A large-diameter high-temperature high-pressure subcritical once-through hot water boiler ball valve

Abstract

The application relates to a large-diameter high-temperature high-pressure subcritical direct-flow hot water boiler ball valve, and relates to the technical field of valve design, which comprises a valve body, a ball body arranged in the valve body, a first flow channel arranged in the ball body, graphite rings arranged at two ends of the ball body, and a flow channel outlet of the first flow channel facing the inner side of the graphite ring; a valve rod penetrating through the valve body and connected with the ball body, a second flow channel arranged in the valve rod and communicated with the first flow channel, and the second flow channel being used for inputting filling medium into the first flow channel and enabling the graphite ring to abut against the inner side of the valve body to seal the connecting position of the ball body and the valve body. The pressure generated by the externally input filling medium is used for driving the graphite ring to abut against the inner side of the valve body. The active pressure application mode enables the sealing specific pressure to be adjusted according to the pipeline working condition. Especially in the high-temperature high-pressure environment, when a tiny gap is generated due to thermal expansion or creep of the valve body, the ball body or the graphite ring, the filling medium pressure can be supplemented or maintained, so that the graphite ring continuously tracks and compensates the gap.

Description

Technical Field

[0001] This invention relates to the field of valve design technology, specifically to a large-diameter, high-temperature, high-pressure, subcritical once-through hot water boiler ball valve. Background Technology

[0002] Ball valves, as an important type of shut-off valve, are widely used in pipeline systems in industries such as petroleum, chemical, and nuclear power. They are primarily used for media transport control and system isolation. Especially in nuclear power main pipelines or large petrochemical pipeline systems, the pipelines often have large diameters, high temperatures, and high pressures, and extremely stringent requirements for controlling media leakage rates. Under these extreme conditions, the sealing performance of the isolation valve directly affects the safe and stable operation of the entire pipeline system.

[0003] In the prior art, ball valve sealing is generally achieved by applying an initial preload to the sealing seat during the valve assembly stage using mechanical components such as bolts, nuts, or springs, so that the sealing element fits against the valve body and the ball core surface. The sealing element is generally a rigid or semi-rigid annular piece made of graphite and installed in the sealing groove behind the valve seat, and is preloaded by springs or bolts.

[0004] However, under high temperature and high pressure conditions, the valve body, ball core, and seals will undergo thermal expansion or creep, causing changes in the original mechanical preload. Especially when the temperature fluctuates drastically, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, which can easily lead to seal failure and affect the normal use of the ball valve. Summary of the Invention

[0005] This application provides a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve, which solves the problem in existing technologies where, under high-temperature and high-pressure conditions, the valve body, ball core, and sealing components undergo thermal expansion or creep, leading to changes in the original mechanical preload. Especially during drastic temperature fluctuations, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, easily resulting in sealing failure and affecting the normal operation of the ball valve.

[0006] In a first aspect, embodiments of this application provide a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve, which includes: Valve body; A sphere is disposed within the valve body, the sphere having a first flow channel, and graphite rings at both ends of the sphere, with the outlet of the first flow channel facing the inner side of the graphite rings; A valve stem passes through the valve body and is connected to the ball. The valve stem has a second flow channel that communicates with the first flow channel. The second flow channel is used to input the filling medium into the first flow channel, so that the graphite ring abuts against the inside of the valve body to seal the connection between the ball and the valve body.

[0007] In one embodiment, both ends of the ball are provided with mounting ring grooves, and the graphite rings are provided in the mounting ring grooves. The mounting ring grooves are connected to the first flow channel. The inner diameter of the mounting ring grooves is larger than the inner diameter of the flow channels at both ends of the valve body. If the ball valve is in the closed state, the axis of the mounting ring grooves coincides with the axis of the flow channels at both ends of the valve body.

[0008] In one embodiment, a pushing component is provided within the mounting annular groove, the pushing component comprising: The top plate abuts against the inner side of the graphite ring and matches the mounting ring groove; A push rod is provided that corresponds one-to-one with the outlet of the first flow channel. The push rod is connected to the side of the top plate away from the graphite ring, and the outer diameter of the push rod matches the inner diameter of the outlet of the first flow channel.

[0009] In one embodiment, the first flow channel includes connecting flow channels spaced apart along the axial direction of the valve stem, and conveying flow channels located at both ends of the connecting flow channels. The upper connecting flow channel is connected to the second flow channel, and the upper and lower ends of the conveying flow channel are respectively connected to the two connecting flow channels.

