Split type ball valve with internal circulation type pressure balance structure

Abstract

The invention relates to the technical field of ball valves, and discloses a split type ball valve with an internal circulation type pressure balance structure, which comprises a split type valve body, a valve ball, a valve seat and a closed middle cavity formed between the valve ball and the split type valve body, and further comprises an internal circulation pressure relief channel arranged on a solid wall of the valve ball and communicated with the middle cavity and a valve ball runner; the pressure difference pressure relief assembly is arranged in the internal circulation pressure relief channel, is automatically started when the pressure of the middle cavity exceeds a safety threshold value, and generates a sound wave signal of a specific frequency band; the monitoring unit is arranged on the outer wall face of the split type valve body and used for capturing hydrodynamic noise of a preset frequency band generated when the pressure difference pressure relief assembly is started and recognizing the pressure state of the middle cavity based on the noise. The pressure relief mode that a hole needs to be punched outside the valve body and a pipe needs to be connected is abandoned, potential external leakage points are eliminated, the overall pressure-resistant sealing integrity of the valve is guaranteed, the pressure relief condition of the middle cavity can be accurately obtained, and the problem that the internal state of an all-welded or all-closed valve body is difficult to monitor is solved.

Description

Technical Field

[0001] This invention relates to the field of ball valve technology, and more specifically, to a split-type ball valve with an internal circulation pressure balance structure. Background Technology

[0002] Ball valves, as a critical fluid control and shut-off device, are widely used in harsh industrial environments such as petrochemicals, long-distance natural gas pipelines, deep-sea engineering, and power generation due to their excellent sealing performance and reliable opening and closing characteristics. In practical applications, especially in pipeline systems carrying high-pressure, large-diameter, and flammable, explosive, or highly corrosive media, ball valves commonly experience abnormal pressure rise in the cavity. This abnormal pressure rise can lead to a surge in valve operating torque, ball jamming, and in severe cases, even valve body rupture or seal failure, causing catastrophic media leakage accidents. Therefore, ball valves with pressure-balanced structures have become the preferred solution for critical nodes in the transportation of high-pressure, large-diameter, and highly hazardous media.

[0003] Existing pressure balancing structures typically employ two methods: one is to install an external pressure relief valve to discharge the medium in the central cavity to the outside of the pipeline or into the atmosphere, as illustrated in Chinese Patent Publication No. CN208831790U; the other is to open a one-way pressure relief hole on the valve ball or valve seat to release the high-pressure medium back into the upstream flow channel, as illustrated in Chinese Patent Publication No. CN216519707U. However, the first method compromises the integrity of the valve body, increases external leakage points and maintenance costs, and is unsuitable for toxic or hazardous media; while the second method achieves internal circulation pressure relief, for fully welded or fully enclosed valve bodies, operators cannot externally ascertain whether the pressure relief device is functioning correctly, nor can they monitor the actual pressure value inside the central cavity in real time.

[0004] Therefore, it is necessary to propose a split-type ball valve with an internal circulation pressure balance structure to at least partially solve the problems existing in the prior art. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To at least partially solve the above problems, the present invention provides a split-type ball valve with an internal circulation pressure balance structure, comprising a split-type valve body, a valve ball rotatably disposed inside the split-type valve body, and a valve seat for sealing the valve ball. A closed cavity is formed between the valve ball and the split-type valve body. A valve ball flow channel is provided at the center of the valve ball, and a medium flow channel is formed at the center of the split-type valve body. The invention also includes: An internal circulation pressure relief channel is provided on the solid wall of the valve ball and connects the middle cavity and the valve ball flow channel; The differential pressure relief component is located in the internal circulation pressure relief channel. It automatically opens when the pressure in the middle cavity exceeds the safety threshold and generates a sound wave signal in a specific frequency band. The monitoring unit is located on the outer wall of the split valve body and is used to capture the hydrodynamic noise of a preset frequency band generated when the differential pressure relief component is opened, and to identify the pressure state of the middle cavity based on the noise.

