Submersible sewage pump sealing test method and system based on coupling interface state recognition

Abstract

The invention provides a submersible sewage pump sealing testing method and system based on coupling interface state recognition, and relates to the technical field of mechanical sealing performance testing. According to the method, a disturbance applying unit is arranged on the water inlet side of the submersible sewage pump, disturbance is applied to excite a coupling interface to generate response change related to the sealing state, a response data collecting device is installed at the water inlet position close to the coupling end, response data related to the sealing performance are collected in real time, and a response change curve is generated; according to the method, multi-dimensional response features are extracted based on a curve, the coupling interface is divided into three states of close fitting, local clearance and loosening, a response feature range corresponding to each state is determined, and the current sealing state of the coupling interface is accurately recognized by comparing the response features with the response feature ranges. Real-time monitoring and early warning of the sealing state of the submersible sewage pump can be achieved, the problems of misjudgment and missing detection in a traditional method are effectively avoided, the detection precision and efficiency are improved, and the maintenance cost of the submersible sewage pump is reduced.

Description

Technical Field

[0001] This invention relates to the field of mechanical seal performance testing technology, specifically to a submersible sewage pump seal testing method and system based on coupling interface state identification. Background Technology

[0002] With the widespread application of pumps in industrial and municipal environments, submersible sewage pumps play a crucial role in sewage treatment, drainage systems, and other liquid transport systems. To ensure the normal operation of submersible sewage pumps and extend their service life, monitoring and evaluating their sealing performance is a critical step. Currently, submersible sewage pump sealing performance testing mainly relies on the following existing technologies: Vibration and temperature monitoring method: This method assesses sealing performance by installing sensors at different locations on the submersible pump to monitor pump body vibration and temperature changes. These signals are typically associated with the equipment's operating status, but are affected by internal noise and cannot directly reflect the sealing condition at the coupling interface, resulting in low accuracy and sensitivity.

[0003] Pressure change-based monitoring: This method assesses the sealing performance of a submersible pump by monitoring pressure fluctuations or changes during operation. While pressure changes can indicate potential seal failure, relying solely on pressure changes is insufficient to accurately determine the specific condition of the sealing interface.

[0004] Acoustic detection method: This method determines the operating status of a submersible sewage pump by detecting the acoustic signals generated by the pump body and coupling interface. Although acoustic signals provide some clues about sealing, the accuracy of the acoustic method is significantly affected by the noise environment and differences in the propagation characteristics of sound waves between equipment.

[0005] Therefore, existing technologies cannot provide sufficiently accurate sealing performance assessments in complex environments, nor can they achieve comprehensive, multi-dimensional state identification. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a method and system for testing the sealing of submersible sewage pumps based on coupling interface state recognition. By applying a disturbance to the inlet side of the submersible sewage pump, the coupling interface is stimulated to generate response changes related to its sealing state, and response data is acquired. By calculating the response characteristics of the coupling interface and comparing them with the standard response characteristic range, the current sealing state of the coupling interface is determined. This avoids the limitations of existing technologies and can provide a comprehensive and multi-dimensional assessment of sealing performance.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a method for testing the seal of a submersible sewage pump based on coupling interface state recognition, comprising the following steps: A disturbance application unit is set on the inlet side of the submersible sewage pump to apply a disturbance to the coupling interface to excite the interface response, so that the coupling interface produces a response change related to the interface state. A response data acquisition device is installed at the inlet of the submersible pump and near the coupling end. During the application of disturbance, the response data acquisition device collects response data related to the sealing performance of the coupling interface and calculates the response change curve based on the collected response data. Response characteristics reflecting the state of the coupling interface are obtained based on the response change curve. These response characteristics include amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics. The coupling interface is divided into a tight fit state, a local gap state, and a loose state. The corresponding response feature range is determined for each state, which serves as the basis for identifying the state of the coupling interface. The acquired response features are compared with the response feature range corresponding to each state to identify the current state of the coupled interface. Based on the current state of the coupling interface, determine the evaluation result of the sealing performance of the coupling interface.

