A pressure vessel sealing structure performance detection device

Abstract

The application relates to the technical field of sealing performance detection, in particular to a pressure container sealing structure performance detection equipment, which comprises a fixing device for loading a pressure container, a negative pressure device for vacuumizing the pressure container, a detection device for periodically detecting the actual negative pressure change rate in the pressure container, and an analysis module for obtaining the actual negative pressure change rate detected by the detection device and the expected negative pressure change rate determined by the negative pressure device, and determining whether the sealing performance of the pressure container meets the standard according to the absolute value of the difference between the negative pressure change rate ratio of the actual negative pressure change rate and the expected negative pressure change rate and a preset ratio. The application improves the accuracy of the sealing performance detection process analysis and the accuracy of the sealing performance detection result.

Description

Technical Field

[0001] This invention relates to the field of sealing performance testing technology, and in particular to a pressure vessel sealing structure performance testing device. Background Technology

[0002] In industries such as chemical, energy, aerospace, and pharmaceutical, pressure vessels are key equipment for storing and transporting high-pressure media. The performance of their sealing structures directly affects production safety, energy efficiency, and environmental safety. Currently, the performance testing of pressure vessel sealing structures mainly employs techniques such as pneumatic testing, hydrostatic testing, and vacuum testing. However, existing testing technologies still have many limitations in practical applications. Traditional negative pressure devices often use preset fixed rates of negative pressure change, failing to consider the impact of power fluctuations on negative pressure changes during equipment operation. Furthermore, the sealing performance assessment mechanism is not precise enough, and the testing cycle lacks dynamic adjustment capabilities.

[0003] Chinese Patent Application No. CN117213992A discloses a pressure testing device for a pressure vessel. An upper seal is slidably mounted coaxially on the upper end of a lower seal. An elastic, annular sealing cover is installed on the inner ring side of the lower seal. The lower seal presses the lower end of the sealing cover against the upper surface of a horizontal section. Multiple arc-shaped upper pressure plates are spaced circumferentially on the upper surface of the upper seal. These upper pressure plates press the upper end of the sealing cover between the upper surface of the upper pressure plate and the lower surface of the flange. A first rod is rotatably connected to the lower seal. The end of a second rod away from the first rod is rotatably connected to its corresponding upper pressure plate. The second rod can slide radially along the upper pressure plate. The end of a telescopic rod away from the sealing cover is rotatably connected to its corresponding first and second rods. This invention improves the sealing performance of the pressure testing chamber, thereby achieving accurate testing of the pressure vessel, and is easy to operate.

[0004] However, existing technologies still have the following problems: the expected negative pressure change rate is not associated with the dynamic characteristics of power setting, the sealing judgment mechanism is simple, lacks dynamic adjustment and secondary verification, and lacks the ability to diagnose the causes of sealing failure, making it impossible to achieve accurate positioning. Summary of the Invention

[0005] To address these issues, the present invention provides a pressure vessel sealing structure performance testing device to overcome the problems in the prior art, such as the lack of correlation between the expected negative pressure change rate and the dynamic characteristics of power, the single sealing performance judgment mechanism, the lack of dynamic adjustment and secondary verification, and the inadequate ability to diagnose the causes of sealing performance failure, thus failing to achieve precise positioning.

[0006] To achieve the above objectives, the present invention provides a pressure vessel sealing structure performance testing device. It includes:

[0007] A mounting device used for loading pressure vessels;

[0008] A negative pressure device is used to evacuate the pressure vessel. The negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power, and the negative pressure device increases its operating power during operation to increase the expected negative pressure change rate.

[0009] A detection device for periodically detecting the actual rate of change of negative pressure inside the pressure vessel;

[0010] An analysis module, connected to the detection device and the negative pressure device respectively, is used to acquire the actual negative pressure change rate detected by the detection device and the expected negative pressure change rate determined by the negative pressure device, and to determine whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and a preset ratio, and to determine the reason why the sealing performance of the pressure vessel does not meet the standard when the sealing performance of the pressure vessel does not meet the standard based on the absolute value of the difference.