[0007] Preferably, the split valve body includes a main valve body and auxiliary valve bodies disposed on both sides of the main valve body, the main valve body and the auxiliary valve bodies are connected by fasteners; a valve stem is connected to the top of the valve ball, and the valve stem is fitted into a bearing seat on the upper part of the main valve body; a valve opening and closing handle is connected to the top of the valve stem.

[0008] Preferably, the internal circulation pressure relief channel is located on the non-sealed spherical surface of the valve ball and is positioned near the top of the valve ball.

[0009] Preferably, the internal circulation pressure relief channel is configured as a multi-segment stepped orifice, including a flared mounting section on the middle cavity side, a relief section on the valve ball flow channel side, and an inner conical sealing surface at the junction of the two.

[0010] Preferably, the differential pressure relief assembly includes a pressure relief valve core that slides within the flared mounting section and a spring coaxially sleeved thereon; the front end of the pressure relief valve core is configured as a sealing cone that mates with the inner conical sealing surface, and when the sealing cone is opened, it forms an annular jet gap with the inner conical sealing surface to generate high-frequency turbulent noise.

[0011] Preferably, the pressure relief valve core further includes a cylindrical guide section in the middle, and multiple axial flow guide grooves are formed on the outer circumference of the cylindrical guide section. The cross-section of the axial flow guide groove is set to rectangular and a step is formed at the outlet. When the medium flows through the axial flow guide groove, a whistle signal with a characteristic frequency is generated.

[0012] Preferably, the monitoring unit is configured as an acoustic emission sensor, and the monitoring unit is electrically connected to the control unit; the monitoring unit is installed on the outside of the split valve body and corresponds to the position of the internal circulation pressure relief channel.

[0013] Preferably, the outlet of the internal circulation pressure relief channel is connected to a limiting adjustment cover with a central opening, and the outer end face of the limiting adjustment cover does not exceed the outer spherical contour of the valve ball; the limiting adjustment cover is provided with an adjustment thread for adjusting the preload of the spring by changing the screw-in depth.

[0014] Preferably, the monitoring unit captures the hydrodynamic noise in a preset frequency band generated when the differential pressure relief component is activated, and identifies the pressure state of the middle cavity based on the noise, specifically including the following steps: The mapping relationship between the acoustic emission energy characteristic parameters of the differential pressure relief component under different opening degrees and the flow rate and differential pressure is pre-calibrated, and a coupled reference model is established. The monitoring unit collects vibration signals from the valve body surface and extracts high-frequency signal components that characterize the opening of the differential pressure relief assembly. Based on the energy amplitude of the extracted high-frequency signal components, the equivalent opening displacement of the pressure relief valve core is obtained by inversion using the coupled reference model. Based on the equivalent opening displacement of the pressure relief valve core, the spring stiffness coefficient, and the preload parameters, the fluid driving force required to maintain this opening displacement, i.e., the real-time fluid pressure value of the middle cavity, is calculated.

[0015] Preferably, the vibration signal of the valve body surface is acquired through the monitoring unit, specifically including: The characteristic whistling frequency range generated by the axial flow guide groove on the cylindrical guide section of the pressure relief valve core in the differential pressure relief assembly when the fluid passes through at high speed is determined in advance; When performing spectral analysis on the collected vibration signal, if a discrete peak is detected in the spectrum within the range of the characteristic howling frequency, and the signal-to-noise ratio of the peak exceeds a preset threshold, it is determined that the differential pressure relief component is activated, and the energy amplitude of that frequency band is extracted as the basis for inversion calculation.

[0016] Compared to existing technologies, this invention provides a split-type ball valve with an internal circulation pressure balancing structure, offering at least the following advantages: A differential pressure relief component is installed within the valve ball's solid wall, utilizing the ball structure itself as a pressure balancing carrier. This eliminates the traditional method of externally drilling holes for pipe connections, removing potential external leakage points and ensuring the overall pressure resistance and sealing integrity of the valve. Furthermore, an external monitoring unit utilizes the hydrodynamic noise generated during high-pressure fluid release as a signal source, converting the invisible pressure energy within the closed cavity into sound energy that can penetrate the metal wall and be perceived externally. This allows operators to accurately determine the pressure release status of the central cavity without entering the valve body, solving the problem of difficult monitoring of the internal state of fully welded or fully enclosed valve bodies and providing a definitive physical basis for safety assessment.

