A control method for preventing high-pressure liquid medium flashing in a hard-sealed ball valve and a hard-sealed ball valve

Abstract

This application provides a control method and a hard-seal ball valve for preventing flashing of high-pressure liquid media in a hard-seal ball valve. Belonging to the field of ball valve technology, the control method includes the following steps: selecting the saturated pressure-temperature curve corresponding to the actual high-pressure liquid medium; real-time acquisition of parameter sets, obtaining the corresponding saturated vapor pressure based on the valve inlet medium temperature, and determining whether flashing has occurred by comparing the valve outlet pressure and the saturated vapor pressure; if flashing has not occurred, determining the risk level using a flashing risk model and executing flashing suppression actions; if flashing has occurred, executing flashing protection actions; evaluating the control effect based on the parameter set, and dynamically optimizing the parameters for flashing suppression and flashing protection actions; this invention effectively solves the problem of flashing of high-pressure liquid media in hard-seal ball valves by accurately determining flashing based on medium characteristics and core parameters, and implementing flashing suppression and flashing protection respectively.

Description

Technical Field

[0001] This invention relates to the field of ball valve technology, specifically to a control method for preventing flash evaporation of high-pressure liquid media in a hard-seal ball valve and the hard-seal ball valve itself. Background Technology

[0002] Hard-seal ball valves are widely used in high-pressure liquid media transportation pipelines due to their excellent sealing performance, high pressure resistance, and wear resistance, undertaking the core functions of media on / off control and flow regulation. In actual operation, when a high-pressure liquid medium flows through the ball valve's throttling orifice, if the valve outlet pressure suddenly drops below the saturated vapor pressure corresponding to the current medium temperature, the liquid will undergo a phase change, generating a large number of bubbles. This phenomenon is called flash evaporation.

[0003] Flash evaporation poses significant risks to hard-seal ball valves and piping systems. When the bubbles generated by flash evaporation burst near the sealing surface, they release localized high temperatures and impact pressures, leading to rapid wear and peeling of the hard-seal surface and shortening the valve's sealing life. Uneven flow of the gas-liquid two-phase flow can cause severe valve vibration, and long-term effects can lead to loosening of valve body bolts, flange leakage, and even pipeline fatigue damage. Therefore, this is a problem that urgently needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a control method for preventing flash evaporation of high-pressure liquid media in a hard-seal ball valve and a hard-seal ball valve.

[0005] The technical solution adopted by this invention is as follows: Firstly, this application provides a control method for preventing flashing of high-pressure liquid media in a hard-seal ball valve, comprising the following steps:

[0006] Step S1: Based on the composition characteristics of the actual high-pressure liquid medium inside the hard-seal ball valve, select the corresponding saturation pressure-temperature curve;

[0007] Step S2: Real-time acquisition of parameter sets, which include at least valve inlet pressure, valve outlet pressure, and valve inlet medium temperature;

[0008] Step S3: Obtain the corresponding saturated vapor pressure based on the valve inlet medium temperature, and determine whether flash evaporation has occurred by comparing the valve outlet pressure with the saturated vapor pressure;

[0009] Step S4: If it is determined that flash evaporation has not occurred, the risk level is determined by the flash evaporation risk model, which includes high risk and low risk; if it is determined to be low risk, data collection is maintained; if it is determined to be high risk, flash evaporation suppression action is executed to prevent flash evaporation; if it is determined that flash evaporation has occurred, flash evaporation protection action is executed to reduce damage to the valve.

[0010] Step S5: Evaluate the control effect based on the parameter set, and dynamically optimize the parameters for flash evaporation suppression and flash evaporation protection.

[0011] In some embodiments, in step S1, the saturation pressure-temperature curve is determined as follows:

[0012] For single-component media, the Antoine equation is used to fit the curve;

[0013] For multi-component media, the mixed saturated vapor pressure is calculated by weighting the mole fraction of each component, and the corresponding curve of temperature versus mixed saturated vapor pressure is obtained by fitting.

[0014] In some embodiments, the parameter set further includes valve opening change rate and valve vibration acceleration;

[0015] The logic for determining whether flash evaporation has occurred in step S3 is as follows:

[0016] If the valve outlet pressure is less than the saturated vapor pressure, and the valve outlet pressure change rate is within a gradual range, or the valve vibration acceleration exhibits gas-liquid two-phase flow impact characteristics, then flash evaporation is determined to have occurred.