[0011] Furthermore, the negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power and the product of the reference negative pressure change rate.

[0012] Furthermore, the analysis module determines whether the pressure vessel's sealing performance meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and a preset ratio.

[0013] If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is less than the first preset difference, then the sealing performance of the pressure vessel is determined to meet the standard.

[0014] If the absolute value of the difference between the ratio of negative pressure change rate and the preset ratio is greater than or equal to the first preset difference and less than the second preset difference, then it is determined whether the sealing performance of the pressure vessel meets the standard based on the cumulative test duration.

[0015] If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is greater than or equal to the second preset difference, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference.

[0016] Furthermore, the analysis module makes a secondary determination of whether the pressure vessel's sealing performance meets the standards based on the cumulative test duration, wherein...

[0017] If the cumulative test duration is greater than or equal to the preset cumulative test duration, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference.

[0018] If the cumulative test duration is less than the preset cumulative test duration, then the corrected detection cycle is determined.

[0019] Furthermore, the analysis module adjusts the detection cycle based on the difference between the preset cumulative test duration and the actual cumulative test duration, and the increase in the detection cycle is positively correlated with the difference between the preset cumulative test duration and the actual cumulative test duration.

[0020] Furthermore, the analysis module is based on the detection period corrected by reducing the attenuation coefficient.

[0021] Furthermore, the analysis module determines the reason why the pressure vessel's sealing performance does not meet the standard based on the difference between the absolute value of the difference and the second preset difference, wherein...

[0022] If the difference between the absolute value of the difference and the second preset difference is less than a preset threshold, then the container is determined to be unqualified.

[0023] If the difference between the absolute value of the difference and the second preset difference is greater than or equal to the preset threshold, then a preset number of historical absolute values ​​of the difference are obtained, and the operating power of the negative pressure device at each node is adjusted according to the average value of each historical absolute value of the difference.

[0024] Furthermore, the analysis module adjusts the operating power of the negative pressure device at each node based on the average value of the absolute values ​​of each historical difference, and the increase in the operating power is negatively correlated with the average value of the absolute values ​​of each historical difference.

[0025] Furthermore, after the analysis module completes the analysis of the operating power of a single node, it reduces the rate of increase of the expected negative pressure change rate based on the adjusted operating power. The magnitude of the reduction in the rate of increase of the expected negative pressure change rate is positively correlated with the operating power.

[0026] Furthermore, after the analysis module has adjusted the operating power, it re-determines whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and the preset ratio. If the sealing performance of the pressure vessel still does not meet the standard, it determines that the reason is that the seal at the interface between the negative pressure device and the pressure vessel is unqualified, and issues a sealing inspection notice.

[0027] Compared with existing technologies, the advantages of this invention lie in its determination of the expected negative pressure change rate by multiplying the ratio of the current operating power to the rated power by the reference negative pressure change rate. This fully considers the differences in the actual operating state of the negative pressure device under different power levels, rather than relying solely on a fixed value under rated power. It dynamically matches the real-time operating conditions of the device, avoiding discrepancies between the expected value and the actual scenario caused by power fluctuations. A three-level judgment mechanism is employed to quickly identify clearly qualified or severely leaking situations, and to conduct secondary confirmation of ambiguous intermediate states through accumulated test time, avoiding misjudgments caused by instantaneous fluctuations. This layered processing balances detection efficiency and judgment accuracy, making it particularly suitable for scenarios with strict sealing requirements.

[0028] Furthermore, the secondary judgment mechanism of this invention introduces "cumulative test duration" as a supplementary judgment criterion for the boundary case where "the absolute value of the difference is between the first and second preset differences." This prevents misjudgment of compliance due to insufficient testing time (when the sealing state is not yet stable) and avoids over-testing of obviously unqualified containers. By controlling the maximum testing cycle through preset cumulative test duration, the contradiction between "accuracy" and "efficiency" is effectively balanced. When the cumulative test duration is insufficient, the "corrected testing cycle" (extended testing time) is used to allow the sealing state to fully stabilize before judgment, reducing misjudgments caused by instantaneous fluctuations or failure to reach a stable state. This dynamic adjustment mechanism makes the testing process more closely match the actual changing law of container sealing performance (such as the negative pressure state may gradually stabilize over time), further improving the reliability of the judgment results. For containers that are still in a boundary state after the cumulative test duration reaches the target, they are directly judged as unqualified and the reasons are analyzed, ensuring strict control over potential leakage risks. This allows the test results to not only determine the state but also provide more accurate guidance for subsequent improvements.