[0017] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1This is a schematic cross-sectional view of a split-type ball valve with an internal circulation pressure balance structure according to the present invention. Figure 1 ; Figure 2 This is a schematic cross-sectional view of a split-type ball valve with an internal circulation pressure balance structure according to the present invention. Figure 2 ; Figure 3 This is a schematic cross-sectional view of the differential pressure relief assembly in this invention. Figure 1 ; Figure 4 This is a schematic cross-sectional view of the differential pressure relief assembly in this invention. Figure 2 ; Figure 5 This is a schematic cross-sectional view of the internal circulation pressure relief channel in this invention. Figure 6 This is a schematic cross-sectional view of the pressure relief valve core at the cylindrical guide section in this invention.

[0019] In the diagram: 1. Split valve body; 2. Valve ball; 3. Valve seat; 4. Middle cavity; 5. Valve ball flow channel; 6. Medium flow channel; 7. Valve stem; 8. Valve opening / closing handle; 11. Main valve body; 12. Auxiliary valve body; 21. Internal circulation pressure relief channel; 22. Flared mounting section; 23. Discharge section; 24. Internal conical sealing surface; 30. Differential pressure relief assembly; 31. Pressure relief valve core; 32. Spring; 33. Sealing cone; 34. Cylindrical guide section; 35. Axial guide groove; 36. Limit adjustment cover; 50. Monitoring unit. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0021] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0022] Example 1: As Figures 1-6 As shown, this invention provides a split-type ball valve with an internal circulation pressure balance structure, comprising a split-type valve body 1, a valve ball 2 rotatably disposed inside the split-type valve body 1, and a valve seat 3 for sealing the valve ball 2. A closed central cavity 4 is formed between the valve ball 2 and the split-type valve body 1. A valve ball flow channel 5 is provided at the center of the valve ball 2, and a medium flow channel 6 is formed at the center of the split-type valve body 1. It also includes: The internal circulation pressure relief channel 21 is located on the solid wall of the valve ball 2 and connects the middle cavity 4 and the valve ball flow channel 5; The differential pressure relief component 30 is located in the internal circulation pressure relief channel 21. It automatically opens when the pressure in the middle cavity 4 exceeds the safety threshold and generates a sound wave signal in a specific frequency band. The monitoring unit 50 is disposed on the outer wall of the split valve body 1 and is used to capture the hydrodynamic noise of the preset frequency band generated when the differential pressure relief component 30 is opened, and to identify the pressure state of the middle cavity based on the noise.

[0023] The working principle and beneficial effects of the above technical solution are as follows: This embodiment provides a split-type ball valve with an internal circulation pressure balance structure. The valve ball 2 and the split-type valve body 1 enclose a closed cavity 4, where the medium remains. When the ambient temperature rises or the operating conditions fluctuate, causing the medium in the cavity 4 to expand due to heat, the static pressure of the fluid in the cavity 4 gradually increases. This fluid pressure acts directly on the inlet end of the internal circulation pressure relief channel 21 and is transmitted to the pressure-bearing surface of the differential pressure relief assembly 30 located in the channel. As the pressure in the cavity 4 continues to rise, the fluid thrust acting on the differential pressure relief assembly 30 also increases.

[0024] When the fluid thrust exceeds the safety threshold set inside the differential pressure relief assembly 30, the differential pressure relief assembly 30 is displaced axially, causing the internal circulation relief channel 21 to be in a conductive state. At this time, the high-pressure fluid is injected at high speed from the middle cavity 4 into the valve ball flow channel 5 with relatively low pressure through the internal circulation relief channel 21, completing the internal circulation relief of pressure.

