A method for reducing overflow pollution of a sewer network and recycling

Abstract

The present application relates to rainwater collection and utilization technical field, disclose a kind of drainage pipe network overflow pollution reduction and resource utilization method, comprising: installing heteromorphic turbulence unit in pipe network water inlet to induce pipe wall mechanical vibration, vibration signal is collected using acoustic detection unit and extracting main vibration frequency, simultaneously using non-contact electrode to collect fluid conductivity signal, based on signal time delay calculation fluid real-time flow rate, according to real-time flow rate correction main vibration frequency obtains characteristic frequency deviation, weighted calculation characteristic frequency deviation and conductivity signal instantaneous gradient, and generate split characteristic value, extract low-frequency energy distribution in vibration signal to determine scour intensity index, according to split characteristic value and scour intensity index switch flow path, the present application is decoupled by acoustoelectric coupling to flow state and concentration, effectively capture sediment starting feature, improve overflow pollution monitoring precision and prediction ability.

Description

Technical Field

[0001] This invention belongs to the field of rainwater harvesting and utilization technology, and in particular relates to a method for reducing pollution and utilizing resources from overflow in drainage pipe networks. Background Technology

[0002] Currently, the overflow control of drainage pipe networks adopts the approach of constructing large-scale storage facilities to absorb initial rainwater, and using system monitoring of liquid level and flow rate or setting fixed diversion times to determine the interception scheme.

[0003] Overflow control in drainage networks typically involves constructing large storage facilities to absorb initial rainwater runoff. Interception strategies are determined by monitoring liquid levels and flow rates and setting fixed diversion times. While expanding or modifying hardware facilities can alleviate hydraulic impact, it is difficult to achieve precise water quality response at the control level. For example, Chinese invention patent CN108265684B discloses an overflow tower for culverts. It addresses water hammer vibration and energy dissipation issues during overflow by optimizing the inner tower body and installing energy-dissipating grids, thereby improving the structural stability of the pipeline network. However, it focuses on fluid dynamics and physical defense, and its operating mechanism is a passive liquid level trigger mode. It lacks the ability to dynamically perceive the internal pollution load of the fluid. The blind overflow mechanism cannot separate the initial high-concentration flushing pollutants from the subsequent clean runoff, resulting in the storage capacity being occupied by low-pollution water bodies and high-load pollution being directly discharged into rivers, leading to low resource utilization and poor environmental benefits.

[0004] Therefore, how to select the physical oscillation characteristics generated by fluid flowing through a specific structure to characterize the pollution flux, so as to achieve accurate flow direction switching in an environment that does not rely on a precise detection window, has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a method for reducing pollution and utilizing resources from overflow in drainage pipe networks, comprising the following steps: Step 101: Install a non-circular flow disturbance unit at the inlet of the pipeline network. Use the vortex field generated by the fluid flowing through the non-circular flow disturbance unit to induce mechanical vibration signals in the pipe wall. Step 102: Use an acoustic detection unit installed outside the pipeline to collect mechanical vibration signals and extract the main frequency. Simultaneously, use two sets of non-contact electrodes set inside the pipeline to collect the conductivity signal of the fluid and obtain the instantaneous gradient of the conductivity signal. Step 103: Obtain the transmission delay of the conductivity signal between the two sets of non-contact electrodes, and calculate the real-time flow velocity of the fluid based on the transmission delay and the preset distance between the two sets of non-contact electrodes. Step 104: Perform frequency drift correction on the main oscillation frequency based on the real-time flow velocity to obtain the characteristic frequency deviation that reflects the viscosity characteristics of the fluid. Perform weighted calculation on the characteristic frequency deviation and the instantaneous gradient of the conductivity signal to generate the shunt characteristic value. Step 105, extract the frequency of the mechanical vibration signal that is within the range of... to The energy distribution within the interval is used to determine the scour intensity index. Step 106: Compare the diversion characteristic value with the preset water quality threshold, and compare the scouring intensity index with the preset scouring threshold; when the diversion characteristic value exceeds the preset water quality threshold, or the scouring intensity index exceeds the preset scouring threshold, the fluid is directed to the interception and storage facility by the execution unit; when the diversion characteristic value is lower than the preset water quality threshold and the scouring intensity index is lower than the preset scouring threshold, the fluid is directed to the resource utilization terminal.

