Intelligent control method and system for wet treatment of sewer sludge

Abstract

This application provides an intelligent control method and system for wet treatment of sludge in drainage pipes and channels. The method constructs a particle size attenuation spectrum of the sludge in the drainage pipes and channels based on ultrasonic echo information from the conical section of a hydrocyclone. When the attenuation value of a characteristic frequency band in the particle size attenuation spectrum exceeds a preset abrupt change threshold, the characteristic particle size value of the current abrupt change frequency band is determined. Based on the characteristic particle size value, the upward flow resistance increment and the diameter of the hydrocyclone's underflow outlet required to maintain boundary layer stability are adjusted using a reverse gradient. When the particle size attenuation spectrum after reverse gradient adjustment returns to a layered distribution increasing from top to bottom, and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is all less than or equal to the preset abrupt change threshold, the current underflow outlet diameter remains unchanged until the next round of instability occurs. Based on the above scheme, early prediction of instability phenomena inside the hydrocyclone can be achieved, thereby improving the stability control capability of the staged separation process.

Description

Technical Field

[0001] This application relates to the field of sludge treatment technology, and more specifically, to an intelligent control method and system for wet treatment of sludge in drainage pipes and channels. Background Technology

[0002] Drainage pipe networks are channels in urban drainage systems used to collect and transport rainwater, sewage, and domestic wastewater. They include drainage pipes, culverts, covered ditches, and their ancillary structures. During long-term operation, impurities such as silt, garbage, and organic matter carried in the water will accumulate at the bottom of the pipes and channels, forming sludge. Regularly cleaning this sludge is a necessary maintenance task to ensure the smooth operation of the drainage system.

[0003] In conventional wet sludge treatment monitoring methods for drainage pipes, turbidity meters and concentration meters can only be installed on external output pipes such as the overflow pipe or underflow outlet of the hydrocyclone to measure the total content of solid particles in the final discharged material. These methods only reflect a comprehensive result after the entire separation process and cannot penetrate the equipment casing to directly obtain real-time status information inside the hydrocyclone's conical section. When turbidity or concentration data shows an abnormal increase, it often means that a large amount of fine sand particles that should have settled have broken through the classification boundary layer, overflowing and flowing away. At this point, instability has already occurred, and substandard material has been produced. Operators cannot detect the abnormality and make predictions or intervene in advance before the fine sand begins to float up at the classification boundary layer and before product quality deteriorates. This is a typical post-event feedback control mode. Therefore, how to achieve early prediction of instability within the hydrocyclone, thereby improving the stability control capability of the classification separation process, has become a challenge for the industry. Summary of the Invention

[0004] This application provides an intelligent control method and system for wet treatment of sludge in drainage pipes and channels, which can realize early prediction of instability phenomena inside hydrocyclones, thereby improving the stability control capability of the staged separation process.

[0005] In a first aspect, this application provides an intelligent control method for wet treatment of sludge in drainage pipes and channels. In the separation of fine sand (0.1 to 10 mm) during wet treatment of sludge in drainage pipes and channels, a hydrocyclone identifies the floating instability of fine sand during wet treatment by monitoring the ultrasonic particle size attenuation spectrum within its conical section. The method includes:

[0006] The ultrasonic echo information in the conical section of the hydrocyclone is monitored, and then the particle size attenuation spectrum of the sludge in the drainage pipe is constructed based on the ultrasonic echo information.

[0007] When the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than the preset abrupt change threshold, and the corresponding attenuation direction is propagating countercurrently from the low cross section to the high cross section, it is determined that the graded boundary layer is experiencing an instability phenomenon of fine sand floating up, and then the characteristic particle size value of the characteristic frequency band of the current abrupt change is determined.

[0008] Based on the characteristic particle size value, the upward flow resistance increment and the underflow diameter of the hydrocyclone required to maintain boundary layer stability are adjusted in reverse gradient to obtain the particle size attenuation spectrum after each reverse gradient adjustment.

[0009] When the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom, and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to the preset mutation threshold, the current underflow diameter remains unchanged until the next round of instability occurs.

[0010] In some embodiments, an ultrasonic transceiver array is used to monitor ultrasonic echo information in the conical section of a hydrocyclone.

[0011] In some embodiments, constructing the particle size attenuation spectrum of sewage sludge in drainage pipes based on the ultrasonic echo information specifically includes:

[0012] The theoretical attenuation values ​​of ultrasound waves in clear water at different frequency bands are pre-calibrated to obtain a reference attenuation.

[0013] Extract the echo attenuation of each cross section from the ultrasonic echo information;

[0014] The echo attenuation of each cross section is compared with the reference attenuation of the corresponding frequency band to obtain the additional attenuation value caused by sludge particles in each frequency band.

[0015] The particle size attenuation spectrum of the sludge in the drainage pipes was determined by using all additional attenuation values.

[0016] In some embodiments, the instability phenomenon is the process by which fine sand particles in the graded boundary layer overcome the resistance of the upward water flow, migrate toward the overflow outlet, and cause fine sand loss, thus affecting the sand removal effect.