[0008] To achieve the above objectives, another aspect of the present invention provides a submersible sewage pump sealing test system based on coupling interface state recognition, specifically including: The disturbance application module is used to apply disturbance to the inlet side of the submersible sewage pump, and to apply disturbance to the coupling interface to excite the interface response, so that the coupling interface produces a change corresponding to the interface state. The response data acquisition module is used to acquire response data related to the sealing performance of the coupling interface during the application of disturbance, and to calculate the response change curve based on the acquired response data. The response feature acquisition module is used to acquire response features reflecting the state of the coupling interface based on the response change curve. The response features include amplitude features, fluctuation features, steady-state time features, and decay features. The state determination module is used to divide the coupling interface into a tight fit state, a local gap state, and a loose state, and to determine the corresponding response feature range for each state as the basis for determining the state of the coupling interface. The state recognition module is used to compare the acquired response features with the response feature range corresponding to each state to identify the current state of the coupled interface. The evaluation module is used to determine the sealing performance evaluation result of the coupling interface based on the current state of the coupling interface.

[0009] One or more technical solutions provided in this invention have at least the following technical effects or advantages: This invention, through a submersible sewage pump sealing test method based on coupling interface state identification, can monitor the sealing performance of the submersible sewage pump in real time and accurately identify the sealing state of the coupling interface, thus avoiding the limitations of traditional detection methods. Specifically, by applying disturbance to the inlet side of the submersible pump, a response change is induced at the coupling interface, enabling a more sensitive and accurate response to changes in the sealing state. A response data acquisition device is positioned near the coupling end at the pump's inlet to collect real-time response data related to the sealing performance of the coupling interface and generate response change curves, providing reliable real-time data for sealing performance evaluation. Based on the response change curves, amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics reflecting the coupling interface state are obtained. These multi-dimensional response characteristics comprehensively reflect the sealing state of the coupling interface. The coupling interface is divided into tight fit, partial gap, and looseness states, and a corresponding response characteristic range is set for each state. Setting standard response characteristic ranges provides a strong basis for accurate identification of the sealing state. Comparing the acquired response characteristics with the response characteristic ranges corresponding to each state allows for precise identification of the current sealing state of the coupling interface, ensuring accurate and reliable evaluation results of sealing performance. Finally, based on the current state of the coupling interface, an accurate assessment of the sealing state is performed, promptly reflecting the sealing condition of the submersible pump and providing a scientific basis for subsequent maintenance. Compared with existing technologies, the technical solution of this invention breaks through the limitations of traditional detection methods, realizes all-round monitoring of the coupling interface state, and can promptly detect potential leakage risks through accurate state identification, providing reliable data support for the real-time operation and fault early warning of submersible pumps, and significantly reducing the failure rate and maintenance cost of equipment. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A schematic diagram of a submersible sewage pump sealing test method based on coupling interface state recognition is provided for an embodiment of this application; Figure 2 A schematic diagram of a submersible sewage pump sealing test system based on coupling interface state recognition is provided for an embodiment of this application; Explanation of reference numerals in the attached diagram: Disturbance application module 11, Response data acquisition module 12, Response feature acquisition module 13, State determination basis module 14, State identification module 15, Evaluation module 16. Detailed Implementation

[0012] This invention proposes a sealing test method for submersible sewage pumps based on coupling interface state recognition by introducing a coupling interface state recognition mechanism and multi-dimensional response feature analysis. By collecting and analyzing coupling interface response data in real time, it can accurately identify changes in sealing state, provide a more reliable and efficient sealing performance evaluation scheme, improve the operational safety and reliability of submersible sewage pumps, and reduce maintenance costs.

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0014] It should be noted that the terms "first," "second," etc., used in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, platform, product, or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products, or devices.

[0015] Example 1, as Figure 1 As shown, a method for testing the seal of a submersible sewage pump based on coupling interface state recognition includes the following steps: S1. A disturbance application unit is installed at the inlet of the submersible pump and near the coupling end to cause a response change at the coupling interface that is related to the interface state. Specifically, a disturbance application unit is installed at the inlet of the submersible sewage pump, near the coupling end, and connected to the pump's operation control system. This system includes at least an operation data processing unit for data acquisition and processing, a communication module for data transmission, and an output unit for feedback. The system controls the disturbance application unit to apply a disturbance to the coupling interface using preset disturbance parameters, thereby stimulating an interface response. This causes observable changes in the interface within a short time. The disturbance can be applied using pressure change disturbances, flow pulse disturbances, or sudden head change disturbances. While the transient responses caused by different disturbances vary, they all reflect differences in the interface state in the pressure change curve and flow change curve. The application of disturbances causes the coupling interface to exhibit response changes directly related to its state under different external conditions, providing a usable data foundation for subsequent response data acquisition and interface state identification. The pressure variation disturbance is applied by setting an adjustable pressure water source on the inlet side of the submersible sewage pump. The pump's operation control system adjusts the water source pressure according to preset pressure variation parameters, causing the pressure within the channel at the coupling interface to change within a set range. The pressure adjustment adopts a stepped pressure increase or decrease method, thereby stimulating the response differences of the coupling interface under different pressures. The flow pulse disturbance is applied by installing a controllable switch in the water supply path of the submersible sewage pump. The pump's operation control system controls the opening or closing of the controllable switch, causing a flow pulse in the water flow within a short period of time. The pulsed flow causes transient loads on the coupling interface, thereby inducing a flow response change related to the tightness of the coupling interface. The method of applying the head change disturbance is to adjust the operating conditions of the submersible sewage pump through the operation control system of the submersible sewage pump, change the head conditions in a short time, form a head change, and make the coupling interface bear the transient head difference. The head change causes the pressure and flow rate at the interface to change simultaneously.

