Manipulator for swing cover of switch steam generator access hole and related method

Abstract

A manipulator (1) for opening and closing a swing cover (2) of an access opening (3) of a steam generator (4) comprises a trolley assembly (5) and a winch assembly (6) which is detachably mounted on the trolley assembly (5) and comprises a winch (7) provided with a pair of cable lines (8). The winch assembly (6) is further provided with a pair of hooks (9) for suspending the winch assembly (6) on a shaft (2a) of the swing cover (2) and with two threaded anchors (10) each attached at one end of one of the cable lines (8) for passing through a first through hole (2b) of the swing cover (2) and for screwing into an internal thread (11) of a second hole (12) in a base plate (13) of the steam generator (4) to provide a support point for the associated cable line (8), the winch (7) being adapted to wind up and out the cable lines (8) in order to rotate the swing cover (2) between a closed cover position and an open cover position.

Description

Technical Field

[0001] This invention relates to an actuator for opening and closing a cover for a manhole in a steam generator used in a nuclear power plant. The invention also relates to related methods for opening and closing such a cover. Background Technology

[0002] In nuclear power plants using pressurized water reactors or PWR technology, heat is provided by an intermediate heat transfer fluid that transfers heat from the reactor core to the steam generator.

[0003] It is necessary to enter the interior of this steam generator periodically, for example, to perform inspection and maintenance operations.

[0004] Access can be made by opening the access panel.

[0005] Outside of inspection and maintenance operations, each access port is sealed by a cover that ensures the watertightness of the steam generator.

[0006] Typically, these covers are heavy and difficult for maintenance personnel to manipulate while opening and closing the access panel.

[0007] In addition, it is usually necessary to minimize downtime.

[0008] However, in the existing technology, the positioning of the cover relative to the steam generator is not very precise, and maintenance personnel must spend time to obtain the correct position.

[0009] In addition, it is usually necessary to keep the open cover as close as possible to the steam generator.

[0010] Therefore, there is a need for a solution for opening and closing the access port cover of a steam generator that meets the above requirements and ensures quick and precise operation of the cover during opening and closing of the access port. Summary of the Invention

[0011] This invention relates to an actuator for opening and closing a swing cover for an access port of a steam generator. The actuator includes a trolley assembly and a winch assembly, the winch assembly being detachably mounted to the trolley assembly and including a winch with a pair of cables. The winch assembly is for engaging with the swing cover and is provided with a pair of hooks for suspending the winch assembly on the axis of the swing cover, and has two threaded anchors, each anchor attached to the end of one of the cables for passing through a first through-hole in the swing cover and threadedly connected to the internal threads of a second hole on the steam generator base plate, thereby providing a support point for the associated cable. The winch is adapted to wind up and unwind the cable to rotate the swing cover between a closed position with the first through-hole aligned with the second hole and an open position with the swing cover at a neutral suspension point.

[0012] The controller allows for the safe and controlled opening and closing of access cover, thereby minimizing downtime.

[0013] Preferably, the winch assembly is further provided with a positioning device for cooperating with a corresponding receiving device disposed on the swing cover to ensure the correct position of the winch assembly relative to the swing cover.

[0014] For example, the positioning device includes a pair of positioning cones, and the receiving device includes a pair of second through holes disposed between the shaft and the first through hole, each positioning cone being designed to be inserted into a second through hole.

[0015] In some embodiments, each hook includes a body and a rotatably mounted jaw that can move between an open position and a closed position. When the jaw is in the closed position, the body and the jaw together define an elliptical lateral opening.

[0016] Preferably, the manipulator also includes a cable guide associated with each wire.

[0017] For example, a cable guide device includes a pair of guide wheels associated with each of the cables and disposed on the frame of the winch assembly.

[0018] In one set of embodiments, the cable guiding device includes a cover cable guide and a substrate cable guide, which are respectively detachably mounted on the cover and the substrate.

[0019] Advantageously, the trolley assembly is provided with a lifting device suitable for vertically moving the winch assembly.

[0020] According to another aspect of the present invention, a method is provided for opening and closing a swing cover using the actuator as defined above. The method includes the following steps:

[0021] -Approach the cover shaft with the manipulator.

[0022] - Suspend the winch assembly on the cover shaft.

[0023] - Separate the winch assembly from the handcart assembly.

