Fluid intelligent regulating method based on adaptive control algorithm

Abstract

The application discloses a kind of fluid intelligent regulation method based on adaptive control algorithm, it is related to fluid control technical field, comprising: target flow, real-time flow, downstream pressure, pump speed and valve opening are collected;When real-time flow is lower than target flow and downstream pressure does not reach safety boundary, supply pressure pulsation period is determined according to pump speed, and pressure flow variation in period is read when pump valve instruction is unchanged;According to the change of downstream pressure from low to high, from high to low, pressure rise half cycle and pressure fall half cycle are divided, and the first occurrence position of real-time flow effective increment is determined;According to first occurrence position, allow pump, delayed regulation or pressure protection mode is generated, and pump speed correction, waiting time or pressure direction control is formed, so that real-time flow meets the standard and downstream pressure is lower than safety boundary.The application can distinguish and respond in time, lag response and invalid supply pressure without additional test control, reduce the risk of pressure anomaly and flow overshoot caused by blind pump.

Description

Technical Field

[0001] This invention relates to the field of fluid control technology, and in particular to a fluid intelligent regulation method based on an adaptive control algorithm. Background Technology

[0002] In scenarios such as industrial water supply, chemical transportation, cooling circulation, and hydraulic actuation, fluid regulation typically requires maintaining a dynamic balance between target flow rate, pipeline pressure, and the capacity of the actuator. Conventional fluid regulation methods based on adaptive control algorithms often establish closed-loop control through feedback data from flow meters, pressure sensors, pump drivers, and regulating valves. The pump speed or valve opening is adjusted based on the deviation between the real-time flow rate and the target flow rate to achieve stable regulation of the pipeline transportation process.

[0003] In the above methods, the control quantity is mostly based on the flow deviation and pressure amplitude, and rarely utilizes the difference between the pump's natural pressure pulsation during the half-cycle of pressure increase and the half-cycle of pressure decrease. It is difficult to judge in time whether the pressure change has been converted into the delivery flow. At the same time, when the real-time flow is low, the lagging flow response or invalid pressure is easily used as an effective basis for increasing the pump, resulting in insufficient matching between pump speed regulation and the actual delivery capacity of the pipeline. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a fluid intelligent regulation method based on an adaptive control algorithm to solve the problems of difficulty in accurately determining whether changes in supply pressure are promptly converted into delivery flow rate and insufficient matching between pump speed regulation and the actual delivery capacity of the pipeline in existing technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a fluid intelligent regulation method based on an adaptive control algorithm, comprising: acquiring target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening of the target pipeline; when the real-time flow rate is lower than the target flow rate and the downstream pressure has not reached the pressure safety boundary, determining the pressure pulsation cycle based on the pump speed, and reading the pressure and flow rate changes within the cycle while keeping the pump speed command and valve opening command unchanged; dividing the pressure pulsation cycle into a pressure rise half-cycle and a pressure fall half-cycle based on the changes in downstream pressure from low to high and from high to low within the pressure pulsation cycle, and determining the first occurrence position of the effective increment of real-time flow rate; judging whether the pressure pulsation is timely converted into delivery flow rate based on the correspondence between the first occurrence position of the effective increment of real-time flow rate and the pressure rise half-cycle and pressure fall half-cycle, and generating a regulation permission mode that allows pump increase, delayed regulation, or pressure reduction protection; generating a pump speed correction amount, waiting time, or pressure reduction direction control amount according to the regulation permission mode, so that the real-time flow rate of the target pipeline enters the target allowable range and the downstream pressure is lower than the pressure safety boundary.

[0007] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the pressure safety boundary includes: determined by subtracting the maximum permissible error of the pressure sensor and the control margin from the allowable downstream pressure of the target pipeline design; the allowable downstream pressure of the target pipeline design includes the minimum permissible pressure among the rated pressures of the target pipeline, joints, seals, and end-use flow equipment; the control margin includes: determined based on the upper limit of the natural fluctuation of the downstream pressure during the stable delivery phase of the target pipeline.

[0008] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the step of determining the pressure supply pulsation period according to the pump speed includes: determining the pressure supply pulsation period according to the number of natural pressure supply pulsations formed per pump revolution and the pump speed; the number of natural pressure supply pulsations includes being determined according to the pump's discharge structure, for plunger pumps, according to the number of plungers participating in discharge, for gear pumps, according to the number of meshing discharges, and for vane pumps, according to the number of times the vanes pass through the discharge zone.

[0009] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the step of reading the pressure and flow rate changes within a cycle while keeping the pump speed command and valve opening command unchanged includes using the pressure pulsation cycle as the reading window, continuously reading the downstream pressure sampling value and real-time flow sampling value within one pressure pulsation cycle, and arranging the downstream pressure sampling value and real-time flow sampling value according to the same time sequence.

