CN110077949A - A kind of horizontal high-pressure stop valve dismantling device - Google Patents

Abstract

The invention discloses a horizontal high-pressure main steam valve disassembly tool, which includes a first suspension ring fixedly arranged on the top of the side wall of the main steam valve cover. A balance hoisting structure is provided to balance the overall weight of the main steam valve to ensure that the main steam valve core is in a horizontal state during the hoisting process, thereby facilitating the disassembly of the main steam valve. The second lifting ring for lifting the valve. The present invention is manufactured according to the center of gravity characteristics of the high-pressure main steam valve spool at the maintenance site of the large-scale steam turbine generator set and the actual space of the site, and can balance the series main The center of gravity of the steam valve spool maintains the level of hoisting the main steam valve spool, which avoids the difficulty of disassembly and assembly caused by the inconsistency between the lifting point and the center of gravity of the main steam valve spool, which causes the alloy bolt hole to be skewed.

Description

A horizontal high-pressure main steam valve disassembly tool

technical field

The invention relates to the technical field of maintenance of large steam turbine generator sets, in particular to a disassembly tool for a horizontal high-pressure main steam valve.

Background technique

Large turbogenerator sets are generally equipped with two symmetrically arranged high-pressure main steam valves, which are the first valves for high-temperature and high-pressure steam to enter the steam turbine, and most of them are operated in a horizontal position. The main steam valve includes a main steam valve cover, a main steam valve core and a main steam valve stem connecting sleeve. The valve core of the main steam valve is connected with the valve body of the steam chamber by a plurality of alloy bolts, and the valve body of the steam chamber and the steam chamber are cast as one. The high-pressure main steam valve is the main component of the steam turbine protection system. All shutdown protection of the steam turbine is finally realized by closing the main steam valve and the regulating steam valve. Therefore, the main steam valve must be disassembled and overhauled every time the unit is overhauled.

In the actual removal process of the main steam valve spool, to remove the main steam valve spool, the main steam valve automatic shut-off device must be removed first, the high and low pressure valve stem leakage flanges should be loosened, and then the high pressure connecting bolts should be Caps are all removed. At this time, the gantry crane is used to hang the lifting ring on the valve cover of the main steam valve, and three jacking wires are used to exert force evenly, so that there is a gap between the main steam valve core and the valve body of the steam chamber, and the crane is driven while tightening the jacking wires.

Due to the special arrangement and structure of the main steam valve, the gap between the alloy bolt hole (that is, the bolt hole of the main steam valve bonnet) and the thread of the alloy bolt is small, and the main steam valve bonnet is very thick, so it is difficult to maintain the gap during the removal process If the alloy bolts are uniform, it is easy to cause the alloy bolts and the alloy bolt holes to suffocate, which is time-consuming and labor-intensive. It is also easy to cause the thread of the alloy bolt to be scrapped or the gasket to be biased and damaged. The damaged alloy bolt can only be removed and a new one installed. Taking a 600MW supercritical unit as an example, each unit is equipped with two high-pressure main steam valves, the main steam inlet parameters are pressure 24.2MPa, temperature 538°C, and each main steam valve cover has 16 pieces of M72 material For R26 alloy bolts, the price of each alloy bolt is about 40,000 to 50,000 yuan, and the scrapping of alloy bolts has brought undue economic losses.

After removing the main steam valve spool, when hanging it with a gantry crane, it will be found that due to the structure of the main steam valve, the main steam valve spool is not in a horizontal state, as shown in Figure 2. For this reason, during the disassembly and assembly of the main steam valve, the wire rope and guide chain are used to adjust, as shown in Figure 3, the level cannot be accurately grasped at all in this process, which is the root cause of time-consuming and labor-intensive and strained alloy bolt threads.

SUMMARY OF THE INVENTION

The technical problem to be solved in the present invention is to provide a horizontal high-pressure main steam valve disassembly tool to solve the problem that the existing main steam valve core is easy to cause damage to the alloy bolts during disassembly and assembly, which will bring economic losses and time-consuming In order to reduce the difficulty of disassembly and assembly, balance the center of gravity of the main steam valve, make the disassembly and assembly of the high-pressure main steam valve more convenient, and ensure that the alloy bolts will not be damaged during the disassembly process.

In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

A horizontal high-pressure main steam valve disassembly tool, including a first lifting ring fixedly arranged on the top of the side wall of the main steam valve cover, and one end of the main steam valve cover not provided with the main steam valve core is connected with a The overall weight of the main steam valve is a balanced hoisting structure to ensure that the main steam valve core is in a horizontal state during the hoisting process, which facilitates the disassembly of the main steam valve. Second ring.