[0016] S2. A response data acquisition device is installed at the inlet of the submersible pump and near the coupling end. During the application of disturbance, the response data acquisition device collects response data related to the sealing performance of the coupling interface, and calculates the response change curve based on the collected response data. Specifically, a response data acquisition device is installed at the inlet of the submersible sewage pump, near the coupling end. This device can be a pressure sensor or a flow meter. While a disturbance is applied to the coupling interface, the submersible sewage pump's operation control system coordinates and triggers the response data acquisition device to record the pressure value sequence at the pressure measuring point at the pump's inlet or the flow value sequence at the flow measuring point. This data serves as response data reflecting the sealing performance of the coupling interface. After acquisition, the collected data is arranged by time to generate a response change curve characterizing the response over time. Furthermore, the response change curve is either a pressure change curve or a flow rate change curve, where, The pressure change curve is obtained by acquiring the pressure change over time at the inlet of the submersible sewage pump using a pressure sensor. Specifically, a pressure measuring point is set at the inlet of the submersible sewage pump, near the coupling end, at a distance of 1-3 times the pipe diameter from the coupling end. A pressure sensor is placed at the pressure measuring point. The submersible sewage pump's operation control system synchronously triggers pressure data acquisition during the application of disturbance, and records the pressure change over time in real time during the disturbance application. The sampling frequency is set to 50-200 Hz, and the pressure value sequence {P(t0), P(t1), ..., P(t2)} arranged in chronological order is obtained. n )}, where P is the pressure value collected at the corresponding time point t, t is the time point corresponding to the disturbance process, and a pressure change curve is generated based on the pressure value sequence to reflect the pressure change process; The flow rate change curve is obtained by monitoring the flow rate change over time at the inlet of the submersible sewage pump using a flow meter. Specifically, a flow measurement point is set at the inlet of the submersible sewage pump, close to the coupling end, at a distance of 1-3 times the pipe diameter from the coupling end. A flow meter is placed at the flow measurement point. The submersible sewage pump's operation control system synchronously triggers flow data acquisition during the application of disturbance, and records the flow rate change over time in real time during the disturbance application process. The sampling frequency is set to 20-100 Hz, and a flow rate value sequence {Q(t0), Q(t1), ..., Q(t2)} arranged in chronological order is obtained. n )}, where Q is the flow rate value collected at the corresponding time point t, t is the corresponding time point during the disturbance process, and a flow rate change curve is generated based on the flow rate value sequence to reflect the flow rate change process.

