An internally self-sealing dynamic compensation gate valve

Abstract

This invention relates to the field of fluid control valve technology. The invention discloses an internally self-tightening sealing dynamic compensation gate valve, comprising a valve body and a valve cover. The valve body has a through-flow channel, and a valve cavity is located in the middle of the flow channel. A gate assembly is disposed within the valve cavity. The valve ...

Description

Technical Field

[0001] This invention relates to the field of fluid control valve technology, and more specifically, to an internally self-tightening sealing dynamic compensation gate valve. Background Technology

[0002] Gate valves are the most widely used shut-off devices in pipeline systems of industries such as petroleum, chemical, and power. Their core function is to cut off the flow of media by tightly fitting the gate and the valve seat. Under high temperature and high pressure conditions (such as hydrocracking units and supercritical thermal power units), in order to improve sealing reliability, the industry often adopts internal self-tightening or pressure sealing structures, that is, using the pressure of the medium itself to press the valve seat against the gate, or using the wedge-shaped gate's wedge-tightening effect to achieve sealing.

[0003] Although existing mechanical gate valve technology is relatively mature, inherent mechanical structural defects still lead to the following insurmountable technical bottlenecks when dealing with extreme operating conditions and long-term operation: 1. The limitations of passive compensation capabilities lead to low-pressure leakage and wear failure. Existing self-tightening gate valves typically have a disc spring or cylindrical helical spring behind the valve seat to provide initial preload and compensate for wear on the sealing surface. However, this compensation method relying on elastic metal elements is entirely passive.

[0004] First, the spring's output force changes linearly with displacement and cannot be adjusted in real time according to fluctuations in medium pressure. When the system is under low pressure, the medium thrust is insufficient, and the spring preload is fixed, which can easily lead to a sealing pressure lower than the required pressure, resulting in micro-leakage.

[0005] Secondly, as the valve is opened and closed for a long time, the sealing surface wears down, causing the gap to increase. The spring stretches and its elasticity decreases, which in turn reduces the sealing performance and makes it impossible to maintain a constant sealing efficiency.

[0006] 2. Constant stiffness cannot simultaneously guarantee sealing performance and flexibility. The stiffness of the valve seat support structure is a design contradiction.

[0007] To resist the enormous back thrust of the high-pressure medium and prevent leakage caused by valve seat retraction, the support structure behind the valve seat needs to have extremely high rigidity.

[0008] However, in order to accommodate gate machining errors, thermal deformation, and achieve automatic centering, the valve seat support structure also needs to have a certain degree of flexibility.

[0009] Existing mechanical support structures (whether rigid or spring-loaded) have fixed stiffness characteristics and cannot be switched according to the valve's operating stage (e.g., softening when floating centering is required and hardening when high pressure cutoff is required). This often results in one aspect being neglected while the other is achieved, leading to valve seat retraction under high pressure or abrasion of the sealing surface during opening and closing.

[0010] 3. Operational Challenges Caused by Thermal Seizure: This is a common problem for gate valves operating at high temperatures. When the valve closes at high temperatures, as the system cools down, the shrinkage of the valve body material is often greater than that of the gate (or due to differences in cooling rates), causing the valve seat to be squeezed inward, forming an interference fit with the wedge-shaped gate, i.e., thermal seizure. In existing mechanical structures, the spring behind the valve seat mainly provides unidirectional preload, making it difficult to achieve active retraction or unloading. This results in significant contact stress between the gate and the valve seat when the valve reopens, often requiring an opening torque far exceeding the normal value. In severe cases, this can lead to abrasion of the sealing surface or damage to the valve stem, affecting the emergency start-up and shutdown response of the device. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention discloses an internally self-tightening sealing dynamic compensation gate valve to solve the problem of thermal seizure under high-temperature conditions. It includes a valve body and a valve cover. The valve body has a through-flow channel, with a valve cavity located in the middle of the channel. A gate assembly is disposed within the valve cavity. It also includes a pair of self-compensating valve seat assemblies disposed within the valve cavity. Each self-compensating valve seat assembly includes a support ring seat and a floating sealing ring. The inner wall of the valve cavity has stepped holes for fixing the support ring seats. The support ring seat has an annular receiving chamber for mounting the floating sealing ring. Magnetorheological fluid fills the annular receiving chamber. A super-magnetostrictive drive element is located within the annular receiving chamber and abuts against the bottom of the floating sealing ring and the annular receiving chamber.

[0012] Furthermore, one end of the floating sealing ring is slidably inserted into the annular receiving chamber in a piston shape, and the other end of the floating sealing ring is provided with a hard alloy sealing layer for mating with the sealing surface of the gate assembly.

[0013] Furthermore, an excitation coil is pre-embedded in the support ring seat, and the excitation coil is arranged around the annular receiving chamber to apply an adjustable magnetic field to the magnetorheological fluid.

[0014] Furthermore, multiple magnetostrictive drive elements are evenly distributed along the circumference within the annular receiving chamber. Each magnetostrictive drive element is surrounded by a drive coil to generate a drive magnetic field to control the axial elongation of the magnetostrictive drive element. A pre-tightening elastic element is connected in series at one end of the magnetostrictive drive element near the bottom of the annular receiving chamber. The pre-tightening elastic element is configured to ensure that the magnetostrictive drive element is always subjected to axial compressive stress.

