Method and control system for operating a two-phase centrifuge

Abstract

This invention relates to the field of centrifuge technology, specifically to a method and control system for operating a two-phase centrifuge. The control method includes: determining the solid phase inhomogeneity of the two-phase centrifuge at various times during the period from the current start to the present, when the initial slag discharge conditions are met; obtaining the reference degree of the historical slag discharge cycle to the current slag discharge cycle based on the solid phase inhomogeneity of the historical slag discharge cycle and its turbidity difference with that of the feed pipe during the current period; and determining the duration of the current slag discharge cycle based on the reference degree, the solid phase inhomogeneity of the current period, and the influence of the duration of the historical slag discharge cycle on the duration of the current period. This invention considers the different solid phase accumulation conditions in different regions inside the two-phase centrifuge when determining the duration of the current slag discharge cycle, thereby ensuring more accurate slag discharge timing and improving solid-liquid separation accuracy.

Description

Technical Field

[0001] This invention relates to the field of centrifuge technology, and specifically to a two-phase centrifuge operation control method and control system. Background Technology

[0002] Two-phase centrifuges, as highly efficient solid-liquid separation equipment, are widely used in various fields such as food, pharmaceuticals, chemicals, and environmental protection. They play an irreplaceable role, especially in processes such as treating high-concentration suspensions, extracting starch, recovering protein, and dewatering sludge. In recent years, with the improvement of industrial automation, higher requirements have been placed on the stability, separation efficiency, and intelligent control capabilities of centrifugal separation processes. In various continuous production or batch separation applications, the reliable operation and efficient separation effect of two-phase centrifuges directly affect product quality and production costs. Therefore, optimizing and intelligently upgrading their operation control has become one of the key areas of focus in the industry.

[0003] A common type of two-phase centrifuge is the disc centrifuge. During two-phase separation, disc centrifuges typically rely on a fixed discharge cycle or pressure changes in the chamber from a pressure sensor to determine the timing of discharge. However, in actual operation, this control method does not consider uneven solid phase distribution within the drum. For example, when the drum feeding system is blocked directionally or the feed rate is uneven, some areas may have insufficient solid phase accumulation, while others may have excessive accumulation. Even if the overall chamber pressure reaches the preset pressure threshold, some areas may not be completely discharged, while other areas may discharge excessive liquid phase. Inaccurate discharge timing leads to decreased solid-liquid separation accuracy and may even cause quality problems such as turbidity in the clear liquid. Summary of the Invention

[0004] To address the technical problem of inaccurate slag discharge timing during the operation and control of existing two-phase centrifuges, the present invention aims to provide a two-phase centrifuge operation and control method and system, the specific technical solution of which is as follows:

[0005] In a first aspect of the present invention, a method for controlling the operation of a two-phase centrifuge is provided, comprising:

[0006] When the initial slag discharge conditions are met, the solid phase inhomogeneity of the two-phase centrifuge at each moment during the period from the current start to the present is determined; the solid phase inhomogeneity characterizes the difference between the actual vibration time series data and the preset standard vibration time series data; the period from the current start to the present is the time period between the current moment and the start moment of the current slag discharge cycle;

[0007] Based on the solid phase inhomogeneity of historical slag discharge cycles and the turbidity difference between the feed pipes from the current start to the present, the reference degree of historical slag discharge cycles for the current slag discharge cycle is obtained.

[0008] Based on the aforementioned reference level, the solid phase inhomogeneity from the current start to the present, and the influence of the duration of historical slag discharge cycles on the duration of the current start to the present, the duration of the current slag discharge cycle is determined.

[0009] In an exemplary embodiment, the process of obtaining the solid phase inhomogeneity includes:

[0010] The time domain signal difference between the time domain signal of each frequency in the frequency domain signal of the actual vibration time series data at any given time moment and the time domain signal of the corresponding frequency in the frequency domain signal of the preset standard vibration time series data is obtained.

[0011] Based on the differences in time-domain signals at each frequency and the fluctuation degree of the corresponding time-domain signals in the frequency-domain signals of the actual vibration time-series data, the difference characteristics of each frequency are obtained; the difference characteristics are positively correlated with both the differences in time-domain signals and the fluctuation degree.

[0012] By integrating the differences in performance characteristics of each frequency and the degree of non-uniformity of each frequency, the solid phase non-uniformity at any given moment is obtained; the degree of non-uniformity characterizes the difference between each frequency and the rotational speed frequency of the two-phase centrifuge.

[0013] In an exemplary embodiment, the process of obtaining the degree of non-uniformity includes:

[0014] Obtain the frequency difference between each frequency and the rotational speed frequency of the two-phase centrifuge;

[0015] Determine the amplitude characteristics of each frequency in the frequency domain signal of the preset standard vibration time sequence data;

[0016] Based on the frequency differences and amplitude characteristics, the degree of non-uniformity at each frequency is obtained; the degree of non-uniformity is positively correlated with the frequency differences and negatively correlated with the amplitude characteristics.

[0017] In an exemplary embodiment, the process of fusing the difference characteristics of each frequency and the degree of inhomogeneity of each frequency to obtain the solid-phase inhomogeneity at any given time includes:

[0018] Based on the differences in performance characteristics at each frequency and the degree of non-uniformity at the corresponding frequency, the characteristics of the influence of solid-phase non-uniformity at each frequency are obtained.

