A chemical raw material storage tank sealing performance detection method, device and system

Abstract

The present application relates to the technical field of sealing detection, and particularly relates to a chemical raw material storage tank sealing performance detection method, device and system, the method comprising: obtaining a pressure gradient sequence, a pressure difference sequence and a sound energy amplitude sequence in a relevant time period corresponding to a closing trigger moment of a breather valve; determining a time delay degree of the sound energy amplitude sequence according to the correlation between the pressure gradient sequence and the sound energy amplitude sequence after each translation, thereby inversely translating the sound energy amplitude sequence to obtain a sound energy amplitude correction sequence; generating a weight sequence according to the pressure difference sequence, thereby weighting and accumulating the sound energy amplitude correction sequence to obtain a sealing failure residual energy; and obtaining a chemical raw material storage tank sealing performance detection result according to the time delay degree and the sealing failure residual energy. The present application decouples the mixed acoustic signal into two independent features with clear physical meaning, thereby improving the accuracy of the chemical raw material storage tank sealing performance detection result.

Description

Technical Field

[0001] This invention relates to the field of sealing performance testing technology, specifically to a method, equipment, and system for testing the sealing performance of chemical raw material storage tanks. Background Technology

[0002] Chemical raw material storage tanks are typically equipped with breather valves to balance pressure fluctuations within the tank caused by feeding / discharging operations or changes in ambient temperature, ensuring tank safety. When handling volatile and easily polymerized / crystallized materials such as styrene and acrylic acid, the breather valve's sealing surface often malfunctions due to material deposits. These deposit-induced malfunctions mainly fall into two categories: first, viscous gel deposits, which increase the damping of the valve disc's movement, causing slow repositioning and time lag, but can usually be resolved through online cleaning; second, hard crystalline deposits, which accumulate between the valve disc and seat, preventing complete valve closure and resulting in continuous leakage, typically requiring disassembly, repair, or component replacement. Existing technologies for testing the sealing performance of chemical raw material storage tanks primarily rely on pressure sensors and acoustic sensors. Pressure sensors detect the pressure inside the tank, while acoustic sensors detect the acoustic signal at the breather valve. Conventional methods typically involve detecting the presence of an acoustic signal after the pressure has decreased. However, the acoustic signal during the pressure reduction process may originate from the trailing sound caused by sluggish valve operation (i.e., viscous fault) or from the leakage sound caused by incomplete valve closure (i.e., hard fault). Since these two types of sounds often overlap in the time domain, it is difficult to distinguish the nature of the fault, thus affecting the accuracy of the sealing performance test results of chemical raw material storage tanks. Summary of the Invention

[0003] To address the technical problem of low accuracy in testing the sealing performance of chemical raw material storage tanks, the present invention aims to provide a method, equipment, and system for testing the sealing performance of chemical raw material storage tanks. The specific technical solution adopted is as follows:

[0004] In a first aspect of the present invention, a method for testing the sealing performance of a chemical raw material storage tank is provided, comprising:

[0005] Obtain the pressure gradient sequence, pressure difference sequence, and acoustic energy amplitude sequence within the associated time period corresponding to the breathing valve closing trigger time; the pressure difference sequence represents the difference between the pressure amplitude and the breathing valve closing threshold.

[0006] The acoustic energy amplitude sequence is shifted several times in time, and the time delay of the acoustic energy amplitude sequence is determined based on the correlation between the pressure gradient sequence and the acoustic energy amplitude sequence after each shift.

[0007] From the shifted acoustic energy amplitude sequence corresponding to the aforementioned time delay, a corrected acoustic energy amplitude sequence is obtained;

[0008] The acoustic energy amplitude correction sequence is weighted and accumulated according to the weight sequence to obtain the residual energy of the sealing failure; the weight sequence is generated by the pressure difference sequence.

[0009] The sealing performance test results of chemical raw material storage tanks are obtained based on the degree of time delay and the residual energy of seal failure.

[0010] In an exemplary embodiment, the process of obtaining the degree of time delay includes:

[0011] Determine the maximum correlation among the correlations between the pressure gradient sequence and the acoustic energy amplitude sequence after each translation;

[0012] The shift magnitude corresponding to the maximum correlation is used as the time delay level.

[0013] In an exemplary embodiment, the process of obtaining the correlation includes:

[0014] Each time the acoustic energy amplitude sequence is shifted, the target acoustic energy amplitude sequence after each shift is determined; the target acoustic energy amplitude sequence is of the same length as the pressure gradient sequence.

[0015] The cross-correlation results between the pressure gradient sequence and the target acoustic energy amplitude sequence after each translation are obtained, and this is used as the correlation.

[0016] In an exemplary embodiment, the process of obtaining the weight sequence includes:

[0017] The weighting coefficient for each data point in the pressure difference sequence is obtained from the pressure difference value; the weighting coefficient is positively correlated with the pressure difference value.

[0018] The weight sequence is composed of the weight coefficients for each data point.

