Self-compensating sealing structure of water turbine inlet ball valve

Abstract

This invention discloses a self-compensating sealing structure for a turbine inlet ball valve, relating to the field of valve technology. The self-compensating sealing structure includes a valve body, a ball, a valve stem, and a hydraulic rod. The valve body has two openings; each opening forms a valve cavity; a ball is rotatably connected within the valve cavity; the valve stem is rotatably connected to the valve body; the ball is fixedly connected to the valve stem; the valve stem is movably connected to the extension portion of the hydraulic rod; a connecting cavity is formed within the ball; the connecting cavity is connected to a connecting hole; the connecting cavity is connected to the valve cavity; and a positive pressure pipe is connected to the valve body. This invention, by creating a connecting hole on the ball, actively introduces water into the valve body, and then introduces the pressure of the water into the hydraulic cavity. When the pressure inside the valve increases, the clamping force on the sealing ring increases synchronously, achieving real-time, adaptive compensation of the sealing force to the working pressure. This fundamentally solves the leakage risk caused by pressure fluctuations or sealing ring loosening, improves sealing reliability, and extends the life of the sealing components.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a self-compensating sealing structure for a water turbine inlet ball valve. Background Technology

[0002] In hydropower stations and hydroelectric power generation systems, the turbine inlet ball valve is a key control device. Its core function is to conduct or cut off high-pressure water flow and to provide safety protection for turbine operation. The valve is under harsh conditions of high water pressure, high flow velocity and periodic opening and closing for a long time. The reliability of its sealing performance is directly related to the operating efficiency and safety of the power station. If leakage occurs, it will not only cause energy loss, but may also cause serious accidents such as equipment erosion and plant flooding.

[0003] Currently, large-diameter high-pressure ball valves of this type generally use elastic sealing rings (such as rubber or polyurethane materials) and metal balls to form a sealing pair. Common sealing designs rely on preload to achieve initial sealing, that is, applying axial pressure to the sealing ring through a mechanical gland or bolt group, causing it to elastically deform and fit tightly against the ball surface. However, this traditional method has inherent defects: First, the sealing ring will experience stress relaxation and aging under long-term pressure and fluid immersion, resulting in a gradual decrease in preload; Second, in actual operation, the upstream water pressure is not constant and will fluctuate drastically due to changes in power grid load, water hammer effect, etc. The fixed mechanical preload cannot be dynamically adjusted with the rise and fall of system pressure. When the working pressure is lower than the threshold corresponding to the design preload, leakage may occur due to insufficient compression; when the working pressure rises abnormally, the fixed preload may be insufficient to ensure the safety margin of the sealing specific pressure, which also increases the risk of leakage. In addition, frequent pressure fluctuations will accelerate the fatigue damage of the sealing ring.

[0004] Existing technologies address the mismatch between preload decay and pressure fluctuation by periodically compensating with hydraulic or bolt-based methods. However, these methods are mostly passive or intermittent adjustments, failing to achieve real-time, continuous, and adaptive tracking of sealing force against working pressure. Furthermore, they are cumbersome to operate, increasing maintenance costs and downtime risks.

[0005] In the field of turbine inlet ball valves, sealing reliability is the key to ensuring the safe and stable operation of the system. Traditional mechanical pre-tightening sealing structures rely on a fixed initial clamping force, which is difficult to adapt to pressure fluctuations in actual working conditions and stress relaxation of the sealing ring after long-term use, thus posing a risk of leakage.

[0006] To improve sealing adaptability, Chinese patent CN207715810U discloses a self-tightening sealing ball valve that uses medium pressure to push the valve seat to achieve compensation. However, the synchronicity and directness of its compensation effect are insufficient, and the structure has a delay in responding to pressure transients.

[0007] Chinese patent CN216009613U discloses a valve seat preload compensation structure for a regulating ball valve, which uses an external adjustment mechanism for compensation. This method is essentially a passive intermittent adjustment and cannot achieve continuous self-adaptation of the sealing force to the internal pressure.

