JP3346882B2 - Shaft handling tool for internal pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft handling device for an internal pump used for raising an impeller and a shaft of an internal pump employed in an improved boiling water reactor from reactor water.

[0002]

2. Description of the Related Art In an improved boiling water reactor (ABWR), a plurality of internal pumps 60 are mounted around the bottom of a reactor pressure vessel 35 as shown in FIG.
The internal pump 60 has a structure as shown in FIG.

FIG. 5 (a) schematically shows an improved boiling water reactor. That is, inside the reactor pressure vessel 35, the outside of the reactor core including a large number of fuel assemblies 56 and a plurality of control rods 57 is surrounded by the shroud 34. The control rod 57 is connected to a drive mechanism 59 that moves in the guide tube 58.

A shroud head is provided at the top of the shroud 34.
A steam-water separator 54 and a steam dryer 53 are arranged on the shroud head 55. The upper end opening of the reactor pressure vessel 35 is closed by a pressure vessel head 52. The reactor pressure vessel 35 is installed in the reactor containment vessel 50, and a head 51 is provided at the upper opening of the reactor containment vessel 50 and is hermetically closed.

A refueling machine 48 and an equipment pool 49 are provided on the operation floor above the reactor containment vessel 50. A hoist 61 is installed in the refueling machine 48, and a wire rope 62 is hung from the hoist 61. Shroud
A guide rail 64 is attached to the outside of 34.

FIG. 5B shows the internal pump 60 with the head 51, the pressure vessel head 52, the steam dryer 53, the steam separator 54, and the shroud head 55 removed from the operation state of the reactor shown in FIG. This shows a state during the periodic inspection of the reactor to which the impeller shaft handling tool 63 is attached.

FIG. 6A shows a state in which the internal pump 60 is attached to the reactor pressure vessel 35. The internal pump 60 mainly includes a tapered cylindrical casing 36,
The motor includes a motor 46 in the casing 36, an impeller 38 in the reactor pressure vessel 35, a shaft 39 to which the impeller 38 is attached and rotated by the motor 46, and a diffuser 41 surrounding the impeller 38.

The diffuser 41 has a diffuser boss 42 mounted on a stub tube 40 and pulled downward by a stretch tube 43, and a lower end of the stretch tube 43 is fixedly fastened to a neck portion of a casing 36 by a tightening nut 44. Have been. A wear ring 37 is provided on the upper inner surface of the diffuser 41, and an impeller 38 is arranged in the wear ring 37.

The shaft 39 has, as shown in FIG. 6B, an upper stud 30 on which an impeller 38 is mounted, and a lower stud 47 which is mounted in a casing 36 on a lower part. In FIG. 6A, reference numeral 45 in FIG. 6A denotes a secondary seal, and when pressurized, prevents a leak of reactor water which flows in close contact with the outer periphery of the shaft 39 when it is pressurized.

The lower stud 47 is for fixing a thrust disk to the end of the shaft 39. The thrust disk applies an upward thrust to the thrust bearing when the impeller 38 is operated and a downward thrust when the impeller 38 is stopped. Reference numeral 34a denotes a water channel through which cooling water flows into the reactor core, and a discharge port of the diffuser 41 is provided toward the water channel 34a.

When disassembling and assembling the internal pump 60 of the improved boiling water reactor, the impeller 38 and the shaft 39 are attached and detached, and the impeller 38 and the shaft 39 are handled by lifting or hanging the impeller and the shaft. A tool (hereinafter, referred to as a shaft handling tool) is used.

Generally, in such a case, the operation is performed in the furnace water, and as shown in FIG. 5B, a shaft handling tool is attached to the tip of the wire rope 62 of the auxiliary hoist 61 of the refueling machine 48 on the furnace, for example. It is carried out by fixing 63, and is carried out by remote control from the refueling machine.

