Multi-stage pressure reducing valve

Abstract

The invention relates to the technical field of pressure reducing valves, in particular to a multi-stage pressure reducing valve which comprises a valve body, an inlet and an outlet are formed in the two sides of the valve body respectively, a valve seat is arranged in the valve body and located between the inlet and the outlet, a flow channel is formed in the valve seat and communicated with the inlet and the outlet, a valve element is in threaded connection with the valve body, and the valve element is in sliding fit with the flow channel. The valve seat is connected with a multi-stage pressure reducing cage, the multi-stage pressure reducing cage and the flow channel are coaxially arranged, the horizontal projection of the flow channel is located in the multi-stage pressure reducing cage, and an ejector block is installed at the upper end of the multi-stage pressure reducing cage in a sliding mode. The pressure change can be quickly responded, the flowing area of fluid can be timely adjusted, the problem that the output pressure is unstable due to the fact that a multi-stage pressure reducing valve is difficult to accurately adjust along with the pressure change in real time is solved, and the reliability and stability of the whole system are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure reducing valves, in particular to a multi-stage pressure reducing valve. BACKGROUND

[0002] The multi-stage pressure reducing valve is a pressure control device composed of multiple pressure reducing units. The multi-stage pressure reducing valve is composed of a valve body, a pressure reducing cage, a valve seat, a valve core, a diaphragm or a piston, a spring, an adjusting mechanism, a filter, and a pressure gauge interface. The pressure reducing cage is installed inside the valve body, which provides a stable installation space and support structure for the pressure reducing cage. The valve body is provided with inlet and outlet channels for fluid. After the fluid enters the inlet of the valve body, it flows through the pressure reducing cage according to the designed path. The multi-stage pressure reducing structure inside the pressure reducing cage gradually reduces the pressure of the fluid. Then the reduced fluid flows out through the outlet channel of the valve body. Through step-by-step pressure reduction and the use of multi-layer structure, the medium pressure is adjusted step by step, achieving precise control of the output pressure. It can meet the demand of high stability and precision of pressure. Compared with single-layer pressure reducing valve, it has more advantages in control accuracy, pressure regulating range and stability. In the fields of petroleum and chemical industry, power, natural gas transportation, etc., the multi-stage pressure reducing valve is often applied to pipeline systems, reaction kettles, steam power systems, etc.

[0003] However, due to changes in the flow rate, flow rate, resistance, height difference of the pipeline, and external environment, the actual pressure in the pipeline will change. In the prior art, it is difficult for the pressure reducing valve to accurately follow the pressure change in real time, resulting in unstable output pressure, affecting the normal operation of the system and the performance of the equipment, and even causing safety problems. For this problem, the prior art provides a solution, such as patent application No. CN202410954606.2, which provides a multi-stage pressure reducing gate valve for extreme pressure conditions. The patent provides the following technical solution: a first pressure reducing valve body and a second pressure reducing valve body, the first pressure reducing valve body includes a trigger mechanism, the surface of the trigger mechanism is provided with a flow dividing mechanism, the bottom of the flow dividing mechanism is provided with a connecting mechanism, the top of the flow dividing mechanism is provided with a pressure reducing mechanism, the trigger mechanism includes a rotating plate, the top of the rotating plate is fixedly connected with a rotating shaft, the side of the rotating plate is fixedly connected with an inclined block, the side of the rotating plate close to the inclined block is fixedly connected with a first spring. The gate valve includes a first pressure reducing valve body and a second pressure reducing valve body which can be detachably connected in series. It has higher pressure reducing efficiency and stability. Through the design of multi-stage pressure reducing structure, efficient pressure reduction is realized in high pressure environment, and flexible pressure regulating ability is realized, which can adapt to different working environments and ensure the safe and stable operation of the system. However, the multi-stage pressure reducing gate valve in the above-mentioned solution is composed of multiple valve bodies and multiple components, which has a complex structure and cannot be adapted to the pressure reducing cage. In addition, this solution has high manufacturing cost, large installation space requirement, and difficult maintenance. SUMMARY