[0029] Furthermore, this invention transforms periodic correction into a quantifiable calculation process, avoiding subjective, experience-based adjustments. This linearly positively correlated correction logic (the larger the difference, the greater the increase) accurately matches the "extra time required for the sealed state to stabilize," making the extended detection cycle more aligned with the actual stabilization time needed by the container, reducing the problems of excessive extension or insufficient correction. The first proportional coefficient is determined through historical case statistics and regression analysis, with the secondary judgment accuracy as the optimization objective. Typical cases of "insufficient cumulative time during secondary judgment" are selected for analysis to ensure that parameter optimization is based on pain points in real detection scenarios. The optimal coefficient is found through regression analysis, giving the correction mechanism a data-driven scientific basis and avoiding the blind setting of parameters. For cases of insufficient cumulative testing time, the detection cycle is extended in a targeted manner, giving containers whose sealed state has not yet stabilized sufficient "stabilization time," allowing subsequent judgments to be based on more reliable steady-state data. This avoids the inefficiency caused by uniformly extending a fixed time and ensures that containers in critical states are fully tested, further reducing the probability of misjudgment at the process level.

[0030] Furthermore, as the cumulative test duration approaches a preset value, the present invention gradually reduces the detection cycle (until the critical cycle) through an attenuation coefficient, thus matching the detection frequency with the stability requirements of the sealing state. In the initial stage of testing (far from the preset duration), the sealing state may still be changing; using a relatively long cycle can reduce unnecessary frequent detections. However, as the preset duration approaches, the state tends to stabilize, and shortening the cycle allows for more accurate capture of the final stable state, avoiding missing crucial data due to excessively long cycles. This ensures data validity while minimizing redundant detections and improving time utilization efficiency.

[0031] Furthermore, this invention effectively distinguishes between two types of non-compliance causes: "defects in the container itself" and "power deviation of the negative pressure device" by comparing the "difference between the absolute value of the difference and the second preset difference" with the "preset threshold". When the difference is less than the preset threshold, the container itself is determined to be non-compliant (excluding equipment factors); when the difference is greater than or equal to the preset threshold, it indicates that there may be an abnormal power in the negative pressure device. This classification logic avoids misjudging "equipment problems" as "container defects", or vice versa, making the location of non-compliance causes more accurate.

[0032] Furthermore, when the operating power changes due to historical deviation adjustments, the growth rate of the expected negative pressure change rate is adjusted accordingly. The higher the power, the greater the reduction in the rate of increase, making the overall system operation more stable and coordinated. By actively reducing the rate of increase of the expected negative pressure change rate (especially after power adjustment), the change in the expected value is made smoother and closer to the actual decay law of the container's sealing performance. This design avoids the problem of "amplified deviation between actual and expected values" caused by excessively rapid growth of the expected rate, reduces misjudgments caused by excessive fluctuations in the expected value, and further improves the accuracy of sealing performance determination. When the power is adjusted due to historical deviations, the rate of increase changes synchronously to adapt to the current operating state of the equipment. For containers with slow sealing performance decay, a smooth rate increase can reduce unnecessary judgment interventions. For containers in a critical state, reasonable rate control can more accurately capture their sealing change trend.

