Cage-type dual wedge throttle valve

Abstract

A cage-type dual wedge throttle valve, comprising: a housing having an inner cavity; a valve cover arranged at the top of the housing; a valve seat arranged in the inner cavity, wherein the valve seat comprises an outer valve seat and an inner valve seat, and a plurality of flow holes are distributed on the peripheral wall of the outer valve seat; a valve core, which comprises two wedge-shaped surfaces and two cylindrical surfaces which are axially symmetrically arranged about the central axis, wherein the cylindrical surfaces face the direction in which a fluid flows into the inner cavity, and the cylindrical surfaces can fit the inner wall of the inner valve seat; and a valve stem having the two ends respectively connected to a driving device and the valve core, wherein under the driving of the driving device, the valve stem can drive the valve core to reciprocate in the valve seat in the axial extension direction of the valve stem. By means of the above solution, primary throttling is achieved when a fluid passes through the outer valve seat, and secondary throttling is achieved as the valve core gradually extends into the inner valve seat; moreover, the valve core comprises wedge-shaped surfaces, and a long throttling stroke is formed, thereby improving the throttling switching performance of the throttle valve; the symmetrical arrangement of the two wedge-shaped surfaces can balance the pressure on the two sides, thereby improving the stability of the valve core under force.

Description

Cage type double wedge throttle valve

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application 202311865814.7 filed on December 29, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The invention relates to the technical field of oil and gas exploitation, and in particular to a cage-type double-wedge throttle valve. Background Art

[0004] During oil and gas production, well control throttle valves are typically used on choke and kill manifolds to regulate fluid flow, maintaining an ideal balance between wellhead back pressure and formation pressure, discharging overflow and maintaining wellbore pressure balance. The primary factors influencing throttle valve performance are the structure of the valve core and seat. Good linearity and erosion resistance are key performance indicators for throttle valves.

[0005] At present, throttle valves are mainly classified according to the structure of the valve core and valve seat, including: cylindrical throttle valves, needle throttle valves, cage throttle valves, orifice throttle valves and wedge throttle valves. Among them, when the cylindrical throttle valve is closed, there is a normally open gap channel, that is, it will not be completely closed, and the linearity is poor, and the flow adjustment range is small. At the same time, when the cylindrical throttle valve core is in the extended state and the throttle valve tends to close, the suspended part of the valve core is lengthened without support. Under the erosion of the high-pressure fluid on the inlet side, resonance is easily formed downstream, resulting in cantilever beam problems, which manifests as valve core breakage. The needle throttle valve mainly has poor linearity and cantilever beam problems, and the actual throttling effect is poor. The cage throttle valve has poor erosion resistance, and the throttle hole and valve body are severely eroded by the high-pressure fluid. The orifice throttle valve also has poor erosion resistance due to the fluid being close to the pipe wall. The existing wedge throttle valve is usually a single wedge throttle valve, which has cantilever problems and unstable flow control problems.

[0006] Therefore, providing a throttle valve with good throttling characteristics and erosion resistance has become a technical problem that needs to be solved urgently. Summary of the Invention

[0007] The purpose of the present invention is to overcome the problems of poor throttling linearity and short service life of the throttle valve in the prior art.

[0008] In order to achieve the above-mentioned object, the present invention provides a cage-type double wedge throttle valve, comprising a housing, the housing comprising an inner cavity for fluid flow; a valve cover arranged on the top of the housing, the valve cover having a mounting channel; a valve seat arranged in the inner cavity, the valve seat comprising an outer valve seat and an inner valve seat, a plurality of flow holes distributed on the peripheral wall of the outer valve seat, the outer valve seat being arranged in the inner cavity, the inner valve seat being arranged in the outer valve seat, and being located at the bottom of the outer valve seat and axially staggered with the flow holes, so that the fluid in the inner cavity The valve core comprises two wedge-shaped surfaces and two cylindrical surfaces axially symmetrically arranged about the central axis, the cylindrical surfaces facing the direction in which the fluid flows into the inner cavity, and the cylindrical surfaces can fit with the inner wall of the inner valve seat; and a valve stem, one end of the valve stem is connected to the driving device, and the other end is connected to the valve core through the mounting channel, and the valve stem can drive the valve core to reciprocate in the valve seat along the axial extension direction of the valve stem under the drive of the driving device.

[0009] Optionally, an angle formed by a center line of the wedge surface and the central axis is a wedge angle, and the range of the wedge angle is 5°-30°.

[0010] Optionally, the wedge angle ranges from 10° to 20°.

[0011] Optionally, the wedge-shaped surface is a convex surface.

[0012] Optionally, the valve core further includes two guide surfaces axially symmetrically arranged about the central axis, and the guide surfaces are arranged at an end of the wedge surface away from the valve stem.

[0013] Optionally, there is a gap between the valve stem and the mounting channel for the fluid in the inner cavity to flow in.

[0014] Optionally, the cage-type double-wedge throttle valve provided by the present invention further includes a guide belt arranged in the installation channel and surrounding the valve stem, wherein the guide belt can protect and straighten the valve stem, and a first annular gap is formed between the guide belt and the valve stem.

[0015] Optionally, a countersunk hole is formed at one end of the installation passage close to the outer valve seat, and the top end of the outer valve seat can extend into the countersunk hole.

[0016] Optionally, a sealing assembly is provided at one end of the installation channel away from the outer valve seat to prevent the fluid from flowing out through the gap between the valve stem and the installation channel.

[0017] Optionally, the sealing assembly includes a packing seal ring provided in a gap between the valve stem and the mounting channel and a packing pressure cap for pressing the packing seal ring.

[0018] Optionally, a second sealing ring is installed between the packing sealing ring and the packing pressure cap.

