A cavitation risk prediction and active avoidance control method for a high-pressure control valve

Abstract

The application provides a cavitation risk prediction and active avoidance control method for a high-pressure regulating valve, which comprises the following steps: determining whether cavitation occurs in the high-pressure regulating valve at present; when cavitation is determined to occur, recording the real-time opening degree and real-time pressure difference of the high-pressure regulating valve at present, and dynamically constructing or updating a cavitation forbidden zone mapping table, wherein the cavitation forbidden zone mapping table records the opening degree interval determined to cause cavitation under different pressure differences; when a target opening degree instruction is received from an external control system, the target opening degree instruction is intercepted and compared with the cavitation forbidden zone mapping table, and if the target opening degree indicated by the target opening degree instruction falls into the cavitation forbidden zone, corresponding opening degree avoidance control steps are performed according to the control mode of the external control system. The application realizes instant prediction, real-time interception and dynamic avoidance of the cavitation risk of the high-pressure regulating valve.

Description

Technical Field

[0001] This invention relates to a control method for a high-pressure regulating valve, specifically a method for predicting and actively avoiding cavitation risks in a high-pressure regulating valve, belonging to the field of valve servo control technology. Background Technology

[0002] In high-pressure differential applications, when the control valve operates at a small opening, the flow velocity at its throttling section is extremely high, causing a sharp drop in local static pressure. When this static pressure falls below the saturated vapor pressure of the fluid medium, the fluid undergoes a phase change and generates a large number of microbubbles. As the fluid flows out of the throttling zone, the static pressure rapidly recovers due to the increased cross-sectional area of ​​the channel. These bubbles collapse instantaneously within a very short time, generating ultra-high-speed microjet streams directed towards the metal surfaces of the valve body and valve core, as well as extremely high-pressure shock waves, i.e., cavitation occurs.

[0003] Currently, the industry's methods for addressing cavitation damage in high-pressure regulating valves are relatively limited, mainly facing the following problems: Traditional anti-cavitation methods primarily rely on mechanical structure design or material surface modification. These methods are not only costly to manufacture, but under extreme operating conditions, the metal surface can still be rapidly eroded, resulting in honeycomb-like spalling, causing internal leakage, jamming, or even complete valve failure. Passive defense is costly and prone to failure. Existing cavitation monitoring technologies mainly use external sensors for open-loop vibration diagnosis, which can only be used for post-event alarms or predictive maintenance. They cannot input early diagnosis results of cavitation occurrence into the bottom-level opening positioning control closed loop in real time, lacking online real-time intelligent intervention and avoidance methods, leading to a disconnect between monitoring and control.

[0004] Therefore, how to deeply integrate the high-sensitivity, low-latency cavitation prediction mechanism with the underlying servo control logic of the control valve, so as to realize the transformation of the cavitation risk handling of high-pressure control valves from passive acceptance to active dynamic avoidance, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] Based on the above background, the purpose of this invention is to provide a method for predicting and actively avoiding cavitation risks in high-pressure regulating valves. This method does not require changing the physical structure of the regulating valve, but rather achieves proactive elimination and decentralized protection of cavitation risks in high-pressure regulating valves by pre-intercepting and avoiding target opening commands.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve, the method comprising the following steps:

[0008] The high-frequency transient dynamic signal of the high-pressure regulating valve during operation is collected, and the high-frequency transient dynamic signal is transformed in the frequency domain to extract the characteristic energy value of the characteristic frequency band. Based on the characteristic energy value, it is determined whether the high-pressure regulating valve is currently experiencing cavitation.

[0009] When cavitation is determined to occur, the current real-time opening degree and real-time pressure difference of the high-pressure regulating valve are recorded, and a cavitation forbidden zone mapping table is dynamically constructed or updated. The cavitation forbidden zone mapping table records the opening degree ranges at different pressure differences that indicate cavitation has occurred. The opening degree range is defined as the cavitation forbidden zone.

[0010] Upon receiving a target opening instruction from an external control system, the instruction is intercepted and compared with the cavitation exclusion zone mapping table. If the target opening indicated by the instruction falls within the cavitation exclusion zone, the corresponding opening avoidance control steps are executed according to the control mode of the external control system.

[0011] Preferably, the acquisition step of the high-frequency transient dynamic signal is as follows: on the flow channel outlet side of the high-pressure regulating valve, the high-frequency transient dynamic signal inside the valve body of the high-pressure regulating valve is exported to the normal temperature range through a high waveguide rod and then acquired.

