A sewage valve opening fluctuation diagnosis method and system

Abstract

The application discloses a sewage valve opening fluctuation diagnosis method and system, and belongs to the technical field of sewage treatment equipment operation monitoring. The method obtains an opening instruction sequence, an actual opening feedback sequence, a pressure difference sequence before and after the valve, and a valve flow sequence in a one-time opening adjustment process of a sewage valve, determines an adjustment direction according to the opening instruction sequence, and identifies a pause section, a jump section and a response lag amount according to a following difference value between the actual opening feedback sequence and the opening instruction sequence. The opening abnormality, the pressure difference and the flow data are time-aligned to obtain a pressure difference disturbance amount and a flow recovery amount. When the two satisfy corresponding conditions, a candidate foreign matter blockage event is marked, and a repeated lag amount is calculated under a subsequent same adjustment direction, so that a foreign matter instantaneous blockage diagnosis result or an actuator aging diagnosis result is output.

Description

Technical Field

[0001] This application belongs to the field of sewage treatment equipment operation monitoring technology, specifically a sewage valve opening fluctuation diagnosis method and system. Background Technology

[0002] Wastewater treatment plants, wastewater pumping stations, and industrial wastewater pretreatment stations typically install electric or pneumatic valves to regulate influent flow, sludge return volume, sludge discharge volume, bypass flow, or chemical dosage. Current valve operation monitoring methods generally determine valve malfunctions based on opening commands, actual opening feedback, arrival signals, or response times. When the actual opening lags, pauses, jumps, or deviates from the opening command, without a correlation analysis of the wastewater flow status, such anomalies are easily attributed to valve malfunctions such as insufficient actuator torque, gear wear, valve stem jamming, positioner misalignment, or increased packing friction.

[0003] However, wastewater differs from clean water. Urban sewage and mixed industrial wastewater often contain impurities such as wet wipes, plastic flakes, fiber bundles, silt clumps, and grease. When a valve is in a partially open adjustment state, these impurities may become stuck briefly on the valve plate edge, in the valve seat gap, or in the valve core flow channel, causing a brief pause, slow response, or abrupt opening changes during the valve's opening or closing process. Once the impurities are washed away by the subsequent water flow, the valve may return to normal. This type of momentary jamming exhibits similar characteristics on the opening feedback curve to chronic hysteresis caused by actuator aging, increased transmission clearance, or decreased output torque. Existing diagnostic methods, which rely solely on a single opening response delay or a single opening abrupt change for alarm purposes, cannot distinguish between momentary jamming caused by sewage impurities and actuator aging.

[0004] For example, when adjusting the inlet regulating valve from 30% to 40%, the actual opening feedback may pause for a few seconds around 34% before suddenly jumping to 39%. This could be due to sewage debris being briefly trapped and then washed away by the water flow, or it could be caused by a decrease in the output capacity of the actuator or degradation of the transmission components, resulting in lag. Conversely, if similar lag or jump phenomena occur repeatedly in subsequent operation, it is more likely related to aging of the actuator, increased transmission clearance, or decreased output torque. If these two types of causes cannot be effectively distinguished, on the one hand, short-term debris disturbances may be misjudged as valve hardware failures, leading to unnecessary disassembly and inspection; on the other hand, persistent mechanical degradation may be mistaken for sewage debris interference, delaying maintenance and ultimately causing valve refusal to operate, regulation failure, or uncontrolled flow in the sewage treatment process.

[0005] Therefore, in the existing diagnosis of sewage valve opening fluctuations, it is urgent to solve the problem of how to distinguish between the instantaneous blockage of sewage debris and the aging of the actuator when there is a pause, jump or lag in the opening feedback. Summary of the Invention

[0006] To address the problem that existing sewage valve operation monitoring methods rely solely on opening commands, actual opening feedback, arrival signals, or response times to determine valve anomalies, making it difficult to distinguish between momentary blockage by sewage debris and aging actuators, this application provides a sewage valve opening fluctuation diagnosis method and system. This method correlates abnormal opening feedback during a single opening adjustment process with pressure differential disturbances before and after the valve, flow recovery, and subsequent repetitive hysteresis in the same adjustment direction. This reduces the likelihood of misjudging short-term debris disturbances as actuator malfunctions and lowers the risk of mistaking continuous mechanical degradation for sewage debris interference.

[0007] To achieve the above objectives, this application adopts the following technical solution.

[0008] Firstly, this application provides a method for diagnosing fluctuations in the opening degree of a sewage valve, including: The system acquires the opening command sequence, actual opening feedback sequence, valve inlet and outlet pressure difference sequence, and flow rate sequence of the sewage valve during a single opening adjustment process, and determines the adjustment direction of the sewage valve based on the opening command sequence. Based on the following difference between the actual opening feedback sequence and the opening command sequence, the pause segment, jump segment and response hysteresis in the actual opening feedback sequence are identified; The pause segment, the jump segment, and the response hysteresis are time-aligned with the valve pre-valve and post-valve differential pressure sequence and the valve flow sequence to obtain the synchronously occurring differential pressure disturbance and flow recovery. When the differential pressure disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition, the current opening adjustment process is marked as a candidate debris jamming event. After the candidate debris jamming event, the subsequent opening adjustment process under the same adjustment direction is extracted, and the repetition hysteresis of the subsequent opening adjustment process is calculated. If the repetition hysteresis is less than the preset repetition threshold, the instantaneous obstruction diagnosis result of the debris is output. If the repetitive hysteresis is not less than the preset repetition threshold, then the aging diagnosis result of the actuator is output.

[0009] In one possible implementation, determining the adjustment direction of the sewage valve based on the opening command sequence includes: taking the opening command value at the start of adjustment in the opening command sequence as the initial command opening; taking the opening command value corresponding to when the actual opening feedback value enters the target opening allowable deviation range and remains stable for a preset time as the target command opening; when the target command opening is greater than the initial command opening, marking the adjustment direction as the opening direction; when the target command opening is less than the initial command opening, marking the adjustment direction as the closing direction; and storing the adjustment direction in association with the current opening adjustment process.

[0010] In one possible implementation, based on the following difference between the actual opening feedback sequence and the opening command sequence, the pause segments, jump segments, and response hysteresis in the actual opening feedback sequence are identified, including: calculating the absolute difference between the actual opening feedback value and the opening command value at each sampling time to obtain a following difference sequence; identifying the sampling interval where the continuous change in the actual opening feedback value is less than a preset pause change threshold and the duration is not less than a preset pause duration threshold as a pause segment; identifying the sampling interval where the change in the actual opening feedback value at adjacent sampling times is not less than a preset jump threshold as a jump segment; and using the maximum value or the average value within a preset time window in the following difference sequence as the response hysteresis.

[0011] In one possible implementation, obtaining the synchronously occurring differential pressure disturbance and flow recovery includes: using the start and end sampling times corresponding to the pause segment and the jump segment, and the sampling time of the maximum following difference corresponding to the response hysteresis or the response hysteresis window as an abnormal window, extending a preset alignment time before and after the abnormal window respectively to obtain a differential pressure-flow alignment window; reading the differential pressure value before and after the valve and the flow rate value through the valve within the differential pressure-flow alignment window, taking the maximum deviation of the differential pressure within the abnormal window as the differential pressure disturbance, and taking the flow recovery amplitude after the abnormal window ends as the flow recovery amount.