[0004] The purpose of the present application is to provide a multi-stage pressure reducing valve to solve the problem that the multi-stage pressure reducing valve is difficult to follow the pressure change in real time and accurately, resulting in unstable output pressure, affecting the normal operation of the system and the performance of the equipment, and even causing safety problems.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] A multi-stage pressure reducing valve, comprising a valve body, an inlet and an outlet are respectively arranged on both sides of the valve body, a valve seat is arranged in the valve body, the valve seat is located between the inlet and the outlet, a flow channel is arranged on the valve seat, the flow channel is in communication with the inlet and the outlet, a valve core is threadedly connected to the valve body, the valve core is in sliding fit with the flow channel, a multi-stage pressure reducing cage is connected to the valve seat, the multi-stage pressure reducing cage is coaxially arranged with the flow channel, and the horizontal projection of the flow channel is located in the multi-stage pressure reducing cage, characterized in that a top block is slidably arranged at the upper end of the multi-stage pressure reducing cage, guide grooves are arranged on the front and rear side walls of the top block, the guide grooves are inclined, the height of the guide grooves in the vertical direction decreases from the inlet to the outlet, a first sliding groove is horizontally arranged on the valve body, one end of the first sliding groove is in communication with the inner wall of the valve body, and the communication part between the first sliding groove and the inner wall of the valve body is located between the valve seat and the inlet, a sliding rod is slidably arranged in the first sliding groove, one end of the sliding rod extends out of the first sliding groove and is in sliding fit with the guide groove, and an extension spring is connected to the top end of the top block, the upper and lower ends of the extension spring are respectively connected to the top block and the valve body.

[0007] In operation, fluid comes to the inlet of the valve body through the pipeline, and the valve core is rotated to separate the valve core from the flow channel, so that the fluid comes to the multi-stage pressure reducing cage through the flow channel and is reduced in pressure by the multi-stage pressure reducing cage, and then flows to the outlet, when the pressure of the fluid at the inlet increases, the pressure of the fluid acts on one end of the sliding rod, so that the sliding rod slides in the first sliding groove, the other end of the sliding rod slides in the guide groove on the side wall of the top block, the sliding rod moves from the high point of the guide groove to the low point, and then pushes the top block to slide upward, at this time, the extension spring is compressed, and the working area of the multi-stage pressure reducing cage through which the fluid flows increases, when the pressure of the fluid decreases, the elastic potential energy of the extension spring is released, and the top block is pushed to slide downward in the second sliding groove until the pressure at the upper and lower ends of the top block is balanced, and the top block stops moving, at this time, the working area of the multi-stage pressure reducing cage through which the fluid flows decreases, by the pilot design of the top block on the multi-stage pressure reducing valve following the change of the inlet pressure, and by the direct action of the fluid pressure on the sliding rod, the pressure change can be quickly responded, the accurate adjustment of the flow rate is realized by the accurate fit of the guide groove and the sliding rod, the inlet pressure is monitored in real time, the working area of the fluid is adjusted in time, the outlet pressure is effectively stabilized, the problem that the multi-stage pressure reducing valve is difficult to follow the pressure change in real time and accurately is avoided, the problem that the output pressure is unstable is solved, and the reliability and stability of the entire system are ensured.

[0008] Preferably, a second sliding groove is formed in the valve body, the second sliding groove is in sliding fit with the top block, the inner side wall of the second sliding groove and the top wall of the top block form a flat compression cavity, a through pipe is arranged in the valve body, the flat compression cavity is in communication with the inner wall of the valve body through the through pipe, the through pipe is tangentially arranged with the side wall of the flat compression cavity.

[0009] Fluids flow into the inlet of the valve body through the pipeline, part of the fluids flow to the flat compression cavity through the through pipe, when the fluids flow into the flat compression cavity, the pressure in the flat compression cavity increases, and then the top block is pushed to slide downward in the second sliding groove, the extension spring is stretched, and the process stops until the top block abuts against the upper end surface of the multi-stage pressure reduction cage, when the valve core is opened, the fluids flow into the multi-stage pressure reduction cage through the flow channel, the fluids in the multi-stage pressure reduction cage push the top block to slide upward in the second sliding groove, the extension spring is squeezed, and the process stops until the pressure at the upper and lower ends of the top block is balanced, the top block stops moving, through the design of the flat compression cavity and the extension spring, the impact force of the fluids on the top block when the valve core is opened can be buffered, and the force balance on both sides of the top block is ensured, displacement or shaking of the top block due to fluid impact is avoided, the stability of the top block is improved, and the stability of the output pressure is ensured.

[0010] Further, when the fluids flow into the flat compression cavity, the fluids flow in the tangential direction of the side wall of the flat compression cavity, the tangential inflow makes the fluids do circular motion along the wall surface of the flat compression cavity, the pressure can be more evenly distributed on the wall surface of the cavity, the distribution of the fluids in the cavity is more uniform, the local pressure peak is reduced, the local pressure is prevented from being too high or too low, and the fluids are prevented from colliding violently with the cavity at the inlet, so that the risk of equipment damage caused by pressure impact and uneven pressure is reduced.