[0012] Preferably, determining whether the high-pressure regulating valve is currently experiencing cavitation includes the following steps:

[0013] The high-frequency transient dynamic signal is subjected to a fast Fourier transform to calculate the ratio of the characteristic energy value of the characteristic frequency band to the total energy of the entire frequency band, thereby obtaining the normalized relative energy value, wherein the characteristic frequency band is 5-20kHz;

[0014] If both the normalized relative energy value and the characteristic energy value continuously exceed their respective set thresholds within a set time window, it is determined that cavitation has occurred.

[0015] As a preferred method, dynamically updating the cavitation exclusion zone mapping table specifically includes the following steps:

[0016] Based on real-time differential pressure and real-time medium temperature, the boundary of the cavitation exclusion zone is dynamically corrected online so that the cavitation exclusion zone is dynamically updated according to the fluctuation of the process conditions of the high-pressure regulating valve.

[0017] Preferably, the opening avoidance control step includes: if the external control system does not activate the forced follow mode, then refusing to control the opening of the high-pressure regulating valve to remain within the cavitation exclusion zone, controlling the opening of the high-pressure regulating valve to move to a safe position at the edge of the cavitation exclusion zone, and sending a cavitation avoidance offset signal to the external control system, so that the external control system adjusts the opening of the bypass valve connected in parallel with the high-pressure regulating valve according to the cavitation avoidance offset signal, in order to compensate for the flow deviation caused by the high-pressure regulating valve deviating from the target opening.

[0018] Preferably, when controlling the opening of the high-pressure regulating valve to move to a safe position at the edge of the cavitation exclusion zone, an S-shaped velocity curve is used to limit the acceleration of the valve stem of the high-pressure regulating valve, so as to smoothly adjust the opening of the high-pressure regulating valve and eliminate water hammer in the pipeline.

[0019] Preferably, the opening avoidance control step further includes: if the external control system is in forced following mode, a continuous micro-oscillation signal is superimposed on the target opening as the final control input, controlling the valve core of the high-pressure regulating valve to perform a small dynamic reciprocating motion near the target opening, so as to disperse the concentrated impact of the bubble collapse microjet on the throttling surface of the valve core.

[0020] Preferably, the control step for the oscillation frequency of the superimposed continuous micro-oscillation signal is as follows: pseudo-random frequency modulation is used to control the oscillation frequency of the continuous micro-oscillation signal to dynamically drift within a set frequency range, so as to avoid resonance of the high-pressure regulating valve and connecting pipeline.

[0021] Preferably, the control step for the oscillation frequency of the superimposed continuous micro-oscillation signal is as follows: the amplitude of the continuous micro-oscillation signal is controlled to be positively correlated with the extracted characteristic energy value, and the amplitude of the continuous micro-oscillation signal is limited to not exceed the set upper limit amplitude, so as to disperse the concentrated impact while limiting the wear of the valve stem packing of the high-pressure regulating valve.

[0022] Preferably, when it is determined that the current cavitation state has disappeared, the continuous micro-oscillation signal superimposed on the target opening is stopped, and the opening of the high-pressure regulating valve is controlled to smoothly recover and stabilize at the target opening.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] This invention discloses a method for predicting and actively avoiding cavitation risks in high-pressure regulating valves. By deeply integrating high-frequency transient signal feature extraction with a dual-mode valve opening servo algorithm, it achieves real-time prediction, interception, and dynamic avoidance of cavitation risks in high-pressure regulating valves without altering their physical structure. By constructing an online dynamic exclusion zone mapping based on temperature and pressure, the cavitation exclusion zone can dynamically avoid complex process fluctuations in the field. Through a micro-motion dispersion anti-cavitation mechanism, the localized destructive energy of the bubble collapse microjets is uniformly dispersed. Combined with pseudo-random frequency modulation and characteristic energy feedback amplitude, it achieves coordinated control of cavitation protection and packing mechanical wear life, demonstrating significant industrial application value. Attached Figure Description

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

[0026] Figure 1 This is a schematic diagram of the system architecture and method flow of the cavitation risk prediction and active avoidance control method for high-pressure regulating valves provided in the embodiments of the present invention;

[0027] Figure 2 This is a schematic diagram of the pseudo-random high-frequency micro-motion oscillation dispersion protection principle provided by an embodiment of the present invention under forced following mode;