[0017] In some embodiments, determining the characteristic particle size value of the characteristic frequency band of the current mutation specifically includes:

[0018] Identify the characteristic frequency segment with the largest abrupt change in attenuation value in the particle size attenuation spectrum, and obtain the principal reflection frequency of the unstable particle corresponding to the current abrupt change frequency segment;

[0019] Based on the inverse relationship between ultrasonic frequency and particle size, the upper limit frequency of the abrupt frequency band is converted into the corresponding minimum particle size, and the lower limit frequency is converted into the corresponding maximum particle size.

[0020] The characteristic particle size value of the characteristic frequency band of the current mutation is determined based on the minimum particle size and the maximum particle size.

[0021] In some embodiments, the reverse gradient adjustment of the upstream flow resistance increment and the hydrocyclone underflow orifice diameter required to maintain boundary layer stability based on the characteristic particle size value specifically includes:

[0022] The particle size range of the current unstable fine sand is determined based on the characteristic particle size value. Then, the gradient adjustment of the upward water flow resistance increment is performed based on the particle size range, and the diameter of the hydrocyclone bottom outlet is gradually increased according to the preset gradient step size.

[0023] After each adjustment, the particle size attenuation spectrum is re-acquired. If the attenuation value in the unstable characteristic frequency range continues to decrease, the adjustment in the same direction is continued.

[0024] If the attenuation value no longer decreases or worsens in the opposite direction, the adjustment amount of the previous step is reversed and the current diameter is locked, thus completing the reverse gradient adjustment of the upward water flow resistance increment and the diameter of the hydrocyclone underflow outlet.

[0025] In some embodiments, the mutation threshold is an upper boundary value based on the statistical distribution of particle size attenuation spectrum under historical stable operating conditions.

[0026] Secondly, this application provides an intelligent control system for wet treatment of sludge in drainage pipes and channels, including a control unit, the control unit comprising:

[0027] The monitoring module is used to monitor the ultrasonic echo information in the conical section of the hydrocyclone, and then construct the particle size attenuation spectrum of the sludge in the drainage pipe based on the ultrasonic echo information.

[0028] The processing module is used to determine that the graded boundary layer is experiencing instability due to fine sand floating when the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than a preset abrupt change threshold and the corresponding attenuation direction is reverse propagating from the low cross section to the high cross section, and then to determine the characteristic particle size value of the characteristic frequency band of the current abrupt change.

[0029] The processing module is also used to perform reverse gradient adjustment on the upstream flow resistance increment and hydrocyclone underflow orifice diameter required to maintain boundary layer stability based on the characteristic particle size value, and to obtain the particle size attenuation spectrum after each reverse gradient adjustment.

[0030] The execution module is used to maintain the current underflow diameter unchanged until the next round of instability occurs after the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to a preset mutation threshold.

[0031] Thirdly, this application provides a computer device, which includes a memory and a processor. The memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the computer device executes the above-mentioned intelligent control method for wet treatment of sewage sludge in drainage pipes and channels.

[0032] Fourthly, this application provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to implement the aforementioned intelligent control method for wet treatment of sludge in drainage pipes and channels.

[0033] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects:

[0034] This application provides an intelligent control method and system for wet treatment of sludge in drainage pipes and channels. The method monitors ultrasonic echo information in the conical section of a hydrocyclone, and then constructs a particle size attenuation spectrum of the sludge in the drainage pipes and channels based on the ultrasonic echo information. When the attenuation value of a characteristic frequency segment in the particle size attenuation spectrum is greater than a preset abrupt change threshold, and the corresponding attenuation direction propagates counter-currently from the lower cross-section to the upper cross-section, it is determined that the graded boundary layer is experiencing instability due to fine sand buoyancy, and the characteristic particle size value of the current abrupt change frequency segment is determined. Based on the characteristic particle size value, the upward flow resistance increment and the diameter of the hydrocyclone's underflow outlet required to maintain boundary layer stability are adjusted using a reverse gradient, and the particle size attenuation spectrum after each reverse gradient adjustment is obtained. When the particle size attenuation spectrum recovers to a layered distribution increasing from top to bottom, and the attenuation value of each characteristic frequency segment in the particle size attenuation spectrum is all less than or equal to the preset abrupt change threshold, the current underflow outlet diameter remains unchanged until the next round of instability occurs.

