Grinding device for main throttle valve of steam turbine

Abstract

The utility model discloses a steam turbine main throttle valve grinding device which comprises a machine frame, a power machine, a transmission mechanism, a cam, a transmission shaft, a driven piece, a guide rod, a limiting block and a hanging piece, the machine frame is arranged above a valve seat of a main throttle valve, the power machine drives the cam arranged in the machine frame to rotate through the transmission mechanism, and a rotating shaft of the cam is connected with the machine frame; the driven part is located in the rack, the transmission shaft is rotationally connected with the driven part, the transmission shaft keeps in linear contact with the curve profile surface of the cam in the rotation process of the cam so as to push the driven part to reciprocate in the vertical direction, and the curve profile surface comprises an ascending section, a first stopping section, a descending section and a second stopping section; the upper end of the driven piece is connected with a limiting block above the rack through a guide rod, the lower end of the driven piece is connected with the valve rod through a hanging piece, and the driven piece, a main valve core connected with the valve rod and a valve core sealing ring of the valve seat are coaxially arranged. The utility model solves the problems that the efficiency is low and the original sealing performance is difficult to guarantee in the existing manual grinding of the main throttle valve of the steam turbine.

Description

TECHNICAL FIELD

[0001] The utility model relates to the valve core sealing technical field of high temperature and high pressure steam valve, especially a steam turbine main steam valve grinding device. BACKGROUND

[0002] In the process of high temperature steam being transported to the steam turbine through the pipeline, the steam and the iron material in the pipeline and the steam turbine components can have oxidation reaction, the reaction can gradually accumulate to form the oxide skin on the valve core sealing surface and the surface of each metal component, and the accumulation of the oxide skin can cause the main steam valve to have the jamming phenomenon when opening and closing, and further cause the sealing effect to be greatly discounted. Especially, when the oxide skin is tightly attached to the sealing part of the main steam valve core and the valve seat, the traditional grinding method can remove part of the oxide skin, but it is often difficult to ensure that the sealing performance of the main steam valve is not affected after the oxide skin is removed. The mutual impact grinding mode of the main steam valve core and the valve seat is the best solution to solve the above problems, and the grinding method of the sealing surface aims to obtain high dimensional accuracy, geometric shape accuracy and surface roughness through accurate processing, so as to ensure that the main steam valve can maintain its original sealing performance.

[0003] At present, in the implementation of the grinding process, since the main steam valve core and the valve rod are connected together, it is usually necessary to manually lift and drop the valve rod frequently with the help of manpower, so that the main steam valve core and the valve seat can be repeatedly ground. Since the valve rod and the main steam valve core are heavy, this operation not only has extremely high labor intensity, but also usually needs multiple people to take turns, and the grinding of the valve core and the valve seat usually takes 5 days, which accounts for more than half of the total maintenance time, and the total time reaches 7 days. This not only has low efficiency, affects the timely recovery of the steam turbine, greatly consumes human resources, and also has the safety risk of object impact in the operation process. Especially for the precision valve with extremely high precision requirement, in order to realize the original sealing performance, a device for grinding the sealing part of the main steam valve core and the valve seat of the steam turbine is urgently needed. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at providing a steam turbine main steam valve grinding device, which can solve the problems of low efficiency and difficulty in guaranteeing the original sealing performance of the manual grinding of the main steam valve core and the valve seat of the steam turbine.

[0005] In order to solve the above problems, the utility model adopts the technical scheme: this turbine main steam valve grinding device, including frame, power machine, transmission mechanism, cam, transmission shaft, driven part, guide rod, limit block and pendant, the frame sets up in the valve seat above main steam valve, the power machine passes through transmission mechanism drive setting in the cam rotation of frame, the cam's gyration axis is connected with the frame, the driven part is located in the frame, the transmission shaft is connected with the driven part rotation, the transmission shaft keeps linear contact with the cam's curve profile in the cam's gyration process to promote the driven part reciprocating motion in vertical direction, the curve profile includes rising section, first stop section, falling section and second stop section, the upper end of driven part is connected with the limit block above frame through the guide rod, and the lower end is connected with the valve rod through the pendant, the driven part and the main steam valve spool connected with the valve core sealing ring of valve seat are coaxially arranged.

