Measuring device for sound velocity in middle-high pressure hydraulic pipeline

Abstract

The utility model discloses a device for measuring sound velocity in a middle-high pressure hydraulic pipeline, which relates to the technical field of measuring devices and comprises a driving shaft, a rotary valve, a transition end cover, a hydraulic pipeline, a first fiber bragg grating sensor and a second fiber bragg grating sensor. An axial output port of the rotary valve is connected with a transition end cover, and the transition end cover is connected with a hydraulic pipeline; the front end of the hydraulic pipeline is connected with a first fiber grating sensor, and the tail end is connected with a second fiber grating sensor; the rotary valve comprises a valve cover, a valve body, and a rotary valve core and a bearing which are arranged in the valve body; the driving shaft is connected with the rotary valve element, and an explosion flushing cavity and a low-pressure cavity which are isolated from each other are formed in the rotary valve element; the blasting cavity is provided with a first conical nozzle, and the low-pressure cavity is provided with a second conical nozzle; an axial output port of the rotary valve is provided with a third conical nozzle; the transition end cover is provided with a fourth conical nozzle; measurement of the propagation sound velocity of oil in a hydraulic pipeline under a certain pressure is realized.

Description

Technical Field

[0001] This application belongs to the field of measuring device technology, specifically relating to a measuring device for sound velocity in a medium- or high-pressure hydraulic pipeline. Background Technology

[0002] Research in AC hydraulics, including theories on AC pulsation and methods to improve the accuracy and stability of pulses, as well as discrete flow research on the discretized transmission of hydraulic fluids (similar to AC hydraulics), all rely on a deep understanding and measurement of the accuracy and stability of fluid pulses or pulsations within hydraulic lines. Measuring the formation and propagation speed of pulses within hydraulic lines has always been challenging. Accurately obtaining the velocity of sound in the hydraulic fluid would allow for the measurement of the hydraulic noise characteristics of hydraulic components and systems with appropriate precision.

[0003] In the design of the Zhejiang University pressure pulsation test bench, since the pressure pulsation of the hydraulic system pump source is difficult to measure directly and accurately, the test equipment adopts a "dual-pressure, dual-system" test scheme. Pressure pulsation is indirectly obtained by testing the source flow pulsation and source impedance of the motor pump or hydraulic pump under test. This pressure pulsation test bench is mainly used to test the pump source pressure pulsation of a certain model of motor pump with noise control requirements, providing experimental basis for continuous optimization and noise reduction of servo systems.

[0004] "Determination of Noise Characteristics of Hydraulic Transmission Fluids, Part 2: Measurement of Sound Velocity in Pipelines" describes a method for measuring the sound velocity in a fluid enclosed within a pipeline using a pressure sensor installed in the pipeline. This method is based on the application of plane wave transmission line theory to the analysis of pressure fluctuations in hydraulic fluid within rigid pipelines to determine the sound velocity in the pipeline fluid. To obtain the transmitted wave source, a hydraulic noise generator is needed to induce pressure fluctuations in the loop through flow fluctuations, or to directly induce flow fluctuations through pressure fluctuations in the loop. These fluctuations all contain clutter or harmonics, and their wave velocities require simplified conditions and relatively complex auxiliary calculations to obtain indirectly.

[0005] In other words, there is currently no effective means to measure the propagation speed of a sound pulse in oil. The speed of sound in metals is calculated as c = √K. e / ρ cannot be used for oils because it is generally assumed that the oil pressure varies. Although the density ρ of an oil can be approximated as stable, the elastic modulus K of the oil... e The variation is significant, especially the free air content, which has the greatest impact. Therefore, the propagation speed of the pulse varies under different pressures.

[0006] In discrete flow research, the discretized transmission of hydraulic fluid requires a method and apparatus for calculating the velocity of sound within medium- and high-pressure hydraulic pipelines to effectively utilize the high-speed propagation of pulses. The velocity of sound in metals is c = √K. eThe calculated value of / ρ is relatively high. Currently, for measuring high-speed motion, such as the speed of light, the Fizeau gear method or rotating mirror method are generally used. Both methods assume that the speed of light traveling and the speed of reflected light are the same. By measuring the distance L traveled and the time t taken for reflection, c = L / t can be calculated using a simple division. For a finite distance L and a high speed c, the measurement time t will be very short. Therefore, a measuring device with a very high scanning speed is required to ensure its feasibility.

[0007] The scanning cycle of a spectrometer typically refers to the time required for the spectrometer to complete one scan. The specific time depends on factors such as the spectrometer's scanning speed and wavelength range. For example, some spectrometers may have a scanning time of only 100 milliseconds. With technological advancements, the scanning time of spectrometers abroad can now reach 9 μs, while domestic spectrometers can achieve millisecond-level scanning times. This provides a fundamental support for measuring the propagation speed of pressure pulsations within hydraulic lines. Utility Model Content

[0008] This application provides a device for measuring the sound velocity in a medium- or high-pressure hydraulic pipeline to solve the problem of measuring the sound velocity of pulsating flow required for the realization of high-speed discrete transmission of hydraulic fluid in the above-mentioned technical problem, and thus requires a device for measuring the sound velocity in a medium- or high-pressure hydraulic pipeline.