[0025] When fluid flows at high speed through the opening of the differential pressure relief assembly 30, shearing and turbulence occur, inducing hydrodynamic noise, which includes sound wave signals in a specific frequency band. The sound wave signals are transmitted sequentially through the solid metal wall of the valve ball 2 and the valve seat 3 to the split valve body 1. The monitoring unit 50, located on the outer wall of the split valve body 1, captures the hydrodynamic noise signal in the preset frequency band and converts the mechanical vibration into an electrical signal output, determining that the pressure in the middle cavity 4 exceeds the safety threshold. When the pressure in the middle cavity 4 is released to the point that the fluid thrust is less than the closing holding force, the differential pressure relief assembly 30 moves in the opposite direction under the action of the restoring force, re-closing the inner circulation pressure relief channel 21, the fluid flow stops, and the sound wave signals disappear.

[0026] This embodiment utilizes a differential pressure relief component 30 installed within the solid wall of the valve ball 2, employing the valve ball 2 structure itself as a pressure balance carrier. This eliminates the traditional pressure relief method requiring external drilling and piping, thus removing potential external leakage points and ensuring the overall pressure resistance and sealing integrity of the valve. An external monitoring unit 50 is installed, using the hydrodynamic noise generated during high-pressure fluid release as a signal source. This converts the invisible pressure energy within the closed cavity into sound energy that can penetrate the metal wall and be perceived externally. This allows operators to accurately determine the pressure release status of the central cavity 4 without entering the valve body, solving the problem of difficult monitoring of the internal state of fully welded or fully enclosed valve bodies and providing a definitive physical basis for safety assessment.

[0027] Example 2: Based on Example 1 above, the split valve body 1 includes a main valve body 11 and a secondary valve body 12 disposed on both sides of the main valve body 11. The main valve body 11 and the secondary valve body 12 are connected by fasteners. The valve ball 2 is connected to the top of a valve stem 7, and the valve stem 7 is fitted into a bearing seat on the upper part of the main valve body 11. The top of the valve stem 7 is connected to a valve opening and closing handle 8.

[0028] The internal circulation pressure relief channel 21 is located on the non-sealing spherical surface of the valve ball 2 and is positioned near the top of the valve ball 2.

[0029] The monitoring unit 50 is configured as an acoustic emission sensor and is electrically connected to the control unit. The monitoring unit 50 is installed on the outside of the split valve body 1 and corresponds to the position of the internal circulation pressure relief channel 21.

[0030] The working principle and beneficial effects of the above technical solution are as follows: The split valve body 1 adopts a split structure of main valve body 11 and auxiliary valve body 12. During assembly, the valve ball 2 is placed into the main valve body 11, and then the auxiliary valve body 12 is connected to the main valve body 11 by fasteners, thus completing the encapsulation of the valve ball 2 and valve seat 3. The valve stem 7 passes through the bearing hole at the top of the main valve body 11 and connects to the valve ball 2. The handle 8 drives the valve stem 7 to rotate.

[0031] The internal circulation pressure relief channel 21 is located in the non-sealed spherical area near the top of the valve ball 2. The monitoring unit 50 is an acoustic emission sensor, installed on the outside of the main valve body 11 in the area corresponding to the center of the top of the valve ball 2.

[0032] During valve operation, if gas-liquid separation or sediment accumulation occurs in the medium within the central cavity 4, the gaseous medium naturally rises to the top of the central cavity, while the sediment sinks to the bottom. When pressure rises and triggers pressure relief, the internal circulation pressure relief channel 21 located at the top preferentially contacts and discharges the upper gas phase or clean medium, preventing impurities at the bottom from entering the channel and causing blockage. Simultaneously, because the opening of this channel is located on a non-sealing spherical surface, throughout the entire opening and closing process of the valve ball 2, the opening edge of the internal circulation pressure relief channel 21 never passes through the main sealing strip of the valve seat 3, preventing the metal orifice edge from scratching the soft sealing material.