[0006] In the technical scheme of the turbine main steam valve grinding device, the more specific technical scheme can be: the rising section is a slow rising section, and the falling section is a sharp falling section with large curvature.

[0007] In some possible embodiments, the pendant is a high-strength flexible connecting piece.

[0008] In some possible embodiments, the high-strength flexible connecting piece is a steel wire rope or a chain.

[0009] In some possible embodiments, the frame and the driven part are both frame structures.

[0010] In some possible embodiments, the power machine is a speed reduction motor.

[0011] In some possible embodiments, the transmission mechanism includes an input pulley, an output pulley and a transmission belt, the input pulley is connected with the output shaft of the power machine, the input pulley is connected with the output pulley through the transmission belt, and the output pulley is connected with the rotary shaft.

[0012] Compared with the prior art, the utility model has the following beneficial effects due to the adoption of the above technical scheme:

[0013] 1. By setting the movable power rotating cam and the transmission shaft which keeps linear contact with the curved profile surface of the cam, the rotating motion of the cam is converted into the up and down reciprocating motion of the driven part in the vertical direction, so that the main steam valve core hung below the driven part moves with it, thereby realizing the efficient grinding of the valve core sealing ring between the main steam valve core and the valve seat. The driven part and the valve core sealing ring of the valve seat are coaxially arranged, which ensures the stability and straight line motion trajectory of the main steam valve core during grinding, avoids the deviation or shaking of the main steam valve core during grinding, improves the grinding precision, and ensures that the sealing performance after grinding is not affected.

[0014] 2. The design of the slow rising section ensures that the main steam valve core can rise smoothly and slowly during lifting, avoiding the impact and vibration caused by sudden acceleration, which helps to protect the main steam valve core and the valve seat and prevent damage caused by collision or vibration during lifting. The design of the rapid falling section enables the main steam valve core to quickly fall and grind with the valve seat. During this process, the contact area between the grinding surfaces increases rapidly, and the grinding efficiency is significantly improved. At the same time, due to the relatively fast speed of the relative motion between the grinding surfaces, it helps to remove the uneven parts on the grinding surface and improve the grinding quality.

[0015] 3. The hanging part uses high-strength flexible connecting parts such as steel wire ropes or chains. Compared with rigid connection, flexible connecting parts can better disperse and alleviate the stress and impact force generated during movement, and can reduce the installation requirements, adapt to main steam valve cores and valve seats of different sizes and shapes, and adjust the grinding position of the main steam valve core by adjusting the length of the connecting part, thereby improving the flexibility and adaptability of the grinding system.

[0016] 4. The frame and the driven part adopt a frame structure, which is simple in structure, easy to manufacture, can effectively reduce the deformation caused by external force, and helps to maintain the stability and quality of grinding. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of the main steam valve grinding device of the steam turbine.

[0018] Figure 2 is Figure 1 the sectional view in A-A direction of

[0019] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0020] The utility model will be further described in detail below in combination with the drawings of the embodiments:

[0021] Figure 1 And Figure 2 The turbine main steam valve grinding device shown in the figure mainly includes a rack 10, a power machine, a transmission mechanism, a cam 5, a transmission shaft 6, a driven part 7, a guide rod 8, a limiting block 9, a hanger and a main steam valve core 14, wherein the rack 10 is stably installed above the valve seat of the main steam valve as the basic support of the whole device, ensuring the stability and accuracy during the grinding operation; the power machine drives the rotation of the cam 5 arranged in the rack 10 through the transmission mechanism, and the rotary shaft 11 of the cam 5 is connected with the rack 10; the driven part 7 is located in the rack 10, the transmission shaft 6 is rotationally connected with the driven part 7, and the transmission shaft 6 keeps linear contact with the curved profile of the cam 5 during the rotation of the cam 5 to push the driven part 7 to reciprocate in the vertical direction; the upper end of the driven part 7 is connected with the limiting block 9 above the rack 10 through the guide rod 8, and the lower end is connected with the valve rod through the hanger; the driven part 7 and the main steam valve core 14 connected with the valve rod are coaxially arranged with the valve core sealing ring of the valve seat.

