High-pressure-difference anti-scouring low-noise stop valve

Abstract

The invention belongs to the field of valves, and particularly relates to a high-pressure-difference anti-scouring low-noise stop valve which comprises a valve body, a valve cover, a valve seat, a valve rod and a valve clack, the valve body is provided with a valve cavity, the valve body is provided with a liquid inlet channel and a liquid outlet channel which are communicated with the valve cavity, and the valve seat is provided with a valve seat hole communicated with the liquid inlet channel. The valve sleeve is provided with a valve sleeve hole communicated with the valve seat hole, the valve clack is arranged on the valve rod in a linkage mode and matched with the valve sleeve in a sealing mode, one end of the valve clack is provided with a conical surface sealing portion matched with the valve seat hole in a sealing mode, and a protruding ring sealing portion matched with the valve sleeve in a sealing mode is arranged at the position, corresponding to the position between the conical surface sealing portion and the valve sleeve hole, of the valve clack. A pressure reducing cavity A, a pressure reducing cavity B and a pressure reducing cavity C which are sequentially communicated are formed in the valve cavity, the pressure reducing cavity A is communicated with the valve sleeve hole, and the pressure reducing cavity C is communicated with the liquid outlet channel; the valve clack is of a double-sealing-pair structure and a three-stage pressure reduction cavity structure, and a three-stage pressure reduction cavity has the functions of sound insulation, noise reduction and shock absorption. Erosive wear to a sealing surface is reduced, and the probability of external leakage is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of valves, and in particular relates to a high-pressure differential anti-scour and low-noise stop valve. Background Art

[0002] The globe valve is one of the earliest valve types developed and applied. Its operating principle is that an operating element (such as a handwheel, reducer, pneumatic actuator, or electric actuator) installed on the valve drives the valve stem up and down, causing the closing element (valve disc) to vertically disengage or press against the valve seat, thereby conducting or shutting off the fluid medium. Globe valves are commonly used for boiler blowdown. Installed on the water-cooled wall piping of supercritical and ultra-supercritical boilers, they remove insoluble impurities such as slag, sludge, and soft sediment deposited at the bottom of the boiler to prevent scaling and corrosion.

[0003] Existing globe valves used for regular boiler blowdown present several challenges. Because the boiler's regular blowdown contains solid particles and is of poor quality, the heat removed by the blowdown is minimal, representing only 0.1-0.5% of the evaporation rate. This heat is typically not (or is not easily) recovered, and is discharged directly into the air. Consequently, the discharge pressure differential is large, severely impacting the valve sealing surfaces. Especially during the moment of valve opening, when the disc is slightly open, the high-velocity medium creates an extremely high pressure differential, which erodes the primary sealing element (i.e., the valve seat and disc sealing surfaces). This erosion is similar to high-pressure fluid shearing, rapidly damaging the closure. When the valve is opened for blowdown, the high flow rate produces an extremely piercing noise, severely impacting the on-site and surrounding work environment. Typically, existing globe valves used for blowdown rarely last more than three months. In extreme cases, they can leak severely within a week, losing their sealing function and causing significant heat loss. Steam impacts the valve cover, causing the stem and cover sealing surfaces to fail, leading to leakage, reduced thermal efficiency, and environmental pollution. Therefore, it is imperative to design a globe valve that resists high pressure differential erosion and reduces noise to replace conventional globe valves for boiler blowdown. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a high-pressure differential, erosion-resistant, low-noise stop valve, which effectively solves the problems of high pressure difference, large erosion, high peak noise and easy leakage when the stop valve is used for boiler sewage discharge.

[0005] To achieve the above-mentioned objectives, the technical scheme adopted by the present invention is as follows: a high-pressure differential anti-scour and low-noise stop valve, comprising a valve body, a valve cover, a valve seat, a valve stem, and a valve disc, the valve body having a valve cavity, the valve body being respectively provided with a liquid inlet channel and a liquid outlet channel connected to the valve cavity, the valve seat being arranged in the valve cavity, the valve seat being provided with a valve seat hole connected to the liquid inlet channel, the valve seat being provided with a valve sleeve, the valve sleeve being provided with a valve sleeve hole connected to the valve seat hole, the valve disc being linked and arranged on the valve stem and sealingly matched with the valve sleeve, one end of the valve disc having a conical sealing portion sealingly matched with the valve seat hole, a convex ring sealing portion sealingly matched with the valve sleeve being provided between the corresponding conical sealing portion on the valve disc and the valve sleeve hole, the valve cavity having A decompression chamber, B decompression chamber, and C decompression chamber connected in sequence, the A decompression chamber being connected with the valve sleeve hole, and the C decompression chamber being connected with the liquid outlet channel.