[0017] S3. Obtain response characteristics reflecting the state of the coupling interface based on the response change curve. These response characteristics include amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics. Specifically, after the response change curve is generated, the submersible pump's operation control system processes the curve, extracting response characteristics reflecting the state of the coupling interface. These characteristics include: amplitude characteristics determined based on the amplitude changes of the pressure or flow rate curves; fluctuation characteristics determined based on the degree of fluctuation of the pressure or flow rate curves; steady-state time characteristics determined based on the time required for the pressure or flow rate curves to reach steady state; and attenuation characteristics determined based on the attenuation process of the pressure or flow rate curves. Furthermore, the acquisition of amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics specifically includes, S300. The amplitude characteristics are obtained by analyzing the maximum fluctuation of the response change curve relative to the average value sequence of the response value sequence before the disturbance, which is used to reflect the maximum response intensity caused by the disturbance. Specifically, firstly, pressure or flow rate sequences are collected over a period of time during the stable phase without disturbance, and the average value of these sequences is calculated as the average value of the response sequence during the stable phase before the disturbance. Then, during the disturbance, based on the collected pressure or flow rate sequences, the absolute value of the difference between the response value at each collection moment and the average value of the response sequence during the stable phase before the disturbance is calculated to obtain a fluctuation amplitude sequence that characterizes the instantaneous fluctuation degree of the disturbance. Finally, the maximum value is selected from the fluctuation amplitude sequence, and this maximum fluctuation amplitude is used as the amplitude feature to reflect the maximum response intensity caused by the disturbance. S301. Fluctuation characteristics are obtained by analyzing the overall fluctuation of the response change curve relative to the average value of the response value sequence before the disturbance, which is used to reflect the overall fluctuation of the response process. Specifically, during the disturbance application process, based on the collected pressure or flow rate sequence, the difference between the response value at each acquisition time and the average value of the response value sequence in the stable phase before the disturbance is calculated. The squares of each difference are summed, averaged, and the square root is taken to obtain a fluctuation metric value that characterizes the overall fluctuation level. This fluctuation metric value is used as a fluctuation feature to reflect the overall fluctuation of the response process. S302. By determining the time elapsed from the point when the response change curve deviates from the average value of the response value sequence in the stable phase before the disturbance to the point when it returns to the preset fluctuation range and remains stable, the steady-state time characteristic is obtained. This characteristic is used to define the time required for the response to recover to stability after the disturbance ends. Specifically, firstly, the time point t0 at which the pressure change curve or flow rate change curve begins to deviate from the average value of the response value sequence during the stable phase before the disturbance is obtained, which is taken as the start time of the disturbance. Then, during the disturbance application process, based on the collected pressure value sequence or flow rate value sequence, the absolute value of the difference between the response value at each collection time and the average value of the response value sequence during the stable phase before the disturbance is calculated to obtain a fluctuation amplitude sequence used to characterize the instantaneous fluctuation degree of the disturbance. When the fluctuation amplitude is continuously within the preset fluctuation amplitude range, it is determined that the response has recovered to a stable state. Next, the time point at which the pressure change curve or flow rate change curve re-enters and remains within the preset fluctuation amplitude range is recorded as t. s , as the moment of restoring a stable state; finally, by calculating t s The time difference between t0 and t0 is used to obtain the steady-state time feature T, which is used to limit the time required for the response to recover to stability after the disturbance ends. The preset fluctuation range is determined based on the natural fluctuation of the stable stage before the disturbance. Specifically, the response value sequence is collected over a period of time in the stable stage without disturbance, and the maximum fluctuation range Δmax of the sequence relative to the average value of the response value sequence in the stable stage before the disturbance is calculated. The preset fluctuation range is set as Δmax×k, where k is a fixed coefficient greater than 1, preferably 1.2. The preset fluctuation range determined in this way can reflect the steady-state noise level and ensure the stability and repeatability of the disturbance recovery judgment. S303. By determining the time elapsed from the occurrence of the maximum fluctuation amplitude of the response change curve relative to the average value sequence of the response value sequence before the disturbance, until that fluctuation amplitude decays to the fluctuation range corresponding to a preset proportion, the decay characteristic is obtained, which is used to characterize the rate at which the response deviation weakens over time. Specifically, first, the maximum fluctuation amplitude Δp of the response change curve relative to the average value sequence of the response value sequence before the disturbance is obtained, and the time point at which this maximum fluctuation amplitude occurs is taken as the starting time of the decay analysis, denoted as t. p Then, during the disturbance application process, based on the collected pressure or flow rate sequences, the fluctuation amplitude of the response value at each acquisition time relative to the average value of the response value sequence during the stable phase before the disturbance is calculated. The time point at which this fluctuation amplitude first falls into and remains within the upper limit of the attenuation target deviation range is recorded as... Finally, the time when the preset attenuation ratio is reached is calculated. The starting time t of the decay analysis p The time difference between them yields the attenuation characteristics. This is used to characterize the rate at which response fluctuations weaken over time. The upper limit of the attenuation target fluctuation range is determined by multiplying a preset attenuation ratio r by the maximum fluctuation amplitude Δp of the response change curve relative to the average value of the response value sequence in the stable phase before the disturbance, denoted as r×Δp. The attenuation ratio r is determined based on the natural fluctuation level in the stable phase before the disturbance. Specifically, the ratio of the maximum fluctuation amplitude Δmax of the response value sequence collected over a period of time in the stable phase without disturbance relative to the average value of the sequence to the maximum fluctuation amplitude Δp of the response change curve relative to the average value of the response value sequence in the stable phase before the disturbance is set as the attenuation ratio r, r=Δmax / Δp, to ensure that the attenuation target can reflect the actual degree of change in the attenuation process and avoid misjudgment caused by steady-state noise or small fluctuations.

