Ball valve plug with high cavitation suppression and ball valve

Abstract

The application discloses a ball valve core capable of efficiently inhibiting cavitation and a ball valve, and relates to the technical field of valves. The ball valve structure can inhibit the development of cavitation. The outlet of the ball valve core is designed as double-stage throttle holes to inhibit cavitation. The first-stage throttle hole generates an initial pressure drop of fluid and reduces the kinetic energy at the jet core. The second-stage throttle hole reconstructs the pressure gradient field of the fluid and reduces the maximum pressure gradient. While reducing the flow velocity in the jet area, the pressure of the fluid flowing through the variable cross-section at the outlet of the valve core is increased, so that only a small amount of fluid has a pressure lower than the saturated steam pressure at the outlet of the valve core, and therefore the spatial distribution of cavitation bubbles is more discrete. The valve core serves as a jet outlet. The first-stage throttle hole and the second-stage throttle hole are sequentially arranged on the jet surface of the outlet of the valve core along the fluid flow direction, so that cavitation is inhibited, and problems such as cavitation erosion and vibration caused by cavitation are reduced.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a ball valve core and a ball valve that can effectively suppress cavitation. Background Art

[0002] Valves are industrial devices used in pressure pipelines. Their function is to change the cross-section of the pipeline and the direction of the medium's flow, thereby controlling parameters such as pressure, flow, and temperature. As a key component in industrial piping systems, valves play an irreplaceable and important role in various sectors of the national economy. In the transportation sector, this includes locomotives, aircraft, and motor vehicles; in the field of national defense science and technology, they involve atomic energy, the nuclear industry, launch vehicles, and spacecraft.

[0003] Ball valves are a key valve widely used in liquid storage and transportation equipment management systems. They offer excellent performance, including flexible opening and closing, reliable sealing, and safe and stable operation. They are particularly suitable for conveying and controlling media such as ethylene, liquid oxygen, liquid hydrogen, liquefied natural gas, and liquefied petroleum products. These valves offer a variety of actuation modes to meet diverse operating requirements, including manual, electric, pneumatic, and worm gear drives. Users can choose the appropriate drive based on their specific operating environment and control requirements. By properly selecting a ball valve and its actuation mode, efficient and precise control of the media can be achieved, ensuring the safe and stable operation of storage and transportation systems.

[0004] Cavitation is a phase transition from liquid to gas when the local pressure of a liquid drops below its saturated vapor pressure. This phenomenon is common in engineering fields such as fluid transportation systems and underwater vehicle motion, and is a key factor affecting equipment operational stability. During valve operation, cavitation can significantly reduce control performance, leading to flow instability and excessive energy loss. It can also induce vibration and noise, impacting the reliability and service life of the entire system.

[0005] Currently, valve cavitation suppression primarily relies on traditional methods such as step-by-step pressure reduction and orifice throttling. For globe and butterfly valves, cavitation can be effectively suppressed by optimizing the valve core end face structure or improving the disc structure without affecting flow performance. However, for ball valves, designing a cavitation-suppressing valve core structure while maintaining the original flow performance presents significant technical challenges, resulting in a relative lack of research on ball valve cavitation suppression both domestically and internationally. Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a ball valve core and a ball valve that can effectively suppress cavitation, so as to solve the problem in the related art that a high-speed jet area is formed at the upper edge of the valve core outlet, resulting in cavitation in the local low-pressure area, and to suppress the development of cavitation, reduce vibration and noise during equipment operation, and damage to the valve.

[0007] According to the first aspect of the embodiment of the present application, a ball valve core is provided for efficiently suppressing cavitation, wherein the outlet of the ball valve core is designed as a two-stage throttling hole for suppressing cavitation, wherein the first-stage throttling hole generates an initial pressure drop on the fluid, reducing the kinetic energy at the jet core; the second-stage throttling hole reconstructs the pressure gradient field of the fluid, reducing the maximum pressure gradient; through the setting of the two-stage throttling hole, while reducing the flow velocity in the jet area, the pressure of the fluid flowing through the variable cross-section of the valve core outlet is increased, so that only a small amount of fluid pressure is lower than the saturated vapor pressure at the valve core outlet, thereby making the spatial distribution of cavitation more discrete; the valve core serves as a jet outlet, and the first-stage throttling hole and the second-stage throttling hole are located successively on the jet surface of the valve core outlet along the fluid flow direction.

[0008] Optionally, there are at least 16 first-stage throttling holes.

[0009] Optionally, there are at least 24 second-stage throttling holes.

[0010] Optionally, the distance between the central section where the first-stage throttling hole is located and the central section where the second-stage throttling hole is located is 60-80 mm.

[0011] Optionally, the distance between the central section where the first-stage throttling hole is located and the central plane of the ball valve core is 120~180mm.

[0012] Optionally, the distance between the central section where the second-stage throttling hole is located and the central plane of the ball valve core is 200~250mm.