[0015] Furthermore, a dynamic sealing ring is provided between the outer wall of the floating sealing ring and the inner wall of the annular receiving chamber; one end of the floating sealing ring inserted into the annular receiving chamber is truncated conical in shape, and the bottom of the annular receiving chamber is fitted with it in the shape of an inner conical hole, and magnetorheological fluid is filled between the conical surface of the floating sealing ring and the surface of the inner conical hole of the annular receiving chamber.

[0016] Furthermore, the cone angle of the truncated cone is between 15° and 25°.

[0017] Furthermore, it also includes: an intelligent control module and a pressure sensor. The pressure sensor is located at the outlet of the flow channel. The excitation coil, drive coil, and pressure sensor are all electrically connected to the intelligent control module. The intelligent control module is configured as follows: After receiving the first control signal, current is supplied to the drive coil, and the super magnetostrictive drive element generates an axial displacement thrust along the sealing direction. After receiving the second control signal, current is supplied to the excitation coil, and the magnetorheological fluid switches between a flexible floating state and a rigid locking state, providing variable axial support stiffness for the floating sealing ring.

[0018] Furthermore, the intelligent control module is configured to execute zero-energy-consumption interlocking sealing control according to a preset timing logic upon receiving the first control signal: The intelligent control module first outputs a zero current or a low-intensity bias current to the excitation coil to control the magnetorheological fluid to be in a low-viscosity, flexible floating state, so as to eliminate the viscous resistance to the movement of the floating sealing ring. The intelligent control module supplies a driving current to the driving coil, controls the super magnetostrictive driving element to generate axial elongation and pushes the floating sealing ring toward the gate assembly until a preset sealing pressure ratio is established between the floating sealing ring and the gate assembly. Keeping the driving current supplied to the driving coil constant, while simultaneously supplying a saturated excitation current to the excitation coil, the magnetorheological fluid is switched to a rigid locking state by utilizing the shear yielding effect of the magnetic field, and the floating sealing ring is axially fixed by the solidified magnetorheological fluid layer. The intelligent control module gradually reduces and cuts off the current flowing into the drive coil. It utilizes the self-locking effect formed by the magnetic rheological fluid, which is already in a rigid locked state, and the conical surface of the floating sealing ring to replace the super magnetostrictive drive element in maintaining the axial position and sealing pressure of the floating sealing ring, thereby eliminating the thermal decay effect of Joule heat generated by continuous energization on the performance of the super magnetostrictive drive element.

[0019] Furthermore, the intelligent control module is also configured to perform micro-vibration coordinated unlocking control when it receives a valve opening command and generates the second control signal: The intelligent control module first cuts off the current supplied to the excitation coil, so that the magnetorheological fluid returns from a rigid locked state to a liquid state, thereby releasing the rigid constraint between the floating sealing ring and the annular accommodating chamber. Subsequently, the intelligent control module supplies a composite current superimposed with a high-frequency AC component to the drive coil, driving the super magnetostrictive drive element to generate axial micro-amplitude high-frequency vibration. The axial micro-amplitude high-frequency vibration is used to break the static friction bonding layer formed between the floating sealing ring and the sealing surface of the gate assembly due to high temperature and high pressure, and the floating sealing ring is retracted into the annular receiving chamber under the restoring force of the pre-tightened elastic element.

[0020] Furthermore, the intelligent control module is also configured to execute an anti-settlement self-maintenance procedure when the valve is in a long-term static state: The intelligent control module periodically supplies short-time pulse current to the drive coil according to a preset maintenance cycle, driving the super magnetostrictive drive element to generate micro-movements in the annular accommodative chamber. The micro-motion of the super magnetostrictive drive element is used as a stirring source to agitate the magnetorheological fluid filled in the annular containment chamber, so as to prevent the magnetic particles from settling and caking under the action of gravity, and ensure that the magnetorheological fluid always maintains a uniform dispersion state and controllable rheological properties.

[0021] Compared with the prior art, the present invention has the following advantages: (1) The present invention provides an internally self-tightening sealing dynamic compensation gate valve, which effectively improves the opening performance under high-temperature thermal lock-up conditions. It provides an active unloading mechanism through the coordinated control of a super magnetostrictive drive element and a magnetorheological fluid. Before the valve opens, the control system reduces the drive current, the super magnetostrictive element retracts to cancel the thrust, and at the same time adjusts the excitation coil current to change the state of the magnetorheological fluid, reducing the support stiffness, so that the floating sealing ring can retract into the inner receiving chamber under the action of contact stress. This displacement cancellation combined with stiffness adjustment mechanism helps to reduce the opening torque of the gate valve under thermal lock-up conditions, protecting the sealing surface and the actuator.