[0018] S4. Divide the coupling interface into three states: tight fit, local gap, and looseness. Determine the corresponding response characteristic range for each state as the basis for identifying the coupling interface state. Specifically, based on the calibrated maximum allowable gap and minimum allowable sealing pressure at the coupling interface, the coupling interface is divided into a tight fit state, a partial gap state, and a loose state. Through multiple disturbance experiments under each state of the coupling interface, the values ​​of the response characteristics corresponding to each state are statistically analyzed, including the values ​​of amplitude characteristics, fluctuation characteristic range, steady-state time characteristic, and attenuation characteristic. Based on the range of response characteristic values ​​corresponding to the three states, the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the tight fit state, the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the partial gap state, and the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the loose state are determined. The data of the response characteristic ranges corresponding to each state are saved to a database associated with the operation and control process of the submersible sewage pump so that they can be called upon in subsequent coupling interface state identification as a basis for judgment.

[0019] Furthermore, the coupling interface is divided into three states: tight fit, local gap, and looseness, specifically including: Based on the maximum permissible gap calibrated at the coupling interface, the coupling interface is divided into a tightly fitted state and a non-tightly fitted state. Specifically, by obtaining the design tolerance range of the seal and the housing in the submersible pump design, the maximum allowable gap at the coupling interface can be determined. This data can be obtained directly from the product design parameters. According to the industry-recognized seal design principles, the maximum allowable gap determined during the manufacturing and assembly process of the seal is the critical assembly gap value that ensures effective contact between the seal and the housing and maintains sealing performance. Therefore, it can be used as the basis for judging whether the coupling interface is tightly fitted. Thus, the assembly state where the gap at the coupling interface is less than or equal to the maximum allowable gap is set as the tightly fitted state of the coupling interface, and the assembly state where the gap is greater than the maximum allowable gap is set as the non-tightly fitted state of the coupling interface. Based on the minimum permissible sealing pressure calibrated at the coupling interface, the non-tight fit state is further divided into a local gap state and a loose state. Specifically, since the product's calibrated gap parameters cannot be used as a reference to determine whether a submersible sewage pump is still in a sealed state, the rated minimum sealing pressure of the seal and housing designed in the product's design can be used as a reference. By obtaining the rated minimum sealing pressure of the seal and housing designed in the submersible sewage pump product, the minimum allowable sealing pressure at the coupling interface can be determined. This data can be obtained directly from the product design parameters. According to the industry-recognized seal design principles, the rated minimum sealing pressure corresponds to the critical contact pressure value required for the seal to achieve an effective seal at the coupling interface. Above this critical pressure, the seal can maintain sufficient contact stress to prevent media from seeping in or leaking. Therefore, it can be used as a criterion for determining whether the coupling interface is in a loose state when it is not in a tight fit. Therefore, the assembly state where the contact pressure at the coupling interface is less than or equal to the minimum allowable sealing pressure is set as the local gap state of the coupling interface, and the assembly state where the pressure is greater than the minimum allowable sealing pressure is set as the loose state of the coupling interface.

[0020] Furthermore, a corresponding range of response characteristics is determined for each state type, specifically including: Through multiple perturbation experiments under the close-fitting state, the values ​​of various response characteristics obtained from the multiple perturbation experiments were statistically analyzed, and the minimum and maximum values ​​of each response characteristic were determined as the response characteristic range corresponding to the close-fitting state. Specifically, multiple submersible sewage pumps of the same specifications were used as experimental samples. Disturbance experiments were conducted under standard operating conditions. For each sample, the gap between the sealing gasket's pressing surface and the shell plane was adjusted by adjusting the assembly amount of the sealing components. During adjustment, gap measuring tools, such as feeler gauges, coordinate measuring machines, or laser measuring instruments, were used to repeatedly measure the gap until it reached the maximum allowable gap at the coupling interface. At this point, the coupling interface of each sample was in a critical state of tight fit. Multiple disturbance experiments were conducted on each sample, and pressure or flow response data before and during the disturbance experiments were collected. The results were then calculated for each sample. The response characteristic data of this experiment were obtained by statistically analyzing the minimum and maximum values ​​of amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics obtained from all experimental samples and multiple experiments. These values ​​were then organized into intervals corresponding to each characteristic, which served as the response characteristic ranges corresponding to the close-fitting state. Specifically, the amplitude characteristic range corresponding to the close-fitting state was [A_min1, A_max1], the fluctuation characteristic range corresponding to the close-fitting state was [F_min1, F_max1], the steady-state time characteristic range corresponding to the close-fitting state was [W_min1, W_max1], and the decay characteristic range corresponding to the close-fitting state was [D_min1, D_max1].