[0019] In an exemplary embodiment, obtaining the sealing performance test results of the chemical raw material storage tank based on the degree of time delay and the residual energy of seal failure includes:

[0020] If the time delay is less than or equal to a preset time delay threshold, and the residual energy of the seal failure is less than or equal to a preset residual energy threshold, then the sealing performance of the chemical raw material storage tank is determined to be normal.

[0021] If the time delay is greater than a preset time delay threshold and the residual energy of the seal failure is less than or equal to a preset residual energy threshold, then the sealing performance of the chemical raw material storage tank is determined to be abnormal, and the abnormality is caused by viscous adhesive damping.

[0022] If the residual energy of the seal failure is greater than the preset residual energy threshold for seal failure, the sealing performance of the chemical raw material storage tank is determined to be abnormal, and the abnormality is caused by hard particles blocking or physical damage.

[0023] In an exemplary embodiment, the process of obtaining the preset time delay threshold includes:

[0024] Obtain the time delay corresponding to the trigger times of multiple historical breathing valve closures;

[0025] Calculate the mean and standard deviation of the time delay corresponding to the multiple historical trigger times of the breathing valve closure, and use the sum of the mean and three times the standard deviation as the preset time delay threshold.

[0026] The process of obtaining the preset residual energy threshold for seal failure includes:

[0027] Obtain the residual energy of the seal failure corresponding to the trigger times of multiple historical breather valve closures;

[0028] Calculate the mean and standard deviation of the residual energy of the seal failure corresponding to the time of multiple historical breather valve closure triggers, and use the sum of the mean and 3 times the standard deviation as the preset residual energy threshold of the seal failure.

[0029] In one exemplary embodiment, the associated time period is a preset time range centered on the moment when the breathing valve closes.

[0030] In one exemplary embodiment, the acoustic amplitude sequence is obtained by removing ambient background noise from the original acoustic amplitude sequence.

[0031] In a second aspect of the invention, a chemical raw material storage tank sealing performance testing device is provided, comprising a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the above-described chemical raw material storage tank sealing performance testing method.

[0032] In a third aspect of the present invention, a sealing performance testing system for chemical raw material storage tanks is provided, comprising: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-described method for testing the sealing performance of chemical raw material storage tanks when the program instructions are executed.

[0033] This invention offers the following advantages: it locks in the critical time window for fault analysis (i.e., the associated time period corresponding to the trigger moment of the breathing valve closure) and acquires multi-dimensional synchronous data. The pressure gradient sequence characterizes the rate of pressure change and sensitively reflects the dynamic process of pressure change; the differential pressure sequence directly quantifies the difference between the pressure amplitude and the breathing valve closure threshold; and the acoustic energy amplitude sequence contains all the acoustic characteristics of the fault, providing a comprehensive and synchronous time-domain data foundation for subsequent detailed analysis. Since the acoustic signal generated by the valve disc action should be highly correlated with the pressure gradient signal under ideal, delay-free closure, and the acoustic signal will shift relative to the pressure change point when a delay occurs, the acoustic energy amplitude sequence is shifted several times in time, and the acoustic signal is compared with the dynamic pressure change process in the time domain. This quantitatively calculates the lag time (i.e., the degree of time delay) of the acoustic signal relative to the pressure change benchmark, thus clarifying the ambiguous issue of whether the valve action is slow. The malfunction phenomenon is transformed into a precisely measurable time parameter. After quantifying the delay time, the acoustic signal is aligned and corrected on the time axis, eliminating the interference caused by the delayed malfunction on the timing position of the acoustic signal. The resulting acoustic amplitude correction sequence is equivalent to aligning the actually observed acoustic signal, which may contain delays, to the theoretical valve closing time, eliminating interference. In the case of breather valve malfunction, it is mainly attributed to leakage, rather than the delayed closing action sound, creating conditions for the next step of evaluating the sealing performance test results. Based on the acoustic signal that has been stripped of delay interference, pressure difference is introduced as a weight for weighted accumulation, and finally the residual energy of sealing failure is obtained, reflecting the leakage duration, sound intensity, and leakage driving force, more accurately characterizing the severity of leakage-type faults. Finally, based on the degree of time delay and the residual energy of sealing failure, the sealing performance test results of the chemical raw material storage tank are obtained, realizing a dual-parameter, decoupled diagnosis of the breather valve sealing performance. Therefore, this invention decouples the mixed acoustic signal into two independent features with clear physical meaning, thereby improving the accuracy of the sealing performance test results of chemical raw material storage tanks. Attached Figure Description

[0034] Figure 1 This is a flowchart of the steps of a method for testing the sealing performance of a chemical raw material storage tank according to an embodiment of the present invention. Detailed Implementation

[0035] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. 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.

[0036] 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 invention pertains. All data and information collected in this application have been obtained with full consent.

[0037] This embodiment provides a method for testing the sealing performance of chemical raw material storage tanks, which is used to test the sealing performance of chemical raw material storage tanks.

