Multistage step sleeve depressurization regulating valve

Abstract

The invention relates to the technical field of regulating valves, in particular to a multi-stage step sleeve depressurization regulating valve, a step type valve cage assembly is arranged in the depressurization regulating valve, and the step type valve cage assembly comprises a top disc, multiple layers of middle discs and a bottom disc which are sequentially stacked from top to bottom; the multiple layers of middle discs are connected and positioned through fixing pins, gaps are formed between the multiple layers of middle discs and the top disc and between the multiple layers of middle discs and the bottom disc, gaps are also formed between the multiple layers of middle discs and the top disc and between the multiple layers of middle discs and the bottom disc, and groove runners and expansion runners are formed between the multiple layers of middle discs and between the multiple layers of middle discs and the top disc and the bottom disc. The stepped valve cage assembly is formed by stacking the top disc, the multiple layers of middle discs and the bottom disc layer by layer, gaps are formed between the top disc, the multiple layers of middle discs and the bottom disc, and a groove flow channel and an expansion flow channel are formed between every two adjacent discs. Accurate speed control, progressive pressure reduction and phase change suppression of high-pressure-difference fluid are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of regulating valves, and particularly relates to a multistage stepped sleeve pressure-reducing regulating valve. BACKGROUND

[0002] In the field of industrial process control, regulating valves, as the core components of fluid control systems, are widely used in the petroleum, chemical, power, metallurgical and other industries. Under high pressure difference conditions, the pressure drop distribution of traditional regulating valves is too concentrated, which leads to a sharp increase in medium flow rate, and further causes serious cavitation phenomenon; this phenomenon can cause erosion damage to key components such as valve cages and valve seats, greatly shortening the service life of the valve, and in the high-pressure difference steam flow regulating scene in the fields of petroleum and chemical industry, thermal power generation, etc., this problem is particularly prominent.

[0003] The existing traditional single-seat and cage-type regulating valves are prone to cause local steam flow rate to reach the critical sound speed and trigger choked flow due to the single-stage / less-stage throttling of the valve core, which leads to an increase in regulating precision deviation, and the straight / curved flow channels of conventional labyrinth valves have defects such as uneven flow rate distribution, fast valve core erosion and wear, insufficient pressure drop dispersion under small opening throttling and large opening throttling under variable flow conditions. Therefore, a new type of valve core structure capable of realizing multistage micro pressure drop, full flow speed control and anti-erosion cavitation is needed to solve the above problems. SUMMARY

[0004] The purpose of the present application is to provide a multistage stepped sleeve pressure-reducing regulating valve, which solves the above-mentioned defects such as uneven valve flow rate distribution, fast valve core erosion and wear, and insufficient pressure drop dispersion under small opening throttling and large opening throttling under variable flow conditions.

[0005] To solve the above technical problems, the present application provides a multistage stepped sleeve pressure-reducing regulating valve, which is provided with a stepped valve cage assembly inside the pressure-reducing regulating valve, the stepped valve cage assembly includes a top disc, a plurality of intermediate discs and a bottom disc which are sequentially stacked from top to bottom, the plurality of intermediate discs are connected and positioned by fixing pins and have gaps therebetween, and the plurality of intermediate discs and the top disc and the bottom disc also have gaps therebetween and are fixed by fixing pins;

[0006] The bottom surface of the top disc is sequentially provided with a plurality of n-shaped grooves and a plurality of stepped circular cones from the inner ring to the outer ring, the diameters of the plurality of stepped circular cones gradually increase from the inner ring to the outer ring, and the heights of the plurality of stepped circular cones gradually decrease; the top surface of the bottom disc is sequentially provided with a plurality of u-shaped grooves and a plurality of stepped platforms from the inner ring to the outer ring, the heights of the plurality of stepped platforms gradually increase from bottom to top; the top surface structure of each intermediate disc is the same as that of the top surface of the bottom disc, and the bottom surface structure of each intermediate disc is the same as that of the bottom surface of the top disc;

[0007] The n-shaped grooves and multi-stage frustums on the bottom surface of the top disk correspond one-to-one with the U-shaped grooves and multi-stage steps on the top surface of the first layer of intermediate disks; the n-shaped grooves and multi-stage frustums between adjacent layers of intermediate disks also correspond one-to-one with the U-shaped grooves and multi-stage steps; the n-shaped grooves and multi-stage frustums on the bottom surface of the last layer of intermediate disks also correspond one-to-one with the U-shaped grooves and multi-stage steps of the bottom disk, so that grooved flow channels and expanding flow channels are formed between the multiple layers of intermediate disks and between them and each layer of the top and bottom disks.