[0033] In this embodiment, the internal circulation pressure relief channel 21 is arranged in the non-sealing area at the top of the valve ball. This utilizes the geometric redundancy of the ball valve structure to achieve spatial isolation between the pressure relief function and the sealing function, avoiding the risk of sealing ring cutting and wear caused by opening holes, and extending the service life of the valve. Furthermore, the monitoring unit 50 is positioned close to the internal circulation pressure relief channel 21 to shorten the transmission path as much as possible, minimizing energy loss of sound waves during transmission through multiple interfaces and ensuring a high signal-to-noise ratio for the signal received by the sensor.

[0034] Example 3: Based on Example 1 above, the internal circulation pressure relief channel 21 is configured as a multi-segment stepped hole, including a flared mounting section 22 located on the side of the middle cavity 4, a relief section 23 located on the side of the valve ball flow channel 5, and an inner conical sealing surface 24 located at the junction of the two.

[0035] The differential pressure relief assembly 30 includes a pressure relief valve core 31 that slides within the flared mounting section 22 and a spring 32 that is coaxially sleeved. The front end of the pressure relief valve core 31 is configured as a sealing cone 33 that mates with the inner conical sealing surface 24. When the sealing cone 33 is open, it forms an annular jet gap with the inner conical sealing surface 24 to generate high-frequency turbulent noise.

[0036] The outlet of the internal circulation pressure relief channel 21 is connected to a limiting adjustment cover 36 with a central opening. The outer end face of the limiting adjustment cover 36 does not exceed the outer spherical contour of the valve ball 2. The limiting adjustment cover 36 is provided with an adjustment thread for adjusting the preload of the spring 32 by changing the screw-in depth.

[0037] The working principle and beneficial effects of the above technical solution are as follows: The internal circulation pressure relief channel 21 is machined into a multi-segment stepped hole. Fluid enters the flared mounting section 22 from the side of the central cavity 4, passes through the inner conical sealing surface 24 in the middle, and finally leads to the relief section 23 on the side of the valve ball flow channel 5. The differential pressure relief assembly 30 includes a pressure relief valve core 31, a spring 32, and a limit adjustment cover 36. In the initial state, the limit adjustment cover 36 is screwed into the end of the flared mounting section 22, compressing the spring 32 and generating a preload force, which presses the sealing cone 33 at the front end of the pressure relief valve core 31 against the inner conical sealing surface 24.

[0038] When the pressure in the middle cavity 4 increases, the thrust generated by the fluid pressure acting on the pressure-bearing surface of the pressure relief valve core 31 overcomes the spring preload and friction, causing the pressure relief valve core 31 to retract. The sealing cone 33 disengages from the inner conical sealing surface 24, instantly forming an extremely narrow annular jet gap between them. When the high-pressure fluid flows through this annular gap, the flow velocity increases dramatically, generating high-frequency turbulent noise. Subsequently, the fluid enters the discharge section 23 and is discharged.

[0039] If the opening pressure needs to be adjusted, the compression of the spring 32 is changed by altering the screw-in depth of the limit adjustment cover 36. The outer end face of the limit adjustment cover 36 is designed to be recessed or flush with the outer contour of the valve ball 2 to ensure that no mechanical interference occurs when the valve ball 2 rotates.

[0040] This embodiment ensures high airtightness when closed by combining a conical seal with spring preload, and forms an annular jet gap at the moment of opening, enhancing the energy density of hydrodynamic noise and solving the problem that the noise signal is too weak to be captured by external sensors at low flow rates. At the same time, the embedded position adjustment cover 36 makes the pressure threshold of this structure adjustable without damaging the outer envelope of the valve ball 2.

[0041] Example 4: Based on Example 3 above, the pressure relief valve core 31 further includes a cylindrical guide section 34 in the middle. Multiple axial flow guide grooves 35 are formed on the outer circumferential surface of the cylindrical guide section 34. The cross-section of the axial flow guide groove 35 is set to rectangular and a step is formed at the outlet. When the medium flows through the axial flow guide groove 35, a whistle signal with a characteristic frequency is generated.

[0042] The working principle and beneficial effects of the above technical solution are as follows: The cross-section of the axial guide channel 35 is precision machined into a rectangle, and a sharp step or separation edge is machined at the end of the channel, i.e., on the side near the discharge section.