[0038] This embodiment requires acquiring the pressure signal inside the chemical raw material storage tank and the acoustic energy signal from the breather valve. A pressure sensor is installed inside the chemical raw material storage tank to detect the pressure signal. An acoustic emission sensor is installed outside the chemical raw material storage tank, near the breather valve, to detect the acoustic energy signal from the breather valve. The specific value of the sampling frequency of the pressure sensor is set according to the actual detection needs; the higher the safety and real-time detection requirements, the higher the sampling frequency is set. This embodiment uses 10Hz as an example. The sampling frequency of the acoustic emission sensor can be the same as that of the pressure sensor and sample synchronously. In this embodiment, the sampling frequency of the acoustic emission sensor is set to meet the requirement of capturing millisecond-level delays, such as 50Hz. The collected data can be temporarily stored in a preset storage buffer for easy retrieval.

[0039] like Figure 1 As shown in the figure, the method for testing the sealing performance of a chemical raw material storage tank provided in this embodiment includes the following steps:

[0040] Step S1: Obtain the pressure gradient sequence, pressure difference sequence, and acoustic energy amplitude sequence within the associated time period corresponding to the breathing valve closing trigger moment;

[0041] Step S2: Shift the acoustic energy amplitude sequence several times in time, and determine the time delay of the acoustic energy amplitude sequence based on the correlation between the pressure gradient sequence and the acoustic energy amplitude sequence after each shift.

[0042] Step S3: Obtain the sound energy amplitude correction sequence from the shifted sound energy amplitude sequence corresponding to the time delay degree;

[0043] Step S4: Based on the weight sequence, perform weighted accumulation on the acoustic energy amplitude correction sequence to obtain the residual energy of the seal failure;

[0044] Step S5: Based on the time delay and residual energy of seal failure, obtain the test results of the sealing performance of the chemical raw material storage tank.

[0045] The following is a detailed explanation of each step.

[0046] Step S1: Obtain the pressure gradient sequence, pressure difference sequence, and acoustic energy amplitude sequence within the associated time period corresponding to the breathing valve closing trigger time.

[0047] First, the breather valve closing trigger time of the chemical raw material storage tank is determined. The breather valve closing trigger time characterizes the moment when the breather valve changes from an open state to a closed state. Since the breather valve may not close properly due to viscous deposits or hard crystal deposits, the closing trigger time cannot be directly obtained by detecting the open / closed state of the breather valve. This embodiment provides the following detection method: This embodiment presets a breather valve closing threshold, which is a set pressure amplitude. The breather valve closing threshold is an inherent parameter of the breather valve. Under normal circumstances, if the internal pressure of the chemical raw material storage tank is less than or equal to this breather valve closing threshold, the breather valve will close. Therefore, this embodiment acquires the internal pressure of the chemical raw material storage tank in real time according to a preset sampling frequency. When the pressure amplitude changes from greater than the breather valve closing threshold to less than or equal to the breather valve closing threshold (i.e., the rate of change of pressure amplitude is negative), a breather valve closing event is determined to have occurred. The moment when the pressure amplitude becomes less than or equal to the breather valve closing threshold is taken as the breather valve closing trigger time for this breather valve closing event.

[0048] For any given moment when the breathing valve closes, this embodiment uses the most recent moment as an example. The associated time period corresponding to the breathing valve closing trigger moment is determined. The associated time period is a critical time window related to the breathing valve closing trigger moment and relevant to fault analysis. In an exemplary embodiment, the associated time period is a preset time range centered on the breathing valve closing trigger moment. The length of the preset time range is set according to actual needs; for example, a preset time range of 30 seconds means that the time range centered on the breathing valve closing trigger moment includes the preceding and following 15 seconds.

[0049] Pressure sensors can acquire pressure amplitude values ​​at various times (i.e., at various sampling points, or data points). Based on the pressure amplitude values, the pressure gradient sequence and differential pressure sequence within the associated time period corresponding to the breathing valve closing trigger time can be obtained.

[0050] The pressure gradient sequence characterizes the degree of change in pressure amplitude between two adjacent moments. In an exemplary embodiment, the pressure amplitude within the associated time period is calculated using first-order difference to obtain the first-order difference value at each moment. The absolute values ​​of the first-order difference values ​​at each moment within the associated time period are then arranged chronologically to obtain the pressure gradient sequence within the associated time period. It should be understood that the first-order difference is used to obtain the degree of change between adjacent data. The pressure gradient sequence physically corresponds to the fluid velocity trend, and its waveform is pulse-like. Specifically:

[0051] ;

[0052] in, This represents the pressure gradient at the i-th time point (i.e., the i-th sampling point or the i-th data point) in the pressure gradient sequence. This represents the pressure amplitude at time i. This represents the pressure amplitude at time i-1.

[0053] The pressure difference sequence characterizes the difference between the pressure amplitude and the breathing valve closing threshold. In an exemplary embodiment, the breathing valve closing threshold is subtracted from the pressure amplitude at each time point, and the differences at each time point are sorted chronologically to obtain the pressure difference sequence within the associated time period. Specifically, when the pressure amplitude is less than the breathing valve closing threshold, the difference is positive; when the pressure amplitude is greater than the breathing valve closing threshold, the difference is negative; and when the pressure amplitude equals the breathing valve closing threshold, the difference is 0.