[0017] If the valve outlet pressure is greater than or equal to the saturated vapor pressure, and the valve inlet pressure and valve outlet pressure show the same trend, or the valve opening is in a stable adjustment state, then it is determined that flash evaporation has not occurred.

[0018] If none of the above conditions are met, it is determined to be an abnormal pressure fluctuation. The current state is maintained and the parameter acquisition frequency is increased.

[0019] In some embodiments, the flash evaporation risk model is established in step S4 as follows:

[0020] The core item is the ratio of the difference between the outlet pressure and the saturated vapor pressure to the saturated vapor pressure;

[0021] The first correction factor is positively correlated with the rate of change of valve opening; the faster the opening is adjusted, the larger the correction factor becomes.

[0022] The second correction factor is positively correlated with the pressure difference between the inlet and outlet; the larger the pressure difference, the larger the correction factor.

[0023] The risk value is the product of the core item and the first and second correction factors, and high and low risk levels are divided according to the risk value range.

[0024] In some embodiments, the flash evaporation suppression action in step S4 includes:

[0025] When a high-risk condition is identified, reduce the rate of change of valve opening to slow down the throttling process;

[0026] If the target opening is less than the preset flash critical opening, it is first adjusted to the critical opening and maintained for a preset time, and then adjusted to the target opening using a step-by-step optimization strategy; the flash critical opening is the minimum safe opening determined based on the valve's nominal diameter and the type of medium.

[0027] In some embodiments, the stepwise optimization strategy is as follows: the adjustment range is determined based on the current degree of effect deviation, and the system is continuously monitored for a preset duration after adjustment. If the effect does not improve, the adjustment is repeated until the expected control target is achieved.

[0028] In some embodiments, the flash protection action in step S4 includes:

[0029] Cooling medium is introduced into the cooling channel built into the hard-seal ball valve seat to control the temperature of the sealing surface to not exceed a preset threshold.

[0030] In some embodiments, the parameter set further includes the valve outlet medium temperature, and the evaluation and optimization of the flash suppression action in step S5 includes:

[0031] The suppression effect is assessed by the trend of the difference between the valve outlet pressure and the saturated vapor pressure and the range of risk value fluctuations.

[0032] If the difference continues to decrease and the risk value drops to the low-risk range, the suppression effect is considered to be good.

[0033] If the difference continues to increase or the risk value remains in the high-risk range for more than the preset time, it is determined that the suppression effect is insufficient and it is necessary to further reduce the rate of change of the opening or increase the critical opening of flash evaporation.

[0034] The evaluation and optimization of the flash protection action in step S5 includes:

[0035] The protection effect is assessed by the difference between the outlet and inlet temperatures of the valve medium and the attenuation trend of vibration acceleration.

[0036] If the difference is greater than or equal to the preset threshold and the vibration acceleration is less than or equal to the safety threshold, the protection effect is considered good.

[0037] If the difference is less than the preset threshold or the vibration acceleration is greater than the safety threshold, the protection effect is deemed insufficient, and the cooling medium flow rate needs to be increased.

[0038] In some embodiments, database creation and retrieval are also included, comprising the steps of:

[0039] The system stores historical parameter sets and corresponding optimized flash evaporation suppression and flash evaporation protection parameters in real time, forming a mapping dataset.

[0040] When the deviation between the parameter set collected in real time during subsequent operation and the historical dataset in the database is less than or equal to a preset threshold, the optimized action parameters corresponding to the historical dataset are directly retrieved and executed.

[0041] At preset intervals, new parameter sets and optimized action parameters are added to the database. If the same parameter set corresponds to multiple optimization results, the parameter with the best control effect is retained as the default value.

[0042] Secondly, this application provides a hard-seal ball valve, including a valve body, a ball, a valve stem, an actuator, a data acquisition component, and a controller. The actuator drives the ball to rotate via the valve stem. Valve seats are provided on both sides of the ball inside the valve body. The valve body includes an outlet end and an inlet end. The data acquisition component is connected to the controller and includes an inlet end pressure sensor for measuring inlet end pressure, an outlet end pressure sensor for measuring outlet end pressure, an inlet end temperature sensor for measuring inlet end temperature, an inlet end temperature sensor for measuring outlet end temperature, and an externally attached piezoelectric sensor for measuring the vibration acceleration of the valve body. A cooling channel structure is provided on the valve seat near the sealing area between the ball and the valve seat.