[0035] Therefore, in this application, when the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom, and the attenuation values ​​of all characteristic frequency bands in the particle size attenuation spectrum are all less than or equal to the preset mutation threshold, the current underflow diameter remains unchanged until the next round of instability occurs. First, determining the characteristic particle size value yields the typical particle size of the unstable fine sand. The balance between the upward water flow drag force and the settling gravity experienced by fine sand particles of different sizes in the graded boundary layer is significantly different. Determining the characteristic particle size value allows the control system to quantify the typical diameter of the fine sand particles that float in the current instability. Determining the characteristic particle size value establishes a direct correlation between the adjustment action and the actual physical characteristics of the unstable particles, avoiding the problems of over-adjustment or under-adjustment, thereby improving the accuracy and convergence speed of the reverse gradient adjustment and creating conditions for the rapid recovery of the graded boundary layer stability. Then, determining the particle size attenuation spectrum yields the frequency attenuation distribution of sludge particles along the axial direction of the cone section, thereby realizing... The current method continuously monitors the boundary layer state and identifies early signs of instability. The particle size attenuation spectrum, with frequency on the horizontal axis and attenuation value on the vertical axis, presents the relative content of particles in different size ranges at different cross-sections within the conical section of the hydrocyclone as a curve. The low-frequency attenuation value reflects the distribution of large-diameter fine sand, while the high-frequency attenuation value reflects the distribution of small-diameter fine sand. By comparing the attenuation values ​​at different frequencies within the same cross-section and the attenuation values ​​at the same frequency within different cross-sections, it is possible to detect in real time whether the normal stratified distribution of particle size along the axial direction has been disrupted. When the attenuation spectrum shows a counter-current propagation characteristic of decreasing low-frequency attenuation values ​​at low cross-sections and increasing low-frequency attenuation values ​​at high cross-sections, this early abnormal signal can be captured before a large amount of fine sand enters the overflow product. This overcomes the limitation of traditional monitoring methods that can only provide feedback after the fact, enabling early prediction of instability phenomena. In summary, based on the above scheme, early prediction of instability phenomena inside the hydrocyclone can be achieved, thereby improving the stability control capability of the classification and separation process. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0037] Figure 1 This is an exemplary flowchart of an intelligent control method for wet treatment of sludge in drainage pipes and channels, according to some embodiments of this application.

[0038] Figure 2 This is a schematic diagram of the process flow of a wet treatment system for sludge in drainage pipes and channels, according to some embodiments of this application.

[0039] Figure 3 This is a flowchart illustrating the implementation of reverse gradient adjustment according to some embodiments of this application;

[0040] Figure 4 This is a schematic diagram of the structure of a control unit according to some embodiments of this application;

[0041] Figure 5 This is a schematic diagram of the structure of a computer device for implementing an intelligent control method for wet treatment of sludge in drainage pipes and channels, according to some embodiments of this application. Detailed Implementation

[0042] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] refer to Figure 1 The figure is an exemplary flowchart of an intelligent control method for wet treatment of sludge in drainage pipes and channels, according to some embodiments of this application. The intelligent control method for wet treatment of sludge in drainage pipes and channels mainly includes the following steps:

[0044] In step 101, the ultrasonic echo information in the conical section of the hydrocyclone is monitored, and then the particle size attenuation spectrum of the sludge in the drainage pipe is constructed based on the ultrasonic echo information.

[0045] It should be noted that in this application, an ultrasonic transceiver array is used to monitor the ultrasonic echo information in the conical section of the hydrocyclone; the ultrasonic echo information is an ultrasonic dynamic signal that reflects the intensity of ultrasonic reflection and scattering by solid particles in the sludge.

[0046] In practice, multiple sets of ultrasonic transceiver probes are evenly spaced along the axial direction on the outer side of the conical section of the hydrocyclone. Each set of probes includes one transmitting probe and one receiving probe. The transmitting probe emits broadband ultrasonic pulses into the sludge inside the conical section, close to the outer wall of the section. The frequency range of these pulses covers a continuous distribution from low to high frequencies. When the pulses encounter solid particles of different sizes during propagation in the sludge, they are reflected and scattered. The receiving probe collects the returned ultrasonic dynamic signals and converts them into electrical signals. The collected electrical signals are decomposed according to frequency from low to high to obtain the echo energy values ​​of each frequency band. The difference between the initial energy of the transmitted pulse and the echo energy value in each frequency band is calculated as the echo amplitude attenuation of that frequency band. The echo amplitude attenuation of each frequency band in the same cross section is arranged from low to high frequency to form a curve with frequency as the horizontal axis and attenuation value as the vertical axis. This curve is used as the original echo information of that cross section.

[0047] It should be noted that in this application, Figure 2This diagram illustrates the process flow of a wet treatment system for sludge from drainage pipes and channels. The sludge discharged from the drainage system first enters a coarse screening device, where particles larger than 100 mm are screened and transported directly off-site. The undersize material enters a fine screening device and undergoes coarse washing, while simultaneously being washed with recycled water to separate particles between 10 and 100 mm, which are then transported off-site. The sand-water mixture after fine screening is then fed into a hydrocyclone for grading and separation. The underflow from the hydrocyclone enters a sand-water separator, producing fine sand with a particle size of 0.1 to 10 mm, which is then transported off-site. The overflow from the hydrocyclone and the effluent from the sand-water separator are then fed into a wastewater treatment unit, where they are treated to meet discharge standards.

[0048] In some embodiments, constructing the particle size attenuation spectrum of sewage sludge in drainage pipes based on the ultrasonic echo information can be achieved through the following steps:

[0049] The theoretical attenuation values ​​of ultrasound waves in clear water at different frequency bands are pre-calibrated to obtain a reference attenuation.

[0050] Extract the echo attenuation of each cross section from the ultrasonic echo information;

[0051] The echo attenuation of each cross section is compared with the reference attenuation of the corresponding frequency band to obtain the additional attenuation value caused by sludge particles in each frequency band.