[0010] In one embodiment, the longitudinal section of the conveying channel is a regular hexagon, and each of the six outer corners of the conveying channel is provided with a channel outlet. The upper connecting channel is connected to the midpoint of the uppermost transverse channel of the conveying channel.

[0011] In one embodiment, both ends of each side channel of the conveying channel extend to the surface of the sphere, and each extension of the side channel is provided with a plug.

[0012] In one embodiment, the ball is provided with a connecting groove, the valve stem is used to extend into the connecting groove, and is fixed relative to the connecting groove by a flat key on the outside of the valve stem.

[0013] In one embodiment, a sealing assembly is further provided between the ball and the valve stem, the sealing assembly comprising: A graphite ring gasket and a graphite ring pressure plate are spaced apart along the axial direction of the valve stem, the graphite ring gasket being located within the connecting groove, and the graphite ring pressure plate abutting against the end of the valve stem; A graphite ring is disposed between the graphite ring pad and the graphite ring pressure plate.

[0014] In one embodiment, a threaded retaining ring is further included, which is threadedly connected to the inner sidewall of the connecting groove, and the threaded retaining ring is used to abut against the upper side of the flat key.

[0015] In one embodiment, a rocker wheel is provided at the end of the valve stem away from the ball, and the inlet of the second flow channel is located at the axis of the rocker wheel.

[0016] The beneficial effects of the technical solutions provided in this application include: In designing this ball valve for high-temperature and high-pressure pipelines, the ball is housed within the valve body, which contains a first flow channel. Graphite rings are located at both ends of the ball, with the outlet of the first flow channel facing the inner side of the graphite rings. The valve stem passes through the valve body and connects to the ball. A second flow channel, communicating with the first flow channel, is located within the valve stem. This second flow channel allows the filling medium to be introduced into the first flow channel, causing the graphite rings to press against the inner side of the valve body, sealing the connection between the ball and the valve body. By establishing a second flow channel within the valve stem and a first flow channel within the ball, a pressure medium transmission channel is created from the outside to the inside of the ball. Unlike traditional passive seals that rely on springs or bolt pre-tightening, this design utilizes the pressure generated by the externally input filling medium to drive the graphite rings against the inner side of the valve body. This active pressure application method allows the sealing pressure to be adjusted according to pipeline operating conditions. Especially under high temperature and high pressure environments, when the valve body, ball, or graphite ring develops minute gaps due to thermal expansion or creep, the graphite ring can continuously track and compensate for the gaps by supplementing or maintaining the pressure of the filling medium. This solves the problem in existing technologies where the valve body, ball core, and seals undergo thermal expansion or creep under high temperature and high pressure conditions, leading to changes in the original mechanical preload. Particularly during drastic temperature fluctuations, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, easily leading to seal failure and affecting the normal operation of the ball valve. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the longitudinal section of an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve according to the present invention.

[0019] Figure 2 This is a schematic diagram of the valve stem end in an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve of the present invention.

[0020] Figure 3 This is a schematic diagram of the sealing assembly in an embodiment of a large-diameter, high-temperature, high-pressure, subcritical once-through hot water boiler ball valve of the present invention.

[0021] Figure 4 for Figure 1 A schematic diagram of the structure of section AA.

[0022] Figure 5This is a schematic diagram of the conveying flow channel in an embodiment of a large-diameter, high-temperature, high-pressure, subcritical once-through hot water boiler ball valve of the present invention.

[0023] Figure 6 This is a schematic diagram of an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve according to the present invention.

[0024] Figure 7 This is a schematic diagram of the opening of a ball valve in an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler according to the present invention.

[0025] Figure 8 This is a schematic diagram of the ball valve closing in an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler according to the present invention.

[0026] Figure 9 This is a schematic diagram of the top plate structure in an embodiment of a large-diameter, high-temperature, high-pressure, subcritical once-through hot water boiler ball valve of the present invention.

[0027] Figure 10 This is a schematic diagram of the graphite ring structure in an embodiment of a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve of the present invention.