[0022] (2) The present invention provides an internally self-tightening sealing dynamic compensation gate valve, which realizes dynamic adjustment of the sealing support stiffness. It utilizes the controllable rheological properties of magnetorheological fluid to optimize the support performance of the valve seat: under valve opening and closing or low-pressure conditions, the magnetorheological fluid is in a low viscosity state, allowing the floating sealing ring to generate a small amount of floating to adapt to the centering deviation of the gate; under high-pressure shut-off conditions, by applying a magnetic field, the shear yield stress of the magnetorheological fluid is increased, and the wedge-shaped extrusion effect formed by the truncated conical mating surface provides high rigidity support for the sealing ring, thereby improving the sealing reliability under high-pressure conditions. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an internally self-tightening sealing dynamic compensation gate valve disclosed in this invention; Figure 2 This is a cross-sectional view of the self-compensating valve seat assembly in an internally self-tightening sealing dynamic compensation gate valve disclosed in this invention. Figure 3 for Figure 2 Enlarged view of number A.

[0025] In the figure: 10. Valve body; 11. Valve cover; 12. Flow channel; 13. Valve cavity; 14. Gate assembly; 15. Self-compensating valve seat assembly; 16. Support ring seat; 17. Floating sealing ring; 18. Annular receiving chamber; 19. Magnetostrictive drive element; 20. Hard alloy sealing layer; 21. Excitation coil; 22. Magnetorheological fluid; 23. Drive coil; 24. Preload elastic element. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: As Figures 1 to 3 As shown, this embodiment discloses an internally self-tightening sealing dynamic compensation gate valve, mainly comprising a valve body 10 and a valve cover 11. The valve body 10 has a through flow channel 12, and the valve cavity 13 is located in the middle of the flow channel 12. A gate assembly 14, typically including a gate and a valve stem, is disposed within the valve cavity 13 and is used to cut off the medium.

[0028] A pair of self-compensating valve seat assemblies 15 are symmetrically arranged on both sides of the gate assembly 14 within the valve chamber 13. Each set of self-compensating valve seat assemblies 15 includes a support ring seat 16 and a floating sealing ring 17.

[0029] Fixed installation: The inner wall of the valve cavity 13 is provided with a stepped hole, and the support ring seat 16 is fixedly installed in the stepped hole by means of thread or interference fit.

[0030] Reception structure: The support ring seat 16 has a deep groove-shaped annular reception chamber 18 on the side facing the gate.

[0031] Active seal: One end of the floating sealing ring 17 is slidably inserted into the annular receiving chamber 18 in a piston shape. To prevent media leakage, a dynamic sealing ring 25 is provided between the outer wall of the floating sealing ring 17 and the inner wall of the annular receiving chamber 18. The protruding end of the floating sealing ring 17 is provided with a hard alloy sealing layer 20 for cooperating with the gate assembly 14.

[0032] The core improvement in this embodiment is that the end of the floating sealing ring 17 inserted into the annular receiving chamber 18 is designed as a truncated cone. Correspondingly, the bottom of the annular receiving chamber 18, specifically the outer ring area, is designed as an inner conical hole to mate with it. The conical surface of the floating sealing ring 17 and the surface of the inner conical hole of the annular receiving chamber 18 are not completely fitted together, but rather a certain gap is formed, which is filled with magnetorheological fluid 22. An excitation coil 21 is pre-embedded in the support ring seat 16. This coil is arranged around the annular receiving chamber 18 to change the rheological properties of the magnetorheological fluid 22.

[0033] Drive and Assembly Details: The super-magnetostrictive drive element 19 (in this embodiment, multiple circumferentially distributed super-magnetostrictive rods) is located inside the annular receiving chamber 18 and immersed in the magnetorheological fluid 22. Each element is surrounded by a drive coil 23. One end of the super-magnetostrictive drive element 19 abuts against the rear end face of the floating sealing ring 17, which is typically a flat surface inside a cone, while the other end abuts against the bottom of the annular receiving chamber 18 via a pre-tensioned elastic element 24. The pre-tensioned elastic element 24, such as a disc spring, is connected in series at the tail of the element to ensure that the element always bears axial compressive stress.

[0034] Alternatively, the super magnetostrictive drive element 19 can also be tubular or stacked, as long as it is located in the containment chamber and can generate magnetostrictive displacement.

[0035] Example 2: The difference between this example and Example 1 is that the geometry of the mating surfaces is simplified. In this example, the end of the floating sealing ring 17 inserted into the annular receiving chamber 18 has a standard cylindrical piston structure, and correspondingly, the annular receiving chamber 18 is also a straight cylindrical deep groove. Magnetorheological fluid 22 fills the cavity between the rear end face of the floating sealing ring 17 and the bottom of the annular receiving chamber 18, as well as the gap on the side of the piston. The supermagnetic-strictive drive element 19 is also disposed in this cavity, directly generating axial thrust.

[0036] Technical effect comparison: Although the cylindrical mating surface of this embodiment is slightly inferior to the conical structure of Embodiment 1 in terms of the pressing film effect and anti-backward support force, it is easier to process and assemble. By using the excitation coil 21 to solidify the magnetorheological fluid 22 in the gap of the cylindrical surface, the switching between flexible floating and rigid locking can also be achieved by utilizing the shear thickening effect.

[0037] Example 3: Based on Example 1, this example discloses that the cone angle of the truncated cone is between 15° and 25°, and provides a detailed description of the key parameters and structure.

[0038] Regarding the limitation of the cone angle, the cone angle of the truncated cone of the floating sealing ring 17 is strictly limited to between 15° and 25°.

