A method for co2 antifoam control in beer production

Abstract

The application relates to the field of industrial automation control, and particularly discloses a CO2 defoaming control method for beer production, which comprises the following steps: synchronously collecting defoaming probe and control valve level signals, extracting compression response time and rebound recovery time, and performing dynamic double-time analysis to generate a dynamic descriptor; constructing a compression and rebound response trend sequence of a historical defoaming period based on a sliding time window, and identifying a foam elimination effect; combining adjacent control valve opening intervals and state factors to determine whether high-frequency false touch oscillation is caused, and recording oscillation depth; according to the oscillation depth and an expected defoaming shortest time, forcibly extending CO2 injection and shielding a conventional valve closing logic, implementing forced defoaming action, and judging whether the high-frequency false touch oscillation is eliminated according to a state factor of a subsequent period; and the application quantifies the pseudo-foam elimination degree of foam elastic compression and adapts to forced defoaming, effectively eliminates high-frequency false touch oscillation, and improves the actual defoaming effect.

Description

Technical Field

[0001] This invention relates to the field of industrial automation control, and specifically to a CO2 defoaming control method for beer production. Background Technology

[0002] In high-density fermentation processes such as beer brewing, traditional CO2 defoaming control systems rely on conductivity or capacitance probes to detect foam height and break up the foam by controlling the opening and closing of valves to control the CO2 airflow.

[0003] However, existing technical solutions have an overlooked flaw: when CO2 gas flow impacts the foam layer, the CO2 flow may cause elastic compression of the foam layer instead of substantial rupture. Due to the elastic compression, the defoaming probe misjudges that the foam has been eliminated, triggering the control valve to close. Subsequently, the foam will rebound rapidly due to elastic potential energy, triggering the defoaming probe again, causing the CO2 defoaming control system to fall into a high-frequency false trigger oscillation phenomenon. This pseudo-defoaming phenomenon not only reduces defoaming efficiency but also aggravates equipment wear and energy consumption, affecting fermentation stability. Currently, the manufacturing field of special equipment for food, wine, beverage, and tea production, such as high-density, solid, gas, and clean fermentation technology equipment, generally lacks analysis of foam response characteristics, and relying solely on a single threshold control is insufficient to cope with the complex and ever-changing fermentation environment.

[0004] Existing technologies lack the ability to identify the patterns of foam compression and rebound during continuous defoaming cycles, making it impossible to effectively distinguish whether the foam layer has been truly eliminated. This results in delayed control decisions by the CO2 control valve and a tendency to fall into a vicious cycle.

[0005] Therefore, the present invention provides a CO2 defoaming control method for beer production. Summary of the Invention

[0006] The purpose of this invention is to provide a CO2 defoaming control method for beer production to solve the aforementioned background problems.

[0007] The objective of this invention can be achieved through the following technical solution: a CO2 defoaming control method for beer production, comprising: The system synchronously acquires the level signals of the demister probe and the control valve, identifies whether the demister probe is in contact with foam, and the opening or closing events of the control valve, and performs dynamic dual-time analysis to generate dynamic descriptors. A sliding time window is set to collect dynamic descriptors of historical defoaming cycles to construct a response trend sequence, extract the compression change relationship and the rebound change relationship, identify the foam elimination effect of the current defoaming cycle, and calculate the state factor; If the foam elimination effect is poor, obtain the opening interval of adjacent control valves combined with the state factor to determine whether the current defoaming cycle has fallen into high-frequency false touch oscillation; if it has fallen into high-frequency false touch oscillation, record the oscillation depth. Based on the oscillation depth of the current defoaming cycle, calculate the shortest duration, implement forced oscillation defoaming operation and execute defoaming control logic; if the forced oscillation defoaming operation is completed, calculate the state factor of the next defoaming cycle and analyze whether the high-frequency false oscillation has been cleared.

[0008] Furthermore, the process of generating dynamic descriptors through dynamic bi-temporal analysis is as follows: The level signals of the demister probe and the control valve are acquired synchronously, and the compression response time and rebound recovery time are calculated by performing response time delay calculation. The compression response time and rebound recovery time are combined into a dynamic descriptor.

[0009] Furthermore, the process of calculating the response delay is as follows: The sampling moment when the level signal of the defoaming probe first changes from high level to low level is taken as the compression release moment, and the search starts from the compression release moment. The sampling moment when the defoaming probe first changes from low level to high level is taken as the rebound contact moment. The sampling moment when the control valve's level signal first changes from low to high is taken as the compression start moment of the control valve opening event, and the search starts from the compression start moment. The sampling moment when the control valve first changes from high to low is taken as the rebound start moment of the control valve closing event. The compression response time is obtained by calculating the difference between the compression disengagement time and the compression start time of the control valve opening event. The rebound recovery time is obtained by calculating the difference between the rebound contact time and the rebound start time of the control valve closing event.