[0052] The particle size attenuation spectrum of the sludge in the drainage pipes was determined by using all additional attenuation values.

[0053] It should be noted that, in this application, the reference attenuation is a set of attenuation values ​​at different frequency bands that reflect the natural attenuation of ultrasonic energy in clear water as the propagation distance increases; the echo attenuation is the energy difference that characterizes the total energy loss of the ultrasonic pulse from transmission to reception; the additional attenuation value is used to quantify the difference between the additional absorption and scattering of ultrasonic waves by solid particles in sludge; and the particle size attenuation spectrum is a curve that reflects the distribution characteristics of particles of different sizes in sludge.

[0054] In practice, firstly, with the hydrocyclone not operating and the conical section completely filled with clean water and free of any sludge particles, the ultrasonic transceiver array is activated. The control system sequentially triggers the transmitting probes at each section, with each probe emitting a broadband ultrasonic pulse into the clean water. The receiving probe collects the ultrasonic motion signal returned after propagation through the clean water, converts it into an electrical signal, and transmits it to the data processing unit. The data processing unit decomposes the electrical signal collected at each section according to frequency from low to high, obtaining the clean water echo energy value at each frequency band. The difference between the initial energy of the transmitted pulse and the clean water echo energy value at each frequency band is calculated; this difference is the theoretical attenuation value at that frequency band under clean water conditions. The above calculation is repeated for all frequency bands to obtain the theoretical attenuation values ​​at each frequency band from low to high frequency. All theoretical attenuation values ​​are then sorted according to frequency from low to high. The data are arranged sequentially into a reference table, which serves as the baseline attenuation reference. Next, the raw echo information collected from each cross-section under sludge conditions is read from the data processing unit. The raw echo information for each cross-section has been decomposed into echo energy values ​​in each frequency band. For any cross-section, the echo energy value of each frequency band is extracted. The difference between the initial energy of the transmitted pulse and the echo energy value in that frequency band is calculated; this difference is the echo attenuation of that cross-section in that frequency band. This calculation is repeated for all cross-sections and all frequency bands to obtain the echo attenuation of each cross-section in each frequency band. The set of all echo attenuation values ​​is taken as the echo attenuation of each cross-section. Then, the echo attenuation of a specific cross-section at a certain frequency band is taken out, and the theoretical attenuation value corresponding to the same frequency band is found from the reference attenuation. The theoretical attenuation value is subtracted from the echo attenuation value, and the difference is the additional attenuation value caused by sludge particles at that frequency band for that cross-section. The above subtraction operation is performed on all cross-sections and all frequency bands one by one to obtain the additional attenuation value of each cross-section in each frequency band. The additional attenuation value of the first cross-section in the 100 kHz frequency band is taken as the solid particle contribution at that location and frequency band, the additional attenuation value of the first cross-section in the 500 kHz frequency band is taken as the solid particle contribution at that location and frequency band, and so on, to obtain the additional attenuation value of all cross-sections. The set of additional attenuation values ​​across all frequency bands is obtained. Finally, the additional attenuation values ​​corresponding to each frequency band on a certain cross section are selected. The additional attenuation value corresponding to the lowest frequency band is placed on the far left, the additional attenuation value corresponding to the second lowest frequency band is placed on its right, and so on, until the additional attenuation value corresponding to the highest frequency band is placed on the far right. This yields a curve with frequency as the horizontal axis and additional attenuation value as the vertical axis. Observe this curve: if the additional attenuation value in the low-frequency band is high and the additional attenuation value in the high-frequency band is low, it indicates that large-diameter particles account for a large proportion on this cross section; if the additional attenuation value in the low-frequency band is low and the additional attenuation value in the high-frequency band is high, it indicates that small-diameter particles account for a large proportion on this cross section.Output the curve as the particle size attenuation spectrum of that section; repeat the above steps to obtain the particle size attenuation spectrum corresponding to each section, and use the set of all particle size attenuation spectra as the particle size attenuation spectrum of the sludge in the drainage pipes.

[0055] In step 102, when the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than a preset abrupt change threshold, and the corresponding attenuation direction is propagating countercurrently from the low cross section to the high cross section, it is determined that the graded boundary layer is experiencing an instability phenomenon of fine sand floating up, and then the characteristic particle size value of the characteristic frequency band of the current abrupt change is determined.

[0056] It should be noted that in this application, when the hydrocyclone is running normally and stably, particles of different sizes in the sludge are distributed regularly along the axial direction of the cone section. Large-sized fine sand is concentrated in the low-section area due to its fast settling velocity, while small-sized fine sand is distributed in the high-section area with the upward water flow. This is reflected in the particle size attenuation spectrum as a normal layered distribution with high attenuation values ​​in the low-frequency section of the low section and low attenuation values ​​in the low-frequency section of the high section. When the graded boundary layer becomes unstable, the fine sand particles that should have settled overcome the resistance of the upward water flow and migrate to the high section, resulting in a decrease in the fine sand content in the low section and an increase in the fine sand content in the high section. Here, large-sized fine sand refers to fine sand of 1-10 mm, and small-sized fine sand refers to fine sand of 0.1-1 mm.