[0009] The technical solution adopted in this application is as follows:

[0010] A device for measuring the velocity of sound in a medium- or high-pressure hydraulic pipeline includes a drive shaft, a rotary valve, a transition end cap, a hydraulic pipeline, a first fiber Bragg grating sensor, and a second fiber Bragg grating sensor. The axial output port of the rotary valve is connected to the transition end cap, which is connected to the hydraulic pipeline. The front end of the hydraulic pipeline is connected to the first fiber Bragg grating sensor, and the rear end is connected to the second fiber Bragg grating sensor. The rotary valve includes a valve cover, a valve body, a rotary valve core disposed within the valve body, and a bearing. The drive shaft is connected to the rotary valve core, which has a pressure chamber and a low-pressure chamber isolated from each other. The pressure chamber has a first conical nozzle, and the low-pressure chamber has a second conical nozzle. The axial output port of the rotary valve has a third conical nozzle, and the transition end cap has a fourth conical nozzle.

[0011] The rotary valve is configured to: control the rotation of the rotary valve core via the rotation of the drive shaft, thereby forming a Laval tube with the first and third conical nozzles, and a spindle-shaped pulse-controlling chamber with the third and fourth conical nozzles. The fourth conical nozzle is connected to the hydraulic pipeline, and the pulse-controlling chamber contains hydraulic oil from the hydraulic pipeline. When the hydraulic oil in the burst chamber is injected into the pulse-controlling chamber, it pushes the hydraulic oil in the pulse-controlling chamber through the fourth conical nozzle into the hydraulic pipeline to form an impact pulsating flow, presenting an injection state where the rotary valve outputs pulsating flow to the hydraulic pipeline; or, the second and third conical nozzles form a Laval tube to allow the pulsating flow from the hydraulic pipeline to enter the low-pressure chamber after passing through the spindle-shaped pulse-eliminating chamber formed by the fourth and third conical nozzles, presenting a recovery state where the pulsating flow enters the low-pressure chamber; or, a closed state where the third conical nozzle is closed, which is between the two states.

[0012] The hydraulic oil pressure, hydraulic pulse amplitude, and number of pulses in the hydraulic pipeline are scanned, measured, and recorded by the first fiber optic grating sensor and the second fiber optic grating sensor, so as to realize the measurement of the propagation speed of sound in the hydraulic oil in the hydraulic pipeline under a certain pressure.

[0013] The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline disclosed in this application also has the following additional technical features:

[0014] The rotary valve core is also provided with a first fluid channel communicating with the bursting chamber and a second fluid channel communicating with the low-pressure chamber.

[0015] The valve body has a first flow channel connected to the first fluid channel along its circumference, so that hydraulic oil with a pressure greater than that of the constant pressure oil source enters the burst chamber through the first flow channel; the valve body also has a second flow channel connected to the second fluid channel along its circumference, so that hydraulic oil in the low pressure chamber flows back to the oil tank through the second fluid channel.

[0016] A one-way valve is installed in the first fluid channel so that the hydraulic oil in the explosion chamber does not flow back to the hydraulic oil source when the hydraulic oil in the explosion chamber is impacted. During the rotation of the rotary valve, the explosion chamber always receives the replenishment or supply of high-pressure oil from the hydraulic oil source through the one-way valve.

[0017] The second flow channel is equipped with a back pressure valve that connects the low-pressure chamber to the second flow channel, so as to ensure that the oil flowing back to the oil tank through the back pressure valve has a certain back pressure in the low-pressure chamber.

[0018] The explosive chamber is connected to a diaphragm that divides the explosive chamber into a gas chamber and a liquid chamber, and a rotary valve core.

[0019] An air inlet is provided that communicates with the air chamber.

[0020] The inner wall of the gas chamber of the explosive chamber is formed with an arc surface on one side, and the inner wall of the liquid chamber of the explosive chamber has a first conical surface and a second conical surface connected along the axial direction. The first conical surface is connected to the arc surface, and the inner diameter of the explosive chamber gradually decreases from the first conical surface to the second conical surface.

[0021] A blind hole is provided at the end of the hydraulic pipeline, and a second fiber optic grating sensor is installed inside the blind hole. An external constant pressure oil source supplies hydraulic oil to the hydraulic pipeline through a bypass check valve at the blind hole end of the hydraulic pipeline. When the air that needs to be discharged from the hydraulic pipeline is rotated to the recovery state by the rotary valve, it passes through the pulse control chamber, the low pressure chamber, the second fluid channel, the back pressure valve, and the second flow channel, and then is discharged from the open oil tank.

