CN215326509U - A structure that is used for AP1000 unit blasting valve to disintegrate and assemble - Google Patents

Abstract

The utility model discloses a structure for disassembling and assembling an explosion valve of an AP1000 unit, which is characterized by comprising a hoisting tool and a disassembling and assembling platform of a valve cover-piston-tensioning bolt assembly, wherein the hoisting tool comprises a support column and a guide column which are arranged on a valve body of the explosion valve; the disassembly and assembly platform comprises a fixed platform, the center of the fixed platform is in threaded connection with a rotating cylinder for installing the valve cover-piston-tensioning bolt assembly, the upper end of the rotating cylinder is fixedly connected with a rotating table, and the rotating table is connected with an extension handle; the tensioning bolt is connected with an expansion tool for limiting the relative rotation of the tensioning bolt and the piston.

Description

A structure that is used for AP1000 unit blasting valve to disintegrate and assemble

Technical Field

The utility model relates to a structure for disassembling and assembling a blasting valve of an AP1000 nuclear power unit, in particular to a structure for disassembling and assembling a 14-inch blasting valve of an AP1000 nuclear power unit.

Background

The 14-inch explosion valve of the AP1000 nuclear power unit is special in structure, and a key component, namely a tension bolt, is provided with a force weak point 1 which is made artificially, so that after an opening signal of the explosion valve is triggered, the tension bolt can be broken through impact force generated by detonation of explosives installed in a valve body of the explosion valve, and the effect of opening the valve is achieved. The middle position of the tension bolt is provided with 1 necking, and two ends of the tension bolt are in threaded structures and are screwed into threaded holes of the valve cover of the explosion valve and the piston respectively. In the process of disassembling the 14-inch blasting valve, the tension bolt is easy to damage and even break in 2 operation steps. The 14-inch explosion valve is positioned in a steam generator compartment of a nuclear island plant, the environment radiation dose rate of the room is high, the operation stage is a red area, the shutdown and overhaul stage is an orange area, and fig. 1 shows the internal structure diagram of the 14-inch explosion valve.

The first possible damage and breakage of the tie bolts is: the valve cover-piston-tie bolt assembly is lifted out of the valve cavity as a whole. The current industry practice of the step is as follows: finding 1 hoisting rooting point above the blasting valve, hanging a chain block, installing 2 hoisting rings on the valve cover, connecting with a hook of the chain block through a hoisting belt, and after removing a bolt of the valve cover, hoisting the valve cover-piston-tensioning bolt assembly out of the valve cavity by operating the chain block as shown in figure 2.

The second possible step of tension bolt damage and breakage is: the valve cap is unscrewed from the tension bolt-piston assembly. The weight of the valve cover of the 14-inch explosion valve reaches 564kg, when the valve cover is screwed out of the tension bolt-piston assembly, the valve cover-piston-tension bolt assembly is firstly placed on a fixed platform, the valve cover is hung by a chain block, the valve cover is rotated by an individual 1, the individual 2 tightens the chain block step by step simultaneously to avoid the weight of the valve cover from pressing on the tension bolt as much as possible, the individual 3 fixes the tension bolt by using an inner hexagon wrench through a hole at the bottom of the piston to prevent the tension bolt from rotating, and finally, the valve cover is separated from the tension bolt by 3 persons in a matching way.

The technical problems in the prior art are as follows:

1 st influencing factor: the middle position of the tension bolt is provided with 1 necking, and two ends of the tension bolt are in threaded structures and are screwed into threaded holes of the valve cover of the explosion valve and the piston respectively. The tension bolts are susceptible to damage and even breakage when subjected to radial shear and bending forces.

The 2 nd influencing factor: the 14-inch blasting valve of the AP1000 unit is arranged in a steam generator compartment of a nuclear island, a plurality of devices are arranged in a room, and a pipeline, a device, a cable and a support hanger are complicated and complicated above the blasting valve, so that the space is relatively narrow, and a proper hoisting root spot welding lifting lug is difficult to find.