[0008] In summary, none of the existing improvement solutions have been able to fundamentally achieve real-time, linear, and adaptive dynamic matching of sealing force to working pressure. They still have limitations in dealing with frequent pressure fluctuations and long-term operational reliability. Furthermore, self-tightening structures often have insufficient sealing pressure during low-pressure startup, while external mechanical compensation methods cannot achieve real-time and continuous adaptive matching of sealing force to system pressure. Summary of the Invention

[0009] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0010] In view of the problems existing in the above and / or existing self-tightening sealing ball valves, the present invention is proposed.

[0011] Therefore, the problem to be solved by the present invention is how to overcome the shortcomings of existing mechanical seal compensation methods that cannot achieve real-time and continuous adaptive matching of sealing force to system pressure. The present invention provides a self-compensating sealing structure for a water turbine inlet ball valve.

[0012] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a self-compensating sealing structure for a turbine inlet ball valve, comprising a valve body, a ball, a valve stem, and a hydraulic rod; the valve body has two openings; the two openings of the valve body form valve chambers; a ball is rotatably connected within the valve chambers; it also includes a positive pressure pipe, a first branch pipe, an annular pipe, a diverter pipe, an elastic element, and a sealing ring; a communicating cavity is formed within the ball; the communicating cavity is connected to a communicating hole; the communicating cavity is connected to the valve chamber; the valve body is connected to the positive pressure pipe; the positive pressure pipe is connected to the first branch pipe; the first branch pipe is connected to the annular pipe; the annular pipe is sleeved outside the valve body; the annular pipe is connected to the diverter pipe; a hydraulic chamber is formed on the valve body; the hydraulic chamber is connected to the valve chamber; the diverter pipe is connected to the hydraulic chamber; an elastic element is fixedly connected within the hydraulic chamber; a sealing ring is slidably connected to the hydraulic chamber; the sealing ring is fixedly connected to the elastic element; the sealing ring is in contact with the ball.

[0013] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve described in this invention, a filter screen is provided on the side of the connecting hole away from the connecting cavity.

[0014] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve of the present invention, it further includes: a floating plate, a first spring rod, and a sealing ring; the floating plate is slidably connected inside the positive pressure pipe; the floating plate is fixedly connected to the first spring rod; the first spring rod consists of a vertical rod and a spring; the spring of the first spring rod is fixedly connected to the positive pressure pipe; the vertical rod of the first spring rod is fixedly connected to the sealing ring; the sealing ring is slidably connected to the positive pressure pipe; and the sealing ring is in contact with the first branch pipe.

[0015] As a preferred embodiment of the self-compensating sealing structure of the water turbine inlet ball valve described in this invention, the floating plate is made of rubber material coated with a lubricating coating.

[0016] As a preferred embodiment of the self-compensating sealing structure of the water turbine inlet ball valve described in this invention, a light indicator is provided on the vertical rod of the first spring rod.

[0017] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve described in this invention, the sealing ring is made of rubber with a wear-resistant coating on its outer surface.

[0018] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve of the present invention, it further includes: a second spring rod and a constriction ring; the second spring rod is fixedly connected in the connecting hole; the second spring rod is composed of a crossbar, a conical head and a spring; the constriction ring is fixedly connected in the connecting hole; each constriction ring contacts the conical head of a second spring rod.

[0019] In a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve described in this invention, the conical head on the second spring rod is made of rubber.

[0020] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve described in this invention, the flow channel of the constriction ring cross-section is dumbbell-shaped.

[0021] As a preferred embodiment of the self-compensating sealing structure of the turbine inlet ball valve of the present invention, it further includes: a negative pressure pipe, a second branch pipe, an electric push rod, a connecting rod, and a piston; the valve body is connected to the negative pressure pipe; the negative pressure pipe is connected to the second branch pipe; the second branch pipe is connected to the hydraulic chamber; the valve body is equipped with an electric push rod; the telescopic part of the electric push rod is fixedly connected to the connecting rod; the connecting rod is fixedly connected to the piston; the piston is composed of a support rod and a sealing plate; the piston is slidably connected to the negative pressure pipe.