[0028] In the diagram: 10. High-pressure regulating valve; 11. Valve body; 12. Valve core; 13. Valve stem; 14. Throttling orifice; 20. High-pressure waveguide rod; 30. High-frequency dynamic sensor; 40. Edge computing module; 50. External control system; 60. Bypass valve; 71. Inlet pressure sensor; 72. Outlet pressure sensor; 73. Temperature sensor. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0030] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0031] like Figure 1 As shown, an embodiment of the present invention discloses a method for predicting and actively avoiding cavitation risks in a high-pressure regulating valve. This method relies on a closed-loop control system consisting of a high-pressure regulating valve 10, an external control system 50, a bypass valve 60, an edge computing module 40, and a high-frequency dynamic sensor 30. The valve body 11 of the high-pressure regulating valve 10 contains a valve core 12 and a valve stem 13, with the valve stem 13 passing through valve stem packing and connected to an external actuator. Under high pressure differential conditions, when fluid flows through the throttling orifice 14 of the valve core 12, a throttling effect occurs, causing a sharp drop in local static pressure. The bypass valve 60 is installed in parallel on the bypass pipeline of the high-pressure regulating valve 10, sharing the task of regulating the pipeline flow with the high-pressure regulating valve 10.

[0032] High-throughput high-frequency transient dynamic signals are first acquired and exported via a high-guide waveguide 20 installed on the outlet side of the high-pressure regulating valve 10. Rigid mounting holes are provided on the wall of the valve body 11 corresponding to the dense bubble collapse area. One end of the high-guide waveguide 20 is securely mounted to the inner wall of the valve body 11, while the other end extends radially outward, passing through the insulation layer of the piping system and exiting to the ambient temperature zone. The high-guide waveguide 20 can be made of 316L stainless steel or titanium alloy, and its surface undergoes a high-gloss finish machining process. When broadband acoustic emission signals and high-frequency mechanical vibrations are generated inside the valve body 11 due to bubble collapse, these high-frequency transient dynamic signals undergo near-lossless total internal reflection transmission within the high-guide waveguide 20, thus being safely guided to the high-frequency dynamic sensor 30 located in the ambient temperature zone. The high-frequency dynamic sensor 30 can specifically be a piezoelectric accelerometer or an acoustic emission probe, which transmits the acquired time-domain analog signals to the edge computing module 40 after high-speed analog-to-digital conversion.

[0033] After the high-frequency dynamics sensor 30 transmits the acquired time-domain signal to the edge computing module 40, the edge computing module 40 first performs a fast Fourier transform on the high-frequency transient dynamics signal acquired by high-speed analog-to-digital sampling to obtain the power spectrum distribution across the entire frequency band. Based on this, the edge computing module 40 calculates the energy integral value within the characteristic frequency band. This characteristic frequency band is defined as the 5-20kHz ultrasonic high-frequency band, which is the concentrated distribution area of ​​acoustic emission and micro-vibration characteristic energy generated during bubble collapse, while ordinary pipeline valve mechanical vibration and friction noise are mainly concentrated in the low-frequency band below 1kHz. The characteristic energy value is calculated using the following formula:

[0034] ;

[0035] in, Represents the power spectral density function. This indicates the frequency. Simultaneously, the edge computing module 40 calculates the total power spectral energy value across the entire signal frequency band. This full-band coverage spans from 0 to 50 kHz to ensure the integrity of the normalized substrate. Subsequently, the edge computing module 40 calculates the normalized relative energy value. The calculation formula is:

[0036] ;

[0037] This normalization process ensures that the judgment result is unaffected by random changes in the overall signal strength caused by operating condition fluctuations. After completing the energy calculation, the edge computing module 40 performs a dual-threshold delay judgment. Specifically, a normalized relative energy threshold is set. and the absolute threshold of characteristic energy Within the preset time window For example, within 500ms, the system must simultaneously and continuously satisfy the following two equations:

[0038] ;

[0039] Only when both of the above conditions are simultaneously and continuously met within the same time window will the edge computing module 40 determine that the high-pressure regulating valve 10 has experienced actual cavitation. If only one condition is met or the signal manifests as a transient pulse, it is determined to be a pseudo-cavitation interference signal generated by mechanical friction between the valve stem 13 and the valve stem packing, contact friction between the valve core 12 and the valve seat, or occasional mechanical impact. By setting the ratio of characteristic frequency band energy to full frequency band energy and combining it with continuous verification of the absolute value of characteristic energy within a time window, the high-frequency transient characteristics generated by bubble collapse can be fundamentally distinguished from the low-frequency mechanical vibration and friction noise commonly found in pipeline systems, thereby improving the confidence and real-time performance of cavitation risk prediction.