[0039] Technical principle: When the cone angle is less than 15°, although the force-increasing effect is obvious, mechanical self-locking is likely to occur, which will cause the floating sealing ring 17 to fail to retract quickly after power failure, affecting the anti-locking effect; when the cone angle is greater than 25°, the fluid wedge compression effect of the magnetorheological fluid 22 under pressure will decrease significantly, and the support stiffness will be insufficient.

[0040] Preferred values: In this embodiment, a cone angle of 20° is preferably used, combined with a liquid film gap of 0.8mm, which ensures both high pressure support and rapid response at the moment of power failure.

[0041] Regarding the installation of the pre-tensioning elastic element, this embodiment clarifies that the pre-tensioning elastic element 24, a high-temperature resistant disc spring, is installed at the rear end of the super magnetostrictive drive element 19, i.e., on the side near the bottom of the annular receiving chamber 18.

[0042] Optimization effect: This layout allows the front end of the magnetostrictive rod to directly push the floating sealing ring 17, avoiding the lateral force that might cause the rod to break due to the front-mounted spring. At the same time, when the anti-lock unlocking is performed and the floating sealing ring 17 retracts rapidly, the pre-tightened elastic element 24 located at the rear end can effectively absorb the impact energy, protecting the brittle magnetostrictive drive element 19 from being broken.

[0043] Example 4: Based on Example 1, this example further includes: an intelligent control module and a pressure sensor. The pressure sensor is located at the outlet of the flow channel 12. The excitation coil 21, the drive coil 23, and the pressure sensor are all electrically connected to the intelligent control module. The intelligent control module is configured as follows: After receiving the first control signal, current is supplied to the drive coil 23, and the super magnetostrictive drive element 19 generates an axial displacement thrust along the sealing direction. After receiving the second control signal, current is supplied to the excitation coil 21, and the magnetorheological fluid 22 switches between a flexible floating state and a rigid locking state, providing variable axial support stiffness for the floating sealing ring 17.

[0044] Example 5: In extreme industrial applications such as petrochemicals, valves often need to remain closed for weeks, months, or even years to cut off high-pressure fluids. It is well known that rare-earth magnetostrictive materials such as Terfenol-D, while possessing high output force, are extremely sensitive to temperature changes. Under conventional control logic, to maintain a sealing pressure capable of withstanding medium pressure, a high-intensity drive current must be continuously supplied to the drive coil 23. However, according to Joule's law, a continuous high current inevitably leads to coil heating, which is rapidly conducted to the encased magnetostrictive drive element 19. Physical properties indicate that as the substrate temperature rises, the thermal disturbance of the magnetic domains within the magnetostrictive material intensifies, causing its magnetostriction coefficient to exhibit a non-linear and rapid decay. This thermal decay effect leads to the following in engineering: to compensate for the thrust reduction caused by thermal decay, the controller is forced to increase the drive current. This increased current generates more heat, further reducing material performance, ultimately leading to the inability to maintain the sealing pressure and resulting in medium leakage, or even burnout of the coil insulation layer due to overheating.

[0045] Therefore, the specific control flow of the intelligent control module in this embodiment is as follows: When the intelligent control module triggers the sealing action by receiving a first control signal (such as a remote shutdown command) or detecting an abnormal pressure in the flow channel 12 fed back by the pressure sensor, it does not immediately start the drive. The intelligent control module first performs an initial scan and regulation of the current state of the excitation coil 21 in the support ring seat 16. If residual current is detected in the excitation coil 21, the intelligent control module controls the excitation drive circuit to quickly adjust the excitation current to zero or output a very low intensity bias current (e.g., 10mA to 50mA, which is only used to maintain the anisotropy of the magnetic circuit but does not generate an effective magnetic field). In this state, the thin layer of magnetorheological fluid 22 filled in the annular receiving chamber 18, especially located between the outer wall of the truncated cone of the floating sealing ring 17 and the conical hole in the annular receiving chamber 18, rapidly undergoes a reverse rheological response. The micron-sized soft magnetic particles inside it recover their disordered distribution under the action of Brownian motion, and macroscopically the medium switches from a near-solid state to a low-viscosity Newtonian fluid state or a quasi-Newtonian fluid state, that is, it enters a flexible floating state. Understandably, the physical significance of this step is to eliminate the viscous shear resistance that the floating sealing ring 17 may experience during axial movement to the greatest extent possible, ensuring that the valuable mechanical work output by the subsequent super magnetostrictive drive element 19 is mainly used to overcome the medium pressure and sealing contact stress, rather than being consumed in the viscous dissipation of the fluid, thereby significantly improving the drive efficiency.

