Stop valve for conveying high-pressure steam

Abstract

The utility model relates to a stop valve for conveying high-pressure steam, which comprises a valve body, a main valve seat is arranged in the valve body, a main valve clack is arranged on the main valve seat, a fixing sleeve is arranged on the outer side of the main valve clack, the fixing sleeve is connected with the main valve seat, an auxiliary valve seat is arranged in the main valve clack, an auxiliary valve clack is arranged above the auxiliary valve seat, and the auxiliary valve seat is attached to the auxiliary valve clack. First springs are arranged on the auxiliary valve seat and the auxiliary valve clack, a first through hole is formed in the fixing sleeve, a second through hole is formed in the portion, on the inner side of the first through hole, of the main valve clack, the first through hole is communicated with the inlet end of the valve body, an inner cavity of the auxiliary valve seat is communicated with the outlet end of the valve body, and the first through hole is communicated with an inner cavity of the auxiliary valve seat through the second through hole. A valve cover is arranged on the valve body and the fixing sleeve, a valve rod is arranged on the valve cover and the auxiliary valve clack, and a valve clack gland is arranged on the main valve clack. And the valve clack is difficult to separate from the valve seat to achieve a valve opening state. The utility model has the advantages of convenient use and wide market prospect.

Description

Technical Field

[0001] The utility model relates to the field of stop valves, in particular to a stop valve for conveying high-pressure steam. Background Art

[0002] The inner edge of the steam seal body is embedded with a steam seal sheet, which forms a steam seal with the steam seal sheet or wall teeth installed on the rotor. The commonly used steam turbine steam seal is a non-contact flow resistance labyrinth steam seal, which is composed of a number of annular gaps and chambers arranged in sequence. Under the action of pressure difference, the steam flows through the gap at high speed into a relatively large chamber. The steam flow suddenly expands and produces a violent vortex. Most of the kinetic energy is converted into heat energy. Only a small part of the kinetic energy passes through the next gap at the residual speed. The above process is repeated step by step, and the throttling effect on the steam flow is used to seal. Steam seals are configured at the part where the turbine rotor passes through the cylinder. The steam seal is also called a shaft seal. The steam seal of the steam turbine generally includes two parts: the front and rear steam seals. The function of the front steam seal is to prevent and reduce the leakage of steam in the cylinder to the outside, to prevent high-temperature steam from leaking into the bearing seat, causing the bearing temperature to rise and the lubricating oil to contain water; the function of the rear steam seal is to prevent air from leaking into the exhaust cylinder to prevent the vacuum of the unit from deteriorating. The effect of steam turbine steam seal affects the efficiency of steam turbine, and even affects the safe operation of steam turbine in serious cases; reliable steam turbine steam seal is a necessary guarantee for the safe operation of steam turbine, and the stability of steam turbine seal steam pressure is a necessary condition to ensure the effect of steam turbine steam seal, so steam turbine seal steam pressure regulation is a very important part of steam turbine control.

[0003] The shut-off valve is installed in the sealing steam pressure regulating system. The function of the shut-off valve is to quickly phase the sealing steam supply when the steam turbine needs to be shut down in an emergency, thereby stopping the supply of sealing steam to the steam seal of the steam turbine. After eliminating the hidden dangers, the shutdown state can be converted to the start-up state again. The first thing to do during the conversion process is to open the shut-off valve. Since the shut-off valve acts on the high-pressure steam transmission pipeline, the high-pressure steam has a higher pressure, and the corresponding high-pressure steam itself has a higher temperature. In the process of reopening the shut-off valve, since the pressure upstream of the shut-off valve is brought by high-pressure steam and the downstream of the shut-off valve is directly connected to the turbine steam seal, this causes the back pressure of the shut-off valve to be much lower than the positive pressure of the shut-off valve. That is, the shut-off valve needs to overcome the additional resistance caused by the difference between the positive pressure of the shut-off valve and the back pressure of the shut-off valve during the opening process to open the shut-off valve. Under the influence of the additional resistance, it is easy for the valve disc and the valve seat of the shut-off valve to require more driving force to overcome the additional resistance so that the valve disc and the valve seat of the shut-off valve can reach the open state. Therefore, there is room for improvement in the shut-off valve, so that the action of the valve disc and the valve seat of the shut-off valve reaching the open state can be easier to achieve, thereby meeting market demand. Summary of the invention

[0004] In view of the deficiencies in the prior art, the utility model provides a stop valve for conveying high-pressure steam that can reduce the difficulty of the valve disc to separate from the valve seat and reach the valve open state due to the excessively high difference between the valve disc back pressure and the positive pressure in the closed state under the action of high-pressure steam, so as to overcome the defects in the prior art.