[0033] Furthermore, this invention re-evaluates the sealing performance after power adjustment. If it is still unqualified, it points to "the sealing problem at the interface between the negative pressure device and the pressure vessel," accurately pinpointing the problem to the critical connection link of the interface sealing, thus avoiding omissions due to ignoring interface issues. If the container is determined to be unqualified, equipment and interface factors have been ruled out, making the result more reliable. If the problem is confirmed to be an interface issue, it avoids misjudging the connection failure as a defect in the container itself. Attached Figure Description

[0034] Figure 1 This is a structural block diagram of the pressure vessel sealing structure performance testing equipment of the present invention;

[0035] Figure 2 Flowchart for determining whether the sealing performance of a pressure vessel meets the standards;

[0036] Figure 3 A flowchart for secondary determination of whether the sealing performance of a pressure vessel meets the standards;

[0037] Figure 4 A flowchart for determining the reasons why the sealing performance of the pressure vessel does not meet the standards. Detailed Implementation

[0038] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0039] It should be noted that the data in this embodiment are all derived from a comprehensive analysis and evaluation of historical data from the six months prior to this determination and the corresponding historical determination results by the system described in this invention. Those skilled in the art will understand that the system described in this invention can determine the above-mentioned parameters for a single item by selecting the value with the highest proportion based on the data distribution as the preset standard parameter, using weighted summation to obtain the value as the preset standard parameter, substituting each historical data point into a specific formula and using the value obtained by that formula as the preset standard parameter, or other selection methods, as long as the system described in this invention can clearly define different specific situations in the single-item determination process through the obtained values.

[0040] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0041] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0042] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Please see Figure 1 The diagram shown is a structural block diagram of the pressure vessel sealing structure performance testing equipment of the present invention.

[0044] This invention provides a pressure vessel sealing structure performance testing device. It includes:

[0045] A mounting device used for loading pressure vessels;

[0046] A negative pressure device is used to evacuate the pressure vessel. The negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power, and the negative pressure device increases its operating power during operation to increase the expected negative pressure change rate.

[0047] A detection device for periodically detecting the actual rate of change of negative pressure inside the pressure vessel;

[0048] An analysis module, connected to the detection device and the negative pressure device respectively, is used to acquire the actual negative pressure change rate detected by the detection device and the expected negative pressure change rate determined by the negative pressure device, and to determine whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and a preset ratio, and to determine the reason why the sealing performance of the pressure vessel does not meet the standard when the sealing performance of the pressure vessel does not meet the standard based on the absolute value of the difference.

[0049] Specifically, there are no restrictions on the specific structure of the analysis module; it can be composed of logic components, including field-programmable processors, computers, and microprocessors within computers.

[0050] Specifically, the negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power and the product of the reference negative pressure change rate.

[0051] In this embodiment of the invention, the expected negative pressure change rate is the product of the ratio of the current operating power of the negative pressure device to the rated operating power and the reference negative pressure change rate. The reference negative pressure change rate can be determined by the following method: using a leak-free standard container (e.g., a volume of 100L and a sealing level that meets the ASME V standard), an experiment is conducted in a constant temperature (25℃±1℃) and constant pressure (101.3kPa) environment. The negative pressure device is controlled to operate at different power levels, and the actual negative pressure change rate of the standard container is recorded. The rate under the rated power is obtained by linear fitting as the reference value. However, the above value is not limited to this, and those skilled in the art can adjust it according to the actual situation.

[0052] Please see Figure 2 As shown, it is a flowchart for determining whether the sealing performance of a pressure vessel meets the standard.

[0053] Specifically, the analysis module determines whether the pressure vessel's sealing performance meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate to the expected negative pressure change rate and a preset ratio.

[0054] If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is less than the first preset difference, then the sealing performance of the pressure vessel is determined to meet the standard.

[0055] If the absolute value of the difference between the ratio of negative pressure change rate and the preset ratio is greater than or equal to the first preset difference and less than the second preset difference, then it is determined whether the sealing performance of the pressure vessel meets the standard based on the cumulative test duration.

[0056] If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is greater than or equal to the second preset difference, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference.