[0046] After confirming that the magnetorheological fluid 22 is in a low-viscosity, flexible floating state (the system typically allows for a fluid relaxation time of 50ms to 100ms), the intelligent control module begins to supply driving current to the drive coil 23. To prevent damage to brittle materials caused by the impact vibration from the step current, the intelligent control module controls the driving current to increase according to a preset linear slope or S-curve. As the current establishes an axial driving magnetic field in the drive coil 23, multiple circumferentially distributed supermagnetostrictive drive elements 19 simultaneously undergo axial elongation deformation along the sealing direction. Since the floating sealing ring 17 is no longer rigidly bound by the magnetorheological fluid, the supermagnetostrictive drive elements 19 can efficiently push the floating sealing ring 17 forward, overcoming the resistance of the pre-tightened elastic element 24 and the friction of the dynamic sealing ring 25. The hard alloy sealing layer 20 at the front end of the floating sealing ring 17 gradually presses against the sealing surface of the gate assembly 14. During this process, the intelligent control module collects real-time feedback data from the pressure sensor located at the outlet of the flow channel 12 and calculates the current thrust output based on the driving current value. When the detected pressure value reaches the preset sealing pressure standard (e.g., 35 MPa), or the drive current reaches the preset saturation threshold, it is determined that the sealing pressure has been established. At this time, the intelligent control module locks the current drive current value, so that the magnetostrictive drive element 19 maintains the current elongation and thrust output, and the valve is in the transition state of electromagnetically maintained sealing.

[0047] This is the key physical process for achieving zero-energy maintenance. While maintaining a constant current in the drive coil 23, i.e., ensuring the floating sealing ring 17 does not retract, the intelligent control module rapidly activates the excitation circuit, supplying a high-intensity saturation excitation current (e.g., 2A to 5A) to the excitation coil 21 embedded in the support ring seat 16. The strong magnetic field generated by the excitation coil 21 passes perpendicularly through the gap between the annular receiving chamber 18 and the floating sealing ring 17. Within a millisecond-level time response range (typically less than 10ms), the magnetorheological fluid 22 within the gap undergoes a violent magnetorheological effect: magnetic particles suspended in the base fluid instantaneously aggregate along the magnetic field lines into coarse columnar chains or mesh structures, and the fluid state instantly transforms from liquid to a solid-like state (Bingham plastic) with extremely high shear yield stress (up to 50kPa to 100kPa). At this point, the solidified magnetorheological fluid 22 acts as a highly rigid hydraulic solid wedge, tightly filling the space between the floating sealing ring 17 and the annular receiving chamber 18. Because the present invention specifically designs a cone angle fit of 15 to 25 degrees, this geometric configuration, when combined with the solidified fluid, forms a significant pressing film effect and mechanical wedging effect. This dual self-locking of geometry and material greatly enhances the axial support stiffness, which is sufficient to withstand the huge reverse medium thrust.

[0048] Once the intelligent control module confirms that the magnetorheological fluid 22 has completely solidified and locked in place by detecting changes in the coil inductance, it begins executing the current unloading logic. The system gradually reduces and ultimately cuts off the current flowing into the drive coil 23 according to a preset descent slope. Theoretically, as the driving magnetic field disappears, the supermagnetostrictive drive element 19 will attempt to retract to release its elastic potential energy due to the disappearance of the magnetostrictive effect. However, because the floating sealing ring 17 is firmly held in place by the solid wedge formed by the solidified magnetorheological fluid 22, and this wedge structure has volumetric incompressibility, the floating sealing ring 17 cannot produce backward displacement. Ultimately, with the drive coil 23 completely de-energized, the axial position and sealing specific pressure of the floating sealing ring 17 are entirely maintained by the solid shear resistance of the magnetorheological fluid 22 and the mechanical self-locking force of the conical surface. At this time, the drive coil 23 is in a completely de-energized cooling state, completely cutting off the heat source and eliminating the risk of performance degradation of the supermagnetostrictive material due to temperature rise from the root. The excitation coil 21 only needs to maintain a static magnetic field (or even be completely de-energized if a permanent magnet bias scheme is adopted), thus achieving zero-energy high-pressure sealing at the system level.

[0049] For example: Scenario 1: In a 500℃ high-temperature pipeline of a hydrocracking unit, a valve needs to perform emergency shut-off and maintain pressure for an extended period. After receiving the command, the intelligent control module first removes the excitation magnetic field to liquefy the magnetorheological fluid; then it outputs a 12A drive current, causing the supermagnetostrictive drive element 19 to extend by approximately 80 micrometers, and the pressure sensor reports a sealing pressure of 30MPa; immediately afterward, it outputs a 3A excitation current, causing the magnetorheological fluid to solidify and lock within 5ms; finally, it reduces the 12A drive current to 0A within 1 second. Judgment result: After continuous monitoring, the valve sealing specific pressure stabilizes above 29.8MPa (with slight rebound within the allowable design range), and the drive coil temperature no longer rises, successfully achieving safe zero-energy pressure maintenance.

[0050] Example 6: In actual operating conditions, when the valve is closed at high temperature, as the system cools down, the shrinkage of the metal material of the valve body 10 is often greater than that of the internal gate assembly 14, resulting in a huge mechanical pressure (thermal seizure) on the gate from the valve seat. Furthermore, under prolonged high-temperature contact, microscopic atomic diffusion easily occurs between the hard alloy sealing layer 20 and the gate sealing surface, forming a high-strength adhesive layer, or adhesion occurs due to media coking. These factors significantly increase the static friction coefficient between the sealing surfaces, making it difficult for conventional spring return mechanisms to overcome this huge static friction force; forced opening may even lead to overload and damage to the actuator.