[0022] In some possible embodiments, the rack 10 is made of an 8mm steel plate into a cuboid frame structure, which is connected with the field tool above the valve cover, ensuring that the center line of the driven part coincides with the center line of the valve rod when falling.

[0023] In some possible embodiments, the power machine is a speed reducer motor 1, which drives the rotation of the cam 5 through the transmission mechanism. The transmission mechanism includes an input pulley 2, an output pulley 4, a transmission belt 3 and shafts connecting them, wherein the input pulley 2 is connected with the output shaft of the speed reducer motor 1, the input pulley 2 is transmissionally connected with the output pulley 4 through the transmission belt 3, and the output pulley 4 is connected with the cam 5 through the rotary shaft 11.

[0024] The rotary shaft 11 of the cam 5 is connected with the rack 10, keeping the rotary center unchanged. The cam 5 of the embodiment is a disc cam, and the curved profile of the cam 5 includes an ascending section, a first stopping section, a descending section and a second stopping section. The design of the curved profile of the cam 5 is the key to realize the reciprocating motion of the driven part 7, as shown in the figure, Figure 2 In some possible embodiments, the cam 5 realizes four sections of "slow ascent-stop-quick descent-stop" on the profile, when the cam 5 rotates clockwise, the ascending section is a gentle slow ascent section from A point to B point, the slow ascent section works on the lifting of the main steam valve core 14, and the main steam valve core 14 is lifted up; stop at the maximum stroke at B point, which is the first stopping section; continue to rotate clockwise from B point to A point, which is a quick descent section with large curvature, the quick descent section is to realize the rapid descent of the main steam valve core, and the impact grinding effect is achieved; stop at A point, which is the second stopping section. The stopping section of other embodiments can be designed as a straight section or a cam base circle section.

[0025] In some possible embodiments, the follower 7 is a rectangular frame made of 6mm steel plate, which is located in the frame 10 and is in rotational connection with the transmission shaft 6 above the cam 5. During the rotation of the cam 5, the transmission shaft 6 keeps in linear contact with the curved profile of the cam 5 to push the follower 7 to make reciprocating movement in the vertical direction. The follower 7 does not interfere with the rotation axis 11 of the cam 5 to ensure that the follower 7 can make reciprocating movement up and down. In order to make the follower 7 drive the main valve spool 14 to make stable reciprocating movement, the upper end of the follower 7 is connected with the limiting block 9 above the frame 10 through the vertically arranged guide rod 8, and the lower end is connected with the valve rod through the sling. The frame 10 is provided with a guide hole in sliding cooperation with the guide rod 8 to ensure the stable movement of the guide rod 8 in the vertical direction and effectively prevent the follower 7 from shaking during rapid descent. The limiting block 9 plays a role in limiting the movement range of the follower 7 to ensure the accuracy of the grinding operation. It is worth mentioning that the sling is made of steel wire rope or chain and other high-strength flexible connecting members 13. When the follower makes reciprocating movement, the high-strength flexible connecting members 13 drive the valve rod and the main valve spool 14 connected with the valve rod to move together and grind with the valve seat. Preferably, the high-strength flexible connecting members 13 are connected with the follower 7 through the guide rod 12 which is in sliding cooperation with the frame 10. The valve rod and the main valve spool 14 can still remain stable after being connected with flexibility and will not shake, because the follower 7 is accurately centered during installation and basically remains coaxial with the valve rod. It is particularly crucial that during the grinding process, the valve rod and the valve cover are both installed on the valve seat according to the standard position, so that the track of the valve rod moving up and down during grinding coincides with the moving track of the valve rod during normal operation of the valve, ensuring that the corresponding accuracy is not a problem.