[0024] - Pull the line through the cover and thread the anchor to the substrate.

[0025] - Wind up the cable to lift the winch assembly onto the cover until the winch assembly engages the cover.

[0026] -Remove the cover completely from the substrate.

[0027] - Unwind the line to lower the cover until a neutral suspension point corresponding to the open cover position is reached.

[0028] - Unwind the cable until fully slack and remove the anchors from the substrate, then wind the cable onto a winch.

[0029] Remove the winch assembly together with the trolley assembly.

[0030] According to another aspect of the present invention, a method is provided for closing an open swing cover using the actuator as defined above. The method includes the following steps:

[0031] -Approach the cover with the manipulator.

[0032] - Engage the cover with the winch assembly.

[0033] - Suspend the winch assembly on the cover shaft.

[0034] - Separate the winch assembly from the handcart assembly.

[0035] - Pull the line through the cover and thread the anchor to the substrate.

[0036] - Roll up the line to raise the cover to the closed position.

[0037] - In the closed position, briefly tighten the cover to the substrate.

[0038] - Unwind the cable until it is fully slack to lower the winch assembly from the cover.

[0039] Remove the anchor from the substrate and retrieve the cable from the winch.

[0040] - Remove the winch assembly along with the trolley assembly, and

[0041] - Long-term fastening of the cover to the substrate. Attached Figure Description

[0042] The invention and its advantages will be better understood by studying the detailed description of the specific embodiments given by way of non-limiting examples and illustrated in the accompanying drawings, in which:

[0043] - Figure 1 This is a perspective view of an example manipulator according to the present invention.

[0044] - Figure 2 yes Figure 1 Side view of the manipulator.

[0045] - Figure 3 yes Figure 1 Detailed side view of the winch assembly of the operator when the cover is engaged.

[0046] - Figure 4 It is in a low position. Figure 1 Side view of the trolley assembly of the manipulator.

[0047] - Figure 5 It is in a high position Figure 4 Handcart components,

[0048] - Figure 6 yes Figure 1 A perspective view of the cover cable guide of the controller when it is clamped onto the cover.

[0049] - Figure 7 yes Figure 1 A perspective view of the baseboard cable guide of the controller when it is clamped onto the baseboard.

[0050] - Figure 8 It is used for utilization Figure 1 A flowchart of the method for opening and closing the swing cover using a manipulator.

[0051] - Figures 9 to 12 and Figures 14 to 17 schematically shown Figure 8 Some steps of the method;

[0052] - Figure 13 yes Figures 9 to 12 and Figures 14 to 17 Front view of the cover

[0053] - Figure 18 It is Figure 1 A flowchart of the method for closing the open swing cover using a manipulator, and

[0054] - Figures 19 to 24 schematically shown Figure 18 Some steps of the method. Detailed Implementation

[0055] Figure 1 and Figure 2 The manipulator 1 shown is adapted to open and close the cover 2 of the access port 3 of the steam generator 4 for a nuclear power plant.

[0056] The cover 2 is configured to rotate about the shaft 2a between a closed position and an open position. The shaft 2a is fixed to the steam generator 4 and is properly coplanar with the cover 2.

[0057] The manipulator 1 includes a handcart assembly 5 and a winch assembly 6.

[0058] The winch assembly 6 is detachably mounted to the trolley assembly 5, for example, by a pair of removable ball-locking pins 6a that allow the winch assembly to rotate freely. The winch assembly 6 includes a winch 7 with a pair of cables 8. The winch assembly 6 is designed to engage the swing cover 2 and is also provided with a pair of hooks 9 designed to suspend the winch assembly 6 on the shaft 2a. The winch assembly 6 is provided with two threaded anchors 10, each anchor 10 being attached to one end of one of the cables 8 for passing through a first through hole 2b of the swing cover 2 and fastening to the internal thread 11 of a second hole 12 provided on the base plate 13 of the steam generator 4, thereby providing a support point for the associated cable 8.

[0059] For example, tightening and loosening of the anchor 10 is achieved using a turning tool (not shown) having a head and an elongated body. The head is provided with at least two fingers that mate with a plurality of associated holes provided on each anchor 10. Once the fingers are inserted into the associated holes, this allows for joint rotation of the turning tool and the anchor 10. The elongated body has a central portion and a tail.