[0028] In the diagram: 1. Valve body; 11. Left valve body; 12. Right valve body; 2. Ball; 21. First flow channel; 211. Connecting flow channel; 212. Conveying flow channel; 22. Mounting ring groove; 23. Connecting groove; 3. Graphite ring; 4. Valve stem; 41. Second flow channel; 42. Flat key; 5. Pushing assembly; 51. Top plate; 52. Push rod; 6. Plug; 7. Sealing assembly; 71. Graphite ring gasket; 72. Graphite ring pressure plate; 73. Graphite ring; 8. Threaded pressure ring; 9. Rocker wheel; 10. Sealing ring. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0030] This application provides a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve, which solves the problem in the prior art where, under high-temperature and high-pressure conditions, the valve body, ball core, and seals undergo thermal expansion or creep, causing changes in the original mechanical preload. Especially during drastic temperature fluctuations, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, easily leading to sealing failure and affecting the normal use of the ball valve.

[0031] like Figure 1 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, this application provides a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler ball valve, which includes: Valve body 1; A ball 2 is disposed inside the valve body 1. A first flow channel 21 is provided inside the ball 2. Graphite rings 3 are provided at both ends of the ball 2. The flow channel outlet of the first flow channel 21 faces the inside of the graphite rings 3. The valve stem 4 passes through the valve body 1 and is connected to the ball 2. The valve stem 4 has a second flow channel 41 that communicates with the first flow channel 21. The second flow channel 41 is used to input the filling medium into the first flow channel 21, so that the graphite ring 3 abuts against the inside of the valve body 1 to seal the connection between the ball 2 and the valve body 1.

[0032] In designing this ball valve for high-temperature and high-pressure pipelines, a ball 2 is housed within a valve body 1. A first flow channel 21 is provided within the ball 2, and graphite rings 3 are located at both ends of the ball 2. The outlet of the first flow channel 21 faces the inner side of the graphite rings 3. A valve stem 4 passes through the valve body 1 and connects to the ball 2. A second flow channel 41, communicating with the first flow channel 21, is provided within the valve stem 4. The second flow channel 41 is used to input the filling medium into the first flow channel 21, causing the graphite rings 3 to abut against the inner side of the valve body 1, thus sealing the connection between the ball 2 and the valve body 1. By providing a second flow channel 41 within the valve stem 4 and a first flow channel 21 within the ball 2, a pressure medium transmission channel from the outside to the inside of the ball 2 is constructed. Unlike traditional passive seals that rely on springs or bolt pre-tightening, this design utilizes the pressure generated by the externally input filling medium to drive the graphite rings 3 to abut against the inner side of the valve body 1. This active pressure application method allows the sealing pressure to be adjusted according to pipeline operating conditions. Especially under high temperature and high pressure environments, when the valve body 1, ball 2, or graphite ring 3 develops minute gaps due to thermal expansion or creep, the graphite ring 3 can continuously track and compensate for the gaps by supplementing or maintaining the pressure of the filling medium. This solves the problem in existing technologies where the valve body, ball core, and seals undergo thermal expansion or creep under high temperature and high pressure conditions, leading to changes in the original mechanical preload. Particularly during drastic temperature fluctuations, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, easily leading to seal failure and affecting the normal operation of the ball valve.

[0033] In this example, a sealing ring 10 is also provided between the valve stem 4 and the valve body 1. The valve body 1 includes a left valve body 11 and a right valve body 12. The valve stem 4 passes through the right valve body 12 and connects to the ball 2. The left valve body 11 and the right valve body 12 are connected by bolts. A graphite spiral wound gasket is provided between the left valve body 11 and the right valve body 12. The filling medium is a fluid medium with a pressure higher than that of the pipeline system, such as water, oil, or gas. Figure 7 and Figure 8 The green arrows indicate the flow direction of the piping system, while the red arrows indicate the flow direction of the filling medium.

[0034] like Figure 1 and Figure 4 As shown, in some optional embodiments, both ends of the ball 2 are provided with mounting annular grooves 22, and graphite rings 3 are provided in the mounting annular grooves 22. The mounting annular grooves 22 are connected to the first flow channel 21. The inner diameter of the mounting annular grooves 22 is larger than the inner diameter of the flow channels at both ends of the valve body 1. If the ball valve is in the closed state, the axis of the mounting annular grooves 22 coincides with the axis of the flow channels at both ends of the valve body 1.