[0012] In one possible implementation, the preset clamping disturbance condition includes a differential pressure disturbance amplitude condition and a differential pressure disturbance timing condition; the differential pressure disturbance amplitude condition is that the differential pressure disturbance amount is not less than a preset differential pressure disturbance threshold; the differential pressure disturbance timing condition is that the peak time of the differential pressure disturbance is located within the pause segment, the jump segment, or an adjacent extended time window of the pause segment and the jump segment.

[0013] In one possible implementation, the preset flushing recovery condition includes a flow recovery magnitude condition and a recovery time condition; the flow recovery magnitude condition is that the flow recovery amount is not less than a preset flow recovery threshold; the recovery time condition is that the over-valve flow value returns to the preset flow allowable range corresponding to the target opening within a preset recovery time after the end of the pause or the jump section.

[0014] In one possible implementation, calculating the repetitive hysteresis of the subsequent opening adjustment process includes: reading the abnormal opening interval corresponding to the candidate debris jamming event, wherein the abnormal opening interval is determined by the minimum and maximum values ​​of the actual opening feedback values ​​within the pause segment and the jump segment; during the subsequent opening adjustment process in the same adjustment direction, intercepting the sampling interval falling within the abnormal opening interval and its preset opening tolerance range; calculating the maximum following difference and the pause duration within the sampling interval respectively, and converting the two into the repetitive hysteresis according to a preset hysteresis conversion rule.

[0015] In one possible implementation, after the candidate debris jamming event, if no subsequent opening adjustment process under the same adjustment direction is extracted within a preset review period, the candidate debris jamming event is marked as a review event, and the adjustment direction, abnormal opening range, differential pressure disturbance, and flow recovery corresponding to the candidate debris jamming event are saved; when a subsequent opening adjustment process under the same adjustment direction occurs, the adjustment direction and abnormal opening range in the review event are read, and the repetitive hysteresis is calculated again.

[0016] In one possible implementation, after outputting the diagnostic results for momentary obstruction caused by debris or the diagnostic results for aging of the actuator, the method further includes: writing the diagnostic results, adjustment direction, abnormal opening range, response hysteresis, differential pressure disturbance, flow recovery, and repetitive hysteresis into the valve diagnostic record; when outputting the diagnostic results for momentary obstruction caused by debris, generating a flushing observation prompt and suppressing the actuator fault alarm; when outputting the diagnostic results for aging of the actuator, generating an actuator maintenance prompt and using the abnormal opening range as maintenance location information.

[0017] Secondly, this application provides a sewage valve opening fluctuation diagnostic system, comprising: The data acquisition module is used to acquire the opening command sequence, actual opening feedback sequence, valve front and valve back pressure difference sequence, and valve flow sequence of the sewage valve during a single opening adjustment process, and to determine the adjustment direction of the sewage valve based on the opening command sequence. The opening anomaly identification module is used to identify pause segments, jump segments, and response hysteresis in the actual opening feedback sequence based on the following difference between the actual opening feedback sequence and the opening command sequence. The synchronous disturbance determination module is used to time-align the pause segment, the jump segment, and the response hysteresis with the valve pre-valve and post-valve pressure difference sequence and the valve flow sequence to obtain the synchronously occurring pressure difference disturbance and flow recovery. The candidate event marking module is used to mark the current opening adjustment process as a candidate debris jamming event when the pressure difference disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition. The repetitive hysteresis calculation module is used to extract subsequent opening adjustment processes under the same adjustment direction after the candidate debris jamming event, and to calculate the repetitive hysteresis amount of the subsequent opening adjustment process. The diagnostic output module is used to output the instantaneous obstruction diagnosis result of debris when the repetitive hysteresis is less than the preset repetition threshold, and to output the aging diagnosis result of the actuator when the repetitive hysteresis is not less than the preset repetition threshold.

[0018] Compared with related technologies, this application has at least the following beneficial effects.

[0019] By acquiring the opening command sequence, actual opening feedback sequence, valve inlet and outlet pressure difference sequence, and flow rate sequence of a sewage valve during a single opening adjustment process, and determining the adjustment direction of the sewage valve based on the opening command sequence, the valve opening feedback anomaly can be established on the same data basis with the sewage flow state and adjustment direction. This avoids making a single judgment on valve anomalies based solely on hysteresis, pauses, jumps, or deviations in a single actual opening feedback curve, thereby improving the data integrity of sewage valve opening fluctuation diagnosis.

[0020] By identifying pause segments, transition segments, and response hysteresis based on the following difference between the actual opening feedback sequence and the opening command sequence, and by aligning the pause segments, transition segments, and response hysteresis with the valve pre- and post-valve pressure difference sequence and the valve flow sequence, synchronous pressure difference disturbance and flow recovery are obtained. This ensures that opening-side anomalies, pressure difference disturbances, and flow recovery can form a corresponding relationship within the same time window. Furthermore, when the pressure difference disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition, the current opening adjustment process is marked as a candidate debris jamming event, thereby reducing the situation where opening hysteresis without accompanying sewage flow anomalies is directly identified as debris jamming.

[0021] By extracting subsequent opening adjustment processes in the same adjustment direction after the candidate debris jamming event and calculating the repetitive hysteresis of the subsequent opening adjustment processes, it is possible to quantify whether the candidate debris jamming event repeatedly exhibits hysteresis or jumps in subsequent operation. Furthermore, by comparing the repetitive hysteresis with a preset repetition threshold, and outputting the instantaneous debris jamming diagnosis result when the repetitive hysteresis is less than the preset repetition threshold, and outputting the actuator aging diagnosis result when the repetitive hysteresis is not less than the preset repetition threshold, the risk of misjudging short-term debris disturbances as actuator failures and the risk of mistaking continuous mechanical degradation for sewage debris interference are reduced. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments are briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram illustrating an application scenario of a sewage valve opening fluctuation diagnostic system provided in an embodiment of this application. Figure 2 A flowchart illustrating an overall method for diagnosing fluctuations in the opening of a sewage valve, as provided in this application embodiment; Figure 3 A flowchart illustrating the acquisition of opening adjustment data and time alignment is provided in an embodiment of this application. Figure 4 A flowchart for identifying pause segments, transition segments, and response hysteresis is provided for embodiments of this application; Figure 5 A flowchart for marking candidate debris jamming events provided in this application embodiment; Figure 6 A flowchart for calculating repetitive hysteresis and outputting diagnostic results is provided in this application embodiment; Figure 7 A schematic diagram of the module structure of a sewage valve opening fluctuation diagnosis system provided in this application embodiment; Figure 8 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0024] The technical solution of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, and not all embodiments; other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0025] In this embodiment, the opening command sequence refers to a data sequence formed by arranging the target opening command values ​​output by the valve controller, PLC, DCS control system, or valve positioner according to the sampling time during a single opening adjustment process; the actual opening feedback sequence refers to a data sequence formed by arranging the actual valve position opening values ​​collected by the valve positioner, electric actuator encoder, valve position sensor, or stroke feedback device according to the sampling time; the valve pre- and post-valve pressure difference sequence refers to a data sequence formed by arranging the pressure difference between the pre-valve pressure transmitter and the post-valve pressure transmitter according to the sampling time, or a data sequence formed by arranging the differential pressure values ​​directly output by the differential pressure transmitter according to the sampling time; and the valve flow sequence refers to a data sequence formed by arranging the flow measurement values ​​provided by the flow meter installed in the pipe section where the valve is located or by the sewage treatment control system according to the sampling time.