[0022] The beneficial effects of this invention are as follows: 1. By opening a connecting hole on the ball, water is actively introduced into the valve body, and then the pressure of the water is introduced into the hydraulic chamber. When the pressure inside the valve increases, the clamping force obtained by the sealing ring increases synchronously, realizing real-time and adaptive compensation of the sealing force to the working pressure. This fundamentally solves the leakage risk caused by pressure fluctuations or loosening of the sealing ring, improves the sealing reliability and extends the service life of the sealing components.

[0023] 2. By setting a floating plate, when the pressure suddenly increases, the floating plate will move upward and the light indicator on the vertical rod of the first spring rod will light up, which is convenient for monitoring the pressure change in the pipeline. In addition, the first branch pipe is sealed by the sealing ring to prevent the sealing ring from being excessively pressed on the ball due to the sudden increase in pressure, thus preventing the ball from rotating.

[0024] 3. By actively extracting water from the hydraulic chamber, impurities in the hydraulic chamber can be carried away, achieving dynamic cleaning of the hydraulic chamber. Then, when the negative pressure pipe squeezes the water out again, the impurities also enter the valve chamber with the squeezed water, thereby reducing the accumulation of impurities in the hydraulic chamber and improving the sealing performance and maintenance convenience of the ball valve under complex working conditions. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a three-dimensional structural diagram of the self-compensating sealing structure of the turbine inlet ball valve of the present invention.

[0027] Figure 2 This is a first-view side view of the self-compensating sealing structure of the turbine inlet ball valve of the present invention;

[0028] Figure 3 This is a second side view of the self-compensating sealing structure of the turbine inlet ball valve of the present invention;

[0029] Figure 4 This is a schematic diagram of the internal structure of the valve body of the present invention;

[0030] Figure 5 This is a schematic diagram of the internal structure of the positive pressure tube of the present invention;

[0031] Figure 6 This is a schematic diagram of the internal structure of the connecting hole in this invention;

[0032] Figure 7This is a schematic diagram of the installation position of the negative pressure pipe of the present invention;

[0033] Figure 8 This is a schematic diagram of the internal structure of the negative pressure tube of the present invention.

[0034] The meanings of the reference numerals in the figure are as follows: 1-valve body, 2-ball, 3-valve stem, 4-hydraulic rod, 5-positive pressure pipe, 6-first branch pipe, 7-ring pipe, 8-diverter pipe, 9-elastic element, 10-sealing ring, 11-floating plate, 12-first spring rod, 13-sealing ring, 14-second spring rod, 15-contraction ring, 16-negative pressure pipe, 17-second branch pipe, 18-electric push rod, 19-connecting rod, 20-piston, 101-valve cavity, 102-hydraulic cavity, 201-connecting hole, 202-connecting cavity. Detailed Implementation

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0038] Example 1: Refer to Figure 1-6 This is the first embodiment of the present invention, which provides a self-compensating sealing structure for a turbine inlet ball valve. The self-compensating sealing structure for a turbine inlet ball valve includes a valve body 1, a ball 2, a valve stem 3, and a hydraulic rod 4. The valve body 1 has two openings. The two openings of the valve body 1 form a valve cavity 101. The ball 2 is rotatably connected inside the valve cavity 101. The valve body 1 is rotatably connected to two symmetrically distributed valve stems 3. The ball 2 is fixedly connected to all the valve stems 3. Each valve stem 3 is hinged to a telescopic part of a hydraulic rod 4. The fixed part of the hydraulic rod 4 is provided with a rotating joint to facilitate fixing the position of the hydraulic rod 4.

[0039] Specifically, it also includes a positive pressure pipe 5, a first branch pipe 6, an annular pipe 7, a diverter pipe 8, an elastic element 9, and a sealing ring 10; a connecting cavity 202 is opened inside the ball 2; a connecting hole 201 is connected to each side of the connecting cavity 202; the connecting cavity 202 is connected to the valve cavity 101; a positive pressure pipe 5 is connected to the upper part of the valve body 1; the positive pressure pipe 5 is connected to two symmetrically distributed first branch pipes 6; each first branch pipe 6 is connected to an annular pipe 7; all the annular pipes 7 are sleeved on the outside of the valve body 1; the annular pipes 7 are connected to several The valve body 1 has two symmetrically distributed hydraulic chambers 102 on its valve body 1. All hydraulic chambers 102 are connected to the valve chamber 101. All the flow dividers 8 are connected to the hydraulic chambers 102. Each hydraulic chamber 102 has several elastic elements 9 fixedly connected in a ring array. Each elastic element 9 is a spring. Each hydraulic chamber 102 is slidably connected to a sealing ring 10. Each sealing ring 10 is fixedly connected to the adjacent elastic element 9. All sealing rings 10 are in contact with the ball 2.

