Double-cover steam generator inclined manhole closing tool

Abstract

The present invention belongs to the field of nuclear power technology, and particularly relates to a bevel manhole closing tool for a double-cover steam generator. It includes a centering device, a fixing device, and a conversion fixing device; the centering device is used independently to align the inner manhole cover with the manhole axis and then remove it. The fixing device and the conversion fixing device are used in cooperation. First, the fixing device is used to fix the inner manhole cover, and then the conversion fixing device is used to ensure the removal of the fixing device and the correct reinstallation of the outer manhole cover. Its beneficial effects are as follows: (1) For the centering of the inner manhole cover, during the lifting process of the inner manhole cover, fine adjustment of the position of the inner manhole cover can be achieved to lift the inner manhole cover to the designated position; (2) For the fixing of the inner manhole cover, after the inner manhole cover is lifted to the designated position, the left and right clamping plates and the transition studs are used to fix the inner manhole cover.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power, and particularly relates to a closing tool for the inclined manhole of a double - cover steam generator. Background Art

[0002] The secondary side of the steam generator in a nuclear power plant includes a manhole structure. The manhole structure includes an inner manhole cover and an outer manhole cover. The inner manhole cover is supported by a rotating arm and can rotate around the rotating arm. The rotating arm is fixed on the inner surface of the head and can rotate around a fixed axis. When closing the manhole, by swinging the rotating arm, the inner manhole cover is rotated to the manhole position, and then by swinging the inner manhole cover, the inner manhole cover is aligned with the manhole. Through the outer manhole cover and fastening bolts, the inner manhole cover can be lifted and closely fitted with the manhole seat. However, the rotating shaft and the inner manhole cover in the manhole structure are long - term inside the steam generator. During the operation of the equipment, steam, water and impurities enter the rotating mechanism of the inner manhole cover and the rotating arm, forming rust, which makes it difficult for the inner manhole cover and the rotating arm to move. When opening the manhole, additional force is required to forcibly move the inner manhole cover and the rotating arm. This additional force causes the rotating mechanism of the inner manhole cover and the rotating shaft to become loose, and the inner manhole cover cannot be aligned with the manhole, so that the inner manhole cover cannot be lifted to the specified position through the outer manhole cover and manhole bolts, and the manhole cannot be closed smoothly. Summary of the Invention

[0003] Mainly aiming at the above - mentioned problems, the purpose of the present invention is to provide a closing tool for the inclined manhole of a double - cover steam generator, which helps to align the inner manhole cover and lift it to the specified position and keep it fixed. When installing the outer manhole cover, the manhole closing tool can ensure that the inner manhole cover remains stationary, and then the manhole bolts can be smoothly installed to complete the closing of the manhole.

[0004] The technical solution of the present invention is as follows: A closing tool for the inclined manhole of a double - cover steam generator includes an alignment device, a fixing device and a conversion fixing device; the alignment device is used independently and is removed after aligning the inner manhole cover with the manhole coaxially. The fixing device and the conversion fixing device are used in cooperation. First, the fixing device is used to fix the inner manhole cover, and then the conversion fixing device is used to ensure the removal of the fixing device and the correct reinstallation of the outer manhole cover.

[0005] The alignment device includes a load - bearing plate assembly, an adjustment plate assembly, a first universal handle assembly and a second universal handle assembly. Two rows of card slots are arranged on the adjustment plate assembly. The first universal handle assembly and the second universal handle assembly take the card slots as nodes and cooperate with the load - bearing plate assembly to adjust the position of the inner manhole cover.

[0006] The first universal handle assembly is a universal handle with a pin.

[0007] The second universal handle assembly is a universal handle without a pin.

[0008] The fixing device comprises a transition bolt, a left clamping plate set and a right clamping plate set. The transition bolt is screwed into the inner cover of the manhole. The left clamping plate set and the right clamping plate set clamp the transition bolt. The left clamping plate set and the right clamping plate set are supported on the manhole cover.

[0009] There are 4 transition bolts.

[0010] The conversion fixing device comprises a transition bracket, a replacement bolt and a replacement nut. The replacement bolt is screwed into the manhole inner cover and cooperates with the transition bracket and the replacement nut to fix the manhole inner cover.

[0011] The number of replacement bolts is 4.

[0012] The number of replacement nuts is 4.

[0013] The beneficial effects of the present invention are:

[0014] (1) The centering of the manhole inner cover can achieve fine adjustment of the position of the manhole inner cover during the lifting process, so that the manhole inner cover can be lifted to the specified position;

[0015] (2) Fixing of the inner cover of the manhole. After the inner cover of the manhole is lifted to the specified position, the inner cover of the manhole is fixed by using the left and right clamps and transition studs;

[0016] (3) When installing the outer manhole cover, the inner manhole cover remains stationary and is fixed by using transition brackets, replacement studs and nuts. In this way, when the outer manhole cover is installed and the left and right clamps are removed, the inner manhole cover can still remain fixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the manhole structure on the secondary side of the steam generator;

[0018] Figure 2 This is a schematic diagram of the double-cover steam generator inclined manhole closing tool provided by the present invention.