[0019] The solid-phase inhomogeneity is obtained by integrating the solid-phase inhomogeneity influence characteristics of all frequencies.

[0020] In an exemplary embodiment, the process of obtaining the reference level includes:

[0021] The average solid phase inhomogeneity of the historical slag discharge cycle is obtained from the solid phase inhomogeneity at each moment within the historical slag discharge cycle.

[0022] Based on the mean value of solid phase inhomogeneity and the turbidity difference, the reference degree of the historical slag discharge cycle to the current slag discharge cycle is obtained; the reference degree is inversely correlated with both the mean value of solid phase inhomogeneity and the turbidity difference.

[0023] In an exemplary embodiment, the process of obtaining the duration of the current slag discharge cycle includes:

[0024] Determine the amount by which the duration of the historical slag discharge cycle exceeds the duration of the current period from its start to the present.

[0025] The initial duration adjustment amount is obtained by weighting the duration excess amount with a first adjustment coefficient; the first adjustment coefficient is obtained from the reference level.

[0026] The initial duration adjustment is weighted by a second adjustment coefficient to obtain the final duration adjustment; the second adjustment coefficient is obtained by the average value of the solid phase inhomogeneity at each moment in the period from the current start to the present.

[0027] The duration of the current slag discharge cycle is obtained by adjusting the duration of the current period from the beginning to the present based on the final duration adjustment amount.

[0028] In one exemplary embodiment, the two-phase centrifuge operation control method sets multiple historical slag discharge cycles;

[0029] The process of obtaining the initial duration adjustment includes:

[0030] The first adjustment coefficient for each historical slag discharge cycle is obtained based on the reference level of each historical slag discharge cycle, and the sum of the first adjustment coefficients of all historical slag discharge cycles is 1.

[0031] Based on the first adjustment coefficient of each historical slag discharge cycle, the time excess corresponding to each historical slag discharge cycle is weighted and summed to obtain the initial time adjustment amount.

[0032] In an exemplary embodiment, if the duration exceedance is less than 0, the duration exceedance is set to 0.

[0033] In an exemplary embodiment, after determining the duration of the current slag discharge cycle, the two-phase centrifuge operation control method further includes:

[0034] The turbidity increase trend at the liquid discharge port of a two-phase centrifuge at the monitoring time is obtained; the monitoring time is any time between the current time and the end time of the current slag discharge cycle.

[0035] If the increasing turbidity trend meets the preset conditions, the end time of the current slag discharge cycle will be updated to the monitoring time.

[0036] In a second aspect of the present invention, a two-phase centrifuge operation control system is provided, comprising: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-described two-phase centrifuge operation control method when the program instructions are executed.

[0037] This invention offers the following advantages: When initial slag discharge conditions are met, if some areas inside the two-phase centrifuge have insufficient solid phase accumulation while others have abundant solid phase accumulation, the vibration of the centrifuge will change significantly compared to normal operation. Therefore, based on the vibration differences, the solid phase non-uniformity of the two-phase centrifuge at various times within the current period is obtained. Combining this with the correlation between historical slag discharge cycles and the current period, the historical slag discharge cycle data is incorporated into the adjustment of the current slag discharge cycle duration, resulting in the current slag discharge cycle length. This invention considers the different solid phase accumulation conditions in different areas within the two-phase centrifuge when determining the current slag discharge cycle length, thereby ensuring more accurate slag discharge timing and improving solid-liquid separation accuracy. Attached Figure Description

[0038] Figure 1 This is a flowchart of a two-phase centrifuge operation control method provided in one embodiment of the present invention;

[0039] Figure 2 This is a flowchart of obtaining solid phase inhomogeneity according to an embodiment of the present invention;

[0040] Figure 3 This is a flowchart illustrating the process of obtaining the degree of non-uniformity according to an embodiment of the present invention;

[0041] Figure 4 This is a flowchart illustrating the process of obtaining a reference level according to an embodiment of the present invention;

[0042] Figure 5 This is a flowchart illustrating the process of obtaining the duration of the current slag discharge cycle, provided in one embodiment of the present invention. Detailed Implementation

[0043] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All data and information collected in this application have been obtained with full consent.

[0045] This embodiment provides a two-phase centrifuge operation control method for controlling the operation of a two-phase centrifuge, using a traditional disc centrifuge as an example. This embodiment provides a two-phase centrifuge operation control method that analyzes structural eccentricity or vibration abnormalities caused by uneven material stacking in the disc centrifuge drum during operation. It dynamically identifies solid phase inhomogeneity through vibration abnormalities and intelligently controls the slag discharge cycle based on historical slag discharge data. This achieves functional optimization of the traditional device with minimal modifications, improving the stability and separation effect of the separation process.

[0046] A disc centrifuge is equipped with a vibration sensor, a turbidity sensor, and a pressure sensor. The vibration sensor is mounted on the main shaft bearing housing of the disc centrifuge to accurately capture lateral vibration signals (i.e., vibration signals in a plane perpendicular to the axial direction) caused by material eccentricity. The vibration data is used to obtain real-time solid-phase inhomogeneity of the centrifuge drum. The vibration data acquired by the sensor is the real-time acceleration value. The sampling frequency of the vibration sensor is set according to actual needs, such as 5kHz.