[0010] Furthermore, the process of identifying the foam elimination effect of the current defoaming cycle is as follows: The dynamic descriptors within the sliding time window are obtained and processed to obtain the response trend sequence. Extrapolation deviation analysis is then performed to obtain the compression response shortening and rebound recovery shortening. If the compression response shortening is greater than zero and the rebound recovery shortening is greater than zero, then the foam elimination effect of the current defoaming cycle is determined to be poor.

[0011] Furthermore, the process of performing extrapolation bias analysis is as follows: Obtain the compression response trend slope and rebound recovery trend slope of the response trend sequence, as well as the compression response time and rebound recovery time actually measured in the current defoaming cycle; The expected compression response time is calculated by combining the compression response trend slope with the compression response time corresponding to the last defoaming cycle in the response trend sequence and using a linear extrapolation relationship; the expected rebound recovery time is calculated by combining the rebound recovery trend slope with a linear extrapolation relationship. The difference between the expected compression response time and the actual compression response time is processed to obtain the compression response shortening amount; the difference between the expected rebound recovery time and the actual rebound recovery time is processed to obtain the rebound recovery shortening amount.

[0012] Furthermore, the process of calculating the state factor is as follows: The compression response shortening and the springback recovery shortening are multiplied to obtain the response recovery amount; the expected compression response time and the expected springback recovery time are multiplied to obtain the compression-springback product; the ratio of the response recovery amount to the compression-springback product is calculated to obtain the state factor.

[0013] Furthermore, the process of determining whether the current defoaming cycle has fallen into high-frequency false trigger oscillation is as follows: Obtain the compression separation time and rebound contact time of each defoaming cycle in the sliding time window, and perform difference processing to obtain the single cycle time; The expected shortest defoaming time is obtained by arithmetically averaging the single cycle time of each defoaming cycle within the sliding time window. If the state factor of the current demisting cycle is greater than zero, and the opening interval between adjacent control valves is less than or equal to the expected shortest demisting time, then the current demisting cycle is determined to have fallen into high-frequency false trigger oscillation and the oscillation depth is recorded.

[0014] Furthermore, the process of recording the oscillation depth is as follows: If it is determined that the current defoaming cycle has fallen into high-frequency false contact oscillation, and the previous defoaming cycle did not fall into high-frequency false contact oscillation, then the oscillation depth is assigned a value of one. If it is determined that the current defoaming cycle is caught in high-frequency false trigger oscillation, and the previous defoaming cycle was also caught in high-frequency false trigger oscillation, then the oscillation depth will be updated to the oscillation depth of the previous defoaming cycle plus one.

[0015] Furthermore, the process of executing the defoaming control logic is as follows: Mark the sampling point corresponding to the current defoaming cycle falling into high-frequency false oscillation as the starting sampling point. Starting from the starting sampling point, extend the time length corresponding to the shortest maintenance time along the time axis in the positive direction to obtain the forced maintenance time point. Forced defoaming with oscillation is performed within the shortest duration. If the sampling point does not reach the forced duration, the control valve will not be closed regardless of whether the level signal of the defoaming probe changes from high to low. If the sampling point reaches the forced maintenance time point, the level signal of the current defoaming probe is detected. If it is low, the control valve is closed; if it is high, the control valve is not closed until the level signal of the defoaming probe changes from high to low.

[0016] Furthermore, the process for determining whether the high-frequency accidental oscillation has been cleared is as follows: Calculate the state factor of the next defoaming cycle after the forced defoaming process. If the state factor of the next defoaming cycle is equal to zero, it means that the high-frequency false oscillation has been cleared. If the state factor of the next defoaming cycle is greater than zero, the oscillation elimination process will be repeated in the next defoaming cycle until the state factor equals zero.

[0017] The beneficial effects of this invention are as follows: 1. This invention collects the level signals of the defoaming probe and the control valve, whether the defoaming probe is in contact with foam, and the opening or closing events of the control valve, and performs dynamic dual-time analysis to generate a dynamic descriptor. This solves the problem that conventional CO2 defoaming control cannot distinguish whether the foam is ruptured or caused by the compression of CO2 gas flow, thus avoiding misjudgment when the control valve is immediately closed after the defoaming probe leaves the foam. By setting a sliding time window to collect dynamic descriptors of historical defoaming cycles, a response trend sequence is constructed, the compression change relationship and the rebound change relationship are extracted, the foam elimination effect of the current defoaming cycle is identified, and the state factor is calculated. This invention can sense the degree of foam rebound caused by the compression of CO2 gas flow in real time, thereby assessing the severity of the false defoaming phenomenon and identifying whether the current defoaming action is an effective CO2 blowing or has begun to fall into an ineffective elastic disturbance cycle.