[0006] Preferably, in step 101, the irregular turbulence unit is a wedge-shaped flow obstruction block fixed to the inner wall of the well inlet; the acoustic detection unit is a piezoelectric vibration acceleration sensor fitted to the outer surface of the pipeline.

[0007] Preferably, in step 103, the transmission delay is the signal time shift corresponding to the maximum value of the cross-correlation coefficient after performing cross-correlation calculation on the voltage signals collected by the two sets of non-contact electrodes.

[0008] Preferably, in step 104, the diversion characteristic value The calculation follows the formula below: ,in, For the diversion characteristic value, To determine the reference vibration frequency of rainwater at the corresponding real-time flow velocity, The dominant oscillation frequency, This represents the instantaneous gradient of the conductivity signal.

[0009] Preferably, in step 105, root mean square energy statistics are performed on the mechanical vibration signal to obtain the amplitude characteristics of the friction behavior of the corresponding bottom-deposited particles in the mechanical vibration signal, and the amplitude characteristics are defined as the scour intensity index.

[0010] Preferably, in step 106, when performing the flow path switching action, the instantaneous water hammer wave generated by the opening and closing of the switching valve is used to flush the surface of the irregular turbulence unit and the two sets of non-contact electrodes to remove the suspended deposits on the surface of the irregular turbulence unit and the two sets of non-contact electrodes.

[0011] Preferably, it also includes: monitoring the ambient background noise of the pipeline network during periods without rainfall, and performing signal-to-noise ratio compensation on the main oscillation frequency based on the mean of the ambient background noise.

[0012] Preferably, in step 106, when the diversion characteristic value remains below the preset water quality threshold for a continuous period of time and the real-time flow rate shows a monotonically decreasing trend, the collection branch leading to the rainwater reuse tank is opened by the execution unit.

[0013] Preferably, the two sets of non-contact electrodes are implemented by annular electrode sheets encapsulated inside the insulating liner of the inner wall of the pipeline, and the conductivity signal is obtained by detecting the change in induced current caused by the fluid passing through the cross section of the pipeline.

[0014] Preferably, in step 104, the overflow load is divided into heavy pollution, moderate pollution and light pollution according to the range of diversion characteristic values; when it is determined to be heavy pollution, the fluid is intercepted and diverted to the interception and storage facility by the execution unit.

[0015] Compared with existing technologies, the method for reducing and utilizing overflow pollution in drainage pipe networks according to the present invention has the following advantages: 1. In the reduction of overflow pollution in drainage pipe networks, the modulation effect of fluid micro-components on macroscopic physical fluctuation fields is utilized. By inducing the fluid to generate self-excited oscillating sound waves through asymmetric turbulence components set on the inner wall of the pipe network, the identification of pollutant concentration is transformed into physical monitoring of acoustic spectrum characteristics. Since the acoustic dominant frequency is affected by the fluid dynamic viscosity and density, the problem of detection window failure caused by biofilm coverage in traditional water quality sensors in sewage environments is avoided, ensuring that stable pollution load characterization parameters can still be obtained during long-term service.

[0016] 2. This invention achieves the correlation determination of flow velocity and pollution load through the synergistic effect of acoustic acquisition unit and conductivity electrode. The apparent flow velocity of the fluid is determined by the transmission delay of conductivity pulse sequence between different electrodes. This flow velocity characteristic is used to correct the frequency bias in the acoustic oscillation signal caused by fluid kinetic energy. Thus, the determination of pollution response factor can be consistent from the seepage stage to the rainstorm scouring stage. This solves the technical problem that it is difficult to distinguish between flow fluctuations and pollution pulses under complex flow conditions when monitoring a single physical quantity.