[0054] The acoustic energy amplitude values ​​at each moment within the associated time period are arranged chronologically to obtain the acoustic energy amplitude sequence for the associated time period. In this embodiment, the acoustic energy amplitude collected by the acoustic emission sensor is the original acoustic energy amplitude, which includes environmental background noise (such as continuous environmental noise from fans, pumps, etc. in the environment where the chemical raw material storage tank is located). The environmental background noise is removed from the original acoustic energy amplitude values ​​at each moment within the associated time period to obtain the acoustic energy amplitude values ​​at each moment, which are then arranged chronologically to obtain the acoustic energy amplitude sequence for the associated time period. After determining the environment where the chemical raw material storage tank is located, this embodiment can determine the acoustic energy amplitude corresponding to the environmental background noise, that is, the acoustic energy amplitude of the environmental background when the chemical raw material storage tank is shut down. In this embodiment, the acoustic energy amplitude corresponding to the environmental background noise can be set to a fixed value, which can be obtained experimentally or manually. The original acoustic energy amplitude values ​​at each moment are subtracted from this fixed value to obtain the acoustic energy amplitude values ​​at each moment.

[0055] Because ambient background noise varies with day and night or operating conditions, a fixed value may not accurately represent it. Therefore, in an exemplary embodiment, the dynamic ambient background noise reference acoustic amplitude can be obtained as follows: The original acoustic amplitude is acquired over a certain period before the breathing valve closes, for example, the original acoustic amplitude at various times within one hour. Then, the original acoustic amplitudes at various times within one hour are sorted from smallest to largest, and the top 5% of the original acoustic amplitudes are obtained (i.e., the lowest 5% of the original acoustic amplitudes). The average value of the top 5% of the original acoustic amplitudes is calculated, and the result is used as the dynamic ambient background noise reference acoustic amplitude related to the breathing valve closing trigger time. The physical significance of this process is that the lowest 5% of data typically corresponds to a quiet moment when the breathing valve is closed and there is no external transient interference. By statistically analyzing this data, the purest background noise level can be obtained, which can be used to remove ambient background interference from the original acoustic amplitude.

[0056] This embodiment can downsample the acoustic amplitude sequence to make its resolution completely consistent with the pressure gradient sequence and pressure difference sequence, both being 10Hz. By downsampling, the sampling frequencies of the pressure gradient sequence, pressure difference sequence, and acoustic amplitude sequence are synchronized, thereby ensuring that the lengths of the pressure gradient sequence, pressure difference sequence, and acoustic amplitude sequence within the associated time period corresponding to the breathing valve closing trigger moment are the same, and that the number of time points included is the same (i.e., the number of data points included is the same, or the number of sampling points included is the same).

[0057] It should be understood that in real-world scenarios, the breathing valve closing trigger time obtained through the above method may be caused by slight drift or electrical fluctuations in the pressure sensor, at which point the breathing valve may not actually be activated. To prevent false alarms caused by analyzing pure noise data, this embodiment requires energy prediction based on the acoustic amplitude: obtaining the maximum value of the original acoustic amplitude at each moment within the associated time period; if this maximum value is only slightly greater than the ambient background noise reference acoustic amplitude, or even less than or equal to the ambient background noise reference acoustic amplitude, then the breathing valve closing trigger time obtained at this time is determined to be invalid, and the data of the breathing valve closing trigger time and its corresponding associated time period are discarded, and no further data processing is performed, ensuring that subsequent data processing is only initiated when there is a significant energy change in the original acoustic amplitude that is significantly higher than the background noise. In an exemplary embodiment, the above judgment condition is specifically: the maximum value is less than the sum of the ambient background noise reference acoustic amplitude and a silence tolerance setting value, i.e. ,in, This represents the maximum value. This represents the reference sound energy amplitude of ambient background noise. This indicates the silent tolerance setting value. The specific value is set according to actual needs, for example, taking... 20%. As a preferred embodiment of the present invention, if the pressure drop gradient continuously set time tends to zero and the current pressure amplitude has not reached the breathing valve closing threshold, then the current moment is forcibly used as the breathing valve closing trigger moment, and the length of the continuously set time can be set by the implementer.

[0058] To facilitate subsequent processing, the pressure gradient sequence, pressure difference sequence, and acoustic amplitude sequence within the associated time period corresponding to the breathing valve closing trigger moment are normalized. This ensures that the data in these sequences are normalized and dimensionless. The pressure gradient sequence, pressure difference sequence, and acoustic amplitude sequence shown below are all normalized sequences. The normalization method can be maximum value normalization, as detailed below:

[0059] ;

[0060] in, This represents the normalized pressure gradient sequence. This represents the pressure gradient sequence before normalization. represents the maximum pressure gradient in the pressure gradient sequence before normalization, and n represents the number of moments within the associated time period.