[0010] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the step of dividing the pressure supply pulsation cycle into a pressure rise half-cycle and a pressure fall half-cycle includes: determining the lowest pressure sampling time when the downstream pressure changes from falling to rising, the highest pressure sampling time when the downstream pressure changes from rising to falling after the lowest pressure sampling time, and the next lowest pressure sampling time when the downstream pressure changes from falling to rising again after the highest pressure sampling time within one pressure supply pulsation cycle; defining the time period between the lowest pressure sampling time and the highest pressure sampling time as the pressure rise half-cycle, and defining the time period between the highest pressure sampling time and the next lowest pressure sampling time as the pressure fall half-cycle.

[0011] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, determining the first occurrence position of the real-time flow effective increment includes: taking the real-time flow value at the sampling moment before entering the pressure supply pulsation cycle as the pre-cycle flow value; determining the lower limit of the real-time flow effective increment based on the minimum resolution of the flowmeter and the upper limit of the absolute value of the adjacent sampling flow change during the stable operation phase of the target pipeline; subtracting each real-time flow sampling value within the pressure supply pulsation cycle from the pre-cycle flow value, and determining the corresponding sampling moment as the first occurrence moment of the real-time flow effective increment when the difference first reaches the lower limit of the real-time flow effective increment; determining that no real-time flow effective increment has occurred in this pressure supply pulsation cycle when the increase of each real-time flow sampling value relative to the pre-cycle flow value within the pressure supply pulsation cycle does not reach the lower limit of the real-time flow effective increment.

[0012] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, determining the first occurrence position of the real-time flow effective increment includes: when there is a time when the real-time flow effective increment first occurs, determining a flow occurrence position determination value based on the time when the real-time flow effective increment first occurs, the time when the lowest pressure is sampled, and the time when the next lowest pressure is sampled; determining a pressure rise half-cycle end position boundary value based on the highest pressure sampling time, the time when the lowest pressure is sampled, and the time when the next lowest pressure is sampled; when the flow occurrence position determination value is not greater than the pressure rise half-cycle end position boundary value, determining the first occurrence position of the real-time flow effective increment as the pressure rise half-cycle; when the flow occurrence position determination value is greater than the pressure rise half-cycle end position boundary value, determining the first occurrence position of the real-time flow effective increment as the pressure fall half-cycle.

[0013] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the generation of regulation permission modes that allow pump increase, delayed regulation, or pressure reduction protection includes: when no effective real-time flow increment occurs in the current pressure supply pulsation cycle, the regulation permission mode is determined to be pressure reduction protection regulation mode; when the effective real-time flow increment first occurs at half a cycle of pressure drop, the regulation permission mode is determined to be delayed regulation mode; when the effective real-time flow increment first occurs at half a cycle of pressure rise, the maximum increase of the real-time flow sampling value relative to the flow value before the cycle is further determined; if the maximum increase is not higher than the lower limit of the effective real-time flow increment, the regulation permission mode is determined to be delayed regulation mode; if the maximum increase is higher than the lower limit of the effective real-time flow increment, the regulation permission mode is determined to be pump increase regulation mode.

[0014] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the step of generating pump speed correction according to the regulation permission mode includes: when the regulation permission mode is a pump increase regulation mode, determining the target flow gap coefficient based on the target flow rate and the real-time flow rate at the time of the current control cycle entry judgment; generating the pump speed correction based on the target flow gap coefficient, the flow occurrence position judgment value, the pressure rise half-cycle end position boundary value, the real-time flow maximum increase, and the real-time flow effective increment lower limit; the pump speed correction includes that the pump speed correction is not greater than the maximum allowable pump speed increment in a single control cycle, and the pump speed correction is only generated when the first occurrence position of the real-time flow effective increment is located at the pressure rise half-cycle and the real-time flow maximum increase is higher than the real-time flow effective increment lower limit.

[0015] As a preferred embodiment of the fluid intelligent regulation method based on adaptive control algorithm described in this invention, the step of generating waiting time or pressure reduction direction control quantity according to the regulation permission mode includes: when the regulation permission mode is a delayed regulation mode, determining the waiting time based on the pressure supply pulsation cycle, the flow occurrence location determination value, and the pressure rise half-cycle end location boundary value; keeping the current pump speed command and the current valve opening command unchanged during the waiting time; when the regulation permission mode is a pressure reduction protection regulation mode, prohibiting the increase of pump speed command, and generating pressure reduction direction control quantity based on the current valve opening and downstream pressure; if the downstream pressure reaches the pressure safety boundary and the current valve opening is higher than the minimum safe opening, the pressure reduction direction control quantity is the valve opening retraction amount; if the current valve opening has reached the minimum safe opening, the pressure reduction direction control quantity is the pump speed reduction amount.

[0016] The beneficial effects of this invention are as follows: By utilizing the natural pressure pulsation of the pump to divide the pressure rise half-cycle and the pressure fall half-cycle, it is possible to determine whether the pressure change is effectively converted into the delivery flow without adding additional test control actions; by judging the first occurrence position of the effective increase in real-time flow, it is possible to distinguish between timely response, delayed response and ineffective pressure supply, avoiding blindly increasing the pump when the flow is low; by executing pump increase, waiting or pressure reduction protection according to the adjustment permission method, it is possible to match the pump speed regulation with the actual delivery capacity of the pipeline, reducing the risk of pressure abnormality and flow overshoot. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a fluid intelligent regulation method based on an adaptive control algorithm.

