Steam bypass valve

Abstract

The utility model discloses a steam bypass valve which comprises a valve body provided with a medium inlet and a medium outlet. The valve cage is arranged at the position, corresponding to the medium inlet, in the valve body in a matched mode, and the valve cage is provided with an overflowing channel for a medium to flow into the valve cage from the medium inlet; the valve element assembly is arranged in the valve cage in a matched mode, and the valve element assembly and the valve cage are matched to control the medium to flow from the medium inlet to the medium outlet. The fastening assembly comprises a valve cover, a pressing flange and a four-element ring, wherein the valve cover, the pressing flange and the four-element ring are arranged in the valve body in a matched mode. Through the design of the structure of the steam bypass valve, the steam bypass valve can reliably operate for a long time under the medium pressure of 32 MPa and the medium temperature exceeding 625 DEG C, and the use requirements under the actual working conditions that the working parameters such as the pressure, the temperature and the flow of a steam medium of a coal-fired steam turbine unit are gradually increased can be well met.

Description

Technical Field

[0001] The utility model belongs to the technical field of valves, and in particular relates to a steam bypass valve. Background Art

[0002] During the operation of the steam turbine system of coal-fired units, steam is used as the working medium of the system, and its operating parameters will be adjusted as the operating load changes. The steam bypass valve is a key auxiliary equipment for adjusting the parameters of the steam turbine, and has very high requirements for its sealing performance, operating stability, reliability of component connections, and accuracy of adjustment.

[0003] The existing bypass valve is usually installed by welding or threaded connection. The welding connection method makes maintenance extremely inconvenient; the threaded connection method is very easy to oxidize when exposed to high temperature environment, and the bolts are prone to fatigue or even failure under the long-term action of high-temperature media, which brings serious safety hazards to the use of bypass valves. At the same time, the installation and coordination between the internal components of the bypass valve will directly affect the performance of the bypass valve.

[0004] The above problems are common in the steam bypass valves commonly used at present. With the upgrading of coal-fired steam turbine unit parameters, the working parameters of the steam medium such as pressure, temperature, flow rate, etc. are gradually increasing, and the adjustment range is wider, which puts higher requirements on the stable and reliable operation of the steam bypass valve. Utility Model Content

[0005] The utility model aims to provide a steam bypass valve to meet the requirements of a coal-fired steam turbine unit for long-term working stability and reliability of the steam bypass valve.

[0006] The utility model is realized by the following technical solutions:

[0007] Steam bypass valve, including:

[0008] A valve body, wherein the valve body is provided with a medium inlet and a medium outlet;

[0009] A valve cage, wherein the valve cage is arranged in a position corresponding to the medium inlet in the valve body, and the valve cage is provided with a flow passage for the medium to flow from the medium inlet into the valve cage;

[0010] A valve core assembly, wherein the valve core assembly is arranged in the valve cage and cooperates with the valve cage to control the flow of the medium from the medium inlet to the medium outlet;

[0011] The fastening assembly includes a valve cover, a clamping flange and a four-way ring that are cooperatively arranged in the valve body. The valve cover is arranged at the upper end of the valve cage and cooperates with the upper end face of the valve cage. The clamping flange is arranged between the valve cover and the four-way ring. The four-way ring and the clamping flange cooperate to limit the movement of the clamping flange away from the valve cover. An adjusting assembly is arranged between the clamping flange and the valve cover. The adjusting assembly is used to apply a force in a relative direction between the clamping flange and the valve cover so that the valve cover can clamp and fix the valve cage in the valve body.

[0012] In some embodiments, the valve core assembly includes:

[0013] A main valve core, wherein the main valve core is a hollow structure, and a valve core channel is provided at one end of the main valve core;

[0014] A pre-start valve core, the pre-start valve core is arranged in cooperation with the main valve core and can move axially along the main valve core in the main valve core, the pre-start valve core includes a valve core body, a valve stem arranged at one end of the valve core body and a valve core plunger arranged at the other end of the valve core body, the valve core plunger cooperates with the valve core channel and can control the flow of the medium through the valve core channel, and the valve core body is provided with a balancing flow channel along its axial direction for the medium to flow from one end of the valve core body to the other end;

[0015] A secondary four-in-one ring, which is arranged in the main valve core and is used to limit the movement of the pre-start valve core in a direction away from the valve core channel;

[0016] The disc spring assembly is arranged between the main valve core and the pre-start valve core, and provides the pre-start valve core with a force to move it in a direction away from the valve core channel.