[0040] When the edge computing module 40 determines that cavitation has occurred, the system immediately records the current real-time opening degree of the high-pressure regulating valve 10. and real-time differential pressure The real-time pressure difference The pressure difference is obtained by detecting the pressure before and after the valve from the upstream pressure sensor 71 and the downstream pressure sensor 72, respectively. Based on the recorded values, the edge computing module 40 dynamically constructs or updates the cavitation exclusion zone mapping table in non-volatile memory. For this specific pressure difference... The system will open the interval The area is marked as a cavitation exclusion zone, and its boundary values ​​are determined according to the following formula:

[0041] ;

[0042] in, For a preset safety margin, for example, an opening unit of 0.5% or 1% can be used. Since the saturated vapor pressure of the medium varies with the medium temperature... The pressure changes significantly due to fluctuations, and the static pressure downstream of the valve is directly affected by the pressure difference. To mitigate the impact of cavitation exclusion zones on process conditions and enable adaptive drift, the edge computing module 40 further utilizes a thermodynamic coupling correction model to dynamically correct the exclusion zone boundary online. Temperature Temperature data is collected in real time by temperature sensor 73 installed on the flow channel. The corrected boundary formula is:

[0043] ;

[0044] in, This is a pressure difference correction factor; the larger the pressure difference, the wider the range of openings where flashing and cavitation occur. This is a temperature correction factor. The higher the temperature, the greater the saturated vapor pressure of the medium, and the stronger the cavitation tendency. Through dynamic temperature and pressure correction, the boundaries in the cavitation exclusion zone mapping table are not factory-fixed parameters, but can drift in real time with pipeline process fluctuations. This provides an accurate and timely spatial decision-making basis for subsequent opening avoidance control, avoiding the loss of normal flow regulation capacity caused by an excessively wide exclusion zone, and the risk of protection failure caused by an excessively narrow exclusion zone.

[0045] When the external control system 50 sends a target opening command to the intelligent valve positioner or edge computing module 40 At that time, the edge computing module 40 intercepts the instruction at the front end and compares it in real time with the currently constructed cavitation exclusion zone mapping table. If the target opening instruction... The indicated target aperture falls within the revised cavitation exclusion zone. Within this range, the edge computing module 40 executes differentiated opening avoidance control steps based on the current control mode of the external control system 50.

[0046] If the external control system 50 does not activate the forced follow mode, the edge computing module 40 executes the normal mode avoidance strategy of branch A. In this case, the edge computing module 40 refuses to control the opening of the high-pressure regulating valve 10 to remain within the cavitation exclusion zone, and instead forcibly modifies the actual target opening to a safe opening position at the outer edge of the cavitation exclusion zone. Safe opening position The determination logic is as follows:

[0047] ;

[0048] in, To prevent the actuator from experiencing a dead zone of oscillation near the restricted area boundary, the valve stem 13 of the high-pressure regulating valve 10 drives the valve core 12 to the safe opening position. During the movement, the edge computing module 40 uses an S-shaped velocity curve to limit the acceleration and velocity of the valve stem 13. By controlling the third derivative of the valve stem 13 displacement, i.e., the jerk, the valve moves to the target safe position with a smooth and gradual acceleration curve. This smooth motion control effectively avoids the abrupt change in pipeline momentum caused by sudden changes in valve opening, thereby eliminating the occurrence of destructive water hammer in the pipeline. At the same time, the edge computing module 40 calculates the deviation of the valve opening from the target opening. The resulting flow deviation is recorded and transmitted back to the external control system 50 in real time as a cavitation avoidance offset signal. Upon receiving this cavitation avoidance offset signal, the external control system 50 proportionally adjusts the opening of the bypass valve 60 installed in parallel next to the high-pressure regulating valve 10. The bypass valve 60 then handles the fine-tuning flow that the high-pressure regulating valve 10 cannot provide due to the cavitation avoidance zone. As a result, the total flow rate of the pipeline network is kept constant, and the process maintains continuous and stable operation while the valve body actively avoids risks.

