Intelligent anti-leakage monitoring method and system for valve stem seal

Abstract

This application relates to the field of sealing testing technology, specifically to an intelligent leak-proof monitoring method and system for valve stem seals. The method includes: real-time acquisition of the torque and displacement of the valve stem actuator end during movement, as well as the temperature within the stuffing box; analysis of the torque variation trend and fluctuation degree during each historical movement of the valve stem to determine the current dynamic torque trend anomaly; determination of the friction temperature coefficient of the valve stem during each movement, obtaining a correction value for the friction temperature coefficient; evaluation of the numerical distribution of the correction value during the historical movement of the valve stem, combined with the current dynamic torque trend anomaly, to obtain the thermal effect anomaly during the current valve stem movement, and in conjunction with the pressure within the stuffing box under static conditions, to test the valve stem sealing performance. This improves the accuracy of leak-proof monitoring of the valve stem seal.

Description

Technical Field

[0001] This application relates to the field of sealing test technology, specifically to an intelligent leak-proof monitoring method and system for valve stem seals. Background Technology

[0002] Valves, as key control components in fluid transport systems, are widely used in numerous industrial fields such as petroleum, chemical, natural gas, municipal water supply, and nuclear power. The valve stem seal is a crucial component preventing leakage of the medium inside the valve along the valve stem axis; its sealing performance directly affects production safety, environmental protection, and the long-term stable operation of the equipment.

[0003] Current technologies for leak prevention testing of valve stem seals primarily focus on consequence monitoring, waiting for leaking substances to overflow and accumulate to a detectable concentration. By this time, leakage has already occurred, and the seal has failed. Therefore, existing technologies lack monitoring of the seal failure process and cannot intervene at the inception or during the leakage process. Valve stem applications are highly sensitive to micro-leakage, requiring testing methods to detect leaks at an extremely early stage. Traditional testing relies on the characteristics of an already occurring leak as data support, which is insufficient to meet the high safety performance requirements of valve stem seals. Furthermore, it lacks collaborative monitoring and analysis of multi-dimensional data under both dynamic and static operating conditions of the valve stem, failing to establish a correlation between dynamic friction characteristics and static sealing performance. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide an intelligent leak-proof monitoring method and system for valve stem seals, the specific technical solution of which is as follows:

[0005] In a first aspect, embodiments of this application provide an intelligent leak-proof monitoring method for valve stem seals, the method comprising the following steps:

[0006] Real-time acquisition of torque and displacement at the valve stem actuator end during movement, as well as temperature inside the stuffing box;

[0007] Analyze the trend and fluctuation of torque during each historical movement of the valve stem to determine the degree of abnormality of the current dynamic torque trend of the valve stem;

[0008] By analyzing the temperature change, torque distribution, and duration of each valve stem movement, the temperature rise per unit friction is quantified, and the friction temperature coefficient for each valve stem movement is determined. The friction temperature coefficient is then corrected by using the proportion of the valve stem displacement in each movement to the total displacement in the historical movement, resulting in a corrected value for the friction temperature coefficient of each valve stem movement.

[0009] The numerical distribution of the correction values ​​during the historical movement of the valve stem is evaluated. Combined with the current abnormality of the dynamic torque trend of the valve stem, the abnormality of the thermal effect during the current valve stem movement is obtained. In conjunction with the pressure in the stuffing box under static conditions, the valve stem sealing performance is tested.

[0010] In one embodiment, determining the anomaly of the current valve stem's dynamic torque trend includes:

[0011] Calculate the average value and dispersion of all torques collected during each movement of the valve stem, perform linear fitting on the average value of all historical movements of the valve stem, and obtain the slope of the fitted line;

[0012] The dynamic torque trend anomaly is determined based on the slope and the degree of dispersion, wherein the dynamic torque trend anomaly is positively correlated with both the slope and the degree of dispersion.

[0013] In one embodiment, the mean of the dispersion over all historical movements of the valve stem is calculated and multiplied by the slope to obtain the current dynamic torque trend anomaly of the valve stem.

[0014] In one embodiment, determining the frictional temperature coefficient for each movement of the valve stem includes:

[0015] Calculate the product of the average value of all torques collected during each movement of the valve stem and the movement time. The frictional temperature coefficient of the valve stem during each movement is the ratio of the temperature change to the product.