At the time of periodic inspection, maintenance and inspection work of the internal pump is performed, and disassembly, inspection and reassembly of the internal pump are performed. As shown in FIG. 6 (a), the upper part of the impeller 38 and the shaft 39 of the internal pump 60 is provided between the inside of the reactor pressure vessel 35 and the outside of the shroud 34, and the lower parts of the motor 46 and the shaft 39 Reactor pressure vessel
It is incorporated in a casing 36 provided at the bottom of 35.

Therefore, the working space of the internal pump 60 is small, and it is difficult to visually inspect and inspect it with an underwater television camera. An inspection is performed.

The impeller 38 and the shaft 39 of the internal pump 60 are heavy, have a long overall length of 3.5 m, and are installed near the bottom in the reactor pressure vessel 35. For this reason, the handling operation is carried out by suspending the shaft handling tool 63 from the auxiliary hoist 61 of the fuel changing machine 48 running on the furnace and hanging it below the furnace.

That is, the function of the shaft handling tool 63 is to reliably hold or release the impeller 38 and the shaft 39. Impeller 38 and shaft 39 are impeller
Since the upper stud 30 provided at the center of 38 is tightened and integrated, the work is usually performed by directly holding or releasing the stud 30. Therefore, the impeller 38 and the shaft 39 are handled as a single unit when they are removed from the internal pump 60 or when they are mounted.

As described above, the guide rail 64 is provided on the outside of the shroud 34, so that a space with poor visibility in a narrow place can be guided to the internal pump.

Since infiltration of reactor water into the casing 36 is strictly prohibited, the casing 39 is
The inside of 36 is filled with fresh water, and the shaft 39 is removed and mounted. Thus, the work of attaching and detaching the shaft 39 needs to rely on a shaft handling tool that is remotely operated from the upper part of the furnace.

[0019]

First, it is necessary that the upper stud 30 of the shaft 39 be securely gripped and that once it is locked, it does not come off during the transfer of the shaft 39. In other words, a fall accident in the furnace cannot be recovered without enormous work in consideration of the post-treatment, and thus is an issue that is naturally required.

Secondly, it must function reliably in underwater remote control in a small place and be safely remote-controlled. That is, when the long shaft 39 is pulled up from the core and moved into the equipment pool 49 on the operation floor and placed horizontally, there is a problem that the hanging portion and the latch portion need to be articulated and bend freely. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and improves the maintenance and inspection work of an internal pump more efficiently and labor-saving, and makes it easier and more reliable to pull up an impeller and a shaft, which are relatively difficult. An object of the present invention is to provide a shaft handling tool for an internal pump that can be performed.

[0022]

Means for Solving the Problems The invention according to claim 1,
A post, a frame provided on the upper portion of the strut, a sliding pin provided slidably through the frame,
A spring for biasing the slide pin downward, the hanging lifting studs that are attached to <br/> upper portion of the sliding pin, the lower part of the strut
A bendably connected wall plate and a pin provided on the wall plate
A piston and cylinder Da, Piscataway be within the cylinder
A spring for biasing the ton downward, and connected to the piston
And attached to the piston head below the piston shaft has a lever which is connected to the piston head, and a guide plate connected to the lower portion of the wall plate in sliding contact with the lever of the inner surface, pre
The lever is rotatably attached to the guide plate and is moved up and down by the lever.
To open and close the upper
A plurality of latch pieces engaging with the frame, the frame, the support,
And a flow path of a pressurized fluid that is provided in the wall plate and drives the cylinder, when the sliding pin moves upward.
The flow path of the pressurized fluid is shut off .

[0023]

The latch piece is engaged around the head stud using a piston that moves up and down with the piston. This piston works by pressurizing the cylinder. Further, the mechanical lock mechanism locks the pusher down with the piston, and then slides the sliding pin for winding the wire rope of the auxiliary hoist.

When the pressurizing circuit for operating the piston is inevitably shut off, the locked state can be maintained during the lifting operation of the impeller and the shaft. For example, the locked state is maintained even if reverse pressure (release operation) is erroneously made. Operation is not possible.