[0026] In this embodiment, an opening adjustment process can be triggered by a change in the opening command sequence. Specifically, when the change in the opening command value relative to the previous stable opening value is not less than a preset adjustment start threshold, this moment is recorded as the adjustment start moment. When the actual opening feedback value enters the target opening allowable deviation range and remains stable for a preset stable duration, or reaches a preset maximum observation duration, the corresponding moment is recorded as the adjustment end moment. The sampled data between the adjustment start moment and the adjustment end moment constitute the data for one opening adjustment process.

[0027] In this embodiment, the pause segment refers to the sampling interval in which the change in the actual opening feedback value is less than the preset pause change threshold within a continuous period of time when the opening command is continuously changing or the target opening has not yet been reached; the jump segment refers to the sudden change interval in the actual opening feedback value between adjacent sampling times that is not less than the preset jump threshold; the response hysteresis refers to the following deviation of the actual opening feedback value relative to the opening command value, which can be represented by the maximum value, average value or cumulative deviation within a preset time window in the following difference sequence.

[0028] In this embodiment, a preset clamping disturbance condition is used to determine whether an abnormal opening is accompanied by a pressure differential characteristic of short-term obstruction of the valve's flow passage. A preset flushing recovery condition is used to determine whether the flow rate over the valve recovers after an abnormal opening. A preset repetition threshold is used to determine whether a hysteresis characteristic sufficient to characterize mechanical degradation reappears under the same adjustment direction. The above preset conditions or thresholds can be determined based on historical opening adjustment data of the same type of sewage valve under normal operating conditions, instrument resolution, process allowable deviation, and historical fault samples confirmed by maintenance. In use, the system compares the currently calculated pressure differential disturbance, flow recovery, or repetition hysteresis with the corresponding preset conditions or thresholds and outputs the corresponding judgment results.

[0029] Figure 1This application provides a schematic diagram of an application scenario for a sewage valve opening fluctuation diagnostic system. Figure 1 As shown, sewage valves are installed on the sewage pipeline. These valves can be electric regulating valves, pneumatic regulating valves, gate valves, butterfly valves, ball valves, or other valves with opening adjustment and feedback capabilities. The valve controller can receive opening commands from the sewage treatment control system and return actual opening feedback to the sewage treatment control system or diagnostic system. Pressure transmitters are installed before and after the valve, or differential pressure transmitters are installed at both ends of the valve, to collect the pressure difference before and after the valve. A flow meter is installed in the pipe section where the valve is located to collect the flow rate through the valve. After reading the above data, the diagnostic system executes the sewage valve opening fluctuation diagnostic method provided in this embodiment.

[0030] Figure 2 A flowchart illustrating a method for diagnosing fluctuations in the opening of a sewage valve, as provided in this application embodiment; see reference. Figure 2 The method may include the following steps.

[0031] See Figure 3 As shown, S101: Obtain the opening command sequence, actual opening feedback sequence, valve front and rear pressure difference sequence, and valve flow sequence of the sewage valve during a single opening adjustment process, and determine the adjustment direction of the sewage valve.

[0032] In one implementation, the diagnostic system reads the opening command value from the valve controller or DCS control system, the actual opening feedback value from the valve positioner or actuator feedback channel, the differential pressure difference before and after the valve from the differential pressure transmitter, and the flow rate through the valve from the flow meter; each data value carries the sampling time. If the sampling periods of different acquisition devices are different, the diagnostic system selects a unified sampling period and converts each sequence into a data sequence under the same sampling time by interpolation of adjacent sampling times, taking the value of the most recent time, or averaging the values. The unified sampling period can be determined according to the DCS sampling period, the valve positioner feedback period, the response time of the differential pressure transmitter, and the response time of the flow meter, and the unified sampling period is made less than a preset pause duration threshold.

[0033] In some implementations, if the differential pressure sequence before and after the valve is directly output by a differential pressure transmitter, the system reads the differential pressure value output by the transmitter at each sampling time as the differential pressure value before and after the valve. If a pressure transmitter is installed before and after the valve at both ends, the system first pairs the pressure values ​​before and after the valve according to the sampling time, and then subtracts the pressure value after the valve from the pressure value before the valve at the same sampling time to obtain the differential pressure value before and after the valve at that sampling time. If a pressure value before or after the valve is missing at a certain sampling time, the differential pressure value at that sampling time is not included in the calculation of differential pressure disturbance and is recorded as a missing sampling point.

[0034] In some implementations, when there is a discrepancy in the local time of different acquisition devices, the diagnostic system uses the time of the wastewater treatment control system server or the time of the edge computing device as a unified time reference. When the system receives each acquisition value, it adds the reception time under the unified time reference to each acquisition value and combines it with the original sampling time reported by the acquisition device to form a corrected sampling time.

[0035] In some implementations, the system separately counts the total number of sampling points and the number of missing sampling points during the regulation process. The number of missing sampling points includes the number of sampling points where the upstream and downstream pressure values ​​cannot be matched, the number of sampling points lacking flow values, and the number of sampling points lacking actual opening feedback values. A valid sampling point refers to a sampling point whose sampling time falls within the corresponding time window, whose sampling value is not missing, whose acquisition device status is marked as normal, whose sampling value is within the range of the corresponding instrument, and which is not marked as communication interruption data. Specifically, for the upstream and downstream pressure difference sequence, if the pressure difference value is directly output by the differential pressure transmitter, then when the differential pressure transmitter has a valid differential pressure value at the corresponding sampling time, that sampling time is counted as a valid differential pressure sampling point. If the pressure difference value is calculated from the upstream and downstream pressure values, then when both the upstream and downstream pressure values ​​at the same sampling time meet the above valid sampling point conditions, that sampling time is counted as a valid differential pressure sampling point. For the flow rate sequence, when the flow meter has a valid flow value at the corresponding sampling time, that sampling time is counted as a valid flow rate sampling point. The system counts the number of sampling points that meet the above conditions in the baseline window, the anomaly window, and the recovery window, respectively, to obtain the number of effective differential pressure sampling points in the baseline window, the number of effective differential pressure sampling points in the anomaly window, and the number of effective flow rate sampling points in the recovery window. If the ratio of the number of missing sampling points in the same adjustment process to the total number of sampling points in that adjustment process is not less than the preset missing ratio, the system records this opening adjustment process as a data insufficiency process and does not output the instantaneous obstruction diagnosis result or the actuator aging diagnosis result. The preset missing ratio is determined based on the minimum number of effective sampling points required by the differential pressure disturbance and the flow rate recovery. When any one of the following is lower than the corresponding minimum number of effective sampling points: the number of effective differential pressure sampling points in the baseline window, the number of effective differential pressure sampling points in the anomaly window, or the number of effective flow rate sampling points in the recovery window, the system does not execute the candidate obstruction event marking.