[0019] Optionally, the driving device includes an electric actuator, a rotating sleeve rotatably connected to the electric actuator, a bearing seat sleeved outside the rotating sleeve and threadedly connected to the valve cover, a bearing arranged between the rotating sleeve and the bearing seat, and a screw assembly arranged in the rotating sleeve, the screw assembly includes a screw and a nut threadedly connected to the screw, and one end of the screw away from the nut is connected to the valve stem, wherein the electric actuator is configured to drive the rotating sleeve to rotate, thereby driving the nut to rotate, so that the screw reciprocates along its axial extension direction.

[0020] Optionally, the cage-type double-wedge throttle valve provided by the present invention further includes an anti-rotation pin, which passes through the bearing seat and abuts against the valve cover.

[0021] Optionally, the cage-type double-wedge throttle valve provided by the present invention also includes a limit pin, one end of which abuts against the keyway on the valve stem, and the other end is fixedly connected to the mounting channel, so that the fluid in the inner cavity can flow into the gap between the valve stem and the mounting channel through the keyway.

[0022] Optionally, the inner cavity includes a fluid cavity extending axially and connected to the bottom of the mounting channel, a fluid inlet channel extending radially and connected to one side of the fluid cavity, and a fluid outflow channel extending axially and connected to the bottom of the fluid cavity, wherein the diameter of the fluid cavity is larger than the diameters of the mounting channel, the fluid inlet channel and the fluid outflow channel, and the lower end of the valve seat is partially inserted into the fluid outflow channel.

[0023] Optionally, the cage-type double-wedge throttle valve provided by the present invention further includes a protective sleeve arranged in the fluid outflow channel, and the upper end of the protective sleeve is engaged with the lower end of the valve seat.

[0024] Optionally, a first sealing ring is provided between the upper end of the protective sleeve and the lower end of the valve seat.

[0025] Optionally, a seating step is formed in the fluid outflow channel, and the protective cover is stopped on the seating step.

[0026] Optionally, the inner cavity further includes a pressure relief outlet channel extending radially and connected to the other side of the fluid cavity, and a pressure relief valve is provided on the side of the pressure relief outlet channel away from the fluid cavity to discharge the pressure of the inner cavity.

[0027] The cage-type double-wedge throttle valve provided by the present invention can achieve at least the following beneficial effects:

[0028] (1) The valve seat includes an outer valve seat and an inner valve seat. A plurality of flow holes are provided on the peripheral wall of the outer valve seat. When the high-pressure incoming flow passes through the flow holes of the outer valve seat from the shell flow channel, the flow area changes, thereby realizing the primary throttling, improving the flow field distribution of the high-pressure and high-speed fluid passing through, and thus reducing vibration and noise. As the valve stem moves, the valve core continuously extends into the outer valve seat and the inner valve seat, and a flow channel is formed between the wedge surface and the inner valve seat. As the valve core extends downward into the inner valve seat, the flow area of ​​the flow channel between the wedge surface and the inner valve seat gradually decreases, thereby realizing the secondary throttling. Compared with the cylindrical structure of the conventional cylindrical throttle valve and the needle structure of the needle throttle valve, the valve core of the present invention has a wedge surface. The wedge surface forms a longer throttling surface, thereby forming a longer throttling stroke, which is more conducive to the fine control of the throttle valve by the driving device, thereby improving the linearity and controllability of the throttle valve.

[0029] (2) The valve core in the present invention has two wedge-shaped surfaces and two cylindrical surfaces axially symmetrically arranged about the central axis. Compared with the conventional single wedge structure, the two symmetrically arranged wedge-shaped surfaces can balance the fluid pressure on both sides, improve the force stability of the valve stem and valve core, and extend the service life of the valve core.

[0030] (3) The guide belt is arranged in the installation channel and surrounds the valve stem. The guide belt has a certain elasticity and can guide and straighten the reciprocating motion of the valve stem. The guide belt can also protect the valve stem and prevent the valve stem from being worn by the installation channel.

[0031] (4) In the present invention, the cylindrical surface of the valve core faces the direction of fluid flow into the inner cavity, while the wedge surface is parallel to the direction of fluid flow into the inner cavity, further reducing the scouring of the wedge surface by the high-pressure fluid, thereby extending the service life of the valve core. In addition, the cylindrical surface can fit with the inner wall of the inner valve seat in the inner valve seat, so that the inner valve seat can provide stable support for the valve core and valve stem, further enhancing the anti-scouring ability of the valve core and ensuring the stability of the reciprocating motion of the valve core. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic structural diagram of a cage-type double-wedge throttle valve provided by the present invention;

[0033] FIG2 is a schematic structural diagram of a screw rod assembly of a cage-type double-wedge throttle valve provided by the present invention;

[0034] 3 is a schematic diagram of the valve core installation of the cage-type double-wedge throttle valve provided by the present invention;

[0035] FIG4 is a schematic diagram of the countersunk hole at the lower end of the valve cover of the cage-type double-wedge throttle valve provided by the present invention;

[0036] FIG5 is a schematic diagram of the flow direction of high-pressure fluid in a cage-type double-wedge throttle valve provided by the present invention;

[0037] FIG6 is a schematic structural diagram of the outer valve seat of the cage-type double-wedge throttle valve provided by the present invention;

[0038] 7 is a schematic diagram of the channel of the housing of the cage-type double-wedge throttle valve provided by the present invention;

[0039] FIG8 is a schematic diagram of a valve core of a cage-type double-wedge throttle valve provided by the present invention;

[0040] 9 is a schematic diagram of a valve stem of a cage-type double-wedge throttle valve provided by the present invention;

[0041] 10 is a schematic diagram of the inner valve seat of the cage-type double wedge throttle valve provided by the present invention;

[0042] FIG11 is a cross-sectional view of the valve core of the cage-type double-wedge throttle valve provided by the present invention. DETAILED DESCRIPTION

[0043] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are intended to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0044] In the present invention, unless otherwise specified, "plurality" means greater than or equal to two. Terms such as "upper," "lower," "left," "right," "inner," "outer," "top," and "bottom" are intended to indicate positions or relationships for the sole purpose of simplifying and facilitating the description of the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limitations on the present invention. When the absolute position of the objects being described changes, the relative positional relationships may also change accordingly.