[0017] In some embodiments, a positioning gland is disposed in the valve body above the four-way ring, and the positioning gland cooperates with the inner cavity of the four-way ring and is pressed tightly on the four-way ring.

[0018] In some embodiments, the adjusting assembly includes a plurality of adjusting screws, the adjusting screws are threadedly connected to the clamping flange, and one end of the adjusting screw can be pressed against the valve cover.

[0019] In some embodiments, a valve core auxiliary sealing surface is provided on the main valve core at the valve core channel position, and a plunger sealing surface cooperating with the valve core auxiliary sealing surface is provided on the valve core plunger.

[0020] In some embodiments, the valve stem passes through the valve cover and extends out of the valve body, and an anti-leakage seal is provided between the valve stem and the valve cover.

[0021] In some embodiments, the valve cage includes a valve cage body and a valve seat for cooperating with the valve body, and the valve cage body and the valve seat are an integrally formed structure.

[0022] In some embodiments, a valve seat sealing surface is disposed on the valve seat, and a valve core main sealing surface cooperating with the valve seat sealing surface is disposed on the valve core assembly.

[0023] In some embodiments, a sound-absorbing cage is provided at the medium outlet position in the valve body. The sound-absorbing cage is provided at one end of the valve cage and is connected to the valve cage so that the medium flowing out of the valve cage flows into the sound-absorbing cage. The sound-absorbing cage is provided with a sound-absorbing channel for the medium to flow out.

[0024] In some embodiments, the valve cage and the sound-absorbing cage are configured to be spherically matched at the ends.

[0025] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0026] 1) The steam bypass valve adopts a modular stacking structure design and a four-ring snap-on connection method, which reduces the difficulty of installation and maintenance of the steam bypass valve and improves the convenience of maintenance of the steam bypass valve.

[0027] 2) The four-ring fastening connection method avoids the problem of fatigue and failure of traditional bolt connections when subjected to tensile stress under cyclic high temperature and high pressure conditions, and can ensure the stability of the structural position of the internal components of the bypass valve during long-term operation, thereby improving the reliability of the long-term operation of the steam bypass valve and its good sealing performance.

[0028] 3) The valve cage adopts an integrated structure, which solves the problem of assembly axis shape deviation caused by the conventional split structure and well ensures the coaxiality between the valve cage and the valve body.

[0029] 4) The cage and the silencer cage are spherically matched, which can automatically adapt to the vertical deviation between the valve body mounting surface and its axis during assembly, and form a good fit between the cage and the silencer cage, thereby ensuring the sealing performance of the steam bypass valve.

[0030] 5) Through the structural design of the steam bypass valve and the selection of appropriate materials, this type of steam bypass valve can achieve long-term and reliable operation at a medium pressure of 32MPa and a medium temperature exceeding 625℃, and can well meet the actual working conditions of the coal-fired steam turbine unit where the working parameters such as pressure, temperature, flow and so on of the steam medium gradually increase. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 It is a schematic diagram of the structure of the steam bypass valve in the embodiment of the utility model.

[0033] Figure 2 It is a schematic diagram of the structure of the fastening assembly in an embodiment of the utility model.

[0034] Figure 3 It is a schematic diagram of the four-ring structure in the embodiment of the utility model.

[0035] Figure 4 It is a schematic diagram of the structure of the valve core assembly in the embodiment of the utility model.

[0036] Figure 5 Schematic diagram of the valve cage structure in the embodiment of the utility model.

[0037] Figure 6 It is a schematic diagram of the matching structure between the valve cage and the silencer cage in the embodiment of the utility model.

[0038] in:

[0039] 10. valve body, 11. medium inlet, 12. medium outlet, 13. valve body mounting seat;

[0040] 20. valve cage, 21. valve cage body, 22. valve seat, 221. valve seat sealing surface, 23. flow passage;

[0041] 30. Valve core assembly, 31. Main valve core, 311. Valve core channel, 312. Valve core main sealing surface, 313. Valve core secondary sealing surface, 32. Pre-start valve core, 321. Valve core body, 322. Valve stem, 323. Valve core plunger, 3231. Plunger sealing surface, 33. Secondary four-in-one ring, 34. Disc spring assembly;

[0042] 40. Fastening assembly, 41. Valve cover, 42. Clamping flange, 43. Four-way ring, 431. Four-way ring flap, 44. Adjusting screw, 45. Positioning gland;

[0043] 50. Silence cage, 51. Silence passage. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments.