[0016] In one embodiment, the temperature change is the difference between the maximum temperature inside the stuffing box during each movement of the valve stem and the temperature inside the stuffing box at the moment before each movement of the valve stem begins.

[0017] In one embodiment, the proportion of the displacement of the valve stem in each movement process to the maximum displacement of all its historical movements is determined, and the correction value of the frictional temperature coefficient of the valve stem in each movement is the ratio of the frictional temperature coefficient of the valve stem in each movement to the proportion.

[0018] In one embodiment, obtaining the thermal effect anomaly degree during the current valve stem movement includes:

[0019] The calculation is based on the cumulative sum of the correction values ​​of the friction temperature coefficient corresponding to all valve stem movements up to the present. The thermal effect anomaly of the current valve stem movement process is positively correlated with the cumulative sum and the dynamic torque trend anomaly.

[0020] In one embodiment, the thermal effect anomaly of the current valve stem movement is the product of the sum and the dynamic torque trend anomaly.

[0021] In one embodiment, the test valve stem sealing performance specifically includes:

[0022] During the normal operation of the valve, the thermal effect anomaly during multiple valve stem movements and the pressure inside the stuffing box under static conditions are obtained to establish a healthy baseline.

[0023] Calculate the thermal effect anomaly during the current valve stem movement process and the deviation between the pressure inside the stuffing box and the healthy baseline under the current static operating conditions. Detect the anomalies of these deviations. If an abnormal deviation exists, trigger a leakage warning; otherwise, do not trigger a leakage warning.

[0024] Secondly, embodiments of this application also provide an intelligent leak-proof monitoring system for valve stem seals, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of any of the methods described above.

[0025] This application has at least the following beneficial effects:

[0026] This application acquires real-time data on torque, displacement, and temperature within the stuffing box at the valve stem actuator end. Through multi-dimensional data collaborative analysis, it can accurately monitor the dynamic performance of the valve stem. In particular, by analyzing torque and temperature changes, it can more accurately determine the sealing status of the valve stem. Secondly, by analyzing the torque change trend during each historical movement of the valve stem, it can better identify torque fluctuations at different working stages, obtain the anomaly degree of the dynamic torque trend, enhance anomaly monitoring capabilities, facilitate early warning, and improve equipment safety. Furthermore, by calculating the frictional temperature coefficient of the valve stem for each movement, it can dynamically quantify the temperature rise caused by valve stem friction, enabling the monitoring of the valve stem frictional heat effect. More precise, it can reflect the impact of friction loss on sealing performance in real time, effectively preventing seal failure caused by excessively high friction temperature; by correcting the friction temperature coefficient, it avoids the difference in stroke of the valve stem under different operating conditions, making the determination of the frictional heat effect of the valve stem more accurate, which helps to dynamically assess the frictional temperature rise of the valve stem; by coordinating the monitoring of the pressure in the stuffing box under static conditions and the dynamic monitoring of the valve stem temperature change, it can more comprehensively judge the sealing performance of the valve stem, establish the correlation between dynamic friction characteristics and static sealing performance, help to accurately capture the very early signal of seal leakage, avoid the continuous deterioration of the sealing device, reduce maintenance costs, and improve the accuracy and effectiveness of valve stem seal leakage prevention monitoring. Attached Figure Description

[0027] To more clearly illustrate the technical solutions and advantages in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart illustrating the steps of an intelligent leak-proof monitoring method for valve stem seals, provided as an embodiment of this application. Detailed Implementation

[0029] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of an intelligent anti-leakage monitoring method and system for valve stem seals proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0031] The following description, in conjunction with the accompanying drawings, details the specific scheme of the intelligent leak-proof monitoring method and system for valve stem seals provided in this application.

[0032] Please see Figure 1 The diagram illustrates a flowchart of a smart leak-proof monitoring method for valve stem seals according to an embodiment of this application. The method includes the following steps:

[0033] S1 collects the torque and displacement of the valve stem actuator end during its movement in real time, as well as the temperature inside the stuffing box.

[0034] Changes in the characteristics of the process medium can affect the life of the seal. When there are trace impurities in the medium, or when there are fluctuations in temperature and pressure, although it will not directly cause leakage in the short term, it will accelerate the aging of the sealing material. A grease injection valve (one-way valve) is installed on the stuffing box. When a micro-leak is detected or preventive maintenance is performed, a high-pressure grease injection gun is used to inject special sealing grease into the sealing cavity to form an auxiliary sealing layer.