[0006] In some embodiments, the diameter of the conical sealing portion is smaller than the diameter of the convex ring sealing portion, and an arcuate groove is provided on the valve disc corresponding to the conical sealing portion and the convex ring sealing portion.

[0007] In some embodiments, a baffle is provided in the valve cavity to separate the A decompression chamber and the B decompression chamber, and a through hole is provided on the baffle to connect the A decompression chamber and the B decompression chamber.

[0008] In some embodiments, a cage is provided in the valve cavity to separate the B decompression chamber and the C decompression chamber, and a plurality of cage holes are provided on the cage to connect the B decompression chamber and the C decompression chamber.

[0009] In some embodiments, guide slopes are provided on both sides of the convex ring sealing portion.

[0010] In some embodiments, the valve sleeve has a guide hole for the valve disc to pass through, and the valve disc is provided with a plurality of sealing rings along its axial direction for sealingly cooperating with the valve sleeve.

[0011] In some embodiments, a reverse seal is provided between the valve stem and the valve cover, and a sealing step is provided on the valve stem to cooperate with the reverse seal. When the valve stem moves to the fully open position, the valve stem drives the sealing step to contact the reverse seal.

[0012] In some embodiments, a layer of STL hard alloy is welded on the conical surface sealing portion, the convex ring sealing portion, and the valve seat hole.

[0013] In some embodiments, the valve body is provided with a flange for pressing the valve cover onto the valve body, and a sealing ring is provided between the valve body, the valve cover and the flange.

[0014] In some embodiments, a buffer mechanism is further included in the liquid inlet channel, wherein the buffer mechanism includes an orifice plate and an elastic member. The orifice plate is slidably arranged in the liquid inlet channel and is used to buffer the impact force of the liquid in the liquid inlet channel. The elastic member is arranged between the orifice plate and the valve seat. The elastic force of the elastic member enables the orifice plate to block the impact force of the liquid. The orifice plate is respectively provided with a plurality of through holes for liquid circulation.

[0015] The present invention has the following beneficial effects: The valve disc utilizes a dual-seal structure and a three-stage pressure-reducing chamber design. The first-stage seal pair utilizes a conical seal structure, and the second-stage seal pair utilizes a convex ring seal structure. When the valve is open, the high-velocity medium generated by a small opening is flushed from the first-stage seal pair to the second-stage seal pair, effectively reducing the pressure drop across the first-stage seal pair at the moment the valve opens, thereby reducing the erosion of the first-stage seal pair by the high-pressure differential. The three-stage pressure-reducing chamber provides sound insulation, noise reduction, and vibration reduction. It also gradually reduces the pressure drop across the medium flowing through the valve during the valve opening and drainage period, effectively protecting the sealing surfaces of the second-stage seal pair, the valve stem, and the flap, minimizing erosion and wear on the sealing surfaces, reducing the likelihood of external leakage, and significantly extending the service life of the stop valve during drainage. Furthermore, it reduces noise and improves the working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0017] Figure 1 This is a structural diagram of an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of part A in the middle; Figure 3 This is a schematic structural diagram of an embodiment of the present invention when the valve flap opening height is h; Figure 4 This is a schematic diagram of the structure of the valve flap after it is fully opened according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having" and any variations thereof in the present specification and claims and the accompanying drawings are intended to cover non-exclusive inclusions.

[0020] The terms used herein, such as "up," "down," "front," "back," "left," "right," "inside," "outside," "top," "bottom," and "side," are intended solely to refer to the accompanying drawings. These terms are intended to illustrate and facilitate understanding of the present invention and are not intended to limit its scope.