[0018] 2. If the foam elimination effect is poor, obtain the opening interval of adjacent control valves and the state factor to determine whether the current demisting cycle has fallen into high-frequency false trigger oscillation; if it has, record the oscillation depth; it can identify whether the current demisting cycle has entered high-frequency false trigger oscillation caused by elastic compression rebound, which can effectively solve the problem that the traditional control valve control logic mistakenly interprets frequent repeated triggers as multiple normal demisting operations, resulting in a large waste of CO2 and the inability to remove foam; it provides a basis for subsequent forced intervention; it calculates the shortest maintenance time based on the oscillation depth of the current demisting cycle, implements oscillation forced demisting operation and executes the demisting control logic; if the oscillation forced demisting operation is completed, it calculates the state factor of the next demisting cycle to determine whether the high-frequency false trigger oscillation has been eliminated; it can forcibly open the control valve according to the shortest maintenance time of the control valve opening, use the state factor to determine the foam elimination effect and restore the CO2 control valve's normal control logic in a timely manner, significantly improving the actual demisting effect. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is a flowchart of the steps of a CO2 defoaming control method for beer production according to the present invention; Figure 2This is a logic diagram in the present invention for determining whether the current defoaming cycle has fallen into high-frequency false oscillation and recording the oscillation depth. Figure 3 This is a functional block diagram of a CO2 defoaming control system for beer production according to the present invention. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0022] Example 1 like Figure 1 As shown, a CO2 defoaming control method for beer production includes: Step 1: Synchronously acquire the level signals of the demister probe and the control valve, identify whether the demister probe is in contact with foam, and the opening or closing events of the control valve, and perform dynamic dual-time analysis to generate dynamic descriptors; The process of simultaneously acquiring the level signals of the demister probe and the control valve, identifying whether the demister probe is in contact with foam, and the opening or closing event of the control valve is as follows: In the CO2 defoaming control system of beer production, a signal acquisition and processing unit is constructed. The signal acquisition and processing unit uses the same clock source as the time base to synchronously acquire the level signals of the defoaming probe and the control valve at each sampling point. Among them, the control valve refers to the actuator that directly controls the flow of high-pressure CO2 gas used for defoaming; the sampling time corresponding to each sampling point is taken as the sampling time; If the level signal of the defoaming probe is high, it means that the defoaming probe is in contact with the foam. If the level signal of the defoaming probe is low, it means that the defoaming probe is not in contact with the foam and is in a separated state. If the control valve's signal level is high, it indicates that the control valve is in the open state; if the control valve's signal level is low, it indicates that the control valve is in the closed state. The process of generating dynamic descriptors through dynamic bi-time analysis is as follows: Identify the process of the control valve's level signal transitioning from low to high, mark each transition as a control valve opening event, and take the sampling moment corresponding to the first transition of the control valve's level signal from low to high as the compression start moment of the control valve opening event. For each control valve opening event, starting from the compression start time of the control valve opening event, the sampling moment when the level signal of the defoaming probe first changes from low to high level is extracted along the time axis as the compression discontinuation moment. The compression response time is obtained by calculating the difference between the compression disengagement time and the compression start time of the control valve opening event. The compression response time refers to the time it takes for the foam layer to be elastically compressed under the impact of CO2 airflow, causing the demister probe to detach from the foam contact. Starting from the compression start time, construct a waiting time window with a duration of 10 seconds; If the level signal of the defoaming probe is low during the waiting time window, it means that the defoaming probe has not been detected to re-contact the foam, and it is confirmed that the foam has been eliminated. The control valve opening event does not have a rebound contact moment or rebound recovery time. If the level signal of the defoaming probe changes from low to high within the waiting time window, it indicates that the defoaming probe has contacted the foam, confirming that the foam has rebounded, causing the defoaming probe to contact the foam again; the sampling time corresponding to the first change of the defoaming probe from low to high level is taken as the rebound contact time. After capturing the control valve opening event, identify the process of the first jump from the open state to the closed state of the control valve, mark this jump process as the control valve closing event, and take the sampling time corresponding to the first jump as the rebound start time of the control valve closing event; The rebound recovery time is obtained by calculating the difference between the rebound contact moment and the rebound start moment of the control valve closing event; It should be noted that the rebound recovery time refers to the time it takes for the compressed foam layer to elastically rebound and re-contact the defoaming probe after the CO2 gas flow is removed. The compression response time and rebound recovery time obtained from the control valve opening event and its corresponding control valve closing event are combined into a binary feature set as a dynamic descriptor; the dynamic descriptor represents the mechanical response characteristics of foam in a single defoaming action; Step 2: Set a sliding time window to collect dynamic descriptors of historical defoaming cycles to construct a response trend sequence, extract the compression change relationship and rebound change relationship, identify the foam elimination effect of the current defoaming cycle, and calculate the state factor; The process of constructing a response trend sequence by setting a sliding time window to collect historical defoaming cycles using a dynamic descriptor is as follows: The dynamic descriptor of the current demisting cycle is obtained in the signal acquisition and processing unit, and the dynamic descriptors recorded in the five consecutive demisting cycles before