[0057] In practice, the data processing unit arranges the particle size attenuation spectrum obtained from real-time monitoring of each cross section in ascending order of cross section position. For each characteristic frequency band, it compares the attenuation values ​​of two adjacent cross sections sequentially upwards from the lowest cross section and records the direction of change of the attenuation value. When it is found that the attenuation value of a certain characteristic frequency band increases instead of decreasing in the direction from the low cross section to the high cross section, and the magnitude of this increase exceeds the preset abrupt change threshold, the characteristic frequency band is marked as an abnormal frequency band, and the attenuation propagation direction corresponding to the abnormal frequency band is determined to be countercurrent propagation from the low cross section to the high cross section. Based on the determination results of all abnormal frequency bands, as long as at least one characteristic frequency band simultaneously meets the two conditions of attenuation value greater than the abrupt change threshold and propagation direction being countercurrent propagation, it is determined that the graded boundary layer is experiencing instability due to fine sand uplift.

[0058] Additionally, it should be noted that in this application, the instability phenomenon refers to the process by which fine sand particles in the graded boundary layer overcome the resistance of the upward water flow, migrate towards the overflow outlet, and cause fine sand loss, affecting the sand removal effect. The mutation threshold is the upper limit boundary value based on the statistical distribution of particle size attenuation spectrum under historical stable operating conditions. Specifically, it can be preset in the following way: collect particle size attenuation spectrum data of the hydrocyclone under normal operation and no instability conditions for multiple sampling periods, calculate the statistical mean and standard deviation of the attenuation value in each characteristic frequency band, and use the mean plus three times the standard deviation as the dynamic mutation threshold of that frequency band. The dynamic mutation thresholds of each frequency band together constitute a threshold curve that changes with frequency, which serves as the benchmark for real-time judgment. If the measured attenuation value of any frequency band exceeds the threshold corresponding to that frequency band, the instability judgment condition is triggered.

[0059] In some embodiments, determining the characteristic particle size value of the characteristic frequency band of the current mutation can be achieved by the following steps:

[0060] Identify the characteristic frequency segment with the largest abrupt change in attenuation value in the particle size attenuation spectrum, and obtain the principal reflection frequency of the unstable particle corresponding to the current abrupt change frequency segment;

[0061] Based on the inverse relationship between ultrasonic frequency and particle size, the upper limit frequency of the abrupt frequency band is converted into the corresponding minimum particle size, and the lower limit frequency is converted into the corresponding maximum particle size.

[0062] The characteristic particle size value of the characteristic frequency band of the current mutation is determined based on the minimum particle size and the maximum particle size.

[0063] It should be noted that, in this application, the main reflection frequency is the frequency range that characterizes the strongest reflection response of unstable particles to ultrasonic waves; the minimum particle size is the particle diameter value used to define the lower limit of the size of unstable particles; the maximum particle size is the particle diameter value used to define the upper limit of the size of unstable particles; and the characteristic particle size value is the characteristic diameter value used to represent the typical size of fine sand particles in the current instability phenomenon.

[0064] In specific implementation, firstly, the data processing unit extracts all characteristic frequency segments marked as abnormal frequency segments from the particle size attenuation spectrum of each cross-section where instability has been determined. For each abnormal frequency segment, the difference between the currently measured attenuation value and the preset mutation threshold is calculated, and this difference is the mutation amplitude of the frequency segment. The mutation amplitudes of all abnormal frequency segments are sorted from largest to smallest, and the characteristic frequency segment with the largest mutation amplitude is found. The frequency range corresponding to this characteristic frequency segment is taken as the main reflection frequency, and this main reflection frequency is marked as the frequency range in which the unstable particle generates the strongest ultrasonic wave reflection response. The characteristic frequency segment with the largest mutation amplitude is taken as the current mutation frequency segment, and the frequency range corresponding to this segment is taken as the main reflection frequency of the unstable particle. Then, the upper limit frequency value and lower limit frequency value of the current mutation frequency segment determined in step one are extracted. Utilizing the inverse relationship between ultrasonic frequency and particle size—higher frequencies correspond to smaller particle sizes, and lower frequencies to larger particle sizes—the upper frequency value is substituted into this inverse relationship to calculate the particle diameter corresponding to that upper frequency. This particle diameter is then used as the minimum particle size for the currently unstable particle. Similarly, the lower frequency value is substituted into the same inverse relationship to calculate the particle diameter corresponding to that lower frequency. This particle diameter is then used as the maximum particle size for the currently unstable particle. The minimum and maximum particle sizes together constitute the particle size range for the currently unstable particle. For example, assuming the current abrupt change frequency range is 200 kHz to 300 kHz, according to the inverse relationship, 300 kHz corresponds to a particle diameter of 0.1 mm, so the minimum particle size is 0.1 mm; 200 kHz corresponds to a particle diameter of 0.15 mm, so the maximum particle size is 0.15 mm. Finally, the arithmetic mean of the minimum and maximum particle sizes is calculated as the characteristic particle size value for the characteristic frequency range of the current abrupt change. This characteristic particle size value is output and used for parameter calculations in subsequent adjustment steps. The arithmetic mean of the minimum and maximum particle sizes is used as the characteristic particle size value.