[0043] The beneficial effects of the present invention are as follows: The present invention effectively solves the problem of flashing of high-pressure liquid media in hard-seal ball valves by accurately determining flashing based on media characteristics and core parameters, and implementing flashing suppression and flashing protection respectively. Attached Figure Description

[0044] 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 some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0045] Figure 1 This is a flowchart of a control method for preventing flashing of high-pressure liquid medium in a hard-seal ball valve according to the present invention;

[0046] Figure 2 This is a logic diagram of a control method for preventing flash evaporation of high-pressure liquid medium in a hard-seal ball valve according to the present invention.

[0047] Figure 3 This is a schematic diagram of a hard-seal ball valve according to the present invention. Detailed Implementation

[0048] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "longitudinal", "lateral", "radial", "length", "width", "thickness", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element or component to have a specific orientation, or to be constructed and operated in a specific orientation.

[0050] It should be noted that the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are only used to distinguish different components and should not be construed as limiting the embodiments of this application.

[0051] It should be noted that the terms "installation," "setup," "equipped with," "connection," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two devices, components, or parts.

[0052] It should be noted that the terms "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "in some embodiments," "exemplarily," and "for example" is intended to present related concepts in a specific manner, meaning that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the above terms in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0054] Regarding the accompanying drawings of this application, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not necessarily drawn to scale.

[0055] like Figure 1 and Figure 2 As shown, a control method for preventing flashing of high-pressure liquid media in a hard-seal ball valve includes the following steps:

[0056] Step S1: Based on the composition characteristics of the actual high-pressure liquid medium inside the hard-seal ball valve, select the corresponding saturation pressure-temperature curve; it can be understood that the saturation pressure-temperature curves corresponding to various high-pressure liquid media are stored in the controller in advance.

[0057] Specifically, for single-component media, the Antoni equation is used to fit the curve. The equation is as follows:

[0058] (ln) P = A - B / ( T + C );

[0059] in A , B , C These are the characteristic constants of the medium, which can be found in a handbook, such as the constants for pure water at 0-100℃. A =8.07131、 B =1730.63、 C =233.426);

[0060] For multi-component media, the mixed saturated vapor pressure is calculated by weighting the mole fraction of each component, and the corresponding curve of temperature versus mixed saturated vapor pressure is obtained by fitting.

[0061] Step S2: Real-time acquisition of parameter sets, with a sampling frequency of 1-10 times / second, adjusted according to operating conditions. The parameter sets shall include at least:

[0062] The valve inlet pressure is measured by a piezoelectric pressure sensor with an accuracy of ±0.02MPa, which is embedded inside the inlet flange. The detection surface is flush with the inner wall of the pipe to avoid flow field disturbance.

[0063] Valve outlet pressure, a similar sensor, is installed inside the outlet flange.

[0064] The valve inlet medium temperature is measured using a Class A PT100 platinum resistance sensor with an insertion-type installation. The probe extends 1 / 3 of the pipe's inner diameter and is located 5 times the pipe diameter downstream of the inlet pressure sensor to avoid local pressure fluctuations affecting temperature measurement.

[0065] The valve outlet medium temperature sensor, of the same type, is installed 5 times the pipe diameter downstream of the outlet pressure sensor.

[0066] The valve opening change rate is calculated by using the absolute encoder built into the valve actuator, with a resolution of ≥1000 lines / revolution. It rotates synchronously with the valve stem through mechanical linkage to calculate the change in opening per unit time.

[0067] The valve vibration acceleration is measured using an external piezoelectric sensor mounted on the outer wall of the valve body. A 0.5mm thick thermally conductive silicone pad is placed between the sensor and the valve body to ensure the efficiency of vibration signal transmission. The measurement range is 0-5g, with an accuracy of ±0.01g.

[0068] Step S3: Obtain the corresponding saturated vapor pressure based on the valve inlet medium temperature, and determine whether flash evaporation has occurred by comparing the valve outlet pressure with the saturated vapor pressure;

[0069] Based on the saturated pressure-temperature curve from step S1 and the parameter set from step S2, flash evaporation is determined using a triple logic approach combining pressure comparison, trend analysis, and vibration characteristics.