[0060] The tightening tool is provided with a groove along its entire length to receive the cable 8 associated with the anchor 10 within the tightening tool. The length of the tightening tool is such that when the finger is inserted into the relevant hole of the anchor 10, the elongated body extends through the width of the cover 2, with the tail protruding beyond the cover 2.

[0061] The winch 7 is adapted to wind up and unwind the cable 8 so that the swing cover 2 rotates about the axis 2a between a closed cover position and an open cover position. In the closed cover position, the first through hole 2b is aligned with the second hole 12. In the open cover position, the swing cover 2 is at the neutral hanging point.

[0062] The winch assembly 6 is also equipped with a positioning device 14. For example, in Figure 3 Specifically visible, the positioning device 14 cooperates with the associated receiving device 15 disposed on the swing cover 2 to ensure the correct position of the winch assembly 6 relative to the swing cover 2.

[0063] It should be noted that similar or identical elements are identified by the same reference numerals in different accompanying drawings.

[0064] like Figure 3 As shown in the example, the positioning device 14 may include a pair of positioning cones 16 having a base plate 16a. The receiving device 15 may include a pair of second through holes 17 disposed between the shaft 2a and the first through hole 2b. Each positioning cone 16 is inserted into one of the second through holes 17 and contacts the hole 17a of the corresponding second through hole 17 when the winch assembly 6 engages with the cover 2. When the positioning cone 16 is fully engaged in the second through hole 17, the base plate 16a contacts the outer surface 2c of the cover 2.

[0065] like Figure 2 As shown more clearly in the diagram, each hook 9 includes a body 9a and a rotatably mounted jaw 9b, which is movable between an open position and a closed position. When the jaw 9b is in the closed position, the body 9a and the jaw 9b together define an elliptical transverse opening 9c. The elliptical transverse opening 9c facilitates the correct positioning of the winch assembly 6 relative to the cover 2 because when the winch assembly 6 engages the cover 2, the elliptical transverse opening 9c allows for translation and rotation relative to the axis 2a. Figure 3 When the outer surface 16b of each positioning cone 16 abuts against the corresponding hole 17a, this feature allows the winch assembly 6 to be pushed into the correct position. Furthermore, when the base plate 16a contacts the outer surface 2c of the cover 2, the elliptical lateral opening 9c allows the cover 2 to slide upwards, thereby allowing the cover 2 to be properly aligned relative to the base plate 13 of the steam generator 4. Then, before removing the winch assembly 6, two short fasteners can be easily tightened to hold the cover 2 in place. The cover 2 can be slid upwards using a lever or a pushing device (e.g., a hydraulic head).

[0066] The trolley assembly 5 is provided with a lifting device 18, which is adapted to lift a pair of arms 19 respectively in Figure 4 and Figure 5 The winch assembly 6 is vertically displaced between the low and high positions shown. Each arm 19 defines a lifting point 19a, at which the winch assembly 6 is detachably mounted. The ability to move the arms 19 vertically allows the manipulator 1 to easily lift the winch assembly 6 to a high position where it can hook the shaft 2a, and to lower the winch assembly 6 as needed for suspension or retraction. For example, the lifting device 18 may include a winch lifter 20 associated with a series of pulleys 21. Figure 4 ).

[0067] The manipulator 1 also includes a cable guide 22 associated with each cable 8. The cable guide 22 controls the position of the cable 8 and protects the structural integrity of the cable 8 and nearby components (such as the cover 2 and the substrate 13) from friction or unwanted contact.

[0068] As in Figure 3 As can be specifically seen in the example shown, the cable guide device 22 includes a pair of jockey wheels 23, which are associated with each of the cables 8 and are mounted on the frame 24 of the winch assembly 6.

[0069] For example, the cable guide device 22 includes a cover cable guide 25 and a substrate cable guide 26, which are detachably mounted on the cover 2 and the substrate 13, respectively. The cover cable guide 25 prevents the cable 8 from contacting the cover 2 during the entire movement of the cover 2.

[0070] like Figure 6As shown in the example, the cable guide 25 includes a main support 25a, two arms 25a', a pair of main rollers 25b, and a pair of front rollers 25c. The main support 25a extends, and the two arms 25a' extend between the main rollers 25b and the front rollers 25c. The front rollers 25c and the main rollers 25b are mounted on the free ends of the arms 25a' and the main support 25a, respectively, for example, on needle roller bearings.

