A lifting device for position indicator and a lifting method thereof

Abstract

The present invention belongs to the technical field of nuclear power plant reactor maintenance, and specifically relates to a lifting device for a position indicator and a lifting method thereof. The device comprises a position indicator retrieval device and a position indicator lifting device. The position indicator retrieval device removes the position indicator, and the position indicator lifting device lifts the position indicator removed by the position indicator retrieval device. The present invention solves the technical problem that existing position indicator lifting devices cannot lift position indicators simultaneously, resulting in a long overhaul critical path time, a large amount of solid waste generated, a large collective radiation dose to workers, and a tendency for lifting interruptions to occur during the lifting process.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power plant reactor maintenance, and particularly relates to a lifting device for a position indicator and a lifting method thereof. Background Art

[0002] The reactor control rod drive mechanism, along with the drive rods and control rod assemblies, serves as the actuator of the reactor control and protection system. Position indicators, a key component of the reactor control rod drive mechanism, number 103 and are used to monitor the position of the drive rods and control rod assemblies. These position indicators provide position indications for every 20mm of travel within the core. During the unit overhaul, the existing hoisting equipment for hoisting position indicators can only lift one position indicator at a time, and using the existing hoisting equipment takes approximately 44 hours of the overhaul critical path. The collective radiation dose to workers was approximately 14 man·mSv.

[0003] After a fuel cycle, the sealing gasket expands, causing the position indicator to adhere to the pressure hull. This increases the probability of interruptions when hoisting the position indicator, further increasing critical path time and collective dose. Furthermore, using existing hoisting equipment to operate the position indicator consumes approximately 150 sets of paper clothing, all of which are radioactive solid waste, placing a certain pressure on the environment.

[0004] At the same time, during the process of hoisting the position indicator to the position indicator storage rack, the core operators need to frequently evacuate to the low-dose waiting area or even climb a vertical ladder as high as 4 meters, which consumes a lot of physical energy of the operators.

[0005] Therefore, it is necessary to design a lifting device and a lifting method for a position indicator to solve the technical problems generated when the position indicator is lifted using the existing technology. Summary of the Invention

[0006] In response to the existing technology, the present invention proposes a lifting device for a position indicator and a lifting method thereof, which are used to solve the technical problems that the existing position indicator lifting device cannot lift the position indicator at the same time, resulting in a long overhaul critical path time, a large amount of solid waste generated, a large collective radiation dose to the workers, and easy lifting interruption during the lifting process.

[0007] The technical solution of the present invention:

[0008] A lifting device for a position indicator comprises: a position indicator taking-out device and a position indicator lifting device. The position indicator taking-out device takes out the position indicator, and the position indicator lifting device lifts the position indicator taken out by the position indicator taking-out device.

[0009] The position indicator removal device includes: a support frame, a screw A and a claw; a mounting hole is opened at the top center position of the support frame, one end of the screw A passes through the mounting hole, and the screw A is fixedly set at the top center position of the support frame, and a claw is fixedly set at the bottom of the screw A, and the threaded part on the screw A is coated with a molybdenum disulfide coating.

[0010] The lifting device of the position indicator includes: a plurality of lifting ears A, a lifting beam, a plurality of lifting ears B, a plurality of rotating rings, a plurality of position indicator connecting parts, a screw B and a guide groove; a plurality of lifting ears A are welded at equal intervals on the top of the lifting beam; a guide groove is provided on the surface of the lifting beam; and the screw B is fixedly arranged on the lifting beam.

[0011] The surface of the screw rod B includes a threaded portion and a non-threaded portion. A plurality of screw rod nuts are provided on the threaded portion of the screw rod B. The middle portions of all the lifting ears B are sleeved on the screw rod B.

[0012] The middle of each lifting lug B is fixed on the screw rod B with equal intervals through a screw nut; the top of each lifting lug B is set in the guide groove, and the lower end of each lifting lug B is connected to a position indicator connecting component through a rotating ring.

[0013] The threaded portion of the screw rod B is coated with a molybdenum disulfide coating.