[0070] First, by referring to the saturated pressure-temperature curve based on the temperature of the imported medium, the saturated vapor pressure of the medium under the current operating conditions can be obtained.

[0071] If the valve outlet pressure is less than the saturated vapor pressure, and any of the following anti-interference conditions are met simultaneously, then flash evaporation is determined to have occurred:

[0072] Anti-interference condition A: The absolute value of the valve outlet pressure change rate is ≤0.2MPa / s, excluding sudden drops caused by sudden closing / opening of downstream valves;

[0073] Anti-interference condition B: Valve vibration acceleration a>0.3g. Generally, the gas-liquid two-phase flow generated by flash evaporation impacts the valve body, exhibiting high-frequency vibration characteristics, which is different from the low-frequency vibration of pipeline water hammer.

[0074] If the valve outlet pressure is greater than or equal to the saturated vapor pressure, and any of the following anti-interference conditions are met simultaneously, then flash evaporation is determined not to have occurred:

[0075] Anti-interference condition C: The rate of change of valve inlet pressure and the rate of change of valve outlet pressure are positive and negative, that is, the trend of change is consistent, and the ratio of the two is within the range of 0.8-1.2. This eliminates independent fluctuations downstream, such as the decrease in valve outlet pressure caused by downstream leakage.

[0076] Anti-interference condition D: Valve opening change rate ≤ 5° / s, thus eliminating instantaneous valve outlet pressure deviation caused by sudden changes in opening.

[0077] If none of the above conditions are met, it is determined to be an abnormal pressure fluctuation. The current control action is maintained, the parameter acquisition frequency is increased, and the process is repeated after continuous monitoring.

[0078] Step S4: If it is determined that flash evaporation has not occurred, the risk level is determined by the flash evaporation risk model, which includes high risk and low risk; if it is determined to be low risk, data collection is maintained; if it is determined to be high risk, flash evaporation suppression actions are executed to prevent flash evaporation from occurring.

[0079] The flash evaporation risk model is established as follows:

[0080] The formula for calculating the risk value is: ;

[0081] Core items The ratio of the difference between the outlet pressure and the saturated vapor pressure to the saturated vapor pressure reflects... and The degree of closeness The closer The larger the core item, the higher the risk.

[0082] First correction factor and valve opening change rate V Positive correlation, for example V ≤5° / s hour =1.0, 5° / s < V ≤10° / s hour =1.5, V >10° / s hour =2.0), the faster the opening is adjusted, the more drastic the throttling and pressure reduction, and the greater the risk.

[0083] The second correction factor is related to the inlet and outlet pressure difference Δ. P = - Positive correlation, such as Δ P ≤5 MPa hour =1.0, 5 MPa <Δ P ≤10 MPa hour =1.3, Δ P >10 MPa hour =1.6), the greater the pressure difference, the stronger the local throttling effect, and the greater the risk.

[0084] Risk levels are classified based on risk value ranges:

[0085] Low risk: F <0.5, at this time and The difference is significant, the risk of flash evaporation is low, and the parameter acquisition frequency of step S2 is maintained without the need for additional suppression actions;

[0086] High risk: F ≥0.5, at this time near Flash evaporation suppression action needs to be performed.

[0087] The flash evaporation suppression action includes:

[0088] Reduce valve opening change rate V ,Will V Adjust to ≤3° / s to slow down the throttling rate and avoid If the opening drops sharply, or if the target opening is less than the preset flash critical opening, the actuator will first be controlled to open the valve to the critical opening and hold it for 3-5 seconds to establish a stable flow field, and then the valve will be adjusted to the target opening using a step-by-step optimization strategy.

[0089] The stepwise optimization strategy is as follows: the adjustment range for each adjustment is determined based on the current degree of deviation in effect, that is, it is dynamically adjusted by the change in risk value. After adjustment, it is continuously monitored for a preset period of time. If the effect does not improve, the adjustment is repeated until the expected control target is reached, that is, the risk value is lower than 0.5.

[0090] Wherein, the target opening degree is the final opening degree required by the process.

[0091] The critical opening degree for flash evaporation is determined by CFD simulation or obtained through actual data accumulation based on the nominal diameter, nominal pressure and medium type of the valve. For example, when a DN200, PN16MPa ball valve is used to transport crude oil, the critical opening degree is 20%.