[0071] The cable guide 25a also includes an outer guide plate 25d extending between the main roller 25b and the front roller 25c. The main roller 25b and the front roller 25c are respectively sandwiched between the outer guide plate 25d and the main bracket 25a and the arm 25a'.

[0072] The cable guide 25 also includes a pair of partitions 25e sandwiched between the outer guide plate 25d, the main support 25a, and the arm 25a'. Each partition 25e is disposed between the front roller 25c and the main roller 25b. Preferably, each partition 25e is made of a material with a lower hardness than the cable 8 to protect the durability of the cable 8. For example, the partition 25e may be made of nylon.

[0073] The main support 25a and arm 25a' are assembled together with the partition 25e and the outer guide plate 25d, for example with nuts and bolts.

[0074] The cover cable guide 25 also includes an eccentric clamp 25f, which allows clamping onto the cover 2. Just before clamping, the front roller 25c, the outer guide plate 25d, and the partition 25e are inserted into the first through hole 2b, and then the eccentric clamp 25f is used to clamp the cover cable guide 25 onto the cover 2.

[0075] like Figure 7 As shown in the example, the substrate cable guide 26 includes a main support 26a, two arms 26a', a pair of cable guide plates 26b, and an outer guide plate 26c. The cable guide plates 26b are sandwiched between the outer guide plate 26c and the main support 26a and the arms 26a'. The main support 26a and the two arms 26a' are assembled with the cable plates 26b and the outer guide plate 26c, for example, using nuts and bolts. The substrate cable guide 26 specifically protects the substrate 13 by preventing any unwanted contact between the cable 8 and the substrate 13, for example, when the cover 2 is lowered to the open position.

[0076] Figure 8 This is a flowchart illustrating a method 30 for opening and closing the swing cover 2 using the aforementioned manipulator 1.

[0077] It is important to note that before opening and closing the swing cover 2, all long-term fasteners from cover 2 to the base plate 13 are replaced with short-term fasteners. This means that all long-term fasteners (typically studs) of the cover located within the coverage area of ​​the winch assembly 6 or the path of the cable 8 are removed, and cover 2 is temporarily held in place by means of short-term fasteners, preferably using, for example... Figure 13 The two centering tools shown are 2d. The terms "short-term" and "long-term" are intended to distinguish between temporary tightening of the cover used during maintenance and final tightening used during steam generator operation. Temporary tightening can be achieved quickly without the use of special tensioning materials; it allows the component to be relatively fixed, but does not guarantee stability over time. In contrast, a final tightening, which is more robust than the previous tightening, can withstand the normal stresses that the cover is exposed to during steam generator operation.

[0078] In step 31, the manipulator 1 approaches the cover shaft 2a, as... Figure 9 As shown. Step 31 includes using the lifting device 18 to lift the winch assembly 6 to a high position.

[0079] In step 32, the winch assembly 6 is suspended on the cover shaft 2a using hook 9. Figure 10 Step 32 includes lowering the winch assembly 6 to its free suspension point. Figure 11 ).

[0080] At step 33, the winch assembly 6 is separated from the trolley assembly 5. Once the winch assembly 6 is disassembled, the trolley assembly 5 can be pulled back as follows. Figure 12 The detachment area is shown.

[0081] While the cover 2 is briefly secured in place, the cable 8 is pulled through the first through hole 2b of the cover 2, and the anchor 10 is screwed into the internal thread 11 of the second hole 12 of the substrate 13 using a screwdriver (step 34). Preferably, the cable 8 is guided through the cable guide device 22, for example, by rolling on the guide wheel 23.

[0082] Preferably, in step 34 or immediately following step 34, the cover cable guide 25 is inserted into the first through hole 2b of the cover 2, so that the cable 8 is guided by rollers 25c and 25d. Then, the cover cable guide 25 is clamped onto the cover 2. Figure 14 ).

[0083] In step 35, the winch assembly 6 is raised to the cover 2 by winding the cable 8 upwards and tensioning the cable 8 until the winch assembly 6 engages the cover 2, as shown. Figure 15 As shown. The cable 8 is tensioned using the winch 7. For example, the winch assembly 6 engages the cover when the positioning cone 16 is fully inserted into the second through hole 17 and the base plate 16a contacts the outer surface 2c of the cover 2.