[0047] The turbidity sensor consists of two units. The first is installed in the feed pipe of the disc centrifuge, and the second is installed at the liquid phase drain port, specifically in the drain pipe of the supernatant (liquid phase) after centrifugation. The first turbidity sensor is used to acquire the turbidity in the feed pipe, i.e., the turbidity of the initial suspension before separation. The second turbidity sensor is used to acquire the turbidity of the liquid phase after centrifugation. The unit of turbidity is NTU, and the sampling frequency of the turbidity sensor is set according to actual needs, such as 10Hz.

[0048] The pressure sensor is installed inside the disc centrifuge, specifically at the pressure conduit interface connecting the top of the centrifuge chamber to the internal working chamber. It is located at the top of the disc stack or near the gas-liquid boundary, and is used to monitor the gas compression within the chamber during the solid-phase accumulation process caused by rotation. The pressure sensor can collect the instantaneous pressure value inside the chamber in real time. The sampling frequency can be set according to actual needs, such as 100Hz. It should be understood that the pressure data detected by the pressure sensor is the data required for determining the start-up of the disc centrifuge's slag discharge.

[0049] Each sensor connects to the control device, either wired or wirelessly. If a wireless connection is used, each sensor needs to be equipped with a high-density micro battery, such as a button cell battery, to ensure long-term power supply.

[0050] Each sensor acquires data information during the operation of the disc centrifuge. The control device acquires the data information collected by each sensor and processes the data to execute the two-phase centrifuge operation control method provided in this embodiment.

[0051] like Figure 1 As shown, the two-phase centrifuge operation control method provided in this embodiment includes the following steps:

[0052] Step S1: Under the condition of initial slag discharge, determine the solid phase inhomogeneity of the two-phase centrifuge at each moment from the current start to the present.

[0053] Step S2: Based on the solid phase inhomogeneity of the historical slag discharge cycle and the turbidity difference of the feed pipe from the current start to the present, the reference degree of the historical slag discharge cycle to the current slag discharge cycle is obtained.

[0054] Step S3: Based on the reference level, the solid phase inhomogeneity from the current start to the present, and the influence of the duration of historical slag discharge cycles on the duration of the current start to the present, determine the duration of the current slag discharge cycle.

[0055] The following detailed explanation of each step, in conjunction with the accompanying drawings, is provided.

[0056] Step S1: When the initial slag discharge conditions are met, determine the solid phase inhomogeneity of the two-phase centrifuge at each moment during the period from the current start to the present.

[0057] The existing slag discharge start-up mechanism for disc centrifuges is as follows: during the operation of the disc centrifuge, the system determines whether a slag discharge operation is needed based on the detected pressure; that is, slag discharge is initiated when the pressure reaches a preset pressure threshold. Therefore, the initial slag discharge condition for a disc centrifuge is whether the pressure reaches the preset pressure threshold. Meeting the initial slag discharge condition means that the pressure reaches the preset pressure threshold.

[0058] However, the existing slag discharge start-up mechanism does not consider the uneven distribution of solid phase inside the drum. When the uneven distribution of solid phase inside the drum is severe, the accuracy of slag discharge using the traditional pressure detection method will decrease. When the solid phase accumulates in a certain radial direction, causing internal inhomogeneity, there are two situations: First, the solid phase accumulation area is not located in the pressure sensing area. In this case, the pressure rise rate is slower than normal. However, to ensure that there is no liquid phase mixing in the solid phase separation result, slag discharge can still be initiated based on whether the pressure reaches the preset pressure threshold. Second, when the solid phase accumulation area is located in the pressure sensing area, the pressure rise rate is faster, but the solid phase accumulation in other areas is insufficient. If slag discharge is still initiated using the traditional pressure detection method, it will lead to premature slag discharge from areas with insufficient solid phase accumulation, exacerbating liquid phase mixing during the slag discharge process. Therefore, after meeting the initial slag discharge conditions, it is also necessary to determine the duration of the current slag discharge cycle using the two-phase centrifuge operation control method provided in this embodiment.

[0059] During the operation of a disc centrifuge, the solid phase experiences significant centrifugal force as the drum rotates. Because the solid phase is denser than the liquid phase, it tends to accumulate at the solid outlet during centrifugation. If the solid phase is evenly distributed inside the drum, the rotation process will be in dynamic equilibrium, with minimal vibration along the plane perpendicular to the axial direction. The only vibrations present are those caused by motor rotation or the natural frequency of the structure. However, as the separation process progresses, some solid phase accumulates in the middle of the discs, leading to an uneven distribution of the solid phase along the circumferential direction of rotation. At this point, the mass distribution inside the drum is no longer symmetrical, and the vibration data will be affected by the solid phase distribution, resulting in significant differences from normal vibration data.

[0060] The disc centrifuge is set with a slag discharge cycle, which is the time interval between two adjacent slag discharge actions, that is, the time interval between the end time of the previous slag discharge and the start time of the current slag discharge.

[0061] This embodiment is used to determine the duration of the current slag discharge cycle so that slag discharge can be initiated when the duration of the current slag discharge cycle arrives. It should be understood that the end time of the current slag discharge cycle, i.e., the time of the next slag discharge start, is a future time relative to the current time; therefore, the current time is within the current slag discharge cycle. The current time is the time when the initial slag discharge conditions are met. This embodiment defines a parameter, the period from the current start time to the present time, which refers to the time period between the current time and the start time of the current slag discharge cycle. Therefore, the period from the current start time to the present time is the time period already elapsed within the current slag discharge cycle.