[0019] Figure 2 A schematic diagram for determining the pressure pulsation period.

[0020] Figure 3 This is a schematic diagram illustrating the determination of pressure half-cycle and flow position.

[0021] Figure 4 A diagram illustrating the regulation of permission and control execution.

[0022] Figure 5 A comparative data graph showing the half-cycle of pressure pulsation for different flow response types.

[0023] Figure 6 A comparative data chart showing the safety of downstream pressure under different regulation methods. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0027] Reference Figures 1-6 This is one embodiment of the present invention, which provides a fluid intelligent regulation method based on an adaptive control algorithm, comprising the following steps: S1. Collect the target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening of the target pipeline. When the real-time flow rate is lower than the target flow rate and the downstream pressure has not reached the pressure safety boundary, determine the pressure pulsation cycle based on the pump speed, and read the pressure and flow rate changes within the cycle while keeping the pump speed command and valve opening command unchanged.

[0028] A pressure sensor is installed in the straight pipe section downstream of the pump outlet of the target pipeline, and a flow meter is installed in the effective delivery section of the target pipeline. The pump speed is read at the pump drive end, the current valve opening is read at the feedback end of the regulating valve actuator, and the target flow rate is read from the fluid regulating controller. The target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening are collected according to the same control cycle to form the fluid regulation data for the current control cycle.

[0029] Among them, the target flow rate is the set delivery flow rate that the target pipeline needs to achieve under the current operating conditions; the real-time flow rate is the actual delivery flow rate collected by the flow meter in the current control cycle; the downstream pressure is the pressure collected by the pressure sensor of the downstream straight pipe section of the pump outlet; the pump speed is the actual speed fed back by the pump drive end; and the current valve opening degree is the opening degree value fed back by the regulating valve actuator.

[0030] The pressure safety boundary is determined by subtracting the maximum permissible error of the pressure sensor and the control margin from the allowable downstream pressure of the target pipeline design. The expression is:

[0031] in, Indicates the pressure safety boundary, Indicates the allowable downstream pressure of the target pipeline design. This indicates the maximum permissible error of the pressure sensor. This indicates the control margin.

[0032] It should be noted that the allowable downstream pressure of the target pipeline design is determined by the minimum allowable pressure among the rated pressures of the pipeline, joints, seals, and end-use equipment; the maximum allowable error of the pressure sensor is determined by the pressure sensor calibration certificate; the control margin is determined by the minimum pressure boost response during the equipment commissioning phase. When the pump speed command and valve opening command remain unchanged, and the change in downstream pressure within the stability determination time is less than the maximum allowable error of the pressure sensor, pressure boost adjustments are performed by the minimum adjustable step of the pump speed and the minimum adjustable step of the valve opening, respectively. The maximum increase in downstream pressure relative to the downstream pressure before adjustment within one control cycle after two pressure boost adjustments is recorded, and the higher of the two maximum increases is taken as the control margin. The stability determination time is determined by the higher of the pressure response times corresponding to the two types of minimum adjustable step.

[0033] When the real-time flow rate is not lower than the target flow rate, the fluid control controller maintains the current pump speed command and valve opening command and does not enter the pressure pulsation judgment process.

[0034] When the real-time flow rate is lower than the target flow rate and the downstream pressure reaches the pressure safety boundary, the fluid control controller prohibits increasing the pump speed and enters the pressure reduction protection process.

[0035] When the real-time flow rate is lower than the target flow rate and the downstream pressure has not reached the pressure safety boundary, the fluid control controller keeps the current pump speed command and valve opening command unchanged, and determines the pressure pulsation period based on the pump speed and the number of natural pressure pulsations formed per pump revolution.

[0036] The formula for calculating the pressure pulsation period is as follows:

[0037] in, This indicates the pressure pulsation period. Indicates pump speed. This indicates the number of natural pressure pulsations generated per revolution of the pump.

[0038] It should be noted that, for plunger pumps, the number of natural pressure pulsations per pump revolution is determined by the number of plungers involved in the drainage; for gear pumps, the number of natural pressure pulsations per pump revolution is determined by the number of meshing drainage cycles; and for vane pumps, the number of natural pressure pulsations per pump revolution is determined by the number of times the vanes pass through the drainage zone. This indicates the pump speed in r / min.

[0039] After determining the pressure pulsation cycle, the fluid control system uses the pressure pulsation cycle as a reading window to continuously read the downstream pressure sampling value and real-time flow sampling value within one pressure pulsation cycle. The downstream pressure sampling value, real-time flow sampling value, target flow rate, pump speed, current valve opening, pressure safety boundary, and pressure pulsation cycle are used together as pressure pulsation analysis data.

[0040] S2. Based on the changes in downstream pressure from low to high and from high to low within the pressure pulsation cycle, the pressure pulsation cycle is divided into a pressure rise half-cycle and a pressure fall half-cycle, and the position where the effective increase in real-time flow first occurs is determined.