[0035] In this embodiment, both ends of the ball 2 are provided with mounting annular grooves 22, and a graphite ring 3 is provided in the mounting annular grooves 22. The mounting annular grooves 22 are connected to the first flow channel 21. The inner diameter of the mounting annular grooves 22 is larger than the inner diameter of the flow channels at both ends of the valve body 1. When the ball valve is in the closed state, the axis of the mounting annular grooves 22 coincides with the axis of the flow channels at both ends of the valve body 1. By limiting the inner diameter of the mounting annular grooves 22 to be larger than the inner diameter of the flow channels at both ends of the valve body 1, it is ensured that the effective sealing area of ​​the graphite ring 3 completely covers the flow cross section of the pipeline medium. This design makes the sealing area located outside the edge of the flow channel, which not only avoids the erosion damage caused by the direct scouring of the sealing surface by high-speed fluid, but also prevents the medium from leaking from the gap between the inner edge of the graphite ring 3 and the flow channel, significantly improving the sealing reliability of the valve under high pressure conditions, and ensuring that the graphite ring 3 and the sealing surface of the valve body 1 can be precisely aligned after the ball 2 is rotated and closed. This high-precision alignment design eliminates the eccentric force caused by assembly errors or rotation angle deviations, ensuring that the graphite ring 3 is subjected to uniform force in the circumferential direction. Especially under high temperature and high pressure environments, it can effectively prevent graphite ring damage or sealing failure caused by local stress concentration, thus extending the service life of the valve.

[0036] like Figure 1 , Figure 4 and Figure 10 As shown, in some optional embodiments, a pushing component 5 is provided within the mounting ring groove 22, the pushing component 5 including: The top plate 51 abuts against the inner side of the graphite ring 3 and matches the mounting ring groove 22; The push rod 52 corresponds one-to-one with the outlet of the first flow channel 21. The push rod 52 is connected to the side of the top plate 51 away from the graphite ring 3. The outer diameter of the push rod 52 matches the inner diameter of the outlet of the first flow channel 21.

[0037] In this embodiment, a pushing assembly 5 is provided within the mounting annular groove 22. The pushing assembly 5 includes a top plate 51 and push rods 52 corresponding to the outlets of the first flow channel 21. The top plate 51 abuts against the inner side of the graphite ring 3 and matches the mounting annular groove 22. The push rods 52 are connected to the side of the top plate 51 away from the graphite ring 3, and the outer diameter of the push rods 52 matches the inner diameter of the outlet of the first flow channel 21. By setting the top plate 51 to abut against the inner side of the graphite ring 3, the high-pressure filling medium is physically isolated from the graphite ring 3. This avoids the high-pressure fluid directly impacting the surface of the graphite ring 3, preventing medium penetration, surface erosion and peeling, or structural damage caused by the porosity or brittleness of the graphite material. The top plate 51 converts the fluid pressure into a stable mechanical thrust, extending the service life of the graphite ring 3. The push rods 52 correspond one-to-one with the outlets of the first flow channel 21, providing multiple discrete thrust points, while the top plate 51 integrates these point thrusts into a uniform surface pressure acting on the back of the graphite ring 3. This structure effectively solves the problem of local stress concentration caused by uneven force distribution at a single point, ensuring that the graphite ring 3 is subjected to uniform force in the circumferential direction, and can fit more tightly to the inner sealing surface of the valve body 1, significantly reducing the risk of leakage.

[0038] like Figure 1 , Figure 4 and Figure 5 As shown, in some optional embodiments, the first flow channel 21 includes a connecting flow channel 211 spaced apart along the axial direction of the valve stem 4, and a conveying flow channel 212 located at both ends of the connecting flow channel 211. The upper connecting flow channel 211 is connected to the second flow channel 41, and the upper and lower ends of the conveying flow channel 212 are connected to the two connecting flow channels 211 respectively.

[0039] In this embodiment, the first flow channel 21 includes connecting flow channels 211 spaced apart along the axial direction of the valve stem 4, and conveying flow channels 212 located at both ends of the connecting flow channels 211. The upper connecting flow channel 211 is connected to the second flow channel 41, and the upper and lower ends of the conveying flow channel 212 are connected to the two connecting flow channels 211 respectively. Through the combined design of the connecting flow channels 211 and the conveying flow channels 212, a three-dimensional fluid distribution network is formed inside the sphere 2. The upper connecting flow channel 211 serves as the main inlet to receive the filling medium from the valve stem 4, and then the medium is conveyed to the mounting ring groove 22 through the conveying flow channels 212 at both ends. This ensures that the graphite rings 3 at both ends of the sphere 2 can simultaneously receive pressure signals and generate displacement, realizing synchronous drive of bidirectional sealing. This structure avoids the pressure attenuation problem caused by a single long flow channel, ensuring that the high-pressure medium can be quickly and with low resistance delivered to various predetermined positions inside the sphere 2, improving the response speed of the sealing action.