[0043] When the pressure relief valve core 31 opens, the fluid enters the axial guide channel 35 at high speed after passing through the annular jet gap. Due to the sudden change in the flow channel cross-section and the constraint of the rectangular channel wall, the fluid is rectified and accelerated within the channel. When the high-speed fluid flows past the stepped edge at the channel outlet, hydroacoustic resonance occurs, generating a high-intensity narrow-band whistle signal with a specific frequency. This signal frequency mainly depends on the flow velocity and the geometry of the guide channel 35 (channel width, step distance).

[0044] This embodiment modifies a conventional pressure relief channel into a hydrodynamic whistle generator. This structure can actively modulate a narrowband signal with a specific acoustic fingerprint at the moment of pressure relief, rather than ordinary broadband white noise. This greatly improves the signal's recognizability, allowing the monitoring system to easily isolate the pressure relief action from background environmental noise (such as pump vibration and fluid scouring sound), ensuring the uniqueness of the monitoring results and its anti-interference capability.

[0045] Example 5: Based on Example 4 above, the monitoring unit 50 captures the hydrodynamic noise in a preset frequency band generated when the differential pressure relief assembly 30 is turned on, and identifies the pressure state of the middle cavity based on the noise. Specifically, it includes the following steps: The mapping relationship between the acoustic emission energy characteristic parameters of the differential pressure relief component 30 under different opening degrees and the flow rate and differential pressure is pre-calibrated, and a coupled reference model is established. The monitoring unit 50 collects vibration signals from the valve body surface and extracts high-frequency signal components that characterize the opening of the differential pressure relief assembly 30. Based on the energy amplitude of the extracted high-frequency signal components, the equivalent opening displacement of the pressure relief valve core 31 is obtained by inversion using the coupled reference model. Based on the equivalent opening displacement of the pressure relief valve core 31, the spring stiffness coefficient, and the preload parameters, the fluid driving force required to maintain the opening displacement, i.e., the real-time fluid pressure value of the middle cavity 4, is calculated.

[0046] The monitoring unit 50 collects vibration signals from the valve body surface, specifically including: The characteristic whistling frequency range generated by the axial flow guide groove 35 on the cylindrical guide section 34 of the pressure relief valve core 31 in the differential pressure relief assembly 30 when the fluid passes through at high speed is determined in advance; When performing spectral analysis on the collected vibration signal, if a discrete peak is detected in the spectrum within the range of the characteristic howling frequency, and the signal-to-noise ratio of the peak exceeds a preset threshold, it is determined that the differential pressure relief component 30 is activated, and the energy amplitude of the frequency band is extracted as the basis for inversion calculation.

[0047] The working principle and beneficial effects of the above technical solution are as follows: The monitoring process is divided into a calibration phase and a real-time monitoring phase. In the calibration phase, the opening displacement, flow rate, and corresponding acoustic emission energy characteristics (RMS values) of the differential pressure relief component 30 under different differential pressure driving conditions are tested on the experimental bench beforehand, and a database is established. Simultaneously, the characteristic whistling frequency range excited by the axial guide channel 35 within the working flow rate range is measured.

[0048] During the real-time monitoring phase, the monitoring unit 50 continuously acquires vibration signals from the valve body surface. The processor first performs a Fast Fourier Transform (FFT) on the signal to obtain a spectrum. The algorithm searches the spectrum for discrete peaks located within the characteristic whistling frequency range. If a peak with a signal-to-noise ratio exceeding a preset threshold is detected within this frequency band, it is determined to be a true pressure relief signal, confirming that the differential pressure relief component 30 has been activated.

[0049] Subsequently, the system extracts the signal energy amplitude within this characteristic frequency band. Using a pre-stored coupling reference model, the acoustic energy amplitude is mapped and converted into the current equivalent opening displacement of the pressure relief valve core 31. Finally, based on Hooke's law and the principle of force balance, the spring force is calculated using the displacement, spring stiffness coefficient, and preload compression. This spring force is approximately equal to the fluid driving force in equilibrium. This force is then divided by the pressure-bearing area of ​​the pressure relief valve core to calculate the real-time fluid pressure value of the middle cavity 4, which is then output to the control terminal.