Under the influence of the above 2 nd factor, when the "lifting the valve cover-piston-tie bolt assembly as a whole out of the valve chamber" operation is performed, it is difficult to set the lifting point directly above the explosion valve. Therefore, the method of directly hoisting the valve cover-piston-tensioning bolt assembly by the chain block can lead the piston of the assembly to be subjected to additional acting force in the horizontal direction, and on one hand, the acting force can lead the valve cover-piston-tensioning bolt assembly to be jammed when being drawn out, thereby causing the piston and the valve cavity to be scratched; on the other hand, this force is transmitted to the tensioning bolt, which can cause damage to the tensioning bolt.

When the operation of screwing the valve cover out of the tension bolt is executed, firstly, the valve cover-piston-tension bolt assembly is placed on a fixed platform, then the valve cover is hung by a chain block, the valve cover is rotated by the 1 st person, the chain block is gradually tightened by the 2 nd person simultaneously so as to prevent the weight of the valve cover from being pressed on the tension bolt as much as possible, and the tension bolt is fixed by the 3 rd person through a hole at the bottom of the piston by using an inner hexagon spanner so as to prevent the tension bolt from rotating. Because of the structural limitation of the chain block, the chain block can not be lifted at a constant speed during operation, and the chain block is lifted immediately. In addition, a person operating the chain block cannot determine that the weight of the valve cover is completely borne by the chain block by means of hand feeling. This kind of condition leads to rotatory and the in-process that promotes the valve gap, and the rocking that is difficult to control can appear in the valve gap, and practice proves even increase to 3 staff full-time rotatory and stable valve gap, also is difficult to avoid the valve gap to rock. Because the valve cover weighs a lot (564kg), the wobble has a very large risk of causing the tension bolt to be damaged or even broken. And increasing staff necessarily increases the collective radiation exposure dose of the workgroup.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that the tension bolt is easy to break due to technical defects in the prior art.

In order to solve the technical problems, the technical scheme of the utility model provides a structure for disassembling and assembling a blasting valve of an AP1000 unit, which is characterized by comprising a hoisting tool and a disassembling and assembling platform which are respectively used for hoisting and disassembling a valve cover-piston-tensioning bolt assembly, wherein the hoisting tool comprises a support column and a guide column which are arranged on a valve body of the blasting valve, a support nut and a locking nut are arranged on the support column, a horizontal cross beam is arranged between the support nut and the locking nut and used for installing a horizontal cross beam, an internal thread hole is formed in the middle of the horizontal cross beam and used for connecting a lifting bolt in a threaded manner, a universal lifting bolt is arranged at the lower part of the lifting bolt, and the universal lifting bolt is connected with the lifting bolt arranged on the valve cover of the blasting valve through a hoisting belt;

the disassembly and assembly platform comprises a fixed platform, the center of the fixed platform is in threaded connection with a rotating cylinder for installing the valve cover-piston-tensioning bolt assembly, the upper end of the rotating cylinder is fixedly connected with a rotating table, and the rotating table is connected with an extension handle; in operation, the assembled tensioning bolt expansion tool is used to fix the tensioning bolt and the piston relatively to prevent the tensioning bolt from rotating relative to the piston.

Wherein, the fixed platform is provided with a supporting leg.

Wherein, connect tie bolt the tight instrument of expanding includes connecting rod, expansion ring and thrust nut, and the connecting rod passes expansion ring and thrust nut in proper order, and the cooperation of the hexagonal head of tip and the tie bolt tip hexagonal hole of connecting rod makes thereby the expansion ring expand tightly with the round hole inner wall on the piston through rotatory thrust nut to realize tie bolt and piston relatively fixed.

The utility model has the advantages that:

the mounting support column and the horizontal beam of the valve body of the explosion valve are used as hoisting stress points of the valve cover-piston-tensioning bolt assembly, so that the problem that a root point is difficult to hoist in a factory building is solved.

The tensioning bolt and the piston are relatively fixed by using a skillful expanding tool.

The valve cover dismounting platform is designed to be in a synchronous rotating and lifting mode, the thread pitch of the lifting structure is designed to be the same as that of the tension bolt, and the function that the valve cover and the tension bolt can be separated without lifting and rotating the valve cover is achieved.