[0040] like Figure 1 , Figure 4 and Figure 5As shown, in some optional embodiments, the longitudinal section of the conveying channel 212 is a regular hexagon, and the six outer corners of the conveying channel 212 are provided with channel outlets. The upper connecting channel 211 is connected to the midpoint of the uppermost transverse channel of the conveying channel 212.

[0041] In this embodiment, the longitudinal section of the conveying channel 212 is a regular hexagon, and each of the six outer corners of the conveying channel 212 has a channel outlet. The upper connecting channel 211 is connected to the midpoint of the uppermost transverse channel of the conveying channel 212. The conveying channel 212 adopts a regular hexagonal longitudinal section and has channel outlets at each of the six outer corners. Utilizing the geometric symmetry of the regular hexagon, the medium is evenly distributed at six points in the circumferential direction. This design makes the fluid driving force on the pushing component more uniform, avoiding the deflection of the graphite ring 3 caused by force at a single point or a few points, ensuring that the graphite ring 3 can be parallel and tightly fitted to the inner sealing surface of the valve body 1, significantly improving the reliability of the seal. The upper connecting channel 211 is connected to the midpoint of the uppermost transverse channel of the conveying channel 212. This central inlet method ensures that after the filling medium enters the conveying channel 212, it can flow symmetrically to both sides. It effectively eliminates fluid impact imbalance and pressure gradient caused by inlet eccentricity, prevents unnecessary lateral forces from being generated inside ball 2, and ensures the valve's posture stability during the pressurization and sealing process.

[0042] like Figure 5 As shown, in some optional embodiments, both ends of each side channel of the conveying channel 212 extend to the surface of the sphere 2, and each extension of the side channel is provided with a plug 6.

[0043] In this embodiment, both ends of each side channel of the conveying channel 212 extend to the surface of the sphere 2, and each extension section of the side channel is provided with a plug 6. By extending both ends of each side channel of the complex conveying channel 212 inside the sphere 2 to the surface of the sphere, the internal channels can be directly formed from the outside using standard drilling processes, avoiding the difficulties of complex blind hole machining or casting inside a solid sphere. The plugs 6, used to seal the extension sections, ensure both the convenience and precision of channel forming and restore the integrity of the sphere 2 surface, effectively reducing the manufacturing difficulty and production cost of the sphere.

[0044] like Figure 2 As shown, in some optional embodiments, the ball 2 is provided with a connecting groove 23, the valve stem 4 is used to extend into the connecting groove 23, and is fixed relative to the connecting groove 23 by a flat key 42 on the outside of the valve stem 4.

[0045] In this embodiment, the ball 2 is provided with a connecting groove 23, into which the valve stem 4 extends and is fixed relative to the connecting groove 23 by a flat key 42 on the outside of the valve stem 4. The circumferential fixation between the valve stem 4 and the ball 2 is achieved through the cooperation of the flat key 42 and the connecting groove 23. This rigid connection effectively transmits operating torque, ensuring that the rotation of the valve stem 4 is accurately synchronized with the ball 2 when opening or closing the valve under high pressure differential conditions. This avoids problems such as incomplete valve opening or control failure due to loose connections or slippage, improving the accuracy of valve operation. The connecting groove 23 provides guidance and limitation for the extension of the valve stem 4. Combined with the keyway of the flat key 42, the relative angular position of the valve stem 4 and the ball 2 can be quickly and accurately determined. This not only simplifies the assembly process but also ensures the coaxiality of the valve stem 4 axis and the rotation axis of the ball 2, reducing vibration and eccentric wear during valve operation and extending the valve's service life.

[0046] like Figure 1 , Figure 2 and Figure 3 As shown, in some optional embodiments, a sealing assembly 7 is further provided between the ball 2 and the valve stem 4. The sealing assembly 7 includes: Graphite ring gaskets 71 and graphite ring pressure plates 72 are spaced apart along the valve stem 4. The graphite ring gaskets 71 are located in the connecting groove 23, and the graphite ring pressure plates 72 abut against the end of the valve stem 4. The graphite ring 73 is disposed between the graphite ring pad 71 and the graphite ring pressure plate 72.