Further, since the pneumatic circuit is connected between the flange and the support, even if the flange boss is bent by 90 °, the lock of the latch piece by the pneumatic circuit does not change. Therefore, the impeller and the shaft can be placed horizontally.

The contact piece acts on the valve to operate the pneumatic relay at the upper and lower limits of the piston. The valve is also incorporated in the cap so that the initial position of the shaft handling tool for gripping and locking or unlocking can be achieved. Can be confirmed on the furnace via a pneumatic relay.

That is, during the regular inspection work of the nuclear reactor, the internal pump is removed and installed. At this time, after the casing is filled with fresh water, the impeller and the shaft are removed.

The shaft handling device is connected to the tip of the wire rope of the auxiliary hoist of the refueling machine and is suspended. The air cylinder is pressurized to elevate the piston and raise the ram to open the latch piece.

The shaft handling tool is gradually suspended and moved to a position directly above the internal pump. The cap is put on the head of the upper stud, the pneumatic relay is activated by opening the pneumatic valve, and lighting of the completion of positioning is performed. The counter pressure (gripping side air pressure) is applied to the air cylinder, and the latch piece is locked by the armature.

After the lock by the pneumatic valve is completed, the impeller and the shaft are simultaneously pulled up. Since the sliding pin below the suspension stud slides due to the load applied to the impeller and the shaft to cut off the pressurizing circuit of the cylinder, the piston cannot be operated during the lifting operation of the impeller and the shaft.

In a state where the air cylinder is moved to a predetermined position on the fuel pool side, for example, in a rack, the piston is lifted by applying a reverse pressure to the air cylinder to release the lock, and only the shaft handle is removed. When the shaft handling tool is seated, the sliding pin returns to its original position by the spring force, so that the piston can be raised by pressing the air cylinder.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a shaft handling tool for an internal pump according to the present invention will be described with reference to FIGS. FIG. 1A shows an overall view of a shaft handling tool for an internal pump. FIG. 1B shows a state in which the head of the upper stud 30 attached to the tip of the impeller 38 is gripped (locked). FIG. 2 is a side view seen from the direction of arrows AA in FIG. In addition, in FIG. 1A, since the sliding pin is moved and unlocked, the air cylinder cannot be pressurized.

That is, in FIG. 1, the shaft handling tool is suspended by a wire rope (not shown) with the weight of the impeller and the shaft. A screw hole (not shown) is formed on the top surface of the suspension stud indicated by reference numeral 1, and FIG.
The metal fitting at the tip of the wire rope 62 of the auxiliary hoist 61 described in (b) is screwed. The hose joint indicated by reference numeral 2 is a cylinder
This is a lock release pressurizing circuit that pressurizes from below 16.

A hose joint indicated by reference numeral 3 is a circuit for the valve 22. When the hose 32 is connected and the valve 22 is opened, a pneumatic circuit flows and air pressure can be supplied to the air cylinder. The hose 32 is connected to a relay device and a compressor (not shown) on the furnace.

The frame denoted by reference numeral 4 is a hose joint 2, 3
And has a pneumatic circuit. At the center of the frame 4 is a sliding pin 31 having a spindle-cylinder relationship.
A through-hole through which is slidable is machined. The slide pin 31 is supported via the spring 10 and can slide. That is, the cap nut 11
The frame 4 supports the inner spring 10.

The outer side of the sliding pin 11 is provided with an O-ring and a hair passage corresponding to the hole of the frame 4, and the position shown in FIG. 1A is opened when the spring is contracted to the maximum. I have. Therefore, the circuit is interrupted.

The support 5 has its right side fixed and is integrated with the lower surface of the frame 4 by fastening or the like. A pressurizing circuit (a vertical space portion) of the cylinder 16 is formed in the support 5. This pressure circuit is connected to a circuit in the frame 4.