[0061] ;

[0062] in, This represents the normalized pressure difference sequence. Indicates the breathing valve closing threshold. Represents a sequence of pressure amplitudes. Indicates taking If the maximum value between 0 and 1 is used, then when the pressure amplitude exceeds the breathing valve closing threshold, the difference is limited to 0. The closer the value is to 1, the lower the pressure inside the tank is to the breather valve closing threshold. At this point, the greater the reseating suction force on the valve disc of the breather valve, the more stringent the requirements for sealing. The differential pressure sequence waveform is usually S-shaped or stepped, used to define the time range within which sealing is required.

[0063] ;

[0064] in, This represents the normalized sequence of acoustic energy amplitudes. This represents the acoustic energy amplitude sequence before normalization (the acoustic energy amplitude sequence after removing environmental background noise). This represents the maximum acoustic energy amplitude gradient in the acoustic energy amplitude sequence before normalization. It can clearly characterize the relative sound intensity generated by the operation or leakage of the breather valve.

[0065] It should be understood that the above refers to the maximum pressure gradient in the pressure gradient sequence during normalization. Breathing valve closing threshold and the maximum acoustic amplitude gradient in the acoustic amplitude sequence. None of them can be 0; they are all values ​​greater than 0. Among them, the maximum pressure gradient in the pressure gradient sequence... The maximum acoustic energy amplitude gradient in the acoustic energy amplitude sequence If all values ​​are 0, the obtained breathing valve closing trigger time is determined to be invalid, and the obtained breathing valve closing trigger time is discarded without further data processing.

[0066] At this point, this step outputs three core sequences that are strictly aligned in time: representing the actual sound. Characterizing the trend of flow velocity and characterizing sealing requirements .

[0067] Step S2: Shift the acoustic energy amplitude sequence several times in time. Determine the time delay of the acoustic energy amplitude sequence based on the correlation between the pressure gradient sequence and the acoustic energy amplitude sequence after each shift.

[0068] In an ideal, delay-free closing scenario, the acoustic signal generated by the valve disc's actuation should be highly correlated with changes in the pressure signal. When a delay occurs, the acoustic signal shifts backward relative to the pressure change point. To quantify the lag time of the valve disc's actuation relative to the pressure change, this step utilizes sliding matching based on the correlation between sequences. In this step, a pressure gradient sequence is selected as the reference because it characterizes the theoretical flow velocity pulse and has a physical isomorphism with the envelope of the acoustic energy amplitude.

[0069] The acoustic energy amplitude sequence is shifted temporally several times. In an exemplary embodiment, this embodiment presupposes a shift amplitude range, which includes multiple shift amplitudes. The shift amplitude is essentially the number of moments, or the length of time. The shift amplitude range is... All data within the translation range are integers, meaning the translation range changes by one time increment. This is a preset negative translation amplitude value (e.g., 5 sampling points, meaning the maximum negative translation amplitude is 5) to tolerate sensor synchronization errors or minor lead responses. This is the preset maximum positive translation amplitude value (e.g., 50 sampling points, corresponding to the maximum allowable mechanical delay time, i.e., the maximum positive translation amplitude is 50).

[0070] In this embodiment, the order of translation amplitudes is determined by ascending the order of translation amplitudes. The length of the sliding window is used as the associated time period, and the sliding step size is used as the translation amplitude. When the translation amplitude is negative, the acoustic amplitude sequence slides forward in time (i.e., forward translation, indicating that the acoustic amplitude is ahead of the time period corresponding to the translation amplitude). When the translation amplitude is positive, the acoustic amplitude sequence slides backward in time (i.e., backward translation, indicating that the acoustic amplitude is behind the time period corresponding to the translation amplitude). Each time the acoustic amplitude sequence is translated, the resulting acoustic amplitude sequence is defined as the target acoustic amplitude sequence after each translation. The length of the target acoustic amplitude sequence after each translation is the same as that of the acoustic amplitude sequence and also the same as that of the pressure gradient sequence, both being associated time periods.

[0071] Taking a translation amplitude of m as an example, the target acoustic energy amplitude sequence obtained after this translation is determined. The correlation between the pressure gradient sequence and the target acoustic energy amplitude sequence obtained after this translation is obtained. In an exemplary embodiment, the correlation is specifically the cross-correlation result calculated using a cross-correlation function, and the calculation formula is as follows:

[0072] ;

[0073] in, Represents pressure gradient sequence The cross-correlation result between the target acoustic energy amplitude sequence obtained after this translation, i.e., the correlation; Represents pressure gradient sequence The pressure gradient at time i; This represents the target acoustic energy amplitude sequence obtained after the translation. The acoustic energy amplitude at the i-th time point, i.e., the acoustic energy amplitude sequence. The acoustic energy amplitude at time i is shifted by a shift amount m to obtain the acoustic energy amplitude at the corresponding time. It should be noted that if i+m exceeds the range of 1 to n, the acoustic energy amplitude of the current term... The value of is 0.

[0074] Product term The product represents the degree of overlap between two sequences at the same sampling point. The product is maximized when the peak values ​​of the waveforms corresponding to the two sequences appear at the same sampling point. The summation operation calculates the overall overlap over the entire time window. Therefore, the larger the calculated cross-correlation result, the higher the correlation between the actual acoustic energy amplitude sequence and the pressure gradient sequence, assuming a translation amplitude of m.