To further optimize the technical solution, the balance hoisting structure includes a flange connected to the main steam valve bonnet through connecting bolts, a hollow steel pipe fixedly connected to the flange and allowing the connecting sleeve of the main steam valve stem to pass through, and the One end of the hollow steel pipe is used to balance the overall weight of the main steam valve to ensure the hoisting of the main balance plate at the center of gravity, and the second lifting ring is fixedly arranged on the top of the main balance plate.

To further optimize the technical solution, the side wall of the main balance plate is provided with fine-tuning balance weights for finely adjusting the weight of the main balance plate through screws.

To further optimize the technical solution, the inner diameter of the hollow steel pipe is greater than the outer diameter of the connecting sleeve of the main steam valve stem.

To further optimize the technical solution, the main balance plate is thick steel plate or cast iron.

To further optimize the technical solution, the outer diameter of the main balance plate is smaller than or equal to the outer diameter of the main steam valve cover.

To further optimize the technical solution, a level detection mechanism for detecting whether the balance hoisting structure and the main steam valve are in a horizontal state is installed horizontally above the balance hoisting structure to achieve the purpose of precise balanced hoisting of the main steam valve.

To further optimize the technical solution, the level detection mechanism includes a leveler fixing plate fixedly arranged above the hollow steel pipe with the top end surface in a horizontal state, and a leveler fixed horizontally on the top end surface of the leveler fixing plate.

To further optimize the technical solution, the length of the balance hoisting structure is smaller than the difference between the distance between the main steam valve cover and the low-pressure cylinder and the length of the main steam valve spool.

Due to the adoption of the above technical solutions, the technological progress achieved by the present invention is as follows.

The present invention is manufactured according to the center of gravity characteristics of the high-pressure main steam valve spool at the maintenance site of the large-scale steam turbine generator set and the actual space of the site, and can balance the series main The center of gravity of the steam valve spool maintains the level of hoisting the main steam valve spool, avoiding the problem of disassembly and assembly difficulties caused by the inconsistency between the lifting point and the center of gravity of the main steam valve spool, and avoiding the extremely expensive high temperature , High-pressure alloy bolt thread damage, save a lot of maintenance man-hours and maintenance costs, improve the quality of maintenance, and eliminate the high-temperature and high-pressure steam leakage caused by seal failure or insufficient tightening force caused by high-pressure alloy bolt thread damage Potential safety hazards have been realized, and multiple harvests of safety benefits, economic benefits, and quality benefits have been achieved.

The balance hoisting structure of the present invention is fixedly connected with the main steam valve bonnet, and the top of the balance hoisting structure is provided with a second hoisting ring, the first hoisting ring and the second hoisting ring can be hoisted simultaneously by the gantry driving, and the weight of the balancing hoisting structure can be adjusted according to It depends on the actual weight of the main steam valve, which can effectively ensure that the main steam valve can be in a horizontal state when the main steam valve is lifted, thereby avoiding damage to the thread of the alloy bolt and flattening of the sealing gasket when the alloy bolt is disassembled. damage situation.

The setting of the fine-tuning balance weight in the present invention can play a role in micro-adjusting the weight of the main balance plate, thereby ensuring that the main steam valve can be in a horizontal state when it is hoisted.

The level detection mechanism installed horizontally above the balance hoisting structure of the present invention can detect whether the balance hoisting structure and the main steam valve are in a horizontal state, so as to achieve the purpose of precise balance hoisting of the main steam valve, and facilitate the adjustment and replacement of fine-tuning balance blocks of different weights .

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation after removing the main steam valve spool in the prior art;

Fig. 3 is a schematic diagram of the structure adjusted by the steel wire rope and the guide chain during the disassembly and assembly of the main steam valve.

Among them: 1. Main steam valve stem connection sleeve, 2. Screws, 3. Fine-tuning balance block, 4. Main balance plate, 5. First lifting ring, 6. Hollow steel pipe, 7. Connecting bolts, 8. Flange plate, 9. Alloy bolt hole, 10. Second lifting ring, 11. Sealing gasket, 12. Main steam valve core, 13. Fillet weld, 14. Low pressure cylinder, 15. Main steam valve cover, 16. Fixing leveler Plate, 17, leveler, 18, steam chamber valve body.

Detailed ways

The present invention will be further described in detail in conjunction with specific inventions below.

A horizontal high-pressure main steam valve disassembly tool, as shown in FIG. 1 , includes a first lifting ring 5 , a balanced lifting structure and a second lifting ring 10 .