[0021] The present invention will now be further described with reference to the accompanying drawings and specific embodiments: like Figure 1-3As shown, a high-pressure differential anti-scour and low-noise stop valve includes a valve body 1, a valve cover 2, a valve seat 3, a valve stem 4, and a valve disc 5. The valve body 1 has a valve cavity 100. The valve body 1 is respectively provided with a liquid inlet channel 101 and a liquid outlet channel 102 connected to the valve cavity 100. The valve seat 3 is arranged in the valve cavity 100. The valve seat 3 is provided with a valve seat hole 31 connected to the liquid inlet channel 101. The valve seat 3 is provided with a valve sleeve 6. The valve sleeve 6 is provided with a valve sleeve hole 61 connected to the valve seat hole 31. The valve disc 5 is linked to the valve stem 4 and seals with the valve sleeve 6. One end of the valve disc 5 has a conical sealing portion 51 that seals with the valve seat hole 31. A convex ring sealing portion 52 that seals with the valve sleeve 6 is provided between the corresponding conical sealing portion 51 and the valve sleeve hole 61 on the valve disc 5. The valve cavity 100 has a pressure reducing chamber A 103, a pressure reducing chamber B 104, and a pressure reducing chamber C 105 that are connected in sequence. Pressure-reducing chamber A 103 communicates with the valve sleeve hole 61, and pressure-reducing chamber C 105 communicates with the liquid outlet channel 102. The diameter of the conical sealing portion 51 is smaller than that of the convex ring sealing portion 52, and the valve disc 5 includes an arcuate groove 53 between the corresponding conical sealing portion 51 and the convex ring sealing portion 52. The arcuate groove guides the flow of the medium, preventing impurities from accumulating at the sealing surface interface, and reducing the risk of clogging or scratching the sealing surface. When the valve is opened and closed, the medium flowing through the groove generates local eddy currents, which self-clean the sealing surface interface. This helps extend the sealing life of the stop valve. A baffle 7 is provided within the valve chamber 100, separating pressure-reducing chamber A 103 from pressure-reducing chamber B 104. The baffle 7 is provided with a through hole 71 connecting pressure-reducing chamber A 103 and pressure-reducing chamber B 104. The through hole in the baffle acts as a throttling mechanism to reduce flow rate and pressure, preventing high-speed erosion of the sealing surface, thereby extending the sealing life of the stop valve. A cage 8 is located within the valve chamber 100, separating the pressure-reducing chambers B 104 and C 105. Cage 8 is provided with multiple cage holes 81, connecting the pressure-reducing chambers B 104 and C 105. The cage, with its multiple regularly arranged cage holes, divides the medium into multiple streams as it passes through the cage holes. This progressive throttling reduces the flow rate and pressure, preventing cavitation, flashing, or high-velocity erosion under high pressure differentials. This helps extend the seal life of the globe valve.

[0022] like Figure 2-4As shown, guide bevels 521 are provided on either side of the convex ring sealing portion 52. These bevels guide the valve disc 5 more precisely against the sealing surface during closing, preventing poor sealing or localized wear caused by misalignment. This ensures compliance with high differential pressure or frequent operation requirements. The valve sleeve 6 has a guide hole 62 for the valve disc 5 to pass through. Multiple sealing rings 54 are provided along the axial direction of the valve disc 5, which seal with the valve sleeve 6. These multiple sealing rings create an axial seal between the valve disc and the sleeve, thereby improving the sealing performance between the valve disc and the sleeve. A reverse seal 21 is provided between the valve stem 4 and the valve cover 2. The valve stem 4 is equipped with a sealing step 41 that mates with the reverse seal 21. When the valve stem 4 moves to the fully open position, the valve stem 4 drives the sealing step 41 into contact with the reverse seal 21. When the valve is fully open, the valve stem is pressed against the reverse seal via the sealing step, effectively improving the sealing performance between the valve stem and the valve cover and preventing leakage. A layer of STL hard alloy is welded onto the conical seal 51, the convex ring seal 52, and the interior of the valve seat hole 31. The STL welded structure design on the conical seal, the convex ring seal, and the interior of the valve seat hole effectively improves the wear resistance, corrosion resistance, high-temperature stability, and sealing performance of the sealing surfaces of these parts, effectively resisting media erosion and particle wear, and extending the life of the valve sealing surfaces.