[0013] According to a second aspect of an embodiment of the present application, a ball valve for efficiently suppressing cavitation is provided, comprising a valve body and a ball valve core mounted on the valve body, wherein the ball valve core is the ball valve core for suppressing cavitation described in the first aspect.

[0014] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0015] As can be seen from the above embodiments, the outlet of the ball valve core described in the present application is designed as a bipolar throttling hole to suppress cavitation; the valve core serves as a jet outlet, and the modified structure changes the flow pattern at the valve core outlet through a diversion mechanism, so that the fluid can achieve flow velocity gradient control before passing through the variable cross-section area. It can effectively suppress the generation and development of cavitation, thereby reducing the erosion and damage of cavitation to the valve. The distribution of the low-pressure area at the valve core outlet is significantly reduced, and the low-pressure area at the lower edge of the valve core outlet basically disappears. This is because the two-stage throttling hole inside the valve core changes the flow characteristics of the fluid in advance. The initial pressure drop caused by the first-stage throttling hole on the fluid reduces the kinetic energy at the core of the jet. The second-stage throttling hole reconstructs the pressure gradient field of the fluid and reduces the maximum pressure gradient.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] Figure 1 The figure is a side view of a ball valve core for efficiently suppressing cavitation according to an exemplary embodiment.

[0019] Figure 2 The figure is a right side view of a ball valve core that effectively suppresses cavitation according to an exemplary embodiment.

[0020] Figure 3 for Figure 1 AA cross-sectional view of the .

[0021] Figure 4 FIG. 1 is a cross-sectional view of a ball valve for efficiently suppressing cavitation according to an exemplary embodiment.

[0022] Figure 5 Figure 2 is a cavitation volume fraction comparison cloud diagram showing the cavitation suppression effect according to an exemplary embodiment, wherein (a) is a cavitation volume fraction isosurface cloud diagram of a ball valve without a cavitation suppression structure, and (b) is a cavitation volume fraction isosurface cloud diagram of a ball valve with a cavitation suppression structure. DETAILED DESCRIPTION

[0023] Exemplary embodiments will be described in detail herein, with examples shown in the accompanying drawings. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0024] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0025] When conventional ball valves are fully opened, severe cavitation can occur near the valve core outlet, reducing the valve's regulating characteristics, increasing flow instability, and causing unnecessary energy loss. Cavitation can also cause vibration and noise during operation. The present invention aims to provide a highly efficient cavitation-suppressing ball valve core. This structure effectively inhibits the occurrence and development of cavitation, improves valve flow stability, and reduces damage to the valve caused by cavitation.

[0026] refer to Figure 1-Figure 3 , this embodiment provides a ball valve core that effectively suppresses cavitation. The ball valve core is designed as a two-stage throttling hole to suppress cavitation. The first-stage throttling hole 3 generates an initial pressure drop on the fluid, reducing the kinetic energy at the core of the jet. The second-stage throttling hole 4 reconstructs the pressure gradient field of the fluid and reduces the maximum pressure gradient. By setting up two-stage throttling holes, while reducing the flow velocity in the jet area, the pressure of the fluid flowing through the variable cross-section of the valve core outlet is increased, so that only a small amount of fluid pressure is lower than the saturated vapor pressure at the valve core outlet, so that the spatial distribution of cavitation is more discrete. The valve core serves as a jet outlet, and the first-stage throttling hole 3 and the second-stage throttling hole 4 are located on the jet surface of the valve core outlet in sequence along the direction of fluid flow.

[0027] In this embodiment, the first-stage throttle holes have at least 16 holes, evenly spaced along the circumference to form a ring shape; the second-stage throttle holes have at least 24 holes, evenly spaced along the circumference to form a ring shape. This does not affect the overall flow performance of the ball valve, effectively suppressing cavitation without significantly affecting the flow field structure and valve flow performance.

[0028] In this embodiment, the distance between the center section of the first-stage throttle hole 3 and the center section of the second-stage throttle hole 4 is 60-80 mm. The distance between the center section of the first-stage throttle hole 3 and the center plane of the ball valve core is 120-180 mm. The distance between the center section of the second-stage throttle hole 4 and the center plane of the ball valve core is 200-250 mm.

[0029] In this embodiment, a dual-stage orifice design is employed at the valve core outlet. When the fluid flows through the variable cross-section area, fluid resistance is concentrated, making it more likely to produce a jet. This modified structure alters the flow pattern at the valve core outlet through a diversion mechanism, enabling velocity gradient control before the fluid passes through the variable cross-section area, thus reducing the occurrence of localized cavitation. The high-frequency region of cavitation evolution is located at the valve core outlet, so designing a throttling orifice at the outlet helps suppress cavitation.