[0041] The fluid control system reads the pressure pulsation analysis data and uses the pressure pulsation cycle as the analysis window to arrange the downstream pressure sampling value and real-time flow sampling value in the same time series within a pressure pulsation cycle.

[0042] It should be noted that the sampling interval is preferably set to no more than one-twentieth of the pressure pulsation cycle, so that a sufficient number of downstream pressure sampling values ​​and real-time flow sampling values ​​are included in one pressure pulsation cycle, avoiding identification errors caused by a single sampling point during half a cycle of pressure rise and half a cycle of pressure fall.

[0043] Before entering the pressure pulsation cycle analysis window, the real-time flow value at the previous sampling time in the analysis window is recorded as the flow value before the cycle.

[0044] Furthermore, the fluid control system sequentially reads the downstream pressure sampling values ​​within the pressure pulsation cycle analysis window. It first determines the lowest pressure sampling time when the downstream pressure changes from decreasing to increasing, then determines the highest pressure sampling time when the downstream pressure changes from increasing to decreasing after the lowest pressure sampling time, and then determines the next lowest pressure sampling time when the downstream pressure changes from decreasing to increasing again after the highest pressure sampling time.

[0045] The time period between the lowest pressure sampling time and the highest pressure sampling time is defined as the pressure rise half-cycle, and the time period between the highest pressure sampling time and the next lowest pressure sampling time is defined as the pressure fall half-cycle.

[0046] Furthermore, to avoid flow meter resolution errors and natural fluctuations in stable delivery being mistaken for effective delivery flow, the lower limit of the effective increment of real-time flow is first determined, expressed as:

[0047] in, This indicates the lower limit of the effective increase in real-time traffic. Indicates the minimum resolution of the flow meter. This indicates the upper limit of the absolute value of the change in flow rate between adjacent samples during the stable operation phase of the target pipeline.

[0048] It should be noted that the stable operation phase of the target pipeline refers to the operation phase in which the pump speed command and valve opening command remain unchanged, the real-time flow rate is within the target allowable range, and the downstream pressure is below the pressure safety boundary. During the stable operation phase of the target pipeline, the absolute values ​​of the flow changes of adjacent samples are collected and sorted from smallest to largest. The sorted values ​​that can cover 95% of the stable fluctuation samples are read as the upper limit of stable fluctuations, which is used to exclude the influence of normal natural fluctuations and a small number of occasional spikes on the effective judgment of real-time flow increments.

[0049] It should also be noted that the target allowable range is determined by the maximum value among the target pipeline service condition allowable flow deviation, the stable operating flow deviation of the end-user equipment, and the maximum allowable error of the flow meter. The target flow rate minus the allowable deviation is used as the lower limit, and the target flow rate plus the allowable deviation is used as the upper limit. It is usually set to fluctuate by one to five percent above or below the target flow rate.

[0050] Furthermore, after determining the lower limit of the effective increment of real-time flow, the fluid control controller calculates the difference between each real-time flow sample value within the pressure pulsation cycle analysis window and the flow value before the cycle.

[0051] When the increase in the real-time traffic sample value relative to the traffic value before the period first reaches the lower limit of the effective increment of real-time traffic, the sampling time at which the lower limit of the effective increment of real-time traffic is first reached is determined as the time when the effective increment of real-time traffic first appears.

[0052] When the increase in all real-time flow sampling values ​​within the pressure pulsation cycle analysis window relative to the flow value before the cycle does not reach the lower limit of the effective increment of real-time flow, the flow occurrence location judgment value is not calculated, and the current pressure pulsation cycle is judged as having no effective increment of real-time flow.

[0053] When the first valid increase in real-time traffic occurs, the location determination value for the traffic occurrence is calculated, expressed as:

[0054] in, This indicates the location where the traffic occurred. This indicates the moment when the effective increase in real-time traffic first occurs. This indicates the time of the lowest pressure sampling within this pressure supply pulsation cycle. This indicates the time of the next lowest pressure sampling within the current pressure pulsation cycle.

[0055] Furthermore, the boundary value at the end of the half-cycle of pressure increase is determined by the following expression:

[0056] in, This indicates the boundary value at the end of half a cycle of pressure increase. This indicates the time of sampling of the highest pressure within this pressure supply pulsation cycle. This indicates the time of the lowest pressure sampling within this pressure supply pulsation cycle. This indicates the time of the next lowest pressure sampling within the current pressure pulsation cycle.

[0057] when At that time, the location where the first effective increase in real-time traffic occurs is determined as half a week of pressure increase; when At that time, the location where the first effective increase in real-time traffic occurs is determined as half a week after the pressure drops.

[0058] The real-time effective increase in flow rate within half a week of pressure increase indicates that the natural pressure supply pulsation can be promptly converted into delivery flow rate; the real-time effective increase in flow rate within half a week of pressure drop indicates that the natural pressure supply pulsation first forms a pressure storage and consumption in the target pipeline, and the delivery flow rate lags behind.

