the drawing. For example, the suction pipe 10 may also pass down through the vertical corridor 6.

Pumps 11 and 12 are connected to the suction line 10, which transport the suspension containing the exfoliated particles to tank 13. Another pump 14 delivers contaminated water from tank 13 to intermediate storage 16 through a filtering device 15 connected between them. Pumps 12 and 14 form a filter circulation circuit which sufficiently purifies the water entering the manipulator 5 through the pipe 17 from particles R.

Further, to control the cleaning process, a rotating camera 18 is installed at the upper end of the vertical corridor 6, the range of observation of which, if necessary, can be adjusted to specific requirements.

The device 1 can be completely controlled remotely by the control device 19. In other words, all the control parameters, in particular, the parameters of the electric, pneumatic and / or hydraulic subsystems, can be set using the control device 19. For example, the angle of rotation can be appropriately set and / or the speed of rotation of the nozzle 8, the pressure of water and / or the duration of exposure to water jets.

To do this, device 19 has a user interface 20, through which actual information, such as photos taken by camera 18, can also be output. For this purpose, user interface 20 has all the necessary output means by means of which appropriate optical or acoustic information can be output.

According to the method for cleaning the inner zone of the steam generator, the lift 4 is first positioned at the upper end of the vertical corridor 6, and the manipulator 5 is placed in the vertical corridor 6. Then the suction pipe 10 is properly positioned, as a result of which particles 2 that have accumulated in the lower zone of the steam generator can be discharged. This modular design of the device 1 provides quick installation and disassembly. Cleaning the intermediate zones between the heat exchanger pipes 3 is performed successively with a “slot behind the slit”, while prior to supplying high-pressure water jets the manipulator 5 is temporarily fixed with a lock in the vertical corridor 6. The exfoliated deposits and particles P are sucked off through the suction pipe 10 and drained into the tank 13. The pump 14 pumps the suspension containing particles P in the direction of the intermediate accumulator 16. The pre-included filter device 15 separates the particles P from the transported suspension, due to which the filter bath water can be supplied to the manipulator 5 for further purification of the inner zone of the steam generator 2. Due to limited access to the cleaning process of cleaning the inner region entirely remotely controlled, wherein the course of purification process is controlled on the basis of images taken by the camera.

FIG. 2 shows the manipulator 5 according to a possible exemplary embodiment of the invention. The manipulator 5 is located in the vertical corridor 6 in such a way that the longitudinal axis L of the manipulator 5 runs parallel to the vertical V. For fixing with blocking, the manipulator 5 has a retractable pressure plate 21 and a positioning gripper 22 opposite it, which encloses one of the heat exchanger tubes 3. Positioning grip 22 is made in accordance with the configuration of the pipes, which ensures its self-installation, so that the positioning of the manipulator 5 relative to the pipes 3 of the heat exchanger is performed in certain positions.

The manipulator 5 has several nozzles 8.1, 8.2, 8.3, 8.4, the spatial location of which relative to the positioning grip 22 is consistent with the location of the intermediate zones to be cleaned and the annular passages. Nozzles 8.1, 8.2, 8.3, 8.4, respectively, are aligned in the direction of the annular passages, which are at an angle of 30 °, 90 ° and 150 ° relative to the vertical V. The nozzles 8.1, 8.2, 8.3, 8.4 are rotatable. In particular, the rotary nozzle 8.1 is installed in such a way that the water jet emanating from it can rotate in the E1 plane, which runs parallel to the heat exchanger tubes 3 and at an angle of about 30 ° with respect to the vertical V. In other words, the nozzle 8.1 has a rotary axis S1, which runs at an angle of 120 ° relative to the vertical V. The nozzle 8.4 emits a water jet along the E4 plane, which is located at an angle of 150 ° relative to the vertical V. In accordance with this, the nozzle 8.4 can rotate around the rotary axis S4, which passes od angle of 60 ° relative to the vertical V.

Nozzles 8.2 and 8.3 are used to clean the annular passageways that pass horizontally. In accordance with this nozzle 8.2 and 8.3 are separated from each other at a distance, which essentially corresponds to the diameter of the pipes 3 of the heat exchanger. The water jets ejected from the nozzles 8.2 and 8.3 can rotate relative to the horizontal planes S2 and S3, in accordance with this, the rotary axes S2 and S3 connected to the nozzles 8.2 and 8.3 run parallel to the vertical V and the longitudinal axis L of the manipulator 5.