[0036] In one implementation, the system reads the initial command opening and the target command opening from the opening command sequence. If the target command opening is greater than the initial command opening, the adjustment direction is determined to be the opening direction; if the target command opening is less than the initial command opening, the adjustment direction is determined to be the closing direction. The system generates an opening adjustment data packet for this opening adjustment process. This opening adjustment data packet includes the valve number, adjustment start time, adjustment end time, adjustment direction, opening command sequence, actual opening feedback sequence, valve inlet and outlet pressure difference sequence, and valve flow sequence. This opening adjustment data packet is used for subsequent calculations of pause segments, jump segments, response hysteresis, and pressure difference and flow disturbances.

[0037] For example, at 10:00:00, the inlet regulating valve of a sewage pumping station receives a control command to adjust the opening degree from 30% to 40%. The system reads the opening command value, actual opening degree feedback value, valve front and rear pressure difference value, and valve flow value between 10:00:00 and 10:00:30, and marks the adjustment direction as the opening direction.

[0038] See Figure 4 As shown, S102: Based on the following difference between the actual opening feedback sequence and the opening command sequence, identify the pause segment, jump segment and response hysteresis in the actual opening feedback sequence.

[0039] In one implementation, the diagnostic system calculates the absolute value of the difference between the actual opening feedback value and the opening command value point by point according to the sampling time, obtaining a follow-up difference sequence. The system further calculates the change in the actual opening feedback value between adjacent sampling times, obtaining a feedback change sequence. If the feedback change is continuously less than a preset pause change threshold, and the duration of this continuous interval is not less than a preset pause duration threshold, then the continuous interval is marked as a pause segment. The preset pause change threshold can be determined based on the resolution of the opening feedback sensor and the minimum effective change between adjacent sampling times during normal adjustment, for example, taking the larger value between twice the resolution of the opening feedback sensor and the historical minimum effective change. The preset pause duration threshold can be determined based on the normal response time of the valve and the control cycle, for example, taking a multiple of the control cycle, so that a single sampling noise will not be identified as a pause segment.

[0040] In one implementation, if the change in the actual opening feedback value between two adjacent sampling times is not less than a preset jump threshold, then the adjacent sampling interval is marked as a jump segment. The preset jump threshold can be determined based on the maximum single-cycle opening change during normal adjustment, the rated operating speed of the actuator, and the resolution of the opening feedback sensor. The system can also use the maximum value in the following difference sequence as the response hysteresis, or use the average value of the following difference within a preset time window near the pause segment or jump segment as the response hysteresis. When the response hysteresis is represented by the maximum value in the following difference sequence, the system simultaneously records the sampling time corresponding to the maximum following difference; when the response hysteresis is represented by the average value within a preset time window, the system simultaneously records the preset time window as the response hysteresis window.

[0041] In some implementations, pause segment identification can also be combined with the operating status of the valve actuator for filtering. The system reads the operating power status of the actuator, the air supply pressure value of the pneumatic valve, and the execution status of the valve controller. When the operating power of the actuator is interrupted, the air supply pressure value of the pneumatic valve is lower than the preset lower limit of the air supply pressure, or the valve controller returns to the stop execution state, the system does not identify the actual opening feedback pause during that time period as a pause segment, but records that time period as a control-side interruption period. The preset lower limit of the air supply pressure is determined based on the lower limit of the rated working pressure on the nameplate of the pneumatic actuator, the lower limit of the allowable air supply pressure of the positioner, and the lowest air supply pressure value during historical normal operation. At each sampling moment, the system compares the air supply pressure value with the preset lower limit of the air supply pressure and uses the comparison result for pause segment filtering.

[0042] Through the above processing, the system generates anomaly identification results. These results include the start and end sampling times of the pause segment, the actual opening range corresponding to the pause segment, the start and end sampling times of the jump segment, the actual opening feedback values ​​before and after the jump, the response hysteresis, the sampling time or response hysteresis window corresponding to the response hysteresis, and the adjustment direction. These anomaly identification results are used for subsequent time alignment with the pre- and post-valve pressure difference sequences and the flow rate sequence.

[0043] See Figure 5 As shown, S103: The pause segment, jump segment and response hysteresis are time-aligned with the differential pressure sequence before and after the valve and the flow sequence through the valve to obtain the synchronously occurring differential pressure disturbance and flow recovery.

[0044] In one implementation, the diagnostic system constructs an anomaly window based on the start and end sampling times of the pause and transition segments. If both a pause and a transition segment exist simultaneously during the same opening adjustment process, and the time interval between them is less than a preset anomaly merging time, then the time range from the start time of the pause segment to the end time of the transition segment is used as the anomaly window. If only a pause segment exists, then the start and end sampling times of the pause segment are used as the anomaly window; if only a transition segment exists, then the start and end sampling times of the transition segment are used as the anomaly window. When the response hysteresis is represented by the maximum value in the following difference sequence, the system incorporates the sampling time corresponding to the maximum following difference into the anomaly window; when the response hysteresis is represented by the average value within a preset time window, the system uses this preset time window as the response hysteresis window and uses the response hysteresis window together with the pause and transition segments for differential pressure-flow time alignment.

[0045] The preset anomaly merging duration can be determined based on the feedback sampling period, actuator mechanical release time, and opening feedback signal transmission delay of the sewage valve during normal opening adjustment. For example, the system reads the time interval between the end of the pause segment and the start of the adjacent jump segment from historical normal adjustment data. After removing abnormal intervals caused by control pauses, insufficient gas supply, or communication interruptions, the upper limit or preset percentile value of the remaining time interval is taken, and corrected by combining it with an integer multiple of the sampling period to obtain the preset anomaly merging duration. During the current opening adjustment process, if the time interval between the end of the pause segment and the start of the jump segment is not greater than the preset anomaly merging duration, the system merges the pause segment and the jump segment into the same anomaly window; if it is greater than the preset anomaly merging duration, they are treated as different anomaly windows.

[0046] The system selects a sampling interval of a preset reference duration as the reference window before the abnormal window, reads the differential pressure values ​​before and after the valve within the reference window, and calculates the reference differential pressure value. The reference differential pressure value can be the average or median value of the differential pressure values ​​within the reference window. The system further reads the differential pressure values ​​before and after the valve within the abnormal window, calculates the maximum absolute deviation of the differential pressure value within the abnormal window from the reference differential pressure value, and uses this maximum absolute deviation as the differential pressure disturbance.

[0047] The system reads the valve flow rate within the abnormal window and determines the lowest flow rate or the maximum flow rate deviation relative to the expected flow rate at the target opening. After the abnormal window, the system selects a sampling interval with a preset recovery time as the recovery window and reads the valve flow rate within it. The system can use the difference between the average flow rate within the recovery window and the lowest flow rate within the abnormal window as the flow rate recovery amount, or it can use the recovery range of the average flow rate within the recovery window back to the preset allowable flow rate range corresponding to the target opening as the flow rate recovery amount.