[0035] Therefore, in this embodiment, a high-response temperature sensor is embedded in the stuffing box to collect temperature data in real time. In addition, a torque sensor and a displacement sensor are installed at the valve stem actuator end to collect torque and displacement at the valve stem actuator end during movement in real time, laying a data foundation for analyzing the motion characteristics of the valve stem under dynamic working conditions.

[0036] It should be noted that temperature, torque, and displacement are all collected synchronously, and the collection frequency is set to 50Hz. Implementers can set it according to their actual situation, and this embodiment does not impose any restrictions on it.

[0037] S2, analyze the trend and fluctuation of torque changes during each historical movement of the valve stem, and determine the current abnormality of the dynamic torque trend of the valve stem.

[0038] In reactor feed control or other regulation scenarios in chemical plants, the valve stem of a regulating valve undergoes continuous stroke adjustments, with its movement cyclical through frequent actions of "acceleration start-up, constant speed operation, and deceleration stop." Monitoring the valve stem seal for leak prevention is crucial to ensure no leakage under static conditions. However, since the valve stem is stationary, direct leakage monitoring makes early warning difficult. Therefore, this embodiment introduces data analysis under dynamic conditions to provide very early warning of static sealing performance.

[0039] Sealing failure can be viewed as a gradual process. This embodiment achieves early warning by capturing multi-dimensional data features in the early stages of this process. Under dynamic operating conditions of the valve stem, parameters such as torque and displacement are monitored. Changes in these parameters can reflect the friction state and wear of the seal, directly affecting the sealing performance under static conditions.

[0040] When the valve stem moves, the friction between the seal and the valve stem generates heat and torque. If the seal is worn, lubrication fails, or preload is improper, friction will increase, manifesting as increased torque and abnormal temperature. Analyzing dynamic parameters such as torque and temperature can determine the health status of the seal, thereby predicting its sealing performance under static conditions.

[0041] Under normal operating conditions, the torque data of the valve stem should exhibit a uniform distribution. An increase in torque usually indicates increased friction, which may be due to factors such as packing creep, aging, or overtightening of the gland bolts. Even without leakage, these factors can cause the frictional torque to steadily increase. Therefore, by analyzing the torque of the valve stem during continuous dynamic operation and its growth slope over time, the degree of health degradation of the sealing device can be quantified. In this embodiment, each process of the valve stem moving from rest to motion and back to rest is considered as one movement process of the valve stem, and recorded as one dynamic operation cycle of the valve stem.

[0042] All torque data collected from each dynamic operation cycle of the valve stem are arranged in ascending order of time to form a torque data sequence for each dynamic operation cycle, and the average torque of the torque data sequence is calculated. Then, a linear fitting method is used to linearly fit the average torque of the torque data sequence of all dynamic operation cycles prior to each dynamic operation cycle of the valve stem, and the slope of the fitted line is obtained. This slope reflects the long-term deterioration trend of the torque. When the slope is positive and gradually increases, it indicates that the friction of the sealing device is continuously increasing, which is a very early signal of leakage. In this embodiment, the least squares method is used for linear fitting. Implementers can choose other existing feasible linear fitting methods, and this embodiment does not impose any restrictions on this.

[0043] Define the anomaly degree of the current valve stem's dynamic torque trend as follows:

[0044] In the formula, The degree of anomaly in the current dynamic torque trend of the valve stem. The slope of the fitted straight line representing the average torque of the torque data sequence from all historical dynamic operation cycles up to the current i-th dynamic operation cycle. This represents the average dispersion of the torque data sequence across all historical dynamic operation cycles up to the current i-th dynamic operation cycle. It should be noted that the dispersion can be calculated using methods such as variance, standard deviation, and coefficient of variation; this embodiment uses standard deviation for calculation.

[0045] It should be understood that the slope It reflects the long-term trend of torque. When the torque increases over time, the slope is positive and the larger the value, the more obvious the upward trend of torque. This reflects the overall fluctuation level of torque data, when The larger the value, the more unstable the torque change is. The greater the abnormality of the dynamic torque trend, the more it indicates a systematic deterioration of the valve stem friction.