[0005] The technical scheme adopted by the utility model is: a stop valve for conveying high-pressure steam, comprising a valve body, a main valve seat is arranged in the valve body, a main valve disc is arranged on the main valve seat, the main valve disc and the main valve seat are fitted together, a fixing sleeve is arranged on the outer side of the main valve disc, the bottom end of the fixing sleeve is connected to the top of the main valve seat, an auxiliary valve seat is arranged on the inner side of the main valve disc, an auxiliary valve disc is arranged in the main valve disc above the auxiliary valve seat, the auxiliary valve seat and the auxiliary valve disc are fitted together, a first spring is arranged on the auxiliary valve seat and the auxiliary valve disc, a first through hole is arranged on the fixing sleeve, a second through hole is arranged on the main valve disc inside the first through hole, the first through hole is connected to the inlet end of the valve body, the inner cavity of the auxiliary valve seat is connected to the outlet end of the valve body, the first through hole and the inner cavity of the auxiliary valve seat are connected through the second through hole, a valve cover is arranged on the top of the valve body and the top of the fixing sleeve, a valve stem is arranged on the valve cover and the auxiliary valve disc, and a valve disc pressure cover is arranged on the main valve disc above the valve stem.

[0006] Preferably, a piston ring is provided on the main valve disc, and a side of the piston ring away from the main valve disc is movably connected to an inner side of the fixed sleeve. The number of piston rings is several, and the several piston rings are evenly distributed on the main valve disc along the direction from close to the valve disc gland to away from the valve disc gland.

[0007] Preferably, a packing sealing groove is provided on the top of the valve cover, and a packing seat ring, a sealing packing and a packing sleeve are provided in sequence in the packing sealing groove from bottom to top. The packing seat ring, the sealing packing and the packing sleeve are all mounted on the valve stem, and a packing pressure plate is provided on the valve stem above the packing pressure sleeve, and adjusting bolts are provided on the packing pressure plate and the valve cover.

[0008] Preferably, a pressure regulating sleeve is provided on the bottom of the main valve seat, and the pressure regulating sleeve adopts a cylindrical structure with an opening at the top, a pressure regulating tube is provided on the inner side of the pressure regulating sleeve, the top of the pressure regulating tube is connected to the bottom of the auxiliary valve flap, the inner cavity of the pressure regulating tube is connected to the inner cavity of the auxiliary valve flap, the pressure regulating tube adopts a circular tubular structure, a first pressure regulating hole is provided on the top of the pressure regulating tube, a second pressure regulating hole is provided on the pressure regulating sleeve, and the first pressure regulating hole and the outlet end of the valve body are connected through the second pressure regulating hole.

[0009] Preferably, the number of the second pressure regulating holes and the number of the first pressure regulating holes are both multiple, and the multiple first pressure regulating holes and the multiple second pressure regulating holes are distributed in a spirally ascending manner outside the central axis of the pressure regulating tube.

[0010] Preferably, a mounting frame is provided on the valve cover, a hydraulic cylinder is provided on the mounting frame, the hydraulic cylinder includes a cylinder body and a driving rod, a coupling is provided on the driving rod and the valve stem, a support ring is provided on the driving rod, a second spring is provided on the driving rod, the second spring is located above the coupling and between the support ring and the mounting frame.

[0011] Preferably, a mounting plate is provided on one side of the mounting frame, a fourth through hole is provided on the mounting plate, a first pressure sensor is provided on the mounting plate above the fourth through hole, a second pressure sensor is provided on the mounting plate below the fourth through hole, and an indicator plate is provided on the fourth through hole and the coupling.

[0012] The beneficial effects of the utility model are as follows: firstly, the utility model reduces the driving force required to be applied to the main valve seat and the main valve disc during the opening and closing process of the high-pressure steam valve due to the excessive resistance caused by the difference between the back pressure and the positive pressure, and arranges the auxiliary valve seat and the auxiliary valve disc on the inner side of the main valve disc, and utilizes the auxiliary valve disc to open from the auxiliary valve seat first, thereby reducing the pressure difference on both sides of the main valve disc, reducing the additional resistance encountered by the main valve disc and the main valve seat when opening, thereby prompting the main valve disc and the main valve seat to reach an open state.