The first suspension ring 5 is fixedly arranged on the top end of the side wall of the main steam valve cover 15 . The second lifting ring 10 is arranged on the top of the balance lifting structure, and cooperates with the first lifting ring 5 to lift the main steam valve.

The balance hoisting structure is connected to the end of the main steam valve bonnet 15 without the main steam valve core 12, which is used to balance the overall weight of the main steam valve to ensure that the main steam valve core 12 is in a horizontal state during the hoisting process, thereby facilitating Disassemble the main steam valve.

The balance hoisting structure includes a flange plate 8 , a hollow steel pipe 6 and a main balance plate 4 .

The flange 8 is connected with the main steam valve bonnet 15 through connecting bolts 7 . Before connecting the flange 8, the connecting bolt 7 is used to connect the main steam valve automatic closer and the main steam valve, and use the position of the connecting bolt 7 to process a suitable flange 8.

The hollow steel pipe 6 is fixedly connected with the flange 8, and the hollow steel pipe 6 is welded at the center of the flange 8. The inner diameter of the hollow steel pipe 6 is larger than the outer diameter of the main steam valve stem connecting sleeve 1. Specifically, the inner diameter of the hollow steel pipe 6 is slightly It is larger than the outer diameter of the connecting sleeve 1 of the valve stem of the main steam valve, so that the connecting sleeve 1 of the valve stem of the main steam valve passes through.

The main balance plate 4 is arranged at one end of the hollow steel pipe 6, and is used to balance the overall weight of the main steam valve to ensure that the hoisting center of gravity is between the valve cover 15 of the main steam valve and the main balance plate 4, and the weight of the main balance plate 4 is sufficient to lift the first The first suspension ring 5 and the second suspension ring 10 are determined by the horizontal state of the main steam valve spool 12. Specifically, welding is performed between the main balance plate 4 and the hollow steel pipe 6 . The main balance disc 4 is thick steel plate or cast iron. The outer diameter of the main balance disc 4 is less than or equal to the outer diameter of the main steam valve cover 15 . The second suspension ring 10 is fixedly arranged on the top of the main balance plate 4 .

Fillet welds 13 are provided between the main balance plate 4 and the hollow steel pipe 6 and between the hollow steel pipe 6 and the flange 8 .

In order to further ensure that the main steam valve spool 12 is in a horizontal state during the hoisting process, a fine-tuning balance block 3 is provided on the side wall of the main balance plate 4 through screws 2, and the fine-adjustment balance block 3 is used to finely adjust the position of the main balance plate 4. Weight, the overall weight of the main balance plate 4 and the fine-tuning balance weight 3 can be adjusted by changing the fine-tuning balance weight 3 of different weights. The weight of the fine-tuning balance weight 3 can be configured and numbered according to the actual conditions of different main steam valves of the power plant.

In order to detect whether the balance hoisting structure and the main steam valve are in a horizontal state, to achieve the purpose of precise balance hoisting of the main steam valve, and to facilitate the adjustment and replacement of the fine-tuning balance weight 3 of different weights, the present invention horizontally arranges a level bar above the balance hoisting structure. testing facility. The level detection mechanism includes a leveler fixing plate 16 and a leveler 17 . The leveler fixing plate 16 is fixedly arranged above the hollow steel pipe 6 , and the top end surface is in a horizontal state, and the leveler 17 is horizontally fixedly arranged on the top end surface of the leveler fixing plate 16 . In addition, the leveler fixing plate 16 and the leveler 17 can also be arranged at other positions.

The leveler 17 in the present invention is a cylindrical leveler, and the inside is provided with balance air bubbles. By confirming whether the air bubbles in the leveler 17 are in the middle, it is determined whether the balance hoisting structure and the main steam valve are in a horizontal position. If the air bubble in the leveler 17 is in the middle, it means that the balance hoisting structure and the main steam valve are in a horizontal state; On the right side, that is, the side that is biased towards the main steam valve, it is necessary to increase the weight of the balance hoisting structure.

The present invention is carrying out the method for dismounting of horizontal high-pressure main steam valve as follows.

The first step is to remove the main steam valve automatic closer, and make the flange plate 8 of the main steam valve disassembly tool according to the position and size of the connecting bolt 7 of the main steam valve automatic closer, and the size of the flange plate 8 is according to the position and size of the connecting bolt 7 and size depend.