[0065] In step 103, based on the characteristic particle size value, the upward flow resistance increment and the diameter of the hydrocyclone underflow outlet required to maintain boundary layer stability are adjusted in reverse gradient to obtain the particle size attenuation spectrum after each reverse gradient adjustment.

[0066] In some embodiments, the inverse gradient adjustment is performed on the increment of the upward flow resistance required to maintain boundary layer stability and the diameter of the hydrocyclone underflow outlet, based on the characteristic particle size value, with reference to... Figure 3 The figure is a flowchart illustrating the implementation of inverse gradient adjustment in some embodiments of this application. In this embodiment, inverse gradient adjustment can be implemented using the following steps:

[0067] In step 1031, the particle size range of the current unstable fine sand is determined according to the characteristic particle size value, and then the upward water flow resistance increment is adjusted according to the particle size range, and the diameter of the hydrocyclone bottom outlet is gradually increased according to the preset gradient step size.

[0068] In step 1032, the particle size attenuation spectrum is re-acquired after each adjustment. If the attenuation value of the unstable characteristic frequency band continues to decrease, the adjustment in the same direction continues.

[0069] In step 1033, if the attenuation value no longer decreases or worsens in the opposite direction, the adjustment amount of the previous step is reversed and the current diameter is locked, thus completing the reverse gradient adjustment of the upward water flow resistance increment and the diameter of the hydrocyclone underflow outlet.

[0070] It should be noted that, in this application, the stability of the graded boundary layer inside the hydrocyclone depends on the balance between the carrying capacity of the upward water flow for fine sand particles and the settling capacity of the fine sand particles themselves. When the fine sand becomes unstable due to floating, it indicates that the resistance of the upward water flow is too large relative to the current fine sand particle size range. It is necessary to increase the diameter of the underflow outlet to reduce the underflow resistance, so that more fluid can be discharged from the underflow, thereby reducing the carrying capacity of the upward water flow and allowing the fine sand particles to settle back into the underflow. The larger the characteristic particle size value, the coarser the unstable fine sand particles are, and a larger adjustment amount of the underflow outlet diameter is required to release the downward channel.

[0071] In practice, the data processing unit determines which of the three particle size classes (fine, medium, or extra-fine) the currently unstable fine sand belongs to based on the characteristic particle size value. Each class corresponds to a preset upward flow resistance increment step size; the larger the characteristic particle size value, the larger the selected resistance increment step size. According to the selected resistance increment step size, the control system sends a command to the electric adjustment mechanism installed at the underflow inlet of the hydrocyclone, causing the underflow inlet diameter to increase by one unit according to the preset gradient step size, for example, increasing by two millimeters each time. After completing one adjustment, the system waits for a preset stable operation time, usually thirty to sixty seconds, and then restarts the ultrasonic transceiver array to collect the particle size attenuation spectrum of each cross section and extract the instability characteristic frequency band. The current attenuation value is compared with the attenuation value before adjustment. If the current attenuation value is less than the attenuation value before adjustment and continues to decrease, it indicates that the adjustment direction is correct. Then, the underflow outlet diameter is increased again according to the same gradient step size, and the above acquisition and comparison process is repeated. If, after a certain adjustment, the attenuation value of the unstable characteristic frequency range no longer decreases, or the attenuation value is larger than before adjustment, it indicates that the adjustment is excessive or reverse deterioration has occurred. Then, the underflow outlet diameter is returned to the size before the last adjustment through the electric adjustment mechanism, and this size is locked as the optimal diameter under the current operating state. At the same time, an adjustment completion signal is sent to the control system. Thus, the reverse gradient adjustment of the upward water flow resistance increment and the underflow outlet diameter of the hydrocyclone is completed.

[0072] In step 104, when the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom, and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to the preset mutation threshold, the current underflow diameter remains unchanged until the next round of instability occurs.

[0073] It should be noted that, in this application, when the hydrocyclone is running normally and stably, the particles of different sizes in the sludge exhibit a natural distribution pattern of finer particles at the top and coarser particles at the bottom along the axial direction. This is reflected in the particle size attenuation spectrum as a layered distribution pattern that gradually decreases from the low cross section to the high cross section and from the low frequency band, and the attenuation value is gradually decreasing from top to bottom. Moreover, the attenuation value of each characteristic frequency band on each cross section is lower than the abrupt change threshold characterizing the instability boundary. This state indicates that the graded boundary layer has recovered stability and the fine sand no longer migrates to the overflow. At this time, there is no need to continue adjusting the underflow diameter. The current parameters should be locked to maintain stable operation until the next instability signal appears.

