Reactor coolant pump centering device and method

Abstract

The present invention belongs to the field of nuclear power engineering of nuclear power plants, and specifically relates to a reactor coolant pump centering device and method, including: a centering device support, a connecting device, a dial indicator adjustment rod and a dial indicator, the connecting device is located below the centering device support, the connecting device is fixedly connected to the centering device support, the dial indicator adjustment rod is slidably connected to the connecting device, and the dial indicator is installed on the dial indicator adjustment rod. The device of the present invention has a simple and light structure, is easy to install and disassemble, can meet the requirements of verifying and adjusting the coaxiality and parallelism of the reactor coolant pump and the motor, and avoids the processes of disassembling and installing the upper oil tank cover and the turning of the motor, and reduces the occupation of the ring hoist in the nuclear reactor hall during the nuclear reactor refueling overhaul process, thereby reducing the occupation of the key path, improving the maintenance efficiency, shortening the overhaul period, and increasing the economic benefits.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power engineering of nuclear power plants, and in particular relates to a reactor coolant pump centering device and method. Background Art

[0002] In the design and layout of a nuclear power plant, each unit has four reactor coolant pumps to establish the circulation of the coolant medium in the main circulation loop. The reactor coolant pump is a vertical single-stage centrifugal pump with a mechanical seal. The rotation direction is counterclockwise when viewed from the top of the motor. The motor matched with it is a vertical, two-speed, three-phase squirrel cage asynchronous motor. The motor and the pump are connected through a torsion bar coupling. When the motor is started, the pump rotor is driven to rotate through the torsion bar coupling, thereby establishing the main circulation loop circulation.

[0003] During the overhaul of the nuclear power plant reactor refueling, a single unit needs to involve at least one motor dismantling overhaul and one pump body dismantling overhaul. Before the rotor of the dismantled reactor coolant pump or motor is connected, the pump and the motor need to be aligned, that is, the coaxiality and parallelism are adjusted within the maintenance requirements. Because the pressure of the primary circuit is low during the maintenance process and the weight of the motor rotor is large, it is impossible to perform the alignment operation by manually turning the pump or motor rotor. The operation method in the manufacturer's maintenance manual is to remove the oil tank cover and oil return chamber on the motor, install an electric turning mechanism, drive the motor rotor by electric means, install the centering device on the torsion bar coupling connected to the motor, and perform the alignment operation by hitting the radial and axial directions of the pump with a dial indicator. In this process, the removal and installation of the upper bearing chamber of the motor and the removal and installation of the turning gear all require the use of a ring crane. The ring crane is a public lifting machinery in the nuclear reactor hall. Its occupation involves the progress of the critical path maintenance, affecting the unit's power generation time and the company's economic benefits.

[0004] Therefore, it is urgent to develop a reactor coolant pump centering device that can verify and adjust the coaxiality and parallelism of the pump and the motor while eliminating the work of disassembling and installing the reactor coolant pump motor. Summary of the invention

[0005] The object of the present invention is to provide a reactor coolant pump centering device and method, which has a simple and light structure and is easy to install and disassemble. It can meet the needs of verifying and adjusting the coaxiality and parallelism of the reactor coolant pump and the motor, while avoiding the processes of disassembling and installing the upper oil tank cover and the turning wheel of the motor, reducing the occupancy of the ring crane in the nuclear reactor hall during the overhaul of the nuclear reactor refueling, thereby reducing the occupancy of key paths, improving maintenance efficiency, shortening the overhaul period, and increasing economic benefits.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A reactor coolant pump centering device, the centering device comprising: a centering device support, a connecting device, a dial indicator adjustment rod and a dial indicator, the connecting device is located below the centering device support, the connecting device is fixedly connected to the centering device support, the dial indicator adjustment rod is slidably connected to the connecting device, and the dial indicator is installed on the dial indicator adjustment rod.

[0008] The centering device support comprises a top semicircular connecting unit and a bottom bearing transmission unit, and the bearing transmission unit and the connecting unit are fixedly connected.