The column 6 is fixed on the left side, and is integrated with the lower surface of the frame 4 by fastening or the like. The control circuit in the frame 4 and the circuit in the column 6 (portion indicated by a broken line) are connected. Reference numerals 12 and 13 denote left and right flanges, and left and right supports 14 and 15.
The boss part is supported by. Right flange 13
Is connected to the cylinder 16 pressurizing circuit, and the left flange 12 is connected to the valve 22 circuit. In the support portion, the boss of the flange is on the shaft side, and the lateral hole of the support is on the bearing side.

The joint of each circuit is sealed on both sides with O-rings. Plate 7 on both sides is directly flange 1
The bosses 2 and 13 are fixed with screws or the like. Flanges 12, 13
Are bolted to the wall plates 14 and 15. A stopper 19 is bolted to the upper end inside the wall plate 14 to be fastened to the flange and integrated therewith, and a tail cover 20 is bolted and integrated in the middle.

The cylinder 16 is sandwiched between the insides of the two wall plates 14 and 15 between the stopper 19 and the tail cover 20. Wallboard 1
Reference numerals 4 and 15 further extend to guide the piston head 24 up and down, and are integrated with the guide plate 26 by fastening a lower end bolt or the like. A spring 17 is built in the cylinder 16 and the piston 18 is always
Is pressed.

Further, a circuit is opened from the end of the stopper 19 via the wall plate 14 via the flange 13. The piston 18 is provided with a packing in the center as a sliding surface with the inner wall of the cylinder 16 in combination with the piston shaft as shown in the figure, and the packing is fastened to the piston from both sides by glands.

The piston shaft 18a forms an O-ring seal when combined with the piston 18, and a tail cover 20 below the piston 18 also penetrates. This seal is a packing land seal method, and a suppressor 21 is used. Piston shaft 18a
The lower end of the is fixedly attached to the piston head 24 by screwing or the like. A lever 25 is screwed to both ends of the piston head 24 to be integrated.

The lever 25 is configured such that its flange can be engaged with the latch piece 29. The latch piece 29 is provided with pins 28 provided on both sides of a cap 27 attached to the guide plate 26.
The left and right are rotatably attached to a pair. The contact piece 23 fixed to the piston head 24 is for pressing the stem of the valve 22. In the figure, the valve 22 provided on the guide plate 26 is shown.
Of the stem is pressed. The guide plate 26 serves as a guide when the lever 25 slides.

In FIG. 1A, a hose 32 provided above the frame 4 is connected to a circuit (portion indicated by a broken line) of the frame 4 via a hose joint 3. The guide plate 8 fixes the tightened pin 9 inserted between the hanging stud 1 and the sliding pin 31 shown in FIG. By moving the same hole 4 up and down, the sliding pin 31 serves as a guide and rotation stop.

As is clear from FIG. 1B, the column 6 is a portion for supporting the boss of the flange 12 and is formed in a semicircular shape, but has a rotatable structure. The plate 7 is mounted directly on the boss of the flange 12 with a plurality of central bolts. 15 is a pillar and 25 is a lever.

The stud 30 is for connecting the impeller 38 to the shaft 39, as shown in FIG. 6B, and has a spherical body formed at the tip. FIG. 2 is a view for explaining the operation of the latch piece 29. The right half from the center line shows a state in which the lever 25 is raised. That is, the latch piece 29 engaged with the lower end flange portion of the lever 25 rotates rightward and its lower end is completely released from the head of the tip end of the stud 30.

On the other hand, the left half from the center line shows a state in which the latch piece 29 locks the head of the upper stud 30. That is, pressure is applied to the lower end protrusion of the latch piece 29 from the side, and the latch piece 29 is opposed to the turning moment of the latch piece 29.
Is stuck to the stud 30. As is apparent from FIG. 2, a lever 25 is fixed to the piston head 24, and the right half is raised and the left half is lowered to the lever 25 using the guide plate 26 at the lower end of the wall plate 14 as a guide.

FIG. 3 shows a state in which the lever 25 is bent at a right angle from the support 6 and the shaft is placed horizontally in FIG. That is, the handling tool of the present embodiment is suspended in the vertical direction by the wire rope 62, and the hose 32 and the hose joint 3 are suspended. Frame 4 and support 5,
6 are all standing upright.