[0017] 3. This invention captures the initiation characteristics of sediment at the bottom of the pipe by independently extracting the low-frequency vibration component during the initial stage of rainfall when the pipe is not full. It utilizes the physical characteristic that the structural acoustic signal generated when solid particles at the bottom of the pipe roll or jump reaches its peak earlier than the chemical oxygen demand on the time axis, triggering the pre-diversion action before the water quality index changes. This control logic based on the sediment initiation intensity index transforms the system from a passive water quality response to an active stock prediction, eliminating the phenomenon of missed capture of initial rainwater pollution caused by the time difference of the execution unit response. Attached Figure Description

[0018] Fig. 1 This is a flowchart illustrating the implementation steps and logical control of a method for reducing and utilizing overflow pollution in drainage pipe networks according to the present invention. Fig. 2 This is a block diagram illustrating the hardware deployment architecture and signal interaction principle of the on-site monitoring and diversion control system of this invention. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0020] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0021] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0022] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0023] A method for reducing pollution and utilizing resources from overflow in drainage pipe networks includes several technical steps: fluid self-excited oscillation induction, multi-dimensional acoustic and electrical signal acquisition, flow velocity feature extraction and frequency compensation, decoupled calculation of pollution response factors, sediment initiation feedforward prediction, and closed-loop verification of execution unit actions. Each step forms a complete control closed loop through real-time data flow and physical feedback mechanisms. To address the detection failure of traditional water quality sensors in wastewater environments due to biofilm coverage, a uniquely shaped flow-disrupting unit is installed at the pipe network inlet, employing a wedge-shaped flow-blocking block fixed to the inner wall of the inlet chamber. When the fluid to be treated flows through this wedge-shaped flow-blocking block, the fluid generates periodic vortex shedding downstream, i.e., the Karman vortex street phenomenon, thereby inducing mechanical vibration signals on the pipe wall that are highly correlated with the fluid's dynamic viscosity and density. A piezoelectric vibration acceleration sensor, fitted to the outer surface of the pipe, is used to collect the mechanical vibration signals. A method based on Fast Fourier Transform is used to extract the energy peak value from the mechanical vibration signals, which is then determined as the dominant frequency. Since flow velocity fluctuations can cause frequency drift, a flow velocity compensation mechanism needs to be introduced to ensure the accuracy of the judgment. Simultaneously, two sets of non-contact electrodes set inside the pipeline are used to collect the conductivity signal of the fluid. These two sets of non-contact electrodes are composed of annular electrode sheets encapsulated inside the insulating lining of the inner wall of the pipeline.

[0024] Conductivity signals are obtained by detecting changes in induced current as fluid flows through the cross-section of a pipe; cross-correlation calculations are used to process the voltage signals collected by two sets of non-contact electrodes to determine the signal time shift corresponding to the maximum value of the cross-correlation coefficient, which is defined as the transmission delay. Based on transmission delay The preset spacing between the two sets of non-contact electrodes Determine the real-time flow rate of the fluid. Real-time flow rate The calculation formula is ; In obtaining real-time flow rate With the main oscillation frequency Then, pollution response factors were established. Decoupling model; calculation of instantaneous gradient of conductivity signal That is, in Continuous differential values ​​of conductivity signal amplitude within the sampling period; based on real-time flow velocity Regarding the dominant oscillation frequency Perform frequency drift correction to obtain shunt characteristic values; shunt characteristic values The calculation formula is as follows: ;in, For the diversion characteristic value, To determine the reference vibration frequency of rainwater at the corresponding real-time flow velocity, The dominant oscillation frequency, This represents the instantaneous gradient of the conductivity signal.

[0025] To address the risk of residual pollutants being introduced during the clean rainwater determination process due to channel volume issues, the system uses real-time flow velocity... Calculate the fluid transport hysteresis threshold To determine the physical delay of the flow channel switching, the pipeline length between the irregularly shaped flow disturbance unit and the execution unit is obtained. And according to the formula Calculate the fluid transport hysteresis threshold ,in, This is the fluid transport hysteresis threshold, in units of , Pipeline length, in units of , Real-time flow rate, unit: , The system employs a preset safety redundancy factor. To address the risk of reference drift caused by physical wear of the piping in the acoustic detection system, the offset is determined by calculating the centroid displacement of the main resonant peak position of the background acoustic signature. Extracting the background noise spectrum during non-rainfall periods. The amplitude-weighted average frequency is used as the real-time centroid frequency. And according to the formula Calculate the frequency offset; where, Frequency offset, in units of , For real-time center of gravity frequency, The initial center of gravity frequency, stored in the initialization configuration file during the initial deployment of the device, is used by the system to adjust the principal oscillation frequency. Perform linear corrections to maintain the shunt eigenvalues. Consistency in long-term judgments.