[0092] It is understandable that the target opening degree and the flash critical opening degree are pre-stored in the database and retrieved and used in advance when the valve is running.

[0093] If flashing is determined to have occurred, a flashing protection action is executed to reduce damage to the valve. The flashing protection action includes: introducing a cooling medium into the cooling channel built into the hard-seal ball valve seat to control the temperature of the sealing surface to not exceed a preset threshold. Optionally, the cooling medium is room temperature water, etc.

[0094] The cooling flow rate is controlled by a miniature proportional valve. The initial flow rate is 0.3 L / min. If the temperature difference between the outlet medium and the inlet medium is less than 4℃, the cooling effect is insufficient. The flow rate is then increased to 0.5 L / min to ensure that the sealing surface temperature is ≤120℃. It can be understood that the outlet medium temperature is indirectly reflected and is usually 5-10℃ lower than the sealing surface temperature.

[0095] In addition, a specially designed electromagnetic adjustable damping shock absorber can be used to adjust the damping based on the valve's vibration acceleration. a Adjust the damping force if a >0.5 g For every 0.1g increase in vibration acceleration, the damping force increases by 200N; if a ≤0.3 g To maintain the current damping force, the vibration acceleration will eventually be controlled within 0.3g to avoid vibration causing an increase in the sealing surface gap.

[0096] At the same time, the existing downstream baffle in the pipeline can be used. It is made of 316L stainless steel, 5mm thick, with an opening rate of 30%, and installed at a distance of 1 pipe diameter downstream of the valve outlet. The downstream baffle can disrupt the vortex shedding frequency of the gas-liquid two-phase flow and help reduce vibration.

[0097] Step S5: Evaluate the control effect based on the parameter set, and dynamically optimize the parameters for flash evaporation suppression and flash evaporation protection.

[0098] For flash evaporation suppression, the suppression effect is assessed by the trend of the difference between the valve outlet pressure and the saturated vapor pressure and the range of risk value fluctuations.

[0099] If the difference continues to decrease and the risk value drops to the low-risk range, the suppression effect is considered to be good.

[0100] If the difference continues to increase or the risk value remains in the high-risk range for more than the preset time, it is determined that the suppression effect is insufficient, and it is necessary to further reduce the rate of change of the opening or increase the critical opening of flash evaporation.

[0101] For flash protection actions, the protection effect is evaluated by the difference between the outlet and inlet medium temperatures and the attenuation trend of valve vibration acceleration.

[0102] If the difference is greater than or equal to the preset threshold and the vibration acceleration is less than or equal to the safety threshold, the protection effect is considered good.

[0103] If the difference is less than the preset threshold or the vibration acceleration is greater than the safety threshold, the protection effect is deemed insufficient, and the cooling medium flow rate needs to be increased.

[0104] After each parameter adjustment, monitor continuously for 1-3 minutes. If the effect does not improve, repeat the adjustment until the expected goal is achieved to avoid parameter oscillation.

[0105] Step S6: To avoid redundant optimization calculations and shorten response time, establish a parameter group-optimization parameter mapping database, which includes the following steps:

[0106] The system stores historical parameter sets and corresponding optimized flash suppression and protection parameters in real time, forming a mapping dataset. Preferably, when comparing with historical parameters, only valve inlet pressure can be compared: it determines the basis of throttling pressure difference and directly affects the critical opening of the suppression action; valve inlet temperature determines the saturated vapor pressure, which is the benchmark for risk assessment and relates to the adaptability of suppression / protection parameters; valve vibration acceleration directly reflects the required intensity of protection action, thus reducing the amount of comparison.

[0107] When the deviation between the parameter set collected in real time during subsequent operation and the historical dataset in the database is less than or equal to the preset threshold, the optimized action parameters corresponding to the historical dataset are directly retrieved and executed without recalculation.

[0108] At preset intervals, new parameter sets and optimized action parameters are added to the database. If the same parameter set corresponds to multiple optimization results, the parameter with the best control effect is retained as the default value.

[0109] The parameter with the largest inlet and outlet temperature difference and the smallest valve vibration acceleration is selected as the default value retrieved from the database. The essence of flash protection is to solve the two major damages of high temperature erosion and gas-liquid impact vibration. The inlet and outlet temperature difference and valve vibration acceleration are the most direct and easily quantifiable indirect indicators of these two damages.