[0047] In this embodiment, a sealing assembly 7 is also provided between the ball 2 and the valve stem 4. The sealing assembly 7 includes a graphite ring gasket 71 and a graphite ring pressure plate 72 spaced apart along the axial direction of the valve stem 4, and a graphite ring 73. The graphite ring gasket 71 is located in the connecting groove 23, and the graphite ring pressure plate 72 abuts against the end of the valve stem 4. The graphite ring 73 is disposed between the graphite ring gasket 71 and the graphite ring pressure plate 72. By providing a sealing assembly consisting of a gasket, a pressure plate, and a graphite ring between the ball 2 and the valve stem 4, a reliable static sealing structure is formed. This structure effectively blocks the path of leakage of the filling medium along the connection gap between the valve stem 4 and the ball 2. Especially under the action of high-pressure filling medium, it ensures the sealing isolation between the driving end of the valve stem 4 and the internal cavity of the ball 2, and improves the overall sealing safety of the valve. Furthermore, the use of a sandwich structure of "gasket-graphite ring-pressure plate" utilizes the graphite ring gasket 71 and the graphite ring pressure plate 72 as support members to evenly transmit the assembly preload to the middle graphite ring 73. This design avoids the risk of localized stress concentration, edge extrusion, or breakage caused by direct compression of the graphite ring 73 by metal components, effectively protecting the integrity of the graphite seal and extending the service life of the sealing assembly.

[0048] like Figure 1 and Figure 2As shown, in some optional embodiments, a threaded retaining ring 8 is also included, which is threadedly connected to the inner wall of the connecting groove 23 and is used to abut against the upper side of the flat key 42.

[0049] In this embodiment, the ball valve for high-temperature and high-pressure pipelines also includes a threaded pressure ring 8, which is threadedly connected to the inner wall of the connecting groove 23. The threaded pressure ring 8 is used to abut against the upper side of the flat key 42. The threaded pressure ring 8 abuts against the upper side of the flat key 42, forming an axial locking structure for the flat key 42. This effectively prevents the flat key 42 from axially moving or even falling out of the connecting groove 23 under long-term vibration, impact, or alternating load conditions, avoiding the risk of connection failure between the valve stem 4 and the ball 2 due to key failure, and significantly improving the safety and reliability of the transmission structure.

[0050] like Figure 1 and Figure 6 As shown, in some optional embodiments, the valve stem 4 is provided with a rocker wheel 9 at the end away from the ball 2, and the inlet of the second flow channel 41 is located at the axis of the rocker wheel 9.

[0051] In this embodiment, a rocker wheel 9 is provided at the end of the valve stem 4 away from the ball 2, and the inlet of the second flow channel 41 is located at the axis of the rocker wheel 9. Integrating the inlet of the second flow channel 41 at the axis of the rocker wheel 9 achieves a coaxial layout of the valve operating mechanism and the sealing medium input channel. This eliminates the need for additional hydraulic interfaces and external pipelines on the side of the valve body 1 or at non-axial positions of the valve stem 4, significantly simplifying the external structure of the valve, reducing space occupation, and facilitating installation in compact piping systems.

[0052] In summary, when designing this ball valve for high-temperature and high-pressure pipelines, the ball 2 is disposed within the valve body 1, and a first flow channel 21 is provided within the ball 2. Graphite rings 3 are provided at both ends of the ball 2, with the outlet of the first flow channel 21 facing the inner side of the graphite rings 3. The valve stem 4 passes through the valve body 1 and connects to the ball 2. A second flow channel 41, communicating with the first flow channel 21, is provided within the valve stem 4. The second flow channel 41 is used to input the filling medium into the first flow channel 21, causing the graphite rings 3 to abut against the inner side of the valve body 1, thereby sealing the connection between the ball 2 and the valve body 1. By providing a second flow channel 41 within the valve stem 4 and a first flow channel 21 within the ball 2, a pressure medium transmission channel from the outside to the inside of the ball 2 is constructed. Unlike traditional passive seals that rely on springs or bolt pre-tightening, this solution utilizes the pressure generated by the externally input filling medium to drive the graphite rings 3 to abut against the inner side of the valve body 1. This active pressure application method allows the sealing pressure to be adjusted according to the pipeline operating conditions. Especially under high temperature and high pressure environments, when the valve body 1, ball 2, or graphite ring 3 develops minute gaps due to thermal expansion or creep, the graphite ring 3 can continuously track and compensate for the gaps by supplementing or maintaining the pressure of the filling medium. This solves the problem in existing technologies where the valve body, ball core, and seals undergo thermal expansion or creep under high temperature and high pressure conditions, leading to changes in the original mechanical preload. Particularly during drastic temperature fluctuations, the static mechanical preload cannot dynamically compensate for the gaps caused by thermal deformation, easily leading to seal failure and affecting the normal operation of the ball valve.

