Eccentric adjusting ball valve and method for determining eccentric distance

Abstract

The invention discloses an eccentric adjusting ball valve and a method for determining the eccentric distance, and relates to the technical field of valves. The valve core is an eccentric sphere, and an eccentric distance e is formed between the geometric center of the valve core and the rotating center of the valve rod; the eccentric distance e is configured in the mode that when the valve element rotates from the opening position to the closing position, in the adjusting stroke, a scraping gap is formed between the sealing surface of the valve element and the sealing surface of the valve seat, and sealing is achieved through the eccentric wedge pressure effect when the valve element reaches the complete closing position. The valve seat is provided with a double-sealing structure, the valve rod and the valve element are connected through a spline and provided with a limiting structure, and a packing sealing structure comprising a disc spring loading mechanism is arranged between the valve rod and the valve body. Therefore, the eccentric adjusting ball valve can better adapt to complex working conditions, the service life is prolonged, and the adjusting precision and stability are improved.

Description

Technical Field

[0001] This application relates to the field of valve technology, and in particular to an eccentric regulating ball valve and a method for determining the eccentricity. Background Technology

[0002] As a key process control element, the regulating valve regulates the flow rate and pressure of the medium in the pipeline by changing the flow area between the valve core and the valve seat. Although ordinary ball valves have the advantages of large flow capacity and simple structure, their valve cores are usually concentric, and the sealing surface is prone to wear during regulation. Especially when working with high temperature, high viscosity, or media containing fibers or solid particles (such as pulp, suspension, etc.), problems such as sealing failure, jamming, and reduced regulation accuracy are likely to occur, resulting in a shorter service life.

[0003] In existing technologies, ball valves with eccentric structures have emerged to improve sealing performance and service life. However, these eccentric ball valves often have shortcomings in structural integration: either they sacrifice anti-wear performance during regulation in pursuit of a tight seal, leading to premature damage to the sealing surface; or they struggle to maintain the reliability of the seat seal, packing seal, and transmission mechanism when dealing with high-temperature or solid media. Furthermore, insufficient valve stem transmission accuracy and the risk of stem dislodgement under pressure shocks are also common problems in practical applications. Summary of the Invention

[0004] This application provides an eccentric regulating ball valve and a method for determining the eccentricity, thereby solving the problems mentioned in the background art.

[0005] In a first aspect, embodiments of this application provide an eccentric regulating ball valve, comprising a valve body, a valve seat disposed within the valve body, a valve core cooperating with the valve seat to form a sealing pair, and a valve stem driving the valve core to rotate; the valve core is an eccentric ball, and its geometric center has an eccentricity e between it and the rotation center of the valve stem; the eccentricity e is configured such that when the valve core rotates from the open position to the closed position, during the adjustment stroke, a scraping gap is formed between the sealing surface of the valve core and the sealing surface of the valve seat, and a seal is achieved through eccentric wedge pressure when the valve core reaches the fully closed position; the valve seat is provided with a double sealing structure, the valve stem and the valve core are connected by a spline and are provided with a limiting structure, and a packing seal structure including a disc spring loading mechanism is provided between the valve stem and the valve body.

[0006] In conjunction with the first aspect, in one possible implementation, the ratio e / R of the eccentricity e to the radius R of the valve core spherical cap satisfies: 0.08 ≤ e / R ≤ 0.13.

[0007] In conjunction with the first aspect, in one possible implementation, the theoretically calculated value of the scraping gap when the valve opening is 50% is 0.1 mm to 0.3 mm.

[0008] In conjunction with the first aspect, in one possible implementation, the dual sealing structure includes at least two sealing rings, which are pressed and fixed to the valve body by a valve seat pressure ring, wherein at least one sealing ring is a flexible graphite ring and the other sealing ring is a high-temperature resistant elastic material sealing ring.

[0009] In conjunction with the first aspect, in one possible implementation, the limiting structure is an anti-blowout screw arranged along the axial direction of the valve stem.

[0010] In conjunction with the first aspect, in one possible implementation, the packing sealing structure includes, from bottom to top, a packing pad, a double packing, a packing spacer ring, a packing pressure ring, and a packing pressure plate, and the disc spring loading mechanism is provided.

[0011] In conjunction with the first aspect, in one possible implementation, the valve body is a one-piece structure.