[0110] This invention solves the core problem of flash evaporation control of high-pressure liquid media in hard-seal ball valves through a complete logic of "precise judgment - graded suppression - collaborative protection - efficient optimization - parameter reuse". It takes into account control accuracy, protection effect and implementation cost, and can be widely used in industrial high-pressure liquid transportation systems, with significant economic and practical value.

[0111] like Figure 3As shown, this application provides a hard-seal ball valve, including a valve body 1, a ball 2, a valve stem 3, an actuator, a data acquisition component, and a controller. The actuator drives the ball 2 to rotate via the valve stem 3. Valve seats 4 are provided on both sides of the ball 2 inside the valve body 1. The valve body 1 includes an outlet end and an inlet end. The data acquisition component is connected to the controller and includes: an inlet end pressure sensor for measuring inlet end pressure, an outlet end pressure sensor for measuring outlet end pressure, an inlet end temperature sensor for measuring inlet end temperature, an inlet end temperature sensor for measuring outlet end temperature, and a data acquisition component for measuring... An externally mounted piezoelectric sensor measures the vibration acceleration of the valve body. The sensor is installed on the outer wall of the valve body 1. A cooling channel structure 5 is provided on the valve seat 4 near the sealing point between the ball 2 and the valve seat 4. Exemplarily, the cooling channel structure 5 includes an annular groove formed on the valve seat, which, together with the inner wall of the valve body 1, forms a cooling channel. The cooling channel has independent inlet and outlet interfaces located symmetrically on the outer wall of the valve seat. Corresponding connectors are provided on the valve body, and an external cooling circulation device is connected to form a unidirectional circulation, preventing media stagnation. The inner wall of the cooling channel is polished, and corners are rounded to reduce flow resistance. Alternatively, existing valve seat cooling structures can be referenced.

[0112] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that the requirements of this application encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this application and are within the spirit and scope of the exemplary embodiments of this application.

[0113] Furthermore, it should be understood that in the foregoing description of the embodiments of this application, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this application. That is, the embodiments in this application can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0114] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments of this application. Other modified embodiments are also within the scope of this application. Therefore, the embodiments disclosed herein are merely examples and not limitations. Those skilled in the art can adopt alternative configurations to implement the applications in this application based on the embodiments in this application. Therefore, the embodiments of this application are not limited to the embodiments precisely described in the application.

Claims

1. A control method for preventing flashing of high-pressure liquid media in a hard-seal ball valve, characterized in that, The process includes the following steps: Step S1: Based on the composition characteristics of the actual high-pressure liquid medium inside the hard-seal ball valve, select the corresponding saturated pressure-temperature curve; Step S2: Real-time acquisition of parameter sets, which include at least the valve inlet pressure, valve outlet pressure, and valve inlet medium temperature; Step S3: Obtain the corresponding saturated vapor pressure based on the valve inlet medium temperature, and determine whether flashing has occurred by comparing the valve outlet pressure and the saturated vapor pressure; Step S4: If it is determined that flashing has not occurred, determine the risk level through a flashing risk model, which includes high risk and low risk; if it is determined to be low risk, maintain data acquisition; if it is determined to be high risk, execute flashing suppression actions to prevent flashing; if it is determined that flashing has occurred, execute flashing protection actions to reduce damage to the valve; Step S5: Evaluate the control effect based on the parameter set, and dynamically optimize the parameters of the flashing suppression and flashing protection actions; the parameter set also includes the valve opening change rate and valve vibration acceleration; The logic for determining whether flash evaporation has occurred in step S3 is as follows: if the valve outlet pressure is less than the saturated vapor pressure and the rate of change of the valve outlet pressure is within a gradual range, or the valve vibration acceleration exhibits the characteristics of gas-liquid two-phase flow impact, then flash evaporation is determined to have occurred; if the valve outlet pressure is greater than or equal to the saturated vapor pressure and the change trends of the valve inlet pressure and the valve outlet pressure are consistent, or the valve opening is in a stable adjustment state, then flash evaporation is determined not to have occurred; if none of the above conditions are met, then it is determined to be an abnormal pressure fluctuation, the current state is maintained and the parameter acquisition frequency is increased; The flash risk model described in step S4 is established as follows: the core term is the ratio of the difference between the outlet pressure and the saturated vapor pressure to the saturated vapor pressure; the first correction factor is positively correlated with the valve opening change rate, and the faster the opening adjustment, the larger the correction factor. The second correction factor is positively correlated with the pressure difference between the inlet and outlet; the larger the pressure difference, the larger the correction factor. The risk value is the product of the core item and the first and second correction factors, and high and low risk levels are divided according to the risk value range; The flash evaporation suppression action in step S4 includes: when a high risk is determined, reducing the rate of change of valve opening to slow down the throttling process; if the target opening is less than the preset flash critical opening, first adjusting to the critical opening and maintaining it for a preset time, and then adjusting to the target opening using a step-by-step optimization strategy; the flash critical opening is the minimum safe opening determined based on the nominal diameter of the valve and the type of medium. The flash protection action in step S4 includes: introducing a cooling medium into the cooling channel built into the hard-seal ball valve seat to control the temperature of the sealing surface to not exceed a preset threshold.