[0074] In practice, after each reverse gradient adjustment, the data processing unit re-acquires the particle size attenuation spectrum of each cross section. First, it checks whether the low-frequency attenuation value of the lowest cross section is the highest, whether the low-frequency attenuation value of the highest cross section is the lowest, and whether the low-frequency attenuation value between adjacent cross sections from the low to the high cross section shows a decreasing trend. If the above conditions are met, it is determined that the particle size attenuation spectrum has recovered to a layered distribution that increases from top to bottom. Then, it compares the current attenuation value of each characteristic frequency segment on each cross section with the preset mutation threshold. Only when the attenuation value of all characteristic frequency segments on all cross sections is less than or equal to the corresponding mutation threshold is it considered that all conditions are met. When the layered distribution condition and the full threshold condition are met simultaneously, the data processing unit sends a stable operation command to the control system. The control system stops sending any adjustment signals to the electric adjustment mechanism, locks the current underflow outlet diameter to a fixed value and keeps it unchanged. The system continues to monitor the ultrasonic echo information but does not trigger any adjustment action until the next round of instability is re-determined to have occurred, at which point the reverse gradient adjustment process is restarted.

[0075] Furthermore, in another aspect of this application, in some embodiments, this application provides an intelligent control system for wet treatment of sludge in drainage pipes and channels. This intelligent control system includes a control unit, as referenced... Figure 4 The figure is a schematic diagram of the structure of a control unit according to some embodiments of this application. The control unit includes: a monitoring module 201, a processing module 202, and an execution module 203, which are described below:

[0076] Monitoring module 201, in this application, is mainly used to monitor ultrasonic echo information in the cone section of the hydrocyclone, and then construct the particle size attenuation spectrum of sludge in the drainage pipe based on the ultrasonic echo information.

[0077] Processing module 202, in this application, is used to determine that the graded boundary layer is experiencing instability due to fine sand floating when the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than a preset abrupt change threshold and the corresponding attenuation direction is reverse propagating from the low cross section to the upper cross section, and then to determine the characteristic particle size value of the characteristic frequency band of the current abrupt change.

[0078] It should be noted that the processing module 202 is also used to perform reverse gradient adjustment on the upstream flow resistance increment and hydrocyclone underflow orifice diameter required to maintain boundary layer stability based on the characteristic particle size value, and to obtain the particle size attenuation spectrum after each reverse gradient adjustment.

[0079] The execution module 203 in this application is mainly used to maintain the current underflow diameter unchanged until the next round of instability occurs after the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to the preset mutation threshold.

[0080] The foregoing has detailed examples of intelligent control methods and systems for wet treatment of sludge in drainage pipes provided in this application. It is understood that the corresponding apparatus, in order to achieve the above functions, includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0081] In some embodiments, this application also provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device executes the above-described intelligent control method for wet treatment of sewage sludge in drainage pipes.

[0082] In some embodiments, reference Figure 5 The dashed lines in the figure indicate that the unit or module is optional. This figure is a structural schematic diagram of a computer device for implementing an intelligent control method for wet treatment of sludge in drainage pipes according to an embodiment of this application. The intelligent control method for wet treatment of sludge in drainage pipes described in the above embodiments can... Figure 5The computer device shown is used to implement this, and the computer device includes at least one processor 301, a memory 302 and at least one communication unit 305. The computer device may be a terminal device, a server or a chip.

[0083] Processor 301 can be a general-purpose processor or a special-purpose processor. For example, processor 301 can be a central processing unit (CPU), which can be used to control computer devices, execute software programs, and process data from software programs. The computer device may also include a communication unit 305 for inputting (receiving) and outputting (transmitting) signals.

[0084] For example, the computer device may be a chip, and the communication unit 305 may be the input and / or output circuit of the chip, or the communication unit 305 may be the communication interface of the chip, which may be a component of a terminal device, network device or other device.

[0085] For example, the computer device may be a terminal device or a server, and the communication unit 305 may be a transceiver of the terminal device or the server, or the communication unit 305 may be a transceiver circuit of the terminal device or the server.

[0086] The computer device may include one or more memories 302 storing a program 304. The program 304 can be executed by a processor 301 to generate instructions 303, causing the processor 301 to execute the method described in the above method embodiments according to the instructions 303. Optionally, the memory 302 may also store data (such as a target audit model). Optionally, the processor 301 may also read data stored in the memory 302, which may be stored at the same storage address as the program 304, or the data may be stored at a different storage address than the program 304.

[0087] The processor 301 and memory 302 can be configured separately or integrated together, for example, integrated on the system on chip (SOC) of the terminal device.

[0088] It should be understood that each step of the above method embodiment can be completed by hardware logic circuits or software instructions in the processor 301. The processor 301 can be a CPU, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, such as discrete gate, transistor logic devices, or discrete hardware components.

[0089] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0090] For example, in some embodiments, this application also provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to implement the above-described intelligent control method for wet treatment of sludge in drainage pipes and channels.