[0040] Specifically, a filter screen is provided on the side of the connecting hole 201 away from the connecting cavity 202.

[0041] Specifically, it also includes a floating plate 11, a first spring rod 12, and a sealing ring 13; the floating plate 11 is slidably connected inside the positive pressure pipe 5; the floating plate 11 is fixedly connected to the first spring rod 12; the first spring rod 12 consists of a vertical rod and a spring; the spring of the first spring rod 12 is fixedly connected to the top of the positive pressure pipe 5; the lower part of the vertical rod of the first spring rod 12 is fixedly connected to the sealing ring 13; the sealing ring 13 is slidably connected to the inner wall of the positive pressure pipe 5; the sealing ring 13 is in contact with all the first branch pipes 6.

[0042] Specifically, the floating piece 11 is made of rubber material coated with a lubricating coating.

[0043] Specifically, a light indicator is provided on the vertical rod of the first spring rod 12.

[0044] Specifically, the sealing ring 13 is made of rubber with a wear-resistant coating on its outer surface.

[0045] Specifically, it also includes a second spring rod 14 and a constriction ring 15; each connecting hole 201 has a second spring rod 14 fixedly connected to it; the second spring rod 14 consists of a crossbar, a conical head and a spring; each connecting hole 201 has a constriction ring 15 fixedly connected to it; each constriction ring 15 contacts the conical head of a second spring rod 14.

[0046] Specifically, the tapered head on the second spring rod 14 is made of rubber.

[0047] Specifically, the flow channel of the constriction ring 15 has a dumbbell shape in cross-section.

[0048] The working steps of the above embodiments are as follows:

[0049] In use, one end of valve body 1 is connected to the turbine inlet, and the other end is connected to the high-pressure pipeline. When in the open state, the two openings of valve body 1 are on the same straight line as the connecting cavity 202, allowing water to flow smoothly. To close the ball valve, the two hydraulic rods 4 are retracted, synchronously rotating the corresponding valve rods 3, causing the ball 2 to rotate within the valve cavity 101. After the valve cavity 101 rotates 90°, the connecting cavity 202 is perpendicular to the water flow direction, preventing water from passing through the ball valve. This achieves on / off control of the water flow. However, valve body 1 must rotate relative to the ball 2. There must be a gap between the two balls 2. In the existing technology, during the process of using a ball valve to control the flow of water, the gap between the valve body 1 and the ball 2 will gradually widen due to wear. Since the ball valve itself is a part that controls the flow of water, internal leakage may occur. Therefore, a sealing ring is usually installed between the valve body 1 and the ball 2 to ensure that there is no leakage. However, the ball 2 will also wear the sealing ring during rotation. The existing sealing structure lacks self-adaptation. Therefore, during use, the ball valve needs to be inspected regularly, and the sealing ring needs to be tightened or replaced according to the degree of wear, which wastes a lot of time and manpower.

[0050] When the ball valve is closed, water still stagnates at the end of the valve body 1 connected to the high-pressure pipeline due to the connecting hole 201 on the ball 2. Therefore, the water pressure pushes open the second spring rod 14, compressing the spring on the second spring rod 14. The conical head on the second spring rod 14 separates from the constriction ring 15, allowing water in the high-pressure pipeline to enter the connecting hole 201 through the gap between the constriction ring 15 and the conical head on the second spring rod 14. Then, water enters the connecting cavity 202 and the valve cavity 101. When the connecting cavity 202 and the valve cavity 101 are filled with water, the water enters the upper positive pressure pipe 5. Then, the water is diverted along the two first branch pipes 6, entering the annular pipe 7, and then through each branch pipe 8 into the hydraulic cavity 102. As the water level in hydraulic chamber 102 increases, the pressure within 102 increases, applying uniform pressure to the sealing ring 10 and squeezing it to one side of the ball 2. All elastic elements 9 are stretched, and the rubber sealing ring 10 is forced between the valve body 1 and the ball 2, thus achieving a seal on the ball valve. Even if the sealing ring 10 wears, the water pressure can still force it to remain between the valve body 1 and the ball 2, providing compensatory sealing for the ball valve. Furthermore, as the water pressure increases, the water pressure entering hydraulic chamber 102 also increases, resulting in a better fixation effect of the sealing ring 10 between the valve body 1 and the ball 2. This prevents a sudden increase in water pressure from causing the ball 2 to shift, affecting the smooth rotation between the ball 2 and the valve body 1, and even impacting the efficiency of water flow control.