[0048] The preset recovery time can be determined based on the hydraulic lag time of the pipe section where the valve is located, the flow meter response time, the control system sampling period, and the historical flow stabilization time near the target opening. For example, the system reads the time required for the flow rate to enter the preset allowable flow range corresponding to the target opening after the actual opening reaches the target opening from the historical normal opening adjustment data. The preset quantile of this time is taken and compared with an integer multiple of the flow meter response time and the sampling period; the larger of these is used as the preset recovery time. The preset recovery time should not be less than the time required for the flow meter to complete one effective response, nor should it be greater than the time interval between adjacent process adjustment actions that may cause flow changes. During the current opening adjustment process, the system takes the end time of the abnormal window as the starting point, extracts the sampling interval within the preset recovery time as the recovery window, and calculates the flow recovery amount within this recovery window.

[0049] In some implementations, before calculating the differential pressure disturbance and flow recovery, the system first reads the pump start / stop status, upstream liquid level change, and adjacent valve opening change. When a pump start / stop event, an upstream liquid level change not less than a preset liquid level fluctuation threshold, or an adjacent valve opening change not less than a preset adjacent valve disturbance threshold exists within the anomaly window, the system marks the corresponding differential pressure disturbance and flow change as external hydraulic disturbances. The preset liquid level fluctuation threshold can be determined based on the resolution of the upstream liquid level gauge in the pipe section where the valve is located and the upper limit of liquid level fluctuation per unit time during historical stable operation. The preset adjacent valve disturbance threshold can be determined based on the upper limit of historical disturbances caused by the normal adjustment of adjacent valves to the differential pressure and flow in the pipe section where the valve is located. Within the anomaly window, the system calculates the upstream liquid level change and the adjacent valve opening change respectively, and compares them with the preset liquid level fluctuation threshold and the preset adjacent valve disturbance threshold respectively. When any comparison result meets the external hydraulic disturbance judgment condition, an external hydraulic disturbance mark is generated.

[0050] For opening adjustment processes marked as external hydraulic disturbances, the system does not mark them as candidate debris jamming events, and writes the external hydraulic disturbance mark, pump start / stop status, upstream liquid level change, and adjacent valve opening change into the diagnostic record. This diagnostic record is used to indicate that the differential pressure disturbance and flow recovery were not involved in the diagnosis of instantaneous debris jamming.

[0051] Through the above processing, the system generates synchronization disturbance results. These results include the abnormal window, baseline differential pressure value, differential pressure disturbance amount, peak time of differential pressure disturbance, abnormal window flow rate, recovery window flow rate, flow recovery amount, flow recovery time, and external hydraulic disturbance markers. These synchronization disturbance results are used for subsequent markers of candidate debris jamming events.

[0052] Continue reading Figure 5As shown, S104: When the differential pressure disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition, the current opening adjustment process is marked as a candidate debris jamming event.

[0053] In one implementation, the preset clamping disturbance condition includes a differential pressure disturbance amplitude condition and a differential pressure disturbance timing condition. The differential pressure disturbance amplitude condition is that the differential pressure disturbance amount is not less than a preset differential pressure disturbance threshold. The preset differential pressure disturbance threshold can be determined as follows: select the differential pressure fluctuation value corresponding to the historical normal adjustment process of the same valve or valve of the same model without debris jamming or actuator failure, and take the preset quantile value of the differential pressure fluctuation value as the upper limit of historical differential pressure fluctuation; at the same time, read the resolution of the differential pressure transmitter, and take the preset multiple of the resolution of the differential pressure transmitter as the minimum effective disturbance value of the instrument; take the larger of the historical differential pressure fluctuation upper limit and the minimum effective disturbance value of the instrument as the preset differential pressure disturbance threshold. The differential pressure disturbance timing condition is that the peak time of the differential pressure disturbance is located in the pause segment, the jump segment, or a preset extended time window adjacent to the pause segment or the jump segment.

[0054] The preset extended time window can be determined based on the differential pressure transmitter response time, data acquisition synchronization error, control system sampling period, and short-term hydraulic transmission lag of the pipe section where the valve is located. For example, the system reads historical normal regulation data and confirmed obstruction samples, and calculates the time offset between the occurrence time of the opening pause or jump segment and the peak time of the differential pressure disturbance. After eliminating abnormal offsets caused by pump start-up / stop, adjacent valve actions, and communication interruptions, the upper limit or preset quantile value of the remaining time offset is taken, and corrected by combining it with an integer multiple of the sampling period to obtain the preset extended time window. During the current opening regulation process, if the peak time of the differential pressure disturbance is located within the pause segment, jump segment, or the preset extended time window before or after it, the differential pressure disturbance and the opening abnormality are determined to correspond in time. If it exceeds this time window, the differential pressure disturbance timing condition is not met.

[0055] In one embodiment, the preset flushing recovery conditions include a flow recovery amplitude condition and a recovery time condition. The flow recovery amplitude condition requires that the flow recovery amount is not less than a preset flow recovery threshold. The preset flow recovery threshold can be determined based on the flow fluctuation range of the same valve during historical stable operation near the target opening, for example, taking the larger value between the upper limit of historical stable flow fluctuation and a preset multiple of the flowmeter resolution. The recovery time condition requires that the flow value through the valve returns to the preset allowable flow range corresponding to the target opening within a preset recovery time after the end of the abnormal window. The preset allowable flow range can be determined based on the valve flow characteristic curve, the target opening, the pressure difference before and after the valve, and the process allowable flow deviation. It is not fixed to a single flow value and can be set by those skilled in the art according to actual needs, and is not specifically limited here.

[0056] When the differential pressure disturbance simultaneously meets the differential pressure disturbance amplitude condition and the differential pressure disturbance timing condition, and the flow recovery simultaneously meets the flow recovery amplitude condition and the recovery time condition, the system marks this opening adjustment process as a candidate debris jamming event. The candidate debris jamming event includes the valve number, event time, adjustment direction, abnormal opening range, pause section, jump section, response hysteresis, differential pressure disturbance, flow recovery, and target opening. This candidate debris jamming event is used for the calculation of repeated hysteresis under the same adjustment direction in the future.

[0057] When the differential pressure disturbance does not meet the preset clamping disturbance condition, or the flow recovery does not meet the preset flushing recovery condition, the system does not generate a candidate debris jamming event. Instead, it writes the valve number, adjustment direction, abnormal opening interval, pause segment, jump segment, and response hysteresis of the current opening adjustment process into the opening anomaly record. When calculating the repeated hysteresis in the subsequent calculation, the system reads the adjustment direction and abnormal opening interval from the opening anomaly record to filter subsequent opening adjustment processes with the same adjustment direction and similar opening intervals.

[0058] For example, when the return sludge regulating valve of a wastewater treatment plant is opened from 25% to 35%, the actual opening feedback pauses for 2.5 seconds around 29%, then jumps to 34.6%. During this pause and its adjacent extended time window, the system detects that the pressure difference between the valve and its inlet / outlet increases from 18 kPa to 31 kPa, with a pressure difference disturbance of 13 kPa. Furthermore, within 8 seconds after the abnormal window ends, the flow rate through the valve recovers from 420 m³ / h to the allowable range of 500 m³ / h to 530 m³ / h corresponding to the target opening. In this case, the opening pause, the short-term increase in pressure difference, and the flow rate recovery are time-dependent, and the system marks this opening adjustment process as a candidate debris jamming event. If a similar pause occurs around 29%, but the pressure difference does not exceed the preset pressure difference disturbance threshold for a short period, or the flow rate does not recover to the preset allowable flow rate range corresponding to the target opening after the abnormality, the system does not mark it as a candidate debris jamming event, but instead retains it as an opening abnormality record or mechanical hysteresis warning.