[0012] Secondly, embodiments of this application provide a method for determining eccentricity, based on the eccentric regulating ball valve described in the first aspect or any possible implementation of the first aspect, comprising the following steps: S1: Input design parameters and establish a geometric model: Input design parameters, including the flow channel diameter D, the radius R of the valve core spherical crown, the equivalent friction angle ρ of the sealing pair formed by the sealing surface of the valve core and the sealing surface of the valve seat, and the target minimum disengagement clearance δ_min; Establish a geometric model with the geometric center O of the valve core as the origin, and the distance between the geometric center O of the valve core and the rotation center O′ of the valve stem in the geometric model is the eccentricity e to be optimized; S2: Determine the feasible range of eccentricity: Based on the geometric model, determine the upper limit value e_max of eccentricity e to meet the sealing self-locking condition, and determine the lower limit value e_min of eccentricity e according to the target minimum disengagement gap δ_min, so as to determine the feasible design range [e_min,e_max] of eccentricity e. S3: Construct and solve a multi-objective optimization model: Within the feasible design range, construct and solve a multi-objective optimization model with eccentricity e as the optimization variable, thereby determining the optimal eccentricity e_final; wherein, the constraints of the multi-objective optimization model include the formation of a scraping gap between the sealing pairs of the valve during the adjustment stroke, and the optimization objectives include minimizing the operating torque and optimizing the valve flow characteristics, at least one of them.

[0013] In conjunction with the second aspect, in one possible implementation, in step S2, the sealing self-locking condition requires the eccentricity e to satisfy: e≤R×sin(ρ).

[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects: The eccentric regulating ball valve of this application features a scraping gap between the valve core and seat during the regulating stroke. This design effectively reduces wear on the sealing surface, thereby extending the service life of the ball valve. Simultaneously, when the ball valve is in the fully closed position, reliable sealing is achieved through eccentric wedging, effectively balancing wear resistance and sealing performance. The valve seat employs a double-sealing structure, effectively preventing media leakage and enhancing sealing reliability under complex operating conditions. The connection between the valve stem and valve core utilizes a spline connection with a limiting structure. The spline connection accurately transmits torque, improving the transmission accuracy of the valve stem; while the limiting structure prevents the valve stem from dislodging under pressure impact, ensuring stable operation of the ball valve. Furthermore, a packing seal structure with a disc spring loading mechanism is installed between the valve stem and valve body. The disc spring loading mechanism provides stable and continuous sealing pressure, ensuring the packing always maintains a good sealing state, effectively preventing leakage under complex media conditions and improving the reliability of the packing seal. Therefore, the eccentric regulating ball valve of this application can better adapt to complex working conditions, extend service life, and improve regulating accuracy and stability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the eccentric regulating ball valve provided in the embodiments of this application; Figure 2 for Figure 1 Enlarged view of section A in the image; Figure 3 This is a schematic diagram of the double sealing structure provided in the embodiments of this application; Figure 4 The eccentricity calculation model provided in the embodiments of this application; Figure 5 Comparison of optimized design flow capacity CV and ideal flow capacity CV provided in the embodiments of this application; Figure 6 A schematic diagram of the dynamic rotation angle of the FD9 valve core provided in the embodiments of this application.

[0017] Icons: 1-Valve body; 2-Valve seat; 21-Double sealing structure; 211-Sealing ring; 3-Valve stem; 4-Limiting structure; 41-Anti-blowout screw; 5-Packing seal structure; 51-Packing gasket; 52-Double packing; 53-Packing spacer ring; 54-Packing pressure ring; 55-Packing pressure plate; 56-Disc spring loading mechanism; 6-Actuator; 7-Valve core; 8-Valve seat pressure ring. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0020] This application provides an eccentric regulating ball valve, such as Figures 1 to 6 As shown in the figure. This application provides an eccentric regulating ball valve, including a valve body 1, a valve seat 2 disposed within the valve body 1, a valve core 7 that cooperates with the valve seat 2 to form a sealing pair, and a valve stem 3 that drives the valve core 7 to rotate. The valve core 7 is an eccentric ball, and its geometric center has an eccentricity e between it and the rotation center of the valve stem 3. The eccentricity e is configured such that when the valve core 7 rotates from the open position to the closed position, a scraping gap is formed between the sealing surface of the valve core 7 and the sealing surface of the valve seat 2 during the regulating stroke, and a seal is achieved through eccentric wedge pressure when the valve core 7 reaches the fully closed position. The valve seat 2 is provided with a double sealing structure 21, the valve stem 3 and the valve core 7 are connected by a spline and are provided with a limiting structure 4, and a packing seal structure 5 including a disc spring loading mechanism 56 is provided between the valve stem 3 and the valve body 1.