[0053] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, 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 communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0054] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0055] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler, characterized in that: include: Valve body (1); A sphere (2) is disposed inside the valve body (1). A first flow channel (21) is provided inside the sphere (2). Graphite rings (3) are provided at both ends of the sphere (2). The flow channel outlet of the first flow channel (21) faces the inside of the graphite ring (3). A valve stem (4) passes through the valve body (1) and is connected to the ball (2). The valve stem (4) has a second flow channel (41) that communicates with the first flow channel (21). The second flow channel (41) is used to input the filling medium into the first flow channel (21) so that the graphite ring (3) abuts against the inside of the valve body (1) to seal the connection between the ball (2) and the valve body (1).

2. The ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler as described in claim 1, characterized in that, The ball (2) has mounting ring grooves (22) at both ends, and the graphite ring (3) is provided in the mounting ring grooves (22). The mounting ring grooves (22) are connected to the first flow channel (21). The inner diameter of the mounting ring grooves (22) is larger than the inner diameter of the flow channels at both ends of the valve body (1). If the ball valve is in the closed state, the axis of the mounting ring grooves (22) coincides with the axis of the flow channels at both ends of the valve body (1).

3. The ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler as described in claim 2, characterized in that, The mounting ring groove (22) is provided with a pushing component (5), the pushing component (5) including: The top plate (51) abuts against the inner side of the graphite ring (3) and matches the mounting ring groove (22); A push rod (52) is corresponding to the outlet of the first flow channel (21). The push rod (52) is connected to the side of the top plate (51) away from the graphite ring (3). The outer diameter of the push rod (52) matches the inner diameter of the outlet of the first flow channel (21).

4. The ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler as described in claim 1, characterized in that, The first flow channel (21) includes a connecting flow channel (211) spaced apart along the axial direction of the valve stem (4), and a conveying flow channel (212) located at both ends of the connecting flow channel (211). The upper connecting flow channel (211) is connected to the second flow channel (41), and the upper and lower ends of the conveying flow channel (212) are respectively connected to the two connecting flow channels (211).

5. A large-diameter high-temperature and high-pressure subcritical once-through hot water boiler ball valve as described in claim 4, characterized in that, The longitudinal section of the conveying channel (212) is a regular hexagon. The six outer corners of the conveying channel (212) are provided with channel outlets. The upper connecting channel (211) is connected to the midpoint of the uppermost transverse channel of the conveying channel (212).

6. The ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler as described in claim 5, characterized in that, The two ends of each side channel of the conveying channel (212) extend to the surface of the sphere (2), and each side channel extension is provided with a plug (6).

7. The ball valve for a large-diameter, high-temperature, high-pressure subcritical once-through hot water boiler as described in claim 1, characterized in that, The ball (2) is provided with a connecting groove (23), and the valve stem (4) is used to extend into the connecting groove (23) and is fixed relative to the connecting groove (23) by a flat key (42) on the outside of the valve stem (4).

8. A large-diameter high-temperature and high-pressure subcritical once-through hot water boiler ball valve as described in claim 7, characterized in that, A sealing assembly (7) is also provided between the ball (2) and the valve stem (4), the sealing assembly (7) comprising: A graphite ring gasket (71) and a graphite ring pressure plate (72) are spaced apart along the axial direction of the valve stem (4). The graphite ring gasket (71) is located in the connecting groove (23), and the graphite ring pressure plate (72) abuts against the end of the valve stem (4). A graphite ring (73) is disposed between the graphite ring pad (71) and the graphite ring pressure plate (72).

9. A large-diameter high-temperature and high-pressure subcritical once-through hot water boiler ball valve as described in claim 7, characterized in that, It also includes a threaded pressure ring (8), which is threadedly connected to the inner wall of the connecting groove (23) and is used to abut against the upper side of the flat key (42).

10. A large-diameter high-temperature and high-pressure subcritical once-through hot water boiler ball valve as described in claim 1, characterized in that, The valve stem (4) is provided with a rocker wheel (9) at one end away from the ball (2), and the inlet of the second flow channel (41) is located at the axis of the rocker wheel (9).

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