[0059] In some implementations, if the differential pressure disturbance meets the preset clamping disturbance condition, but the flow recovery does not meet the preset flushing recovery condition, the system does not output a diagnostic result for instantaneous obstruction caused by debris, but instead generates an unrecovered obstruction warning. The unrecovered obstruction warning includes the valve number, adjustment direction, abnormal opening range, differential pressure disturbance, and the unmet flushing recovery condition. If the differential pressure disturbance does not meet the preset clamping disturbance condition, but the response hysteresis is not less than a preset hysteresis threshold, the system generates a mechanical hysteresis warning. The mechanical hysteresis warning includes the valve number, adjustment direction, abnormal opening range, and response hysteresis, and is used for subsequent calculations of repeated hysteresis under the same adjustment direction. The preset hysteresis threshold is determined based on the upper limit of the response hysteresis during the historical normal opening adjustment process of the same valve and the resolution of the opening feedback sensor.

[0060] See Figure 6 As shown, S105: After the candidate debris jamming event, extract the subsequent opening adjustment process under the same adjustment direction, and calculate the repetitive hysteresis of the subsequent opening adjustment process.

[0061] In one implementation, the system reads the adjustment direction and abnormal opening range in the candidate debris jamming event. The abnormal opening range can be determined by the minimum and maximum values ​​of the actual opening feedback value within the pause and jump segments; for example, if the actual opening feedback value pauses around 34% and then jumps from 34% to 39%, the abnormal opening range can be recorded as 34% to 39%, or it can be recorded as the pause center opening of 34% and its preset tolerance range.

[0062] Within a preset review period following a candidate obstruction event, the system filters subsequent opening adjustment processes for the same valve and in the same adjustment direction from the historical opening adjustment database. For each subsequent opening adjustment process, the system reads the actual opening feedback sequence and extracts the sampling interval that falls within the abnormal opening range and its preset opening tolerance range. The preset opening tolerance range can be determined based on the resolution of the opening feedback sensor and the normal adjustment fluctuations of the valve, for example, by taking a multiple of the resolution of the opening feedback sensor.

[0063] Within the captured sampling interval, the system repeatedly performs pause recognition, jump recognition, and follow-up difference calculation to obtain the duration of subsequent pauses, the amplitude of subsequent jumps, and the follow-up difference. The system can use the maximum value of the follow-up difference as the repetition hysteresis, or it can convert the duration of subsequent pauses into an opening hysteresis according to a preset hysteresis conversion rule, and then perform a weighted sum with the follow-up difference to obtain the repetition hysteresis.

[0064] The preset hysteresis conversion rule can be determined based on the rated opening change rate of the sewage valve, the sampling period of the control system, the resolution of the opening feedback sensor, and historical opening adjustment data. Specifically, the system first reads the rated opening change rate from the valve nameplate parameters or actuator parameters, multiplies the subsequent pause duration by the rated opening change rate, and obtains the equivalent opening hysteresis. If there is a deviation between the actual opening change rate and the rated opening change rate in the historical normal adjustment data, the system can determine the historical opening change rate based on the ratio of the actual opening change to the corresponding adjustment duration during the historical normal adjustment process, and use the smaller of the rated opening change rate and the historical opening change rate as the hysteresis conversion rate. The equivalent opening hysteresis and the subsequent follow-up difference are both expressed as an opening percentage or opening unit to ensure that they are on the same dimension. If the repetitive hysteresis is obtained by weighted summation of the subsequent follow-up difference and the equivalent opening hysteresis, then the weights of the subsequent follow-up difference and the equivalent opening hysteresis are determined based on the distinguishing power of two indicators in the confirmed normal adjustment samples and the confirmed actuator aging samples, and the sum of their weights is 1. When calculating the repetitive hysteresis, the system reads the duration of the subsequent pause and the subsequent follow-up difference, obtains the equivalent opening hysteresis according to the preset hysteresis conversion rule, and then weights and sums the subsequent follow-up difference and the equivalent opening hysteresis to obtain the repetitive hysteresis used for comparison with the preset repetition threshold.

[0065] In some implementations, the repetitive hysteresis can be determined by the maximum following difference, the equivalent opening hysteresis, and the number of repetitions during subsequent adjustment. The system first multiplies the duration of the pause by the valve's rated opening change rate to obtain the equivalent opening hysteresis; then, it multiplies the maximum following difference, the equivalent opening hysteresis, and the number of repetitions by their respective weights and sums them to obtain the repetitive hysteresis. Each weight can be determined based on the discriminative power of the three indicators in confirmed debris jamming samples and actuator aging samples, and should remain consistent within the same valve type.

[0066] If there are multiple subsequent opening adjustment processes, the system can calculate the hysteresis of each subsequent opening adjustment process separately and take the maximum value as the repetitive hysteresis; alternatively, it can take the average of the hysteresis of multiple subsequent opening adjustment processes as the repetitive hysteresis. The calculation method for the repetitive hysteresis is consistent across the same valve or valves of the same type, and uses the same dimensions as the preset repetition threshold.

[0067] In one implementation, if no subsequent opening adjustment process in the same adjustment direction is extracted within a preset review period, the system marks the candidate debris jamming event as a review event. The review event includes the valve number, adjustment direction, abnormal opening range, differential pressure disturbance, flow recovery, and event time. When a subsequent opening adjustment process in the same adjustment direction occurs, the system reads the review event and continues to calculate the repetitive hysteresis. The retention period for the review event can be determined based on the historical average adjustment interval of the wastewater valve. If no subsequent opening adjustment process in the same adjustment direction occurs by the end of the retention period, the system can output a data insufficiency warning instead of directly identifying the review event as momentary debris jamming or actuator aging.

[0068] Continue reading Figure 6 As shown, S106: Based on the comparison result between the repetitive hysteresis amount and the preset repetitive threshold, output the instantaneous jamming diagnosis result of debris or the aging diagnosis result of the actuator.

[0069] In one implementation, the preset repetition threshold can be determined based on the historical repetitive hysteresis of the same valve under normal adjustment conditions, the resolution of the opening sensor, and maintenance records. For example, the system can read the repetitive hysteresis within the same opening range during historical normal adjustment, take its preset quantile value as the upper limit of normal repetitive hysteresis, and use the larger value between the upper limit of normal repetitive hysteresis and a preset multiple of the opening sensor resolution as the preset repetition threshold. If there are historical samples with confirmed actuator aging, the boundary value between the upper limit of normal samples and the lower limit of aging samples can also be used as the preset repetition threshold.