[0046] S3. By measuring the temperature change, torque distribution, and movement duration during each movement of the valve stem, the temperature rise generated by a unit of friction is quantified, and the friction temperature coefficient for each movement of the valve stem is determined. The friction temperature coefficient is then corrected by using the proportion of the displacement of each movement of the valve stem in the displacement of the historical movement process, thus obtaining the corrected value of the friction temperature coefficient for each movement of the valve stem.

[0047] Abnormal changes in torque data affect the valve stem by insufficient preload due to negative feedback. This only indicates increased resistance, which may be caused by machine interference such as valve stem bending, and does not necessarily indicate a risk of leakage. Therefore, this embodiment combines the energy conversion phenomenon of frictional work into heat energy due to the inevitable friction of the valve stem under abnormal operating conditions, and introduces the frictional temperature coefficient to further effectively analyze the early leakage risk.

[0048] When the valve stem actuates, excessive friction between the packing and the valve stem can cause an abnormal increase in local temperature. Monitoring the temperature change can help determine whether the packing has failed to lubricate or whether the preload is too high.

[0049] For each dynamic operating cycle of the valve stem, the frictional temperature coefficient of each movement of the valve stem is determined, reflecting the temperature rise efficiency caused by unit friction. The specific expression is as follows:

[0050] In the formula, Let be the frictional temperature coefficient of the valve stem during the j-th movement. This represents the maximum temperature inside the stuffing box during the j-th movement of the valve stem. Let be the temperature inside the stuffing box at the moment before the j-th movement of the valve stem begins. This represents the average value of all torques collected during the j-th movement of the valve stem. Let be the total duration of the j-th movement of the valve stem.

[0051] It should be understood that, This represents the net temperature rise generated by the j-th movement of the valve stem, directly quantifying the heat generated by friction; the denominator... This represents the total friction generated during the j-th motion. Since the valve stem speed is constant and the stem angle is proportional to time, a larger torque and a longer motion duration result in greater work generated by friction. The friction temperature coefficient... It reflects the temperature rise generated per unit of friction. The higher the friction temperature coefficient, the higher the efficiency of converting mechanical energy into heat energy, and the more severe the friction conditions.

[0052] This embodiment monitors the frictional temperature coefficient to reflect the intensity of frictional heat generation between the packing and the valve stem. When the lubricant in the packing is depleted or the packing undergoes oxidation, the frictional temperature coefficient increases. This manifests as a significantly higher temperature rise rate and peak temperature of the packing gland under the same valve stem and speed, which is the most direct thermodynamic manifestation of increased seal wear.

[0053] However, under different dynamic operating conditions, the valve stem will have different strokes, resulting in significant differences in the generated torque and temperature rise. This difference in stroke directly affects the calculation of frictional work, thus interfering with the accurate assessment of the frictional temperature coefficient. Therefore, this embodiment eliminates the influence of stroke on the frictional temperature coefficient under different dynamic operating conditions, focusing only on the "frictional heat effect per unit distance".

[0054] For the j-th movement of the valve stem, its friction temperature coefficient is corrected by combining the maximum displacement during all its historical movements to eliminate interference from stroke variables. The specific expression is as follows:

[0055] In the formula, This is the correction value for the frictional temperature coefficient of the valve stem during its j-th movement. Let be the frictional temperature coefficient of the valve stem during the j-th movement. Let be the displacement of the valve stem during its j-th movement. The maximum displacement is the sum of all historical motions of the valve stem during its j-th motion.

[0056] It should be understood that by correcting the friction temperature coefficient, the unit-time frictional heat effect of the friction temperature coefficient affected by the stroke is converted into a stable unit-stroke frictional heat effect that can reflect the condition of the valve stem, thus solving the problem of incomparable data under different stroke conditions and achieving accurate reflection of early leakage.

[0057] S4. Evaluate the numerical distribution of the correction values ​​during the historical movement of the valve stem, combine the current dynamic torque trend anomaly of the valve stem, obtain the thermal effect anomaly during the current valve stem movement, and test the valve stem sealing performance in conjunction with the pressure in the stuffing box under static conditions.