[0049] If the external control system 50 activates the forced follow mode, meaning the process does not allow for deviations in valve flow and opening, the high-pressure regulating valve 10 must be forced to maintain the target opening that was originally within the cavitation exclusion zone. At that point, the edge computing module 40 executes the forced follow mode avoidance strategy of branch B. For example... Figure 2 As shown, the edge computing module 40 at the target opening degree Superimposed continuous micro-oscillation signal As the final control input, control valve core 12 at the target opening degree. The flow field is constantly undergoing minute, dynamic reciprocating motions. From a local coordinate perspective, the formation and collapse of bubbles occur in a relatively fixed area relative to the throttling orifice 14. If the valve core 12 remains stationary, the tens of thousands of micro-jet streams generated by bubble collapse will continuously hammer the same point on the surface of the valve core 12, resulting in extremely rapid mechanical fatigue spalling. However, by superimposing continuous micro-oscillation signals, the flow field is always in a state of transient change. The micro-jet streams that were originally concentrated at a single coordinate point and collapsed are uniformly dispersed throughout the entire circumference of the throttling surface of the valve core 12, achieving spatial dispersion protection and effectively delaying the cumulative damage from cavitation erosion.

[0050] To avoid mechanical resonance between the continuous micro-oscillation signal and the valve stem 13 of the high-pressure regulating valve 10, the actuator, and even the entire connecting pipeline, the edge computing module 40 uses pseudo-random frequency modulation control to regulate the oscillation frequency of the continuous micro-oscillation signal. Specifically, the oscillation frequency continuously and irregularly drifts online within a preset frequency range, for example, this frequency range can be set to 0.5~1.5Hz. Through pseudo-random frequency modulation, the mechanical resonance conditions caused by continuous excitation at a single fixed frequency are eliminated, avoiding the risk of severe pipeline vibration and mechanical tearing, and ensuring the mechanical safety of the distributed protection mechanism.

[0051] Furthermore, frequent fretting accelerates the physical wear of the valve stem packing. To achieve a balance between mitigating cavitation impact and protecting the valve's mechanical lifespan, the edge computing module 40 controls the amplitude of the continuous fretting oscillation signal. Compared with the feature energy value obtained from real-time prediction Perform positive correlation dynamic matching, the specific relationship is as follows:

[0052] ;

[0053] in, This is a proportionality coefficient. When cavitation is mild, the fretting amplitude dynamically decreases, for example, it may only be ±0.1% of the opening. When cavitation is severe and the characteristic energy value is extremely high, the fretting amplitude dynamically increases to accelerate the dispersion of mechanical stress. Simultaneously, the system strictly limits the fretting amplitude to never exceed the set upper limit safety amplitude. For example, an opening of ±0.8% can prevent large fluctuations from causing flow control failure. Through this characteristic energy feedback-driven dynamic amplitude mechanism, a fine coordination is achieved between the cavitation protection strength and the valve mechanical wear rate, effectively dispersing the concentrated impact of bubble collapse while limiting unnecessary wear of the valve stem packing.

[0054] When the differential pressure at the pipeline front end decreases or the medium temperature drops, the edge computing module 40 detects that both the cavitation characteristic energy value and the relative energy value are lower than their respective judgment thresholds. When it determines that the cavitation state of the current high-pressure regulating valve 10 has completely disappeared, the edge computing module 40 smoothly and gradually attenuates the amplitude of the continuous micro-oscillation signal, causing it to gradually converge from the current value to zero. This stops the continuous micro-oscillation signal from being superimposed on the target opening, allowing the actual opening of the high-pressure regulating valve 10 to smoothly recover and stabilize at the target opening. .

[0055] As can be seen from the overall operation process described above, the steps disclosed in this invention constitute a deeply integrated linkage system. After the high-frequency transient dynamic signal is derived via the high-guide wave rod 20, it first achieves high-confidence real-time prediction of cavitation risk in the edge computing module 40 through frequency domain transformation and dual-threshold judgment. This prediction result then triggers the online construction of a dynamic restricted area mapping table and dynamic temperature and pressure correction, transforming the transient cavitation event into a queryable and driftable spatial restricted area. When the target opening command of the external control system 50 is intercepted in advance, the system makes intelligent decision-making branches between the normal mode and the forced following mode based on the current control mode. In the normal mode, active risk avoidance is achieved through S-curve smoothing and bypass flow compensation; in the forced following mode, physical distributed protection is achieved through pseudo-random high-frequency micro-motion. In this linkage system, the high sensitivity of cavitation prediction provides a trigger source for restricted area construction, the dynamic correction of the restricted area provides a spatial decision-making basis for opening avoidance, and the dual-mode avoidance control ultimately transforms the diagnostic results into substantial protective actions for the valve body.