[0011] Preferably, the flow channel comprises a primary channel and a secondary channel, the primary channel is located between the secondary channel and the multi-stage pressure reduction cage, a plurality of paddles are installed in the primary channel, the plurality of paddles are circumferentially and uniformly arranged around the primary channel, and the secondary channel is in sliding fit with the valve core.

[0012] The valve core is rotated to be separated from the secondary channel in the flow channel, the fluids flow into the multi-stage pressure reduction cage through the flow channel, in the process, the fluids flow through the paddles in the primary channel, so that the fluids rotate, the rotating fluids can better uniformly arrange the pressure in the multi-stage pressure reduction cage, avoid that the pressure imbalance causes the pressure reduction process of the fluids in the multi-stage pressure reduction cage to be unstable, and ensure that the uniform and gradual pressure reduction is realized according to the design requirements, the stability of the output pressure is ensured, the direct impact of the fluids on the inner wall of the multi-stage pressure reduction cage is reduced, the direct impact and wear of the inner wall are reduced, structural damage such as rupture and perforation of the multi-stage pressure reduction cage due to local excessive wear is avoided, and the service life of the equipment is prolonged.

[0013] Preferably, the multi-stage pressure reduction cage comprises a first-stage pressure reduction cylinder and a second-stage pressure reduction cylinder, the first-stage pressure reduction cylinder and the second-stage pressure reduction cylinder are coaxially arranged, and the first-stage pressure reduction cylinder is located in the second-stage pressure reduction cylinder, a plurality of first-stage through holes and second-stage through holes are uniformly arranged on the first-stage pressure reduction cylinder and the second-stage pressure reduction cylinder respectively, the through section of the first-stage through hole and the second-stage through hole is rectangular, the first-stage through hole and the second-stage through hole are arranged in a staggered manner, a plurality of adjacent first-stage through holes in the radial direction are arranged in a staggered manner, and the upper end face and the lower end face of the adjacent first-stage through holes are flush, a plurality of adjacent second-stage through holes in the radial direction are arranged in a staggered manner, and the upper end face and the lower end face of the adjacent second-stage through holes are flush.

[0014] When the fluid in the first-stage pressure reduction cylinder flows to the inner wall of the second-stage pressure reduction cylinder through the first-stage hole, the fluid on the inner wall of the second-stage pressure reduction cylinder flows to the outlet through the second-stage hole, in the process, when the fluid enters the first-stage pressure reduction cylinder and flows through the first-stage hole, the cross section through which the fluid flows becomes smaller, according to Bernoulli's principle, the flow rate of the fluid increases, and the pressure energy is converted into kinetic energy, thereby realizing the first pressure reduction, when the fluid collides with the inner wall of the second-stage pressure reduction cylinder, part of the kinetic energy of the fluid is converted into heat energy and other forms of energy dissipation, thereby realizing the second pressure reduction, when the fluid enters the second-stage pressure reduction cylinder and flows through the second-stage hole, the cross section through which the fluid flows becomes smaller, according to Bernoulli's principle, the flow rate of the fluid increases, and the pressure energy is converted into kinetic energy, thereby realizing the third pressure reduction, thereby obtaining the fluid after pressure reduction, and the upper end face and the lower end face of the adjacent first-stage through hole and second-stage through hole are flush, the area change of the fluid flow remains consistent during the up-down movement of the top block, avoiding the pressure fluctuation during the pressure reduction process, which causes the output pressure of the multi-stage pressure reduction cage to be unable to maintain at a stable value, affecting the pressure reduction effect, and ensuring the stability of the output pressure.

[0015] Preferably, a plurality of support blocks are uniformly arranged on the outer wall of the first-stage pressure reduction cylinder, the cross section of the support block is rhombic, the side of the support block away from the first-stage pressure reduction cylinder is in contact with the inner wall of the second-stage pressure reduction cylinder, the support block is located between adjacent first-stage through holes in the staggered direction, and the center line of the support block passes through the center of the adjacent first-stage through hole.