[0013] Secondly, a mounting plate is provided on one side of the mounting frame described in the utility model, a fourth through hole is provided on the mounting plate, a first pressure sensor is provided on the mounting plate above the fourth through hole, a second pressure sensor is provided on the mounting plate below the fourth through hole, and an indicator plate is provided on the fourth through hole and the coupling; installing the second pressure sensor and the first pressure sensor facilitates feedback of the position reached by the indicator plate.

[0014] The utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improved work efficiency, good social and economic benefits, and is a product that is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model.

[0016] Figure 2 for Figure 1 A partial enlarged schematic diagram of detail A.

[0017] Figure 3 It is a structural schematic diagram of the components of the utility model. DETAILED DESCRIPTION

[0018] like Figures 1 to 3As shown, a stop valve for conveying high-pressure steam includes a valve body 1, a main valve seat 2 is arranged in the valve body 1, a main valve flap 3 is arranged on the main valve seat 2, the main valve flap 3 and the main valve seat 2 are fitted, a fixing sleeve 4 is arranged on the outside of the main valve flap 3, the bottom end of the fixing sleeve 4 is connected to the top of the main valve seat 2, an auxiliary valve seat 5 is arranged on the inside of the main valve flap 3, an auxiliary valve flap 6 is arranged in the main valve flap 3 above the auxiliary valve seat 5, the auxiliary valve seat 5 and the auxiliary valve flap 6 are fitted, and a first spring is arranged on the auxiliary valve seat 5 and the auxiliary valve flap 6. 7. A first through hole 8 is provided on the fixed sleeve 4, a second through hole 9 is provided on the main valve disc 3 inside the first through hole 8, the first through hole 8 is connected with the inlet end of the valve body 1, the inner cavity of the auxiliary valve seat 5 is connected with the outlet end of the valve body 1, the first through hole 8 and the inner cavity of the auxiliary valve seat 5 are connected through the second through hole 9, a valve cover 10 is provided on the top of the valve body 1 and the top of the fixed sleeve 4, a valve stem 11 is provided on the valve cover 10 and the auxiliary valve disc 6, and a valve disc gland 12 is provided on the main valve disc 3 above the valve stem 11.

[0019] The main valve disc 3 is provided with a piston ring 13, and the side of the piston ring 13 away from the main valve disc 3 is movably connected to the inner side of the fixed sleeve 4. The number of piston rings 13 is several, and the several piston rings 13 are evenly distributed on the main valve disc 3 along the direction from close to the valve disc gland 12 to away from the valve disc gland 12. The number of the first through holes 8 is several, and the several first through holes 8 are evenly distributed in a star shape outside the central axis of the inner cavity of the auxiliary valve seat 5, and a second through hole 9 is correspondingly distributed inside each first through hole 8. The auxiliary valve disc 6 is provided with a fifth through hole 41, and the inner cavity of the valve body 1 above the auxiliary valve disc 6 and the inner cavity of the valve body 1 below the auxiliary valve disc 6 are connected through the fifth through hole 41. The number of the fifth through holes 41 is several, and the several fifth through holes 41 are evenly distributed in a star shape outside the central axis of the valve stem 11, and the central axis of the valve stem 11, the central axis of the auxiliary valve seat 5 and the central axis of the auxiliary valve disc 6 are located on the same axis. Thus, the pressure balance between the upper and lower sides of the auxiliary valve flap 6 is achieved during the opening process of the auxiliary valve flap 6 and the auxiliary valve seat 5 or the closing process of the auxiliary valve flap 6 and the auxiliary valve seat 5, making it easier to open or close the auxiliary valve flap 6 and the auxiliary valve seat 5. Furthermore, a limiting mechanism is provided on the auxiliary valve flap 6 and the main valve flap 3, and the limiting mechanism includes a limiting slider 42 provided on the outer side of the auxiliary valve flap 6 and a limiting slide groove 43 provided on the inner side of the main valve flap 3. The limiting slide groove 43 and the limiting slider 42 are movably connected. The limiting slider 42 adopts a block structure that can slide along the extension direction of the limiting slide groove 43. The limiting slide groove 43 extends from the direction close to the auxiliary valve seat 5 to the direction away from the auxiliary valve seat 5. The number of the limiting mechanisms is at least two, and several of the limiting mechanisms are evenly distributed in a star shape on the outer side of the central axis of the valve stem 11. Installing several of the limiting mechanisms distributed in a star shape facilitates the position limitation of the auxiliary valve flap 6 in the movement direction of the main valve flap 3.