Drawings

FIG. 1 is a schematic diagram of the internal structure of a prior art 14-inch burst valve;

FIG. 2 is a schematic diagram of a prior art valve cover-piston-tie bolt assembly hoisted by a chain block;

fig. 3 is a part view of a horizontal beam provided in the present embodiment, wherein fig. 3a is a top view and fig. 3b is a side view;

fig. 4 is a diagram of a support column component provided in the present embodiment, wherein fig. 4a is a schematic view of one end, and fig. 4b is a schematic view of the other end;

FIG. 5 is a detail view of a guide post provided in the present embodiment;

fig. 6 is a schematic view of a lifting bolt provided in the present embodiment, in which fig. 6a is a left side schematic view, fig. 6b is a front sectional schematic view, and fig. 6c is a right side schematic view;

FIG. 7 is a schematic view of a support nut provided in the present embodiment, wherein FIG. 7a is a schematic front sectional view and FIG. 7b is a schematic right-side view;

fig. 8 is a part view of a lock nut provided in the present embodiment, in which fig. 8a is a front sectional view and fig. 8b is a right side view;

FIG. 9 is a schematic view of the bonnet-piston-tie bolt assembly lifting tool provided in this embodiment;

fig. 10 is a part view of a connecting rod (expansion tool) provided in the present embodiment, in which fig. 10a is a left side schematic view, fig. 10b is a front schematic view, and fig. 10c is a right side schematic view;

fig. 11 is a part view of the expansion ring (expansion tool) provided in the present embodiment, in which fig. 11a is a front view and fig. 11b is a right side view;

fig. 12 is a part view of a thrust nut (expansion tool) provided in the present embodiment, in which fig. 12a is a left side schematic view and fig. 12b is a front schematic view;

FIG. 13 is a fragmentary view of the tension bolt expansion tool assembly provided in the present embodiment;

fig. 14 is a part view of the rotary table provided in the present embodiment, in which fig. 14a is a front view and fig. 14b is a right side sectional view;

fig. 15 is a part view of a rotating cylinder provided in the present embodiment, in which fig. 15a is a left side schematic view and fig. 15b is a front sectional view;

fig. 16 is a part view of the fixed table provided in the present embodiment, in which fig. 16a is a front view schematically, and fig. 16b is a right side sectional view;

fig. 17 is an assembly view (front view) of the bonnet mounting/dismounting platform provided in the present embodiment;

fig. 18 is an assembly view (plan view) of the valve cover mounting and dismounting platform provided in the present embodiment;

fig. 19 is a schematic view illustrating the disassembly of the valve cover by the platform for disassembling and assembling the valve cover according to the present embodiment.

Detailed Description

In order to make the utility model more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

Examples

The structure that this embodiment provided is used for disassembling and assembling of AP1000 unit blast valve, including lifting device and dismouting platform, lifting device is used for carrying out "hang out valve gap-piston-tie bolt subassembly whole from the valve intracavity" operation, as shown in fig. 9, during the operation, no longer with the help of the hoist and mount root point, but install 4 support columns 1 and 2 guide posts 2 in the well flange threaded hole of valve body 11, then install support nut 5 on the support column 1, install horizontal beam 3 through support nut 5, horizontal beam 3 is locked through lock nut 6, the middle processing of horizontal beam 3 has the internal thread hole, mutually support with the external screw thread of lifting bolt 4. The lower part of the lifting bolt 4 is provided with a universal lifting bolt 8, and the universal lifting bolt 8 is connected with a lifting bolt 9 arranged on a valve cover 10 through a lifting belt 7. By rotating the lifting bolt 4, the valve cover-piston-tie bolt assembly can be lifted out of the valve cavity smoothly as a whole. Because the lifting bolt 4 is arranged at the center position right above the valve cover-piston-tensioning bolt assembly, the horizontal acting force on the assembly cannot be generated in the lifting process, and the situations that the piston 12 is jammed and the tensioning bolt 13 is damaged are avoided;