[0009] The centering device comprises a centering device support that is symmetrical on both sides, and the centering device support that is symmetrical on both sides is connected to two first bolt holes through a first bolt to complete connection and positioning.

[0010] The circumferential diameter of the connection unit is larger than the diameter of the middle shaft of the torsion bar coupling.

[0011] The bearing transmission unit is provided with a first bearing and a second bearing in a radial matching direction and an axial matching direction, respectively.

[0012] The connecting device is fixedly connected to the centering device support through a second bolt installed in the second bolt hole.

[0013] The dial indicator adjustment rod comprises a radial adjustment rod and an axial adjustment rod.

[0014] A first metal block is welded to one end of the radial adjustment rod, and a first through hole is provided in the center of the first metal block. The diameter of the first through hole matches the diameter of the connecting rod, so that the first metal block can be installed on the connecting rod of the connecting device through the first through hole, and the radial adjustment rod can slide freely on the connecting rod through the first metal block, and the radial adjustment rod can be fixed on the connecting rod through the top screw on the side of the first metal block.

[0015] A second metal block is welded to one end of the axial adjustment rod, and a second through hole is provided in the center of the second metal block. The diameter of the second through hole matches the diameter of the radial adjustment rod, so that the second metal block can be installed on the radial adjustment rod through the second through hole, and the axial adjustment rod can slide freely on the radial adjustment rod through the second metal block, and the axial adjustment rod can be fixed on the radial adjustment rod through the top screw on the side of the second metal block.

[0016] The dial indicator is installed on the axial adjustment rod, and the dial indicator is fixed on the axial adjustment rod through the top screw on the side of the axial adjustment rod.

[0017] A reactor coolant pump centering method, the method comprising the following steps:

[0018] Step 1: Confirm that the reactor coolant pump and motor have been reinstalled, the motor support bolts have been tightened, and the torsion bar coupling has been raised and fixed to the motor rotor mating position through the torsion bar clamp;

[0019] Step 2: Install the symmetrically distributed centering device supports to the upper end surface of the bottom of the torsion bar coupling, use the first bolt to pass through the first bolt hole and tighten it, and confirm that the first bearing and the second bearing are tightly matched with the torsion bar coupling and the centering device supports can rotate freely on the torsion bar;

[0020] Step 3: Use the second bolt to pass through the second bolt hole, install the connecting device under the centering device support and fix it;

[0021] Step 4: Install the dial indicator to the axial adjustment rod and fix it with the top screw, install the radial adjustment rod to the connecting rod of the connecting device, and install the axial adjustment rod to the radial adjustment rod;

[0022] Step 5: Adjust the positions of the dial indicators so that the two dial indicators are respectively placed in the radial and axial directions of the reactor coolant pump casing, and use the top screws to fix the positions of the dial indicators, the axial adjustment rod, and the radial adjustment rod respectively;

[0023] Step 6: Manually rotate the support of the centering device for one circle to confirm that the rotation is flexible and there is no abnormality;

[0024] Step 7: Manually rotate the support of the centering device for one circle, and record the readings of the two dial indicators 8 times evenly divided into the circumference;

[0025] Step 8: Evaluate the alignment result based on the measurement result. If the result exceeds the standard, adjust the motor position by adjusting the motor support.

[0026] Step 9: Repeat the above steps until the measurement results meet the acceptance requirements;

[0027] Step 10: Disassemble the components of the reactor coolant pump centering device separately, and the work is completed.