[0020] The shape of the top of the main valve seat 2 matches the shape of the bottom of the fixing sleeve 4, the bottom of the fixing sleeve 4 is sleeved on the top of the main valve seat 2, the shape of the top of the fixing sleeve 4 matches the shape of part of the valve cover 10, the top of the fixing sleeve 4 is sleeved on the valve cover 10, a first sealing ring 14 is arranged between the valve body 1 and the valve cover 10 and between the valve cover 10 and the fixing sleeve 4, a first fixing bolt 15 is arranged on the valve body 1 and the valve cover 10, and a second sealing ring 16 is arranged between the valve body 1 and the main valve seat 2. A first flange 17 is arranged on the inlet end of the valve body 1, a second flange 18 is arranged on the outlet end of the valve body 1, second fixing bolts 19 are respectively arranged on the first flange 17 and the valve body 1, and on the valve body 1 and the second flange 18, and a third sealing ring 20 is respectively arranged between the first flange 17 and the valve body 1, and between the valve body 1 and the second flange 18. The first sealing ring 14, the second sealing ring 16 and the third sealing ring 20 are all metal spiral wound gaskets with graphite as filler.

[0021] A packing sealing groove 21 is provided at the top of the valve cover 10, and a packing seat ring 22, a sealing packing 23 and a packing pressing sleeve 24 are provided in sequence from bottom to top in the packing sealing groove 21. The packing seat ring 22, the sealing packing 23 and the packing pressing sleeve 24 are all mounted on the valve stem 11, and a packing pressing plate 25 is provided on the valve stem 11 above the packing pressing sleeve 24. The packing pressing sleeve 24 adopts a tubular structure, and the top of the packing pressing sleeve 24 adopts a truncated cone-shaped tubular structure. Part of the shape of the packing pressing plate 25 matches the top of the packing pressing sleeve 24, the packing pressing plate 25 and the packing pressing sleeve 24 are movably connected, and adjusting bolts 26 are provided on the packing pressing plate 25 and the valve cover 10. Installing the sealing packing 23 facilitates the gap between the sealing valve cover 10 and the valve stem 11. Installing the packing seat ring 22, the packing gland 24, the packing pressure plate 25 and the adjusting bolt 26 facilitates tightening the adjusting bolt 26 to drive the packing pressure plate 25 to move downward, thereby driving the packing gland 24 to move downward, and then realizing that the sealing packing 23 is deformed again under the extrusion of the packing gland 24 and the packing seat ring 22, thereby reducing the gap between the sealing valve cover 10 and the valve stem 11 to achieve the technical purpose of re-sealing.

[0022] A pressure regulating sleeve 27 is arranged at the bottom of the main valve seat 2. The pressure regulating sleeve 27 adopts a cylindrical structure with an opening at the top. A pressure regulating tube 28 is arranged inside the pressure regulating sleeve 27. The pressure regulating tube 28 adopts a tubular structure. The top of the pressure regulating tube 28 is connected to the bottom of the auxiliary valve flap 6. The inner cavity of the pressure regulating tube 28 is connected to the inner cavity of the auxiliary valve flap 6. The pressure regulating tube 28 adopts a circular tubular structure. A first pressure regulating hole 29 is arranged at the top of the pressure regulating tube 28. A second pressure regulating hole 30 is arranged on the pressure regulating sleeve 27. The first pressure regulating hole 29 is connected to the outlet end of the valve body 1 through the second pressure regulating hole 30. The number of the second pressure regulating holes 30 and the number of the first pressure regulating holes 29 are both multiple. The multiple first pressure regulating holes 29 and the multiple second pressure regulating holes 30 are all spirally ascending and distributed outside the central axis of the pressure regulating tube 28. The apertures of the plurality of first pressure regulating holes 29 gradually increase along the direction from close to the main valve seat 2 to far away from the main valve seat 2 , and the apertures of the plurality of second pressure regulating holes 30 gradually decrease along the direction from close to the main valve seat 2 to far away from the main valve seat 2 .