[0021] Through multiple perturbation experiments of the local gap state, the values ​​of various response characteristics obtained from the multiple perturbation experiments are statistically analyzed, and the minimum and maximum values ​​of each response characteristic are determined as the response characteristic range corresponding to the local gap state. Specifically, in the test prototype, bolts were assembled at the coupling interface to obtain the actual axial load and interface clamping effect generated by the bolts under different torques. The axial load of the bolts corresponding to the minimum allowable sealing pressure at the coupling interface was determined. By recording the bolt tightening torque corresponding to this axial load, the bolt assembly torque value corresponding to the minimum allowable sealing pressure at the coupling interface was obtained. Multiple submersible sewage pumps of the same specifications were used as experimental samples, and disturbance experiments were conducted under standard operating conditions. For each experimental sample, the bolt torque was adjusted to reach the bolt assembly torque value corresponding to the minimum allowable sealing pressure at the coupling interface. At this point, the coupling interface of each experimental sample was in a critical state of local gap. Multiple disturbance experiments were conducted on each experimental sample, and the disturbance data were collected. The pressure or flow response data before and during the disturbance in the experiment were collected, and the response characteristic data of each experiment were calculated. The minimum and maximum values ​​of the amplitude characteristics, fluctuation characteristics, steady-state time characteristics and decay characteristics obtained from all experimental samples and multiple experiments were statistically analyzed and organized into intervals corresponding to each characteristic, which are used as the response characteristic ranges corresponding to the local gap state. That is: the amplitude characteristic range corresponding to the local gap state is [A_min2, A_max2], the fluctuation characteristic range corresponding to the local gap state is [F_min2, F_max2], the steady-state time characteristic range corresponding to the local gap state is [W_min2, W_max2], and the decay characteristic range corresponding to the local gap state is [D_min2, D_max2].

[0022] The range of characteristic values ​​greater than the upper limit of the response characteristic range corresponding to the local gap state is defined as the response characteristic range corresponding to the loose state. Specifically, since the upper limit of the response characteristic range corresponding to the local gap state is all data obtained from experimental samples assembled according to the bolt assembly torque value corresponding to the minimum allowable sealing pressure at the coupling interface, and the minimum allowable sealing pressure value at the coupling interface corresponds to the critical contact pressure value required for the seal to achieve effective sealing at the coupling interface, the upper limit of the response characteristic range corresponding to the local gap state can be selected as a reference to determine the response characteristic range corresponding to the loose state. Specifically, the upper limit of the amplitude characteristic range, the upper limit of the fluctuation characteristic range, the upper limit of the steady-state time characteristic range, and the upper limit of the attenuation characteristic range corresponding to the local gap state are respectively used as the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the loose state. That is, the amplitude characteristic range corresponding to the loose state is (A_max2, ∞), the fluctuation characteristic range corresponding to the loose state is (F_max2, ∞), the steady-state time characteristic range corresponding to the loose state is (W_max2, ∞), and the attenuation characteristic range corresponding to the loose state is (D_max2, ∞).

[0023] S5. Compare the acquired response features with the response feature range corresponding to each state type to identify the current state of the coupled interface. Furthermore, identifying the current state of the coupling interface specifically includes, If all the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics fall within the response characteristic range corresponding to the closely fitted state of each characteristic, then the coupling interface is determined to be in a closely fitted state. If at least one of the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics does not fall within the response characteristic range corresponding to the close fit state of each characteristic, and all of them do not exceed the response characteristic range corresponding to the local gap state of each characteristic, then the coupling interface is determined to be in a local gap state. If any of the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics falls within the response characteristic range corresponding to the loose state of each characteristic, then the coupling interface is determined to be in a loose state.