The second step is to measure the outer diameter of the main steam valve stem connecting sleeve 1, select a hollow steel pipe 6 with a suitable inner diameter, put it on the main steam valve stem connecting sleeve 1, and weld and fix it with the flange 8.

The third step is to weld the main balance plate 4 at one end of the hollow steel pipe 6, and the weight of the main balance plate 4 is determined by lifting the first lifting ring 5 and the second lifting ring 10 after the main steam valve spool 12 is horizontal.

The fourth step is to install the fine-tuning balance weight 3 on the main balance plate 4 through the screw 2. The fine-tuning balance weight 3 can be configured and numbered according to the actual conditions of different main steam valves of different units in the power plant.

In the fifth step, the length of the disassembly and assembly tool for the main steam valve is made according to the actual space on site, and it is required that the surrounding equipment and facilities, such as the low-pressure cylinder 14, cannot be touched during the disassembly and assembly of the main steam valve spool 12. The length of the balanced hoisting structure is set as L, the distance between the main steam valve bonnet 15 and the low pressure cylinder 14 is L1, and the length of the main steam valve spool 12 is L2. The length of the balance hoisting structure is less than the difference between the distance between the main steam valve bonnet 15 and the low pressure cylinder 14 and the length of the main steam valve spool 12, ie L<L1-L2.

The sixth step is to simultaneously lift the main steam valve and the main steam valve disassembly tool by using the gantry crane. When lifting, it can ensure that the main steam valve is in a horizontal position, so that the alloy bolts can be easily removed from the alloy bolt holes 9 on the main steam valve bonnet 15. It can be disassembled from above, and the disassembly process will not cause damage to the alloy bolts, nor will it cause damage to the pressure deviation of the sealing gasket 11.

Claims (9)

1. A horizontal high-pressure main steam valve dismounting tool, comprising the first suspension ring (5) fixedly arranged on the top of the side wall of the main steam valve cover (15), characterized in that: the main steam valve cover (15) ) One end without main steam valve spool (12) is connected with a balance hoisting structure for balancing the overall weight of the main steam valve to ensure that the main steam valve spool (12) is in a horizontal state during hoisting, thereby facilitating the disassembly of the main steam valve , the top of the balance hoisting structure is provided with a second hoisting ring (10) that cooperates with the first hoisting ring (5) to hoist the main steam valve. 2. A horizontal high-pressure main steam valve dismounting tool according to claim 1, characterized in that: the balance hoisting structure includes a method for connecting the main steam valve bonnet (15) through connecting bolts (7). The blue plate (8), the hollow steel pipe (6) fixedly connected with the flange plate (8) and allowing the main steam valve stem connecting sleeve (1) to pass through, and the hollow steel pipe (6) arranged at one end of the hollow steel pipe (6) for balancing the main steam valve The overall weight is to ensure the hoisting of the main balance plate (4) at the position of the center of gravity, and the second suspension ring (10) is fixedly arranged on the top of the main balance plate (4). 3. A horizontal high-pressure main steam valve disassembly tool according to claim 2, characterized in that: the side wall of the main balance plate (4) is provided with screws (2) for micro-adjustment of the main balance The fine-tuning balance weight (3) of dish (4) weight. 4. A horizontal high-pressure main steam valve disassembly tool according to claim 2, characterized in that: the inner diameter of the hollow steel pipe (6) is larger than the outer diameter of the main steam valve stem connecting sleeve (1). 5. A horizontal high-pressure main steam valve disassembly tool according to claim 2, characterized in that: the main balance plate (4) is a thick steel plate or cast iron. 6. A horizontal high-pressure main steam valve disassembly tool according to claim 2, characterized in that: the outer diameter of the main balance plate (4) is smaller than or equal to the outer diameter of the main steam valve cover (15). 7. A horizontal high-pressure main steam valve dismounting tool according to claim 2, characterized in that: the top of the balance hoisting structure is horizontally provided for detecting whether the balance hoisting structure and the main steam valve are in a horizontal state to achieve The horizontal detection mechanism for the purpose of precise balance lifting of the main steam valve. 8. A horizontal high-pressure main steam valve dismounting tool according to claim 7, characterized in that: the level detection mechanism includes a leveler fixedly arranged above the hollow steel pipe (6) and the top surface is horizontal. Plate (16) and the leveler (17) that is horizontally fixedly arranged on the top end surface of the leveler fixing plate (16). 9. A horizontal high-pressure main steam valve dismounting tool according to claim 1, characterized in that: the length of the balance hoisting structure is less than the distance between the main steam valve cover (15) and the low-pressure cylinder (14). The difference between the distance and the length of the main steam valve spool (12).