[0026] Example 1: In the overflow monitoring of combined sewer systems, the high concentration of pollution pulses generated at the beginning of rainfall in old urban areas causes the sediment at the bottom of the pipe to be stirred up. The resulting surge in suspended solids concentration causes the detection window of conventional optical water quality sensors to be blocked by deposits, making it impossible for the system to obtain effective pollution load parameters. Under this condition, the wedge-shaped flow obstruction block set on the inner wall of the pipe network inlet induces the fluid to be treated to generate periodic vortex shedding. The acoustic detection unit captures the mechanical vibration signal generated by the pipe wall and extracts the dominant frequency. Simultaneously, two sets of non-contact electrodes installed inside the pipeline are used to collect the conductivity signal of the fluid. The transmission delay of this conductivity signal between the two sets of non-contact electrodes is then utilized. Determine the real-time flow rate of the fluid. And based on the real-time flow rate Eliminate the dominant frequency The kinematic frequency components in the signal are used to obtain the characteristic frequency deviation reflecting the fluid's viscous properties. This deviation is then nonlinearly weighted and calculated with the instantaneous gradient of the conductivity signal to generate the shunt characteristic value. Diversion characteristic value The calculation formula is as follows: ,in, For the diversion characteristic value, To determine the reference vibration frequency of rainwater at the corresponding real-time flow velocity, The dominant oscillation frequency, The instantaneous gradient of the conductivity signal is given. Due to the physical complementarity between acoustic and electro-inductive features in the detection dimension, this parameter compensation mechanism enables the system to achieve quantitative perception of highly polluted fluids without relying on an optical window.

[0027] Taking advantage of the physical characteristic that pollutant concentrations peak later than runoff peaks during the initial stages of rainfall, the system extracts pollutants from mechanical vibration signals. to The low-frequency energy distribution within the interval is obtained by using root mean square energy statistics to obtain the amplitude characteristics within this frequency band and is defined as the scour intensity index. The system utilizes the structural acoustic waves generated by the particles at the bottom of the pipe during startup to perform feedforward judgment. When the scour intensity index is detected... When the preset flushing threshold is exceeded, the system adjusts the diversion characteristic value. Before the preset water quality threshold is reached, the execution unit is triggered to initiate a diversion action, directing the contaminated fluid to the interception channel. The physical water hammer pulse wave generated at the moment the switching valve opens and closes instantaneously flushes the wedge-shaped flow barrier and the surface of the non-contact electrode, removing the biofilm and particulate matter attached to the surface. As the rainfall duration increases and the diversion characteristic value rises... Once the water level drops back to the clean rainwater baseline, the system control unit switches the flow path to the resource utilization terminal to collect high-quality rainwater resources.