[0051] As water enters the hydraulic chamber 102 through the positive pressure pipe 5, the sealing ring 10 adaptively compensates for the gap between the valve body 1 and the ball 2, completing the seal between the valve body 1 and the ball 2. If the water pressure in the pipeline suddenly increases, the sealing ring 10 will be excessively pressed against the ball 2, affecting the rotation of the ball 2 and consequently affecting the water flow. Therefore, an emergency switch is needed, such as by installing a floating plate 11 inside the positive pressure pipe 5. When the ball valve is just closed, water will enter the hydraulic chamber 102 through the positive pressure pipe 5, completing the seal between the valve body 1 and the ball 2. At this time, the sealing ring 10 is already pressed against the ball. When contact is made, the hydraulic chamber 102 can no longer hold more water. If the water pressure suddenly increases, the water pressure will push the floating plate 11 upward, simultaneously driving the first spring rod 12 and the sealing ring 13 to move together. The spring on the first spring rod 12 is stretched, the sealing ring 13 moves upward, and blocks the two first branch pipes 6. Thus, even if the water pressure increases, the water pressure cannot affect the sealing ring 10 in the hydraulic chamber 102, and will not cause the sealing ring 10 to be over-tightened, thereby affecting the rotation of the ball 2. This solves the risk of leakage caused by the sudden drop in water pressure and the loosening of the sealing ring 10, improves the sealing reliability and extends the service life of the seal.

[0052] When the ball valve is opened, the pressure in the connecting cavity 202 decreases, the spring on the first spring rod 12 contracts, causing the floating plate 11 and the sealing ring 13 to reset.

[0053] Based on the above working steps, we can see that the present invention also has the following effects:

[0054] By setting the diameter of the connecting cavity 202 to be the same as the diameter of the openings at both ends of the valve body 1, the ball 2 will not obstruct the water flow in the high-pressure pipeline when the water flows through this ball valve.

[0055] By symmetrically opening the connecting holes 201 on the ball body 2, the ball valve can be adapted to different installation directions without affecting its normal operation.

[0056] By setting a constriction ring 15 with a dumbbell-shaped flow channel, not only can the water pressure be more concentrated, pushing open the second spring rod 14 to facilitate water entering the connecting hole 201, but also, after rotating the ball 2, when the connecting hole 201 is perpendicular to the direction of water flow, the ball valve is in the open state, and the water flows smoothly through the ball valve. The second spring rod 14 is pressed against the constriction ring 15, thereby blocking the connecting hole 201 and effectively preventing water from entering the gap between the valve body 1 and the ball 2 through the gap between the conical head on the second spring rod 14 and the constriction ring 15.

[0057] By installing a filter screen on the connecting hole 201, it is effectively prevented that water in the high-pressure pipeline will bring mud and sand impurities into the connecting cavity 202 when the ball valve is closed. This would prevent mud and sand impurities from existing in the gap between the valve body 1 and the ball 2, increasing the wear of the valve body 1 and the ball 2, and reducing the service life of the ball valve.

[0058] By installing a floating plate 11 inside the positive pressure pipe 5, if the pressure inside the pipe suddenly increases, the upward movement of the floating plate 11 can buffer the pressure, and then the damping effect of the first spring rod 12 will absorb the pressure, effectively preventing sudden pressure changes that could lead to pipe rupture.