[0045] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are simply used to distinguish different parts. The terms "include," "comprise," and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of other elements also being included.

[0046] It should also be noted that, in the description of this invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, removable connections, or integral connections; they can be directly connected or indirectly connected through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0047] All terms used herein have the same meanings as understood by one of ordinary skill in the art to which the present invention belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined herein.

[0048] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0049] The present invention aims to solve the problems of poor throttling linearity and weak erosion resistance of throttle valves in the prior art and provides a cage-type double-wedge throttle valve.

[0050] 1, 6 and 8, the cage-type double wedge throttle valve provided by the present invention includes: a housing 11, which includes an inner cavity for fluid flow; a valve cover 7, which is arranged on the top of the housing 11 and has a mounting channel; a valve seat, which is arranged in the inner cavity, and the valve seat includes an outer valve seat 16 and an inner valve seat 13, and a plurality of flow holes 16b are distributed on the peripheral wall of the outer valve seat 16, the outer valve seat 16 is arranged in the inner cavity, and the inner valve seat 13 is arranged in the outer valve seat 16, and is located at the bottom of the outer valve seat 16 and axially staggered with the flow hole 16b, so that the fluid in the inner cavity flows through the outer valve seat 16 in sequence. and an inner valve seat 13; a valve core 12, the valve core 12 includes two wedge surfaces 12b and two cylindrical surfaces 12a axially symmetrically arranged about the central axis, the cylindrical surfaces 12a face the direction in which the fluid flows into the inner cavity, and the cylindrical surfaces 12a can fit with the inner wall of the inner valve seat 13; and a valve stem 21, one end of the valve stem 21 is connected to the driving device, and the other end is connected to the valve core 12 through the mounting channel, and there is a gap between the valve stem 21 and the mounting channel for the inner cavity fluid to flow in. The valve stem 21 can drive the valve core 12 to reciprocate in the valve seat along the axial extension direction of the valve stem 21 under the drive of the driving device.

[0051] The cage-type double wedge throttle valve provided by the present invention, first, the valve seat includes an outer valve seat 16 and an inner valve seat 13. On the one hand, a plurality of flow holes 16b are provided on the peripheral wall of the outer valve seat 16. During the axial reciprocating motion of the valve core 12, the area of ​​the flow holes 16b through which the fluid passes is changed, thereby achieving initial throttling, improving the flow field distribution of the high-pressure and high-speed fluid passing through, and thus reducing vibration and noise; on the other hand, the valve core 12 continuously extends into the outer valve seat 16 and the inner valve seat 13 as the valve stem 21 moves, and the wedge surface 12b and the inner valve seat 1 3, as the valve core 12 extends downward into the inner valve seat 13, the flow area of ​​the flow channel between the wedge surface 12b and the inner valve seat 13 gradually decreases, thereby realizing secondary throttling. Compared with the cylindrical structure of the conventional cylindrical throttle valve and the needle structure of the needle throttle valve, the valve core 12 of the present invention has a wedge surface 12b, and the wedge surface 12b forms a longer throttling surface, thereby forming a longer throttling stroke, which is more conducive to the fine control of the throttle valve by the driving device, thereby improving the linearity and controllability of the throttle valve.

[0052] Secondly, the valve core 12 in the present invention has two wedge surfaces 12b and two cylindrical surfaces 12a that are axially symmetrically arranged about the central axis. Compared with the conventional single wedge structure, the double wedge symmetrical arrangement can balance the impact force of the high-pressure fluid on both sides of the wedge surface 12b, improve the force stability of the valve stem 21 and the valve core 12, and extend the service life of the valve core.

[0053] In addition, in conventional wedge-shaped throttle valves, the wedge surface of the valve core is usually oriented toward the direction of fluid inflow to achieve a throttling effect. However, in the present invention, the cylindrical surface 12a of the valve core 12 is oriented toward the direction of fluid inflow into the inner cavity, and the wedge surface 12b is parallel to the direction of fluid inflow into the inner cavity, thereby further reducing the erosion of the wedge surface 12b by the high-pressure fluid, thereby extending the service life of the valve core 12. In addition, the outer diameter of the cylindrical surface 12a in the inner valve seat 13 is the same as the inner diameter of the inner valve seat 13, so that the cylindrical surface 12a and the inner wall of the inner valve seat 13 are in contact, allowing the inner valve seat 13 to provide stable support for the valve core 12 and the valve stem 21, further enhancing the erosion resistance of the valve core 12 and ensuring the stability of the reciprocating motion of the valve core 12 and the valve stem 21.

[0054] Optionally, as shown in Figure 8 , the angle formed between the central axis of valve core 12 and the centerline of wedge surface 12b is wedge angle α. According to one embodiment of the caged double-wedge throttle valve of the present invention, the inlet pressure of the throttle valve was set to 175 MPa, and the inlet flow rate was set to 15 m / s. The throttling characteristics and erosion resistance of the throttle valve with different wedge angles α were tested. The flow rate of the fluid at the end of valve core 12 away from valve stem 21 was calculated for wedge angles α of 50°, 30°, 20°, 15°, 10°, and 5°, respectively. The calculation results are shown in the following table.