[0051] Therefore, the intelligent control module in this embodiment is configured not to directly perform a mechanical reset when it receives a valve opening command and generates a second control signal, but to strictly execute a dynamic-to-static unlocking procedure according to the following timing sequence: Upon receiving the activation command, the intelligent control module first cuts off the sustaining current supplied to the excitation coil 21, and then, as needed, supplies a short-duration reverse-damping demagnetizing pulse to the excitation coil 21 to completely eliminate residual magnetism in the magnetic circuit. With the disappearance of the magnetic field, the magnetic particle chains in the magnetorheological fluid 22 within the annular chamber 18 instantly collapse, and the fluid returns from a rigidly locked state to a low-viscosity liquid state. This step releases the axial rigid constraint and radial support of the floating sealing ring 17, restoring it from a dead-point state to a floating state, creating the necessary degrees of freedom for subsequent micro-motion.

[0052] After confirming the liquefaction of the magnetorheological fluid 22, the intelligent control module generates a special composite drive signal through its internal waveform generator. This signal is composed of a small DC bias component (e.g., 20% of the rated current) and a high-frequency AC component (e.g., a sine wave with a frequency of 500Hz to 2000Hz). The intelligent control module passes this composite current into the drive coil 23. Utilizing the excellent high-frequency response characteristics (response time on the order of microseconds) of the giant magnetostrictive material, the giant magnetostrictive drive element 19, driven by the composite current, does not produce large macroscopic displacement, but instead generates high-frequency axial reciprocating stretching vibrations on the order of micrometers (e.g., 10 micrometers to 30 micrometers) in situ, i.e., flutter. This high-frequency vibration energy is directly transmitted to the contact interface between the floating sealing ring 17 and the gate assembly 14 through mechanical contact.

[0053] According to the principles of tribodynamics, high-frequency fretting between contact surfaces has a significant friction-reducing and adhesion-breaking effect. On the one hand, high-frequency tangential and normal fretting transforms the contact state between the sealing surfaces from high-threshold static friction to low-threshold dynamic friction, significantly reducing the equivalent friction coefficient. On the other hand, the alternating stress waves generated by the vibration energy can effectively shatter the bonding nodes, oxide layer, and coking layer between the micro-protrusions of the sealing surface, damaging the cold-welded joint surface. This is similar to striking and vibrating a rusty, tightly fastened nut with a hammer before loosening it, greatly reducing the bonding strength between the interfaces. During this process, the floating sealing ring 17 and the gate assembly 14 are in a critical state of suspension or quasi-separation.

[0054] After maintaining high-frequency flutter for a preset time (e.g., 0.5 to 2 seconds), the intelligent control module controls the DC bias component of the drive current to decrease to zero at a slope. Since the adhesion between the sealing surfaces has been broken and the frictional resistance has been significantly reduced, the elastic potential energy accumulated in the pre-tightened elastic element 24 (such as a high-temperature disc spring assembly) connected in series at the tail of the magnetostrictive drive element 19 is sufficient to overcome the remaining dynamic friction, pushing the magnetostrictive drive element 19 and the floating sealing ring 17 to quickly and smoothly retract into the annular receiving chamber 18. The floating sealing ring 17 actively disengages from the tight contact with the gate assembly 14, creating a small clearance gap before the gate opens.

[0055] For example, in scenario 2: a valve had been operating closed for 3 months at 450℃, and severe thermal seizure was predicted. Upon receiving the opening command, the intelligent control module first cut off the excitation; then, it injected a 1000Hz AC signal with an amplitude of 2A into the drive coil, superimposed on a 5A DC bias. The GMM element generated high-frequency micro-vibration. After 1.5 seconds, the acoustic emission sensor detected a signal indicating interface adhesion failure. Subsequently, the current returned to zero, and the floating sealing ring successfully retracted under the action of the disc spring. The result: the valve opening torque was reduced by 45%, successfully preventing valve stem overload and sealing surface damage.

[0056] Example 7: Magnetorheological fluid 22, as a suspension dispersion system composed of micron-sized magnetic particles, a base fluid, and additives, requires long-term stability for engineering applications. In petrochemical plants, valves may remain stationary for months or even years. Under the influence of gravity, the denser carbonyl iron powder particles (density approximately 7.8 g / cm³) gradually settle from the base fluid (density typically less than 1 g / cm³) to the bottom of the annular containment chamber 18, causing fluid stratification and even the formation of a slab layer at the bottom. Once slab formation occurs, the magnetorheological fluid will fail to produce the expected rheological effect when valve operation is required, or the deposited solid layer may mechanically jam the floating sealing ring 17, leading to complete valve failure and posing a serious safety hazard.

[0057] Therefore, the intelligent control module in this embodiment has a built-in self-maintenance logic for the entire life cycle, and uses the super magnetostrictive element itself as a stirrer, without the need to add an additional mechanism.

[0058] The intelligent control module has an internal non-volatile maintenance timer that records the cumulative time the valve remains stationary (without any action command). When this time reaches a preset maintenance cycle threshold (e.g., every 48 or 72 hours, this parameter is set according to the sedimentation stability index of the selected magnetorheological fluid), the intelligent control module will automatically trigger a fluid disturbance self-maintenance program in the background. Before execution, the module will first detect the current drive current and flow channel pressure to ensure the valve is in a stable stationary state, avoiding intervention while the valve is in process operation.