the current demisting cycle are extracted; a sliding time window is set based on the current demisting cycle, with the length of the sliding time window being five consecutive demisting cycles and the step size being one demisting cycle. If a defoaming cycle without a bounce start time and bounce recovery time occurs during the extraction of dynamic descriptors in the sliding time window, the defoaming cycle is skipped and the extraction continues forward until dynamic descriptors for five consecutive defoaming cycles are extracted. It is understandable that the demisting cycle refers to a complete demisting action execution process consisting of a complete control valve opening event and the first control valve closing event that occurs after that control valve opening event. The dynamic descriptors of the extracted sliding time window are arranged in chronological order of the defoaming cycle to obtain the response trend sequence. The process of extracting the compression and rebound relationship, identifying the foam elimination effect of the current defoaming cycle, and calculating the state factor is as follows: The compression response time of each defoaming cycle in the response trend sequence is sorted out to obtain the compression response time sequence. Least square linear fitting is then performed to calculate the linear trend slope of the compression response time sequence. The result is used as the compression response trend slope. The expected compression response time of the current demisting cycle is obtained by calculating the compression response time corresponding to the last demisting cycle in the compression response time series and the slope of the compression response trend through linear extrapolation. The rebound recovery time of each defoaming cycle in the response trend sequence is sorted out to obtain the rebound recovery time sequence. Least square linear fitting is then performed to calculate the linear trend slope of the rebound recovery time sequence. The result is used as the rebound recovery trend slope. The expected rebound recovery time for the current defoaming cycle is obtained by calculating the rebound recovery time corresponding to the last defoaming cycle in the rebound recovery time series and the slope of the rebound recovery trend through linear extrapolation. Extract the actual compression response time and the actual rebound recovery time of the current defoaming cycle from the signal acquisition and processing unit, and record them as the actual compression response time and the actual rebound recovery time, respectively. The difference between the expected compression response time and the actual compression response time is calculated to obtain the compression response reduction; the difference between the expected rebound recovery time and the actual rebound recovery time is calculated to obtain the rebound recovery reduction. If the compression response shortening is greater than zero and the rebound recovery shortening is greater than zero, then it is determined that the foam rebound in the current defoaming cycle is more severe than the historical trend, and the foam elimination effect is poor. The compression response shortening and the springback recovery shortening are multiplied to obtain the response recovery amount; the expected compression response time and the expected springback recovery time are multiplied to obtain the compression-springback product; the ratio of the response recovery amount to the compression-springback product is calculated to obtain the state factor. It should be noted that the physical basis of the state factor calculation method is as follows: Under the impact of high-pressure CO2 airflow, the foam layer undergoes elastic compression rather than actual rupture. The defoaming probe detaches and emits a false defoaming signal, while elastic potential energy accumulates inside the foam. After the airflow is removed, the foam rebounds rapidly. The calculation of the state factor utilizes a continuous multi-cycle compression and rebound time series. By linear extrapolation, the expected time should be obtained if there is no aggravation in the current cycle. Then, the product of the actual deviation from the expected shortening and the product of the expected time are multiplied to obtain the ratio. This dimensionless processing is based on the mechanical response law of elastic compression and rebound coupling. The relative deviation in two directions is used to comprehensively quantify the degree of deviation of the false defoaming from normal foam rupture. When the compression response shortening is less than or equal to zero, or the rebound recovery shortening is less than or equal to zero, it is determined that the foam rebound in the current defoaming cycle has not intensified relative to the historical trend, the foam layer is in a stable or alleviated period, the foam elimination effect is good, and the state factor is directly assigned to zero. It should be noted that the physical meaning of the state factor is: a dimensionless measure of the actual foam-breaking effect of a single defoaming action, directly characterizing whether the foam is truly broken or only undergoes elastic pseudo-decay; when the state factor is equal to zero, it means that the compression response time or rebound recovery time has not shortened significantly relative to the historical trend, the foam rebound has not intensified, the defoaming process is dominated by airflow blowing, and the foam-breaking effect is substantially good; when the state factor is greater than zero and the larger the value, the more drastic the actual compression and rebound time shortens synchronously with the expected trend, the more dominant the elastic compression and rapid rebound of the foam layer, the more serious the pseudo-defoaming phenomenon, the less foam is truly eliminated in a single defoaming action, and the worse the actual foam-breaking effect. The technical solution of this invention is as follows: Simultaneously acquire the level signals of the defoaming probe and the control valve, whether the defoaming probe is in contact with foam, and the opening or closing events of the control valve, and perform dynamic dual-time analysis to generate a dynamic descriptor; this solves the problem that conventional CO2 defoaming control cannot distinguish whether the foam is ruptured or caused by CO2 gas compression, thus avoiding misjudgment when the control valve is immediately closed after the defoaming probe detaches from the foam; a sliding time window is set to acquire dynamic descriptors from historical defoaming cycles to construct a response trend sequence, extract the compression change relationship and rebound change relationship, identify the foam elimination effect of the current defoaming cycle, and calculate the state factor; it can perceive the degree of foam rebound caused by CO2 gas compression in real time, thereby assessing the severity of the false defoaming phenomenon, identifying whether the current defoaming action is effective CO2 blowing, or has begun to fall into an ineffective elastic disturbance cycle.