[0056] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve, characterized in that: The method includes the following steps: The high-frequency transient dynamic signal of the high-pressure regulating valve during operation is collected, and the high-frequency transient dynamic signal is transformed in the frequency domain to extract the characteristic energy value of the characteristic frequency band. Based on the characteristic energy value, it is determined whether the high-pressure regulating valve is currently experiencing cavitation. When cavitation is determined to occur, the current real-time opening degree and real-time pressure difference of the high-pressure regulating valve are recorded, and a cavitation forbidden zone mapping table is dynamically constructed or updated. The cavitation forbidden zone mapping table records the opening degree ranges at different pressure differences that indicate cavitation has occurred. The opening degree range is defined as the cavitation forbidden zone. Upon receiving a target opening instruction from an external control system, the instruction is intercepted and compared with the cavitation exclusion zone mapping table. If the target opening indicated by the instruction falls within the cavitation exclusion zone, the corresponding opening avoidance control steps are executed according to the control mode of the external control system.

2. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 1, characterized in that: The specific steps for acquiring the high-frequency transient dynamic signal are as follows: on the outlet side of the flow channel of the high-pressure regulating valve, the high-frequency transient dynamic signal inside the valve body of the high-pressure regulating valve is exported to the normal temperature range through a high waveguide rod and then acquired.

3. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 1, characterized in that: Determining whether the high-pressure regulating valve is currently experiencing cavitation includes the following steps: The high-frequency transient dynamic signal is subjected to a fast Fourier transform to calculate the ratio of the characteristic energy value of the characteristic frequency band to the total energy of the entire frequency band, thereby obtaining the normalized relative energy value, wherein the characteristic frequency band is 5-20kHz; If both the normalized relative energy value and the characteristic energy value continuously exceed their respective set thresholds within a set time window, it is determined that cavitation has occurred.

4. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 1, characterized in that: Dynamically updating the cavitation exclusion zone mapping table includes the following steps: Based on real-time differential pressure and real-time medium temperature, the boundary of the cavitation exclusion zone is dynamically corrected online so that the cavitation exclusion zone is dynamically updated according to the fluctuation of the process conditions of the high-pressure regulating valve.

5. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 1, characterized in that: The opening avoidance control steps include: if the external control system does not activate the forced follow mode, it refuses to control the opening of the high-pressure regulating valve to remain within the cavitation exclusion zone, controls the opening of the high-pressure regulating valve to move to a safe position at the edge of the cavitation exclusion zone, and sends a cavitation avoidance offset signal to the external control system, so that the external control system adjusts the opening of the bypass valve connected in parallel with the high-pressure regulating valve according to the cavitation avoidance offset signal, in order to compensate for the flow deviation caused by the high-pressure regulating valve deviating from the target opening.

6. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 5, characterized in that: When controlling the opening of the high-pressure regulating valve to move to a safe position at the edge of the cavitation exclusion zone, an S-shaped velocity curve is used to limit the acceleration of the valve stem of the high-pressure regulating valve, so as to smoothly adjust the opening of the high-pressure regulating valve and eliminate water hammer in the pipeline.

7. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 1, characterized in that: The opening avoidance control step further includes: if the external control system is in forced following mode, a continuous micro-oscillation signal is superimposed on the target opening as the final control input, and the valve core of the high-pressure regulating valve is controlled to perform a small dynamic reciprocating motion near the target opening to disperse the concentrated impact of the bubble collapse microjet on the throttling surface of the valve core.

8. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 7, characterized in that: The control steps for the oscillation frequency of the superimposed continuous micro-oscillation signal are as follows: pseudo-random frequency modulation is used to control the oscillation frequency of the continuous micro-oscillation signal to dynamically drift within a set frequency range, so as to avoid resonance of the high-pressure regulating valve and connecting pipeline.

9. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 7, characterized in that: The control steps for the oscillation frequency of the superimposed continuous micro-oscillation signal are as follows: the amplitude of the continuous micro-oscillation signal is controlled to be positively correlated with the extracted characteristic energy value, and the amplitude of the continuous micro-oscillation signal is limited to not exceed the set upper limit amplitude, so as to disperse the concentrated impact while limiting the wear of the valve stem packing of the high-pressure regulating valve.

10. The method for predicting and actively avoiding cavitation risk in a high-pressure regulating valve according to claim 7, characterized in that: When it is determined that the current cavitation state has disappeared, the continuous micro-oscillation signal superimposed on the target opening is stopped, and the opening of the high-pressure regulating valve is controlled to smoothly recover and stabilize at the target opening.

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