[0021] It should be noted that in the eccentric regulating ball valve of this application, a scraping gap is formed between the valve core 7 and the valve seat 2 during the regulating stroke. This design effectively reduces wear on the sealing surface, thereby extending the service life of the ball valve. Simultaneously, when the ball valve is in the fully closed position, reliable sealing is achieved through eccentric wedge pressure, effectively balancing wear resistance and sealing performance. The valve seat 2 of this ball valve adopts a double sealing structure 21, which effectively prevents media leakage and enhances sealing reliability under complex operating conditions. In the connection design between the valve stem 3 and the valve core 7, a spline connection method is adopted and a limiting structure 4 is set. The spline connection can accurately transmit torque, improving the transmission accuracy of the valve stem 3; while the limiting structure 4 can prevent the valve stem 3 from dislodging under pressure impact, ensuring the stable operation of the ball valve. Furthermore, a packing seal structure 5 with a disc spring loading mechanism 56 is set between the valve stem 3 and the valve body 1. The disc spring loading mechanism 56 can provide stable and continuous sealing pressure, ensuring that the packing always maintains a good sealing state, effectively preventing leakage under complex media conditions, and improving the reliability of the packing seal. Therefore, the eccentric regulating ball valve of this application can better adapt to complex working conditions, extend service life, and improve regulating accuracy and stability.

[0022] In this embodiment, the ratio e / R of the eccentricity e to the radius R of the spherical crown of the valve core 7 satisfies: 0.08 ≤ e / R ≤ 0.13. This ratio range is determined based on a comprehensive balance consideration of valve adjustment performance, sealing performance, and wear life. If the e / R ratio is too small (e.g., less than 0.08), the eccentricity e is relatively insufficient. During the adjustment stroke of the valve core 7 rotating from open to closed, it is difficult to form a sufficiently significant scraping separation gap between the sealing surface of the valve core 7 and the sealing surface of the valve seat 2. The contact pressure between the two is still relatively large, which leads to increased wear on the sealing surface of the valve seat 2 during the adjustment process, which is not conducive to extending the service life of the valve under frequent adjustment conditions. If the e / R ratio is too large (e.g., greater than 0.13), although the gap in the adjustment stroke is larger, when the valve core 7 rotates to the fully closed position, the required wedge pressure closing angle may be difficult to control precisely due to the excessive eccentricity e, or the contact stress distribution between the valve core 7 and the valve seat 2 at the final sealing may be uneven, which may affect the reliability and stability of the seal, or even cause jamming. Therefore, limiting the e / R ratio within the aforementioned range ensures that during the regulating stroke, the valve core 7 and valve seat 2 effectively disengage or maintain only minimal contact force, significantly reducing friction and wear. Upon reaching the closed position, a reasonable eccentricity e is utilized to precisely wed the valve core 7 into the valve seat 2 via the torque of the valve stem 3, generating sufficient and uniform sealing pressure to achieve a reliable zero-leakage seal. In a preferred embodiment, the e / R ratio is 0.1, at which a better balance is achieved between regulating characteristics and sealing performance.

[0023] In this embodiment, the theoretically calculated value of the scraping gap when the valve opening is 50% is 0.1mm to 0.3mm.

[0024] It should be noted that controlling the theoretical value of the scraping gap at 50% opening to 0.1mm to 0.3mm can ensure that the sealing pair is completely disengaged or has only a very small risk of contact in most adjustment ranges, thereby substantially avoiding wear on the sealing surface.

[0025] In this embodiment, the sealing surface of the valve core 7 is hardened to improve its wear resistance, erosion resistance and scratch resistance.

[0026] In the embodiments of this application, such as Figure 1 and Figure 3 As shown, the double sealing structure 21 includes at least two sealing rings 211. The sealing rings 211 are pressed and fixed inside the valve body 1 by the valve seat pressure ring 8. At least one sealing ring 211 is a flexible graphite ring, and the other sealing ring 211 is a high-temperature resistant elastic material sealing ring.