The wall plate 15 fixed to the left flange 12 and the wall plate 14 fixed to the right flange 13 provided between the columns 5 and 6 shown in FIG. It turns at right angles with the movement, but locks the upper stud 30. The relative position of the lever 25 and the upper stud 30 remains unchanged while being locked by the application of air pressure. That is, the locked state of the circuits in the columns 5 and 6 remains unchanged because the boss of the flange 13 is always connected via the groove on the outside of the boss even if the boss of the flange 13 rotates into the lateral hole of the column.

Next, a system circuit for supplying pressurized air to the shaft handling tool for an internal pump according to the above embodiment will be described with reference to FIG. In FIG. 4, reference numeral 81 indicates a land-land boundary between the furnace and the inside of the furnace (reactor water). On the furnace, from the discharge side of the compressor 71, a valve 74, a filter 75, and an oil removal 7
6, the regulator 77, the oiler 78, and the switching valve 79 are sequentially connected. The safety valve 70 and the drain valve 72 are connected to the compressor 71. Three pressure relays 83 are provided.

The pressure relay 83 is connected to the valve 22 in the furnace via a control hose 84. Valve 22 is Euler
It is connected to a valve 82 branched from 78 via a control hose 84a. The switching valve 79 on the furnace and the switching valve 80 in the furnace are connected, and these switching valves 79 and 80 are connected to the handling tool 63 and the drive hose.
Connected via 85.

Next, the operation of the shaft handling tool according to the above embodiment will be described. At the time of the periodic inspection, the work is performed in the state of FIG. In the case of an internal pump, an impeller, a shaft, a diffuser, a stretch tube, and a diffuser wear ring are handled from the furnace upper side, and a storage rack, a temporary storage table, and the like are provided in a fuel pool.

When removing the impeller and the shaft, the joint between the impeller, the shaft and the motor section is separated in advance at the lower part of the furnace, and the sealing flange of the motor casing is attached. After the intrusion of water is prevented, the impeller and shaft are pulled up.

In preparation, the hoses are connected to the shaft handling tools, respectively, and the cylinders are pressurized, the piston is raised, and the latch pieces are opened. Subsequently, the terminal fitting of the wire of the hoist is screwed into the hanging stud. At this time, the spring at the tip of the sliding pin operates, and the pneumatic circuit in the frame is closed. The spring overcomes the weight of the shaft handle and helps maintain the circuit.

The refueling machine 48 is run, and is lowered from just above the internal pump 60 with the shaft handling tool attached. Lower the impeller and shaft along the guide rail provided on the outside of the shroud, and cover the head stud 30 of the internal pump with the cap 27 attached to the guide plate 26 at the tip of the shaft handling tool. 22 is ventilated, allowing the operation of the air cylinder.

Thereafter, a reverse pressure is applied to the air cylinder from the control panel on the refueling machine 48 to lower the lever, and the latch piece 29 is squeezed in conjunction therewith to grip the head of the upper stud 30. The contact piece on the piston head presses the stem of the valve on the guide to ventilate as shown in FIG. 1 (a), thereby gripping the impeller head.

Next, the wire rope of the auxiliary hoist is wound up. The spring 10 is subjected to a load applied to the impeller and the shaft, and the spring is quantitatively compressed. The slide pin 31 acts as a spindle against the frame to cut off the circuit of the frame.

Accordingly, the cylinder cannot be pressurized, and the lock between the impeller and the shaft is moved from the core to the fuel pool without loosening. Further, the impeller and the shaft can be pulled up onto the operation floor from the fuel pool, and the impeller and the shaft can be placed in a horizontal state.

In the present invention, a rail-shaped guide for an underwater remote tool is provided on the outside of the shroud. Roller equipment or the like that meshes with the guide is added to the handling tool according to the present invention. The control fluid may be used, and the control fluid has been described mainly on the pneumatic pressure.