[0008] Furthermore, a pressure plate is pressed onto the top of the top plate, the top surface of the top plate has a boss structure, and the bottom surface of the pressure plate has a groove for placing the boss.

[0009] Specifically, there are four locating pins between the intermediate disks and between them and the top and bottom disks. The four locating pins are located near the outer ring of the intermediate disk and are evenly distributed along its circumference.

[0010] Preferably, the gaps between the multiple layers of intermediate disks and between them and the top and bottom disks are equal, with a gap range of 2-5 mm.

[0011] Preferably, the gaps between the top disk and the first intermediate disk, the gaps between multiple intermediate disks, and the gap between the last intermediate disk and the bottom disk gradually decrease from top to bottom, with a gap range of 2-5 mm.

[0012] Specifically, the expansion coefficient of the expansion channel increases gradually, with the expansion coefficient ranging from 1.12 to 1.15.

[0013] Furthermore, the pressure reducing regulating valve also includes a regulating valve body and a valve cover, the valve cover being disposed on the top of the regulating valve body and fixed therebetween by bolts, and the stepped valve cage assembly being disposed within the regulating valve body.

[0014] Specifically, the inner and outer diameters of the top disk, the multi-layer intermediate disk, and the bottom disk are all the same.

[0015] The beneficial effects of the present invention: The stepped valve cage assembly of the present invention is composed of a top plate, multiple layers of middle plates and bottom plates with gaps between them, stacked one layer at a time. Through the three-dimensional collaborative design of "spatial layering + flow channel topology + energy dissipation", it can achieve precise speed control, gradual pressure reduction and suppression of phase change of high pressure differential fluid (such as steam).

[0016] In this invention, each layer of discs uses an n-shaped groove + U-shaped groove combination to form a grooved flow channel, plus a stepped expansion flow channel. This not only reduces the temperature of the medium, but also, through the layered design of the groove depth and the step height, the number of steps / grooves participating in throttling changes synchronously when the valve opening changes. This maintains fine throttling accuracy at low flow rates and disperses the flow velocity through more flow channels at high flow rates. It is particularly suitable for the "variable flow regulation" requirements of steam systems, avoiding blockage caused by excessively high local flow velocities at small openings.

[0017] The valve cage assembly of this invention is designed to enhance the valve's resistance to erosion and cavitation: after the high-pressure differential fluid steam enters the valve core, it expands with the change in pressure. The reciprocating flow channel formed by the interlayer groove flow channel and the stepped expansion flow channel allows the kinetic energy of the steam to be consumed multiple times, resulting in a lower erosion force on the valve core surface than conventional labyrinth valves. At the same time, the tortuous flow channel can disrupt the formation environment of cavitation bubbles, making it difficult for bubbles to accumulate during reciprocating turns, thus improving its adaptability to easily phase-change media such as saturated steam. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the pressure-reducing regulating valve of the present invention;

[0020] Figure 2 This is a partial enlarged schematic diagram of the stepped valve cage assembly of the pressure reducing regulating valve of the present invention.

[0021] Figure 3 This is a structural diagram of the stepped valve cage assembly of the pressure reducing regulating valve of the present invention.

[0022] Figure 4 This is a three-dimensional schematic diagram of another embodiment of the stepped valve cage assembly of the pressure reducing regulating valve of the present invention.