the dismounting platform is used for executing the operation of screwing the valve cover out of the tension bolt, as shown in fig. 19, the valve cover-piston-tension bolt assembly is already placed on the valve cover dismounting platform, the dismounting platform comprises a fixed platform 16, the fixed platform 16 is supported by a supporting leg 17, a rotating cylinder 15 is installed in the center of the fixed platform 16 in a threaded connection mode, a rotating table 14 is fixedly connected to the upper end of the rotating cylinder 15, the valve cover-piston-tension bolt assembly is installed in the rotating cylinder 15, and an extension handle 18 is connected to the rotating table for operation; as shown in fig. 17, the tensioning bolt expansion tool is composed of a connecting rod, an expansion ring and a thrust nut, the connecting rod sequentially penetrates through the expansion ring and the thrust nut, the end hexagonal head of the connecting rod is matched with the tensioning bolt end hexagonal hole, and the thrust nut is rotated to expand the expansion ring outwards and tightly expand the inner wall of the round hole in the piston, so that the tensioning bolt and the piston are relatively fixed. During operation, firstly, the assembled tensioning bolt expansion tool is used for fixing the tensioning bolt and the piston relatively, so that the tensioning bolt is prevented from rotating relative to the piston;

and then, the valve cover is pulled by using a chain block 19 through 2 lifting ring screws arranged on the surface of the valve cover, 1 worker holds the valve cover, and the 1 worker operates an extension handle 18 on the rotary table platform to rotate the rotary table platform so as to rotate and descend the rotary table platform. Because the thread pitch of the rotary table is the same as the thread pitch of the tension bolt, the chain block does not need to be operated in the whole process, the valve cover shaking caused by operating the chain block is avoided, and the tension bolt is prevented from being damaged. The method is stable, safe and efficient through practical operation verification, and the equipment is effectively protected from being damaged.

In addition, by using the operation method, at least 1 worker can be reduced, and the steam generator compartment with higher environmental radiation dose rate is beneficial to reducing the collective radiation exposure dose of the workers.

By using the 14-inch demolition tool and the overhaul process for the blasting valve of the set AP1000 unit, when two key overhaul steps of 'lifting the valve cover-piston-tensioning bolt assembly out of the valve cavity integrally' and 'screwing the valve cover out of the tensioning bolt' are executed, hoisting rooting in a factory building is avoided, and the design that a rotary table and the tensioning bolt are the same in thread pitch is ingeniously utilized, so that the problems of piston jamming, valve cover shaking and tensioning bolt damage caused by shearing force can be well avoided, the demolition work of the blasting valve is more reliable, safe and efficient, the number of workers can be effectively reduced, the construction period is shortened, and the collective radiation exposure dose of a working group is greatly reduced.

The tool set and the maintenance process can practically and effectively achieve the effects through field actual operation verification.

Claims (3)

1. A structure for disassembling and assembling an explosion valve of an AP1000 unit is characterized by comprising a hoisting tool and a disassembling and assembling platform which are respectively used for hoisting and disassembling a valve cover-piston-tensioning bolt assembly, wherein the hoisting tool comprises a support column and a guide column which are installed on a valve body of the explosion valve;

the disassembly and assembly platform comprises a fixed platform, the center of the fixed platform is in threaded connection with a rotating cylinder for installing the valve cover-piston-tensioning bolt assembly, the upper end of the rotating cylinder is fixedly connected with a rotating table, and the rotating table is connected with an extension handle; the tensioning bolt is connected with an expansion tool for limiting the relative rotation of the tensioning bolt and the piston.

2. The structure for disassembling and assembling the blasting valve of the AP1000 unit according to claim 1, wherein the fixed platform is provided with a supporting leg.

3. The structure for disassembling and assembling the blasting valve of the AP1000 train as claimed in claim 1, wherein the expansion tool for connecting the tension bolt includes a connecting rod, an expansion ring and a thrust nut, the connecting rod sequentially passes through the expansion ring and the thrust nut, a hexagonal head at an end of the connecting rod is engaged with a hexagonal hole at an end of the tension bolt, and the expansion ring is expanded outward by rotating the thrust nut to expand against an inner wall of the circular hole on the piston, thereby relatively fixing the tension bolt and the piston.

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