[0075] Iterate through all translation amplitudes within the range of translation amplitudes to obtain the cross-correlation results corresponding to each translation amplitude. The cross-correlation result with the highest value is taken as the maximum correlation. The translation amplitude corresponding to the maximum correlation is used as the time delay degree of the sound energy amplitude sequence, which can also be called the valve disc action delay index. If the time delay degree is equal to 0 or close to 0, it indicates that the sound pulse closely follows the pressure gradient pulse, the valve action is timely, and there is no adhesion. If the time delay degree is greater than 0, especially significantly greater than 0 (e.g., >10), it indicates that the sound pulse lags significantly behind the pressure change, suggesting that the viscous material hinders the valve disc movement, resulting in slow action. In an exemplary embodiment, to prevent misjudgment at the boundary, this embodiment can also perform a boundary check: if the calculated translation amplitude equals... If the obtained time delay is invalid (the signal may be incomplete or the delay may exceed the range), no result will be output.

[0076] Step S3: Obtain the sound energy amplitude correction sequence from the shifted sound energy amplitude sequence corresponding to the time delay degree.

[0077] After quantifying the lag time (i.e., the degree of time delay) of the acoustic energy amplitude sequence, this embodiment needs to eliminate the influence of this factor on subsequent leak detection. Therefore, the obtained degree of time delay is used to optimize the acoustic energy amplitude sequence. A reverse shift is performed to obtain the acoustic energy amplitude correction sequence. Specifically, the target acoustic energy amplitude sequence obtained after shifting according to the time delay (i.e., the target acoustic energy amplitude sequence corresponding to the maximum correlation mentioned above) is used as the acoustic energy amplitude correction sequence. .

[0078] The purpose of this step is to mathematically compensate for the time in the acoustic amplitude sequence. By shifting the lagging acoustic amplitude sequence forward by a time delay, the corrected acoustic amplitude sequence is made to represent an ideal operating scenario assuming the valve disc is not stuck and can respond instantaneously to pressure changes. At this point, the leading edge of the acoustic amplitude waveform in the corrected sequence is aligned with the start of the pressure change. This step is crucial for accurately calculating the leakage rate: only by eliminating the time difference caused by the lag can it be determined whether the remaining acoustic amplitude anomalies are due to a leak in the chemical raw material storage tank. Through this step, the viscous characteristics are successfully removed, and the aligned signal is output for subsequent analysis.

[0079] Step S4: Based on the weight sequence, perform weighted accumulation on the acoustic energy amplitude correction sequence to obtain the residual energy of the seal failure.

[0080] The sound of leakage from a chemical raw material storage tank is often similar to the sound of normal venting in the frequency domain, but they differ in their timing in the time domain: normal venting occurs during the pressure reduction process, while leakage sounds persist after the pressure reduction (i.e., when there is a large pressure difference). To distinguish between the two, this step utilizes a pressure difference sequence. A time-domain weighted mask is constructed, which is a weighted sequence for generating the acoustic energy amplitude correction sequence. In an exemplary embodiment, this is achieved using a pressure difference sequence. The pressure difference value at each time point is used to obtain the corresponding weighting coefficient, where the weighting coefficient is positively correlated with the pressure difference value. In an exemplary embodiment, an exponential weighting method is used to calculate the weighting coefficient at each time point:

[0081] ;

[0082] in, Represents the weight sequence The weight coefficient at time i. Represents pressure difference sequence The pressure difference value at time i is given by p, which represents the preset exponent (the recommended value range is 1.5 to 3.0, for example, 2). The function of the exponent p is to adjust the steepness of the transition zone. When p>1, it can suppress the value of the pressure difference in the transition zone between 0 and 1 (for example, the square of 0.5 equals 0.25), thereby strengthening the focus on the high pressure difference zone.

[0083] This represents the weight normalization function, specifically: obtaining the weights at each time point within the associated time period. The sum of , calculate the value at time i. The ratio of this sum to the weighted sequence is used as the weight sequence. The weighting coefficient at time i. Using this calculation method, while ensuring a positive correlation between the pressure difference value and the weighting coefficient, the sum of all weighting coefficients is equal to 1. The weighting coefficients at each time point are arranged in chronological order to form a weight sequence. .

[0084] It should be understood that the pressure difference sequence This characterizes the necessity of a seal. When the pressure amplitude inside the tank is much higher than the breather valve closing threshold, the pressure difference is close to 0; when the pressure amplitude inside the tank drops below the breather valve closing threshold, and the smaller the pressure amplitude inside the tank, the closer the pressure difference is to 1. The larger the weighting coefficient, the closer the tank is to a state that should be completely sealed at the corresponding moment. At this time, the sound energy amplitude is greater, and the probability of being judged as a leak is higher.

[0085] Based on the weighted sequence, the acoustic energy amplitude correction sequence is weighted and accumulated to obtain the residual energy of the seal failure:

[0086] ;

[0087] in, This indicates residual energy due to seal failure. Represents the acoustic energy amplitude correction sequence The amplitude of sound energy at the i-th time.