[0084] In step 36, the cover 2 is completely loosened from the substrate 13 by removing the short fasteners (here, the two centering tools 2d).

[0085] After cover 2 is fully released, cable 8 is wound out to lower cover 2 until it reaches... Figure 16 The neutral suspension point shown corresponds to the open cover position (step 37). It should be noted that in step 37, the substrate cable guide 26 is mounted on the substrate 13 to prevent any unwanted contact between the cable 8 and the substrate 13. For ease of installation, the substrate cable guide 26 is installed in a mounting position where the cable 8 is substantially parallel to the bore of hole 2b, and where sufficient space is left between the cover 2 and the substrate 13 to allow for proper insertion of the substrate cable guide 26. This mounting position is achieved, for example, when the cover 2 forms an angle of approximately 15° relative to the substrate 13.

[0086] After cover 2 reaches the neutral suspension point, cable 8 is wound out until fully slack. Figure 17 Then remove cable clips 25 and 26 from cover 2 and base plate 13. Then, use a tightening tool to remove anchor 10 from base plate 13 and wind cable 8 onto winch 7 until it is fully wound up (step 38).

[0087] When cable 8 is in the fully wound position on winch 7, winch assembly 6 is removed together with trolley assembly 5 (step 39).

[0088] Figure 18 This is a flowchart illustrating a method 50 for closing an open swing cover 2 using the aforementioned manipulator 1.

[0089] In step 51, the manipulator 1 approaches the opened cover 2. Step 51 includes using the lifting device 18 to raise the winch assembly 6 to a high position. Figure 19 ).

[0090] At step 52, the winch assembly 6 engages the cover 2. For example, the winch assembly 6 engages the cover when the positioning cone 16 is fully inserted into the second through hole 17 and the substrate 16a contacts the outer surface 2c of the cover 2.

[0091] In step 53, the winch assembly 6 is suspended on the cover shaft 2a, as follows: Figure 20 As shown.

[0092] At step 54, the winch assembly 6 is detached from the trolley assembly 5. Once the winch assembly 6 is detached, the trolley assembly 5 can be pulled back as follows. Figure 21 The unobstructed area is shown.

[0093] In step 55, the cable 8 is pulled through the first through hole 2b of the cover 2, and the anchor 10 is screwed into the internal thread 11 of the second hole 12 of the substrate 13 using a tightening tool. In step 55, the cable 8 is guided through the cable guide device 22, for example, by rolling it on the guide wheel 23. At step 55, the cover cable guide 25 and the substrate cable guide 26 are respectively mounted on the cover 2 and the substrate 13. Figure 22 ).

[0094] In step 56, cable 8 is tensioned by coiling to lift cover 2. Figure 23 The closed cover position is shown. To allow cover 2 to reach the closed cover position, the substrate cable guide 26 is removed once there is no risk of unwanted contact between the cable 8 and the substrate 13. For example, the substrate cable guide 26 is removed when cover 2 forms an angle of approximately 15° with the substrate 13. In this position, the cable 8 is substantially parallel to the hole 2b, and the distance between cover 2 and substrate 13 leaves sufficient space for proper removal of the substrate cable guide 26.

[0095] In step 57, using a short-term fastening tool, preferably such as... Figure 13 The two centering tools 2d shown temporarily fasten the cover 2 to the substrate 13.

[0096] At step 58, the cable 8 is wound out to full slack using the winch 7, so that the winch assembly 6 is lowered to the neutral suspension point, as follows. Figure 24 As shown.

[0097] In step 59, the cover cable guide 25 is removed from the cover 2, and then the anchor 10 is removed from the base plate 13 using a tightening tool, and the cable 8 is retracted back onto the winch 7.

[0098] After the cable 8 is retracted back onto the winch 7, the winch assembly 6 is removed together with the trolley assembly 5 (step 60).

[0099] At step 61, the cap is secured with a long-term fastener, and all short-term fasteners installed at step 57 are replaced with long-term fasteners.

[0100] Although the invention has been described in particular with respect to a swingable cover for a steam generator, it should be understood that the described invention or aspects thereof can be advantageously used in other fields where controlled opening and closing of a re-cover is required.