[0059] The fluid control controller reads the maximum increase in the real-time flow rate sample value relative to the flow rate value before the cycle within the pressure pulsation cycle analysis window, and uses this as the maximum increase in real-time flow rate.

[0060] The maximum increase in real-time traffic is expressed as follows:

[0061] in, This indicates the maximum increase in real-time traffic. This indicates the number of cycles within the pressure supply pulsation analysis window. One real-time traffic sampling value, This represents the flow rate value before the period. This indicates the sequence number of the real-time flow sampling value within the pressure pulsation cycle analysis window.

[0062] S3. Based on the correspondence between the first occurrence of the real-time effective flow increment and the pressure rise and fall of half a cycle, determine whether the pressure pulsation is timely converted into the delivery flow, and generate a regulation permission mode that allows pump increase, delayed regulation or pressure reduction protection.

[0063] Furthermore, multi-level judgments are performed to generate adjustment and licensing methods.

[0064] When no effective increase in real-time flow appears in the pressure pulsation cycle analysis window, it indicates that there is already a natural pressure pulsation in the downstream pressure sampling value, but the real-time flow sampling value has not increased to the lower limit of the effective increase in real-time flow, indicating that the pressure change generated by the pump has not been converted into effective delivery flow.

[0065] The fluid control controller sets the regulation permission mode to pressure reduction protection mode, prohibiting the increase of pump speed and avoiding further pressure increase when the target pipeline has not formed an effective delivery flow.

[0066] When the effective increase in real-time flow first appears at half a cycle of pressure drop, it indicates that the natural pressure supply pulsation first forms a pressure storage and consumption in the target pipeline. Although the real-time flow increases, the increase time lags behind the pressure rise by half a cycle.

[0067] The fluid control controller sets the regulation permission mode to delayed regulation mode, prohibits continuous increase of pump speed, and determines the waiting time based on the flow occurrence location judgment value and the pressure rise half-cycle end location boundary value.

[0068] The expression for the waiting time is:

[0069] in, Indicates the waiting time. This indicates the pressure pulsation period. This indicates the location where the traffic occurred. This indicates the boundary value at the end of half a cycle of pressure increase.

[0070] It should be noted that the closer the first occurrence of the effective increase in real-time flow is to the latter half of the pressure drop cycle, the larger the value of the flow occurrence location and the longer the waiting time, so that the target pipeline can complete the release of the transport flow after the pressure is temporarily stored and consumed, and avoid the subsequent flow overshoot caused by the continuous increase of pump speed.

[0071] Furthermore, when the effective increment of real-time flow first appears at half a cycle of pressure increase, it indicates that the natural pressure pulsation has the potential to be converted into delivery flow in a timely manner. The fluid control controller then continues to determine whether the maximum increase in real-time flow is higher than the lower limit of the effective increment of real-time flow.

[0072] If the maximum increase in real-time flow does not exceed the lower limit of the effective increment of real-time flow, it means that the increase in real-time flow has only reached the minimum identifiable boundary and is not enough to support the increase in pump speed. The fluid control controller will determine the regulation permission mode as the delayed regulation mode and reread the downstream pressure sampling value and real-time flow sampling value in the next pressure supply pulsation cycle according to the waiting time.

[0073] If the first occurrence of the effective real-time flow increment occurs during the half-cycle of pressure increase, and the maximum increase in real-time flow exceeds the lower limit of the effective real-time flow increment, it indicates that the natural pressure pulsation can be promptly converted into effective delivery flow during the pressure increase, and the increase in delivery flow exceeds the range covered by stable natural fluctuations. The fluid control controller determines the regulation permission mode as the pump increase regulation mode, and combines the flow occurrence location judgment value, the boundary value of the end position of the half-cycle of pressure increase, the maximum increase in real-time flow, and the lower limit of the effective real-time flow increment to generate the pump speed correction amount.

[0074] Among them, the pressure reduction protection regulation mode is for situations where no effective delivery flow is formed; the delayed regulation mode is for situations where the flow increase is lagging or the flow increase is insufficient; and the pump increase allowance regulation mode is for situations where the pressure pulsation is promptly converted into an effective delivery flow.

[0075] S4. Generate pump speed correction amount, waiting time or pressure reduction direction control amount according to the adjustment permission method, so that the real-time flow of the target pipeline enters the target allowable range and the downstream pressure is lower than the pressure safety boundary.

[0076] When the regulation permission mode is set to allow pump boosting, the fluid regulation controller first calculates the target flow gap coefficient based on the target flow rate and the real-time flow rate at the time of the current control cycle entry judgment. The expression is:

[0077] in, This represents the target flow gap coefficient. Indicates the target traffic. This indicates the real-time flow when the current control cycle enters the judgment phase.

[0078] It should be noted that the target flow gap coefficient is used to indicate the degree to which the real-time flow is lower than the target flow. The larger the target flow gap coefficient, the stronger the demand for pump adjustment in the target pipeline.