[0062] The solid phase inhomogeneity of the disc centrifuge at each moment during the current period is determined. Solid phase inhomogeneity characterizes the difference between the actual vibration time-series data and the preset standard vibration time-series data at each moment; the greater the difference, the stronger the solid phase inhomogeneity. The preset standard vibration time-series data can be the normal vibration data of the disc centrifuge under conditions without solid phase interference. In an exemplary embodiment, before the disc centrifuge performs normal separation, pure liquid is added to the disc centrifuge, allowing it to operate in a pure liquid state, thereby acquiring vibration data during operation as the preset standard vibration time-series data. Furthermore, the liquid added to the disc centrifuge can be of the same type as the liquid in the separated suspension to improve the accuracy and reliability of data processing.

[0063] In one exemplary embodiment, such as Figure 2 As shown, the following is a specific process for obtaining solid-phase inhomogeneity:

[0064] Step S11: Obtain the time domain signal difference between the time domain signal of each frequency in the frequency domain signal of the actual vibration time series data corresponding to any time moment and the time domain signal of the corresponding frequency in the frequency domain signal of the preset standard vibration time series data.

[0065] For ease of explanation, any point in the time period from the current start date is defined as the target time. A reference time period is then determined, which is a preset length of time with the target time as its end point. That is, the last moment of the reference time period is the target time. The length of the reference time period is set according to actual needs, such as including 10 moments. Since vibration data is acquired once at each moment, the actual vibration time series data for the reference time period is constructed based on the vibration data at each moment within the reference time period, and this data serves as the actual vibration time series data for the target time period. It should be understood that, for ease of comparison, the preset standard vibration time series data is the same length as the reference time period.

[0066] The actual vibration time-series data at the target time and the preset standard vibration time-series data are converted to the frequency domain using a traditional Fast Fourier Transform. It should be understood that for the frequency domain space of the preset standard vibration time-series data, when the material distribution inside the disc centrifuge is uniform, the main frequency in its frequency domain space is the frequency of the drum rotation, defined as the rotational frequency, also known as the rotational speed frequency.

[0067] Determine each frequency in the frequency domain signal of the actual vibration time-series data at the target time. For any given frequency, obtain the time domain signal of that frequency in the frequency domain signal of the actual vibration time-series data. Specifically, set the amplitude of all other frequencies in the frequency domain signal of the actual vibration time-series data to 0 to filter out all other frequencies. Then, perform an inverse Fourier transform on the component of that frequency in the frequency domain signal of the actual vibration time-series data to obtain the time domain signal of that frequency in the frequency domain signal of the actual vibration time-series data. Similarly, obtain the time domain signals of each frequency in the frequency domain signal of the actual vibration time-series data. Furthermore, similarly, obtain the time domain signals of each frequency in the frequency domain signal of the preset standard vibration time-series data. It should be understood that the center frequency of the frequency domain signal of the preset standard vibration time-series data is used as the rotational speed frequency of the disc centrifuge.

[0068] For any given frequency, the time-domain signal difference between the actual vibration time-series data at the target time and the time-domain signal of the same frequency in the frequency-domain data of the preset standard vibration time-series data is obtained. Specifically, the time-domain signal difference is the DTW (Dynamic Time Warping) distance between the two. A larger DTW distance indicates that the responses of the actual vibration time-series data and the preset standard vibration time-series data at that frequency are less similar over time, the actual vibration of the disc centrifuge at the target time is less similar to the vibration in a pure liquid state, the greater the time-domain signal difference, and the more non-uniform the solid phase inside the disc centrifuge at the target time, thus having a greater impact on the vibration. Similarly, the time-domain signal difference between the time-domain signals of each frequency in the frequency-domain data of the actual vibration time-series data at the target time and the corresponding frequency in the frequency-domain data of the preset standard vibration time-series data is obtained.

[0069] Step S12: Based on the differences in the time domain signals of each frequency and the fluctuation degree of the time domain signal of the corresponding frequency in the frequency domain signal of the actual vibration time series data, the difference characteristics of each frequency are obtained.

[0070] For any given frequency, the fluctuation degree of the time-domain signal at that frequency in the frequency domain signal of the actual vibration time-series data is obtained. In this embodiment, the fluctuation degree is represented by the standard deviation, that is, the standard deviation of the time-domain signal at that frequency in the frequency domain signal of the vibration time-series data is calculated. In this way, the standard deviation of the time-domain signal of each frequency in the frequency domain signal of the actual vibration time-series data is obtained.

[0071] The greater the difference in the time-domain signals at each frequency, the greater the difference between the time-domain signals at each frequency and the standard, and the more obvious the difference characteristics at each frequency; the two are positively correlated. The greater the standard deviation of the time-domain signals at each frequency, the stronger the fluctuation of the time-domain signals at each frequency, and the more obvious the difference characteristics at each frequency; the two are also positively correlated. Therefore, based on the differences in the time-domain signals at each frequency and the degree of fluctuation of the corresponding frequency's time-domain signal in the frequency domain signal of the actual vibration time-series data, the difference characteristics at each frequency are obtained. In an exemplary embodiment, a specific quantification method for the difference characteristics is given below:

[0072] ;

[0073] in, Indicates the first The moment of the first The characteristics of differences in each frequency Indicates the first In the frequency domain signal of the actual vibration time sequence data at time n, the first... A time-domain signal of a frequency. Indicates the first Actual vibration time series data at each moment The frequency domain signal representing the preset standard vibration time sequence data. A time-domain signal of a frequency. This represents the preset standard vibration time sequence data. express and DTW distance, express The standard deviation. This represents a normalization function, such as the tanh function.