[0022] At least two sets of centering bearings are connected to the outer periphery of the rotary valve core along the axial direction to support the rotation of the rotary valve core; at least two sets of thrust bearings are respectively provided at both ends of the rotary valve core, and the thrust bearing at the valve cover end pushes the rotary valve core through the valve cover to ensure that the dynamic and static sealing rings between the rotary valve core and the inner end face of the valve body are in tight contact; the thrust bearing connected to the inner end face of the valve body is used to ensure that there is sufficient clearance between the rotary valve core and the inner end face of the valve body to reduce friction.

[0023] The rotary valve core has anti-friction grooves on its circumference. The anti-friction grooves are connected to the low-pressure chamber through a third fluid channel, so that there is a certain pressure of oil in the anti-friction grooves. This allows the rotary valve core to be suspended in the circumferential hole of the valve body with the help of the pressure oil, and to leak into the centering bearing and thrust bearing that support the rotation of the rotary valve core, so as to provide lubrication for the bearings.

[0024] At least two sets of dynamic sealing structures are spaced radially between the coaxial annular surfaces of the rotary valve core and the valve body. The rotary annular surface where the third conical nozzle is located is positioned between the two sets of dynamic sealing structures to ensure that the oil in the third conical nozzle is not disturbed by external oil.

[0025] A dynamic sealing structure is provided at intervals along the axial direction between the rotary valve core and the circumferential surface of the valve body; there are at least two pairs of dynamic sealing structures on both sides of the first flow channel; and at least two pairs of dynamic sealing structures on both sides of the second flow channel.

[0026] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0027] 1. A sound velocity measuring device in a medium-high pressure hydraulic pipeline according to this application includes a drive shaft, a rotary valve, a transition end cap, a hydraulic pipeline, a first fiber Bragg grating sensor, and a second fiber Bragg grating sensor; the rotary valve core has a separately isolated burst chamber and a low-pressure chamber; the burst chamber contains compressed gas capable of bursting, similar to the expanding gas after the gunpowder explodes in a revolver, to utilize the injection of hydraulic fluid; the burst chamber is connected to an external pipeline, allowing the burst chamber to emit a single pulse; by rotating the valve core, the burst chamber and the low-pressure chamber are alternately connected to the external pipeline, which can... The modulation of the emission pulse period allows the pressure in the hydraulic lines to be "artificially" and controllably inserted with pressure markers for calculating cycle time, which facilitates the measurement of time or period; the second and third conical nozzles form a Laval tube to accelerate the pulsating flow of the hydraulic lines; the third and fourth conical nozzles can form a pulse-controlling chamber, the liquid inside which is similar to the bullet in a revolver; the fourth and third conical nozzles can also form a pulse-extinguishing chamber, similar to a silencer formed by the changing space of the bullet gas inside the barrel;

[0028] 2. As a preferred embodiment of this application, the rotary valve core is further provided with a first fluid channel communicating with the burst chamber and a second fluid channel communicating with the low-pressure chamber; a first flow channel communicating with the first fluid channel is provided circumferentially in the valve body, so that hydraulic oil with a pressure greater than that of the constant pressure oil source enters the burst chamber through the first flow channel; a second flow channel communicating with the second fluid channel is also provided circumferentially in the valve body, so that hydraulic oil flows back to the oil tank through the second fluid channel, which can eliminate free air bubbles in the hydraulic oil of the hydraulic pipeline, and rapidly attenuate the hydraulic oil pulsation in the hydraulic pipeline, or eliminate the influence of the "ammunition" in the burst chamber on the hydraulic oil pressure increase of the hydraulic pipeline by the oil flowing back to the oil tank, thereby achieving the stabilization or constant pressure in the pipeline.

[0029] The rotary valve core is provided with a first fluid channel to form an input channel, which can continuously input the hydraulic oil source of constant pressure oil source into the explosion chamber, ensuring the timely filling of "ammunition" in the explosion chamber and the stability of pressure energy, providing a new way to prepare single or continuous pulse impacts.

[0030] 3. In a preferred embodiment of this application, a check valve is provided in the first fluid channel to prevent the hydraulic oil in the explosion chamber from flowing back to the hydraulic oil source when it is impacted. During the rotation of the rotary valve, the explosion chamber always receives the replenishment or supply of high-pressure oil from the hydraulic oil source through the check valve, ensuring the pressure stability of the hydraulic oil source and the energy concentration of the energy group delivered to the hydraulic pipeline through the explosion chamber, without bypass overflow. A back pressure valve is provided in the second flow channel to connect the low-pressure chamber and the second flow channel, so as to ensure that the oil flowing back to the oil tank through the back pressure valve has a certain back pressure in the low-pressure chamber. This back pressure, on the one hand, prevents the oil flowing back to the oil tank through the low-pressure chamber from flowing too fast and generating air bubbles, and on the other hand, ensures that the oil in the low-pressure chamber can provide lubrication for the bearing.