Nozzles 8.1, 8.2, 8.3, 8.4 are respectively placed on one side of the manipulator 5. Cleaning of intermediate zones and annular passages is performed on one side over the entire segment of the tube bundle by means of a suitable rotational motion of nozzles 8.1, 8.2, 8.3, 8.4.

Further, shown in FIG. 2, the manipulator 5 has another chamber 23, which can also be rotated and, thus, if necessary, can be directed towards the zone to be cleaned.

FIG. 3 shows a manipulator according to another exemplary embodiment of the invention. Regarding the location of nozzles 8.1, 8.2, 8.3, 8.4, the exemplary embodiment shown in FIG. 3 does not differ from the embodiment shown in FIG. 2, so that the link to the corresponding description is quite possible here.

Manipulator 5, made as shown in FIG. 3, contains a stepping mechanism with a pneumatic cylinder 24 and clamping levers 25 and 26. Clamping levers 26 can be extended both in the direction of the longitudinal axis L and in the direction perpendicular to this axis. In contrast to this, the clamping arms 25 opposite them are fixed, so that the distance from the nozzles 8.1, 8.2, 8.3, 8.4 installed there can definitely be set before the entrance to the slot between the pipes. Alternative options are also possible for this, in which the nozzles 8.1, 8.2, 8.3, 8.4 are placed only on one side, that is, for example, only on the right side of the vertical corridor 6 and the manipulator 5.

The clamping levers 25 and 26 located on the opposite side can also be extended both vertically and horizontally. In particular, pneumatic and / or electric actuators are provided for this.

The ends of the clamping arms 25 and 26, designed to fit to the pipes 3 of the heat exchanger, are made in the form of grips and cover the pipes 3 of the heat exchanger for temporarily fixing the manipulator 5 by analogy with the procedure described above for the positioning grip 22 in the first exemplary embodiment. The step of the stepping mechanism along the vertical V corresponds to the distance between the pipes. The adjustment tool 27 can be adjusted by means of the adjusting mechanism 28 so that the pitch of the stepping mechanism, especially when the distance between the pipes in two bundles of pipes bounding the vertical corridor is different, corresponds to the correct distance between the pipes 3 of the heat exchanger. Similarly, the displacement of pipes along the vertical V can also be compensated.

Thanks to the stepping mechanism, the remote-controlled manipulator 5 can be positioned in various places within the vertical corridor 6. In this case, the clamping levers 25 and 26 moving in both directions and installed independently of each other serve for fixing and compensating for the shift of the tube bundle and can be adjusted accordingly. vertical and horizontal direction.

In addition to the one shown in FIG. The 3 variants of positioning and tensioning the manipulator 5 in a vertical corridor 6 with a double-sided arrangement of nozzles 8.1, 8.2, 8.3, 8.4 can also be chosen with a single-sided arrangement of nozzles, as shown by way of example in FIG. 2

The invention has been described above with reference to preferred embodiments. It should, however, be noted that the invention is by no means limited to the examples shown; moreover, on the basis of the above description, a competent specialist can create new variants, while remaining within the essence of this invention.

List of Legend

one Device 2 Steam generator 3 Heat Exchanger Tubes four Lift five Manipulator 6 Vertical corridor 7 Track sensor eight Nozzle 8.1 Nozzle 8.2 Nozzle 8.3 Nozzle 8.4 Nozzle 9 Suction device ten Suction line eleven Pump 12 Pump 13 Storage tank 14 Pump 15 Filtering device sixteen Intermediate drive 17 Supply pipe 18 Camera

nineteen Control device 20 User interface 21 Pressure plate 22 Positioning grip 23 Camera 24 Pneumatic cylinder 25 Clamping lever 26 Clamping lever 27 Adjustment tool 28 Adjustment mechanism R Particles V Vertical L Longitudinal axis E1 Plane E2 Plane E3 Plane E4 Plane S1 Pivot axis S2 Pivot axis S3 Pivot axis S4 Pivot axis

Claims (18)