[0074] Step S13: Combine the differences in performance characteristics of each frequency and the degree of non-uniformity of each frequency to obtain the solid phase non-uniformity at any given time.

[0075] First, the degree of non-uniformity at each frequency is determined. The degree of non-uniformity characterizes the difference between each frequency and the rotational speed frequency of the disc centrifuge; the greater the difference, the stronger the non-uniformity. In an exemplary embodiment, such as... Figure 3 As shown, the following is a specific process for obtaining the degree of unevenness:

[0076] Step S131: Obtain the frequency difference between each frequency and the rotational speed frequency of the two-phase centrifuge.

[0077] For any given frequency, the frequency difference between that frequency and the rotational speed frequency of the disc centrifuge is obtained. In an exemplary embodiment, the frequency difference is specifically the absolute value of the difference between the given frequency and the rotational speed frequency of the disc centrifuge. The larger the frequency difference, the greater the difference between the given frequency and the rotational speed frequency, and the stronger the degree of frequency non-uniformity; therefore, the two are positively correlated. Similarly, the frequency difference between each frequency and the rotational speed frequency of the disc centrifuge is obtained.

[0078] Step S132: Determine the amplitude characteristics of each frequency in the frequency domain signal of the preset standard vibration time sequence data.

[0079] For any given frequency, the amplitude characteristics of that frequency in the frequency domain signal of the preset standard vibration time series data are obtained. In an exemplary embodiment, the amplitude characteristic is specifically the average amplitude of that frequency in the frequency domain signal of the preset standard vibration time series data. The larger the average amplitude of the frequency, the more prominent the frequency is in the frequency domain signal of the preset standard vibration time series data, the greater the frequency's response, and the lower the degree of non-uniformity of the frequency; therefore, the two are inversely correlated. Similarly, the amplitude characteristics of each frequency in the frequency domain signal of the preset standard vibration time series data are obtained.

[0080] Step S133: Based on the frequency differences and amplitude characteristics, obtain the degree of non-uniformity of each frequency.

[0081] Based on the frequency differences and amplitude characteristics corresponding to each frequency, the degree of non-uniformity at each frequency is obtained. In an exemplary embodiment, a specific quantification method for the degree of non-uniformity is given below:

[0082] ;

[0083] in, Indicates the first The degree of unevenness in frequency response, Indicates the first The frequency magnitude of each frequency, Indicates rotational speed and frequency. Indicates the first The average amplitude of each frequency in the frequency domain signal of the preset standard vibration time series data. This represents an exponential function with the natural constant as its base.

[0084] Then, by fusing the difference characteristics of each frequency and the degree of inhomogeneity at each frequency, the solid-phase inhomogeneity at the target time is obtained. The stronger the difference characteristics, the stronger the solid-phase inhomogeneity at the target time; the stronger the degree of inhomogeneity, the stronger the solid-phase inhomogeneity at the target time. Based on the above logical relationship, firstly, according to the difference characteristics of each frequency and the corresponding degree of inhomogeneity, the solid-phase inhomogeneity influence characteristics of each frequency are obtained. Then, the solid-phase inhomogeneity influence characteristics of all frequencies are fused to obtain the solid-phase inhomogeneity. In an exemplary embodiment, a specific quantification method for solid-phase inhomogeneity is given below:

[0085] ;

[0086] in, Indicates the first Solid-phase inhomogeneity at a given time, Indicates the total number of frequencies. Indicates the first The influence characteristics of solid-phase inhomogeneity at each frequency.

[0087] Using the above method, the solid phase inhomogeneity at each moment in the period from the current start to the present can be obtained.

[0088] By analyzing the vibration under standard conditions, i.e., the vibration data under full liquid conditions (i.e., without considering solid phase inhomogeneity), and comparing it with the vibration data under actual operating conditions, we can obtain real-time vibration anomalies, i.e., real-time solid phase inhomogeneity, and then conduct further analysis.

[0089] Step S2: Based on the solid phase inhomogeneity of the historical slag discharge cycle and the turbidity difference of the feed pipe from the current start to the present, the reference degree of the historical slag discharge cycle to the current slag discharge cycle is obtained.

[0090] This embodiment sets a historical slag discharge cycle. It should be understood that the historical slag discharge cycle is the slag discharge cycle before the current slag discharge cycle. The number of historical slag discharge cycles can be one or more.

[0091] Based on historical slag discharge cycle data and the turbidity difference in the feed pipe between the current start and present periods, the reference level of the historical slag discharge cycle for the current slag discharge cycle is determined, thereby determining the duration of the current slag discharge cycle. In an exemplary embodiment, such as... Figure 4 As shown, the following is a specific process for obtaining the reference level:

[0092] Step S21: Obtain the average value of solid phase inhomogeneity for the historical slag discharge cycle from the solid phase inhomogeneity at each moment within the historical slag discharge cycle.

[0093] The solid phase inhomogeneity acquisition process in step S1 is applied to each moment within the historical slag discharge cycle to obtain the solid phase inhomogeneity at each moment within the historical slag discharge cycle. Then, the average value of the solid phase inhomogeneity at each moment within the historical slag discharge cycle is calculated as the average value of the solid phase inhomogeneity for the historical slag discharge cycle.