[0057] In this embodiment of the invention, the preset ratio is set to 1. The first preset difference and the second preset difference can refer to the industry standard for pressure vessel sealing performance testing (such as GB / T26547 "Pressure Vessel Leakage Testing Method"). It is generally required that the actual negative pressure change rate of a qualified sealed container in vacuum testing should not deviate from the expected value by more than 10%-15%. Therefore, the first preset difference (preliminary qualified threshold) can be set as the lower limit of this range, and the second preset difference (unqualified threshold) can be set as the upper limit.

[0058] This invention determines the expected negative pressure change rate by multiplying the ratio of the current operating power to the rated power by the reference negative pressure change rate. This fully considers the differences in the actual operating state of the negative pressure device under different power levels, rather than relying solely on a fixed value at the rated power. It dynamically matches the device's real-time operating conditions, avoiding discrepancies between the expected value and the actual scenario caused by power fluctuations. A three-level judgment mechanism is employed to quickly identify clearly qualified or severely leaking situations, and to conduct secondary confirmation of ambiguous intermediate states through accumulated test time, avoiding misjudgments caused by instantaneous fluctuations. This layered processing balances detection efficiency and judgment accuracy, making it particularly suitable for scenarios with strict sealing requirements.

[0059] Please see Figure 3 As shown, it is a flowchart for determining whether the sealing performance of a pressure vessel meets the standard in a secondary judgment.

[0060] Specifically, the analysis module determines whether the pressure vessel's sealing performance meets the standards based on the cumulative test duration.

[0061] If the cumulative test duration is greater than or equal to the preset cumulative test duration, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference.

[0062] If the cumulative test duration is less than the preset cumulative test duration, then the corrected detection cycle is determined.

[0063] In this embodiment of the invention, the cumulative test time is the total test time accumulated from the start of the sealing performance test of the current pressure vessel by the testing equipment to the current moment. For example, if the sealing performance test of a certain pressure vessel starts at 9:00 AM and a second judgment is made at 9:30 AM, this 30-minute period is the cumulative test time at this moment. The preset cumulative test time can be determined by the following method. An excessively long preset time will reduce the testing efficiency (such as batch testing on a production line), while an excessively short time will affect the accuracy. By statistically analyzing historical testing data, the "shortest time required for 95% of qualified containers to achieve stable sealing status" is taken as the preset cumulative test time. However, the above value is not limited to this, and those skilled in the art can adjust it according to the actual situation.

[0064] The secondary judgment mechanism of this invention addresses the boundary situation where the absolute value of the difference is between the first and second preset differences. It introduces "cumulative test time" as a supplementary judgment criterion, preventing misjudgment due to insufficient testing time (when the sealing state is not yet stable) and avoiding over-testing of obviously unqualified containers. By controlling the maximum testing cycle through preset cumulative test time, the contradiction between "accuracy" and "efficiency" is effectively balanced. When the cumulative test time is insufficient, the "corrected testing cycle" (extended testing time) is used to allow the sealing state to fully stabilize before judgment, reducing misjudgments caused by instantaneous fluctuations or failure to reach a stable state. This dynamic adjustment mechanism makes the testing process more closely match the actual changing law of container sealing performance (such as the negative pressure state may gradually stabilize over time), further improving the reliability of the judgment results. For containers that are still in a boundary state after the cumulative test time reaches the target, they are directly judged as unqualified and the reasons are analyzed, ensuring strict control over potential leakage risks. This allows the test results to not only determine the state but also provide more accurate guidance for subsequent improvements.

[0065] Specifically, the analysis module adjusts the detection cycle based on the difference between the preset cumulative test duration and the actual cumulative test duration, and the increase in the detection cycle is positively correlated with the difference between the preset cumulative test duration and the actual cumulative test duration.

[0066] In this embodiment of the invention, the increase in the detection cycle is the product of a first proportional coefficient and the difference between the preset cumulative test duration and the actual cumulative test duration. The first proportional coefficient can be determined by selecting cases from past tests where "the cumulative test duration was insufficient during the second judgment," recording the preset cumulative test duration, actual cumulative test duration, initial detection cycle, the final result of passing / failing the second judgment, and the stability of the detection data under different cycle correction amounts. Through regression analysis, the proportional coefficient that makes the "second judgment accuracy the highest" is found, which is the first proportional coefficient. However, the above value is not limited to this, and those skilled in the art can adjust it according to the actual situation.