1. Device (1) for cleaning the inner zone of the heat exchanger, in particular the steam generator (2) of a nuclear power plant, with high-pressure water jets, including a manipulator (5) installed in a vertical corridor (6) passing between the bundles of heat exchanger tubes, and a lift (4 ), connected with this manipulator (5), and the manipulator (5) has at least one rotary nozzle (8.1, 8.2, 8.3, 8.4) installed rotatably around the rotary axis (S1, S2, S3, S4), orientation which is matched with the distance between the pipes in the pipe bundle b (3) heat exchanger. 2. Device (1) according to claim 1, in which the manipulator (5) within the vertical corridor (6) is installed with the possibility of temporary fixation with blocking with the help of sliding locking means. 3. Device (1) according to claim 2, characterized in that the fixing means are actuated by pneumatic or electric means. 4. Device (1) according to claim 2 or 3, in which the locking means for locking with a lock include a pressure plate (21) adapted to interface with several heat exchanger tubes (3). 5. Device (1) according to claim 1, in which the manipulator (5) includes at least one positioning grip (22) to cover at least a partial, horizontally passing pipe (3) of the heat exchanger. 6. Device (1) according to claim 1, in which the pivot axis (S1, S2, S3, S4) of at least one nozzle (8.1, 8.2, 8.3, 8.4) is adjusted so that the water jet pushed out at least from one nozzle (8.1, 8.2, 8.3, 8.4), could be rotated parallel to the tubes (3) of the heat exchanger to clean the intermediate zones located between the tubes (3) of the heat exchanger in the plane (E1, E2, E3, E4). 7. Device (1) according to claim 1, in which the rotary axis of at least one nozzle (8.1, 8.2, 8.3, 8.4) is aligned so that ejected from at least one nozzle (8.1, 8.2, 8.3, 8.4) the water jet could at least partially rotate with respect to the tube plate of the heat exchanger. 8. Device (1) according to claim 1, in which there are several rotary nozzles (8.1, 8.2, 8.3, 8.4) installed rotatably around the respective rotary axes (S1, S2, S3, S4), the orientation of which is different. 9. Device (1) according to claim 1, in which at least three nozzles (8, 8.1, 8.2, 8.3, 8.4) are provided, the rotary axes of which (S1, S2, S3, S4) run at an angle of 0 °, 60 ° and 120 ° with respect to the longitudinal axis (L) of the manipulator (5). 10. Device (1) according to claim 1, in which, using the lift, which is in active communication with the track sensor (7), step-by-step positioning of the manipulator is performed, coordinated with the distance between the pipes. 11. Device (1) according to claim 1, in which step-by-step positioning, consistent with the distance between the pipes, is carried out using the stepping mechanism of the manipulator (5). 12. Device (1) according to claim 11, in which the stepping mechanism comprises at least one pneumatic cylinder (24) for positioning the extendable clamping lever (25) of the manipulator (25) configured to partially extend the horizontal heat exchanger tube. 13. The fixture (1) according to claim 1, wherein for monitoring the cleaning process, the manipulator (5) further comprises at least one turning chamber (23), which is directed to one of the heat exchanger cleaned zones. 14. Device (1) according to claim 1, in which a suction device (9) is provided with a suction pipe (10) for sucking a suspension containing detached particles (P). 15. Device (1) according to claim 14, in which the suction device (9) is connected to a filtering device (15) for filtering the aspirated suspension. 16. Adaptation (1) according to any one of paragraphs. 1, 2, 11, 13 and 14, in which means are provided for remote control of the device (1), in particular, remote control of the fixing means, the direction of at least one nozzle (8, 8.1, 8.2, 8.3, 8.4) and / or at least one camera (18, 23), a lift (4), a step mechanism and / or a suction device (9). 17. The method of cleaning the heat exchanger, in particular, the steam generator (2) of a nuclear power plant, high-pressure water jets using device (1) according to any one of the preceding paragraphs, according to which the manipulator (5) connected to the elevator (4) is introduced into the vertical corridor ( 6) inside the heat exchanger, on the sides limited by tube bundles, which respectively contain horizontally passing tubes (3) of the heat exchanger, and at least one nozzle (8, 8.1, 8.2, 8.3, 8.4), which can be rotated around a rotary the axes (S1, S2, S3, S4), the orientation of which is matched with the distance between the pipes in the tube bundle (3) of the heat exchanger, release a water jet that is rotated with respect to the zone being cleaned. 18. A method according to claim 17, according to which for cleaning the heat exchanger the manipulator (5) is temporarily fixed with a lock inside the vertical corridor (6) in the given positions.

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