[0059] The intelligent control module injects a series of specially designed short-duration pulse currents (BurstSignal) into the drive coil 23. This pulse current has the following characteristics: a low frequency (e.g., 10Hz to 30Hz) to ensure a large displacement amplitude; an extremely short duration (e.g., only 3 to 5 seconds per maintenance cycle); and an amplitude strictly limited to a low level (e.g., less than 10% of full-scale current). This weak driving force is insufficient to overcome the static friction of the sealing surface or the preload of the preload elastic element 24, thus preventing macroscopic displacement of the floating sealing ring 17 and avoiding disruption of the valve's current sealing state or media leakage. However, this minute driving force is sufficient to cause the magnetostrictive drive element 19 to reciprocate axially, or breathe, within the microscopic gaps of the annular receiving chamber 18. Because the magnetostrictive drive element 19 is directly immersed in the magnetorheological fluid 22, its micro-movements create localized reciprocating shear flow fields and micro-turbulence within the narrow receiving chamber space. According to the principles of fluid mechanics, this forced flow can effectively break the weak agglomeration structure formed between magnetic particles by van der Waals forces or remanence, and resuspend the particles that have settled to the bottom by lifting them up and entraining them in the carrier liquid.

[0060] While performing micro-stirring, if the hardware supports it, the intelligent control module can also control the excitation coil 21 to output a short-term alternating magnetic field. The changing magnetic field force will disturb the magnetic particles, causing them to rotate or slightly displace in the fluid, further assisting in breaking up the sediment layer. Through this periodic, silent micro-stirring combined with magnetic field disturbance, it is ensured that the magnetorheological fluid 22 in the annular containment chamber 18 always maintains a uniform dispersion state, regardless of how long the valve remains stationary, thereby ensuring that its rheological properties (such as zero-field viscosity and shear yield stress) are always within the design range.

[0061] For example: Scenario 3: A strategic reserve depot's valve has been in a normally closed, standby state for 6 months. Every 72 hours, the intelligent control module automatically wakes up, sending a series of 20Hz triangular wave pulse currents lasting 5 seconds. The magnetostrictive actuation element generates a micro-breathing motion within the containment chamber, agitating the magnetorheological fluid. Judgment result: After regular inductive testing, the magnetorheological fluid maintains good dispersion uniformity, with no caking, ensuring the valve can respond in milliseconds to emergency shut-off signals.

[0062] Example 8: This example illustrates the system integration of the above control method. The self-tightening sealing dynamic compensation gate valve disclosed in this invention essentially constructs an intelligent fluid control terminal with self-sensing, self-adjusting, and self-maintaining capabilities.

[0063] The intelligent control module, as the core hub, integrates a high-precision analog signal acquisition circuit, a power drive circuit, and a complex logic operation unit. It not only executes the aforementioned interlocking, unlocking, and maintenance procedures but also possesses fault diagnosis capabilities. For example, based on single-sample fault diagnosis logic, the intelligent control module continuously monitors the current-pressure response curve of the drive coil 23 during the active pressure build-up phase. If a significant increase in the current required to reach the same sealing pressure is detected, it indicates that the magnetostrictive element may be aging or the magnetorheological fluid performance may be deteriorating. The system will automatically adjust the control parameters (such as increasing the drive current or shortening the maintenance cycle) and report a warning message.

[0064] Based on trend analysis, the system records the average time required for each flutter unlock. If this time shows an upward trend, it indicates that the adhesion of the sealing surface is worsening, and the intelligent control module will automatically increase the amplitude and duration of the flutter signal.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A self-tightening, dynamically compensated gate valve, comprising a valve body (10) and a valve cover (11), wherein the valve body (10) has a through flow channel (12), a valve cavity (13) is located in the middle of the flow channel (12), and a gate assembly (14) is disposed in the valve cavity (13), characterized in that, Also includes: A pair of self-compensating valve seat assemblies (15) are provided in the valve cavity (13). The self-compensating valve seat assembly (15) includes a support ring seat (16) and a floating sealing ring (17). The inner wall of the valve cavity (13) is provided with a stepped hole to facilitate the fixing of the support ring seat (16). The support ring seat (16) is provided with an annular receiving chamber (18) for the installation of the floating sealing ring (17). Magnetorheological fluid (22) is filled in the annular receiving chamber (18). A super magnetostrictive drive element (19) is located in the annular receiving chamber (18) and abuts against the bottom of the floating sealing ring (17) and the annular receiving chamber (18).

2. The self-tightening dynamic compensation gate valve according to claim 1, characterized in that, One end of the floating sealing ring (17) is slidably inserted into the annular receiving chamber (18) in a piston shape, and the other end of the floating sealing ring (17) is provided with a hard alloy sealing layer (20) for cooperating with the sealing surface of the gate assembly (14).

3. The self-tightening dynamic compensation gate valve according to claim 1, characterized in that, An excitation coil (21) is pre-embedded in the support ring seat (16). The excitation coil (21) is arranged around the annular accommodating chamber (18) to apply an adjustable magnetic field to the magnetorheological fluid (22).