[0067] This invention transforms periodic correction into a quantifiable calculation process, avoiding subjective, experience-based adjustments. This linearly positively correlated correction logic (the larger the difference, the greater the increase) accurately matches the "extra time required for the sealed state to stabilize," making the extended detection cycle more aligned with the actual stabilization time needed by the container, reducing the problems of excessive extension or insufficient correction. The first proportional coefficient is determined through historical case statistics and regression analysis, with the accuracy of secondary judgment as the optimization objective. Typical cases of "insufficient cumulative time during secondary judgment" are selected for analysis to ensure that parameter optimization is based on pain points in real detection scenarios. The optimal coefficient is found through regression analysis, giving the correction mechanism a data-driven scientific basis and avoiding the blind setting of parameters. For cases of insufficient cumulative testing time, the detection cycle is extended in a targeted manner, giving containers whose sealed state has not yet stabilized sufficient "stabilization time," allowing subsequent judgments to be based on more reliable steady-state data. This avoids the inefficiency caused by uniformly extending a fixed time, while ensuring that containers in critical states are fully tested, further reducing the probability of misjudgment from a process perspective.

[0068] Specifically, the analysis module is based on the detection period after the attenuation coefficient is reduced and corrected.

[0069] In this embodiment of the invention, as the cumulative test duration increases (gradually approaching the preset cumulative test duration), the detection period T gradually decreases according to the attenuation coefficient until it reaches the critical period and then remains unchanged. The attenuation coefficient can be determined by the following methods: selecting test data of previously qualified containers, recording different attenuation coefficients, and determining whether the time for the period to decay to the critical value matches the preset cumulative duration; the stability of the test data (such as the standard deviation of the fluctuation of the negative pressure change rate); the accuracy of the final secondary judgment; by comparing the detection effects of different attenuation coefficients, the attenuation coefficient with "the highest data stability and judgment accuracy ≥ 95%" is selected as the attenuation coefficient for this test. However, the above values ​​are not limited to these, and those skilled in the art can adjust them according to the actual situation.

[0070] This invention gradually reduces the detection cycle (until the critical cycle) by using an attenuation coefficient as the cumulative test duration approaches a preset value, thus matching the detection frequency with the stability requirements of the sealing state. In the initial stage of testing (far from the preset duration), the sealing state may still be changing; using a relatively long cycle reduces unnecessary frequent detections. However, as the preset duration approaches, the state tends to stabilize, and shortening the cycle allows for more accurate capture of the final stable state, avoiding missing crucial data due to excessively long cycles. This approach maximizes data validity while minimizing redundant detections and improving time utilization efficiency.

[0071] Please see Figure 4 The diagram shown is a flowchart for determining the reasons why the sealing performance of the pressure vessel does not meet the standards.

[0072] Specifically, the analysis module determines the reason why the pressure vessel's sealing performance does not meet the standard based on the difference between the absolute value of the difference and a second preset difference.

[0073] If the difference between the absolute value of the difference and the second preset difference is less than a preset threshold, then the container is determined to be unqualified.

[0074] If the difference between the absolute value of the difference and the second preset difference is greater than or equal to the preset threshold, then a preset number of historical absolute values ​​of the difference are obtained, and the operating power of the negative pressure device at each node is adjusted according to the average value of each historical absolute value of the difference.

[0075] In this embodiment of the invention, the preset threshold can be determined by the following method: select samples known to be "qualified containers but with power deviations in the negative pressure device" (equipment abnormality samples) and record their distribution; select samples known to be "unqualified containers but with normal negative pressure devices" (container defect samples) and record their distribution; draw frequency histograms of the two types of samples, find the "separation point" of the two distributions, and take the lower limit of the 95% confidence interval of the separation point as the preset threshold.