[0016] When the fluid in the first-stage pressure reduction cylinder flows to the inner wall of the second-stage pressure reduction cylinder through the first-stage hole, the fluid spreads from the first-stage hole to the surrounding, and the fluid in the staggered direction will appear convection, causing the fluid to appear turbulent flow phenomenon, and the turbulent flow is uncertain, making the flow of the fluid between the inner wall of the second-stage pressure reduction cylinder and the first-stage pressure reduction cylinder become uneven, and some pressure reduction holes may have larger flow rate while other pressure reduction holes have smaller flow rate, causing the fluid to be unable to realize smooth and gradual pressure reduction according to the design requirements, the arrangement of the support block can guide and block the fluid in the staggered direction, ensuring the stability of the output pressure, and under the action of the side wall of the support block, the fluid flows to the second-stage hole, avoiding the turbulent flow of the fluid.

[0017] Preferably, three friction rings are coaxially arranged in the top block, the three friction rings are arranged in staggered positions between the first pressure reducing cylinder and the second pressure reducing cylinder, and the friction rings are in sliding connection with the side walls of the first pressure reducing cylinder and the second pressure reducing cylinder. The friction rings are made of any one of tungsten carbide, titanium carbide, high manganese steel, and white cast iron.

[0018] In terms of structural design, the three friction rings are arranged in coaxial staggered positions, which expands the contact area with the side walls of the first pressure reducing cylinder and the second pressure reducing cylinder, so that the pressure on the top block is evenly distributed on multiple contact surfaces, avoiding the problem of excessive local friction caused by single-point contact. In terms of material properties, the use of materials with high hardness and strong wear resistance such as tungsten carbide, titanium carbide, high manganese steel, and white cast iron can significantly reduce the degree of wear when the friction ring slides in contact with the cylinder wall. The low friction coefficient of these materials can effectively reduce the resistance between the contact surfaces, avoiding the problem of jamming or movement delay of the top block due to excessive friction, and ensuring that the top block can slide up and down quickly and smoothly during pressure adjustment.

[0019] Preferably, a limiting ring is arranged in the flat pressure chamber, the distance from the lower end surface of the support part to the upper end surface of the top block is equal to the height of the guide groove in the vertical direction, and the through pipe is located above the limiting ring.

[0020] When the valve core has not been opened, and the pressure of the fluid in the pipeline suddenly changes due to rapid closing of the valve or other factors, part of the fluid flows to the first sliding groove and acts on one end of the sliding rod, causing the sliding rod to slide in the first sliding groove and the other end of the sliding rod to slide in the guide groove on the side wall of the top block. The sliding rod moves from the high point of the guide groove to the low point, thereby pushing the top block to slide upward in the second sliding groove. In the process, the extension spring is compressed. Due to the large impact force of the top block, the extension spring may be subjected to a pressure exceeding its elastic limit, causing cracks or even breakage of the extension spring. By arranging the limiting ring, the upper end surface of the top block contacts the lower end surface of the limiting ring during the upward movement of the top block, and the support part provides a rigid support to the top block, preventing the top block from moving upward further. This directly limits the compression stroke of the extension spring, ensuring that the extension spring will not be further compressed due to excessive displacement of the top block. This avoids the problem of the spring being subjected to a pressure exceeding its elastic limit, causing cracks or even breakage of the spring, and ensures the normal operation of the equipment.

[0021] Preferably, the limiting ring includes a support part and a shock-absorbing part, the shock-absorbing part is located on the side of the limiting ring close to the top block, and the shock-absorbing part is made of a flexible material.

[0022] The damping part is made of rubber, has good elasticity and flexibility, through the setting of the damping part, the direct impact of the top block on the supporting part is avoided, the damage of the limiting ring is avoided, the top block loses the limiting of the limiting ring, the limiting ring excessively extrudes the expansion spring, the problem that the spring appears cracks or even breaks and fails is solved, and the structural integrity of the top block and the supporting part is protected.

[0023] Compared with the prior art, the beneficial effects of the present application are:

[0024] 1、The present application adopts the pilot design of the top block on the multistage pressure reducing valve following the change of the inlet pressure, relies on the direct action of the fluid pressure on the slide rod, can quickly respond to the pressure change, realizes the accurate adjustment of the flow by the accurate cooperation of the guide groove and the slide rod, monitors the inlet pressure in real time, adjusts the fluid working area in time, effectively stabilizes the outlet pressure, avoids the problem that the multistage pressure reducing valve is difficult to accurately follow the pressure change for adjustment in real time, causes the unstable output pressure, and guarantees the reliability and stability of the whole system.

[0025] 2、The present application is designed by the flat pressure cavity and the expansion spring, can buffer the impact force of the fluid on the top block when the valve core is opened, ensures the force balance on both sides of the top block at the same time, avoids the displacement or shaking of the top block due to the impact of the fluid, improves the stability of the top block, and guarantees the stability of the output pressure.