[0023] In the diagram: 1-top disc, 11-n-type groove, 12-multi-stage frustum, 2-middle disc, 3-bottom disc, 31-U-type groove, 32-multi-stage step, 4-fixed pin, 5-pressure plate, 6-regulating valve body, 7-valve cover, 8-groove flow channel, 9-expansion flow channel. Detailed Implementation

[0024] The technical solutions in the embodiments of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] In one specific embodiment of the present invention, such as Figures 1-3 As shown, a multi-stage stepped sleeve pressure reducing regulating valve is disclosed. The valve contains a stepped valve cage assembly, which includes a top disc 1, four intermediate discs 2, and a bottom disc 3 stacked sequentially from top to bottom. The inner and outer diameters of the top disc 1, the four intermediate discs 2, and the bottom disc 3 are all the same. The four intermediate discs are connected and positioned by fixing pins 4, with gaps between them. There are also gaps between the four intermediate discs 2 and the top and bottom discs 3, and they are respectively connected and fixed by fixing pins 4. There are four positioning pins 4 between each of the four intermediate discs 2 and between each of them and the top and bottom discs 3. These four positioning pins 4 are located near the outer circumference of the intermediate discs and are evenly distributed along their circumference. The gaps between the four intermediate discs 2 and between each of them and the top and bottom discs 3 are equal, with a gap range of 2-5 mm.

[0026] A pressure plate 5 is pressed onto the top of the top plate 1. The top surface of the top plate 1 has a boss structure, and the bottom surface of the pressure plate 5 has a groove for placing the boss. The bottom surface of the top plate 1 has five n-shaped grooves 11 and three-stage frustums 12 arranged sequentially from the inner circle to the outer circle. The diameter of the three-stage frustums 12 gradually increases from the inner circle to the outer circle, and the height of the frustums gradually decreases.

[0027] The top surface of the bottom disk 3 is provided with five U-shaped grooves 31 and three steps 32 in sequence from the inner circle to the outer circle. The height of the three steps 32 gradually increases from bottom to top. The top surface structure of each layer of the middle disk 2 is the same as the top surface structure of the bottom disk 3, and the bottom surface structure is the same as the bottom surface structure of the top disk 1.

[0028] The n-shaped grooves and three-stage frustums on the bottom surface of the top disk 1 correspond one-to-one with the U-shaped grooves and multi-stage steps on the top surface of the first layer of intermediate disk 3; the n-shaped grooves and multi-stage frustums between adjacent layers of intermediate disk 3 also correspond one-to-one with the U-shaped grooves and multi-stage steps; the n-shaped grooves and multi-stage frustums on the bottom surface of the last layer of intermediate disk 3 also correspond one-to-one with the U-shaped grooves and multi-stage steps of the bottom disk 3, so that grooved flow channels 8 and expanding flow channels 9 are formed between the multiple layers of intermediate disk 2 and between them and each layer of the top and bottom disks, and the expansion coefficient of the expanding flow channel increases step by step, with the expansion coefficient ranging from 1.12 to 1.15.

[0029] The pressure reducing regulating valve also includes a regulating valve body 6 and a valve cover 7. The valve cover 7 is disposed on the top of the regulating valve body 6 and is fixed to it by bolts. The stepped valve cage assembly is disposed inside the regulating valve body 6.

[0030] In another embodiment of the invention, such as Figure 4 As shown, the stepped valve cage assembly includes a top disc 1, four layers of intermediate discs 2 and a bottom disc 3 stacked sequentially from top to bottom. The four layers of intermediate discs are connected and positioned by fixing pins 4 and have gaps between them. There are also gaps between the four layers of intermediate discs 2 and the top discs 1 and the bottom discs 3, and they are respectively connected and fixed by fixing pins 4. The gaps between the four layers of intermediate discs 2 and between them and the top discs 1 and the bottom discs 3 are equal, and the gap range is 2-5 mm.

[0031] The bottom surface of the top disk 1 has three n-shaped grooves 11 and three-tiered frustums 12 arranged sequentially from the inner circle to the outer circle. The diameter of the three-tiered frustums 12 gradually increases from the inner circle to the outer circle, while the height of the frustums gradually decreases. The top surface of the bottom disk 3 has three U-shaped grooves 31 and three-tiered steps 32 arranged sequentially from the inner circle to the outer circle. The height of the three-tiered steps 32 gradually increases from bottom to top. The top surface structure of each intermediate disk 2 is the same as the top surface structure of the bottom disk 3, and the bottom surface structure is the same as the bottom surface structure of the top disk 1.