[0059] When the sealing ring 13 is reset, the sealing ring 13 no longer blocks the first branch pipe 6. If the ball 2 touches the sealing ring 10 during rotation, the sealing ring 10 can also discharge the hydraulic chamber 102 into the positive pressure pipe 5, thereby avoiding the situation where the sealing ring 10 hinders the rotation of the ball 2.

[0060] When the pressure in valve body 1 changes suddenly, the floating plate 11 moves, which in turn causes the light indicator on the vertical rod of the first spring rod 12 to light up. This allows for a direct indication that the ball valve has entered the pressure compensation state, facilitating the monitoring of pressure changes in the pipeline.

[0061] Example 2: Refer to Figure 1-4 , Figure 7 and Figure 8 This is the second embodiment of the present invention, which is based on the previous embodiment.

[0062] Specifically, it also includes a negative pressure pipe 16, a second branch pipe 17, an electric push rod 18, a connecting rod 19, and a piston 20; the lower part of the valve body 1 is connected to the negative pressure pipe 16; the negative pressure pipe 16 is connected to two symmetrically distributed second branch pipes 17; each second branch pipe 17 is connected to a hydraulic chamber 102; two symmetrically distributed electric push rods 18 are installed at the lower part of the valve body 1; all the telescopic parts of the electric push rods 18 are fixedly connected to the connecting rod 19; the connecting rod 19 is fixedly connected to the piston 20; the piston 20 is composed of a support rod and a sealing plate; the piston 20 is slidably connected to the negative pressure pipe 16.

[0063] The working steps of the above embodiments are as follows:

[0064] Having already achieved self-adaptive sealing of the ball valve using water pressure, if the ball valve is reopened, the sealing ring 10, which was tightly pressed against the ball 2 when the valve was closed, will still rub against the ball 2 even when the valve is opened and the water pressure no longer compresses it. This causes wear on the sealing ring 10, which is the reason for wear on the sealing ring 10 in general ball valves during actual use. Therefore, a negative pressure pipe 16 can be added to the lower part of the valve body 1. When the ball valve needs to be opened, the two electric push rods 18 can be extended, synchronously driving the connecting rod 19 and piston 20 downwards. The space above the sealing plate of the piston 20 in the negative pressure pipe 16 increases, creating negative pressure in the upper part of the negative pressure pipe 16. The negative pressure pipe 16 then extracts water from the hydraulic chamber 102 through the second branch pipe 17, causing all the elastic elements 9 to contract, synchronously driving the corresponding sealing rings 10 away from the ball. The ball 2 moves to one side, thereby allowing the sealing ring 10 to avoid the ball 2. The sealing ring 10 will not affect the rotation of the ball 2. When the ball valve is to be closed, after the ball valve is closed, the two electric push rods 18 are controlled to retract, driving the connecting rod 19 and the piston 20 to move upward, squeezing the water that has entered the negative pressure pipe 16 back into the hydraulic chamber 102. The hydraulic chamber 102 is connected to the positive pressure pipe 5 and the valve chamber 101 at this time, so the excess water will enter the positive pressure pipe 5 and will not push the sealing ring 10. Thus, by actively extracting the water in the hydraulic chamber 102, the impurities in the hydraulic chamber 102 can be carried away, achieving dynamic cleaning of the hydraulic chamber 102. Then, when the negative pressure pipe 16 squeezes the water out again, the impurities also enter the valve chamber 101 with the squeezed water, thereby reducing the accumulation of impurities in the hydraulic chamber 102 and improving the sealing performance and maintenance convenience of the ball valve under complex working conditions.

[0065] Based on the above working steps, we can see that the present invention has the following effects:

[0066] By drawing water out of the hydraulic chamber 102 through the negative pressure pipe 16, the sealing ring 10 can be moved away from the ball 2, which can effectively prevent the ball 2 from wearing the sealing ring 10 during rotation, reduce the frequency of maintenance of the ball valve, and improve the working efficiency of the water turbine.