[0023] Example 2 Please see Figures 1-2 As shown, a CO2 defoaming control method for beer production includes: Step 3: If the foam elimination effect is poor, obtain the opening interval of adjacent control valves combined with the state factor to determine whether the current defoaming cycle has fallen into high-frequency false contact oscillation; if it has fallen into high-frequency false contact oscillation, record the oscillation depth. If the foam elimination effect is poor, the process of determining whether the current defoaming cycle has fallen into high-frequency false trigger oscillation is as follows: (This is based on obtaining the opening interval of adjacent control valves and the state factor.) Based on the sliding time window in step two, extract the control valve opening time of the current demisting cycle and the control valve opening time of the previous demisting cycle. The difference between the opening time of the control valve in the current demisting cycle and the opening time of the control valve in the previous demisting cycle is processed to obtain the opening interval of adjacent control valves. The interval between adjacent control valve openings is the time interval between two consecutive control valve openings. This time interval reflects the actual time elapsed from the CO2 injection triggered by the previous demisting action to the CO2 injection triggered by the next demisting action. Obtain the compression release time and rebound contact time for each defoaming cycle within the sliding time window; It should be noted that the compression release moment refers to the moment when the demister probe first changes from the contact state to the release state; the rebound contact moment refers to the moment when the demister probe changes from the release state to the contact state again within the sliding time window. The single cycle time of each demisting cycle is obtained by performing difference processing on the compression separation time and the rebound contact time of each demisting cycle in the sliding time window. It should be noted that the single cycle time refers to the duration of one complete elastic response cycle that the foam layer actually undergoes from the time it is compressed and detached from the defoaming probe by the CO2 gas flow during the defoaming cycle, until the control valve is closed, the gas flow is removed, and the foam rebounds and re-contacts the defoaming probe. The arithmetic mean of the single cycle time of each defoaming cycle within the sliding time window is used as the expected shortest defoaming time. The physical significance of the expected shortest defoaming time calculation method is as follows: it uses the shortest time required for the foam layer to rebound and re-contact the defoaming probe after being pressed away by the CO2 gas flow from the defoaming probe in multiple historical defoaming cycles to the point where it rebounds after the control valve is closed, representing the characteristic time scale of the current foam elastic recovery speed; it is dynamically updated with the actual mechanical response of the foam and serves as a threshold for judging high-frequency false contact oscillation. Obtain the state factor of the current defoaming cycle; If the state factor of the current demisting cycle is greater than zero, and the opening interval between adjacent control valves is less than or equal to the expected shortest demisting time, then the current demisting cycle is determined to have fallen into high-frequency false trigger oscillation. If the state factor of the current demisting cycle is equal to zero, or the opening interval of adjacent control valves is greater than the expected shortest demisting time, then the current demisting cycle is determined not to have fallen into high-frequency false contact oscillation and is marked as a normal demisting cycle. If a high-frequency false trigger oscillation occurs, the process of recording the oscillation depth is as follows: If it is determined that the current defoaming cycle has fallen into high-frequency false contact oscillation, and the previous defoaming cycle was determined not to have fallen into high-frequency false contact oscillation, it indicates that the current defoaming cycle has entered the high-frequency false contact oscillation state for the first time, and the oscillation depth is assigned a value of one. If it is determined that the current defoaming cycle has fallen into high-frequency false touch oscillation, and the previous defoaming cycle was also determined to have fallen into high-frequency false touch oscillation, it indicates that the false extinction of elastic compression of the foam layer has continued from the previous defoaming cycle to the current defoaming cycle without being interrupted. In this case, the oscillation depth will be updated to the oscillation depth of the previous defoaming cycle plus one. If the current defoaming cycle is marked as a normal defoaming cycle, it indicates that the foam layer has been substantially broken down by the CO2 airflow or the rebound trend has been effectively suppressed during this defoaming action, and the oscillation depth is assigned to zero; It should be noted that the oscillation depth directly records the number of consecutive defoaming cycles in which the foam layer is repeatedly compressed and rebounded due to the pseudo-regression effect of elastic compression, and is never substantially broken. The larger this value is, the stronger the persistence driven by the pseudo-defoaming effect, and the more stubborn the foam is in an ineffective disturbance state where it is repeatedly compressed by the CO2 airflow but cannot be completely broken. Step 4: Calculate the shortest duration based on the oscillation depth of the current defoaming cycle, implement forced oscillation defoaming operation and execute defoaming control logic; if the forced oscillation defoaming operation is completed, calculate the state factor of the next