[0024] Specifically, based on the amplitude, fluctuation, steady-state time, and decay characteristics of the disturbance applied to the coupling interface to excite the interface response, and by calling the response characteristic range corresponding to each state stored in the database associated with the submersible pump operation control process, the amplitude characteristics are compared with the amplitude characteristic range corresponding to each state, the fluctuation characteristics are compared with the fluctuation characteristic range corresponding to each state, the steady-state time characteristics are compared with the steady-state time characteristic range corresponding to each state, and the decay characteristics are compared with the decay characteristic range corresponding to each state. When the acquired amplitude, fluctuation, steady-state time, and decay characteristics fall into the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and decay characteristic range corresponding to the closely fitted state, respectively, it can be determined that at the coupling interface... In a tightly fitted state, if at least one of the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics does not fall within the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, or attenuation characteristic range corresponding to the tightly fitted state, and all acquired characteristic data does not exceed the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the local gap state, then the coupling interface can be determined to be in a local gap state. If any one of the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and attenuation characteristics falls within the amplitude characteristic range, fluctuation characteristic range, steady-state time characteristic range, and attenuation characteristic range corresponding to the loose state, then the coupling interface is determined to be in a loose state. Finally, the determination result is recorded in the database associated with the submersible pump operation control process.

[0025] S6. Based on the current state of the coupling interface, determine the evaluation result of the sealing performance of the coupling interface. Specifically, if the coupling interface is determined to be in a tightly fitted state, the sealing performance in this state is deemed qualified, indicating that the coupling interface has achieved the expected sealing effect and can effectively prevent leakage. If the coupling interface is in a state of partial gap, the sealing performance in this state is deemed to be pending verification, and there may be a certain risk of leakage, but it can still be used for a certain period of time. If the coupling interface is determined to be in a loose state, the sealing performance in this state is deemed unqualified, meaning that the sealing performance has failed and there is a significant risk of leakage. Immediate repair measures or replacement of relevant seals are required. Based on the sealing performance evaluation results, the submersible pump's operation control system will trigger corresponding output feedback.

[0026] Example 2 is based on the same inventive concept as the submersible sewage pump sealing test method based on coupling interface state recognition in the previous examples, such as... Figure 2 As shown, this application provides a submersible pump seal testing system based on coupling interface state recognition. The system and method embodiments in this application are based on the same inventive concept. The system includes: The disturbance application module is used to apply disturbance to the inlet side of the submersible pump, and to apply disturbance to the coupling interface to excite the interface response, so that the coupling interface produces a change corresponding to the interface state. The response data acquisition module is used to acquire response data related to the sealing performance of the coupling interface during the application of disturbance, and to calculate the response change curve based on the acquired response data. The response feature acquisition module is used to acquire response features reflecting the state of the coupling interface based on the response change curve. The response features include amplitude features, fluctuation features, steady-state time features, and decay features. The state determination module is used to divide the coupling interface into a tight fit state, a local gap state, and a loose state, and to determine the corresponding response feature range for each state as the basis for determining the state of the coupling interface. The state recognition module is used to compare the acquired response features with the response feature range corresponding to each state to identify the current state of the coupled interface. The evaluation module is used to determine the sealing performance evaluation result of the coupling interface based on the current state of the coupling interface.

[0027] Although this application makes various references to certain modules in the system according to the embodiments of this application, any number of different modules can be used and run on user terminals and / or servers. The various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy distinction between each other and are not used to limit the scope of protection of this invention.

[0028] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for testing the seal of a submersible sewage pump based on coupling interface state recognition, characterized in that, Includes the following steps, A disturbance application unit is set on the inlet side of the submersible sewage pump to apply a disturbance to the coupling interface to excite the interface response, so that the coupling interface produces a response change related to the interface state. A response data acquisition device is installed at the inlet of the submersible pump and near the coupling end. During the application of disturbance, the response data acquisition device collects response data related to the sealing performance of the coupling interface and calculates the response change curve based on the collected response data. Response characteristics reflecting the state of the coupling interface are obtained based on the response change curve. These response characteristics include amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics. The coupling interface is divided into a tight fit state, a local gap state, and a loose state. The corresponding response feature range is determined for each state, which serves as the basis for identifying the state of the coupling interface. The acquired response features are compared with the response feature range corresponding to each state to identify the current state of the coupled interface. Based on the current state of the coupling interface, determine the evaluation result of the sealing performance of the coupling interface.