[0045] Reference Figure 1 and Figure 2In some embodiments of the present invention, the steam bypass valve includes a valve body 10 and a valve cage 20, a valve core assembly 30 and a fastening assembly 40 arranged in the valve body.

[0046] The valve body 10 serves as a carrier of the steam bypass valve. The interior of the valve body is configured as a hollow structure. A medium inlet 11 and a medium outlet 12 are provided on the valve body.

[0047] The valve cage 20 is arranged in a position corresponding to the medium inlet in the valve body, and a flow passage 23 is arranged on the valve cage 20 for the medium to flow from the medium inlet into the valve cage. Figure 1 As shown, both ends of the valve cage are matched with the inner cavity of the valve body, and are arranged between the medium inlet and the medium outlet, and cooperate with the valve core assembly to realize the switch control of the steam bypass valve.

[0048] The valve core assembly 30 is arranged in the valve cage 20 and cooperates with the valve cage to control the flow of the medium from the medium inlet to the medium outlet. Figure 1 Taking the valve core assembly structure in as an example, when the valve core assembly moves to the flow channel position, the flow channel can be blocked to prevent the medium from entering the valve cage, and the steam bypass valve is shut off through the sealing cooperation between the valve core assembly and the lower end outlet of the valve cage; when the valve core assembly moves upward to release the blockage of the flow channel, the medium can enter the valve cage and flow out from the medium outlet, thereby opening the steam bypass valve.

[0049] Reference Figure 2 The fastening assembly 40 includes a valve cover 41, a clamping flange 42 and a four-way ring 43 which are arranged in cooperation with each other in the valve body. The valve cover 41 is arranged at the upper end of the valve cage 20 and cooperates with the upper end face of the valve cage. The clamping flange 42 is arranged between the valve cover 41 and the four-way ring 43. The four-way ring 43 cooperates with the clamping flange 42 to limit the movement of the clamping flange away from the valve cover. An adjusting assembly is arranged between the clamping flange 42 and the valve cover 41. The adjusting assembly is used to apply a force in a relative direction between the clamping flange and the valve cover so that the valve cover can clamp and fix the valve cage in the valve body.

[0050] The fastening assembly adopts the combination of valve cover, clamping flange and four-way ring. By using the structural characteristics of the four-way ring, a downward force is applied to the valve cover to apply a stable clamping force to the valve cage. The overall structure of the fastening assembly is simple, which improves the stability of the bypass valve structure. Based on the characteristics of the four-way ring installation, it is convenient to maintain the bypass valve.

[0051] In some embodiments, the adjustment assembly includes a plurality of adjustment screws 44, which are threadedly connected to the clamping flange 42, and one end of the adjustment screw can be pressed against the valve cover 41. The clamping force of the valve cover on the valve cage at different positions can be adjusted by the adjustment screw, and the force is transmitted to the four-in-one ring through the clamping flange, so that the four-in-one ring can evenly bear the force of the medium on the valve cover and clamp the valve cage.

[0052] In some embodiments, a positioning gland 45 is disposed above the four-way ring in the valve body 10, and the positioning gland 45 cooperates with the inner cavity of the four-way ring 43 and is pressed against the four-way ring 43. Figure 3 The four-in-one ring 43 usually includes two sets of four-in-one ring petals 431. When installed, the two sets of four-in-one ring petals 431 are respectively embedded in the corresponding annular grooves on the valve body to form a four-in-one ring. The cooperation between the positioning gland and the inner cavity of the four-in-one ring can prevent the four-in-one ring from loosening at the installation position.

[0053] In some embodiments, reference Figure 4 , the valve core assembly includes:

[0054] The main valve core 31 is a hollow structure. A valve core channel 311 is provided at one end of the main valve core 31 , and the medium can enter the main valve core through the valve core channel.