defoaming cycle and determine whether the high-frequency false oscillation has been cleared. The process of calculating the shortest duration of oscillation based on the oscillation depth of the current defoaming cycle, implementing forced oscillation defoaming operation, and executing defoaming control logic is as follows: If it is determined that the current defoaming cycle has fallen into high-frequency false trigger oscillation, extract the oscillation depth of the current defoaming cycle and the expected shortest defoaming time within the sliding time window of the current defoaming cycle; The product of the oscillation depth of the current defoaming cycle and the expected shortest defoaming time is used as the shortest maintenance duration. It should be noted that the physical basis for the method of calculating the shortest duration of maintenance is as follows: the oscillation depth records the number of defoaming cycles in which the foam layer fails to be substantially broken due to the pseudo-decay effect of elastic compression; the expected shortest defoaming time represents the typical duration for the foam layer to complete one complete elastic response cycle from being compressed and detached from the defoaming probe by the CO2 gas flow to rebounding and re-contacting the defoaming probe in the current state; multiplying the oscillation depth by the expected shortest defoaming time indicates the duration of continuous impact of CO2 gas flow necessary to cover multiple consecutive pseudo-decay effects of elastic compression, thereby forcibly breaking the repeated compression-rebound cycle of the foam layer; Mark the sampling point corresponding to the current defoaming cycle falling into high-frequency false oscillation as the starting sampling point. Starting from the starting sampling point, extend the time length corresponding to the shortest maintenance time along the time axis in the positive direction to obtain the forced maintenance time point. Forced defoaming is performed during the shortest duration of maintenance. If the sampling point does not reach the forced maintenance time, the signal acquisition and processing unit will block the control valve closing logic triggered by the high-to-low level transition of the defoaming probe's signal. That is, the control valve will remain open during the shortest duration of maintenance, and the control valve will not be closed regardless of whether the defoaming probe's signal transitions from high to low. If the sampling point reaches the forced maintenance time point, the signal acquisition and processing unit will immediately unshield and immediately detect the current level of the defogging probe. If it is low, the control valve will be closed directly. If it is high, the control valve will not be closed until the level signal of the defogging probe changes from high to low. The process of calculating the state factor for the next defoaming cycle and determining whether the high-frequency accidental oscillation has been cleared after the forced defoaming operation is completed is as follows: Calculate the state factor of the next defoaming cycle after the forced defoaming process. If the state factor of the next defoaming cycle is equal to zero, it means that the high-frequency false oscillation of the next defoaming cycle has been cleared. The signal acquisition and processing unit determines that the actual effect of foam dissipation has returned to the state dominated by CO2 airflow blowing, and the false dissipation phenomenon of elastic compression of the foam layer has been eliminated. If the state factor of the next defoaming cycle is greater than zero, then the determination oscillation elimination process of steps three to four will be repeated in the next defoaming cycle until the state factor is equal to zero. The physical significance of repeating the determination and oscillation elimination process in steps three to four is that the system can sense in real time whether the mechanical response characteristics of the elastic compression and rebound of the foam layer have been substantially destroyed after each forced extension of CO2 airflow impact, and dynamically adjust the intensity of subsequent forced action accordingly, forming a closed-loop control with the actual foam breaking state as feedback, ensuring that unnecessary excessive jetting is avoided while completely dismantling the pseudo-dissipation oscillation of elastic compression. The technical solution of this invention is as follows: If the foam elimination effect is poor, the opening interval of adjacent control valves is obtained in combination with the state factor to determine whether the current defoaming cycle has fallen into high-frequency false trigger oscillation; if it has fallen into high-frequency false trigger oscillation, the oscillation depth is recorded; it can identify whether the current defoaming cycle has entered high-frequency false trigger oscillation caused by elastic compression rebound, which can effectively solve the problem that the traditional control valve control logic mistakenly identifies frequent repeated triggers as multiple normal defoamings, resulting in a large waste of CO2 and the inability to remove foam; it provides a basis for subsequent forced intervention; the shortest maintenance time is calculated based on the oscillation depth of the current defoaming cycle, and the oscillation forced defoaming operation is implemented and the defoaming control logic is executed; if the oscillation forced defoaming operation is completed, the state factor of the next defoaming cycle is calculated to determine whether the high-frequency false trigger oscillation has been cleared; it can forcibly open the control valve according to the shortest maintenance time of the control valve opening, use the state factor to determine the foam elimination effect, and restore the CO2 control valve's normal control logic in a timely manner; it significantly improves the actual defoaming effect.