[0027] It should be noted that the flexible graphite ring, with its excellent high-temperature stability, self-lubrication, and compensation capabilities, ensures the basic sealing reliability under temperature fluctuations and long-term operation; while the high-temperature resistant elastic material sealing ring provides good initial sealing fit and media adaptability. The combined use of the flexible graphite ring and the high-temperature resistant elastic material sealing ring not only improves the overall sealing performance and lifespan of the valve seat 2 under high-temperature conditions and effectively prevents leakage caused by the failure of a single material, but also enhances its tolerance to complex media containing particles, fibers, etc., thereby directly solving the problem in the background technology that "it is difficult to ensure the sealing reliability of the valve seat 2 when dealing with high-temperature and solid media."

[0028] In this embodiment, the limiting structure 4 is an anti-push-out screw 41 arranged along the axial direction of the valve stem 3, which eliminates the safety hazard of the valve stem 3 axially dislodging under the pressure impact of the internal medium or under the condition of misoperation.

[0029] In the embodiments of this application, such as Figure 1 and Figure 2 As shown, the packing sealing structure 5 includes a packing pad 51, a double packing 52, a packing spacer ring 53, a packing pressure ring 54 and a packing pressure plate 55 arranged sequentially from bottom to top, and a disc spring loading mechanism 56 is arranged above the packing pressure plate 55.

[0030] Specifically, the disc spring loading mechanism 56 of this application can provide stable and continuous sealing pressure for the packing, effectively preventing media leakage and ensuring the reliability of the packing seal under alternating temperature conditions.

[0031] It should be noted that the packing seal structure 5 provided in this embodiment, through a hierarchical arrangement of "packing pad 51 - double packing 52 - packing spacer 53 - packing pressure ring 54 - packing pressure plate 55", and supplemented by a disc spring loading mechanism 56 disposed above the packing pressure plate 55, jointly constructs a dynamic sealing system with continuous self-compensation capability. In this structure, the double packing 52 improves sealing redundancy, the packing spacer 53 helps with pressure equalization and heat dissipation, and the core function of the disc spring loading mechanism 56 is to automatically and continuously compensate for the attenuation of clamping force caused by packing wear, temperature changes, or vibration. This design ensures the long-term reliability of the packing seal at the valve stem 3 points under long-term operation and operating condition fluctuations, effectively preventing external leakage of the valve, thereby directly enhancing the overall sealing stability and safety of the valve under the harsh operating conditions described in the background art.

[0032] In this embodiment, the valve body 1 is an integral structure. This design eliminates the common connecting flanges and bolts of split valve bodies 1, eliminates the risk of leakage that may occur in the middle of the valve body 1 due to the connection interface, and improves the overall structural integrity and pressure resistance of the valve.

[0033] Specifically, the upper end of the valve stem 3 is connected to the actuator 6 via a spline.

[0034] One of the core innovations of this application's embodiments lies in the geometric design of the valve core 7 and its mating relationship with the valve stem 3. For example... Figure 4 As shown, the geometric center O of the valve core 7 does not coincide with the rotation center O′ of the valve stem 3; there is a precisely calculated and optimized eccentricity e between them.

[0035] The configuration of this eccentricity e follows a scientific design methodology, the core of which lies in achieving the following key functions through geometric and mechanical models: A scraping gap is formed during the adjustment stroke: When the actuator 6 drives the valve stem 3 and valve core 7 to rotate from the open position to the closed position, due to the eccentricity e, a controllable scraping gap is formed between the sealing surface of the valve core 7 and the sealing surface of the valve seat 2. This gap can effectively avoid direct friction and wear of the sealing pair during the adjustment process, significantly extending the service life of the valve.

[0036] Achieving eccentric wedge pressure seal in the closed position: When the valve core 7 rotates to the fully closed position, the eccentric structure causes the spherical crown part to mechanically wedge into the sealing surface of the valve seat 2 under the action of the torque of the valve stem 3, generating sufficient contact stress, thereby achieving a reliable zero-leakage shut-off seal.

[0037] This application provides a method for determining eccentricity. By establishing a precise geometric and mechanical model, and combining multi-objective optimization and experimental verification, the optimal eccentricity is scientifically determined. This method aims to simultaneously ensure reliable valve sealing, low operating torque, excellent flow characteristics, and low wear during operation. The method specifically includes the following steps S1 to S3.