[0058] Based on the current abnormality of the dynamic torque trend of the valve stem under dynamic operating conditions, and combined with the change in the correction value of its friction temperature coefficient, when the torque trend of the valve stem is abnormal under continuous dynamic operating conditions, the sealing surface is in a state of dry friction, which will accelerate the wear of the seal and lead to rapid degradation of static sealing performance. Anomalies under multiple consecutive dynamic operating cycles can reflect a systematic, gradual degradation process. Therefore, the abnormality of the thermal effect during the current valve stem movement process is determined as follows:

[0059] The calculation is based on the sum of the correction values ​​of the friction temperature coefficients corresponding to all valve stem movements up to the present. The thermal effect anomaly of the current valve stem movement process is positively correlated with the sum and the dynamic torque trend anomaly of the current valve stem.

[0060] In this embodiment, the thermal effect anomaly degree of the current valve stem movement process is the product of the accumulated sum and the dynamic torque trend anomaly degree of the current valve stem.

[0061] It should be understood that the greater the anomaly of the dynamic torque trend, the higher the degree of torque anomaly. In this case, there is a certain risk of leakage for the valve stem during static operation that requires high-strength sealing. Furthermore, the friction temperature coefficient represents the temperature rise generated by friction work under dynamic operating conditions of the valve stem. When the correction value of the friction temperature coefficient under continuous dynamic operating cycles is larger and the trend of change is gradually increasing, it reflects that the heat energy converted from friction caused by the abnormal increase in torque is being monitored and reflected in the friction temperature data. Therefore, the larger the correction value of the friction temperature coefficient and the stronger the increasing trend, the greater the anomaly of the thermal effect of the valve stem under dynamic operating conditions.

[0062] When the valve stem experiences dry friction due to lubricant depletion or other reasons, the frictional force increases, and almost all of the frictional energy is converted into heat energy, thus increasing the frictional temperature coefficient. This is an extremely early sign of seal leakage, because dry friction will rapidly wear down the packing and form a leakage channel.

[0063] An increase in temperature inside the stuffing box could be due to increased friction or changes in ambient temperature; an increase in torque could be due to a problem with the packing or a bent valve stem. However, only the coordinated change in temperature inside the stuffing box and torque on the valve stem over time can definitively determine that the problem lies with the frictional characteristics of the seal itself.

[0064] Abnormalities in the valve stem under dynamic conditions usually occur earlier than abnormalities in the sealing device under static conditions. When the abnormality of thermal effect under dynamic conditions indicates abnormal degradation of the sealing state, the sealing performance should be comprehensively judged by combining the pressure data in the stuffing box under static conditions.

[0065] During the normal operation of the valve, the thermal effect anomaly degree during M valve stem movements and the pressure data within the stuffing box under static conditions are collected to establish a health baseline, reflecting the data distribution under normal sealing conditions. In this embodiment, M=10, but the implementer can set it according to actual conditions; this embodiment does not impose any restrictions on this. It should be noted that the health baseline in this embodiment refers to the range of values ​​for the thermal effect anomaly degree and the pressure data within the stuffing box under normal sealing conditions; the pressure data within the stuffing box is obtained through a pressure sensor installed on the inner wall of the stuffing box.

[0066] Calculate the thermal effect anomaly degree of the latest valve stem movement and the deviation of the pressure in the stuffing box from the healthy baseline under the current static condition. Taking the thermal effect anomaly degree as an example, if the thermal effect anomaly degree of the latest valve stem movement is within the range of the healthy baseline, the deviation is 0. If the thermal effect anomaly degree of the latest valve stem movement is greater than the maximum value of the healthy baseline range, the deviation is the difference between the thermal effect anomaly degree of the latest valve stem movement and the maximum value of the healthy baseline range. If the thermal effect anomaly degree of the latest valve stem movement is less than the minimum value of the healthy baseline range, the deviation is the difference between the minimum value of the healthy baseline range and the thermal effect anomaly degree of the latest valve stem movement. Anomaly detection is performed on this deviation. If an abnormal deviation exists, a leakage warning is triggered; otherwise, no leakage warning is triggered. It should be noted that the anomaly detection in this embodiment adopts a threshold setting method. If the deviation is greater than or equal to the set threshold, it is determined to be an abnormal deviation; otherwise, it is determined to be a normal deviation. The threshold set in this embodiment is 5%, and the implementer can set it according to the actual situation. The implementer can choose other existing feasible anomaly detection algorithms, and this embodiment does not restrict this.