[0094] If multiple historical slag discharge cycles are set, the solid phase inhomogeneity at each moment within each historical slag discharge cycle is obtained. Then, for each historical slag discharge cycle, the average value of the solid phase inhomogeneity at each moment within the historical slag discharge cycle is calculated, thereby obtaining the average solid phase inhomogeneity value for each historical slag discharge cycle.

[0095] Step S22: Based on the average solid phase inhomogeneity and turbidity differences, determine the reference level of the historical slag discharge cycle for the current slag discharge cycle.

[0096] There are differences in the turbidity of the suspension in the feed pipe during different historical slag discharge cycles, that is, there are differences in the solid content of the suspension. Based on different turbidities, the corresponding duration of the slag discharge cycle also varies. Therefore, the turbidity difference of the feed pipe between the historical slag discharge cycle and the current period is first determined.

[0097] For any given historical slag discharge cycle, the turbidity of the feed pipe at each moment within that cycle is obtained. The average turbidity of the feed pipe at each moment within that historical slag discharge cycle is then calculated, and this result is taken as the turbidity of that historical slag discharge cycle. Similarly, the turbidity of the feed pipe at each moment within the current period is obtained, and the average turbidity of the feed pipe at each moment within the current period is calculated, and this result is taken as the turbidity of the current period. Then, the absolute value of the difference between the turbidity of the historical slag discharge cycle and the turbidity of the current period is calculated, and this difference is taken as the turbidity difference between the historical slag discharge cycle and the current period. The greater the turbidity difference, the larger the difference between the historical and current slag discharge cycles in terms of the turbidity of the suspension in the feed pipe. Therefore, when determining the duration of the current slag discharge cycle, the weaker the reference value of the historical slag discharge cycle is to the current slag discharge cycle. Thus, the reference value is inversely correlated with the turbidity difference.

[0098] The greater the mean solid phase inhomogeneity of the historical slag discharge cycle, the more abnormal the solid phase condition is within that historical slag discharge cycle. When determining the duration of the current slag discharge cycle, in order to avoid affecting the duration of the current slag discharge cycle, the reference degree of the historical slag discharge cycle to the current slag discharge cycle is weaker. Therefore, the reference degree is inversely correlated with the mean solid phase inhomogeneity of the historical slag discharge cycle.

[0099] Therefore, for any historical slag discharge cycle, the reference level of that historical slag discharge cycle to the current slag discharge cycle can be obtained based on the average solid phase inhomogeneity of that historical slag discharge cycle and the difference in turbidity between that historical slag discharge cycle and the period from the current start to the present. Based on the above logic, a specific quantification method for the reference level is given below:

[0100] ;

[0101] in, Indicates the first How relevant are historical slag discharge cycles to the current slag discharge cycle? Indicates the first The average solid phase inhomogeneity over a historical slag discharge cycle. Indicates the first Turbidity of a historical slag discharge cycle This indicates the turbidity from the beginning of the current period to the present.

[0102] By using the above process, the reference degree of each historical slag discharge cycle to the current slag discharge cycle can be obtained.

[0103] Step S3: Based on the reference level, the solid phase inhomogeneity from the current start to the present, and the influence of the duration of historical slag discharge cycles on the duration of the current start to the present, determine the duration of the current slag discharge cycle.

[0104] First, calculate the average solid-phase inhomogeneity at each moment during the period from the current start to the present, and use this average as the solid-phase inhomogeneity for the period from the current start to the present.

[0105] Then, based on the reference level of each historical slag discharge cycle to the current slag discharge cycle, the solid phase inhomogeneity from the current start to the present, and the influence of the duration of each historical slag discharge cycle on the duration of the current start to the present, the duration of the current slag discharge cycle is determined. In an exemplary embodiment, such as Figure 5 As shown, the following is a specific process for obtaining the duration of the current slag removal cycle:

[0106] Step S31: Determine the amount by which the duration of the historical slag discharge cycle exceeds the duration of the period from the current start to the present.

[0107] For any historical slag discharge cycle, determine the duration of that historical slag discharge cycle and the duration of the period from the current start date. Calculate the duration excess of the historical slag discharge cycle relative to the duration of the period from the current start date; this excess is calculated by subtracting the duration of the historical slag discharge cycle from the duration of the period from the current start date. If the excess is less than 0, it is set to 0. Therefore, the value of the excess is limited to being greater than or equal to 0.

[0108] Step S32: Weight the duration excess by the first adjustment coefficient to obtain the initial duration adjustment amount.

[0109] Based on the reference level of historical slag discharge cycles, the first adjustment coefficient of the historical slag discharge cycle is obtained. In the case of multiple historical slag discharge cycles, the sum of the reference levels of all historical slag discharge cycles is calculated as the reference level sum. Then, the ratio of the reference level of each historical slag discharge cycle to the reference level sum is calculated, and the result is the first adjustment coefficient of each historical slag discharge cycle, thus ensuring that the sum of the first adjustment coefficients of all historical slag discharge cycles is 1.

[0110] Then, based on the first adjustment coefficient of each historical slag discharge cycle, the time excess corresponding to each historical slag discharge cycle is weighted and summed to obtain the initial time adjustment amount. The calculation formula is as follows:

[0111] ;

[0112] in, This indicates the initial duration adjustment amount. Indicates the first The first adjustment coefficient for each historical slag discharge cycle This indicates the number of historical slag discharge cycles. express Functions used to convert Limited to being greater than or equal to 0, Indicates the first The duration of a historical slag discharge cycle, This indicates the duration of the period from the current start date to the present. Indicates the first The duration of a historical slag discharge cycle exceeds the duration of the period from the current start to the present.