4. The self-tightening dynamic compensation gate valve according to claim 3, characterized in that, Multiple magnetostrictive drive elements (19) are evenly distributed around the circumference in the annular receiving chamber (18). Each magnetostrictive drive element (19) is surrounded by a drive coil (23) to generate a drive magnetic field to control the axial elongation of the magnetostrictive drive element (19). A pre-tightening elastic element (24) is connected in series at one end of the magnetostrictive drive element (19) near the bottom of the annular receiving chamber (18). The pre-tightening elastic element (24) is configured to ensure that the magnetostrictive drive element (19) is always subjected to axial compressive stress.

5. The self-tightening dynamic compensation gate valve according to claim 1, characterized in that, A dynamic sealing ring (25) is provided between the outer wall of the floating sealing ring (17) and the inner wall of the annular receiving chamber (18); the end of the floating sealing ring (17) inserted into the annular receiving chamber (18) is truncated cone-shaped, and the bottom of the annular receiving chamber (18) is in the shape of an inner conical hole. The magnetorheological fluid (22) is filled between the conical surface of the floating sealing ring (17) and the inner conical hole surface of the annular receiving chamber (18).

6. The self-tightening dynamic compensation gate valve according to claim 5, characterized in that, The cone angle of the truncated cone is between 15° and 25°.

7. The self-tightening dynamic compensation gate valve according to claim 4, characterized in that, Also includes: The intelligent control module and pressure sensor are provided. The pressure sensor is located at the outlet of the flow channel (12). The excitation coil (21), drive coil (23), and pressure sensor are all electrically connected to the intelligent control module. The intelligent control module is configured as follows: After receiving the first control signal, current is supplied to the drive coil (23), and the super magnetostrictive drive element (19) generates an axial displacement thrust along the sealing direction; After receiving the second control signal, current is supplied to the excitation coil (21), and the magnetorheological fluid (22) switches between a flexible floating state and a rigid locking state to provide variable axial support stiffness for the floating sealing ring (17).

8. The self-tightening dynamic compensation gate valve according to claim 7, characterized in that, The intelligent control module is configured to execute zero-energy interlocking sealing control according to a preset timing logic when it receives the first control signal: The intelligent control module first outputs zero current or low-intensity bias current to the excitation coil (21) to control the magnetorheological fluid (22) to be in a low-viscosity flexible floating state, so as to eliminate the viscous resistance to the movement of the floating sealing ring (17). The intelligent control module supplies driving current to the driving coil (23), controls the super magnetostrictive driving element (19) to generate axial elongation and pushes the floating sealing ring (17) to move toward the gate assembly (14) until a preset sealing pressure ratio is established between the floating sealing ring (17) and the gate assembly (14). Keep the driving current supplied to the driving coil (23) constant, and at the same time supply the saturated excitation current to the excitation coil (21). Use the shear yielding effect of the magnetic field to switch the magnetorheological fluid (22) to a rigid locking state, and fix the floating sealing ring (17) axially through the solidified magnetorheological fluid layer. The intelligent control module gradually reduces and cuts off the current flowing into the drive coil (23). It utilizes the self-locking effect formed by the conical engagement between the magnetorheological fluid (22), which is already in a rigid locked state, and the floating sealing ring (17) to replace the super magnetostrictive drive element (19) in maintaining the axial position and sealing pressure of the floating sealing ring (17), thereby eliminating the thermal decay effect of Joule heat generated by continuous energization on the performance of the super magnetostrictive drive element (19).

9. The self-tightening dynamic compensation gate valve according to claim 7, characterized in that, The intelligent control module is also configured to perform micro-vibration coordinated unlocking control when it receives a valve opening command and generates the second control signal: The intelligent control module first cuts off the current supplied to the excitation coil (21), so that the magnetorheological fluid (22) returns from the rigid locked state to the liquid state, thereby releasing the rigid constraint between the floating sealing ring (17) and the annular accommodating chamber (18); Subsequently, the intelligent control module supplies a composite current superimposed with a high-frequency AC component to the drive coil (23) to drive the super magnetostrictive drive element (19) to generate axial micro-amplitude high-frequency vibration. The axial micro-amplitude high-frequency vibration is used to destroy the static friction bonding layer formed by high temperature and high pressure between the floating sealing ring (17) and the sealing surface of the gate assembly (14), and the floating sealing ring (17) is pushed back into the annular receiving chamber (18) under the restoring force of the pre-tightening elastic element (24).

10. The internally self-tightening dynamic compensation gate valve according to claim 7, characterized in that, The intelligent control module is also configured to execute an anti-settlement self-maintenance procedure when the valve is in a long-term static state: The intelligent control module periodically supplies short-time pulse current to the drive coil (23) according to the preset maintenance cycle, driving the super magnetostrictive drive element (19) to generate micro-movements in the annular accommodating chamber (18); The micro-motion of the super magnetostrictive drive element (19) is used as a stirring source to disturb the magnetorheological fluid (22) filled in the annular containment chamber (18) to prevent the magnetic particles from settling and caking under gravity, and to ensure that the magnetorheological fluid (22) always maintains a uniform dispersion state and controllable rheological properties.

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