[0031] 4. In a preferred embodiment of this application, a diaphragm is connected inside the explosion chamber, dividing the explosion chamber into a gas chamber and a liquid chamber. The liquid chamber is filled with hydraulic oil, and the gas chamber is filled with gas. This effectively utilizes the characteristic that the compression ratio of gas is greater than that of oil to ensure that the explosion chamber delivers a sufficient volume of energy to the hydraulic pipeline. The rotary valve core has an air inlet that communicates with the gas chamber, so that the pressure or volume of the gas in the gas chamber can be easily adjusted through the air inlet.

[0032] 5. As a preferred embodiment of this application, a blind hole is provided at the tail end of the hydraulic pipeline, and a bypass check valve is provided at the blind hole end. The bypass check valve allows an external constant pressure oil source to supply hydraulic oil to the hydraulic pipeline, allowing air in the hydraulic pipeline to enter from the closed blind end and flow back to the oil tank from the low pressure chamber, thereby achieving the purpose of removing air bubbles and flushing. On the other hand, when the front end of the hydraulic pipeline is closed, the bypass check valve can provide a stable and constant pressure to the hydraulic oil in the hydraulic pipeline, while ensuring that the hydraulic oil in the hydraulic pipeline will not backflow and contaminate the constant pressure oil source through the bypass check valve. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0034] Figure 1 This is a schematic diagram of the structure of a sound velocity measuring device in a medium- or high-pressure hydraulic pipeline according to this application.

[0035] In the picture,

[0036] 1. Drive shaft; 2. Rotary valve; 21. Valve cover; 22. Valve body; 23. Rotary valve core; 3. Transition valve cover; 4. Hydraulic pipeline; 5. First fiber Bragg grating sensor; 6. Second fiber Bragg grating sensor; 7. Burst chamber; 71. Gas chamber; 72. Liquid chamber; 8. Low-pressure chamber; 9. First conical nozzle; 10. Second conical nozzle; 11. Third conical nozzle; 12. Fourth conical nozzle; 13. Laval pipe; 14. First fluid passage 15. Second fluid channel; 16. First flow channel; 17. Second flow channel; 18. Oil tank; 19. Constant pressure oil source; 20. Hydraulic oil source; 24. Back pressure valve; 25. Bypass check valve; 26. Safety valve; 27. Air inlet; 28. Pulse control chamber; 29. ​​Centering bearing; 30. Thrust bearing; 31. Anti-friction groove; 32. Dynamic sealing structure; 33. Laval throat; 34. Third fluid channel; 35. Diaphragm. Detailed Implementation

[0037] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0039] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship 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 utility model.

[0040] In this application, unless otherwise expressly 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 communication connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "a particular embodiment," "example," or "specific example," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0042] Example 1

[0043] like Figure 1 As shown, this application relates to a sound velocity measuring device in a medium-high pressure hydraulic pipeline, including a drive shaft, a rotary valve 2, a transition end cap, a hydraulic pipeline, a first fiber Bragg grating sensor 5, and a second fiber Bragg grating sensor 6; the axial output port of the rotary valve 2 is connected to the transition end cap, and the transition end cap is connected to the hydraulic pipeline; the front end of the hydraulic pipeline is connected to the first fiber Bragg grating sensor 5, and the rear end is connected to the second fiber Bragg grating sensor 6; the rotary valve 2 includes a valve cover 21, a valve body 22, a rotary valve core 23 disposed in the valve body 22, and a bearing; the drive shaft is connected to the rotary valve core 23, and the rotary valve core 23 has a separate burst chamber and a low-pressure chamber 8; the burst chamber has a first conical nozzle 9, and the low-pressure chamber 8 has a second conical nozzle 10; the axial output port of the rotary valve 2 has a third conical nozzle 11; the transition end cap has a fourth conical nozzle 12;

[0044] The rotary valve 2 is configured to: control the rotary valve core 23 to rotate via the rotation of the drive shaft, thereby forming a Laval tube 13 with the first conical nozzle 9 and the third conical nozzle 11, and forming a spindle-shaped pulse-controlling chamber 28 with the third conical nozzle 11 and the fourth conical nozzle 12. The fourth conical nozzle 12 is connected to the hydraulic pipeline, and the pulse-controlling chamber 28 contains hydraulic oil from the hydraulic pipeline. When the hydraulic oil in the burst chamber is injected into the pulse-controlling chamber 28, it pushes the hydraulic oil in the pulse-controlling chamber 28 through the fourth conical nozzle 12 into the hydraulic pipeline to form an impact pulsating flow, presenting the state of the rotary valve 2 outputting pulsating flow to the hydraulic pipeline; or, the second conical nozzle 10 and the third conical nozzle 11 form a Laval tube 13 to recover the pulsating flow of the hydraulic pipeline into the low-pressure chamber 8 through the fourth conical nozzle 12 and the Laval tube 13; or, the third conical nozzle 11 is closed in a closed state between the two states.