[0014] The number of the lifting lug A, the lifting lug B, the rotating ring and the indicator connecting component is three, and the position indicator connecting component is a "T"-shaped structure as a whole.

[0015] The rotating ring includes: an upper lifting ring, a lower lifting ring and a connecting bolt connecting the upper and lower lifting rings. The upper lifting ring is connected to the connecting ear B, and the lower lifting ring is connected to the position indicator connecting component. The upper lifting ring and the lower lifting ring are connected by the connecting bolt and can achieve ° free rotation around the connecting bolt to realize the rotation direction of the position indicator during the lifting process.

[0016] The position indicator connecting component includes: a suspension rod, a positioning ring and several connecting screws, one end of the suspension rod is connected to the lower suspension ring of the rotating ring, and the other end of the suspension rod is connected to the positioning ring, and the positioning ring is used to match and position the position indicator head; the several connecting screws are respectively arranged on two symmetrical sides of the positioning ring, and the connecting screws are used to connect to the suspension holes of the position indicator head.

[0017] The number of the connecting screws is two.

[0018] A method for lifting the lifting device for a position indicator as described above comprises the following steps:

[0019] Step 1: Check the position indicator removal device to ensure that the claw and screw A of the position indicator removal device are in the working position. Connect the claw of the position indicator removal device to the reducer of the position indicator head. Use a wrench to turn screw A on the claw to release the position indicator from the pressure hull and remove the position indicator.

[0020] Step 2: Gently place the position indicator removed by the position indicator removal device in step 1 onto the head of the moving assembly. Turn the screw A on the claw to release the connection between the claw on the position indicator removal device and the position indicator.

[0021] Step 3: Check the position indicator lifting device, including: checking the adjustability of the screw nut between the lifting lugs B on the position indicator lifting device, the integrity of the lifting lugs B, and whether the connecting parts between the rotating ring and the position indicator are loose;

[0022] The threaded portion of screw B is coated with molybdenum disulfide. Adjust the screw nut on screw B and move the lifting lug B in the guide groove so that the distance between the three position indicator connecting parts is equal to the distance between the three position indicators in the core.

[0023] Step 4: Connect the crane hook to the three lifting lugs A on the top of the position indicator lifting device through the lifting strap, ensuring a secure connection. Move the crane over the position indicator. After alignment is complete, adjust the rotating ring so that the lifting point of the position indicator connecting component is connected to the lifting point of the position indicator head.

[0024] Step 5: Use the crane to lift the position indicator at normal speed until the bottom of the position indicator is above the highest obstacle in the lifting process. Turn the crane to move the position indicator to the side of the position indicator storage rack. Adjust the lead screw nut on the position indicator lifting device again so that the distance between the three lifting lugs B is equal to the distance between the storage positions on the position indicator storage rack.

[0025] When adjusting the lead screw nut on the lead screw B, the lifting ears B on the left and right sides can be adjusted to the same distance at the same time to ensure that the position indicators on the left and right sides always remain balanced during the adjustment process; place the position indicator on the storage shelf, record the coordinates and factory number of the position indicator with stainless steel tape, and then stick it to the corresponding position indicator; at the same time, disengage the position indicator lifting device.

[0026] Beneficial effects of the present invention:

[0027] 1) The position indicator hoisting device designed in this invention can simultaneously hoist three position indicator devices, saving about 20 hours of overhaul critical path time. Converted into power generation, a single overhaul of a single unit can generate about 8 million in revenue, and the four units can generate a total revenue of about 1 billion yuan over the unit's lifespan.

[0028] 2) The hoisting device for the position indicator designed in the present invention can reduce the collective radiation dose of workers during a single overhaul by approximately 8 man·mSv;

[0029] 3) The position indicator removal device designed in the present invention can eliminate the possibility of the position indicator sticking to the pressure hull before hoisting the position indicator, thus avoiding hoisting interruption accidents and rework.