[0076] This invention effectively distinguishes between two types of non-compliance causes: "defects in the container itself" and "power deviation of the negative pressure device" by comparing the "difference between the absolute value of the difference and the second preset difference" with a "preset threshold". When the difference is less than the preset threshold, the container itself is determined to be non-compliant (excluding equipment factors); when the difference is greater than or equal to the preset threshold, it indicates that there may be an abnormal power in the negative pressure device. This classification logic avoids misjudging "equipment problems" as "container defects", or vice versa, making the location of non-compliance causes more accurate.

[0077] Specifically, the analysis module adjusts the operating power of the negative pressure device at each node based on the average value of the absolute values ​​of each historical difference, and the increase in the operating power is negatively correlated with the average value of the absolute values ​​of each historical difference.

[0078] In this embodiment of the invention, the increase in power is the product of the second proportional coefficient and 1, and the ratio of the average of the absolute values ​​of the historical differences to the maximum average value. The maximum average value can be directly set according to the physical constraints of the system (such as the maximum allowable deviation of the negative pressure device, the sensor range, etc.). The second proportional coefficient can be determined by the following method: selecting past cases of "correcting deviation by adjusting power", recording the average of the absolute values ​​of the historical differences, the actual power adjustment range used in the corresponding cases, and the deviation improvement rate after adjustment, establishing a linear regression model, and fitting it with the least squares method to obtain the proportional coefficient that makes the "deviation improvement rate after adjustment the highest" as the second proportional coefficient.

[0079] Specifically, after the analysis module completes the analysis of the operating power of a single node, it reduces the rate of increase of the expected negative pressure change rate based on the adjusted operating power. The magnitude of the reduction in the rate of increase of the expected negative pressure change rate is positively correlated with the operating power.

[0080] In this embodiment of the invention, the reduction in the expected rate of increase of negative pressure change is the product of a third proportional coefficient and the operating power. The third proportional coefficient can be determined by the following method: selecting qualified cases of "reducing the rate of increase of negative pressure change by adjusting power", extracting the independent variables, dependent variables and the results of the adjusted sealing performance, establishing a linear regression model, and fitting the model using the least squares method to obtain the optimal proportional coefficient, so that the deviation between the model prediction value and the actual reduction is minimized; at the same time, ensuring that the fitted proportional coefficient satisfies that when the power is in the normal operating range, the increase of the rate of increase of negative pressure change can be stably controlled within the qualified range (e.g., the actual rate increase of more than 95% of cases is ≤ standard threshold), thus obtaining the third proportional coefficient.

[0081] This invention adjusts the rate of increase of the expected negative pressure change accordingly when the operating power changes due to historical deviation adjustments. The higher the power, the greater the reduction in the rate of increase, making the overall system operation more stable and coordinated. By actively reducing the rate of increase of the expected negative pressure change (especially after power adjustment), the change in the expected value is made smoother and closer to the actual decay law of the container's sealing performance. This design avoids the problem of "amplified deviation between actual and expected values" caused by excessively rapid growth of the expected rate, reduces misjudgments caused by excessive fluctuations in the expected value, and further improves the accuracy of sealing performance determination. When the power is adjusted due to historical deviations, the rate of increase changes synchronously to adapt to the current operating state of the equipment. For containers with slow sealing performance decay, a smooth rate increase can reduce unnecessary judgment interventions. For containers in a critical state, reasonable rate control can more accurately capture their sealing change trend.

[0082] Specifically, after the analysis module adjusts the operating power, it re-determines whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and the preset ratio. If the sealing performance of the pressure vessel still does not meet the standard, it determines that the reason is that the seal at the interface between the negative pressure device and the pressure vessel is unqualified, and issues a sealing inspection notice.

[0083] This invention re-evaluates the sealing performance after power adjustment. If it still fails, the problem is pinpointed to the "sealing issue at the interface between the negative pressure device and the pressure vessel," precisely identifying the problem at the critical connection point of the interface sealing. This avoids omissions due to overlooking interface issues. If the container is deemed unqualified, equipment and interface factors have been ruled out, making the result more reliable. If the problem is confirmed to be an interface issue, it avoids misjudging the connection failure as a defect in the container itself.