[0026] 3、The present application is designed by the first through hole and the second through hole, realizes the three times of pressure reduction of the fluid, at the same time, the upper end face and the lower end face of the first through hole and the second through hole are flush, the area change of the fluid flow keeps continuity during the up-down movement of the top block, avoids the pressure fluctuation during the pressure reduction process, causes the output pressure of the multistage pressure reducing cage to be unable to keep at the set stable value, affects the pressure reduction effect, guarantees the stability of the output pressure. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is an overall structure axial section view of the multistage pressure reducing valve;

[0028] Figure 2 It is a full section view of the multistage pressure reducing valve;

[0029] Figure 3 It is Figure 1 A local enlarged view of the position A in the figure;

[0030] Figure 4 It is Figure 2 A local enlarged view of the position B in the figure;

[0031] Figure 5 It is an explosion schematic view of the multistage pressure reducing cage, the valve core, the top block, the expansion spring and the slide rod.

[0032] In the figure: 1, valve body; 11, inlet; 12, outlet; 13, valve seat; 131, flow channel; 132, primary channel; 133, secondary channel; 14, valve core; 15, through pipe; 16, No. 1 sliding groove; 17, sliding rod; 18, No. 2 sliding groove; 19, flat compression cavity; 2, multi-stage pressure reduction cage; 21, primary pressure reduction cylinder; 22, secondary pressure reduction cylinder; 23, No. 1 through hole; 24, No. 2 through hole; 25, support block; 3, top block; 31, guide groove; 32, friction ring; 4, telescopic spring; 5, paddle; 6, limiting ring; 61, support part; 62, shock absorbing part. DETAILED DESCRIPTION

[0033] Referring to Figures 1 to 5 The present application provides a multi-stage pressure reduction valve, and the technical scheme is as follows:

[0034] A multi-stage pressure reduction valve, comprising a valve body 1, the valve body 1 is provided with an inlet 11 and an outlet 12 on both sides respectively, the valve body 1 is provided with a valve seat 13 inside, the valve seat 13 is located between the inlet 11 and the outlet 12, the valve seat 13 is provided with a flow channel 131, the flow channel 131 is communicated with the inlet 11 and the outlet 12, the valve body 1 is provided with a valve core 14 which is screwed, the valve core 14 is in sliding fit with the flow channel 131, the valve seat 13 is connected with a multi-stage pressure reduction cage 2, the multi-stage pressure reduction cage 2 is coaxially arranged with the flow channel 131, the vertical projection of the flow channel 131 is located in the multi-stage pressure reduction cage 2, the top block 3 is slidingly installed at the upper end of the multi-stage pressure reduction cage 2, the guide grooves 31 are provided on the front and back sidewalls of the top block 3, the guide grooves 31 are obliquely arranged, the height of the guide grooves 31 in the vertical direction decreases from the inlet 11 to the outlet 12, the valve body 1 is horizontally provided with a No. 1 sliding groove 16, one end of the No. 1 sliding groove 16 is communicated with the inner wall of the valve body 1, and the communication part of the No. 1 sliding groove 16 with the inner wall of the valve body 1 is located between the valve seat 13 and the inlet 11, the sliding rod 17 is slidingly installed in the No. 1 sliding groove 16, one end of the sliding rod 17 extends out of the No. 1 sliding groove 16 and is in sliding fit with the guide grooves 31, the telescopic spring 4 is connected with the top end of the top block 3, and the upper and lower ends of the telescopic spring are connected with the top block and the valve body respectively.

[0035] Referring to Figures 1 to 4 The valve body 1 is provided with a No. 2 sliding groove 18, the No. 2 sliding groove 18 is in sliding fit with the top block 3, the inner sidewall of the No. 2 sliding groove 18 and the top wall of the top block 3 form a flat compression cavity 19, the valve body 1 is provided with a through pipe 15, the flat compression cavity 19 is communicated with the inner wall of the valve body 1 through the through pipe 15, the communication part of the through pipe 15 with the inner wall of the valve body 1 is located between the valve seat 13 and the inlet 11, and the through pipe 15 is tangentially arranged with the sidewall of the flat compression cavity 19; the limiting ring 6 is arranged in the flat compression cavity 19, the limiting ring 6 comprises a support part 61 and a shock absorbing part 62, the shock absorbing part 62 is located on the side of the limiting ring 6 close to the top block 3, the shock absorbing part 62 is made of flexible material, the distance from the lower end surface of the support part 61 to the upper end surface of the top block 3 is equal to the height of the guide grooves 31 in the vertical direction, and the through pipe 15 is located above the limiting ring 6.