[0070] When the repetitive hysteresis is less than the preset repetition threshold, it indicates that no similar opening interval hysteresis or jump has occurred repeatedly in the same adjustment direction, and the system outputs a diagnostic result for instantaneous obstruction due to debris. This diagnostic result may include valve number, event time, abnormal opening interval, candidate obstruction event number, differential pressure disturbance, flow recovery, repetitive hysteresis, and diagnostic type. Based on this, the system can generate flushing observation prompts and suppress actuator fault alarms.

[0071] When the repetitive hysteresis is not less than the preset repetition threshold, it indicates that hysteresis or jumps still exist in the same opening range under the same adjustment direction, and the system outputs the actuator aging diagnosis result. This actuator aging diagnosis result is used to indicate continuous degradation conditions such as decreased actuator output capacity, increased internal transmission clearance of the actuator, or reduced actuator drive response capability. For repetitive hysteresis caused by valve stem jamming or increased packing friction, the system can add a mechanical blockage prompt to the diagnostic record, but without changing the output name of the actuator aging diagnosis result. This diagnostic result can include valve number, abnormal opening range, number of subsequent repetitions, repetitive hysteresis, response hysteresis, differential pressure disturbance, and diagnosis type. The system can generate actuator maintenance prompts based on this and use the abnormal opening range as maintenance location information.

[0072] For example, when the inlet regulating valve is adjusted from 30% to 40% opening, the actual opening feedback pauses for 3 seconds around 34% before jumping to 39%. Simultaneously, the pressure difference between the valve and its inlet / outlet peaks during this pause, and the flow rate recovers to the target opening's allowable flow range within 10 seconds after the pause. The system marks this process as a candidate obstruction event. Subsequently, when the valve is adjusted from 30% to 40% opening again, the actual opening feedback smoothly passes through the 34% to 39% range, and the repetition hysteresis is less than the preset repetition threshold. The system then outputs a diagnostic result for instantaneous obstruction. If the valve pauses in the 34% to 39% range in multiple subsequent adjustments in the same direction, and the repetition hysteresis is not less than the preset repetition threshold, the system outputs a diagnostic result for actuator aging.

[0073] For example, when the sludge discharge regulating valve is closed from 60% to 45%, the actual opening pauses around 52%, and the pressure difference between the valve and its upstream and downstream valves increases briefly during this pause. Subsequently, the actual opening suddenly drops to 46%, and the flow rate returns to the allowable range corresponding to the 45% opening within the preset recovery time after the pause. If the sludge discharge regulating valve can smoothly pass through the 52% opening range when subsequently closed from around 60% to around 45%, the system outputs a diagnosis result for momentary obstruction due to debris. If subsequent pausing or abrupt changes occur around 52% during multiple closure processes, the system outputs a diagnosis result for actuator aging.

[0074] In some implementations, after the system outputs the diagnostic result for momentary obstruction caused by debris, it does not immediately clear the candidate obstruction event but retains it until the end of a preset observation period. If the same valve experiences another candidate obstruction event within the same abnormal opening range during the observation period, the system updates the diagnostic result to a frequent obstruction warning and outputs prompts for pipe cleaning, bar screen interception, or valve front-end filter inspection. The preset observation period can be determined based on the historical average adjustment interval of the same valve and the historical recurrence interval of sewage obstruction events.

[0075] Figure 7 This is a schematic diagram of the module structure of a sewage valve opening fluctuation diagnosis system provided in an embodiment of this application. The system includes a data acquisition module, an opening anomaly identification module, a synchronization disturbance determination module, a candidate event marking module, a repetitive hysteresis calculation module, and a diagnostic output module.

[0076] The data acquisition module reads data with sampling times from the valve controller, valve positioner, differential pressure transmitter, and flow meter, and generates an opening adjustment data package. The opening anomaly identification module reads the opening command sequence and actual opening feedback sequence from the opening adjustment data package, calculates the following difference sequence, and generates pause segments, jump segments, and response hysteresis. The synchronization disturbance determination module reads the opening anomaly identification results, the valve inlet and outlet differential pressure sequences, and the through-valve flow sequence, generating differential pressure disturbance and flow recovery quantities. The candidate event marking module compares the differential pressure disturbance with preset clamping disturbance conditions and the flow recovery with preset flushing recovery conditions, generating a candidate debris jamming event when both are satisfied. The repetitive hysteresis calculation module reads the candidate debris jamming event and the subsequent opening adjustment process in the same adjustment direction, calculating the repetitive hysteresis. The diagnostic output module compares the repetitive hysteresis with a preset repetitive threshold and outputs the instantaneous debris jamming diagnostic result or the actuator aging diagnostic result.

[0077] In one implementation, the system can be deployed on a supervisory control server in a wastewater treatment plant, an edge computing device in a local control cabinet of a pumping station, or as a functional module in a DCS system, PLC system, or equipment management platform. Each module can be implemented through software programs, hardware circuits, programmable logic devices, or a combination of hardware and software.

[0078] Figure 8 This is a schematic diagram of a computer device provided in an embodiment of this application. The computer device may include a processor, a memory, a communication interface, and a bus. The memory is used to store computer programs and valve diagnostic records; the communication interface is used to communicate with valve controllers, differential pressure transmitters, flow meters, DCS systems, or upper-level monitoring platforms; the processor is used to execute the computer program in the memory to implement the sewage valve opening fluctuation diagnostic method provided in this embodiment of the application.

[0079] This application also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program enables a computer device to perform the aforementioned sewage valve opening fluctuation diagnosis method. The computer-readable storage medium may include a read-only memory, random access memory, magnetic disk, optical disk, flash memory, or other media capable of storing program code.

[0080] It should be noted that the "preset" mentioned in the above embodiments does not mean arbitrary setting, but rather refers to a callable value, range, or judgment condition formed based on normal adjustment data of similar valves, instrument resolution, valve rated response performance, and confirmed maintenance records before the diagnostic system is put into use, or after changes in valve model, instrument range, or sewage operating conditions. During the diagnostic process, the system uses the currently calculated differential pressure disturbance, flow recovery, and repetitive hysteresis as inputs, compares them with the corresponding preset thresholds or preset conditions, and outputs candidate event marking results or final diagnostic results based on the comparison results.

[0081] Furthermore, the preset adjustment start threshold can be determined based on the valve's minimum effective adjustment step size and the resolution of the opening feedback sensor; the allowable deviation range of the target opening can be determined based on the allowable flow control deviation of the wastewater treatment process and the control accuracy of the valve positioner; the preset stabilization duration can be an integer multiple of the control system's sampling period and greater than the short-term jitter duration of the valve feedback signal; the preset maximum observation duration can be determined based on the valve's maximum stroke time, the actuator's rated speed, and the safety alarm time limit; the preset abnormal merging duration can be determined based on the normal mechanical release time between the end of the pause section and the beginning of the jump section; the preset reference duration and preset recovery duration can be determined based on the hydraulic lag time of the pipe section where the valve is located, the flow meter response time, and the differential pressure transmitter response time; the preset verification cycle can be determined based on the average adjustment interval of the wastewater valve in historical operation. When the system calls the above preset items, it compares the currently collected or calculated opening change, stabilization duration, differential pressure disturbance, flow recovery, or repetitive hysteresis with the corresponding preset items, and outputs the adjustment process division result, abnormal identification result, candidate event marking result, or final diagnosis result.