[0079] Furthermore, after the target flow gap coefficient is determined, the fluid control controller calculates the pump speed correction based on the target flow gap coefficient, the flow occurrence location judgment value, the boundary value of the end position of the pressure rise half-cycle, the maximum real-time flow increase, and the lower limit of the effective real-time flow increment. The expression is as follows:

[0080] in, This indicates the pump speed correction amount. This indicates the maximum permissible pump speed increment in a single control cycle.

[0081] It should be noted that the maximum allowable pump speed increment per single control cycle is determined by gradually increasing the pump speed during the equipment commissioning phase under the conditions of fixed valve opening and downstream pressure below the pressure safety boundary. The maximum pump speed increase value is selected when the downstream pressure does not exceed the upper limit of stable fluctuation and the real-time flow does not overshoot within adjacent control cycles. It is usually taken as 0.5% to 3% of the rated pump speed.

[0082] It should also be noted that the pump speed correction is calculated only when the first occurrence of the effective increment of real-time flow is located at half a cycle of pressure rise, and the maximum increase in real-time flow is higher than the lower limit of the effective increment of real-time flow.

[0083] The fluid control controller increases the pump speed command according to the pump speed correction amount, while keeping the valve opening command unchanged. If the real-time flow rate is still lower than the target flow rate and the downstream pressure is lower than the pressure safety boundary after the pump speed command is increased, the target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening are reread for the next control cycle. If the real-time flow rate enters the target allowable range, the increased pump speed command is maintained and the current regulation ends.

[0084] When the regulation permission mode is delayed, the fluid regulation controller does not calculate the pump speed correction amount, does not increase the pump speed command, and maintains the current pump speed command and valve opening command during the waiting time.

[0085] After the waiting time ends, the fluid regulation controller rereads the downstream pressure sampling value and real-time flow sampling value within a pressure supply pulsation cycle, and re-executes the determination of the first occurrence position of the pressure rise half cycle, pressure fall half cycle, and real-time flow effective increment, so that the target pipeline releases the transport flow after the pressure temporary storage consumption before entering the next round of judgment.

[0086] When the regulation permission mode is pressure reduction protection regulation mode, the fluid regulation controller prohibits the command to increase the pump speed and performs pressure reduction direction control according to the current valve opening and downstream pressure.

[0087] If the downstream pressure reaches the pressure safety boundary and the current valve opening is higher than the minimum safe opening, the fluid control controller reduces the valve opening according to the maximum permissible valve retraction amount in a single control cycle, thereby reducing the fluid supply to the target pipeline. If the downstream pressure reaches the pressure safety boundary and the current valve opening reaches the minimum safe opening, the fluid control controller reduces the pump speed according to the maximum permissible pump speed reduction amount in a single control cycle, preventing the downstream pressure from continuing to rise. If the downstream pressure does not reach the pressure safety boundary, the pressure reduction direction control amount is zero, the fluid control controller maintains the current pump speed command and valve opening command unchanged, and rereads the downstream pressure sampling value and real-time flow sampling value within the pressure supply pulsation cycle in the next control cycle.

[0088] It should be noted that the minimum safe opening degree is determined by the valve's factory calibration to maintain valve core stability, prevent valve jamming, and maintain the minimum allowable flow capacity, preferably 5% to 15% of the valve's full opening degree. The maximum allowable valve retraction amount per control cycle is determined when the downstream pressure is below the pressure safety boundary, and the difference between the downstream pressure and the pressure safety boundary is not greater than the sum of the pressure sensor's maximum allowable error and control margin. Under the condition of being in the safe approach state and the real-time flow rate being higher than the minimum allowable delivery flow rate, the valve opening degree is gradually reduced, and the actual flow rate is selected. The maximum allowable valve retraction amount per control cycle is the maximum reduction in valve opening when the flow rate is not lower than the minimum allowable delivery flow rate and the fluctuation amplitude of the downstream pressure adjacent sampling does not exceed the sum of the maximum allowable error of the pressure sensor and the control margin. It is preferably taken as 0.5% to 3% of the full valve opening. The maximum allowable pump speed reduction amount per control cycle is determined by gradually reducing the pump speed in the target pipeline under stable delivery conditions during the equipment commissioning stage. The maximum pump speed reduction value is selected when the real-time flow rate does not fall out of the target allowable range and the downstream pressure is not lower than the stable delivery lower limit. It is preferably taken as 0.5% to 3% of the rated pump speed.

[0089] Furthermore, after completing the adjustment of allowing pump increase, delayed adjustment, or pressure reduction protection, the fluid control controller will use the updated pump speed command and valve opening command as the current command for the next control cycle, and re-acquire the target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening until the real-time flow rate enters the target allowable range and the downstream pressure is lower than the pressure safety boundary.