[0113] Step S33: Weight the initial duration adjustment amount using the second adjustment coefficient to obtain the final duration adjustment amount.

[0114] The second adjustment coefficient is obtained by averaging the solid-phase inhomogeneity at each moment during the period from the current start to the present. In an exemplary embodiment, the average solid-phase inhomogeneity at each moment during the period from the current start to the present is directly used as the second adjustment coefficient. The second adjustment coefficient is multiplied by the initial duration adjustment amount, and the product is used as the final duration adjustment amount.

[0115] Step S34: Adjust the duration of the period from the current start to the present according to the final duration adjustment amount to obtain the duration of the current slag discharge cycle.

[0116] The final duration adjustment is added to the duration of the period from the current start to the present, and the sum is the duration of the current slag discharge cycle.

[0117] During the above process, if there are a large number of historical slag discharge cycles with a duration exceeding 0, it indicates that the period from the current start to the present is shorter compared to the previous normal slag discharge cycle. This means that if slag discharge is initiated at the current moment, it may be premature. Furthermore, if the solid phase inhomogeneity from the current start to the present is significant, it indicates that there is uneven solid phase distribution within this period, and solid phase has accumulated in the pressure detection area. Therefore, even if the pressure reaches the preset pressure threshold, the slag discharge cycle will be further extended based on the duration of the current start to the present period to ensure that slag is not discharged prematurely and that excessive liquid phase is not discharged during slag discharge, thus preventing solid-liquid mixing.

[0118] When the number of historical slag discharge cycles with a duration greater than 0 is small, and the solid phase inhomogeneity from the current start to the present is small, the increase in duration from the current start to the present is also small.

[0119] Slag discharge control is performed based on the duration of the current slag discharge cycle. For example, the end time of the current slag discharge cycle is obtained based on the duration of the current slag discharge cycle and the start time of the current slag discharge cycle. Then, control is performed based on the time interval between the current time and the end time, and slag discharge is started when the end time arrives.

[0120] Furthermore, when controlling slag discharge based on the current slag discharge cycle length, there is a possibility that the cycle length may be too long. For example, if the solid phase accumulation area is not located within the pressure sensing area, it is impossible to directly determine the solid phase accumulation at other locations. As solid phase accumulation increases, it may cause confusion between the solid phase and the liquid phase at the outlet, leading to an increase in turbidity during liquid phase discharge. Therefore, after determining the current slag discharge cycle length, it is also necessary to control slag discharge promptly based on the increasing turbidity trend at the liquid phase discharge port.

[0121] For ease of explanation, the monitoring time is set to any time between the current time and the end time of the current slag discharge cycle. Of course, the monitoring time can also be the current time or the end time of the current slag discharge cycle.

[0122] The turbidity increase trend at the liquid discharge port of a disc centrifuge at the monitoring time is obtained. The process of obtaining the turbidity increase trend at the monitoring time can be as follows: determine the turbidity of the liquid discharge port at each time within a reference period of the monitoring time; construct a turbidity sequence from the turbidity of the liquid discharge port at each time within the reference period, using this as the turbidity sequence for the monitoring time; and then obtain the turbidity increase trend based on the turbidity sequence. In an exemplary embodiment, a linear fit is performed on the turbidity sequence to obtain the slope of the fitted line. A slope greater than 0 indicates an increasing turbidity trend, and the larger the slope value, the more obvious the increasing turbidity trend; a slope less than 0 indicates a decreasing turbidity trend, and the smaller the slope value, the more obvious the decreasing turbidity trend; a slope equal to 0 indicates a stable turbidity state. The turbidity increase trend is then obtained based on the slope value. Alternatively, the slope value can be directly used as the turbidity increase trend, or the slope can be normalized using a sigmoid function, with the normalized result representing the turbidity increase trend.

[0123] If the turbidity increase trend meets the preset conditions, then to prevent further increase in turbidity, the current slag discharge cycle will not be extended. Instead, the end time of the current slag discharge cycle will be updated to the monitoring time, thereby controlling the immediate initiation of slag discharge. In an exemplary embodiment, a turbidity increase trend threshold is preset. This preset turbidity increase trend threshold is set according to actual judgment needs. For example, based on the turbidity increase trend being the result of the slope being normalized by the sigmoid function, the preset turbidity increase trend threshold can be set to a value slightly greater than 0.5 (the overall value range of the preset turbidity increase trend threshold is 0.5-1), such as 0.6. This ensures that when the turbidity has a certain increasing trend, the end time of the current slag discharge cycle will be updated to the monitoring time.

[0124] Using the above method, as time progresses, every moment between the current moment and the end moment of the current slag discharge cycle is iterated in turn until the above conditions are met, or until the end moment of the current slag discharge cycle arrives.

[0125] In addition, if the solid phase inhomogeneity is large in several consecutive slag discharge cycles, such as when the solid phase inhomogeneity exceeds the preset threshold for more than 5 consecutive slag discharge cycles, it is determined that there is an abnormality inside the centrifuge. At this time, an abnormal operation warning signal is output, a shutdown signal is output or a manual maintenance is prompted to prevent problems such as decreased slag discharge efficiency, abnormal increase in turbidity of the effluent, or equipment damage during continuous operation.