[0024] Example 3 Please see Figure 3 As shown, a CO2 defoaming control system for beer production includes the following modules: Signal Feature Module: Synchronously acquires the level signals of the defoaming probe and the control valve, whether the defoaming probe is in contact with foam, and the opening or closing events of the control valve, and performs dynamic dual-time analysis to generate dynamic descriptors; State assessment module: Set a sliding time window to collect dynamic descriptors of historical defoaming cycles to construct response trend sequences, extract compression and rebound relationship, identify the foam elimination effect of the current defoaming cycle, and calculate state factors; Oscillation Diagnosis Module: If the foam elimination effect is poor, obtain the opening interval of adjacent control valves combined with the state factor to determine whether the current defoaming cycle has fallen into high-frequency false touch oscillation; if it has fallen into high-frequency false touch oscillation, record the oscillation depth. Forced defoaming module: Calculates the shortest duration based on the oscillation depth of the current defoaming cycle, performs forced defoaming operation and executes defoaming control logic; if the forced defoaming operation is completed, calculates the state factor of the next defoaming cycle and determines whether the high-frequency false oscillation has been cleared.

[0025] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for CO2 defoaming control in beer production, characterized in that: include: The system synchronously acquires the level signals of the demister probe and the control valve, identifies whether the demister probe is in contact with foam, and the opening or closing events of the control valve, and performs dynamic dual-time analysis to generate dynamic descriptors. A sliding time window is set to collect dynamic descriptors of historical defoaming cycles to construct a response trend sequence, extract the compression change relationship and the rebound change relationship, identify the foam elimination effect of the current defoaming cycle, and calculate the state factor; If the foam elimination effect is poor, obtain the opening interval of adjacent control valves combined with the state factor to determine whether the current defoaming cycle has fallen into high-frequency false touch oscillation; if it has fallen into high-frequency false touch oscillation, record the oscillation depth. Calculate the shortest duration of maintenance based on the oscillation depth of the current defoaming cycle, implement forced oscillation defoaming operation, and execute defoaming control logic; If the forced defoaming operation is completed, calculate the state factor for the next defoaming cycle and analyze whether the high-frequency accidental oscillation has been cleared.