[0055] Table 1

[0056] Therefore, as shown in Table 1, when the wedge angle α of the valve core 12 is 50°, the flow rate of the fluid at the end of the valve core 12 exceeds 150 m / s, causing significant erosion of the valve core 12 by the fluid. However, when the wedge angle α is between 5° and 30°, the flow rate of the fluid at the end of the valve core 12 can be reduced, thereby reducing the erosion caused by the fluid on the valve core 12. Furthermore, when the wedge angle α is between 10° and 20°, the erosion caused by the fluid on the valve core 12 is further reduced.

[0057] Optionally, as shown in FIG8 , the valve core 12 further includes two guide surfaces 12c axially symmetrically arranged about the central axis. The guide surfaces 12c are provided at the end of the wedge-shaped surface 12b away from the valve stem 21. The guide surfaces 12c can reduce vortices formed by the fluid at the end of the valve core 12 away from the valve stem 21, thereby reducing erosion of the valve core 12, the inner valve seat 13, and the protective sleeve 14 described below by the high-pressure fluid, thereby extending the service life of the valve core 12, the inner valve seat 13, and the protective sleeve 14.

[0058] Optionally, referring to FIG. 1 , the valve cover 7 is connected to the threaded hole on the top of the housing 11 via a second bolt 19 .

[0059] Furthermore, a metal gasket 8 is provided at the connection between the lower end surface of the valve cover 7 and the upper end surface of the top of the shell 11. The metal gasket 8 can be used to seal the valve cover 7 and the shell 11 to prevent the fluid in the inner cavity of the shell 11 from flowing out of the shell 11.

[0060] Optionally, a gap is defined between the valve stem 21 and the mounting passage for the fluid in the inner cavity to flow in. The fluid flowing into the inner cavity further flows into the gap, thereby connecting the gap with the inner cavity and eliminating the pressure differential between the gap and the inner cavity. This, in turn, eliminates the pressure differential during the reciprocating motion of the valve stem 21 between the gap and the inner cavity. This reduces the resistance experienced by the valve stem 21 during its reciprocating motion between the gap and the inner cavity, preventing significant vibration of the valve stem 21 during its reciprocating motion and facilitating the stability of the reciprocating motion of the valve stem 21.

[0061] Optionally, referring to Figure 1, the cage-type double wedge throttle valve provided by the present invention also includes a guide belt 10 arranged in the installation channel and surrounding the valve stem 21. The guide belt 10 has a certain elasticity and can guide and straighten the reciprocating motion of the valve stem 21. In addition, the guide belt 10 can also protect the valve stem 21 and prevent the valve stem 21 from being worn by the installation channel.

[0062] Furthermore, a first annular gap is formed between the guide strip 10 and the valve stem 21, thereby allowing the fluid in the inner cavity to flow into the gap between the mounting channel and the valve stem 21, thereby eliminating the stroke pressure difference of the valve stem 21 reciprocating between the gap and the inner cavity.

[0063] Optionally, referring to Figures 1 and 4, a countersunk hole 7a is formed at one end of the mounting passage near the outer valve seat 16, and the top end of the outer valve seat 16 can extend into the countersunk hole 7a. Specifically, the inner diameter of the countersunk hole 7a is equal to the outer diameter of the outer valve seat 16, and the depth of the countersunk hole 7a can be set according to actual production conditions to ensure that the valve cover 7 can provide sufficient support for the outer valve seat 16. When high-pressure fluid flows into the inner cavity, the outer valve seat 16 is equivalent to a cantilever beam, and its upper portion is prone to large displacement and vibration. By providing the countersunk hole 7a, the upper end of the outer valve seat 16 is sunk into the valve cover 7, so that the valve cover 7 can provide effective support for the upper end of the outer valve seat 16, reducing the displacement and vibration of the upper end of the outer valve seat 16, and thereby extending the service life of the outer valve seat 16.

[0064] Optionally, a sealing assembly is provided at one end of the installation channel away from the outer valve seat 16, which can seal the gap between the valve stem 21 and the installation channel to prevent the fluid in the inner cavity from flowing out of the valve cover 7 through the gap between the valve stem 21 and the installation channel.

[0065] In some embodiments of the present invention, the sealing component may be a sealing ring that seals the gap between the valve stem 21 and the installation channel.

[0066] Alternatively, optionally, referring to Figure 1, the sealing assembly includes a packing seal 18 provided in the gap between the valve stem 21 and the mounting channel and a packing pressure cap 5 for compressing the packing seal 18, wherein the packing seal 18 is provided at one end of the mounting channel away from the outer valve seat 16, the packing pressure cap 5 is provided on the side of the packing seal 18 away from the outer valve seat 16, and the packing pressure cap 5 is connected to the thread of the valve cover 7 provided above the mounting channel. By tightening the packing pressure cap 5, the packing seal 18 is compressed to achieve the gap between the valve stem 21 and the mounting channel, so as to prevent the fluid in the inner cavity from flowing out of the valve cover 7 through the gap between the valve stem 21 and the mounting channel.

[0067] Optionally, a second sealing ring 20 is provided between the packing sealing ring 18 and the packing pressure cap 5 , thereby further improving the sealing performance of the gap between the valve stem 21 and the mounting channel at the end of the valve cover 7 away from the outer valve seat 16 .

[0068] In some embodiments of the present invention, there are multiple options for the driving device. For example, the driving device can be a linear motor, which drives the valve stem 21 to reciprocate along its axial extension direction, thereby driving the valve core 12 to reciprocate along the axial extension direction of the valve stem 21, changing the fluid flow area of ​​the flow channel between the valve core 12 and the inner valve seat 13, and achieving the purpose of throttling.