[0028] The beneficial technical effects of the present invention are:

[0029] 1. The reactor coolant pump centering device provided by the present invention adopts a simple mechanical structure and standard parts, and reasonably utilizes some components of the original centering tool, so it is simple to manufacture and low in cost;

[0030] 2. The reactor coolant pump centering device provided by the present invention does not need to disassemble the main pump motor components when in use, reducing the burden on maintenance personnel; no external turning mechanism is required, reducing the use of other electric tools;

[0031] 3. The reactor coolant pump centering device provided by the present invention does not require the top opening of the motor during use, thereby reducing the risk of foreign matter entering the equipment and system;

[0032] 4. The reactor coolant pump centering device provided by the present invention is lightweight and can be installed by one or two people, thus saving labor costs;

[0033] 5. The reactor coolant pump centering device provided by the present invention does not require electricity, complicated control circuits and button operations, and can be used with simple training. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic structural diagram of a reactor coolant pump centering device provided by the present invention;

[0035] Figure 2 A schematic structural diagram of a centering device support in a reactor coolant pump centering device provided by the present invention;

[0036] Figure 3 A schematic diagram of the operation of a reactor coolant pump centering device provided by the present invention;

[0037] Figure 4 This is a partially enlarged view of the working schematic diagram of a reactor coolant pump centering device provided by the present invention.

[0038] In the figure: 1. Centering device support; 2. Connecting device; 3. Radial adjustment rod; 4. Axial adjustment rod; 5. Dial indicator; 6. First bolt; 7. Second bolt; 8. Top screw; 9. Bearing transmission unit; 10. Connecting unit; 11. First bearing; 12. Second bearing; 13. First bolt hole; 14. Second bolt hole; 15. Torsion bar coupling; 16. Reactor coolant pump; 17-Motor; 18-Motor flywheel. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0040] like Figure 1 As shown, a reactor coolant pump centering device provided by the present invention includes: a centering device support 1, a connecting device 2, a dial indicator adjustment rod and a dial indicator 5, the connecting device 2 is located below the centering device support 1, the connecting device 2 and the centering device support 1 are fixedly connected by a second bolt 7 installed in a second bolt hole 14, the dial indicator adjustment rod is slidably connected to the connecting device 2, and the connecting device 2 is used to connect the centering device support 1 and the dial indicator adjustment rod; the dial indicator 5 is installed on the dial indicator adjustment rod.

[0041] like Figure 2 As shown, the centering device support 1 is made of metal materials such as stainless steel or carbon steel, and includes a top semicircular connecting unit 10 and a bottom bearing transmission unit 9. The bearing transmission unit 9 and the connecting unit 10 can be integrally formed or processed separately according to machining conditions during the actual manufacturing process. The bearing transmission unit 9 and the connecting unit 10 are connected by bolts or welding.

[0042] The circumferential diameter of the semicircular connection unit 10 is larger than the diameter of the middle shaft of the torsion bar coupling 15 , and the centering device support 1 symmetrical on both sides is connected to the two first bolt holes 13 by the first bolt 6 to complete the connection and positioning.

[0043] The bearing transmission unit 9 is provided with a plurality of first bearings 11 and second bearings 12 in the radial matching direction and the axial matching direction. In this embodiment, there are two first bearings 11 on one side and one second bearing 12 on one side. The number can be increased or decreased according to the actual demand to ensure that the first bearing 11 and the second bearing 12 are closely matched with the torsion bar coupling 15 after the centering device supports 1 on both sides are connected by the first bolts 6.

[0044] like Figure 1 As shown, the connection device 2 is made of metal materials such as stainless steel or carbon steel, and includes a connection head and a connection rod, which are connected by bolts or welding, and the connection block is fixedly connected to the centering device support 1 by a second bolt 7 installed in the second bolt hole 14, and the free end of the connection rod is located in a direction away from the centering device support 1. The connection device 2 can adopt the structure used to connect the torsion bar coupling and the dial indicator adjustment rod in the original nuclear power plant maintenance tool, and the structure of the connection device 2 can be designed and adjusted according to the position and size of the second bolt hole 14.

[0045] like Figure 1 As shown, the dial gauge adjustment rod includes a radial adjustment rod 3 and an axial adjustment rod 4, and the radial adjustment rod 3 and the axial adjustment rod 4 are made of metal materials such as stainless steel or carbon steel. The radial adjustment rod 3 and the axial adjustment rod 4 can be made of steel bars or steel pipes of finished sizes.