2. The control method for preventing flashing of high-pressure liquid medium in a hard-seal ball valve according to claim 1, characterized in that, In step S1, the saturation pressure-temperature curve is determined as follows: For single-component media, the Antoine equation is used to fit the curve; For multi-component media, the mixed saturated vapor pressure is calculated by weighting the mole fraction of each component, and the corresponding curve of temperature versus mixed saturated vapor pressure is obtained by fitting.

3. The control method for preventing flashing of high-pressure liquid medium in a hard-seal ball valve according to claim 1, characterized in that, The stepwise optimization strategy is as follows: the adjustment range is determined based on the current degree of effect deviation, and the system continuously monitors for a preset time after adjustment. If the effect does not improve, the adjustment is repeated until the expected control target is achieved.

4. The control method for preventing flashing of high-pressure liquid medium in a hard-seal ball valve according to claim 1, characterized in that, The parameter set also includes the valve outlet medium temperature. The evaluation and optimization of the flash suppression action in step S5 includes: The suppression effect is assessed by the trend of the difference between the valve outlet pressure and the saturated vapor pressure and the range of risk value fluctuations. If the difference continues to decrease and the risk value drops to the low-risk range, the suppression effect is considered to be good. If the difference continues to increase or the risk value remains in the high-risk range for more than the preset time, it is determined that the suppression effect is insufficient and it is necessary to further reduce the rate of change of the opening or increase the critical opening of flash evaporation. The evaluation and optimization of the flash protection action in step S5 includes: The protection effect is assessed by the difference between the outlet and inlet temperatures of the valve medium and the attenuation trend of vibration acceleration. If the difference is greater than or equal to the preset threshold and the vibration acceleration is less than or equal to the safety threshold, the protection effect is considered good. If the difference is less than the preset threshold or the vibration acceleration is greater than the safety threshold, the protection effect is deemed insufficient, and the cooling medium flow rate needs to be increased.

5. The control method for preventing flashing of high-pressure liquid medium in a hard-seal ball valve according to claim 1, characterized in that, It also includes database creation and retrieval, which includes the following steps: The system stores historical parameter sets and corresponding optimized flash evaporation suppression and flash evaporation protection parameters in real time, forming a mapping dataset. When the deviation between the parameter set collected in real time during subsequent operation and the historical dataset in the database is less than or equal to a preset threshold, the optimized action parameters corresponding to the historical dataset are directly retrieved and executed. At preset intervals, new parameter sets and optimized action parameters are added to the database. If the same parameter set corresponds to multiple optimization results, the parameter with the best control effect is retained as the default value.

6. A hard-seal ball valve, capable of performing the control method for preventing flashing of high-pressure liquid media as described in any one of claims 1 to 5, characterized in that, The device includes a valve body, a ball, a valve stem, an actuator, a data acquisition component, and a controller. The actuator drives the ball to rotate via the valve stem. Valve seats are located on both sides of the ball within the valve body. The valve body includes an outlet end and an inlet end. The data acquisition component and controller are connected and include an inlet end pressure sensor for measuring inlet end pressure, an outlet end pressure sensor for measuring outlet end pressure, an inlet end temperature sensor for measuring inlet end temperature, an inlet end temperature sensor for measuring outlet end temperature, and an externally mounted piezoelectric sensor for measuring the vibration acceleration of the valve body. A cooling channel structure is provided on the valve seat near the sealing area between the ball and the valve seat.

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