[0067] Based on the same inventive concept as the above method, this application embodiment also provides an intelligent anti-leakage monitoring system for valve stem seals, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-described intelligent anti-leakage monitoring methods for valve stem seals.

[0068] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments of this specification have been described above. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0069] 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.

[0070] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A smart leak-proof monitoring method for valve stem seals, characterized in that, The method includes the following steps: Real-time acquisition of torque and displacement at the valve stem actuator end during movement, as well as temperature inside the stuffing box; Analyze the trend and fluctuation of torque during each historical movement of the valve stem to determine the degree of abnormality of the current dynamic torque trend of the valve stem; By analyzing the temperature change, torque distribution, and duration of each valve stem movement, the temperature rise per unit friction is quantified, and the friction temperature coefficient for each valve stem movement is determined. The friction temperature coefficient is then corrected by using the proportion of the valve stem displacement in each movement to the total displacement in the historical movement, resulting in a corrected value for the friction temperature coefficient of each valve stem movement. The numerical distribution of the correction values ​​during the historical movement of the valve stem is evaluated. Combined with the current abnormality of the dynamic torque trend of the valve stem, the abnormality of the thermal effect during the current valve stem movement is obtained. In conjunction with the pressure in the stuffing box under static conditions, the valve stem sealing performance is tested.

2. The intelligent leak-proof monitoring method for valve stem seals as described in claim 1, characterized in that, The determination of the current valve stem's dynamic torque trend anomaly includes: Calculate the average value and dispersion of all torques collected during each movement of the valve stem, perform linear fitting on the average value of all historical movements of the valve stem, and obtain the slope of the fitted line; The dynamic torque trend anomaly is determined based on the slope and the degree of dispersion, wherein the dynamic torque trend anomaly is positively correlated with both the slope and the degree of dispersion.

3. The intelligent leak-proof monitoring method for valve stem seals as described in claim 2, characterized in that, The mean of the dispersion during all historical movements of the valve stem is calculated and multiplied by the slope to obtain the current dynamic torque trend anomaly of the valve stem.

4. The intelligent leak-proof monitoring method for valve stem seals as described in claim 1, characterized in that, The determination of the frictional temperature coefficient for each movement of the valve stem includes: Calculate the product of the average value of all torques collected during each movement of the valve stem and the movement time. The frictional temperature coefficient of the valve stem during each movement is the ratio of the temperature change to the product.

5. The intelligent leak-proof monitoring method for valve stem seals as described in claim 4, characterized in that, The temperature change is the difference between the maximum temperature inside the stuffing box during each movement of the valve stem and the temperature inside the stuffing box at the moment before each movement of the valve stem begins.

6. The intelligent leak-proof monitoring method for valve stem seals as described in claim 1, characterized in that, The proportion of the displacement of the valve stem in each movement process to the maximum displacement of all its historical movements is determined, and the correction value of the friction temperature coefficient of the valve stem in each movement is the ratio of the friction temperature coefficient of the valve stem in each movement to the aforementioned proportion.

7. The intelligent leak-proof monitoring method for valve stem seals as described in claim 1, characterized in that, The acquisition of the thermal effect anomaly degree during the current valve stem movement process includes: The calculation is based on the cumulative sum of the correction values ​​of the friction temperature coefficient corresponding to all valve stem movements up to the present. The thermal effect anomaly of the current valve stem movement process is positively correlated with the cumulative sum and the dynamic torque trend anomaly.

8. The intelligent leak-proof monitoring method for valve stem seals as described in claim 7, characterized in that, The thermal effect anomaly degree of the current valve stem movement process is the product of the accumulated sum and the dynamic torque trend anomaly degree.

9. The intelligent leak-proof monitoring method for valve stem seals as described in claim 1, characterized in that, The test valve stem sealing performance is specifically as follows: During the normal operation of the valve, the thermal effect anomaly during multiple valve stem movements and the pressure inside the stuffing box under static conditions are obtained to establish a healthy baseline. Calculate the thermal effect anomaly during the current valve stem movement process and the deviation between the pressure inside the stuffing box and the healthy baseline under the current static operating conditions. Detect the anomalies of these deviations. If an abnormal deviation exists, trigger a leakage warning; otherwise, do not trigger a leakage warning.

10. An intelligent leak-proof monitoring system for valve stem seals, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1-9.

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