[0069] Alternatively, optionally, referring to Figures 1 and 2, the driving device includes an electric actuator 1, a rotating sleeve 4 rotatably connected to the electric actuator 1, a bearing seat 22 sleeved outside the rotating sleeve and threadedly connected to the valve cover 7, a bearing 3 arranged between the rotating sleeve 4 and the bearing seat 22, and a screw assembly 23 arranged in the rotating sleeve 4, the screw assembly 23 includes a screw 23b and a nut 23a threadedly connected to the screw 23b, and the end of the screw 23b away from the nut 23a is connected to the valve stem 21.

[0070] Among them, the electric actuator 1 is configured to drive the rotating sleeve 4 to rotate. The electric actuator 1 can be an electric motor or a motor, as long as it can drive the rotating sleeve 4 to rotate. The rotation of the rotating sleeve 4 drives the nut 23a to rotate. Since the nut 23a is threadedly connected to the screw 23b, when the rotating sleeve 4 drives the nut 23a to rotate, the screw 23b reciprocates along its axial extension direction. The end of the screw 23b away from the nut 23a is connected to the valve stem 21. Referring to Figure 1, the bottom end of the screw 23b is threadedly connected to the top end of the valve stem 21. The bottom end of the valve stem 21 and the top end of the valve core 12 can be welded. The screw 23b, the valve stem 21 and the valve core 12 are coaxially arranged. Therefore, the electric actuator 1 drives the rotating sleeve 4 to rotate, and the rotating sleeve 4 drives the nut 23a to rotate together, so that the screw 23b threadedly connected to the nut 23a moves linearly along the axial extension direction of the screw 23b. Changing the rotation direction of the electric actuator can change the rotation direction of the rotating sleeve 4 and the nut 23a, thereby changing the movement direction of the screw 23b, so that the screw 23b can reciprocate along its axial extension direction, and then the screw 23b drives the valve stem 21 and the valve core 12 to reciprocate along the axial extension direction of the screw 23b, and finally changes the flow area of ​​the flow channel between the valve core 12 and the inner valve seat 13, thereby achieving a throttling effect.

[0071] In addition, the top of the bearing seat 22 is threadedly connected to the threaded hole at the bottom of the electric actuator 1 through the first bolt 2, thereby connecting the top of the bearing seat 22 to the lower end of the electric actuator 1, and the bottom of the bearing seat 22 is threadedly connected to the top of the valve cover 7.

[0072] Optionally, grease may be applied between the rotating sleeve 4 and the bearing seat 22 to reduce the rotational resistance of the rotating sleeve 4 and lower the power consumption of the electric actuator 1 .

[0073] Furthermore, referring to Figure 1 , a third sealing ring 24 is provided between the rotating sleeve 4 and the bearing seat 22. This third sealing ring 24 is located above the rotating sleeve 4 and the bearing seat 22, thereby sealing the grease between the rotating sleeve 4 and the bearing seat 22 and preventing grease from overflowing. Furthermore, a bearing 3 is provided below the rotating sleeve 4. To improve the rotational stability of the rotating sleeve 4, multiple bearings 3 may be provided. For example, two bearings 3 may be provided below the rotating sleeve 4, with the two bearings 3 arranged sequentially from top to bottom.

[0074] In addition, the lower end surface of the rotating sleeve 4 is in contact with the packing pressure cap 5, so that the entire throttle valve has a compact structure and occupies a small space.

[0075] Optionally, referring to Figure 1, the cage-type double wedge throttle valve provided by the present invention also includes an anti-rotation pin 6. Specifically, an anti-rotation pin mounting hole is provided at the bottom of the bearing seat 22. The anti-rotation pin 6 passes through the anti-rotation pin mounting hole on the bearing seat 22 and abuts against the valve cover 7, thereby preventing the bearing seat 22 from rotating during the rotation of the rotating sleeve 4.

[0076] Optionally, referring to Figures 1 and 9, a key groove 21a is provided on the valve stem 21, and the cage-type double-wedge throttle valve provided by the present invention also includes a limit pin 9, one end of the limit pin 9 abuts against the key groove 21a on the valve stem 21, and the other end can be fixedly connected to the installation channel; or, the other end of the limit pin 9 can pass through the side wall of the installation channel and abut against the shell 11. The limit pin 9 can prevent the valve stem 21 from rotating during the reciprocating motion, thereby preventing the valve core 12 from rotating during the reciprocating motion.

[0077] In addition, by adjusting the extension length of the keyway 21a toward the valve core 12, it is ensured that the fluid in the inner cavity can flow into the keyway 21a, and further flow into the gap between the valve stem 21 and the installation channel, so that the gap is connected to the inner cavity, eliminating the pressure difference between the gap and the inner cavity, and then eliminating the stroke pressure difference of the reciprocating motion of the valve stem 21 between the gap and the inner cavity, thereby reducing the resistance encountered by the valve stem 21 during the reciprocating motion between the gap and the inner cavity, preventing the valve stem 21 from vibrating greatly during the reciprocating motion, and helping to ensure the stability of the reciprocating motion of the valve stem 21.

[0078] Alternatively, in some embodiments of the present invention, a fluid channel may be provided within the valve stem 21, allowing fluid in the inner cavity to flow into the gap between the valve stem 21 and the mounting channel. For example, the inlet of the fluid channel may be provided at the end of the valve stem 21 proximal to the valve core 12, that is, the inlet of the fluid channel may be provided on the valve stem lower surface 21b (described below), and the outlet may be provided on the sidewall of the portion of the valve stem 21 located within the mounting channel, thereby allowing fluid in the inner cavity to flow through the fluid channel into the gap between the valve stem 21 and the mounting channel.