[0067] By controlling the extension of the electric push rod 18, the amount of water drawn from the hydraulic chamber 102 can be controlled, thereby controlling the separation of the sealing ring 10 from the ball 2. This causes the sealing ring 10 to wear in contact when the ball 2 rotates, reducing the replacement frequency of the sealing ring 10, extending the service life of the sealing ring 10, and reducing the frequency of inspection and maintenance of the ball valve during use, thus improving the working efficiency of the water turbine.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A self-compensating sealing structure for a water turbine inlet ball valve, characterized in that, The device includes a valve body (1), a ball (2), a valve stem (3), and a hydraulic rod (4); the valve body (1) has two openings; the two openings of the valve body (1) form valve chambers (101); the ball (2) is rotatably connected inside the valve chambers (101); the valve body (1) is rotatably connected to the valve stem (3); the ball (2) is fixedly connected to the valve stem (3); the valve stem (3) is movably connected to the telescopic part of the hydraulic rod (4); it also includes a positive pressure pipe (5), a first branch pipe (6), an annular pipe (7), a diverter pipe (8), an elastic element (9), and a sealing ring (10); the ball (2) has a communicating cavity (202); the communicating cavity (202) is connected to a communicating hole (201); the communicating cavity (202) The valve body (1) is connected to the valve cavity (101); the valve body (1) is connected to the positive pressure pipe (5); the positive pressure pipe (5) is connected to the first branch pipe (6); the first branch pipe (6) is connected to the annular pipe (7); the annular pipe (7) is sleeved outside the valve body (1); the annular pipe (7) is connected to the diverter pipe (8); the valve body (1) has a hydraulic cavity (102); the hydraulic cavity (102) is connected to the valve cavity (101); the diverter pipe (8) is connected to the hydraulic cavity (102); an elastic element (9) is fixedly connected inside the hydraulic cavity (102); a sealing ring (10) is slidably connected to the hydraulic cavity (102); the sealing ring (10) is fixedly connected to the elastic element (9); the sealing ring (10) is in contact with the ball (2); It also includes a floating plate (11), a first spring rod (12), and a sealing ring (13); the floating plate (11) is slidably connected inside the positive pressure pipe (5); the floating plate (11) is fixedly connected to the first spring rod (12); the first spring rod (12) consists of a vertical rod and a spring; the spring of the first spring rod (12) is fixedly connected to the positive pressure pipe (5); the vertical rod of the first spring rod (12) is fixedly connected to the sealing ring (13); the sealing ring (13) is slidably connected to the positive pressure pipe (5); the sealing ring (13) is in contact with the first branch pipe (6).

2. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 1, characterized in that: A filter screen is provided on the side of the connecting hole (201) away from the connecting cavity (202).

3. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 1, characterized in that: The floating sheet (11) is made of rubber material coated with a lubricating coating.

4. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 1, characterized in that: A light indicator is provided on the vertical rod of the first spring rod (12).

5. The self-compensating sealing structure of a water turbine inlet ball valve as described in claim 1, characterized in that: The sealing ring (13) is made of rubber with a wear-resistant coating on its outer surface.

6. A self-compensating sealing structure for a turbine inlet ball valve as described in any one of claims 1-5, characterized in that: It also includes a second spring rod (14) and a constriction ring (15); the second spring rod (14) is fixedly connected in the connecting hole (201); the second spring rod (14) is composed of a crossbar, a conical head and a spring; the constriction ring (15) is fixedly connected in the connecting hole (201); each constriction ring (15) is in contact with the conical head of a second spring rod (14).

7. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 6, characterized in that: The conical head on the second spring rod (14) is made of rubber.

8. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 6, characterized in that: The flow channel of the constriction ring (15) has a dumbbell shape in cross-section.

9. The self-compensating sealing structure for a turbine inlet ball valve as described in claim 6, characterized in that: It also includes a negative pressure pipe (16), a second branch pipe (17), an electric push rod (18), a connecting rod (19), and a piston (20); the valve body (1) is connected to the negative pressure pipe (16); the negative pressure pipe (16) is connected to the second branch pipe (17); the second branch pipe (17) is connected to the hydraulic chamber (102); the valve body (1) is equipped with an electric push rod (18); the extension part of the electric push rod (18) is fixedly connected to the connecting rod (19); the connecting rod (19) is fixedly connected to the piston (20); the piston (20) is composed of a support rod and a sealing plate; the piston (20) is slidably connected to the negative pressure pipe (16).

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