[0046] A first metal block is welded to one end of the radial adjustment rod 3, and a first through hole is provided in the center of the first metal block. The diameter of the first through hole matches the diameter of the connecting rod, so that the first metal block can be installed on the connecting rod of the connecting device through the first through hole. The radial adjustment rod 3 slides freely on the connecting rod through the first metal block, and the radial adjustment rod 3 is fixed on the connecting rod through the top screw 8 on the side of the first metal block.

[0047] A second metal block is welded to one end of the axial adjustment rod 4, and a second through hole is provided in the center of the second metal block. The diameter of the second through hole matches the diameter of the radial adjustment rod 3, so that the second metal block can be installed on the radial adjustment rod 3 through the second through hole, and the axial adjustment rod 4 can slide freely on the radial adjustment rod 3 through the second metal block, and the axial adjustment rod 4 can be fixed on the radial adjustment rod 3 through the top screw 8 on the side of the second metal block.

[0048] like Figure 1 As shown, the dial gauge 5 is mounted on the axial adjustment rod 4, and the dial gauge 5 is fixed on the axial adjustment rod 4 by means of the top screw 8 on the side of the axial adjustment rod 4. Figure 3As shown, when the centering device is used to align the reactor coolant pump and the motor, two dial indicators 5 are respectively struck on the radial and axial directions of the pump housing of the reactor coolant pump 16 and fixed by the top screw 8 on the axial adjustment rod 4.

[0049] The reactor coolant pump centering device provided by the present invention is used to center the reactor coolant pump and the motor, and the specific steps are as follows:

[0050] Step 1: Confirm that the reactor coolant pump 16 and the motor 17 have been reinstalled, the motor support bolts have been tightened, and the torsion bar coupling 15 has been raised and fixed to the motor rotor matching position through the torsion bar clamp;

[0051] Step 2, install the symmetrically distributed centering device support 1 to the upper end surface of the bottom of the torsion bar coupling 15, use the first bolt 6 to pass through the first bolt hole 13 and tighten it, and confirm that the first bearing 11 and the second bearing 12 are tightly matched with the torsion bar coupling 15 and the centering device support 1 can rotate freely on the torsion bar;

[0052] Step 3: Use the second bolt 7 to pass through the second bolt hole 14, install the connecting device 2 below the centering device support 1 and fix it;

[0053] Step 4, install the dial indicator 5 to the axial adjustment rod 4 and fix it with the top screw 8, install the radial adjustment rod 3 to the connecting rod of the connecting device 2, and install the axial adjustment rod 4 to the radial adjustment rod 3;

[0054] Step 5, adjust the position of the dial gauge 5 so that the two dial gauges 5 are respectively hit in the radial direction and axial direction of the pump housing of the reactor coolant pump 16, and use the top screw 8 to fix the positions of the dial gauge 5, the axial adjustment rod 4 and the radial adjustment rod 3 respectively;

[0055] Step 6: Manually rotate the support 1 of the centering device for one circle to confirm that the rotation is flexible and there is no abnormality;

[0056] Step 7: Manually rotate the support 1 of the centering device for one circle, and record the readings of the two dial indicators 5 8 times evenly divided into the circumference;

[0057] Step 8: Evaluate the alignment result based on the measurement result. If the result exceeds the standard, adjust the motor position by adjusting the motor support.

[0058] Step 9: Repeat the above steps until the measurement results meet the acceptance requirements;

[0059] Step 10: Disassemble the components of the reactor coolant pump centering device separately, and the work is completed.