[0019] Figure 3 It is a schematic diagram of the structure of the centering device;

[0020] Figure 4 Schematic diagram of the fixture and conversion fixture.

[0021] In the figure: 1 manhole outer cover, 2 manhole inner cover, 3 manhole nuts, 4 manhole studs, 5 load-bearing plate assembly, 6 adjustment plate assembly, 7 first universal handle assembly, 8 second universal handle assembly, 9 left clamping plate kit, 10 right clamping plate kit, 11 transition bolts, 12 transition bracket, 13 replacement bolts, 14 replacement nuts. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] As Figure 2 shown, the inclined manhole closing tool for the double-cover steam generator provided by the present invention includes a centering device, a fixing device, and a conversion fixing device.

[0024] The centering device includes a bearing plate assembly 5, an adjusting plate assembly 6, a first universal handle assembly 7, and a second universal handle assembly 8. Among them, the first universal handle assembly 7 is a universal handle with a pin, the second universal handle assembly 8 is a universal handle without a pin, and two rows of card slots are provided on the adjusting plate assembly 6. The first universal handle assembly 7 and the second universal handle assembly 8 take the card slots as nodes and cooperate with the bearing plate assembly 5 to adjust the position of the inner manhole cover.

[0025] The fixing device includes a transition bolt 11, a left card plate kit 9, and a right card plate kit 10. The transition bolt 11 is screwed into the inner manhole cover, the left card plate kit 9 and the right card plate kit 10 clamp the transition bolt 11, and the left card plate kit 9 and the right card plate kit 10 support on the manhole cover to realize the fixation of the inner manhole cover.

[0026] The conversion fixing device includes a transition bracket 12, a replacement bolt 13, and a replacement nut 14. The replacement bolt 13 is screwed into the inner manhole cover 2, and cooperates with the transition bracket 12 and the replacement nut 13 to fix the inner manhole cover 2, which is convenient for the removal of the fixing device and the positioning of the outer manhole cover.

[0027] Among them, the centering device is used independently and removed after aligning the inner cover with the manhole coaxially. The fixing device and the conversion fixing device are used in cooperation. First, the fixing device is used to fix the inner cover, and then the conversion fixing device is used to ensure the removal of the fixing device and the correct reinstallation of the outer manhole cover.

[0028] The usage method of the centering special tool is as follows:

[0029] (1) Use a chain block to lift the inner cover plate close to the inner surface of the manhole, and insert the bearing plate column into the screw hole of the inner cover.

[0030] (2) After lifting and unscrewing the support block on the adjusting plate, place the adjusting plate into the manhole. After the adjusting plate is placed, screw the support block back to the support position.

[0031] (3) Insert the pin on the universal handle with a pin into the lifting lug hole on the inner cover, and insert the universal handle without a pin into the round hole of the bearing plate. Adjust the gap slightly by moving the handle according to the gap condition around the inner cover. Until the inner cover is aligned with the manhole. Lift the chain block and pull the inner cover plate into the manhole.

[0032] The usage process of the present invention is as follows:

[0033] (1) Hang the hook of the chain block on the lifting lug in the middle of the inner cover, keep the hook tightened all the time, and screw in 4 transition bolts.

[0034] (2) Insert the left and right clamping plates against the transition bolts (note that the large head of the clamping plate is at the lower position and the nylon surface is against the housing). Insert the left and right clamping plate mating supports (nylon surface against the housing), and confirm that the pins are inserted for positioning.

[0035] (3) After tightening the transition bolts, remove the hook of the chain block. Lift the outer cover with the gasket installed and slide it down along the four transition bolts and land on the clamping plates, then remove the hook of the hoist.

[0036] (4) Screw in the four replacement bolts, place the transition bracket and tighten the four replacement nuts.

[0037] (5) Loosen the four transition bolts, lift the outer cover plate away from the left and right clamping plates (note to prevent the outer cover plate from hitting the transition bracket). First, lift the left and right clamping plate mating supports upward, remove the pins and then pull them out. Then pull the left and right clamping plates out to the left and right.

[0038] (6) After confirming that the gasket of the upper cover is not detached, slowly lower the upper cover plate into the manhole. Remove the hook of the chain block and screw in two equipment bolts and nuts.

[0039] (7) Remove the remaining tool parts.

[0040] (8) Install all the equipment bolts, washers and nuts, and tighten them according to the original tightening sequence and torque.

[0041] In order to smoothly close the manhole of the secondary side of the steam generator, the manhole closing tool provided by the present invention, through the inner manhole cover and the manhole seat, lifts the inner manhole cover to a specified position and then keeps the inner manhole cover fixed. When installing the outer manhole cover, the manhole closing tool still keeps the inner manhole cover fixed, smoothly installs and tightens the bolts, closes the manhole, greatly improves the efficiency of the manhole closing process, reduces the manhole closing time, and wins precious time for the overhaul.