[0026] During manufacturing, the stroke of the cam 5 is made according to the height to be lifted, the reciprocating movement mechanism of the cam 5 is connected with the valve spool, the cam 5 is driven by the motor to make the valve spool move vertically up and down, and the purpose of mutual grinding of the valve spool and the valve seat is achieved. When the steam turbine main valve grinding device is used for grinding, the grinding agent is uniformly applied between the main valve spool 14 and the valve seat sealing surface of the valve spool, and then the speed reducer motor 1 is started. The speed reducer motor 1 drives the cam 5 to rotate through the belt pulley and the transmission belt 3, and the reciprocating movement of the follower 7 in the vertical direction is pushed by the transmission shaft 6. The cam 5 rotates one revolution, and the follower 7 sequentially experiences slow lifting, stopping, rapid descent and stopping. Referring to Figure 2In slow section, the main steam valve core 14 is smoothly lifted; in the rapid section, the main steam valve core 14 quickly falls and does impact action with the valve seat to grind. In the grinding process, the abrasive particles in the grinding agent slide or roll between the main steam valve core 14 and the valve seat surface, and the contact surface makes complex grinding motion, cutting off a very thin layer of metal oxide on the contact sealing surface. The convex part of the sealing ring surface is first ground off, then gradually reaches the required geometric shape, and finally obtains higher dimensional accuracy, geometric accuracy and surface roughness to meet the valve valve line requirements.

[0027] The volume of the steam turbine main steam valve grinding device is small, the weight is light, the cost is low, the installation is simple and fast, the work is stable, the transmission torque is large, it is not easy to be damaged, and the adjustment is convenient. After putting into use, it only takes 2 days to grind the main steam valve core and valve seat valve line, compared with manual grinding, about 3 days of maintenance time is saved in the main line maintenance, the maintenance efficiency is greatly improved, the main steam valve maintenance is recovered in advance, the steam turbine can strive for more power generation time, the coal gas is reduced, and the important role is highlighted in the stable power generation and power supply. More importantly, it reduces the labor intensity of workers, liberates labor, saves human resources, ensures the sealing of the main steam valve, and prolongs the service life of the equipment.

Claims

1. A turbine main valve lapping device characterized by: The main body is arranged above the valve seat of the main steam valve, the power machine drives the rotation of the cam arranged in the main body through the transmission mechanism, and the rotary shaft of the cam is connected with the main body; the driven part is located in the main body, the transmission shaft is rotationally connected with the driven part, the transmission shaft keeps linear contact with the curved profile surface of the cam in the rotation process of the cam to push the driven part to reciprocate in the vertical direction, and the curved profile surface comprises a rising section, a first stopping section, a falling section and a second stopping section; the upper end of the driven part is connected with the limiting block above the main body through the guide rod, and the lower end is connected with the valve rod through the hanging part, and the driven part and the main steam valve core connected with the valve rod are coaxially arranged with the valve core sealing ring of the valve seat.

2. The steam turbine main valve lapping device of claim 1, wherein: The rising section is a gentle slow rising section, and the falling section is a sharp falling section with large curvature.

3. A turbine valve grinder according to claim 1 or 2, characterised in that: The hanging part is a high-strength flexible connecting part.

4. The steam turbine main valve lapping device of claim 3, wherein: The high-strength flexible connecting part is a steel wire rope or a chain.

5. The steam turbine main valve lapping device of claim 1, wherein: The main body and the driven part are both frame structures.

6. The steam turbine main valve lapping device of claim 1, wherein: The power machine is a speed reduction motor.

7. The steam turbine main valve lapping device of claim 6, wherein: The transmission mechanism comprises an input pulley, an output pulley and a transmission belt, the input pulley is connected with the output shaft of the power machine, the input pulley is connected with the output pulley through the transmission belt, and the output pulley is connected with the rotary shaft.

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