[0028] Example 2: In an experimental loop simulating the coupling characteristics of flow rate and pollution load in a drainage network, a flow velocity adjustment range of [missing information] was set up. to The experimental platform includes a variable frequency circulating pump and a simulated dosing device for gradient addition of suspended particles and organic oxygen-consuming substances; the data acquisition hardware of the experimental platform includes components that fit against the outer wall of the pipe and have a charge sensitivity of [missing information]. The piezoelectric accelerometer sensor, and the one encapsulated within the insulating layer of the inner wall of the pipe, with a sampling rate of Non-contact electrodes; to verify the stability of the scheme in a real engineering environment, a signal-to-noise ratio of [value missing] was actively superimposed on the original sensor signal. Additive white Gaussian noise is used to simulate structural vibration disturbances caused by surrounding traffic loads; time windows are considered in the cross-correlation calculations. The decision-making logic is set to balance the real-time response speed of flow velocity sensing with the signal-to-noise ratio of relevant peak identification. The decision-making logic follows this principle: when the instantaneous slope of the conductivity pulse sequence is detected... A lower level indicates high fluid homogeneity; in this case, increasing the time window is appropriate. to Each sampling point is used to suppress random noise through time gain; while the instantaneous slope When the slope exceeds the preset threshold, it indicates the presence of significant contaminant clusters within the fluid; in this case, the time window should be shortened. to Multiple sampling points were used to capture the instantaneous dynamics of the flow velocity. In the normal operating condition verification of this experiment, the time window was... The example value was determined as The experiment involved injecting simulated sediment and chemically oxygen-consuming components into the circulation loop at a proportional gradient to alter the fluid properties. A test group employing a complete acoustic-electric decoupling method and a control group lacking electrode velocity compensation were established for performance comparison. During the fluid's evolution from a clean state to a high-load contaminated state, vibration sensors were used to extract the main vortex shedding frequency induced by the wedge-shaped flow obstruction block in real time. The conductance pulses are captured synchronously by the electrode pair, and the propagation delay is determined based on the cross-correlation peak position. .

[0029] Table 1: Record of the evolution of characteristic parameters of the experimental group under different pollution gradients

[0030] Analysis of the experimental data in Table 1 shows that as the COD concentration in the fluid increases from... Increase to Diversion characteristic value Presented by to The monotonically increasing trend confirms that the pollutant components affect the dominant frequency by altering the fluid dynamic viscosity. The resulting physical damping effect; when the pollution load increases to the operating condition corresponding to serial number 5, the diversion characteristic value The growth rate of vortex shedding decreased significantly, exhibiting physical saturation characteristics. This indicates that fluid viscosity has degraded the coherence of vortex shedding. Meanwhile, the control group showed a decrease in flow velocity from... Change to During the transition process, due to the lack of transmission delay Regarding the dominant oscillation frequency The kinematic compensation, which generates shunt characteristic values More than The numerical fluctuations were observed, while the accuracy of the experimental group remained at the same level under the same environmental noise conditions. .

[0031] Example 3: This example combines Figs. 1-2 This describes a method for reducing pollution and utilizing resources from overflow in drainage pipe networks, such as... Fig. 1 As shown, step 101 involves installing a shaped turbulence unit at the inlet of the pipeline network to induce mechanical vibration signals in the pipe wall using the generated eddy current field. Step 102 involves extracting the dominant frequency using an acoustic detection unit and simultaneously acquiring the conductivity signal and instantaneous gradient using non-contact electrodes. Step 103 involves acquiring the transmission delay of the conductivity signal between the non-contact electrodes and calculating the real-time flow velocity of the fluid based on the delay and the electrode spacing. Step 104 involves correcting the dominant frequency based on the real-time flow velocity to obtain the characteristic frequency deviation and weighting it with the instantaneous conductivity gradient to generate a diversion characteristic value. Step 105 involves extracting the energy distribution in the 20Hz to 200Hz range of the mechanical vibration signal and determining the scouring intensity index based on the energy distribution. Finally, step 106 involves comparing the diversion characteristic value and the scouring intensity index with thresholds, and then using the execution unit to guide the fluid to an interception and storage facility or a resource utilization terminal.

[0032] like Fig. 2 As shown, the on-site monitoring area is located at the inlet node of the pipeline network. At the cross-section of the drainage pipeline, there are irregularly shaped flow disturbance units that act as wedges on the inner wall of the pipe, non-contact electrode groups embedded in the insulating liner, and acoustic detection units attached to the outer wall of the pipe. The conductivity and vibration signals collected by the above components under the action of fluid input are transmitted to the data processing and control center, which is an edge computing terminal. Inside, a multi-dimensional signal synchronous acquisition module, a core decoupling operation module including flow velocity correction and frequency drift compensation, a feature extraction and fusion module involving diversion characteristic values ​​and scour intensity index, and an intelligent decision-making logic module including multi-threshold comparison and state arbitration are run in sequence to finally generate an execution command output. The flow path switching command is sent to the execution and diversion terminal to control the execution unit, which acts as an electric switching valve or gate. According to the command, the fluid is intercepted for pollution and guided to the interception and storage facility for storing highly polluted fluid, or it is collected for resource utilization and guided to the resource utilization terminal for storing clean rainwater.