[0090] like Figure 5The diagram illustrates the correspondence between the natural pressure pulsation of downstream pressure and the first occurrence of the effective increase in real-time flow rate within the pressure pulsation cycle. As the curves show, the effective increase occurring within half a week of pressure increase can leave the natural fluctuation range relatively early, indicating that pressure changes can be promptly converted into flow rate, which can serve as a basis for allowing pump increases. The effective increase occurring within half a week of pressure decrease has a significant lag, indicating that pressure changes are first temporarily stored and consumed by the target pipeline, requiring delayed adjustment. If the curve for which no effective flow rate is formed remains close to the stable fluctuation range, pressure reduction protection should be triggered. Figure 5 This invention demonstrates that it can identify timely responses, delayed responses, and ineffective pressure supply by utilizing the pump's natural pressure pulsation without adding extra test and control actions, thus avoiding blindly increasing the pump when the flow rate is low.

[0091] like Figure 6 This paper compares the downstream pressure safety of conventional adaptive pump booster control and the adjustment method of this invention. Conventional adaptive pump booster control tends to continuously increase pump speed when the real-time flow is low, resulting in multiple downstream pressure surges that approach or exceed the pressure safety boundary, indicating insufficient matching between pump speed adjustment and the actual delivery capacity of the target pipeline. The adjustment method of this invention generates a mode that allows pump boosting, delayed adjustment, or pressure reduction protection based on the first occurrence of the effective increase in real-time flow, thus constraining the pump speed correction by the pressure pulsation conversion capability. As shown in the curves, the downstream pressure of the adjustment method of this invention is more stable overall and consistently remains below the pressure safety boundary, reducing the risks of pressure anomalies, flow overshoot, and ineffective energy consumption.

[0092] In summary, this invention utilizes the natural pressure pulsation of the pump to divide the pressure rise and fall into half-cycles, enabling the determination of whether pressure changes are effectively converted into delivery flow without additional testing and control actions. By determining the first occurrence of the effective increase in real-time flow, it distinguishes between timely response, delayed response, and ineffective pressure supply, avoiding blindly increasing the pump when the flow is low. By implementing pump increase, waiting, or pressure reduction protection according to the adjustment permission method, it achieves matching of pump speed regulation with the actual delivery capacity of the pipeline, reducing the risk of pressure anomalies and flow overshoot.

[0093] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A fluid intelligent regulation method based on adaptive control algorithm, characterized in that, include: The system collects the target flow rate, real-time flow rate, downstream pressure, pump speed, and current valve opening of the target pipeline. When the real-time flow rate is lower than the target flow rate and the downstream pressure has not reached the pressure safety boundary, the system determines the pressure pulsation cycle based on the pump speed and reads the pressure and flow rate changes within the cycle while keeping the pump speed command and valve opening command unchanged. Based on the changes in downstream pressure from low to high and from high to low within the pressure pulsation cycle, the pressure pulsation cycle is divided into a pressure rise half-cycle and a pressure fall half-cycle, and the location where the first effective increase in real-time flow is determined is identified. Based on the correspondence between the first occurrence of the real-time effective flow increment and the pressure rise and fall of half a cycle, it is determined whether the pressure pulsation is timely converted into the delivery flow, and an adjustment permission mode is generated that allows for pump increase, delayed adjustment or pressure reduction protection. The pump speed correction amount, waiting time, or pressure reduction direction control amount are generated according to the adjustment permission method, so that the real-time flow of the target pipeline enters the target allowable range and the downstream pressure is lower than the pressure safety boundary.

2. The fluid intelligence regulating method based on adaptive control algorithm as claimed in claim 1 wherein, The pressure safety boundary is determined by subtracting the maximum permissible error of the pressure sensor and the control margin from the allowable downstream pressure of the target pipeline design. The allowable downstream pressure for the target pipeline design includes the minimum permissible pressure among the rated pressures of the target pipeline, joints, seals, and end-use flow equipment; The control margin is determined based on the upper limit of natural downstream pressure fluctuations during the stable delivery phase of the target pipeline.

3. The fluid intelligence regulating method based on adaptive control algorithm as claimed in claim 1 or 2, wherein, The process of determining the pressure pulsation period based on the pump speed includes: The pressure pulsation period is determined based on the number of natural pressure pulsations per pump revolution and the pump speed. The number of natural pressure pulsations is determined according to the pump's discharge structure. For a plunger pump, it is determined by the number of plungers involved in the discharge; for a gear pump, it is determined by the number of times the pump engages and discharges; and for a vane pump, it is determined by the number of times the vanes pass through the discharge zone.

4. The fluid intelligence regulating method based on adaptive control algorithm as claimed in claim 1 wherein, The method of reading pressure and flow rate changes within a cycle while keeping the pump speed command and valve opening command unchanged includes using the pressure pulsation cycle as the reading window, continuously reading the downstream pressure sampling value and real-time flow sampling value within a pressure pulsation cycle, and arranging the downstream pressure sampling value and real-time flow sampling value according to the same time sequence.

5. The fluid intelligence regulating method based on adaptive control algorithm as claimed in claim 4 wherein, The division of the pressure pulsation cycle into a pressure rise half-cycle and a pressure fall half-cycle includes: Within a pressure supply pulsation cycle, determine the lowest pressure sampling time when the downstream pressure changes from decreasing to increasing, the highest pressure sampling time when the downstream pressure changes from increasing to decreasing after the lowest pressure sampling time, and the next lowest pressure sampling time when the downstream pressure changes from decreasing to increasing again after the highest pressure sampling time. The time period between the lowest pressure sampling time and the highest pressure sampling time is defined as the pressure rise half-cycle, and the time period between the highest pressure sampling time and the next lowest pressure sampling time is defined as the pressure fall half-cycle.