[0023] like Figure 1 and 2 As shown, the valve body 1 is provided with a flange 11 for pressing the valve cover 2 onto the valve body 1, and a sealing ring 12 is provided between the valve body 1, the valve cover 2 and the flange 11. The sealing ring is pressed between the valve body and the valve cover by the flange, which is beneficial to improving the sealing performance of the valve body and the valve cover. It also includes a buffer mechanism 9 arranged in the liquid inlet channel 101, and the buffer mechanism 9 includes an orifice plate 91 and an elastic member 92. The orifice plate 91 is slidably arranged in the liquid inlet channel 101 and is used to buffer the impact force of the liquid in the liquid inlet channel. The elastic member 92 is arranged between the orifice plate 91 and the valve seat 3. The elastic force of the elastic member 92 enables the orifice plate 91 to block the impact force of the liquid. The orifice plate 91 is respectively provided with a plurality of through holes 911 for liquid circulation. The buffer mechanism adopts an elastic structure design, and the orifice plate can effectively reduce the impact force of the liquid in the liquid inlet channel, which is beneficial to extending the sealing life of the valve. The orifice plate 91 slides within a sliding guide groove provided within the liquid inlet channel 101. The elastic member 92 is a spring, one end of which abuts against the positioning groove of the orifice plate 91 and the other end against the valve seat 3. The orifice plate's sliding guide groove within the liquid inlet channel ensures reliable operation within the groove. The buffer mechanism utilizes a spring-like design, providing a buffering effect that effectively reduces the impact of high-velocity media, thereby extending the valve's seal life.

[0024] The disc utilizes a dual-seal structure and a three-stage pressure-reducing chamber design. The first-stage seal utilizes a conical seal, while the second-stage seal utilizes a convex ring seal. When the valve is open, the high-velocity flow generated by a small opening is transferred from the first-stage seal to the second-stage seal, effectively reducing the pressure drop across the first-stage seal at the moment the valve opens, thereby minimizing erosion caused by the high-pressure differential. The three-stage pressure-reducing chamber provides sound insulation, noise reduction, and vibration reduction. It also progressively reduces the pressure drop across the valve during the blowdown period, effectively protecting the sealing surfaces of the second-stage seal, stem, and flap, minimizing erosion and wear on these surfaces and reducing the likelihood of leakage. This significantly extends the service life of the globe valve during blowdown, while also reducing noise and improving the working environment.

[0025] When the main sealing pair of the valve is closed to achieve sealing, the sealing height of the second sealing pair is h (such as Figure 2 ). When the valve is opened (as shown in Figure 3), the valve stem drives the valve disc upward. When the opening height reaches h, sealing pair II is at the critical opening and closing position, and sealing pair I has formed an annular channel with a width of δ. The valve continues to open to a smaller opening (>h). At sealing pair II, the convex ring sealing portion of the valve disc separates from the valve sleeve hole. As the opening increases, the increase in the channel area at sealing pair I is much greater than the increase in the channel area at sealing pair II. In other words, the medium flow rate V2 at sealing pair II is much greater than the medium flow rate V1 at sealing pair I. According to Bernoulli's equation, the medium pressure drop △P=ρV 2 / 2. From this, we can see that the pressure drop between sealing pairs II and I is ΔPII > ΔPI. Therefore, at small openings, the location most severely impacted by the medium shifts from sealing pair I to sealing pair II, significantly reducing the erosion of the high pressure differential between the valve seat and disc sealing surface and extending the valve seal lifecycle.

[0026] When the valve is fully opened (as shown in Figure 4), the stem sealing step presses against the inverted seal, allowing the inverted seal to function. The medium flows through the valve seat and sleeve holes, sequentially flowing to pressure relief chambers A, B, and C (pressures in pressure relief chamber A are ΔPa, pressures in pressure relief chamber B are ΔPb, and pressures in pressure relief chamber C are ΔPc), finally converging and exiting through the valve body outlet. The valve operating pressure is P, reaching a maximum of Pmax = 32 MPa. The valve outlet pressure is Po. During wastewater discharge, Po is generally close to atmospheric pressure. The pressure drop across the valve, ΔP, decreases in sequence to ΔPa, ΔPb, and ΔPc: ΔP = P - Po = ΔPa + ΔPb + ΔPc. Consequently, the pressure drop across the valve seat and disc seal is reduced from ΔP to ΔPa, thereby minimizing erosion and wear on the disc and seat sealing surfaces. When the valve is opened slightly, the high-velocity medium is soundproofed through the B cavity and the noise is reduced by the C cavity covering the side, which greatly reduces the noise generated by the medium flowing through the valve and reduces the vibration during valve operation.