[0079] Optionally, referring to Figures 1, 3, 5 and 7, the inner cavity includes a fluid cavity 11a extending axially and connected to the bottom of the mounting channel, a fluid inlet channel 11b extending radially and connected to one side of the fluid cavity 11a, and a fluid outflow channel 11d extending axially and connected to the bottom of the fluid cavity 11a, and the lower end of the valve seat is partially inserted into the fluid outflow channel 11d, wherein the diameter of the fluid cavity 11a is larger than the diameters of the mounting channel, the fluid inlet channel 11b and the fluid outflow channel 11d. The fluid cavity 11a has a larger diameter, which can increase the accommodation volume of the fluid cavity 11a, so that when the valve core 12 is fully open, that is, when the valve core 12 is at the highest point, the flow capacity of the fluid in the fluid cavity 11a is improved, the back pressure of the throttle valve at a large displacement is reduced, and the application range of the throttle valve is expanded.

[0080] Optionally, referring to Figure 1 , the caged double-wedge throttle valve provided by the present invention further includes a protective sleeve 14 disposed within the fluid outflow passage 11d. The upper end of the protective sleeve 14 engages the lower end of the valve seat, allowing the protective sleeve 14 to cover the inner wall of the housing 11 downstream of the valve seat. This protects the inner wall of the housing 11 from long-term fluid erosion, effectively protecting the inner wall of the housing 11 and extending the service life of the housing 11. Furthermore, the protective sleeve 14 is detachable, facilitating subsequent replacement.

[0081] Optionally, the protective cover 14 may be made of tungsten carbide material, so that the protective cover 14 has high wear resistance and erosion resistance, thereby improving the protection performance of the protective cover 14 on the inner wall of the shell 11 and extending the service life of the shell 11.

[0082] Referring to Figures 1, 5, and 6, fluid flows into fluid chamber 11a through fluid inlet channel 11b. The fluid in fluid chamber 11a passes through flow holes 16b on outer valve seat 16, changing the flow area and achieving primary throttling. This improves the flow distribution of the high-pressure, high-speed fluid passing through, thereby reducing vibration and noise. The reciprocating motion of valve core 12 along its axial direction changes the flow area of ​​the flow passage between valve core 12 and inner valve seat 13, thereby achieving secondary throttling. Finally, the fluid exits the throttle valve through fluid outlet channel 11d.

[0083] 6 , multiple rows of flow holes 16 b are distributed on the outer peripheral wall of the outer valve seat 16 , and the centers of any two adjacent rows of flow holes 16 b are staggered, which is conducive to a more uniform distribution of the flow field.

[0084] In addition, referring to Figure 1 and Figure 6, the valve seat includes an outer valve seat 16 and an inner valve seat 13. The outer valve seat 16 is formed in a tubular shape. The main part of the outer valve seat 16 is arranged in the fluid cavity 11a, and a third annular gap is formed with the fluid cavity 11a. The fluid first flows into the third annular gap from the fluid inlet channel 11b, and then flows into the outer valve seat 16 through the flow hole 16b. The lower end portion of the outer valve seat 16 extends into the fluid outflow channel 11d, and the outer diameter of the outer valve seat 16 is the same as the inner diameter of the fluid outflow channel 11d, so that the outer peripheral surface of the lower end portion of the outer valve seat 16 can be engaged with the inner peripheral surface of the fluid outflow channel 11d, thereby improving the sealing performance of the outer valve seat 16 and the fluid outflow channel 11d.

[0085] 1 , 5 , and 10 , the inner valve seat 13 is formed in a tubular shape and is disposed within the outer valve seat 16 . The inner valve seat 13 is located at the bottom of the outer valve seat 16 and is axially offset from the flow hole 16 b on the outer valve seat 16 . This prevents the inner valve seat 13 from blocking the flow hole 16 b, preventing the fluid in the fluid cavity 11 a from flowing through the flow hole 16 b into the outer valve seat 16 . The inner diameter of the inner valve seat 13 is the same as the outer diameter of the cylindrical surface 12 a of the valve core 12 , allowing the inner circumference of the inner valve seat 13 to engage with the outer circumference of the cylindrical surface 12 a , thereby providing effective support for the valve core 12 . The outer diameter of the inner valve seat 13 is the same as the inner diameter of the bottom of the outer valve seat 16 , allowing the outer circumference of the inner valve seat 13 to fit closely with the inner circumference of the bottom of the outer valve seat 16 , ensuring a tight connection between the inner valve seat 13 and the outer valve seat 16 .

[0086] Optionally, referring to Figure 6, the outer valve seat 16 includes an outer valve seat thread 16a provided at the bottom of the outer valve seat 16, a flow hole 16b provided in the middle of the outer valve seat 16, and a mounting hole 16c provided on the upper end surface of the outer valve seat 16. The outer valve seat 16 extends into the fluid outflow channel 11d and is connected to the threads in the fluid outflow channel 11d via the outer valve seat thread 16a. A plurality of mounting holes 16c are arranged on the upper end surface of the outer valve seat 16, preferably four in number, evenly distributed on the upper end surface of the outer valve seat 16. When threading the outer valve seat 16 to the housing 11, a mounting rod can be inserted into the mounting hole 16c, and the mounting rod can be rotated to provide rotational torque to the outer valve seat 16, thereby driving the outer valve seat 16 to rotate and threading the outer valve seat 16 into the housing 11. In addition, there are multiple flow holes 16b distributed on the wall surface of the middle part of the outer valve seat 16. There are various distribution forms of the flow holes 16b on the wall surface of the outer valve seat 16. They can be unevenly distributed on the wall surface of the outer valve seat 16. For example, the distribution density of the flow holes 16b gradually decreases along the extension direction of the wall surface of the outer valve seat 16 from top to bottom; or, preferably, the flow holes 16b are uniformly distributed on the wall surface of the outer valve seat 16. The size of the flow holes 16b can gradually decrease along the extension direction of the wall surface of the outer valve seat 16 from top to bottom; or, multiple flow holes 16b have the same size, and the size of the flow holes 16b can be adjusted according to the size of the solid particles carried in the fluid. The shape of the flow holes 16b can be circular, elliptical or square, and can be adjusted according to actual production needs.