[0030] 4) The position indicator lifting device and lifting method designed by the present invention not only reduces the operation time but also the number of workers, saving about 100 sets of radioactive paper clothes and reducing environmental pressure;

[0031] 5) The hoisting device and hoisting method of the position indicator designed by the present invention can reduce the number of hoisting times by 2 / 3. During the hoisting process to the position indicator storage rack, the operators can reduce the number of times they evacuate to the low-dose waiting area or even climb a straight ladder as high as 4 meters, thereby saving a lot of physical energy of the operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the position indicator lifting device of the present invention;

[0033] Figure 2 This is a schematic structural diagram of the position indicator removal device of the present invention.

[0034] Among them: 1-lifting ear A; 2-lifting beam; 3-lifting ear B; 4-rotating ring; 5-position indicator connecting part; 6-screw B; 7-guide groove; 8-support frame; 9-screw A; 10-claw, 11-lifting rod, 12-positioning ring, 13-connecting screw. DETAILED DESCRIPTION

[0035] A lifting device for a position indicator and a lifting method thereof according to the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0036] A lifting device for a position indicator, comprising: a position indicator removal device (such as Figure 2 as shown) and position indicator lifting device (as shown Figure 1 As shown), the position indicator taking-out device takes out the position indicator, and the position indicator hoisting device hoists the position indicator taken out by the position indicator taking-out device.

[0037] The position indicator removal device includes: a support frame 8, a screw A9 and a claw 10; a mounting hole is opened at the top center position of the support frame 8, one end of the screw A9 passes through the mounting hole, and the screw A9 is fixedly set at the top center position of the support frame 8, and a claw 10 is fixedly set at the bottom of the screw A9, and the threaded part on the screw A9 is coated with a molybdenum disulfide coating.

[0038] The lifting device of the position indicator includes: several lifting ears A1, a lifting beam 2, several lifting ears B3, several rotating rings 4, several position indicator connecting parts 5, a screw B6 and a guide groove 7; several lifting ears A1 are welded at equal intervals on the top of the lifting beam 2; a guide groove 7 is opened on the surface of the lifting beam 2; the screw B6 is fixedly set on the lifting beam 2.

[0039] The surface of the screw rod B6 includes a threaded portion and a non-threaded portion. A plurality of screw nuts are provided on the threaded portion of the screw rod B6. The middle portions of all the lifting ears B3 are looped around the screw rod B6.

[0040] The middle of each lifting ear B3 is fixed with equal-spaced threads on the screw rod B6 through a screw nut, and the positions of the three lifting ears B3 can also be adjusted back and forth on the screw rod B6 through the screw nuts between the three lifting ears B3.

[0041] The top of each lifting lug B3 is arranged in the guide groove 7 , and the lower end of each lifting lug B3 is connected to a position indicator connecting component 5 through a rotating ring 4 .

[0042] The threaded portion of the screw rod B6 is coated with a molybdenum disulfide coating.

[0043] The number of the lifting lug A1, lifting lug B3, rotating ring 4 and indicator connecting component 5 is three, which can meet the requirement of simultaneously lifting three position indicators in the reactor. The position indicator connecting component 5 is a "T"-shaped structure as a whole.

[0044] The rotating ring 4 includes: an upper lifting ring, a lower lifting ring and connecting bolts connecting the upper and lower lifting rings. The upper lifting ring is connected to the connecting ear B3, and the lower lifting ring is connected to the position indicator connecting component 5. The upper lifting ring and the lower lifting ring are connected by the connecting bolts and can achieve 360° free rotation around the connecting bolts to realize the rotation direction of the position indicator during the lifting process.

[0045] The position indicator connecting component 5 includes: a suspension rod 11, a positioning ring 12 and a plurality of connecting screws 13. One end of the suspension rod 11 is connected to the lower suspension ring of the rotating ring 4, and the other end of the suspension rod 11 is connected to the positioning ring 12. The positioning ring 12 is used to match and position the position indicator head; the plurality of connecting screws 13 are respectively arranged on two symmetrical sides of the positioning ring 12, and the connecting screws 13 are used to connect to the suspension hole of the position indicator head.

[0046] The number of the connecting screws 13 is two.