[0088] It should be understood that the acoustic energy contribution at each moment depends on the current sealing requirements: in the initial stage of breather valve closure, the pressure difference sequence When the pressure differential is small, the breather valve allows exhaust, and the weighting coefficient is close to 0. Even if there is a large exhaust sound or flow-induced noise (i.e., a large sound energy amplitude), its contribution to the residual energy of seal failure is greatly suppressed after being multiplied by the small weighting coefficient. This effectively eliminates the interference of normal operating sounds. In the later stage of breather valve closure, the pressure differential sequence... When the pressure difference is large, the valve breather should be completely closed. The weighting coefficient is large. If there is still residual sound energy (i.e., the sound energy amplitude is large, i.e. there is leakage sound), it will contribute more to the residual energy of the seal failure.

[0089] This step enables a precise definition of leakage: only those acoustic energy amplitudes occurring within a time period driven by high pressure differential and corrected for time alignment are identified as seal failure characteristics and quantified as residual energy of seal failure. This value directly reflects the severity of hard particle jamming or damage to the breather valve sealing surface, and is unrelated to viscous hysteresis.

[0090] Step S5: Based on the time delay and residual energy of seal failure, obtain the test results of the sealing performance of the chemical raw material storage tank.

[0091] The above steps yield two independent characteristics with clear physical meaning: the degree of time delay and the residual energy from seal failure. The degree of time delay characterizes the time lag in the breather valve's action, representing a viscous characteristic; the residual energy from seal failure characterizes the degree of leakage after the breather valve closes, representing a physical defect. Based on these two characteristics, the sealing performance of the chemical raw material storage tank is tested, and the test results are obtained.

[0092] This embodiment presets two thresholds: a time delay threshold and a residual energy threshold for sealing failure. The time delay is compared with the preset time delay threshold, and the residual energy for sealing failure is compared with the preset residual energy threshold for sealing failure.

[0093] If the time delay is less than or equal to the preset time delay threshold, and the residual energy of the seal failure is less than or equal to the preset residual energy threshold, it indicates that the breather valve operates in a timely manner and there is no obvious leakage after closing. Therefore, the sealing performance of the chemical raw material storage tank is determined to be normal, and an instruction that no operation is required and the equipment is healthy can be output.

[0094] If the time delay exceeds a preset time delay threshold, and the residual energy from seal failure is less than or equal to the preset residual energy threshold, it indicates that although the breather valve's action is significantly delayed (exceeding the allowable delay), it ultimately achieves an effective seal (low residual energy from seal failure). This suggests that the fault is caused solely by viscous adhesive damping, and the breather valve's sealing surface has not been damaged by hard materials. Therefore, it is determined that the chemical raw material storage tank's sealing performance is abnormal, and the abnormality is caused by viscous adhesive damping. The following instruction can be output: "The chemical raw material storage tank's sealing performance is abnormal, and the abnormality is caused by viscous adhesive damping." Workers can then perform online solvent cleaning or steam purging to remove the adhesive based on the output instruction.

[0095] If the residual energy from a seal failure exceeds the preset threshold, then regardless of the speed of the breather valve's operation (i.e., regardless of whether the time delay exceeds the preset threshold), significant residual acoustic energy will remain after the breather valve closes. This indicates that the breather valve's sealing surface is obstructed by hard particles or physically damaged and cannot recover on its own. Therefore, the chemical raw material storage tank's sealing performance is deemed abnormal, and the abnormality is caused by hard particle obstruction or physical damage. The following instruction can be output: "The chemical raw material storage tank's sealing performance is abnormal, and the abnormality is caused by hard particle obstruction or physical damage." Workers can then execute a shutdown, disassembly, repair, or replacement of the breather valve's disc gasket based on the output instruction.

[0096] The time delay threshold and the residual energy threshold for seal failure can be obtained in the laboratory or based on experience. However, fixed thresholds are difficult to adapt to individual differences in different devices. This embodiment adopts a statistically-based adaptive threshold setting strategy:

[0097] Regarding the threshold for time delay:

[0098] Obtain the time delay corresponding to the trigger times of multiple historical breathing valve closures, calculate the mean and standard deviation of the time delay corresponding to each historical breathing valve closure trigger time, and use the sum of the mean and three times the standard deviation as the preset time delay threshold:

[0099] ;

[0100] in, Indicates the threshold of time delay. This represents the average time delay corresponding to the trigger time of each historical breather valve closure. The standard deviation represents the time delay corresponding to the trigger time of each historical breather valve closure.

[0101] For the residual energy threshold of seal failure:

[0102] Obtain the residual energy of the seal failure corresponding to the trigger times of multiple historical breather valve closures; calculate the mean and standard deviation of the residual energy of the seal failure corresponding to each historical breather valve closure trigger time, and use the sum of the mean and three times the standard deviation as the preset threshold for residual energy of the seal failure.