[0045] The hydraulic oil pressure, hydraulic pulse amplitude, and number of pulses in the hydraulic pipeline are scanned, measured, and recorded by the first fiber optic grating sensor 5 and the second fiber optic grating sensor 6, so as to realize the measurement of the propagation speed of sound in the hydraulic oil under a certain pressure.

[0046] The aforementioned closed state specifically refers to the situation where, between the injection state and the recovery state of the rotary valve 2, the rotary valve core 23 closes the third conical nozzle 11 at the front end of the hydraulic pipeline, thus completing the complete closure of the front end of the hydraulic pipeline and achieving complete reflection of the pulsating impact flow that oscillates back and forth within the pipeline at the front end.

[0047] By setting up the burst chamber 7 and the low-pressure chamber 8, the connection between the burst chamber 7 and the low-pressure chamber 8 and the hydraulic pipeline 4 can be switched, thereby realizing three working states of the rotary valve 2. The three working states are: when the hydraulic oil in the burst chamber 7 is injected into the pulse control chamber, the rotary valve 2 outputs a pulsating flow to the hydraulic pipeline 4; the second conical nozzle 10 is connected to the third conical nozzle 11 to recover the pulsating flow of the hydraulic pipeline 4 into the low-pressure chamber 8; or the third conical nozzle 11 is closed, which is between the two states. Through the programming control of the conversion of the three working states, a relatively single pulsating impact is generated in the closed pipeline to form a back-and-forth reflecting oscillating attenuated wave. Furthermore, the hydraulic oil pressure, hydraulic pulse amplitude and number are scanned, measured and recorded by the first fiber optic grating sensor 5 and the second fiber optic grating sensor 6 at both ends of the closed pipeline, thereby further realizing the measurement of the propagation speed of the sound in the hydraulic oil in the hydraulic pipeline 4 under a certain pressure. On the other hand, the hydraulic line 4 can be alternately connected through the burst chamber 7 and the low-pressure chamber 8, so that the pressure of the hydraulic line 4 can be "artificially" controlled by the outside to insert a pressure indicator for calculating the cycle time, which brings convenience to the measurement of time or period.

[0048] Specifically, a transition valve cover 23 is also connected to the outside of the valve body.

[0049] Specifically, the fiber Bragg grating sensor may include a Bragg grating or a chirped grating, preferably a chirped grating.

[0050] In a preferred embodiment, the rotary valve core 23 is further provided with a first fluid channel 14 communicating with the burst chamber and a second fluid channel 15 communicating with the low-pressure chamber 8; the valve body 22 is provided with a first flow channel 16 communicating with the first fluid channel 14 along the circumferential direction, so that the hydraulic oil source 20 with a pressure greater than that of the constant pressure oil source 19 enters the burst chamber through the first flow channel 16 and the first fluid channel 14; the valve body 22 is also provided with a second flow channel 17 communicating with the second fluid channel 15 along the circumferential direction, so that the hydraulic oil in the low-pressure chamber flows back to the oil tank 18 through the second fluid channel 15 and the second flow channel 17.

[0051] Specifically, the pressure value of the hydraulic oil source 20 should be much greater than the pressure value of the constant pressure oil source 19, preferably 30 MPa, and the pressure value of the constant pressure oil source 19 should be greater than 10 MPa to ensure the relatively constant elastic modulus of the oil, preferably set to 20 MPa. In order to maintain the constant pressure of the constant pressure oil source, a weighted accumulator is preferred to maintain the pressure. The oil tank 18 is an open oil tank that is open to the atmosphere and can be equipped with an air filter.

[0052] Through the above implementation scheme, the rotary valve core 23 is provided with a first fluid channel 14 and a second fluid channel 15, and the valve body 22 is provided with a first flow channel 16 and a second flow channel 17. The first flow channel 16 is used to form an input channel with the first fluid channel 14, which can continuously input the hydraulic oil source of the external constant pressure oil source 19 into the explosion chamber, ensuring the timeliness of the filling of "ammunition" in the explosion chamber 7 and the stability of the pressure energy, providing a new way to prepare single or continuous pulse impacts;

[0053] The second flow channel 17 is used to form an output channel with the second fluid channel 15. It can output the hydraulic oil after the low-pressure chamber 8 is connected to the hydraulic pipeline 4 through the output channel back to the oil tank 18. This can eliminate free air bubbles in the hydraulic oil of the hydraulic pipeline 4, and rapidly reduce the pulsation of the hydraulic oil in the hydraulic pipeline 4, or ensure the effect of the "ammunition" in the explosion chamber 7 on the hydraulic oil pressure increase of the hydraulic pipeline 4 by the oil flowing back to the oil tank 18, thereby achieving the stability or constant pressure in the hydraulic pipeline.