[0038] Step S1: Input design parameters and establish geometric model Input the core design parameters, including: flow channel diameter D, spherical crown radius R of valve core 7, equivalent friction angle ρ of the sealing pair formed by valve core 7 and valve seat 2 (a comprehensive characterization parameter of the friction characteristics between the sealing surface of valve core 7 and the sealing surface of valve seat 2), initial valve opening angle θ_open (such as the rotation angle corresponding to 5% opening), and the target minimum disengagement gap δ_min to be achieved at this angle (i.e., the minimum gap threshold for effective disengagement of the sealing pair, δ_min>0).

[0039] The following geometric model is established for analysis: 1. Coordinate system definition: A Cartesian coordinate system is established with the geometric center O of valve core 7 (sphere) as the origin (see...). Figure 4 ); 2. Key point coordinates: The rotation center O′ of valve stem 3 is located on the Y-axis with coordinates (0, e), where e is the eccentricity to be optimized (e>0, satisfying OO′=e); The initial contact point P of the sealing pair (corresponding to the fully closed valve position) is located on the intersection line of the flow channel diameter D and the theoretical spherical surface of the valve core; 3. Basic geometric relationship: The coordinates (x, y) of point P simultaneously satisfy: (1) Equation of the sphere: x² + y² = R².

[0040] (2) Relationship of rotation radius: The distance from point P to the rotation center O′ is a constant r (rotation radius): x² + (ye)² = r².

[0041] 4. Motion transformation and definition of clearance / interference: When the valve core 7 rotates around O′ angle When point P moves to a new position P′(x′, y′), the clearance / interference condition of the sealing pair is calculated as follows: (1) Coordinate transformation calculation: First, calculate the initial phase angle α = arcsin((ye) / r) of point P relative to the rotation center O′. Then, obtain the coordinates of P′ after rotation. x′=r×cos(α-θ), y′=r×sin(α-θ)+e.

[0042] (2)Definition and calculation of clearance / interference δ(θ): The distance R′ from point P′ to the geometric center O of the valve core is .

[0043] Define the theoretical clearance / interference of the sealing pair as: δ(θ) = R - R′; Physical meaning: When δ(θ) > 0, it means R′ < R, point P′ is inside the theoretical spherical surface, and there is a clearance of size δ(θ) between the valve core 7 and the valve seat 2.

[0044] When δ(θ) < 0, it means R′ > R, point P′ is outside the theoretical spherical surface, and there is an interference (sealing compression amount) of size ∣δ(θ)∣ between the valve core 7 and the valve seat 2.

[0045] Special note: The "target minimum unseating clearance δ_min" input in step S1 is the preset target value of δ(θ) when θ = θ_open, that is, it is required that δ(θ_open) = δ_min (to ensure the effective unseating of the sealing pair at the initial stage of opening).

[0046] Step S2: Determine the feasible range of the eccentricity Based on the geometric model in step S1, determine the feasible design range [e_min, e_max] of the eccentricity e through double constraints to ensure the sealing reliability and anti-wear performance: 1. Determine the upper limit value e_max (based on the sealing self-locking condition): To prevent the valve from being pushed open by the medium pressure when the valve is fully closed, it is necessary to meet the sealing self-locking condition: the eccentricity e ≤ R × sin(ρ) (ρ is the equivalent friction angle of the sealing pair); Therefore, the upper limit value of the eccentricity e_max = R × sin(ρ); 2. Determine the lower limit value e_min (constraint of the minimum unseating clearance): To ensure that the sealing pair reaches the preset target minimum unseating clearance δ_min at the initial opening angle θ_open of the valve, substitute θ = θ_open and δ(θ_open) = δ_min into the δ(θ) calculation formula in step S1, and solve for the minimum eccentricity e_min that meets this condition reversely; Logical basis: If e < e_min, then δ(θ_open) < δ_min, and the sealing pair cannot be effectively unseated, and wear is likely to occur during the adjustment stroke; if e ≥ e_min, then δ(θ_open) ≥ δ_min, meeting the basic requirements for anti-wear; 3. Feasible design range: Considering the above constraints, the feasible range of e is [e_min, e_max]; Preferred embodiment: To balance adjustment accuracy, sealing reliability and wear life, the final optimized eccentricity e must satisfy e / R∈[0.08, 0.13]; within this range, when the valve opening is 50%, the theoretical scraping clearance δ(50%)∈[0.1mm, 0.3mm] of the sealing pair can minimize friction of the sealing surface during the adjustment process.