[0050] For example, by selecting a specific slot width (e.g., 1-2 mm) and spring stiffness (which determines the flow rate when opening), the characteristic frequency of the pressure relief valve core 31 at the initial opening stage is locked in the acoustic frequency band of 25 kHz to 40 kHz. When performing signal processing, the monitoring unit 50 performs spectral analysis on the acquired vibration signal and determines that the differential pressure relief component 30 is open only when a discrete peak in the 25 kHz-40 kHz range is detected in the spectrum, and the signal-to-noise ratio of the peak exceeds a preset threshold (e.g., 6 dB).

[0051] During the monitoring process, the monitoring unit 50 extracts the root mean square (RMS) value of the signal within the characteristic frequency band (such as 25kHz-40kHz), and obtains the current equivalent opening displacement of the pressure relief valve core 31 by looking up a table based on the correlation between the fluid jet noise power and the gap opening.

[0052] According to Hooke's Law and the force analysis of the pressure relief valve core, the pressure relief valve core 31 satisfies the following mechanical equilibrium equation in the open equilibrium state: in: The real-time pressure of the cavity to be determined; This refers to the pressure-bearing area of ​​the pressure relief valve core. This is the spring stiffness coefficient; This is the opening displacement obtained through inversion; This is the spring pre-compression amount (determined by the position of the adjusting cover); For kinetic friction (which can be set as constant or relative to...) (functions) The preset back pressure on the flow channel side (this value can be a known pipeline working pressure constant, or approximately zero under specific low-pressure discharge conditions).

[0053] By solving the above equations, the pressure in the middle cavity can be calculated in real time. .

[0054] This embodiment addresses the shortcomings of the single energy detection method, which is prone to false alarms, by combining frequency domain fingerprint verification with energy inversion calculation. By first verifying frequency characteristics, false signal interference from mechanical loosening or external impacts is eliminated. Furthermore, by establishing an acoustic-mechanical coupling model, qualitative acoustic signals are converted into quantitative pressure values. This imbues the pressure relief valve, acting as a safety protection device, with the functionality of a precision sensor, enabling pressure management within a closed cavity without disrupting pressure boundaries or increasing the intrusion of electronic sensors.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A split ball valve with internal circulation pressure balance structure, comprising: a split valve body (1), a valve ball (2) rotatably arranged inside the split valve body (1), and a valve seat (3) for sealing the valve ball (2), a closed cavity (4) being formed between the valve ball (2) and the split valve body (1), a valve ball flow passage (5) being arranged at the center of the valve ball (2), and a medium flow passage (6) being formed at the center of the split valve body (1); characterized in that further comprising: an internal circulation pressure relief channel (21) arranged on the solid wall of the valve ball (2) and communicating with the cavity (4) and the valve ball flow passage (5); a differential pressure relief assembly (30) arranged in the internal circulation pressure relief channel (21), which is automatically opened when the pressure in the cavity (4) exceeds a safety threshold, and generates a specific frequency acoustic signal; and a monitoring unit (50) arranged on the outer wall of the split valve body (1), which is used to capture the fluid dynamic noise of the preset frequency generated when the differential pressure relief assembly (30) is opened, and identify the pressure state in the cavity based on the noise. The split valve body (1) comprises a main valve body (11) and a secondary valve body (12) arranged on both sides of the main valve body (11), the main valve body (11) and the secondary valve body (12) are connected by fasteners; the valve ball (2) is connected with a valve stem (7) at the top, and the valve stem (7) is fitted into a bearing seat arranged on the upper part of the main valve body (11); a valve opening and closing handle (8) is connected to the top end of the valve stem (7). The internal circulation pressure relief channel (21) is arranged on the non-sealing surface of the valve ball (2) and close to the top of the valve ball (2). The internal circulation pressure relief channel (21) is arranged as a multi-section stepped hole, comprising a flared mounting section (22) on the side of the cavity (4), a relief section (23) on the side of the valve ball flow passage (5), and an inner conical sealing surface (24) at the junction of the two. The differential pressure relief assembly (30) comprises a relief valve core (31) slidingly fitted in the flared mounting section (22) and a spring (32) coaxially sleeved; the front end of the relief valve core (31) is provided with a sealing cone head (33) matched with the inner conical sealing surface (24), and when the sealing cone head (33) is opened, an annular jet gap is formed between the sealing cone head (33) and the inner conical sealing surface (24) to generate high-frequency turbulent noise.