[0033] Example 4: A detection system is deployed at the pipe network nodes of a newly built drainage zone. During the first dry season before operation, a self-learning calibration procedure is initiated. The acoustic detection unit continuously collects mechanical vibration signals generated by the flow of domestic sewage, and the mechanical vibration signals are processed according to… The flow velocity step intervals are classified and aggregated. The most frequent characteristic peak in each flow velocity interval is extracted and determined as the median vibration frequency at that flow velocity. The system uses a cubic spline interpolation algorithm to process each flow velocity point to generate a reference frequency mapping table for the corresponding drainage zone. The reference frequency mapping table is used to determine the reference vibration frequency under different flow velocity conditions. .

[0034] The system acquires real-time diversion characteristic values ​​during dry weather cycles. Perform probability distribution statistics and calculate the sample mean within the specified period. with standard deviation The system sets the preset water quality threshold to ,in, The mean of the dry-day diversion characteristic value, The standard deviation of the dry-day diversion characteristic value is given by the diversion characteristic value. The calculation formula is as follows: ,in, For the diversion characteristic value, To determine the reference vibration frequency of rainwater at the corresponding real-time flow velocity, The dominant oscillation frequency, The instantaneous gradient of the conductivity signal is used as the dynamic threshold determination method, which adjusts the judgment boundary based on the background load fluctuations of different pipeline network locations. The system receives the gate operation acoustic fingerprint fed back by the acoustic detection unit and drives the execution unit to operate at full opening. to Execution frequency within the range is The reciprocating opening and closing motion, with the number of cycles set to [number]. Next, the fluid shock wave generated by this reciprocating motion is used to peel off the biofilm on the surface of the irregularly shaped turbulent unit. The system compares the main oscillation frequency in the first detection cycle after the motion ends. The signal-to-noise ratio (SNR) was deemed insufficient to improve the signal-to-noise ratio. The system triggers a secondary reciprocating oscillation action, where the signal-to-noise ratio is the ratio of the characteristic frequency energy value to the background noise energy value. This physical feedback-based maintenance procedure establishes a state correlation between the detection system and the actuator.

[0035] Example 5: The system deployment procedure is executed at the physical nodes of the pipe network in the newly built drainage zone. Due to the different acoustic resonance characteristics of pipes of different materials and diameters, the system will be activated after installation for a period of time. Hourly baseline feature scans are performed, and the acoustic detection unit acquires the pipeline background noise spectrum during periods when the flow rate is below a preset threshold. Obtain the ambient noise baseline value, and inject a frequency of [value] into the non-contact electrode pair. And the amplitude is The high-frequency excitation signal was used to measure the empty tube voltage response caused by stray capacitance. This voltage response serves as the zero-point compensation for subsequent conductivity calculations, where Represents the background noise spectrum. To obtain the empty pipe voltage response, the system writes the acquired physical characteristic parameters into a configuration file in local memory, establishing the physical attribute fingerprint of the node. Before monitoring operation, the system executes a gradient calibration procedure to fill the flow velocity-frequency mapping table, and controls the fluid velocity flowing through the irregularly shaped turbulent unit via a variable frequency pump station. to The flow rate increases at a constant rate, with the flow rate step set to... The acoustic detection unit continuously operates at each speed step. The dominant frequency was then acquired. Calculate the frequency variance within this period. Determine the frequency variance Less than At that time, the system records the average of the principal vibration frequency as the reference vibration frequency. .