[0036] Please refer to Figures 1 to 5 , the flow channel 131 includes a primary channel 132 and a secondary channel 133, the primary channel 132 is located between the secondary channel 133 and the multi-stage pressure reduction cage 2, a plurality of paddles 5 are installed in the primary channel 132, the plurality of paddles 5 are circumferentially distributed around the primary channel 132, and the secondary channel 133 is in sliding fit with the valve core 14; the multi-stage pressure reduction cage 2 includes a primary pressure reduction cylinder 21 and a secondary pressure reduction cylinder 22, the primary pressure reduction cylinder 21 and the secondary pressure reduction cylinder 22 are coaxially arranged, the primary pressure reduction cylinder 21 is located in the secondary pressure reduction cylinder 22, a plurality of first through holes 23 and a plurality of second through holes 24 are uniformly formed in the primary pressure reduction cylinder 21 and the secondary pressure reduction cylinder 22, respectively, the through section of the first through hole 23 and the second through hole 24 is in a rectangular shape, the first through hole 23 and the second through hole 24 are arranged in a staggered manner, a plurality of adjacent first through holes 23 in the radial direction are arranged in a staggered manner, the upper end surface and the lower end surface of the adjacent first through holes 23 are flush, a plurality of adjacent second through holes 24 in the radial direction are arranged in a staggered manner, and the upper end surface and the lower end surface of the adjacent second through holes 24 are flush; a plurality of support blocks 25 are uniformly distributed on the outer wall of the primary pressure reduction cylinder 21, the cross section of the support block 25 is in a rhombus shape, the side of the support block 25 away from the primary pressure reduction cylinder 21 is in abutment with the inner wall of the secondary pressure reduction cylinder 22, the support block 25 is located between the adjacent first through holes 23 in the staggered direction, and the center line of the support block 25 penetrates the center of the adjacent first through hole 23; three coaxially arranged friction rings 32 are installed in the top block 3, the three friction rings 32 are arranged in a staggered manner between the primary pressure reduction cylinder 21 and the secondary pressure reduction cylinder 22, and the friction ring 32 is in sliding connection with the two side walls of the primary pressure reduction cylinder 21 and the secondary pressure reduction cylinder 22, the friction ring 32 is made of tungsten carbide material, which has extremely high hardness and excellent wear resistance.

[0037] Working principle: please refer to Figures 1 to 5 , when working, the fluid flows into the inlet 11 of the valve body 1 through the pipeline, at this time, the fluid is blocked by the valve seat 13 and the valve core 14 and cannot flow to the outlet 12, at this time, part of the fluid flows to the flat pressure cavity 19 through the through pipe 15, when flowing into the flat pressure cavity 19, the fluid flows in the tangential direction of the side wall of the flat pressure cavity 19, the tangential direction of the flowing fluid in the flat pressure cavity 19 forms a rotating flow, which can make the distribution of the fluid in the cavity more uniform, avoid the situation that the local pressure is too high or too low, with the inflow of the fluid, the pressure in the flat pressure cavity 19 increases, thereby pushing the top block 3 to slide downward in the second sliding groove 18 until the top block 3 abuts against the upper end surface of the multi-stage pressure reduction cage 2 , the retractable spring 4 is stretched, The sliding rod 17 slides in the first sliding groove 16 under the action of the guide groove 31 on the top block 3 and slides to the highest point of the guide groove 31.

[0038] When the pressure of the fluid in the pipeline is suddenly changed due to the rapid closing of the valve or other factors, part of the fluid flows to the first chute 16 and acts on one end of the sliding rod 17, so that the sliding rod 17 slides in the first chute 16, and the other end of the sliding rod 17 slides in the guide groove 31 on the side wall of the top block 3, the sliding rod 17 moves from the high point of the guide groove 31 to the low point, and then pushes the top block 3 to slide upward in the second chute 18, in the process, the telescopic spring 4 is compressed, but due to the large impact force of the top block 3, the telescopic spring 4 may be compressed beyond its elastic limit, causing cracks or even breakage of the telescopic spring 4. Therefore, by arranging the limiting ring 6, in the process of the upward movement of the top block 3, the upper end surface of the top block 3 contacts and extrudes the shock absorbing part 62 on the limiting ring 6 until the upper end surface of the top block 3 contacts the supporting part 61 on the limiting ring 6, the supporting part 61 provides a rigid support for the top block 3, preventing the top block 3 from moving upward, directly limiting the compression stroke of the telescopic spring 4, and ensuring that the telescopic spring 4 will not be further compressed and damaged due to excessive displacement of the top block 3.