[0042] The operation process of the present invention is as follows:

[0043] When closing the manhole, move the inner manhole cover near the manhole, install the load-bearing plate assembly 5 into the rightmost bolt hole of the inner manhole cover, install the alignment plate assembly 6 on the manhole seat, insert the pin on the first universal handle assembly 7 into the lifting lug hole on the inner manhole cover 2, insert the second universal handle assembly 8 into the round hole of the load-bearing plate assembly 5, lift the inner manhole cover 2, and move the first universal handle assembly 7 and the second universal handle assembly 8 according to the gap situation between the inner manhole cover 2 and the periphery of the manhole seat to make a slight adjustment of the gap until the inner manhole cover 2 is aligned with the manhole, and then lift the inner manhole cover 2 into the manhole.

[0044] After the inner manhole cover 2 is lifted into the manhole, install the transition bolt 11 on the inner manhole cover 2, insert the left clamping plate kit 9 and the right clamping plate kit 10 against the transition bolt 11, and tighten the transition bolt 11 to fix the inner manhole cover 2.

[0045] Install the manhole outer cover 1 onto the manhole seat. The manhole outer cover 1 passes through the transition bolt 11 and presses on the left clamping plate kit 9 and the right clamping plate kit 10. Screw the replacement bolt 13 into the bolt hole of the manhole inner cover 2. The replacement bolt 13 simultaneously passes through the through hole of the manhole outer cover 1. Install the transition bracket 12 onto the manhole seat. At the same time, insert the replacement bolt 13 into the through hole of the manhole outer cover 1. Install the replacement nut 14 on the replacement bolt 13 to fasten the transition bracket 12 and the manhole inner cover 2. Loosen the transition bolt 11, lift the manhole outer cover 1 away from the left clamping plate kit 9 and the right clamping plate kit 10, remove the left clamping plate kit 9 and the right clamping plate kit 10, and slowly lower the manhole outer cover 1 into the manhole.

[0046] Install the manhole studs 4 and manhole nuts 3 at the leftmost and rightmost positions of the manhole to keep the manhole inner cover 2 stationary. Remove the remaining tools, install the other manhole studs 4 and manhole nuts 3, and the manhole closing operation is completed.

Claims

1. Double-cover steam generator inclined manhole closing tool, Characterized in that: It includes a centering device, a fixing device and a conversion fixing device; the centering device is used independently to align the inner manhole cover with the manhole coaxially and then remove it. The fixing device and the conversion fixing device are used in cooperation. First, the fixing device is used to fix the inner manhole cover, and then the conversion fixing device is used to ensure the removal of the fixing device and the correct reinstallation of the outer manhole cover.

2. The double-cover steam generator inclined manhole closing tool according to claim 1, Characterized in that: The centering device includes a bearing plate assembly, an adjusting plate assembly, a first universal handle assembly and a second universal handle assembly. Two rows of card slots are provided on the adjusting plate assembly. The first universal handle assembly and the second universal handle assembly use the card slots as nodes and cooperate with the bearing plate assembly to adjust the position of the inner manhole cover.

3. The double-cover steam generator inclined manhole closing tool according to claim 2, Characterized in that: The first universal handle assembly is a universal handle with a pin.

4. The double-cover steam generator inclined manhole closing tool according to claim 2, Characterized in that: The second universal handle assembly is a universal handle without a pin.

5. The double-cover steam generator inclined manhole closing tool according to claim 1, Characterized in that: The fixing device includes a transition bolt, a left card plate kit and a right card plate kit. The transition bolt is screwed into the inner manhole cover. The left card plate kit and the right card plate kit clamp the transition bolt, and the left card plate kit and the right card plate kit support on the manhole cover.

6. The double-cover steam generator inclined manhole closing tool according to claim 5, Characterized in that: There are 4 transition bolts.

7. The double-cover steam generator inclined manhole closing tool according to claim 1, Characterized in that: The conversion fixing device includes a transition bracket, replacement bolts and replacement nuts. The replacement bolts are screwed into the inner manhole cover and cooperate with the transition bracket and the replacement nuts to fix the inner manhole cover.

8. The double-cover steam generator inclined manhole closing tool according to claim 7, Characterized in that: There are 4 replacement bolts.

9. The double-cover steam generator inclined manhole closing tool according to claim 7, Characterized in that: There are 4 replacement nuts.

10. The double-cover steam generator inclined manhole closing tool according to claim 2, Characterized in that: The conversion fixing device includes a transition bracket, replacement bolts and replacement nuts. The replacement bolts are screwed into the inner manhole cover and cooperate with the transition bracket and the replacement nuts to fix the inner manhole cover.

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