[0036] To eliminate the influence of pipe inner wall roughness and fluid Reynolds number variations on the nonlinear characteristics of the Strouhal number, a velocity-frequency reference mapping table needs to be constructed to determine the reference vibration frequency under clean rainwater conditions. The specific procedures are as follows: Select a dry period with no rainfall, confirm that the fluid in the pipeline is domestic sewage as the base flow and that the liquid level is at full capacity, control the upstream pump station or regulating valve to adjust the flow velocity of the fluid flowing through the irregularly shaped turbulent unit. from Starting with For flow rate stepping Gradually increase to the maximum design flow rate Maintain at each flow rate step In a stable flow state, mechanical vibration signals are continuously acquired over a time period using an acoustic detection unit, and a Fast Fourier Transform (FFT) is performed to calculate the variance of the main peak frequency of the spectrum within the time window. ,like If the flow regime is determined to be stable, the main peak frequency is recorded as the measured reference frequency at the current flow velocity. Then extend the sampling time until the variance converges, and traverse all flow velocity steps to obtain a discrete data point set. The least squares method is used to fit a cubic polynomial to the data point set to generate a continuous reference frequency function. The data is stored in the non-volatile memory of the edge computing terminal. The system uses a linear interpolation algorithm to process undefined velocity points between steps and generate a lookup table covering the entire range.

[0037] Meanwhile, the system analyzes the diversion characteristic values ​​acquired in real time during the calibration period. Perform probability distribution statistics and calculate the sample mean. with standard deviation Set the preset water quality threshold to ,in, For frequency variance, As the reference vibration frequency, For the diversion characteristic value, The sample mean. The calibration procedure establishes a mapping relationship between the detected physical quantity and the logical discrimination boundary, using the standard deviation as the standard deviation. The system executes the self-maintenance procedure of the unit through a physical feedback mechanism. The acoustic detection unit captures the acoustic signature characteristics generated by the switching valve's action and performs a consistency check, determining that the cross-correlation coefficient is lower than the standard deviation. At that time, the system drive execution unit is at full open. to Execution frequency within the range is The reciprocating opening and closing motion, with the number of cycles set to [number]. Next, the fluid shock wave generated by this action washes over the surface of the irregularly shaped turbulence unit, stripping away the attached suspended particles. After the action is completed, the dominant frequency is monitored. The signal-to-noise ratio (SNR) was deemed insufficient to improve the signal-to-noise ratio. At that time, the reciprocating opening and closing action is repeatedly executed.

[0038] Example 6: In an inner diameter of The merging interceptor well node executes an installation tilt angle calibration procedure for the irregularly shaped flow disturbance unit to suppress the interference of local flow field turbulence on the extraction of sensing features and to determine the signal gain under the physical excitation field. The system controls the installation tilt angle of the wedge-shaped flow obstruction block relative to the pipe axis. Using steps as exist to Transformation is performed within the interval, simultaneously at a flow velocity of Mechanical vibration signals of the pipe wall were collected under clean runoff conditions, and the ratio of characteristic peak power to average noise power in the surrounding frequency band was calculated to determine the dominant frequency. The signal-to-noise ratio value at the installation tilt angle; for Time signal-to-noise ratio is When installing tilt angle Set as Time signal-to-noise ratio is When installing tilt angle Increase to The signal-to-noise ratio then dropped to The system uses this to determine the installation tilt angle of the node. Determined as And then, the physical property parameter is stored in local memory.

[0039] When the detection system encounters a situation where acoustic transmission energy attenuation is caused by the accumulation of deposits on the pipe wall, the system activates an online signal-to-noise ratio monitoring program to perform adaptive correction of the discrimination logic and ensure the shunt characteristic value. The calculation accuracy; extracting the mechanical vibration signal from the state of... to The root mean square energy value of the interval is used as the reference power for environmental noise. And based on the dominant oscillation frequency Signal power density at Calculate real-time signal-to-noise ratio ;in, Signal-to-noise ratio, unit: , For signal power density, As the ambient noise reference power, when the system determines the signal-to-noise ratio continuous The number of monitoring cycles is less than At that time, the system will automatically assign the diversion characteristic value The sliding decision window is extended to The sampling period utilizes the time integration effect to suppress numerical fluctuations caused by random flow noise and maintain the reliability of a method for reducing pollution and utilizing resources in drainage network overflows.