[0082] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the technical solutions of this application. The above examples are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are merely preferred embodiments of this application. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes, or combinations, or the direct application of the concept and technical solutions of this application to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for diagnosing fluctuations in the opening degree of a sewage valve, characterized in that, include: The system acquires the opening command sequence, actual opening feedback sequence, valve inlet and outlet pressure difference sequence, and flow rate sequence of the sewage valve during a single opening adjustment process, and determines the adjustment direction of the sewage valve based on the opening command sequence. Based on the following difference between the actual opening feedback sequence and the opening command sequence, the pause segment, jump segment and response hysteresis in the actual opening feedback sequence are identified; The pause segment, the jump segment, and the response hysteresis are time-aligned with the valve pre-valve and post-valve differential pressure sequence and the valve flow sequence to obtain the synchronously occurring differential pressure disturbance and flow recovery. When the differential pressure disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition, the current opening adjustment process is marked as a candidate debris jamming event. After the candidate debris jamming event, the subsequent opening adjustment process under the same adjustment direction is extracted, and the repetition hysteresis of the subsequent opening adjustment process is calculated. If the repetition hysteresis is less than the preset repetition threshold, the instantaneous obstruction diagnosis result of the debris is output. If the repetitive hysteresis is not less than the preset repetition threshold, then the aging diagnosis result of the actuator is output.

2. The method as described in claim 1, characterized in that, Determining the adjustment direction of the sewage valve according to the opening command sequence includes: The opening command value at the start time in the opening command sequence is taken as the initial command opening, and the opening command value corresponding to when the actual opening feedback value enters the target opening allowable deviation range and remains stable for a preset time is taken as the target command opening. When the target command opening degree is greater than the initial command opening degree, the adjustment direction is marked as the opening direction; When the target command opening degree is less than the initial command opening degree, the adjustment direction is marked as the closing direction, and the adjustment direction is associated with and stored in this opening degree adjustment process.

3. The method as described in claim 1, characterized in that, Based on the following difference between the actual opening feedback sequence and the opening command sequence, the pause segments, transition segments, and response hysteresis in the actual opening feedback sequence are identified, including: Calculate the absolute difference between the actual opening feedback value and the opening command value at each sampling time to obtain the following difference sequence; The sampling interval in which the continuous change of the actual opening feedback value is less than the preset pause change threshold and the duration is not less than the preset pause duration threshold is identified as a pause segment; The sampling interval in which the change in the actual opening feedback value at adjacent sampling times is not less than the preset jump threshold is identified as the jump segment; The maximum value in the following difference sequence or the mean value within a preset time window is used as the response hysteresis.

4. The method as described in claim 1, characterized in that, The synchronously occurring differential pressure disturbance and flow recovery are obtained, including: Using the start and end sampling times corresponding to the pause segment and the jump segment, and the sampling time of the maximum following difference or the response hysteresis window corresponding to the response hysteresis, as the abnormal window, a preset alignment time is extended before and after the abnormal window to obtain the differential pressure flow alignment window. Within the differential pressure and flow rate alignment window, read the differential pressure value before and after the valve and the flow rate through the valve. Take the maximum deviation of the differential pressure within the abnormal window as the differential pressure disturbance, and take the flow rate recovery amplitude after the abnormal window ends as the flow rate recovery.

5. The method as described in claim 1, characterized in that, The preset clamping disturbance conditions include differential pressure disturbance amplitude conditions and differential pressure disturbance timing conditions; The differential pressure disturbance amplitude condition is that the differential pressure disturbance amount is not less than a preset differential pressure disturbance threshold. The timing condition for the differential pressure disturbance is that the peak time of the differential pressure disturbance is located within the pause segment, the jump segment, or an adjacent extended time window of the pause segment and the jump segment.

6. The method as described in claim 1, characterized in that, The preset flushing recovery conditions include flow recovery magnitude conditions and recovery time conditions; The condition for the flow recovery magnitude is that the flow recovery amount is not less than a preset flow recovery threshold. The recovery time condition is that the overflow rate value returns to the preset flow allowable range corresponding to the target opening within a preset recovery time after the end of the pause or the jump segment.

7. The method as described in claim 1, characterized in that, The calculation of the repetitive hysteresis in the subsequent opening adjustment process includes: Read the abnormal opening interval corresponding to the candidate debris jamming event. The abnormal opening interval is determined by the minimum and maximum values ​​of the actual opening feedback values ​​within the pause segment and the jump segment. During subsequent opening adjustment processes in the same adjustment direction, sampling intervals falling within the abnormal opening interval and its preset opening tolerance range are selected; Calculate the maximum following difference and the duration of the pause within the sampling interval, and convert them into the repetition hysteresis amount according to the preset hysteresis conversion rule.

8. The method as described in claim 1, characterized in that, If, after the candidate debris jamming event, no subsequent opening adjustment process under the same adjustment direction is extracted within the preset review period, the candidate debris jamming event is marked as an event to be reviewed, and the adjustment direction, abnormal opening range, differential pressure disturbance and flow recovery amount corresponding to the candidate debris jamming event are saved. When a subsequent opening adjustment process with the same adjustment direction occurs, the adjustment direction and abnormal opening interval in the event to be reviewed are read, and the repetitive hysteresis is calculated again.

9. The method as described in claim 1, characterized in that, After outputting the diagnostic results for momentary obstruction due to foreign matter or the diagnostic results for aging of the actuator, the method further includes: Write the diagnostic results, adjustment direction, abnormal opening range, response hysteresis, differential pressure disturbance, flow recovery, and repetitive hysteresis into the valve diagnostic record; When the output shows the diagnostic result of momentary obstruction by debris, a flushing observation prompt is generated and the actuator fault alarm is suppressed. When the aging diagnosis results of the actuator are output, an actuator maintenance prompt is generated, and the abnormal opening range is used as maintenance location information.

10. A sewage valve opening fluctuation diagnostic system, characterized in that, include: The data acquisition module is used to acquire the opening command sequence, actual opening feedback sequence, valve front and valve back pressure difference sequence, and valve flow sequence of the sewage valve during a single opening adjustment process, and to determine the adjustment direction of the sewage valve based on the opening command sequence. The opening anomaly identification module is used to identify pause segments, jump segments, and response hysteresis in the actual opening feedback sequence based on the following difference between the actual opening feedback sequence and the opening command sequence. The synchronous disturbance determination module is used to time-align the pause segment, the jump segment, and the response hysteresis with the valve pre-valve and post-valve pressure difference sequence and the valve flow sequence to obtain the synchronously occurring pressure difference disturbance and flow recovery. The candidate event marking module is used to mark the current opening adjustment process as a candidate debris jamming event when the pressure difference disturbance meets the preset clamping disturbance condition and the flow recovery meets the preset flushing recovery condition. The repetitive hysteresis calculation module is used to extract subsequent opening adjustment processes under the same adjustment direction after the candidate debris jamming event, and to calculate the repetitive hysteresis amount of the subsequent opening adjustment process. The diagnostic output module is used to output the instantaneous obstruction diagnosis result of debris when the repetitive hysteresis is less than the preset repetition threshold, and to output the aging diagnosis result of the actuator when the repetitive hysteresis is not less than the preset repetition threshold.

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