[0060] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. A method for centering a reactor coolant pump, characterized in that: The reactor coolant pump centering device used in the method comprises: A centering device support (1), a connecting device (2), a dial indicator adjustment rod and a dial indicator (5), wherein the connecting device (2) is located below the centering device support (1), the connecting device (2) is fixedly connected to the centering device support (1), the dial indicator adjustment rod is slidably connected to the connecting device (2), and the dial indicator (5) is mounted on the dial indicator adjustment rod; The centering device support (1) comprises a top semicircular connecting unit (10) and a bottom bearing transmission unit (9), wherein the bearing transmission unit (9) and the connecting unit (10) are fixedly connected; The centering device comprises a centering device support (1) that is symmetrical on both sides, and the centering device support (1) that is symmetrical on both sides is connected to two first bolt holes (13) via a first bolt (6) to complete connection and positioning; The circumferential diameter of the connecting unit (10) is larger than the diameter of the middle shaft of the torsion bar coupling (15); The bearing transmission unit (9) is provided with a first bearing (11) and a second bearing (12) in a radial matching direction and an axial matching direction respectively; The connecting device (2) is fixedly connected to the centering device support (1) via a second bolt (7) installed in a second bolt hole (14); The dial gauge adjustment rod comprises a radial adjustment rod (3) and an axial adjustment rod (4); The method comprises the following steps: Step 1: Confirm that the reactor coolant pump (16) and the motor (17) have been reinstalled, the motor support bolts have been tightened, and the torsion bar coupling (15) has been raised and fixed to the motor rotor matching position through the torsion bar clamp; Step 2: Install the symmetrically distributed centering device support (1) to the upper end surface of the bottom of the torsion bar coupling (15), use the first bolt (6) to pass through the first bolt hole (13) and tighten it, and confirm that the first bearing (11) and the second bearing (12) are tightly matched with the torsion bar coupling (15) and the centering device support (1) can rotate freely on the torsion bar; Step 3: Use the second bolt (7) to pass through the second bolt hole (14), install the connecting device (2) below the centering device support (1) and fix it; Step 4: Install the dial indicator (5) to the axial adjustment rod (4) and fix it with the top screw (8), install the radial adjustment rod (3) to the connecting rod of the connecting device (2), and install the axial adjustment rod (4) to the radial adjustment rod (3); Step 5, adjusting the positions of the dial gauges (5) so that the two dial gauges (5) are respectively placed in the radial and axial directions of the pump housing of the reactor coolant pump (16), and using the top screw (8) to respectively fix the positions of the dial gauge (5), the axial adjustment rod (4), and the radial adjustment rod (3); Step 6: Manually rotate the centering device support (1) for one circle to confirm that the rotation is flexible and without abnormality; Step 7, manually rotate the centering device support (1) for one circle, and record the readings of the two dial indicators (5) 8 times evenly divided according to the circumference; Step 8: Evaluate the alignment result based on the measurement result. If the result exceeds the standard, adjust the motor position by adjusting the motor support. Step 9: Repeat the above steps until the measurement results meet the acceptance requirements; Step 10: Disassemble the components of the reactor coolant pump centering device separately, and the work is completed.

2. A reactor coolant pump centering method according to claim 1, characterized in that: A first metal block is welded to one end of the radial adjustment rod (3), a first through hole is provided at the center of the first metal block, and the diameter of the first through hole matches the diameter of the connecting rod, so that the first metal block is installed on the connecting rod of the connecting device through the first through hole, and the radial adjustment rod (3) slides freely on the connecting rod through the first metal block, and the radial adjustment rod (3) is fixed on the connecting rod through the top screw (8) on the side of the first metal block.

3. A reactor coolant pump centering method according to claim 1, characterized in that: A second metal block is welded to one end of the axial adjustment rod (4), a second through hole is provided at the center of the second metal block, and the diameter of the second through hole matches the diameter of the radial adjustment rod (3), so that the second metal block is installed on the radial adjustment rod (3) through the second through hole, the axial adjustment rod (4) slides freely on the radial adjustment rod (3) through the second metal block, and the axial adjustment rod (4) is fixed on the radial adjustment rod (3) through the top screw (8) on the side of the second metal block.

4. A reactor coolant pump centering method according to claim 1, characterized in that: The dial gauge (5) is mounted on the axial adjustment rod (4), and the dial gauge (5) is fixed on the axial adjustment rod (4) via a top screw (8) on the side of the axial adjustment rod (4).

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