[0084] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure vessel sealing structure performance testing device, characterized in that, include: A mounting device used for loading pressure vessels; A negative pressure device is used to evacuate the pressure vessel. The negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power, and the negative pressure device increases its operating power during operation to increase the expected negative pressure change rate. A detection device for periodically detecting the actual rate of change of negative pressure inside the pressure vessel; An analysis module, connected to the detection device and the negative pressure device respectively, is used to acquire the actual negative pressure change rate detected by the detection device and the expected negative pressure change rate determined by the negative pressure device, and to determine whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and a preset ratio, and to determine the reason why the sealing performance of the pressure vessel does not meet the standard when the sealing performance of the pressure vessel does not meet the standard based on the absolute value of the difference. The negative pressure device determines the expected negative pressure change rate based on the ratio of the current operating power of the negative pressure device to the rated operating power and the product of the reference negative pressure change rate. The analysis module determines whether the pressure vessel's sealing performance meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate to the expected negative pressure change rate and a preset ratio. If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is less than the first preset difference, then the sealing performance of the pressure vessel is determined to meet the standard. If the absolute value of the difference between the ratio of negative pressure change rate and the preset ratio is greater than or equal to the first preset difference and less than the second preset difference, then it is determined whether the sealing performance of the pressure vessel meets the standard based on the cumulative test duration. If the absolute value of the difference between the ratio of negative pressure change rates and the preset ratio is greater than or equal to the second preset difference, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference. The analysis module determines whether the pressure vessel's sealing performance meets the standard based on the cumulative test duration. If the cumulative test duration is greater than or equal to the preset cumulative test duration, it is determined that the sealing performance of the pressure vessel does not meet the standard, and the reason for the non-compliance of the sealing performance of the pressure vessel is determined based on the difference between the absolute value of the difference and the second preset difference. If the cumulative test duration is less than the preset cumulative test duration, then the corrected detection cycle is determined.

2. The pressure vessel sealing structure performance testing equipment according to claim 1, characterized in that, The analysis module adjusts the detection cycle based on the difference between the preset cumulative test duration and the actual cumulative test duration. The increase in the detection cycle is positively correlated with the difference between the preset cumulative test duration and the actual cumulative test duration.

3. The pressure vessel sealing structure performance testing equipment according to claim 2, characterized in that, The analysis module is based on the detection period after the attenuation coefficient is reduced and corrected.

4. The pressure vessel sealing structure performance testing equipment according to claim 3, characterized in that, The analysis module determines the reason why the pressure vessel's sealing performance does not meet the standard based on the difference between the absolute value of the difference and a second preset difference. If the difference between the absolute value of the difference and the second preset difference is less than a preset threshold, then the container is determined to be unqualified. If the difference between the absolute value of the difference and the second preset difference is greater than or equal to the preset threshold, then a preset number of historical absolute values ​​of the difference are obtained, and the operating power of the negative pressure device at each node is adjusted according to the average value of each historical absolute value of the difference.

5. The pressure vessel sealing structure performance testing equipment according to claim 4, characterized in that, The analysis module adjusts the operating power of the negative pressure device at each node based on the average value of the absolute values ​​of the historical differences. The increase in the operating power is negatively correlated with the average value of the absolute values ​​of the historical differences.

6. The pressure vessel sealing structure performance testing equipment according to claim 5, characterized in that, After the analysis module completes the analysis of the operating power of a single node, it reduces the rate of increase of the expected negative pressure change rate based on the adjusted operating power. The magnitude of the reduction in the rate of increase of the expected negative pressure change rate is positively correlated with the operating power.

7. The pressure vessel sealing structure performance testing equipment according to claim 6, characterized in that, After the analysis module adjusts the operating power, it re-determines whether the sealing performance of the pressure vessel meets the standard based on the absolute value of the difference between the ratio of the actual negative pressure change rate and the expected negative pressure change rate and the preset ratio. If the sealing performance of the pressure vessel still does not meet the standard, it determines that the reason is that the seal at the interface between the negative pressure device and the pressure vessel is unqualified, and issues a sealing inspection notice.

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