[0023] The valve cover 10 is provided with a mounting frame 31, and a hydraulic cylinder 32 is provided on the mounting frame 31. The hydraulic cylinder 32 includes a cylinder body and a driving rod. A coupling 33 is provided on the driving rod and the valve stem 11. A support ring 34 is provided on the driving rod. A second spring 35 is provided on the driving rod. The second spring 35 is located above the coupling 33 and between the support ring 34 and the mounting frame 31. When the main valve seat 2 and the main valve flap 3 are in an open state, the second spring 35 is in a compressed state. When the hydraulic cylinder 32 drives the valve stem 11 to perform a closing action, the second spring 35 is gradually reset. Compared with simply using hydraulic oil to drive the hydraulic cylinder 32 to perform a closing action, the elastic force released by the reset of the second spring 35 prompts the driving rod of the hydraulic cylinder 32 to drive the valve stem 11 and thus drive the main valve flap 3 to overcome the resistance brought by high-pressure steam to perform a closing action, so that the main valve seat 2 and the main valve flap 3 are more likely to reach a closed state. Furthermore, a mounting plate 36 is provided on one side of the mounting frame 31, a fourth through hole 37 is provided on the mounting plate 36, a first pressure sensor 38 is provided on the mounting plate 36 above the fourth through hole 37, a second pressure sensor 39 is provided on the mounting plate 36 below the fourth through hole 37, and an indicator plate 40 is provided on the fourth through hole 37 and the coupling 33. When the main valve seat 2 and the main valve disc 3 are in a fully closed state, the indicator plate 40 and the second pressure sensor 39 are in contact with each other, and when the main valve seat 2 and the main valve disc 3 are in a fully open state, the indicator plate 40 and the first pressure sensor 38 are in contact with each other.

[0024] like Figures 1 to 3As shown, in the closed state, the main valve flap 3 and the main valve seat 2 are in contact with each other, and the auxiliary valve seat 5 and the auxiliary valve flap 6 are also in contact with each other. The opening action of the product includes the following steps:

[0025] First, the hydraulic cylinder 32 receives hydraulic oil to drive the driving rod of the hydraulic cylinder 32 to move toward the cylinder body of the hydraulic cylinder 32, thereby driving the valve stem 11, the coupling 33 and the support ring 34 to make corresponding movements. During this process, the second spring 35 is gradually compressed, the position of the indicator plate 40 gradually rises, and the auxiliary valve flap 6 moves with the valve stem 11, thereby driving the auxiliary valve flap 6 and the auxiliary valve seat 5 to separate from each other, the first spring 7 gradually resets, and the auxiliary valve flap 6 drives the position of the pressure regulating tube 28 to rise. During this process, the high-pressure steam entering the inner cavity of the valve body 1 from the direction of the first flange 17 enters the inner cavity of the pressure regulating tube 28 through the first through hole 8, the second through hole 9 and the inner cavity of the auxiliary valve seat 5 in turn. At this time, the second pressure regulating hole 30 on the pressure regulating sleeve 27 is blocked by the pressure regulating tube 28.

[0026] Then, as the position of the auxiliary valve flap 6 continues to rise, the second through hole 9 gradually moves to above the first through hole 8, and the second through hole 9 is gradually blocked by the fixing sleeve 4, and the plurality of first pressure regulating holes 29 are gradually all located on the inner side of the second through hole 9. In this process, the plurality of second pressure regulating holes 30 shielded by the pressure regulating tube 28 are also gradually located below the bottom end of the pressure regulating tube 28.

[0027] Finally, when the plurality of second pressure regulating holes 30 are all located below the bottom end of the pressure regulating tube 28, the plurality of first pressure regulating holes 29 are all connected with the second through hole 9, and the second through hole 9 is located on the inner side of the fixed sleeve 4 above the first through hole 8, the product reaches the open state. When the product reaches the open state, the high-pressure steam entering the inner cavity of the valve body 1 from the direction of the first flange 17 passes through the first through hole 8 in turn, undergoes the first throttling through the plurality of first pressure regulating holes 29, and then enters the inner cavity between the pressure regulating tube 28 and the pressure regulating sleeve 27. Then, the high-pressure steam in the inner cavity between the pressure regulating tube 28 and the pressure regulating sleeve 27 undergoes the second throttling through the plurality of second pressure regulating holes 30, and then is discharged to the downstream pipeline through the second flange 18. At this time, the indicator plate 40 and the sensing end of the first pressure sensor 38 are in contact with each other.