[0055] The pre-start valve core 32 is arranged in cooperation with the main valve core and can move axially along the main valve core in the main valve core; the pre-start valve core 32 includes a valve core body 321, a valve stem 322 arranged at one end of the valve core body and a valve core plunger 323 arranged at the other end of the valve core body, the valve core plunger 323 cooperates with the valve core channel 311 to control the flow of the medium through the valve core channel, and a balancing flow channel (not shown in the figure) is arranged on the valve core body 321 along its axial direction for the medium to flow from one end of the valve core body to the other end.

[0056] Auxiliary four-way ring 33 is arranged in the main valve core 31, and is used to limit the movement of the pre-start valve core in the direction away from the valve core channel. The structure of the auxiliary four-way ring is the same as that of the four-way ring, and its installation method on the main valve core is basically the same as the installation of the four-way ring on the valve body. When the steam bypass valve is opened, the valve stem is operated to move the pre-start valve core in the direction away from the valve core channel. When the pre-start valve core moves to the position of the auxiliary four-way ring, the cooperation between the two drives the main valve core to move in the opening direction, and the steam bypass valve is opened.

[0057] The disc spring assembly 34 is arranged between the main valve core 31 and the pre-start valve core 32, and provides a force for the pre-start valve core to move away from the valve core channel. The disc spring assembly 34 includes one or more disc springs arranged in layers.

[0058] The balancing flow channel on the pre-start valve core can be a groove arranged on the circumferential surface of the valve core body along the axial direction of the valve core body or a through hole arranged on the valve core body. When the steam bypass valve is opened and closed by the valve core assembly, due to the cooperation between the pre-start valve core and the main valve core and the setting of the balancing flow channel on the pre-start valve core, the pressure on both sides of the valve core assembly during the opening and closing operations can be well balanced, which facilitates the operation of the steam bypass valve.

[0059] In some embodiments, a valve core auxiliary sealing surface 313 is provided on the main valve core 31 at the valve core channel position, and a plunger sealing surface 3231 that cooperates with the valve core auxiliary sealing surface is provided on the valve core plunger 323. The cooperation between the valve core auxiliary sealing surface and the plunger sealing surface realizes the shut-off operation of the medium through the valve core channel, and forms a good sealing effect in the valve core assembly.

[0060] In some embodiments, the valve stem 322 passes through the valve cover 41 and extends out of the valve body 10, and an anti-leakage seal is provided between the valve stem 322 and the valve cover 41 to achieve the matching setting between the valve core assembly in the valve body and the valve cover.

[0061] In existing bypass valves, the valve cage and valve seat usually adopt a split structure. Due to the influence of processing accuracy, it is often difficult to ensure their shape and position relationship during assembly. In particular, when the valve seat mounting hole on the valve body is deformed, it will cause the series of parts in the bypass valve that use this as the installation reference to be misaligned. Since the valve cage and the valve seat are rigidly connected, the assembly position between them cannot be corrected, so leakage is very likely to occur.

[0062] In view of the above problems, in some embodiments, referring to Figure 5 The valve cage 20 includes a valve cage body 21 and a valve seat 22 for cooperating with the valve body. The valve cage body 21 and the valve seat 22 are integrally formed structures, so that the valve cage has an integral structure to solve the above-mentioned problems existing in the split structure.

[0063] A valve seat sealing surface 221 is provided on the valve seat 22, and a valve core main sealing surface 312 cooperating with the valve seat sealing surface is provided on the main valve core 21 of the valve core assembly. Through the cooperation between the valve seat sealing surface and the valve core main sealing surface, good sealing performance of the steam bypass valve can be guaranteed when it is shut down.

[0064] In some embodiments, a silencer cage 50 is provided at the medium outlet position in the valve body. The silencer cage 50 is provided at one end of the valve cage and communicated with the valve cage, so that the medium flowing out of the valve cage flows into the silencer cage. A silencer channel 51 for the medium to flow out is provided on the silencer cage, and the medium flows out from the medium outlet through the silencer channel. The setting of the silencer channel on the silencer cage can eliminate the noise generated by the flow of the medium during the operation of the steam bypass valve.