[0060]

According to the present invention, workability in a narrow space under water at a high depth is poor, and work under bad conditions where visual confirmation is extremely difficult is facilitated, and stability is high. Further, when the impeller and the shaft are pulled out of the furnace water into the air of the operation professional on the furnace, there is an effect that the impeller and the shaft can be changed from the vertical state to the horizontal state.

Therefore, the disassembly / assembly of the impeller and the shaft can be reliably performed in a short time during the maintenance and inspection work of the internal pump, and the work can be performed safely.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view showing an embodiment of a shaft handling tool for an internal pump according to the present invention. (B) is (a)
Is a side view as viewed from the direction of arrows AA.

FIG. 2 is a longitudinal sectional view showing a partial side surface for explaining an operation state of a lever and a latch piece in FIG. 1 (a).

FIG. 3 is a side view showing a state in which a lever is bent at a right angle from a support in FIG. 1 (b).

FIG. 4 is a piping diagram showing an air pressurizing system path of the handling tool in FIG. 1 (a).

5A is a longitudinal sectional view schematically showing a boiling water reactor, and FIG. 5B is a longitudinal sectional view showing a state in which underwater work is performed in FIG.

6A is a longitudinal sectional view showing the internal pump in FIGS. 5A and 5B, and FIG. 6B is an elevation view showing the relationship between the impeller and the shaft in FIG. 5A.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stud for suspension, 2, 3 ... Hose joint, 4 ... Frame, 5, 6 ... Prop, 7 ... Side plate, 8 ... Guide plate, 9 ... Pin, 10 ... Large diameter spring, 11 ... Cap nut, 12 ,13
… Flange, 14,15… Wall plate, 16… Cylinder, 17… Small diameter spring, 18… Piston, 19… Stopper, 20… Tail cover,
21 ... press, 22 ... valve, 23 ... contact piece, 24 ... piston head, 25 ... lever, 26 ... guide plate, 27 ... cap, 28 ... pin, 29 ... latch piece, 30 ... top stud, 31 ... slide pin ,
32, 33 ... hose, 34 ... shroud, 34a ... water channel, 35 ... reactor pressure vessel, 36 ... casing, 37 ... wear ring, 38
... impeller, 39 ... shaft, 40 ... stub tube, 41 ...
Diffuser, 42 ... diffuser boss, 43 ... stretch tube, 44 ... tightening nut, 45 ... secondary seal, 46 ... motor, 47 ... stud, 48 ... refueling machine, 49 ... equipment pool,
50 ... Containment vessel, 60 ... Internal pump, 63 ... Shaft fitting, 70 ... Safety valve, 71 ... Compressor, 72 ... Drain valve, 73 ... Pressure gauge, 74 ... Valve, 79,80 ... Switching valve.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-333194 (JP, A) JP-A-5-188176 (JP, A) JP-A-64-54294 (JP, A) JP-A-63-1988 55392 (JP, A) JP-A-62-96895 (JP, A) JP-A-61-225693 (JP, A) JP-A-5-126982 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) G21C 15/243 520 G21C 19/02 F04D 7/08

Claims (1)

(57) [Claims] And 1. A post, a frame provided on the upper portion of the strut, a sliding pin provided slidably through the frame, and a spring for biasing the slide pin downward,
And suspending lifting studs that are attached to the upper portion of the sliding pin, and rotatably connected to the wall plate bent in the lower part of the strut, the wall plate
To a piston and cylinder da provided, and a spring for urging the piston there in the cylinder downward, the piston
A piston head attached below the piston shaft connected to the ton, a lever connected to the piston head,
A guide plate which is connected to the lower portion of the wall plate in sliding contact with the lever of the inner surface, is attached rotatably to the guide plate said lever
Open / close by the vertical movement of the child
A plurality of latch pieces that engages the city of upper stud, the full
The cylinder provided in the frame, strut, and wall plate
It consists of a flow path of the drive to pressurized fluid, on the sliding pin
A shaft handling device for an internal pump, wherein the passage for the pressurized fluid is shut off when the shaft is moved to the side .