[0040] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A method for reducing pollution and utilizing resources from overflow in drainage pipe networks, characterized in that, Includes the following steps: Step 101: Install a non-circular flow disturbance unit at the inlet of the pipeline network. Use the vortex field generated by the fluid flowing through the non-circular flow disturbance unit to induce mechanical vibration signals in the pipe wall. Step 102: Use an acoustic detection unit installed outside the pipeline to collect mechanical vibration signals and extract the main frequency. Simultaneously, use two sets of non-contact electrodes set inside the pipeline to collect the conductivity signal of the fluid and obtain the instantaneous gradient of the conductivity signal. Step 103: Obtain the transmission delay of the conductivity signal between the two sets of non-contact electrodes, and calculate the real-time flow velocity of the fluid based on the transmission delay and the preset distance between the two sets of non-contact electrodes. Step 104: Perform frequency drift correction on the main oscillation frequency based on the real-time flow velocity to obtain the characteristic frequency deviation that reflects the viscosity characteristics of the fluid. Perform weighted calculation on the characteristic frequency deviation and the instantaneous gradient of the conductivity signal to generate the shunt characteristic value. Step 105, extract the frequency of the mechanical vibration signal that is within the range of... to The energy distribution within the interval is used to determine the scour intensity index. Step 106: Compare the diversion characteristic value with the preset water quality threshold, and compare the scouring intensity index with the preset scouring threshold; when the diversion characteristic value exceeds the preset water quality threshold, or the scouring intensity index exceeds the preset scouring threshold, the fluid is directed to the interception and storage facility by the execution unit; when the diversion characteristic value is lower than the preset water quality threshold and the scouring intensity index is lower than the preset scouring threshold, the fluid is directed to the resource utilization terminal.

2. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 101, the irregular flow disturbance unit is a wedge-shaped flow obstruction block fixed to the inner wall of the well inlet; the acoustic detection unit is a piezoelectric vibration acceleration sensor that is attached to the outer surface of the pipeline.

3. The method for reducing and utilizing pollution from overflow in drainage pipe networks according to claim 1, characterized in that, In step 103, the transmission delay is the signal time shift corresponding to the maximum value of the cross-correlation coefficient after performing cross-correlation calculation on the voltage signals collected by the two sets of non-contact electrodes.

4. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 104, the diversion characteristic value The calculation follows the formula below: ,in, For the diversion characteristic value, To determine the reference vibration frequency of rainwater at the corresponding real-time flow velocity, The dominant oscillation frequency, This represents the instantaneous gradient of the conductivity signal.

5. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 105, root mean square energy statistics are performed on the mechanical vibration signal to obtain the amplitude characteristics of the friction behavior of the corresponding bottom deposited particles in the mechanical vibration signal, and the amplitude characteristics are defined as the scour intensity index.

6. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 106, when performing the flow path switching action, the instantaneous water hammer wave generated by the opening and closing of the switching valve is used to flush the surface of the irregular turbulence unit and the two sets of non-contact electrodes to remove the suspended deposits on the surface of the irregular turbulence unit and the two sets of non-contact electrodes.

7. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, Also includes: During periods without rainfall, the ambient background noise of the pipeline network is monitored, and the signal-to-noise ratio is compensated for the main oscillation frequency based on the mean of the ambient background noise.

8. The method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 106, when the diversion characteristic value remains below the preset water quality threshold for a continuous period of time and the real-time flow rate shows a monotonically decreasing trend, the collection branch leading to the rainwater reuse tank is opened by the execution unit.

9. A method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, Two sets of non-contact electrodes are implemented through annular electrode sheets encapsulated inside the insulating liner of the pipeline. The conductivity signal is obtained by detecting the change in induced current caused by fluid passing through the pipeline cross section.

10. A method for reducing pollution and utilizing resources from overflow in drainage pipe networks according to claim 1, characterized in that, In step 104, the overflow load is divided into heavy pollution, moderate pollution and light pollution according to the range of diversion characteristic values; when it is determined to be heavy pollution, the entire fluid is diverted to the interception and storage facility through the execution unit.

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