[0047] S3: Construct and solve the multi-objective optimization model: Within the feasible interval [e_min, e_max], a multi-objective optimization model is constructed with the eccentricity e as the optimization variable, and the optimal eccentricity e_final with comprehensive performance is solved: Optimization objective (at least one of the following must be met): (1) Minimize operating torque: The resistance torque of the fluid pressure difference Δp acting on the valve core is approximately Mf≈Δp×(π / 4×D²)×(e+0.25d) (d is the diameter of valve stem 3). By reducing e, the driving load is reduced and the ease of operation is improved. (2) Optimize flow characteristics: By adjusting e, the relationship between valve opening and flow area (i.e., the opening-flow capacity CV value curve) is made smooth and continuous, and approaches the ideal regulation characteristics (such as equal percentage characteristics), thereby improving the accuracy of flow control; Core constraints: (1) Scraping gap constraint: Within the main adjustment stroke (such as opening 10%~80%, corresponding to rotation angle θ1~θ2), it is necessary to ensure δ(θ)>0 to realize the "scraping" non-contact movement of the sealing pair and avoid wear; (2) Sealing interference constraint: When the valve is fully closed (θ=θ_close), it is necessary to ensure that δ(θ_close)<0, and generate sufficient sealing pressure through the interference to achieve zero leakage sealing; 3. Optimization and Verification: By applying multi-objective optimization algorithms (such as the weighted method and Pareto front solution), the above model can be solved. Within the feasible range, the optimal eccentricity e_final, which best balances multiple performance indicators such as low operating torque, excellent flow characteristics, low wear (scraping clearance), and reliable sealing, can be found. To verify the effectiveness of this design method, performance tests were conducted on the valve prototype manufactured using this method with the determined eccentricity e. The results are shown in Table 1.

[0048] Table 1 Valve performance test data

[0049] like Figure 5As shown, the optimized design flow capacity CV value (the "Design CV" curve in the figure) and the ideal flow capacity CV value (the "Ideal CV" curve in the figure) exhibit a high degree of overlap. Combined with the measured data in Table 1, it can be seen that the valve optimized by the method described in this application maintains a smooth and continuous trend in its design flow capacity CV value within the full opening range of 10% to 100%, without any sudden changes or fluctuations, and its numerical value highly matches the preset ideal flow capacity CV value. This result fully verifies the scientific nature and effectiveness of this design method—by using the eccentricity e as the core optimization variable, combined with constraints such as sealing self-locking and scraping gap, and a multi-objective design logic that minimizes operating torque and optimizes flow characteristics, the controllable design of the valve's flow regulation characteristics can be accurately achieved. Ultimately, this enables the valve to possess excellent, stable, and accurately predictable flow regulation performance, meeting the stringent requirements for flow control accuracy under complex operating conditions.

[0050] In practical work, such as Figure 6 As shown, the actuator 6 drives the valve stem 3 and valve core 7 to rotate, achieving precise flow regulation by continuously changing the flow area. Thanks to the optimized eccentricity e achieved by the above method, a protective micro-gap (scraping gap) is formed between the valve core 7 and the valve seat 2 during the adjustment process, effectively avoiding direct frictional wear of the sealing surface. When the valve rotates to the closed position, the necessary interference fit is generated, achieving reliable wedge pressure sealing. As shown in Table 1, during the opening change from 10% to 100%, the valve's mass flow rate and design flow capacity CV value increase smoothly and continuously without abrupt changes, demonstrating its excellent regulatory linearity and controllability. This set of measured data is highly consistent with the design expectations derived from the aforementioned geometric model and multi-objective optimization, fully verifying the correctness and engineering applicability of the design method disclosed in this application.

[0051] This application provides a complete technical solution from scientific design to performance verification by combining theoretical models (precise geometric and mechanical formulas), explicit design constraints (self-locking conditions, minimum disengagement clearance), multi-objective optimization of the system (balancing operating torque and flow characteristics), and empirical performance testing. This solution successfully resolves the long-standing contradiction between wear and sealing reliability faced by control valves under harsh operating conditions, providing a reliable path to achieving long-life, high-precision flow control.