[0126] This embodiment also provides a two-phase centrifuge operation control system, including: a memory and a processor; the memory is connected to the processor, and the memory is used to store program instructions; the processor is used to implement the steps in the above-described two-phase centrifuge operation control method embodiment when the program instructions are executed.

[0127] In one exemplary embodiment, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the embodiments of the two-phase centrifuge operation control method.

[0128] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0129] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for controlling the operation of a two-phase centrifuge, characterized in that, include: Under the condition of initial slag discharge, determine the solid phase inhomogeneity of the two-phase centrifuge at each moment from the current start to the present. The solid phase inhomogeneity characterizes the difference between the actual vibration time series data and the preset standard vibration time series data; the current start to present time period is the time period between the current moment and the start moment of the current slag discharge cycle; Based on the solid phase inhomogeneity of historical slag discharge cycles and the turbidity difference between the feed pipes from the current start to the present, the reference degree of historical slag discharge cycles for the current slag discharge cycle is obtained. Based on the aforementioned reference level, the solid phase inhomogeneity from the current start to the present, and the influence of the duration of historical slag discharge cycles on the duration of the current start to the present, the duration of the current slag discharge cycle is determined. The process of obtaining solid-phase inhomogeneity includes: obtaining the time-domain signal difference between the time-domain signals of each frequency in the frequency-domain signal of the actual vibration time-series data at any given time and the time-domain signal of the corresponding frequency in the frequency-domain signal of the preset standard vibration time-series data; obtaining the difference characteristics of each frequency based on the time-domain signal differences of each frequency and the fluctuation degree of the time-domain signal of the corresponding frequency in the frequency-domain signal of the actual vibration time-series data; the difference characteristics are positively correlated with both the time-domain signal differences and the fluctuation degree; and fusing the difference characteristics of each frequency and the degree of inhomogeneity of each frequency to obtain the solid-phase inhomogeneity at any given time; the degree of inhomogeneity characterizes the difference between each frequency and the rotational speed frequency of the two-phase centrifuge. The process of obtaining the degree of non-uniformity includes: obtaining the frequency difference between each frequency and the rotational speed frequency of the two-phase centrifuge; determining the amplitude characteristics of each frequency in the frequency domain signal of the preset standard vibration time sequence data; obtaining the degree of non-uniformity of each frequency based on the frequency difference and amplitude characteristics; the degree of non-uniformity is positively correlated with the frequency difference and negatively correlated with the amplitude characteristics. The process of obtaining the reference level includes: obtaining the average solid phase inhomogeneity of the historical slag discharge cycle from the solid phase inhomogeneity at each moment within the historical slag discharge cycle; obtaining the reference level of the historical slag discharge cycle to the current slag discharge cycle based on the average solid phase inhomogeneity and the turbidity difference; the reference level is inversely correlated with both the average solid phase inhomogeneity and the turbidity difference. The process of obtaining the duration of the current slag discharge cycle includes: determining the duration excess of the historical slag discharge cycle relative to the duration of the period from the current start to the present; weighting the duration excess with a first adjustment coefficient to obtain an initial duration adjustment; the first adjustment coefficient being obtained from the reference level; weighting the initial duration adjustment with a second adjustment coefficient to obtain a final duration adjustment; the second adjustment coefficient being obtained from the average solid phase inhomogeneity at each moment in the period from the current start to the present; and adjusting the duration of the period from the current start to the present based on the final duration adjustment to obtain the duration of the current slag discharge cycle.

2. The two-phase centrifuge operation control method as described in claim 1, characterized in that, The solid-phase inhomogeneity at any given time is obtained by fusing the difference characteristics of each frequency and the degree of inhomogeneity at each frequency, including: Based on the differences in performance characteristics at each frequency and the degree of non-uniformity at the corresponding frequency, the characteristics of the influence of solid-phase non-uniformity at each frequency are obtained. The solid-phase inhomogeneity is obtained by integrating the solid-phase inhomogeneity influence characteristics of all frequencies.

3. The two-phase centrifuge operation control method as described in claim 1, characterized in that, The two-phase centrifuge operation control method sets multiple historical slag discharge cycles; The process of obtaining the initial duration adjustment includes: The first adjustment coefficient for each historical slag discharge cycle is obtained based on the reference level of each historical slag discharge cycle, and the sum of the first adjustment coefficients of all historical slag discharge cycles is 1. Based on the first adjustment coefficient of each historical slag discharge cycle, the time excess corresponding to each historical slag discharge cycle is weighted and summed to obtain the initial time adjustment amount.

4. The two-phase centrifuge operation control method as described in claim 1, characterized in that, If the duration exceedance is less than 0, then the duration exceedance is set to 0.

5. The two-phase centrifuge operation control method as described in claim 1, characterized in that, After determining the duration of the current slag discharge cycle, the two-phase centrifuge operation control method further includes: The turbidity increase trend at the liquid discharge port of a two-phase centrifuge at the monitoring time is obtained; the monitoring time is any time between the current time and the end time of the current slag discharge cycle. If the increasing turbidity trend meets the preset conditions, the end time of the current slag discharge cycle will be updated to the monitoring time.

6. A two-phase centrifuge operation control system, characterized in that it includes: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is configured to implement the two-phase centrifuge operation control method according to any one of claims 1-5 when program instructions are executed.

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