[0103] ;

[0104] in, Indicates the residual energy threshold of seal failure. This represents the average residual energy threshold of the seal failure corresponding to each historical moment when the breather valve was closed. This represents the standard deviation of the residual energy threshold corresponding to the timing of each historical breather valve closure trigger.

[0105] The logic behind the threshold setting method described above is as follows: based on the 3σ principle of normal distribution, fluctuations under normal operating conditions have a high probability of falling within the threshold range (usually 99.7%). Once the real-time monitored value exceeds the threshold, there is a very high probability that an abnormal physical change has occurred (such as glue accumulation or hard damage), thereby triggering an alarm. This mechanism ensures the objectivity and specificity of the threshold setting, eliminating the need for manual guesswork based on experience.

[0106] In one exemplary embodiment, this embodiment also provides a chemical raw material storage tank sealing performance testing device, comprising: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the above-described chemical raw material storage tank sealing performance testing method embodiment.

[0107] In one exemplary embodiment, this embodiment also provides a chemical raw material storage tank sealing performance testing system, including: a memory and a processor; the memory is connected to the processor, and the memory is used to store program instructions; the processor is used to implement the steps in the above-described embodiment of the chemical raw material storage tank sealing performance testing method when the program instructions are executed.

[0108] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0109] 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.

Claims

1. A method for detecting the sealing performance of a chemical raw material storage tank, characterized by, include: Obtain the pressure gradient sequence, pressure difference sequence, and acoustic energy amplitude sequence within the associated time period corresponding to the breathing valve closing trigger moment; The differential pressure sequence characterizes the difference between the pressure amplitude and the breathing valve closing threshold. The acoustic amplitude sequence is shifted several times in time, and the time delay of the acoustic amplitude sequence is determined based on the correlation between the pressure gradient sequence and the acoustic amplitude sequence after each shift. This includes: determining the target acoustic amplitude sequence after each shift; the target acoustic amplitude sequence having the same length as the pressure gradient sequence; obtaining the cross-correlation result between the pressure gradient sequence and the target acoustic amplitude sequence after each shift, as the correlation; determining the maximum correlation among the correlations between the pressure gradient sequence and the acoustic amplitude sequence after each shift; and using the shift amplitude corresponding to the maximum correlation as the time delay. From the shifted acoustic energy amplitude sequence corresponding to the aforementioned time delay, a corrected acoustic energy amplitude sequence is obtained; According to the weight sequence, the acoustic energy amplitude correction sequence is weighted and accumulated to obtain the residual energy of the sealing failure; the weight sequence is generated by the pressure difference sequence, including: obtaining the weight coefficient of the corresponding data point from the pressure difference value of each data point in the pressure difference sequence; the weight coefficient is positively correlated with the pressure difference value; the weight sequence is composed of the weight coefficient of each data point; The sealing performance test results of the chemical raw material storage tank are obtained based on the degree of time delay and the residual energy of the seal failure, including: if the degree of time delay is less than or equal to a preset time delay threshold and the residual energy of the seal failure is less than or equal to a preset residual energy threshold, the sealing performance of the chemical raw material storage tank is determined to be normal; if the degree of time delay is greater than the preset time delay threshold and the residual energy of the seal failure is less than or equal to the preset residual energy threshold, the sealing performance of the chemical raw material storage tank is determined to be abnormal, and the abnormality is caused by viscous adhesive damping; if the residual energy of the seal failure is greater than the preset residual energy threshold, the sealing performance of the chemical raw material storage tank is determined to be abnormal, and the abnormality is caused by hard particle jamming or physical damage.

2. The method for testing the sealing performance of a chemical raw material storage tank as described in claim 1, characterized in that, The process of obtaining the preset time delay threshold includes: Obtain the time delay corresponding to the trigger times of multiple historical breathing valve closures; Calculate the mean and standard deviation of the time delay corresponding to the multiple historical trigger times of the breathing valve closure, and use the sum of the mean and three times the standard deviation as the preset time delay threshold. The process of obtaining the preset residual energy threshold for seal failure includes: Obtain the residual energy of the seal failure corresponding to the trigger times of multiple historical breather valve closures; Calculate the mean and standard deviation of the residual energy of the seal failure corresponding to the time of multiple historical breather valve closure triggers, and use the sum of the mean and 3 times the standard deviation as the preset residual energy threshold of the seal failure.

3. The method for testing the sealing performance of a chemical raw material storage tank as described in claim 1, characterized in that, The associated time period is a preset time range centered on the moment when the breathing valve closes.

4. The method for testing the sealing performance of a chemical raw material storage tank as described in claim 1, characterized in that, The acoustic energy amplitude sequence is obtained by removing environmental background noise from the original acoustic energy amplitude sequence.

5. A device for testing the sealing performance of chemical raw material storage tanks, characterized in that, The invention includes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the method for testing the sealing performance of a chemical raw material storage tank according to any one of claims 1-4.

6. A system for testing the sealing performance of chemical raw material storage tanks, characterized in that it comprises: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is used to implement the method for testing the sealing performance of chemical raw material storage tanks according to any one of claims 1-4 when program instructions are executed.

Images