[0054] In a preferred embodiment, a check valve 25 is provided in the first fluid channel 14 to prevent the hydraulic oil in the explosion chamber from flowing back to the hydraulic oil source 20 when it is impacted. During the rotation of the rotary valve, the explosion chamber always receives the replenishment or supply of high-pressure oil from the hydraulic oil source 20 through the check valve 25, ensuring the pressure stability of the hydraulic oil source 20 and the energy concentration of the energy group delivered to the hydraulic pipeline 4 through the explosion chamber 7, without bypass overflow. By setting a back pressure valve 24, the oil in the low-pressure chamber 8 has a certain back pressure. This back pressure, on the one hand, prevents the oil flowing back to the oil tank 18 through the low-pressure chamber 4 from flowing too fast and generating air bubbles, and on the other hand, ensures that the oil in the low-pressure chamber 8 can provide lubrication for the bearing.

[0055] In a preferred embodiment, the interior of the explosive chamber 7 is divided into a gas chamber 71 and a liquid chamber 72 by a diaphragm 35. The gas chamber 71 is filled with high-pressure gas, and the hydraulic oil in the liquid chamber 72 is supplied through the first flow channel 14 and the first fluid channel 14. The rotary valve core 23 has an air inlet 27 that communicates with the gas chamber 72, so that the pressure or volume of the gas in the gas chamber 71 can be easily controlled through the air inlet 27. The gas filling the gas chamber 71 can effectively utilize the characteristic that the compression ratio of gas is greater than that of oil to ensure that the explosive chamber delivers a sufficient volume of energy to the hydraulic pipeline 4.

[0056] Furthermore, the inner wall of the gas chamber 71 of the explosive chamber 7 is formed with an arc surface, and the inner wall of the liquid chamber 7 is formed with a first conical surface and a second conical surface connected along the axial direction. The first conical surface is connected to the arc surface, and the inner diameter of the explosive chamber 7 gradually decreases from the first conical surface to the second conical surface.

[0057] In a preferred embodiment, a blind hole is provided at the end of the hydraulic line 4, and a second fiber optic grating sensor 6 is installed inside the blind hole. A bypass check valve 25 is provided at the end of the blind hole. The bypass check valve 25 allows the external constant pressure oil source 19 to supply hydraulic oil to the hydraulic line. This allows air in the hydraulic line 4 to be discharged from the open oil tank 18 through the pulse control chamber 28, low pressure chamber 8, and back pressure valve 24 when the rotary valve is rotated to the recovery state. This achieves the purpose of removing air bubbles and flushing, ensuring that the hydraulic oil in the hydraulic line 4 is free of air bubbles and maintains a relatively constant pressure, which is greater than the opening pressure of the back pressure valve 24. On the other hand, when the front end of the hydraulic line 4 is closed, the bypass check valve 25 can provide a stable and constant pressure to the hydraulic oil in the hydraulic line 4, ensuring that the hydraulic oil in the hydraulic line 4 will not backflow or contaminate the constant pressure oil source through the bypass check valve 25.

[0058] When the hydraulic oil in the hydraulic line 4 is impacted, the bypass check valve 25 can prevent the oil from flowing back to the constant pressure oil source 19. When the rotary valve is in the closed state, it ensures that the front end of the hydraulic line 4 is closed, so that the oil in the hydraulic line 4 maintains constant pressure and does not flow. This can dissolve and eliminate residual air bubbles in the hydraulic oil in the hydraulic line 4, and can also maintain the constant oil pressure and elastic modulus in the hydraulic line 4 by standing for a long time.

[0059] In a preferred embodiment, at least two sets of centering bearings 29 are connected to the outer periphery of the rotary valve core 23 along the axial direction to support the rotation of the rotary valve core 23; at least two sets of thrust bearings 30 are respectively provided at both ends of the rotary valve core 23; the thrust bearing 30 at the valve cover end pushes the rotary valve core 23 through the valve cover 21 to ensure that the dynamic and static sealing rings between the rotary valve core 23 and the inner end face of the valve body 22 are in tight contact; the thrust bearing 30 connected to the inner end face of the valve body 22 is used to ensure that there is sufficient clearance between the rotary valve core 23 and the inner end face of the valve body 22 to reduce friction; a friction-reducing groove 31 is opened on the circumference of the rotary valve core 23, and the friction-reducing groove 31 is connected to the low-pressure chamber 8 through a third fluid channel 34, so that there is a certain pressure of pressure oil in the friction-reducing groove 31, so that the rotary valve core 23 can be suspended in the circumferential hole of the valve body 22 with the assistance of pressure oil, and leaks to the centering bearing 29 and thrust bearing 30 supporting the rotation of the rotary valve core 23 to provide lubrication for the bearings.