[0039] When the fluid needs to be decompressed, the valve core 14 is rotated to separate the valve core 14 from the secondary channel 133 in the flow channel 131, and the fluid passes through the flow channel 131 to enter the multi-stage decompression cage 2. In the process, when the fluid flows through the paddle 5 in the primary channel 132, the fluid is rotated, and the rotating fluid can better uniformly distribute the pressure in the multi-stage decompression cage 2, while reducing the direct impact of the fluid on the inner wall of the decompression cage. When the fluid fills the primary decompression cylinder 21, the top block 3 is pushed to slide upward in the second chute 18 until the pressure at the upper and lower ends of the top block 3 is balanced, and the top block 3 stops moving. In the process, the telescopic spring 4 is compressed, and the sliding rod 17 slides in the first chute 16 under the action of the guide groove 31 on the top block 3. At this time, the fluid in the primary decompression cylinder 21 flows to the inner wall of the secondary decompression cylinder 22 through the primary channel 132, and the fluid on the inner wall of the secondary decompression cylinder 22 flows to the outlet 12 through the secondary channel 133. In the process, when the fluid enters the primary decompression cylinder 21 and flows through the primary channel 132, the cross-sectional area of the fluid flow decreases, according to Bernoulli's principle, the flow rate of the fluid increases, and the pressure energy is converted into kinetic energy, thereby realizing the first pressure reduction. When the fluid collides with the inner wall of the secondary decompression cylinder 22, part of the kinetic energy of the fluid is converted into heat energy and other forms of energy dissipation, thereby realizing the second pressure reduction. When the fluid enters the secondary decompression cylinder 22 and flows through the secondary channel 133, the cross-sectional area of the fluid flow decreases, according to Bernoulli's principle, the flow rate of the fluid increases, and the pressure energy is converted into kinetic energy, thereby realizing the third pressure reduction, and then obtaining the decompressed fluid.

[0040] In the pressure reducing process, when the pressure of the fluid in the inlet 11 of the valve body 1 increases due to the rapid closing of the valve or other factors, the pressure of the fluid acts on one end of the slide rod 17, causing the slide rod 17 to slide in the first slide groove 16, the other end of the slide rod 17 slides in the guide groove 31 on the side wall of the top block 3, and pushes the top block 3 to slide upward in the second slide groove 18. At this time, the working area of the first-stage flow passage 132 and the second-stage flow passage 133 through which the fluid flows increases, when the pressure of the fluid decreases, the elastic potential energy of the extension spring 4 is released, and pushes the top block 3 to slide downward in the second slide groove 18, until the pressure at the upper and lower ends of the top block 3 is balanced, the top block 3 stops moving, at this time, the working area of the first-stage flow passage 132 and the second-stage flow passage 133 through which the fluid flows decreases, by adjusting the working area of the fluid, the pressure at the outlet 12 is kept stable.

[0041] The above describes one specific embodiment of the present application in detail in combination with the drawings, but the present application is not limited to the above described embodiment. For those skilled in the art, various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and ideas of the present application, which should still fall within the protection scope of the present application.

Claims

1. A multi-stage pressure reducing valve, comprising a valve body (1), wherein an inlet (11) and an outlet (12) are respectively provided on both sides of the valve body (1), a valve seat (13) is provided in the valve body (1), the valve seat (13) is located between the inlet (11) and the outlet (12), a flow channel (131) is provided on the valve seat (13), the flow channel (131) communicates with the inlet (11) and the outlet (12), a valve core (14) is threadedly connected to the valve body (1), the valve core (14) and the flow channel (131) are slidably matched, a multi-stage pressure reducing cage (2) is connected to the valve seat (13), the multi-stage pressure reducing cage (2) and the flow channel (131) are coaxially arranged, and the vertical projection of the flow channel (131) is located in the multi-stage pressure reducing cage (2), characterized in that The upper end of the multi-stage pressure-reducing cage (2) is slidably mounted with a top block (3), and guide grooves (31) are provided on the front and rear side walls of the top block (3). The guide grooves (31) are inclined, and the height of the guide grooves (31) in the vertical direction decreases from the inlet (11) to the outlet (12). A first slide groove (16) is horizontally provided on the valve body (1), and one end of the first slide groove (16) is connected to the inner wall of the valve body (1), and the connection point between the first slide groove (16) and the inner wall of the valve body (1) is located between the valve seat (13) and the inlet (11). A slide rod (17) is slidably mounted in the first slide groove (16), and one end of the slide rod (17) extends out of the first slide groove (16) and slidably cooperates with the guide groove (31). The top end of the top block (3) is connected with a telescopic spring (4), and the upper and lower ends of the telescopic spring (4) are respectively connected to the top block (3) and the valve body (1).