[0028] When the product is in the open state and needs to be closed, the following actions are included:

[0029] First, the hydraulic cylinder 32 receives hydraulic oil to drive the driving rod of the hydraulic cylinder 32 to move toward the direction away from the cylinder body of the hydraulic cylinder 32. During this process, the elastic force generated by the compression of the second spring 35 is released, thereby prompting the driving rod of the hydraulic cylinder 32 to accelerate the movement and thereby reduce the resistance encountered when the hydraulic oil enters the cylinder body of the hydraulic cylinder 32. Under the action of the valve stem 11 driven by the driving rod of the hydraulic cylinder 32, the auxiliary valve flap 6 moves toward the auxiliary valve seat 5. During the movement of the auxiliary valve flap 6, the gas below the auxiliary valve flap 6 is transported to the top of the auxiliary valve flap 6 through the fifth through hole 41. During this process, the first spring 7 is gradually compressed until the auxiliary valve flap 6 and the auxiliary valve seat 5 are in a fit state.

[0030] Then, the hydraulic cylinder 32 continues to receive the hydraulic oil to drive the driving rod of the hydraulic cylinder 32 to move in the direction away from the cylinder body of the hydraulic cylinder 32, and the driving rod of the hydraulic cylinder 32 drives the valve stem 11 to move, thereby driving the auxiliary valve flap 6 and the auxiliary valve seat 5 in the fitted state to move, thereby driving the main valve flap 3 to move in the direction of the main valve seat 2. In this process, a number of second pressure regulating holes 30 are gradually blocked by the pressure regulating tube 28, and a number of first pressure regulating holes 29 are gradually blocked by the pressure regulating sleeve 27, so that the number of first pressure regulating holes 29 connected to the first through hole 8 is getting smaller and smaller, and the pressure regulating holes 29 are connected to the first through hole 8. The number of second pressure regulating holes 30 connected to the inner cavity between the tube 28 and the pressure regulating sleeve 27 is also decreasing; thereby, the pressure of the high-pressure steam after the first throttling through the first pressure regulating hole 29 connected to the first through hole 8 is getting lower and lower, and the pressure of the high-pressure steam after the second throttling through the second pressure regulating hole 30 connected to the inner cavity between the pressure regulating tube 28 and the pressure regulating sleeve 27 is also getting lower and lower, thereby gradually increasing the difference in pressure between the inner cavity of the valve body 1 on the side of the main valve disc 3 facing the first flange 17 and the inner cavity of the valve body 1 on the side of the main valve disc 3 facing the second flange 18.

[0031] Finally, when the main valve flap 3 and the main valve seat 2 are in contact with each other, and the auxiliary valve seat 5 and the auxiliary valve flap 6 are also in contact with each other, the product reaches a closed state. At this time, the high-pressure steam transported from the upstream enters the inner cavity of the valve body 1 from the first flange 17 and then enters the cavity between the main valve flap 3 and the auxiliary valve flap 6 through the first through hole 8 and the second through hole 9 in sequence. Finally, the high-pressure steam in the cavity between the main valve flap 3 and the auxiliary valve flap 6 passes through the fifth through hole 41 and the gap between the valve stem 11 and the valve flap gland 12 and enters the inner cavity of the fixed sleeve 4 above the main valve flap 3. At this time, the pressure of the high-pressure steam above the auxiliary valve flap 6 reaches the maximum value, and the indicator plate 40 and the sensing end of the second pressure sensor 39 are in contact with each other.

[0032] Through this embodiment, the resistance caused by the difference between the back pressure and the positive pressure during the opening and closing process of the high-pressure steam valve is too large, so the driving force required to be applied to the main valve seat 2 and the main valve flap 3 during the closing process is reduced, and the auxiliary valve seat 5 and the auxiliary valve flap 6 are arranged on the inner side of the main valve flap 3. The auxiliary valve flap 6 is first opened from the auxiliary valve seat 5, thereby reducing the pressure difference on both sides of the main valve flap 3, reducing the additional resistance encountered by the main valve flap 3 and the main valve seat 2 when opening, thereby prompting the main valve flap 3 and the main valve seat 2 to reach a closed state.

[0033] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made based on the structures, features and principles described in the patent scope of the present invention should be included in the patent application scope of the present invention.