[0032] The n-shaped grooves and three-stage frustums on the bottom surface of the top disk 1 correspond one-to-one with the U-shaped grooves and multi-stage steps on the top surface of the first layer of intermediate disk 3; the n-shaped grooves and multi-stage frustums between adjacent layers of intermediate disk 3 also correspond one-to-one with the U-shaped grooves and multi-stage steps; the n-shaped grooves and multi-stage frustums on the bottom surface of the last layer of intermediate disk 3 also correspond one-to-one with the U-shaped grooves and multi-stage steps of the bottom disk 3, so that grooved flow channels 8 and expanding flow channels 9 are formed between the multiple layers of intermediate disk 2 and between them and each layer of the top and bottom disks, and the expansion coefficient of the expanding flow channel increases step by step, with the expansion coefficient ranging from 1.12 to 1.15.

[0033] In another embodiment of the present invention, the difference from other embodiments is that the gap between the top disk 1 and the first intermediate disk 2, the gap between the multiple intermediate disks 2, and the gap between the last intermediate disk 2 and the bottom disk 3 gradually decrease from top to bottom. The gap can be adjusted according to the size of the medium particles, and the preferred range is 2-5 mm.

[0034] The core design logic of the stepped valve cage assembly of this invention is to achieve "precise speed control, gradual pressure reduction, and phase change suppression" for high pressure differential fluids through a three-dimensional collaborative design of "spatial layering + flow channel topology + energy dissipation," which is particularly suitable for water vapor. Specifically, it can be broken down into three dimensions of deep logic:

[0035] I. Spatial layering and dynamic cross-sectional adaptation: Adaptive throttling logic of "opening-flow channel"

[0036] The depth and step height of the grooved flow channels in the valve cage assembly of the present invention are designed with layered differentiation, forming a "dynamically variable flow channel network" in conjunction with the valve opening:

[0037] Small opening condition: The valve core is raised only 1 to 3 layers of discs. At this time, only a few stepped flow channels at the bottom participate in throttling. The total cross-sectional area of ​​the flow channel is small, but the resistance of "reciprocating turning" can still disperse the pressure drop, avoiding the risk of blockage caused by "throttling and necking → sudden increase in flow velocity" under the traditional valve core small opening condition.

[0038] Large opening condition: The valve core is lifted to a higher height, and more layers of disc flow channels participate in the work. The total cross-sectional area of ​​the flow channels is expanded synchronously. At the same time, each layer of reciprocating flow channel still maintains an independent resistance node, which not only meets the demand for large flow rate, but also prevents the flow rate from getting out of control due to excessively wide flow channels.

[0039] Adaptability to steam: Steam systems often face "variable load regulation". This "opening-flow channel" adaptive design can keep the steam flow rate within a controllable range throughout the entire flow range, avoiding blockage caused by flow fluctuations.

[0040] II. Channel Topology: Resistance Field Design Based on "Reciprocating Twists and Turns + Hierarchical Nesting"

[0041] The structural flow channel design of this invention is a nested combination design of intralayer reciprocating flow and interlayer series flow. Intralayer reciprocating flow channel: a grooved flow channel and a stepped expansion flow channel are formed between adjacent disks. After the high pressure differential fluid vapor enters, it needs to complete the movement of "forward → turn → climb → turn again" in each layer. Each turn will generate local resistance due to the sudden change in the flow channel cross section, achieving a small pressure drop in a single step. Interlayer series stacking: after multiple layers of disks are stacked, the flow channels of the layers are connected to each other, forming a multi-level series resistance field, which has a good pressure reduction effect on the medium.

[0042] Adaptability to water vapor: The compressibility of steam increases as the pressure decreases. This "micro-pressure drop + multi-node" design ensures that the flow rate of each stage remains stable within the subcritical range, avoiding "expansion acceleration → flow rate exceeding limit" caused by excessive pressure drop in a single step.

[0043] III. Achieving Energy Dissipation and Phase Change Suppression: Thermodynamic Control of "Kinetic Energy Dispersion + Flow Field Homogenization"

[0044] The valve cage assembly of this invention, through the topological design of the flow channel, simultaneously achieves kinetic energy dissipation and flow field homogenization, thereby suppressing the phase change of water vapor.