2. The submersible pump sealing test method according to claim 1, characterized in that, The response change curve is either a pressure change curve or a flow rate change curve. The pressure change curve is obtained by acquiring the pressure change at the inlet of the submersible pump over time using a pressure sensor. The flow rate change curve is obtained by monitoring the flow rate change at the inlet of the submersible pump over time using a flow meter.

3. The submersible pump sealing test method according to claim 2, characterized in that, The acquisition of the amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics specifically includes, The amplitude characteristics are obtained by analyzing the maximum fluctuation of the response change curve relative to the average value of the response value sequence before the disturbance, which is used to reflect the maximum response intensity caused by the disturbance. The fluctuation characteristics are obtained by analyzing the overall fluctuation of the response change curve relative to the average value of the response value sequence before the disturbance, which is used to reflect the overall fluctuation of the response process. The steady-state time characteristic is obtained by determining the time taken from the point when the response change curve deviates from the average value of the response value sequence in the stable phase before the disturbance to the point when it returns to the preset fluctuation range and remains stable. This characteristic is used to limit the time required for the response to recover to stability after the disturbance ends. The decay characteristic is obtained by determining the time taken from the occurrence of the maximum fluctuation amplitude of the response change curve relative to the average value of the response value sequence before the disturbance to the decay amplitude decaying to the fluctuation range corresponding to a preset proportion. This characteristic is used to characterize the speed at which the response deviation weakens over time.

4. The submersible pump sealing test method according to claim 3, characterized in that, The coupling interface is divided into a tightly fitted state, a partially gapped state, and a loose state, specifically including: Based on the maximum allowable gap calibrated at the coupling interface, the coupling interface is divided into a tightly fitted state and a non-tightly fitted state. Based on the minimum permissible sealing pressure calibrated at the coupling interface, the non-tightly fitted state is further divided into a local gap state and a loose state.

5. The submersible pump sealing test method according to claim 4, characterized in that, The process of determining the corresponding response feature range for each state type specifically includes: Through multiple perturbation experiments in a tightly fitted state, the values ​​of various response characteristics obtained from the multiple perturbation experiments were statistically analyzed, and the minimum and maximum values ​​of each response characteristic were determined as the response characteristic range corresponding to the tightly fitted state. Through multiple perturbation experiments of the local gap state, the values ​​of various response characteristics obtained from the multiple perturbation experiments are statistically analyzed, and the minimum and maximum values ​​of each response characteristic are determined as the response characteristic range corresponding to the local gap state. The range of characteristic values ​​that are greater than the upper limit of the response characteristic range corresponding to the local gap state is defined as the response characteristic range corresponding to the loose state.

6. The submersible pump sealing test method according to claim 5, characterized in that, The current state of the identification coupling interface specifically includes, If all the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics fall within the response characteristic range corresponding to the closely fitted state of each characteristic, then the coupling interface is determined to be in a closely fitted state. If at least one of the acquired amplitude characteristics, fluctuation characteristics, steady-state time characteristics, and decay characteristics does not fall within the response characteristic range corresponding to the close fit state of each characteristic, and all of them do not exceed the response characteristic range corresponding to the local gap state of each characteristic, then the coupling interface is determined to be in a local gap state. If any one of the acquired amplitude feature, fluctuation feature, steady-state time feature, and decay feature data falls within the response feature range corresponding to the loose state of each feature, then the coupling interface is determined to be in a loose state.

7. A submersible sewage pump seal testing system based on coupling interface state recognition, characterized in that, The steps for implementing the submersible sewage pump seal testing method based on coupling interface state recognition according to any one of claims 1 to 6, wherein the submersible sewage pump seal testing system based on coupling interface state recognition includes, The disturbance application module is used to apply disturbance to the inlet side of the submersible pump, and to apply disturbance to the coupling interface to excite the interface response, so that the coupling interface produces a change corresponding to the interface state. The response data acquisition module is used to acquire response data related to the sealing performance of the coupling interface during the application of disturbance, and to calculate the response change curve based on the acquired response data. The response feature acquisition module is used to acquire response features reflecting the state of the coupling interface based on the response change curve. The response features include amplitude features, fluctuation features, steady-state time features, and decay features. The state determination module is used to divide the coupling interface into a tight fit state, a local gap state, and a loose state, and to determine the corresponding response feature range for each state as the basis for determining the state of the coupling interface. The state recognition module is used to compare the acquired response features with the response feature range corresponding to each state to identify the current state of the coupled interface. The evaluation module is used to determine the sealing performance evaluation result of the coupling interface based on the current state of the coupling interface.

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