6. The fluid intelligent regulation method based on adaptive control algorithm as described in claim 5, characterized in that, The determination of the first occurrence position of the effective real-time traffic increment includes: The real-time flow rate value at the sampling moment before entering the pressure pulsation cycle is taken as the flow rate value before the cycle. The lower limit of the effective increment of real-time flow is determined based on the minimum resolution of the flow meter and the upper limit of the absolute value of the flow change between adjacent samples during the stable operation phase of the target pipeline. The difference between each real-time flow sampling value within the pressure pulsation cycle and the flow value before the cycle is calculated. When the difference first reaches the lower limit of the effective increment of real-time flow, the corresponding sampling time is determined as the time when the effective increment of real-time flow first appears. If the increase in each real-time flow sample value relative to the flow value before the cycle does not reach the lower limit of the effective increase in real-time flow within the pressure supply pulsation cycle, it is determined that there is no effective increase in real-time flow in this pressure supply pulsation cycle.

7. The fluid intelligent regulation method based on adaptive control algorithm as described in claim 6, characterized in that, The determination of the first occurrence position of the effective real-time traffic increment includes: When there is a moment when the effective increment of real-time traffic first appears, the traffic occurrence location judgment value is determined based on the moment when the effective increment of real-time traffic first appears, the moment when the lowest pressure is sampled, and the moment when the next lowest pressure is sampled. The boundary value at the end of the half-cycle of pressure rise is determined based on the sampling time of the highest pressure, the sampling time of the lowest pressure, and the sampling time of the next lowest pressure. When the location value of the flow rate occurrence is not greater than the boundary value of the end of the half-cycle of pressure rise, the location of the first occurrence of the effective increase in real-time flow rate is determined as the half-cycle of pressure rise. When the location value of the flow rate is greater than the boundary value of the end of the half-cycle of pressure rise, the location of the first occurrence of the effective increase in real-time flow rate is determined as the half-cycle of pressure fall.

8. The fluid intelligent regulation method based on adaptive control algorithm as described in claim 7, characterized in that, The regulation permission methods for generating pump boosting, delayed regulation, or pressure reduction protection include: When no effective increase in real-time flow occurs during the current pressure pulsation cycle, the adjustment permission mode will be set to the pressure reduction protection adjustment mode. When the first effective increase in real-time flow occurs at a point halfway down the pressure cycle, the adjustment permission method will be determined as a delayed adjustment method. When the effective increment of real-time flow first appears at half a cycle of pressure rise, the maximum increase of the real-time flow sample value relative to the flow value before the cycle is further determined within the pressure pulsation cycle. If the maximum increase is not higher than the lower limit of the effective increment of real-time flow, the adjustment permission mode is determined to be the delayed adjustment mode. If the maximum increase is higher than the lower limit of the effective increment of real-time flow, the adjustment permission mode is determined to be the pump increase adjustment mode.

9. The fluid intelligent regulation method based on adaptive control algorithm as described in claim 8, characterized in that, The method of generating the pump speed correction amount according to the adjustment permission method includes: When the adjustment permission mode is the pump increase adjustment mode, the target flow gap coefficient is determined based on the target flow and the real-time flow at the time of the current control cycle entry judgment. Based on the target flow gap coefficient, the flow occurrence location judgment value, the boundary value of the end of the half-cycle of pressure rise, the maximum increase in real-time flow, and the lower limit of the effective increment of real-time flow, the pump speed correction amount is generated. The pump speed correction amount includes a pump speed correction amount that is not greater than the maximum allowable pump speed increment in a single control cycle, and the pump speed correction amount is generated only when the first occurrence of the effective increment of real-time flow is located at half a cycle of pressure rise and the maximum increase in real-time flow is higher than the lower limit of the effective increment of real-time flow.

10. The fluid intelligent regulation method based on adaptive control algorithm as described in claim 8 or 9, characterized in that, The method of generating the waiting time or voltage reduction direction control quantity according to the adjustment permission method includes: When the adjustment permission method is the delayed adjustment method, the waiting time is determined based on the pressure pulsation cycle, the flow occurrence location judgment value, and the boundary value of the end position of the pressure rise half cycle. During the waiting period, maintain the current pump speed command and the current valve opening command unchanged; When the regulation permission mode is pressure reduction protection regulation mode, the command to increase pump speed is prohibited, and the pressure reduction direction control quantity is generated according to the current valve opening and downstream pressure; If the downstream pressure reaches the pressure safety boundary and the current valve opening is higher than the minimum safe opening, then the pressure reduction direction control amount is the valve opening retraction amount; If the valve's current opening has reached the minimum safe opening, then the pressure reduction direction control amount is the amount of pump speed reduction.

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