2. A multi-stage pressure reducing valve according to claim 1, characterized in that: A second slide groove (18) is provided in the valve body (1), and the second slide groove (18) is slidably matched with the top block (3). The inner side wall of the second slide groove (18) and the top wall of the top block (3) form a pressure-equalizing chamber (19). A through pipe (15) is provided in the valve body (1), and the pressure-equalizing chamber (19) is connected to the inner wall of the valve body (1) through the through pipe (15). The connection point between the through pipe (15) and the inner wall of the valve body (1) is located between the valve seat (13) and the inlet (11), and the through pipe (15) is tangent to the side wall of the pressure-equalizing chamber (19).

3. A multi-stage pressure reducing valve according to claim 1, characterized in that: The flow channel (131) includes a primary channel (132) and a secondary channel (133), wherein the primary channel (132) is located between the secondary channel (133) and the multi-stage pressure reduction cage (2), and a plurality of blades (5) are installed in the primary channel (132), and the plurality of blades (5) are evenly distributed around the axis of the primary channel (132), and the secondary channel (133) is in sliding cooperation with the valve core (14).

4. A multi-stage pressure reducing valve according to claim 3, characterized in that: The multi-stage pressure reducing cage (2) includes a first-stage pressure reducing cylinder (21) and a second-stage pressure reducing cylinder (22), wherein the first-stage pressure reducing cylinder (21) and the second-stage pressure reducing cylinder (22) are coaxially arranged, and the first-stage pressure reducing cylinder (21) is located inside the second-stage pressure reducing cylinder (22), and the first-stage pressure reducing cylinder (21) and the second-stage pressure reducing cylinder (22) are respectively and evenly provided with a plurality of No. 1 through holes (23) and No. 2 through holes (24), the through cross-sections of the No. 1 through holes (23) and the No. 2 through holes (24) are rectangular, the No. 1 through holes (23) and the No. 2 through holes (24) are staggered, and the plurality of No. 1 through holes (23) adjacent in the radial direction are staggered, and the upper end faces and lower end faces of the adjacent No. 1 through holes (23) are flush, and the plurality of No. 2 through holes (24) adjacent in the radial direction are staggered, and the upper end faces and lower end faces of the adjacent No. 2 through holes (24) are flush.

5. A multi-stage pressure reducing valve according to claim 4, characterized in that: A plurality of support blocks (25) are evenly distributed on the outer wall of the first-stage pressure-reducing cylinder (21), and the cross-section of the support blocks (25) is rhombus-shaped. The side of the support blocks (25) away from the first-stage pressure-reducing cylinder (21) abuts against the inner wall of the second-stage pressure-reducing cylinder (22). The support blocks (25) are located between adjacent No. 1 through holes (23) in a staggered direction, and the center line of the support blocks (25) passes through the center of the adjacent No. 1 through holes (23).

6. The multi-stage pressure reducing valve according to claim 4, characterized in that: Three coaxially arranged friction rings (32) are installed in the top block (3). The three friction rings (32) are staggered with the first-stage pressure-reducing cylinder (21) and the second-stage pressure-reducing cylinder (22). The friction rings (32) are slidably connected to the side walls of the first-stage pressure-reducing cylinder (21) and the second-stage pressure-reducing cylinder (22). The friction rings (32) are made of any one of tungsten carbide, titanium carbide, high manganese steel, and white cast iron.

7. The multi-stage pressure reducing valve according to claim 2, characterized in that: A limit ring (6) is provided in the equalizing and pressure-smoothing cavity (19), and the distance between the lower end surface of the limit ring (6) and the upper end surface of the top block (3) is equal to the height in the vertical direction of the guide groove (31), and the through pipe (15) is located above the limit ring (6).

8. The multi-stage pressure reducing valve according to claim 7, characterized in that: The limiting ring (6) comprises a supporting portion (61) and a vibration-absorbing portion (62). The vibration-absorbing portion (62) is located on a side of the limiting ring (6) close to the top block (3). The vibration-absorbing portion (62) is made of a flexible material.

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