[0030] Figure 4This is a cross-sectional view of a ball valve structure that effectively suppresses cavitation, according to an exemplary embodiment. The valve body 1 includes a valve core 2 mounted on the valve body 1. To suppress cavitation in the ball valve, the valve core 2 is designed as a bipolar orifice to inhibit cavitation and serve as a jet outlet. When the valve is closed, the inlet and outlet surfaces of the valve core 2 are at a 90-degree angle to the pipeline inlet and outlet, preventing fluid from passing through the valve core 2. In this state, the fluid passage is closed. When the ball valve core 2 is fully opened, fluid flows through the variable cross-section at the outlet of the valve core 2, forming a jet. This rapidly increases the fluid flow rate, causing a decrease in the local pressure at the outlet of the valve core 2. When the pressure at the outlet of the valve core 2 drops below the saturated vapor pressure, cavitation occurs. The design of the first-stage orifice 3 and second-stage orifice 4 at the outlet of the valve core 2 effectively slows the fluid flow rate without changing the outlet flow rate. As the flow rate at the outlet of the valve core 2 decreases, the local pressure at this location increases. When the local pressure exceeds the saturated vapor pressure, cavitation is suppressed.

[0031] refer to Figure 5 Cavitation flow field simulations were conducted on a ball valve with high-efficiency cavitation suppression and a ball valve without a cavitation suppression structure under the same operating conditions and openings. The valve has 16 first-stage orifices and 24 second-stage orifices. The distance between the center section of the first-stage orifice and the center section of the second-stage orifice is 70 mm. The distance between the center section of the first-stage orifice and the center plane of the ball valve core is 150 mm, and the distance between the center section of the second-stage orifice and the center plane of the ball valve core is 220 mm. Figure 5 Figure (a) shows the cavitation evolution process inside a ball valve without a cavitation suppression structure. T represents a complete cavitation evolution cycle, and the cavitation evolution cycle inside the ball valve is divided into six moments. At t = 1 / 6T, the cavitation is in the development stage. The cavitation separation and collapse stage occurs from t = 2 / 6T to 4 / 6T. As the cavitation flow field continues to develop, the development cycle reaches the secondary separation and collapse and development stages from t = 5 / 6T to 6 / 6T. As can be seen from the figure, under this operating condition, cavitation develops violently, the cavitation volume is large, and the cavitation cloud separated from the front of the cavitation is more likely to collapse. Figure 5 (b) is the cavitation evolution process inside the ball valve with a double-stage throttle hole structure that inhibits cavitation development. Figure 5 From (a) and (b), it can be seen that the cavitation volume generated at the outlet of the ball valve core 2 of the present invention is smaller, no large-scale cavitation is observed, and the overall cavitation distribution is relatively discrete, the cavitation development cycle is shorter, and the displacement distance of the cavitation is effectively suppressed. This also confirms that the ball valve core 2 of the present invention that suppresses cavitation has a good inhibitory effect on cavitation.

[0032] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the application embrace any and all variations of the present application that fall within the scope of the general inventive concept as defined by the appended claims and their equivalents. The specification and examples are to be considered exemplary only, with the true scope and spirit of the application indicated by the claims.

[0033] It is to be understood that the application is not limited to the precise construction herein described and as shown in the attached drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is to be defined by the claims appended hereto.

Claims

1. A ball valve core with high efficiency in suppressing cavitation, characterized in that: The outlet of the ball valve core is designed as a two-stage throttle hole to suppress cavitation. The first-stage throttle hole generates an initial pressure drop on the fluid, reducing the kinetic energy at the core of the jet; the second-stage throttle hole reconstructs the pressure gradient field of the fluid and reduces the maximum pressure gradient; while reducing the flow velocity in the jet area, it increases the pressure of the fluid flowing through the variable cross-section of the valve core outlet, so that only a small amount of fluid pressure at the valve core outlet is lower than the saturated vapor pressure, thereby making the spatial distribution of cavitation more discrete; the valve core serves as a jet outlet, and the first-stage throttle hole and the second-stage throttle hole are located sequentially on the jet surface of the valve core outlet along the fluid flow direction; There are at least 16 first-stage throttling holes, which are evenly arranged along the circumferential direction to form a ring shape; there are at least 24 second-stage throttling holes, which are evenly arranged along the circumferential direction to form a ring shape.

2. The ball valve core for efficiently suppressing cavitation according to claim 1, characterized in that: The distance between the central section where the first-stage throttle hole is located and the central section where the second-stage throttle hole is located is 60-80 mm.

3. The ball valve core for efficiently suppressing cavitation according to claim 1, characterized in that: The distance between the central section where the first-stage throttling hole is located and the central plane of the ball valve core is 120~180mm.

4. The ball valve core for efficiently suppressing cavitation according to claim 1, characterized in that: The distance between the central section where the second-stage throttling hole is located and the central plane of the ball valve core is 200~250mm.

5. A ball valve with high efficiency in suppressing cavitation, characterized in that: The invention comprises a valve body and a ball valve core installed on the valve body, wherein the ball valve core is the cavitation-inhibiting ball valve core according to any one of claims 1 to 4.

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