[0065] In some embodiments, the valve cage 20 and the sound-absorbing cage 50 are configured to be spherically matched at the ends. Figure 6 As shown, the mating end surface of the end of the cage 20 is set as a concave spherical surface, and the mating end surface of the end of the silencer cage 50 is set as a convex spherical surface. In the assembly structure of the steam bypass valve, the silencer cage is arranged in the valve body and is installed by forming a limited fit between the protrusion arranged at its end and the valve body mounting seat 13 on the valve body. Since the cage and the silencer cage are arranged to be spherical, they can automatically adapt to the deviation of the verticality between the valve body mounting surface and the valve body axis during assembly, and can well ensure the coaxiality of the cage installed in the valve body, thereby ensuring the performance of the steam bypass valve.

[0066] In the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the utility model product is usually placed when used. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model.

[0067] In addition, if the terms "horizontal" or "vertical" appear in the description of the present invention, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0068] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. Steam bypass valve, characterized in that: include: A valve body, wherein the valve body is provided with a medium inlet and a medium outlet; A valve cage, wherein the valve cage is arranged in a position corresponding to the medium inlet in the valve body, and the valve cage is provided with a flow passage for the medium to flow from the medium inlet into the valve cage; A valve core assembly, wherein the valve core assembly is arranged in the valve cage and cooperates with the valve cage to control the flow of the medium from the medium inlet to the medium outlet; The fastening assembly includes a valve cover, a clamping flange and a four-way ring that are cooperatively arranged in the valve body. The valve cover is arranged at the upper end of the valve cage and cooperates with the upper end face of the valve cage. The clamping flange is arranged between the valve cover and the four-way ring. The four-way ring and the clamping flange cooperate to limit the movement of the clamping flange away from the valve cover. An adjusting assembly is arranged between the clamping flange and the valve cover. The adjusting assembly is used to apply a force in a relative direction between the clamping flange and the valve cover so that the valve cover can clamp and fix the valve cage in the valve body.

2. The steam bypass valve according to claim 1, characterized in that: The valve core assembly comprises: A main valve core, wherein the main valve core is a hollow structure, and a valve core channel is provided at one end of the main valve core; A pre-start valve core, the pre-start valve core is arranged in cooperation with the main valve core and can move axially along the main valve core in the main valve core, the pre-start valve core includes a valve core body, a valve stem arranged at one end of the valve core body and a valve core plunger arranged at the other end of the valve core body, the valve core plunger cooperates with the valve core channel and can control the flow of the medium through the valve core channel, and the valve core body is provided with a balancing flow channel along its axial direction for the medium to flow from one end of the valve core body to the other end; A secondary four-in-one ring, which is arranged in the main valve core and is used to limit the movement of the pre-start valve core in a direction away from the valve core channel; The disc spring assembly is arranged between the main valve core and the pre-start valve core, and provides the pre-start valve core with a force to move it in a direction away from the valve core channel.

3. The steam bypass valve according to claim 1, characterized in that: A positioning gland is arranged above the four-way ring in the valve body, and the positioning gland cooperates with the inner cavity of the four-way ring and is pressed tightly on the four-way ring.

4. The steam bypass valve according to claim 1, characterized in that: The adjusting assembly comprises a plurality of adjusting screws, which are threadedly connected to the clamping flange, and one end of the adjusting screw can be pressed against the valve cover.

5. The steam bypass valve according to claim 2, characterized in that: The main valve core is provided with a valve core auxiliary sealing surface at the valve core passage position, and the valve core plunger is provided with a plunger sealing surface that matches the valve core auxiliary sealing surface.

6. The steam bypass valve according to claim 2, characterized in that: The valve stem passes through the valve cover and extends out of the valve body, and an anti-leakage sealing member is arranged between the valve stem and the valve cover.

7. The steam bypass valve according to claim 1, characterized in that: The valve cage comprises a valve cage body and a valve seat for cooperating with the valve body, and the valve cage body and the valve seat are an integrally formed structure.

8. The steam bypass valve according to claim 7, characterized in that: The valve seat is provided with a valve seat sealing surface, and the valve core assembly is provided with a valve core main sealing surface that matches the valve seat sealing surface.

9. The steam bypass valve according to claim 1 or 7, characterized in that: A silencer cage is provided at the medium outlet position in the valve body. The silencer cage is provided at one end of the valve cage and is connected to the valve cage so that the medium flowing out of the valve cage flows into the silencer cage. The silencer cage is provided with a silencer channel for the medium to flow out.

10. The steam bypass valve according to claim 9, characterized in that: The valve cage and the silencer cage are configured to be spherically matched at the ends.

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