[0047] A method for lifting the lifting device for a position indicator as described above comprises the following steps:

[0048] Before lifting, use a ratchet wrench and a special wrench to loosen the bolts 8-10 turns to release the seal of the casing, and then remove the shroud, casing, moving component flange and thrust ring in turn;

[0049] Step 1: Check the availability of the position indicator removal device. Ensure that the claw 10 and screw A9 of the position indicator removal device are in the working position. Connect the claw 10 of the position indicator removal device to the reducer of the position indicator head. Use a wrench to turn the screw A9 on the claw 10 to release the position indicator from the pressure hull and remove the position indicator.

[0050] Step 2: Gently place the position indicator removed by the position indicator removal device in step 1 onto the head of the moving assembly, and rotate the screw A9 on the claw 10 to release the connection between the claw 10 and the position indicator on the position indicator removal device;

[0051] Step 3: Check the position indicator lifting device, including: checking the adjustability of the screw nut between the lifting lugs B3 on the position indicator lifting device, the integrity of the lifting lugs B3, and whether the rotating ring 4 and the position indicator connecting component 5 are loose;

[0052] The threaded portion of the screw rod B6 is coated with molybdenum disulfide. Adjust the screw nut on the screw rod B6 and move the lifting lug B3 in the guide groove 7 so that the distance between the three position indicator connecting parts 5 is equal to the distance between the three position indicators in the core.

[0053] Step 4: Connect the crane hook to the three lifting ears A1 on the top of the position indicator lifting device through the lifting strap, ensuring a secure connection. Move the crane over the position indicator. After alignment is complete, adjust the rotating ring 4 so that the lifting point of the position indicator connecting component 5 is connected to the lifting point of the position indicator head.

[0054] Step 5: Use the crane to lift the position indicator at normal speed until the bottom of the position indicator is above the highest obstacle in the lifting process. Turn the crane to move the position indicator to the position indicator storage shelf. Adjust the lead screw nut on the position indicator lifting device again so that the distance between the three lifting ears B3 is equal to the distance between the storage positions on the position indicator storage shelf.

[0055] When adjusting the lead screw nut on the lead screw B6, the lifting ears B3 on the left and right sides can be adjusted to the same distance at the same time to ensure that the position indicators on the left and right sides always remain balanced during the adjustment process; place the position indicator on the storage shelf, record the coordinates and factory number of the position indicator with stainless steel tape, and then stick it to the corresponding position indicator; at the same time, disengage the position indicator lifting device.

[0056] The application of the above lifting method in actual work has achieved good economic and social benefits:

[0057] (1) A single overhaul of a single unit can generate approximately RMB 8 million in revenue, and the four units can generate a total revenue of approximately RMB 1 billion over the life of the unit;

[0058] (2) Save about 100 sets of paper clothes, reduce the generation of radioactive solid waste, and alleviate environmental pressure.

[0059] This device and lifting method can be promoted and applied in related work of the same type of units; the device of the present invention can also be extended to other similar work in power plants; it also has good reference significance for other similar work in the same industry.