[0091] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0092] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An intelligent control method for wet treatment of sludge in drainage pipes and channels, used in the separation of fine sand (0.1 to 10 mm) during wet treatment of sludge in drainage pipes and channels, wherein a hydrocyclone identifies the floating instability phenomenon of fine sand in wet treatment by monitoring the ultrasonic particle size attenuation spectrum within its conical section, characterized in that... Includes the following steps: The ultrasonic echo information in the conical section of the hydrocyclone is monitored, and then the particle size attenuation spectrum of the sludge in the drainage pipe is constructed based on the ultrasonic echo information. When the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than the preset abrupt change threshold, and the corresponding attenuation direction is propagating countercurrently from the low cross section to the high cross section, it is determined that the graded boundary layer is experiencing an instability phenomenon of fine sand floating up, and then the characteristic particle size value of the characteristic frequency band of the current abrupt change is determined. Based on the characteristic particle size value, the upward flow resistance increment and the underflow diameter of the hydrocyclone required to maintain boundary layer stability are adjusted in reverse gradient to obtain the particle size attenuation spectrum after each reverse gradient adjustment. When the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom, and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to the preset mutation threshold, the current underflow diameter remains unchanged until the next round of instability occurs.

2. The method as described in claim 1, characterized in that, Ultrasonic transceiver arrays were used to monitor ultrasonic echo information in the conical section of a hydrocyclone.

3. The method as described in claim 1, characterized in that, The construction of the particle size attenuation spectrum of sewage sludge in drainage pipes based on the ultrasonic echo information specifically includes: The theoretical attenuation values ​​of ultrasound waves in clear water at different frequency bands are pre-calibrated to obtain a reference attenuation. Extract the echo attenuation of each cross section from the ultrasonic echo information; The echo attenuation of each cross section is compared with the reference attenuation of the corresponding frequency band to obtain the additional attenuation value caused by sludge particles in each frequency band. The particle size attenuation spectrum of the sludge in the drainage pipes was determined by using all additional attenuation values.

4. The method as described in claim 1, characterized in that, The instability phenomenon is the process by which fine sand particles in the graded boundary layer overcome the resistance of the upward water flow, migrate towards the overflow outlet, and cause fine sand loss, thus affecting the sand removal effect.

5. The method as described in claim 1, characterized in that, Determining the characteristic particle size value of the characteristic frequency range of the current mutation specifically includes: Identify the characteristic frequency segment with the largest abrupt change in attenuation value in the particle size attenuation spectrum, and obtain the principal reflection frequency of the unstable particle corresponding to the current abrupt change frequency segment; Based on the inverse relationship between ultrasonic frequency and particle size, the upper limit frequency of the abrupt frequency band is converted into the corresponding minimum particle size, and the lower limit frequency is converted into the corresponding maximum particle size. The characteristic particle size value of the characteristic frequency band of the current mutation is determined based on the minimum particle size and the maximum particle size.

6. The method as described in claim 1, characterized in that, The reverse gradient adjustment of the upward flow resistance increment and the underflow orifice diameter of the hydrocyclone based on the aforementioned characteristic particle size value specifically includes: The particle size range of the current unstable fine sand is determined based on the characteristic particle size value. Then, the gradient adjustment of the upward water flow resistance increment is performed based on the particle size range, and the diameter of the hydrocyclone bottom outlet is gradually increased according to the preset gradient step size. After each adjustment, the particle size attenuation spectrum is re-acquired. If the attenuation value in the unstable characteristic frequency range continues to decrease, the adjustment in the same direction is continued. If the attenuation value no longer decreases or worsens in the opposite direction, the adjustment amount of the previous step is reversed and the current diameter is locked, thus completing the reverse gradient adjustment of the upward water flow resistance increment and the diameter of the hydrocyclone underflow outlet.

7. The method as described in claim 1, characterized in that, The mutation threshold is the upper boundary value based on the statistical distribution of particle size attenuation spectrum under historical stable operating conditions.

8. An intelligent control system for wet treatment of sludge in drainage pipes and channels, the intelligent control system for wet treatment of sludge in drainage pipes and channels includes a control unit, characterized in that, The control unit includes: The monitoring module is used to monitor the ultrasonic echo information in the conical section of the hydrocyclone, and then construct the particle size attenuation spectrum of the sludge in the drainage pipe based on the ultrasonic echo information. The processing module is used to determine that the graded boundary layer is experiencing instability due to fine sand floating when the attenuation value of a characteristic frequency band in the particle size attenuation spectrum is greater than a preset abrupt change threshold and the corresponding attenuation direction is reverse propagating from the low cross section to the high cross section, and then to determine the characteristic particle size value of the characteristic frequency band of the current abrupt change. The processing module is also used to perform reverse gradient adjustment on the upstream flow resistance increment and hydrocyclone underflow orifice diameter required to maintain boundary layer stability based on the characteristic particle size value, and to obtain the particle size attenuation spectrum after each reverse gradient adjustment. The execution module is used to maintain the current underflow diameter unchanged until the next round of instability occurs after the particle size attenuation spectrum recovers to a layered distribution that increases from top to bottom and the attenuation value of each characteristic frequency band in the particle size attenuation spectrum is less than or equal to a preset mutation threshold.

9. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to call and run the computer programs from the memory, so that the computer device performs the intelligent control method for wet treatment of sewage sludge in drainage pipes as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions or code that, when executed on a computer, cause the computer to implement the intelligent control method for wet treatment of sludge in drainage pipes as described in any one of claims 1 to 7.

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