[0087] Optionally, referring to Figures 1, 8, 9, and 10, the valve core 12 includes two wedge surfaces 12b and two cylindrical surfaces 12a. The two wedge surfaces 12b are axisymmetric about the central axis of the valve core 12, and the two cylindrical surfaces 12a are axisymmetric about the central axis of the valve core 12. The wedge surfaces 12b can be flat, concave, or convex. According to one embodiment of the cage-type double-wedge throttle valve of the present invention, the pressure difference between the inlet and outlet pressures of the throttle valve is calculated when the wedge surfaces 12b are flat, concave, or convex, respectively. The calculation results are shown in Table 2 below.

[0088] Table 2

[0089] Therefore, as shown in Table 2, when the wedge surface 12b is convex, the pressure differential between the inlet and outlet pressures can be significantly reduced, thereby reducing the impact force exerted on the valve core 12 by the fluid passing through the throttle valve. Optionally, the convex surface comprises a flat surface, i.e., the convex surface has a diamond-shaped cross-section along the radial direction of the cylindrical surface 12a. Alternatively, the convex surface comprises a curved surface. As shown in Figure 11, the wedge surface 12b has an arc-shaped cross-section along the radial direction of the cylindrical surface 12a. Compared to a flat convex surface, a curved convex surface has the advantage of lower flow resistance.

[0090] Of course, the guide surface 12c can be a plane, a concave surface or a convex surface. According to one embodiment of the cage-type double-wedge throttle valve of the present invention, the guide surface 12c is a convex surface, which is beneficial to reduce the vortex generated by the fluid at the end of the valve core 12 away from the valve stem 21, thereby reducing the erosion of the valve core 12, the inner valve seat 13 and the protective cover 14 by the high-pressure fluid, thereby extending the service life of the valve core 12, the inner valve seat 13 and the protective cover 14.

[0091] Optionally, during the downward movement of the valve core 12, a flow channel is formed between the wedge surface 12b and the inner valve seat 13, and the flow area of ​​the flow channel between the wedge surface 12b and the inner valve seat 13 gradually decreases. When the end of the valve stem 21 close to the valve core 12 contacts the inner valve seat 13, specifically, when the valve stem lower surface 21b of the valve stem 21 contacts the inner valve seat upper surface 13a of the inner valve seat 13, the flow area of ​​the flow channel is zero, that is, the fluid cannot flow from the outer valve seat 16 to the inner valve seat 13, and the throttle valve is in a closed state.

[0092] Of course, there are many other ways to close the throttle valve. For example, the outer diameter of the valve stem 21 is set to be the same as the inner diameter of the inner valve seat 13. When the valve stem 21 extends downward into the inner valve seat 13, the fluid cannot flow from the outer valve seat 16 to the inner valve seat 13, and the throttle valve is closed.

[0093] Optionally, referring to Figure 1, the lower portion of the inner valve seat 13 extends out of the bottom of the outer valve seat 16 and is engaged with the upper end of the protective sleeve 14. A first sealing ring 15 is provided between the upper end of the protective sleeve 14 and the lower end of the valve seat. Specifically, a second annular gap is formed between the lower end surface of the outer valve seat 16, the portion of the inner valve seat 13 extending out of the outer valve seat 16, the upper end surface of the protective sleeve 14 and the side wall of the fluid outflow channel 11d. By providing the first sealing ring 15 in the second annular gap, the valve seat and the protective sleeve 14 can be more effectively sealed to prevent the fluid from flowing into the second annular gap and eroding the inner wall of the shell 11.

[0094] Optionally, referring to Figures 1, 5, and 7, a seating step 11c is formed within the fluid outflow passage 11d, and the protective sleeve 14 is stopped on the seating step 11c. The outer wall of the protective sleeve 14 is formed with a shape that matches the seating step, so that the seating step 11c can provide upward support for the protective sleeve 14, and the inner valve seat 13 can press the protective sleeve 14 downward, thereby allowing the protective sleeve 14 to be well fixed within the fluid outflow passage 11d, providing effective protection for the inner wall of the housing 11 located downstream of the valve seat. Furthermore, the inner diameter of the protective sleeve 14 is the same as that of the inner valve seat 13, ensuring a stable flow rate when the fluid flows through the inner valve seat 13 and the protective sleeve 14.

[0095] Optionally, referring to Figures 1 and 7, the inner cavity also includes a pressure relief outlet channel 11e extending radially and connected to the other side of the fluid cavity 11a. A pressure relief valve 17 is provided on the side of the pressure relief outlet channel 11e away from the fluid cavity 11a. When the pressure in the inner cavity is too high, the pressure in the inner cavity can be discharged out of the throttle valve by opening the pressure relief valve to prevent safety accidents.