[0060] Specifically, the pair of dynamic sealing structures 32 between the first flow channel 16 and the second flow channel 17 can be combined into one, thus requiring at least three sets of dynamic and static ring sealing structures. These sealing structures ensure that the oil between the first flow channel 16 and the second flow channel 17 of the rotary valve core 23 does not interfere with each other, and prevents high pressure from filling into low pressure and low pressure from sucking in high pressure. In order to ensure the high-speed rotation of the rotary valve core 23, the anti-friction groove 31 is connected to the oil with a certain back pressure in the low-pressure chamber 8 through the throttling hole, ensuring that the rotary valve core 23 is suspended in the circumferential hole of the valve body 22 with the assistance of pressurized oil, assisting the axial centering bearing 29 in providing auxiliary support, and can further leak to the centering bearing 29 and thrust bearing 30 that support the rotation of the rotary valve core 23, providing lubrication for the bearings; the thrust bearings 30 at both ends of the rotary valve core 23 can press the rotary valve core 23 tightly against the injection outlet through the valve cover 21.

[0061] In a preferred embodiment, at least two sets of dynamic sealing structures 32 are spaced radially between the coaxial annular surfaces of the rotary valve core 23 and the valve body 22. The rotary annular surface where the third conical nozzle 11 is located is positioned between the two sets of dynamic sealing structures 32 to ensure that the oil in the third conical nozzle 11 is not disturbed by external oil. Dynamic sealing structures 32 are spaced axially between the circumferential surfaces of the rotary valve core 23 and the valve body 22. There are at least two pairs of dynamic sealing structures 32 on both sides of the first flow channel 16. There are at least two pairs of dynamic sealing structures 32 on both sides of the second flow channel 17.

[0062] Specifically, a plurality of dynamic sealing structures 32 are provided between the rotary valve core 23 and the valve body 22; the dynamic sealing structure 32 includes a dynamic ring and a stationary ring, the dynamic ring is provided on the rotary valve core 23 and the stationary ring is provided on the valve body 22; the rotating ring surface where the third conical nozzle 11 is located is provided between the two sets of dynamic sealing structures 32, especially when the rotary valve core 23 connects the third conical nozzle 11 to the low-pressure chamber 8, it ensures that the third conical nozzle 11 is not interfered with by external high-pressure oil.

[0063] The dynamic seal structure 32 achieves axial end-face sealing through the fluid pressure and spring pressure of the compensation mechanism on both the stationary and dynamic ring end faces, thereby preventing fluid leakage. Mechanical seals mainly consist of a stationary ring, a rotating ring, an elastic element, a spring seat, a set screw, a rotating ring auxiliary sealing ring, and a stationary ring auxiliary sealing ring. The end faces of the dynamic and stationary rings are perpendicular to the axis of rotation. The spring force presses the dynamic ring tightly against the stationary ring, forming a seal. The end-face materials of the dynamic and stationary rings typically have good wear resistance and thermal conductivity to reduce friction and facilitate heat transfer. They offer advantages such as reliable sealing performance, low leakage, long service life, low power loss, and wide applicability, making them particularly suitable for high-speed, high-pressure differential operating conditions and highly corrosive process media.

[0064] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0065] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0066] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A device for measuring the velocity of sound in a medium- or high-pressure hydraulic pipeline, characterized in that, The system includes a drive shaft, a rotary valve, a transition end cap, hydraulic lines, a first fiber Bragg grating sensor, and a second fiber Bragg grating sensor. The axial output port of the rotary valve is connected to the transition end cap, which is connected to the hydraulic lines. The front end of the hydraulic lines is connected to the first fiber Bragg grating sensor, and the rear end is connected to the second fiber Bragg grating sensor. The rotary valve includes a valve cover, a valve body, a rotary valve core housed within the valve body, and a bearing. The drive shaft is connected to the rotary valve core, which contains isolated burst chambers and low-pressure chambers. The burst chamber has a first conical nozzle, and the low-pressure chamber has a second conical nozzle. The axial output port of the rotary valve has a third conical nozzle, and the transition end cap has a fourth conical nozzle. The rotary valve is configured to: control the rotation of the rotary valve core via the rotation of the drive shaft, thereby forming a Laval tube with the first and third conical nozzles, and a spindle-shaped pulse-controlling chamber with the third and fourth conical nozzles. The fourth conical nozzle is connected to the hydraulic pipeline, and the pulse-controlling chamber contains hydraulic oil from the hydraulic pipeline. When the hydraulic oil in the burst chamber is injected into the pulse-controlling chamber, it pushes the hydraulic oil in the pulse-controlling chamber through the fourth conical nozzle into the hydraulic pipeline to form an impact pulsating flow, presenting an injection state where the rotary valve outputs pulsating flow to the hydraulic pipeline; or, the second and third conical nozzles form a Laval tube to allow the pulsating flow from the hydraulic pipeline to enter the low-pressure chamber after passing through the spindle-shaped pulse-eliminating chamber formed by the fourth and third conical nozzles, presenting a recovery state where the pulsating flow enters the low-pressure chamber; or, a closed state where the third conical nozzle is closed, which is between the two states. The hydraulic oil pressure, hydraulic pulse amplitude, and number of pulses in the hydraulic pipeline are scanned, measured, and recorded by the first fiber optic grating sensor and the second fiber optic grating sensor, so as to realize the measurement of the propagation speed of sound in the hydraulic oil in the hydraulic pipeline under a certain pressure.

2. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 1, characterized in that, The rotary valve core is also provided with a first fluid channel communicating with the bursting chamber and a second fluid channel communicating with the low-pressure chamber. The valve body has a first flow channel connected to the first fluid channel along its circumference, so that hydraulic oil with a pressure greater than that of the constant pressure oil source enters the burst chamber through the first flow channel; the valve body also has a second flow channel connected to the second fluid channel along its circumference, so that hydraulic oil in the low pressure chamber flows back to the oil tank through the second fluid channel.

3. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 2, characterized in that, A one-way valve is installed in the first fluid channel so that the hydraulic oil in the explosion chamber does not flow back to the hydraulic oil source when the hydraulic oil in the explosion chamber is impacted. During the rotation of the rotary valve, the explosion chamber always receives the replenishment or supply of high-pressure oil from the hydraulic oil source through the one-way valve. The second flow channel is equipped with a back pressure valve that connects the low-pressure chamber to the second flow channel, so as to ensure that the oil flowing back to the oil tank through the back pressure valve has a certain back pressure in the low-pressure chamber.

4. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 3, characterized in that, The explosive chamber is connected to a diaphragm that divides the explosive chamber into a gas chamber and a liquid chamber, and a rotary valve core. An air inlet is provided that communicates with the air chamber.

5. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 4, characterized in that, The inner wall of the gas chamber of the explosive chamber is formed with an arc surface on one side, and the inner wall of the liquid chamber of the explosive chamber has a first conical surface and a second conical surface connected along the axial direction. The first conical surface is connected to the arc surface, and the inner diameter of the explosive chamber gradually decreases from the first conical surface to the second conical surface.

6. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 3, characterized in that, A blind hole is provided at the end of the hydraulic pipeline, and a second fiber optic grating sensor is installed inside the blind hole. An external constant pressure oil source supplies hydraulic oil to the hydraulic pipeline through a bypass check valve at the blind end of the hydraulic pipeline. When the air that needs to be discharged from the hydraulic pipeline is rotated to the recovery state by the rotary valve, it passes through the pulse control chamber, low pressure chamber, second fluid channel, back pressure valve, and second flow channel, and then is discharged from the open oil tank.

7. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 1, characterized in that, At least two sets of centering bearings are connected to the outer periphery of the rotary valve core along the axial direction to support the rotation of the rotary valve core; At least two sets of thrust bearings are provided at both ends of the rotary valve core. The thrust bearing at the valve cover end pushes the rotary valve core through the valve cover to ensure that the dynamic and static sealing rings between the rotary valve core and the inner end face of the valve body are in tight contact. The thrust bearing connected to the inner end face of the valve body is used to ensure that there is sufficient clearance between the rotary valve core and the inner end face of the valve body to reduce friction.

8. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 7, characterized in that, The rotary valve core has anti-friction grooves on its circumference. The anti-friction grooves are connected to the low-pressure chamber through a third fluid channel, so that there is a certain pressure of oil in the anti-friction grooves. This allows the rotary valve core to be suspended in the circumferential hole of the valve body with the help of the pressure oil, and to leak into the centering bearing and thrust bearing that support the rotation of the rotary valve core, so as to provide lubrication for the bearings.

9. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 7, characterized in that, At least two sets of dynamic sealing structures are spaced radially between the coaxial annular surfaces of the rotary valve core and the valve body. The rotary annular surface where the third conical nozzle is located is positioned between the two sets of dynamic sealing structures to ensure that the oil in the third conical nozzle is not disturbed by external oil.

10. The sound velocity measuring device in a medium- or high-pressure hydraulic pipeline as described in claim 9, characterized in that, A dynamic sealing structure is provided at intervals along the axial direction between the rotary valve core and the circumferential surface of the valve body; there are at least two pairs of dynamic sealing structures on both sides of the first flow channel; and at least two pairs of dynamic sealing structures on both sides of the second flow channel.

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