[0060] The embodiments of the present invention are described in detail above. The present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A method for hoisting a hoisting device for a position indicator, characterized in that: The lifting device for the position indicator comprises: a position indicator taking-out device and a position indicator lifting device, wherein the position indicator taking-out device takes out the position indicator, and the position indicator lifting device lifts the position indicator taken out by the position indicator taking-out device; The position indicator removal device comprises: a support frame (8), a lead screw A (9) and a claw (10); a mounting through hole is provided at the top center position of the support frame (8), one end of the lead screw A (9) passes through the mounting through hole, and the lead screw A (9) is fixedly set at the top center position of the support frame (8); a claw (10) is fixedly set at the bottom of the lead screw A (9), and a threaded portion on the lead screw A (9) is coated with a molybdenum disulfide coating; The hoisting device of the position indicator comprises: a plurality of lifting ears A (1), a hanging beam (2), a plurality of lifting ears B (3), a plurality of rotating rings (4), a plurality of position indicator connecting parts (5), a screw B (6) and a guide groove (7); a plurality of lifting ears A (1) are welded at equal intervals on the top of the hanging beam (2); a guide groove (7) is provided on the surface of the hanging beam (2); the screw B (6) is fixedly arranged on the hanging beam (2); The surface of the screw B (6) includes a threaded portion and a non-threaded portion. A plurality of screw nuts are provided on the threaded portion of the screw B (6), and the middle portions of all the lugs B (3) are sleeved on the screw B (6). The middle part of each lifting lug B (3) is fixed to the lead screw B (6) with equal spacing through a lead screw nut; the top of each lifting lug B (3) is arranged in a guide groove (7), and the lower end of each lifting lug B (3) is connected to a position indicator connecting component (5) through a rotating ring (4); The threaded portion of the lead screw B (6) is coated with a molybdenum disulfide coating; the number of the lug A (1), the lug B (3), the rotating ring (4) and the position indicator connecting component (5) are all three, and the position indicator connecting component (5) is a "T"-shaped structure as a whole; The rotating ring (4) comprises an upper lifting ring, a lower lifting ring and a connecting bolt connecting the upper and lower lifting rings, wherein the upper lifting ring is connected to the connecting lug B (3), and the lower lifting ring is connected to the position indicator connecting component (5). The upper lifting ring and the lower lifting ring are connected by the connecting bolt and can freely rotate 360 degrees around the connecting bolt to realize the rotation direction of the position indicator during the lifting process; The position indicator connecting component (5) includes: a suspension rod (11), a positioning ring (12) and a plurality of connecting screws (13); one end of the suspension rod (11) is connected to the lower suspension ring of the rotating ring (4); the other end of the suspension rod (11) is connected to the positioning ring (12); the positioning ring (12) is used to match and position the position indicator head; the plurality of connecting screws (13) are respectively arranged on two symmetrical sides of the positioning ring (12); the connecting screws (13) are used to connect to the suspension holes of the position indicator head; the number of the connecting screws (13) is two; The method for lifting a lifting device for a position indicator comprises the following steps: Step 1: Checking the position indicator removal device to ensure that the claw (10) and the lead screw A (9) of the position indicator removal device are in the working position, connecting the claw (10) of the position indicator removal device to the head diameter reducing portion of the position indicator, using a wrench to rotate the lead screw A (9) on the claw (10) to release the adhesion between the position indicator and the pressure hull, and removing the position indicator; Step 2: Gently place the position indicator taken out by the position indicator taking-out device in step 1 onto the head of the moving assembly, rotate the screw A (9) on the claw (10), and release the connection between the claw (10) on the position indicator taking-out device and the position indicator; Step 3: Check the position indicator hoisting device, including: checking the adjustability of the screw nut between the lifting lugs B (3) on the position indicator hoisting device, the integrity of the lifting lugs B (3), and whether the rotating ring (4) and the position indicator connecting part (5) are loose; The threaded portion of the lead screw B (6) is coated with a molybdenum disulfide coating. The lead screw nut on the lead screw B (6) is adjusted to move the lug B (3) in the guide groove (7) so that the distance between the three position indicator connecting parts (5) is equal to the distance between the three position indicators in the core; Step 4: Connect the crane hook to the three lifting ears A (1) on the top of the position indicator lifting device through the lifting strap, ensuring that the connection is reliable, move the crane to the top of the position indicator, and after the alignment is completed, adjust the rotating ring (4) so that the lifting point of the position indicator connecting component (5) is connected to the lifting point of the position indicator head; Step 5: Use the crane to lift the position indicator at normal speed until the bottom of the position indicator exceeds the height of the highest obstacle during the lifting process, turn the crane, and move the position indicator to the position indicator storage rack; adjust the screw nut on the position indicator lifting device again so that the distance between the three lifting ears B (3) is equal to the distance of the storage position on the position indicator storage rack; when adjusting the screw nut on the screw B (6), the lifting ears B (3) on the left and right sides can be adjusted to the same distance at the same time, ensuring that the position indicators on the left and right sides always remain balanced during the adjustment process; place the position indicator on the storage rack, record the coordinates and factory number of the position indicator with stainless steel tape, and then stick it on the corresponding position indicator; and disconnect the position indicator lifting device at the same time.

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