[0096] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention may be subjected to various simple modifications, including combining the specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A cage-type double-wedge throttle valve, characterized in that, Comprising: A housing (11), the housing including an inner cavity for fluid flow; A valve cover (7), the valve cover (7) being provided at the top of the housing (11), the valve cover (7) having an installation passage; A valve seat, the valve seat being provided in the inner cavity, the valve seat including an outer valve seat (16) and an inner valve seat (13), a plurality of flow holes (16b) being distributed on the peripheral wall of the outer valve seat (16), the outer valve seat (16) being provided in the inner cavity, the inner valve seat (13) being provided in the outer valve seat (16), and being located at the bottom of the outer valve seat (16) and axially offset from the flow holes (16b), so that the fluid in the inner cavity sequentially flows through the outer valve seat (16) and the inner valve seat (13); A valve core (12), the valve core (12) including two wedge-shaped surfaces (12b) and two cylindrical surfaces (12a) symmetrically arranged about the central axis, the cylindrical surfaces (12a) facing the direction in which the fluid flows into the inner cavity, the cylindrical surfaces (12a) being capable of fitting with the inner wall of the inner valve seat (13); and, A valve stem (21), one end of the valve stem (21) being connected to a driving device, and the other end passing through the installation passage and being connected to the valve core (12), the valve stem (21) being capable of driving the valve core (12) to reciprocate in the valve seat along the axial extension direction of the valve stem (21) under the drive of the driving device; The cage-type double-wedge throttle valve further includes a guide strip (10) provided in the installation passage and surrounding the valve stem (21), the guide strip (10) being capable of protecting and straightening the valve stem (21), and a first annular gap being formed between the guide strip (10) and the valve stem (21).

2. The cage-type double-wedge throttle valve according to claim 1, wherein The included angle formed by the center line of the wedge-shaped surface (12b) and the central axis is a wedge angle, and the range of the wedge angle is 5° - 30°.

3. The cage-type double-wedge throttle valve according to claim 2, wherein The range of the wedge angle is 10° - 20°.

4. The cage-type double-wedge throttle valve according to claim 1, wherein, The wedge-shaped surface (12b) is a convex surface.

5. The cage-type double-wedge throttle valve according to claim 1, characterized in that, The valve core (12) further includes two guiding surfaces (12c) symmetrically arranged about the central axis, the guiding surfaces (12c) being provided at one end of the wedge-shaped surface (12b) away from the valve stem (21), and the guiding surfaces (12c) being convex surfaces.

6. The cage-type double-wedge throttle valve according to claim 1, characterized in that, There is a gap between the valve stem (21) and the installation passage for the fluid in the inner cavity to flow in.

7. The cage-type double-wedge throttle valve according to claim 1, characterized in that, A counterbore (7a) is formed at one end of the installation passage close to the outer valve seat (16), and the top end of the outer valve seat (16) can extend into the counterbore (7a).

8. The cage-type double-wedge throttle valve according to claim 1, characterized in that, A sealing assembly is provided at one end of the installation passage away from the outer valve seat (16) to prevent fluid from flowing out through the gap between the valve stem (21) and the installation passage.

9. The cage-type double-wedge throttle valve according to claim 8, wherein, The sealing assembly includes a packing seal ring (18) provided in the gap between the valve stem (21) and the installation passage and a packing gland (5) for pressing the packing seal ring (18).

10. The cage-type double-wedge throttle valve according to claim 9, characterized in that, A second sealing ring (20) is installed between the packing seal ring (18) and the packing gland (5).

11. The cage-type double-wedge throttle valve according to any one of claims 1-10, characterized in that, The driving device includes an electric drive actuator (1), a rotating sleeve (4) rotatably connected to the electric drive actuator (1), a bearing seat (22) sleeved outside the rotating sleeve and threadedly connected to the valve cover (7), a bearing (3) disposed between the rotating sleeve (4) and the bearing seat (22), and a lead screw assembly (23) disposed inside the rotating sleeve (4). The lead screw assembly (23) includes a lead screw (23b) and a nut (23a) threadedly connected to the lead screw (23b). One end of the lead screw (23b) away from the nut (23a) is connected to the valve stem (21). Wherein, the electric drive actuator (1) is configured to drive the rotating sleeve (4) to rotate, driving the nut (23a) to rotate, so that the lead screw (23b) reciprocates along its axial extension direction.

12. The cage-type double-wedge throttle valve according to claim 11, characterized in that, It further includes an anti-rotation pin (6), and the anti-rotation pin (6) passes through the bearing seat (22) and abuts against the valve cover (7).

13. The cage-type double-wedge throttle valve according to claim 11, characterized in that, It further includes a limit pin (9). One end of the limit pin (9) abuts in a keyway (21a) on the valve stem (21), and the other end is fixedly connected to the installation channel. The fluid in the inner cavity can flow into the gap between the valve stem (21) and the installation channel through the keyway (21a).

14. The cage-type double-wedge throttle valve according to claim 1, wherein The inner cavity includes a fluid chamber (11a) axially extending and connected to the bottom of the installation channel, a fluid inlet channel (11b) radially extending and connected to one side of the fluid chamber (11a), and a fluid outlet channel (11d) axially extending and connected to the bottom of the fluid chamber (11a). Wherein, the diameter of the fluid chamber (11a) is larger than the diameters of the installation channel, the fluid inlet channel (11b), and the fluid outlet channel (11d). The lower end of the valve seat is partially inserted into the fluid outlet channel (11d).

15. The cage-type double-wedge throttle valve according to claim 14, characterized in that, It further includes a protective sleeve (14) disposed in the fluid outlet channel (11d), and the upper end of the protective sleeve (14) is joined to the lower end of the valve seat.

16. The cage-type double-wedge throttle valve according to claim 15, characterized in that, A first sealing ring (15) is provided between the upper end of the protective sleeve (14) and the lower end of the valve seat.

17. The cage-type double-wedge throttle valve according to claim 15, wherein, A seating step (11c) is formed in the fluid outlet channel (11d), and the protective sleeve (14) is stopped on the seating step (11c).

18. The cage-type double-wedge throttle valve according to claim 14, characterized in that, The inner cavity further includes a pressure relief outlet channel (11e) radially extending and connected to the other side of the fluid chamber (11a). A pressure relief valve (17) is provided on the side of the pressure relief outlet channel (11e) away from the fluid chamber (11a) to discharge the pressure in the inner cavity.

Images