[0027] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention; the scope of protection of the present invention is defined by the claims in the appended claims, and all equivalent changes and modifications made based on the invention are within the scope of protection of the patent of the present invention.

Claims

1. A high-pressure differential anti-scour low-noise stop valve, comprising a valve body, a valve cover, a valve seat, a valve stem, and a valve disc, characterized in that: The valve body has a valve cavity, and the valve body is respectively provided with a liquid inlet channel and a liquid outlet channel connected with the valve cavity. The valve seat is arranged in the valve cavity, and the valve seat is provided with a valve seat hole connected with the liquid inlet channel. The valve seat is provided with a valve sleeve, and the valve sleeve is provided with a valve sleeve hole connected with the valve seat hole. The valve disc is linked and arranged on the valve stem and sealed with the valve sleeve. One end of the valve disc has a conical sealing portion that is sealed with the valve seat hole. A convex ring sealing portion that is sealed with the valve sleeve is provided between the corresponding conical sealing portion on the valve disc and the valve sleeve hole. The valve cavity has A decompression chamber, B decompression chamber, and C decompression chamber that are connected in sequence. The A decompression chamber is connected with the valve sleeve hole, and the C decompression chamber is connected with the liquid outlet channel.

2. The high-pressure differential anti-scour low-noise stop valve according to claim 1, characterized in that: The diameter of the conical surface sealing portion is smaller than the diameter of the convex ring sealing portion, and an arc surface groove is provided on the valve disc corresponding to the conical surface sealing portion and the convex ring sealing portion.

3. The high-pressure differential anti-scour low-noise stop valve according to claim 1 or 2, characterized in that: A baffle is provided in the valve cavity to separate the A decompression cavity and the B decompression cavity, and a through hole is provided on the baffle to connect the A decompression cavity and the B decompression cavity.

4. The high-pressure differential anti-scour low-noise stop valve according to claim 1 or 2, characterized in that: A valve cage is provided in the valve cavity to separate the B pressure relief chamber and the C pressure relief chamber. A plurality of valve cage holes for connecting the B pressure relief chamber and the C pressure relief chamber are respectively provided on the valve cage.

5. The high-pressure differential anti-scour low-noise stop valve according to claim 1 or 2, characterized in that: Guide slopes are respectively provided on both sides of the convex ring sealing portion.

6. The high-pressure differential anti-scour low-noise stop valve according to claim 1, characterized in that: The valve sleeve has a guide hole for the valve disc to pass through, and the valve disc is provided with a plurality of sealing rings along its axial direction for sealingly cooperating with the valve sleeve.

7. The high-pressure differential anti-scour low-noise stop valve according to claim 1, characterized in that: A reverse seal is provided between the valve stem and the valve cover, and a sealing step cooperating with the reverse seal is provided on the valve stem. When the valve stem moves to the fully open position, the valve stem drives the sealing step to contact the reverse seal.

8. The high-pressure differential anti-scour and low-noise stop valve according to claim 1, characterized in that: A layer of STL hard alloy is welded on the conical surface sealing portion, the convex ring sealing portion and the valve seat hole.

9. The high-pressure differential anti-scour low-noise stop valve according to claim 1, characterized in that: The valve body is provided with a flange for pressing the valve cover onto the valve body, and a sealing ring is provided between the valve body, the valve cover and the flange.

10. The high-pressure differential anti-scour low-noise stop valve according to claim 1, characterized in that: It also includes a buffer mechanism arranged in the liquid inlet channel, the buffer mechanism includes an orifice plate and an elastic member, the orifice plate is slidably arranged in the liquid inlet channel and is used to buffer the impact force of the liquid in the liquid inlet channel, the elastic member is arranged between the orifice plate and the valve seat, the elastic force of the elastic member enables the orifice plate to block the impact force of the liquid, and the orifice plate is respectively provided with a plurality of through holes for liquid circulation.

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