Claims

1. A stop valve for conveying high-pressure steam, comprising a valve body (1), a main valve seat (2) being arranged in the valve body (1), a main valve flap (3) being arranged on the main valve seat (2), the main valve flap (3) and the main valve seat (2) being in close contact with each other, characterized in that: A fixing sleeve (4) is arranged on the outside of the main valve disc (3), the bottom end of the fixing sleeve (4) is connected to the top of the main valve seat (2), an auxiliary valve seat (5) is arranged on the inside of the main valve disc (3), an auxiliary valve disc (6) is arranged in the main valve disc (3) above the auxiliary valve seat (5), the auxiliary valve seat (5) and the auxiliary valve disc (6) are fitted together, a first spring (7) is arranged on the auxiliary valve seat (5) and the auxiliary valve disc (6), a first through hole (8) is arranged on the fixing sleeve (4), and a spring (7) is arranged on the main valve disc (3) inside the first through hole (8) A second through hole (9) is provided, the first through hole (8) is connected to the inlet end of the valve body (1), the inner cavity of the auxiliary valve seat (5) is connected to the outlet end of the valve body (1), the first through hole (8) and the inner cavity of the auxiliary valve seat (5) are connected via the second through hole (9), a valve cover (10) is provided on the top of the valve body (1) and the top of the fixed sleeve (4), a valve stem (11) is provided on the valve cover (10) and the auxiliary valve disc (6), and a valve disc gland (12) is provided on the main valve disc (3) above the auxiliary valve disc (6).

2. The stop valve for conveying high-pressure steam according to claim 1, characterized in that: The main valve disc (3) is provided with a piston ring (13), and a side of the piston ring (13) away from the main valve disc (3) is movably connected to an inner side of the fixed sleeve (4). The number of piston rings (13) is a plurality, and the plurality of piston rings (13) are evenly distributed on the main valve disc (3) along a direction from close to the valve disc gland (12) to away from the valve disc gland (12).

3. The stop valve for conveying high-pressure steam according to claim 1, characterized in that: The top of the valve cover (10) is provided with a packing sealing groove (21), and the packing sealing groove (21) is provided with a packing seat ring (22), a sealing packing (23) and a packing pressing sleeve (24) in sequence from bottom to top. The packing seat ring (22), the sealing packing (23) and the packing pressing sleeve (24) are all mounted on the valve stem (11), and a packing pressing plate (25) is provided on the valve stem (11) above the packing pressing sleeve (24), and an adjusting bolt (26) is provided on the packing pressing plate (25) and the valve cover (10).

4. The stop valve for conveying high-pressure steam according to claim 1, characterized in that: A pressure regulating sleeve (27) is arranged on the bottom of the main valve seat (2). The pressure regulating sleeve (27) adopts a cylindrical structure with an opening at the top. A pressure regulating tube (28) is arranged on the inner side of the pressure regulating sleeve (27). The top of the pressure regulating tube (28) is connected to the bottom of the auxiliary valve flap (6). The inner cavity of the pressure regulating tube (28) is connected to the inner cavity of the auxiliary valve flap (6). The pressure regulating tube (28) adopts a cylindrical structure. A first pressure regulating hole (29) is arranged on the top of the pressure regulating tube (28). A second pressure regulating hole (30) is arranged on the pressure regulating sleeve (27). The first pressure regulating hole (29) and the outlet end of the valve body (1) are connected via the second pressure regulating hole (30).

5. The stop valve for conveying high-pressure steam according to claim 4, characterized in that: The number of the second pressure regulating holes (30) and the number of the first pressure regulating holes (29) are both multiple, and the multiple first pressure regulating holes (29) and the multiple second pressure regulating holes (30) are distributed in a spirally ascending manner outside the central axis of the pressure regulating tube (28).

6. The stop valve for conveying high-pressure steam according to claim 1, characterized in that: The valve cover (10) is provided with a mounting frame (31), the mounting frame (31) is provided with a hydraulic cylinder (32), the hydraulic cylinder (32) comprises a cylinder body and a driving rod, a coupling (33) is provided on the driving rod and the valve stem (11), a supporting ring (34) is provided on the driving rod, a second spring (35) is provided on the driving rod, the second spring (35) is located above the coupling (33) and between the supporting ring (34) and the mounting frame (31).

7. The stop valve for conveying high-pressure steam according to claim 6, characterized in that: A mounting plate (36) is provided on one side of the mounting frame (31), a fourth through hole (37) is provided on the mounting plate (36), a first pressure sensor (38) is provided on the mounting plate (36) above the fourth through hole (37), a second pressure sensor (39) is provided on the mounting plate (36) below the fourth through hole (37), and an indicator plate (40) is provided on the fourth through hole (37) and the coupling (33).

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