Claims

1. An actuator (1) for opening and closing a swing cover (2) for an access hole (3) of a steam generator (4), the actuator (1) comprising a trolley assembly (5) and a winch assembly (6), the winch assembly (6) being detachably mounted to the trolley assembly (5) and comprising a winch (7) provided with a pair of cables (8), characterized in that, The winch assembly (6) is used to engage the swing cover (2) and is also provided with a pair of hooks (9) and two threaded anchors (10). The pair of hooks (9) are used to suspend the winch assembly (6) on the shaft (2a) of the swing cover (2). Each anchor (10) is attached to the end of one of the cables (8) and is used to pass through the first through hole (2b) of the swing cover (2) and be threaded to the internal thread (11) of the second hole (12) provided on the base plate (13) of the steam generator (4) to provide a support point for the associated cable (8). The winch (7) is adapted to wind up and wind out the cable (8) so that the swing cover (2) can rotate between a closed cover position and an open cover position, in which the first through hole (2b) is aligned with the second hole (12) and in which the swing cover (2) is at a neutral suspension point.

2. The manipulator (1) according to claim 1, wherein, The winch assembly (6) is also provided with a positioning device (14) for cooperating with an associated receiving device (15) provided on the swing cover (2) to ensure the correct position of the winch assembly (6) relative to the swing cover (2).

3. The manipulator (1) according to claim 2, wherein, The positioning device (14) includes a pair of positioning cones (16), and the receiving device (15) includes a pair of second through holes (17) disposed between the shaft (2a) and the first through hole (2b), each positioning cone (16) being designed to be inserted into a second through hole (17).

4. The manipulator (1) according to any one of claims 1 to 3, wherein, Each hook (9) includes a body (9a) and a rotatably mounted gripper (9b) that is movable between an open position and a closed position. When the gripper (9b) is in the closed position, the body (9a) and the gripper (9b) together define an elliptical lateral opening (9c).

5. The manipulator (1) according to any one of claims 1 to 4 further includes a cable guide (22) associated with each of the cables (8).

6. The manipulator (1) according to claim 5, wherein, The cable guide device (22) includes a pair of guide wheels (23) associated with each of the cables (8) and disposed on the frame (24) of the winch assembly (6).

7. The manipulator (1) according to claim 5 or 6, wherein, The cable guide device (22) includes a cover cable guide (25) and a substrate cable guide (26) which are detachably mounted on the cover (2) and the substrate (13), respectively.

8. The manipulator (1) according to any one of claims 1 to 7, wherein, The handcart assembly (5) is provided with a lifting device (18) suitable for vertically shifting the winch assembly (6).

9. A method for opening a closed swing cover (2) using a manipulator (1) according to any one of claims 1 to 8, comprising the following steps: -Approach the cover shaft (2a) with the manipulator (1). -The winch assembly (6) is suspended on the cover shaft (2a). - Separate the winch assembly (6) from the handcart assembly (5), - Pull the cable (8) through the cover (2) and pass the anchor (10) through the substrate (13). - Wind up the cable (8) to lift the winch assembly (6) onto the cover (2) until the winch assembly (6) engages the cover (2). - Completely loosen the cover (2) from the substrate (13), - Unwind the cable (8) to lower the cover (2) until the neutral suspension point corresponding to the open cover position is reached. - Unwind the cable (8) until fully relaxed and remove the anchor (10) from the substrate (13), and wind the cable (8) onto the winch (7), and Remove the winch assembly (6) together with the trolley assembly (5).

10. A method for closing an opened swing cover (2) using a manipulator (1) according to any one of claims 1 to 8, comprising: -Approach the cover (2) with the manipulator (1). - To engage the cover (2) with the winch assembly (6), -The winch assembly (6) is suspended on the cover shaft (2a). - Separate the winch assembly (6) from the handcart assembly (5), - Pull the cable (8) through the cover (2) and pass the anchor (10) through the substrate (13). -Roll up the cable (8) to raise the cover (2) to the closed position. - In the closed position, the cover (2) is briefly fastened to the substrate (13). - Wind the cable (8) out until it is fully relaxed to lower the winch assembly (6) from the cover (2). Remove the anchor (10) from the substrate (13) and retrieve the cable (8) from the winch (7). - Remove the winch assembly (6) together with the trolley assembly (5), and - Secure the cover (2) to the substrate (13) for a long time.

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