2. The CO2 defoaming control method for beer production according to claim 1, characterized in that: The process of generating dynamic descriptors through dynamic bi-time analysis is as follows: The level signals of the demister probe and the control valve are acquired synchronously, and the compression response time and rebound recovery time are calculated by performing response time delay calculation. The compression response time and rebound recovery time are combined into a dynamic descriptor.

3. The CO2 defoaming control method for beer production according to claim 2, characterized in that: The process of calculating the response delay is as follows: The sampling moment when the level signal of the defoaming probe first changes from high level to low level is taken as the compression release moment, and the search starts from the compression release moment. The sampling moment when the defoaming probe first changes from low level to high level is taken as the rebound contact moment. The sampling moment when the control valve's level signal first changes from low to high is taken as the compression start moment of the control valve opening event, and the search starts from the compression start moment. The sampling moment when the control valve first changes from high to low is taken as the rebound start moment of the control valve closing event. The compression response time is obtained by calculating the difference between the compression disengagement time and the compression start time of the control valve opening event. The rebound recovery time is obtained by calculating the difference between the rebound contact time and the rebound start time of the control valve closing event.

4. The CO2 defoaming control method for beer production according to claim 1, characterized in that: The process of identifying the foam elimination effect of the current defoaming cycle is as follows: The dynamic descriptors within the sliding time window are obtained and processed to obtain the response trend sequence. Extrapolation deviation analysis is then performed to obtain the compression response shortening and rebound recovery shortening. If the compression response shortening is greater than zero and the rebound recovery shortening is greater than zero, then the foam elimination effect of the current defoaming cycle is determined to be poor.

5. A method for CO2 defoaming control in beer production according to claim 4, characterized in that: The process of performing extrapolation bias analysis is as follows: Obtain the compression response trend slope and rebound recovery trend slope of the response trend sequence, as well as the compression response time and rebound recovery time actually measured in the current defoaming cycle; The expected compression response time is calculated by combining the compression response trend slope with the compression response time corresponding to the last defoaming cycle in the response trend sequence through linear extrapolation. The expected rebound recovery time is calculated by combining the rebound recovery trend slope with the rebound recovery time through linear extrapolation. The difference between the expected compression response time and the actual compression response time is processed to obtain the compression response shortening amount; the difference between the expected rebound recovery time and the actual rebound recovery time is processed to obtain the rebound recovery shortening amount.

6. The CO2 defoaming control method for beer production according to claim 1, characterized in that: The process of calculating the state factor is as follows: The compression response shortening and the springback recovery shortening are multiplied to obtain the response recovery amount; the expected compression response time and the expected springback recovery time are multiplied to obtain the compression-springback product. The state factor is obtained by calculating the ratio of the response recovery to the compression-rebound product.

7. The CO2 defoaming control method for beer production according to claim 1, characterized in that: The process for determining whether the current defoaming cycle has fallen into high-frequency false trigger oscillation is as follows: Obtain the compression separation time and rebound contact time of each defoaming cycle in the sliding time window, and perform difference processing to obtain the single cycle time; The expected shortest defoaming time is obtained by arithmetically averaging the single cycle time of each defoaming cycle within the sliding time window. If the state factor of the current demisting cycle is greater than zero, and the opening interval between adjacent control valves is less than or equal to the expected shortest demisting time, then the current demisting cycle is determined to have fallen into high-frequency false trigger oscillation and the oscillation depth is recorded.

8. A method for CO2 defoaming control in beer production according to claim 7, characterized in that: The process of recording the oscillation depth is as follows: If it is determined that the current defoaming cycle has fallen into high-frequency false contact oscillation, and the previous defoaming cycle did not fall into high-frequency false contact oscillation, then the oscillation depth is assigned a value of one. If it is determined that the current defoaming cycle is caught in high-frequency false trigger oscillation, and the previous defoaming cycle was also caught in high-frequency false trigger oscillation, then the oscillation depth is updated to the oscillation depth of the previous defoaming cycle plus one.

9. A method for CO2 defoaming control in beer production according to claim 1, characterized in that: The process of executing the defoaming control logic is as follows: Mark the sampling point corresponding to the current defoaming cycle falling into high-frequency false oscillation as the starting sampling point. Starting from the starting sampling point, extend the time length corresponding to the shortest maintenance time along the time axis in the positive direction to obtain the forced maintenance time point. Forced defoaming with oscillation is performed within the shortest duration. If the sampling point does not reach the forced duration, the control valve will not be closed regardless of whether the level signal of the defoaming probe changes from high to low. If the sampling point reaches the forced maintenance time point, the level signal of the current defoaming probe is detected. If it is low, the control valve is closed; if it is high, the control valve is not closed until the level signal of the defoaming probe changes from high to low.

10. A method for CO2 defoaming control in beer production according to claim 1, characterized in that: The process for determining whether high-frequency accidental oscillations have been cleared is as follows: Calculate the state factor of the next defoaming cycle after the forced defoaming process. If the state factor of the next defoaming cycle is equal to zero, it means that the high-frequency false oscillation has been cleared. If the state factor of the next defoaming cycle is greater than zero, the oscillation elimination process will be repeated in the next defoaming cycle until the state factor equals zero.

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