2. The split ball valve having an internal circulation type pressure balance structure according to claim 1, wherein The relief valve core (31) further comprises a cylindrical guide section (34) in the middle, a plurality of axial guide grooves (35) are arranged on the outer circumferential surface of the cylindrical guide section (34), the cross section of the axial guide grooves (35) is arranged as a rectangle and forms a step at the outlet, and a whistle signal with a characteristic frequency is generated when the medium flows through the axial guide grooves (35).

3. The split ball valve having an internal circulation type pressure balance structure according to claim 2, wherein The monitoring unit (50) is arranged as an acoustic emission sensor, and the monitoring unit (50) is electrically connected with a control unit; the monitoring unit (50) is installed on the outer side of the split valve body (1) and corresponds to the position of the internal circulation pressure relief channel (21).

4. The split ball valve having an internal circulation type pressure balance structure according to claim 1, wherein ​ 5. The split ball valve having an internal circulation type pressure balance structure according to claim 4, wherein ​ 6. The split ball valve having an internal circulation type pressure balance structure according to claim 5, wherein ​ 7. The split ball valve having an internal circulation type pressure balance structure according to claim 1, wherein ​ 8. The split ball valve having an internal circulation type pressure balance structure according to claim 4, wherein The inner circulation pressure relief channel (21) is connected with a center-opening limiting adjusting cover (36) at the outlet, the outer end surface of the limiting adjusting cover (36) does not exceed the outer spherical surface profile of the valve ball (2), the limiting adjusting cover (36) is provided with adjusting threads, and the pre-tightening force of the spring (32) is adjusted by changing the screwing depth.

9. The split ball valve having an internal circulation type pressure balance structure according to claim 6, wherein The monitoring unit (50) captures fluid dynamic noise of a preset frequency band generated when the differential pressure relief assembly (30) is opened, and identifies the pressure state of the middle cavity based on the noise, specifically including the following steps: The mapping relationship between the acoustic emission energy characteristic parameters of the differential pressure relief assembly (30) at different opening degrees and the through flow and pressure difference is calibrated in advance, and a coupling reference model is established; The vibration signal of the valve body surface is collected by the monitoring unit (50), and a high-frequency signal component representing the opening of the differential pressure relief assembly (30) is extracted; Based on the energy amplitude of the extracted high-frequency signal component, the equivalent opening displacement amount of the relief valve core (31) is obtained by using the coupling reference model; Based on the equivalent opening displacement amount of the relief valve core (31), the spring stiffness coefficient and the pre-tightening force parameters, the fluid driving force required to maintain the opening displacement, i.e. the real-time fluid pressure value of the middle cavity (4), is calculated.

10. The split ball valve having an internal circulation type pressure balance structure according to claim 9, wherein The vibration signal of the valve body surface is collected by the monitoring unit (50), specifically including: The characteristic howling frequency range generated by the axial flow guide groove (35) on the cylindrical guide section (34) of the relief valve core (31) in the differential pressure relief assembly (30) when high-speed fluid passes through is determined in advance; When performing frequency spectrum analysis on the collected vibration signal, only when it is detected that there is a discrete peak value in the frequency spectrum within the characteristic howling frequency range, and the signal-to-noise ratio of the peak value exceeds the preset threshold, it is determined that the differential pressure relief assembly (30) is opened, and the energy amplitude of the frequency band is intercepted as the basis for inversion calculation.

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