[0045] Kinetic energy dispersion: The reciprocating flow channel formed by the interlayer grooved flow channel and the stepped expansion flow channel reduces the kinetic energy of the steam multiple times. Each turn converts some of the kinetic energy into heat energy, reducing the concentration of kinetic energy caused by the expansion and acceleration of the steam, and avoiding local pressure changes caused by excessive kinetic energy, which can induce steam condensation and phase change.

[0046] Flow field homogenization: The multi-layer stepped structure can break the concentrated flow of steam, so that the flow field is uniformly distributed in both the radial and axial directions, avoiding the occurrence of excessive velocity difference in local areas that causes gas-liquid two-phase stratification, thereby eliminating two-phase flow blockage caused by phase change.

[0047] Adaptability to water vapor: For saturated steam that is prone to phase change, this design of "kinetic energy dissipation + flow field homogenization" can maintain the dryness of the steam and avoid sudden changes in flow resistance formed by the liquid phase.

[0048] The above-disclosed embodiments are merely some preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A multi-stage stepped sleeve pressure reducing regulating valve, characterized in that, The pressure reducing regulating valve is provided with a stepped valve cage assembly. The stepped valve cage assembly includes a top plate (1), multiple layers of intermediate plates (2) and a bottom plate (3) stacked from top to bottom. The multiple layers of intermediate plates are connected and positioned by fixing pins (4) and there is a gap between them. There is also a gap between the multiple layers of intermediate plates (2) and the top plate (1) and the bottom plate (3) and they are respectively connected and fixed by fixing pins (4). The bottom surface of the top disk (1) is provided with a number of n-shaped grooves (11) and a multi-stage frustum (12) in sequence from the inner circle to the outer circle. The diameter of the multi-stage frustum (12) gradually increases from the inner circle to the outer circle, and the height of the frustum gradually decreases. The top surface of the bottom disk (3) is provided with a number of U-shaped grooves (31) and a multi-stage step (32) in sequence from the inner circle to the outer circle. The height of the multi-stage step (32) gradually increases from bottom to top. The top surface structure of each layer of the middle disk (2) is the same as the top surface structure of the bottom disk (3), and the bottom surface structure is the same as the bottom surface structure of the top disk (1). The n-shaped grooves and multi-stage frustums on the bottom surface of the top disk (1) correspond one-to-one with the U-shaped grooves and multi-stage steps on the top surface of the first layer of intermediate disks (3); the n-shaped grooves and multi-stage frustums between two adjacent layers of intermediate disks (3) also correspond one-to-one with the U-shaped grooves and multi-stage steps; the n-shaped grooves and multi-stage frustums on the bottom surface of the last layer of intermediate disks (3) also correspond one-to-one with the U-shaped grooves and multi-stage steps of the bottom disk (3), so that grooved flow channels (8) and expansion flow channels (9) are formed between the multiple layers of intermediate disks (2) and between them and each layer of the top and bottom disks.

2. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The top of the top plate (1) is pressed with a pressure plate (5), the top surface of the top plate (1) is a boss structure, and the bottom surface of the pressure plate (5) is provided with a groove for placing the boss.

3. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The number of positioning pins (4) between the intermediate disks (2) and between them and the top disk (1) and bottom disk (3) is four. The four positioning pins (4) are arranged close to the outer ring of the intermediate disk and are evenly distributed along its circumference.

4. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The gaps between the intermediate disks (2) and between them and the top disk (1) and bottom disk (3) are equal, with a gap range of 2-5 mm.

5. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The gaps between the top disk (1) and the first intermediate disk (2), the gaps between multiple intermediate disks (2), and the gaps between the last intermediate disk (2) and the bottom disk (3) gradually decrease from top to bottom, with a gap range of 2-5 mm.

6. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The expansion coefficient of the expansion channel increases gradually, and the expansion coefficient ranges from 1.12 to 1.

15.

7. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The pressure reducing regulating valve also includes a regulating valve body (6) and a valve cover (7). The valve cover (7) is located on the top of the regulating valve body (6) and is fixed to it by bolts. The stepped valve cage assembly is located inside the regulating valve body (6).

8. The multi-stage stepped sleeve pressure reducing regulating valve according to claim 1, characterized in that, The inner and outer diameters of the top disk (1), the multi-layer intermediate disk (2), and the bottom disk (3) are all the same.

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