[0052] It should be noted that the eccentricity design method disclosed in this application transforms the design of valve core parameters from the traditional experience-based "trial and error" model to a scientific calculation and optimization model based on mathematical models and clear optimization objectives. This method not only accurately predicts valve performance under different operating conditions, significantly shortening the design cycle and reducing R&D costs, but also provides a solid theoretical basis and tools for continuous performance improvement and iterative optimization of products. Ultimately, this solution successfully provides a complete solution for an eccentric regulating ball valve that is structurally sound, reliably sealed, precisely adjustable, and particularly suitable for harsh media such as high-temperature, high-viscosity, and fibrous media.

[0053] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0054] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. An eccentrically-adjusted ball valve, characterized by, The valve body (1), the valve seat (2) arranged in the valve body (1), the valve core (7) cooperating with the valve seat (2) to form a sealing pair, and the valve stem (3) driving the valve core (7) to rotate are comprised; The valve core (7) is an eccentric sphere, and the geometric center and the rotation center of the valve stem (3) have an eccentricity e; the eccentricity e is configured to form a scraping gap between the sealing surface of the valve core (7) and the sealing surface of the valve seat (2) in the adjustment stroke when the valve core (7) rotates from the open position to the closed position, and to achieve sealing by eccentric wedge pressure when reaching the fully closed position; The valve seat (2) is provided with a double sealing structure (21), the valve stem (3) and the valve core (7) are connected by a spline and provided with a limiting structure (4), and the valve stem (3) and the valve body (1) are provided with a packing seal structure (5) comprising a disc spring loading mechanism (56).

2. The eccentrically-adjusted ball valve according to claim 1, characterized in that, The ratio e / R of the eccentricity e to the spherical cap radius R of the valve core (7) satisfies: 0.08≤e / R≤0.

13.

3. The eccentrically-adjusted ball valve according to claim 1, wherein The theoretical calculation value of the scraping gap when the valve opening is 50% is 0.1mm to 0.3mm.

4. The eccentrically-adjusted ball valve according to claim 1, wherein The double sealing structure (21) comprises at least two sealing rings (211), and the sealing rings (211) are fixed in the valve body (1) by a valve seat pressing ring (8), wherein at least one sealing ring (211) is a flexible graphite ring, and the other sealing ring (211) is a high-temperature-resistant elastic material sealing ring.

5. The eccentrically-adjusted ball valve according to claim 1, wherein The limiting structure (4) is a anti-bump-out screw (41) arranged axially along the valve stem (3).

6. The eccentrically-adjusted ball valve according to claim 1, wherein, The packing seal structure (5) comprises, from bottom to top, a packing pad (51), a double packing (52), a packing spacer ring (53), a packing pressing ring (54), and a packing pressing plate (55), and the disc spring loading mechanism (56) is arranged above the packing pressing plate (55).

7. The eccentrically-adjusted ball valve according to claim 1, wherein The valve body (1) is an integral structure.

8. A method of determining an eccentricity, characterized by, The eccentric regulating ball valve according to any one of claims 1-7, comprising the following steps: S1: input design parameters and establish a geometric model: input design parameters, the design parameters including flow passage diameter D, valve core (7) spherical cap radius R, equivalent friction angle ρ of the sealing pair formed by the sealing surface of the valve core (7) and the sealing surface of the valve seat (2), and target minimum lift-off gap δ_min; a geometric model with the geometric center O of the valve core (7) as the origin is established, and the distance between the geometric center O of the valve core (7) and the rotation center O' of the valve stem (3) in the geometric model is the eccentricity e to be optimized; S2: determine the feasible interval of eccentricity: based on the geometric model, determine the upper limit value e_max of the eccentricity e to meet the sealing self-locking condition, and determine the lower limit value e_min of the eccentricity e according to the target minimum lift-off gap δ_min, to determine the feasible design interval [e_min, e_max] of the eccentricity e; S3: constructing and solving a multi-objective optimization model: in the feasible design interval, taking the eccentricity e as the optimization variable, constructing and solving a multi-objective optimization model, so as to determine the optimal eccentricity e_final; wherein the constraint conditions of the multi-objective optimization model include that the scraping gap is formed between the sealing pairs in the adjusting stroke of the valve, and the optimization objectives include at least one of minimizing the operating torque and optimizing the flow characteristics of the valve.

9. The method of determining eccentricity according to claim 8, characterized in that, In step S2, the sealing self-locking condition requires that the eccentricity e satisfies: e≤R×sin(ρ).

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