Automatic flow compensation control method and system for digital metering pump

Abstract

The invention provides an automatic flow compensation control method and system for a digital metering pump, and relates to the technical field of digital metering pumps. The actual flow is monitored in real time through the built-in flowmeter, the difference value between the actual flow and the set value is calculated, the compensation coefficient is dynamically adjusted, complete closed-loop feedback control is formed, it is ensured that the flow deviation is controlled within the allowable error range, and the problem of flow attenuation caused by inlet air leakage, valve foreign matter, valve seat abrasion and the like is effectively solved; the high-precision flow control requirement is met, when non-fatal hardware faults (such as partial blockage and slight abrasion) occur in equipment, shutdown maintenance is not needed, flow output is maintained through automatic compensation, the continuity of the production process is guaranteed, and production interruption loss caused by the faults is reduced.

Description

Technical Field

[0001] This invention relates to the field of digital metering pump technology, and more specifically, to an automatic flow compensation control method and system for digital metering pumps. Background Technology

[0002] In industrial production and various fluid transportation scenarios, metering pumps are core equipment for precise flow control. Their operational stability and flow output accuracy directly affect the reliability of production processes and product quality. In actual applications, digital metering pumps are prone to various abnormal situations that lead to flow attenuation due to complex working conditions. These include inlet air leakage but not complete failure and water output, outlet valve blockage by foreign objects but not complete blockage, and decreased sealing performance of valve ball and valve seat due to long-term wear. Most existing metering pump technologies lack the ability to automatically sense and compensate for flow rate decline. When such flow anomalies occur, manual detection and adjustment of equipment parameters are required to restore the set flow rate. This is not only cumbersome and slow to respond, but may also affect production efficiency due to persistent flow deviations. Some devices with flow regulation functions only use a simple open-loop control method, failing to form a complete monitoring-feedback-compensation closed loop, and do not consider the problem of mis-adjustment caused by short-term flow fluctuations. Therefore, we propose an improvement: an automatic flow compensation control method and system for digital metering pumps. Summary of the Invention

[0003] This invention provides an automatic flow compensation control method for a digital metering pump, comprising the following steps: S1. Flow monitoring and comparison: Obtain the actual flow rate Q_actual of the metering pump through the built-in flow meter, and calculate the flow difference ΔQ=Q_set-Q_actual; S2. Judgment and Timing: Determine if ΔQ > 0. If ΔQ > 0, start the timer and determine if the timing time T ≥ n seconds. If so, determine that the flow is abnormal and enter the compensation process. If ΔQ ≤ 0, maintain the current running state. S3. Flow compensation calculation: Calculate the compensation coefficient K=ΔQ / Q_set based on the flow difference, and calculate the target rotational speed N_new=N_current×(1+α×K); S4. Safety Limit Check: Determine whether the target speed N_new is less than or equal to the maximum motor speed N_max and whether the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max. If both conditions are met, perform compensation and adjust the motor speed to N_new. If not, trigger the protection mechanism.

[0004] As a preferred technical solution of this application, before real-time flow monitoring, the system parameters are initialized, including: reading the customer-set flow value Q_set, setting the compensation delay time n seconds and the maximum flow rate Q_max of the digital metering pump.

[0005] As a preferred technical solution of this application, in S2, if it is determined whether the timing time T is ≥ n seconds, the counter is reset and the detection continues if not.

[0006] As a preferred technical solution of this application, in S3, when calculating the target speed N_new, it is based on the current motor speed N_current, the compensation coefficient K, and the compensation gain coefficient α.

[0007] As a preferred technical solution in this application, in S3, the triggered protection mechanism is to output an alarm and maintain the maximum safe operating capability of the equipment.

[0008] As a preferred technical solution of this application, the alarm method when outputting an alarm is to output an audible and visual alarm signal and send a fault prompt message to the control terminal.

[0009] As a preferred technical solution of this application, in S4, during the safety limit check, the maximum speed of the motor N_max and the maximum flow rate of the pump Q_max are the rated parameters of the equipment, which are pre-entered and stored through system initialization.

[0010] As a preferred technical solution of this application, it also includes S5, compensation verification and loop: after performing compensation, wait for m seconds for verification cycle, re-monitor the actual flow rate and calculate the new difference ΔQ_new. If |ΔQ_new| < allowable error ε, the compensation is completed and the current speed is maintained; otherwise, return to S2 to continue the cyclic compensation.

[0011] An automatic flow compensation control system for a digital metering pump, used to implement an automatic flow compensation control method for a digital metering pump, includes: Flow monitoring module: Employs a built-in flow meter to monitor the actual flow rate of the digital metering pump in real time and obtain the actual flow rate value Q_actual; The comparison and judgment module is used to calculate the flow difference ΔQ=Q_set-Q_actual, determine whether ΔQ is greater than 0, and also to calculate the new difference ΔQ_new in the compensation verification stage and determine whether |ΔQ_new| is less than the allowable error ε. Timer module: Used to start timing when ΔQ>0, record timing time T, and reset the timer when timing time T is less than n seconds; The compensation calculation module is used to calculate the compensation coefficient K=ΔQ / Q_set based on the flow difference ΔQ, and then calculate the target speed N_new=N_current×(1+α×K) based on the current motor speed N_current, the compensation coefficient K and the compensation gain coefficient α. Safety check module: Used to determine whether the target speed N_new is less than or equal to the maximum motor speed N_max and whether the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max, and outputs the check results; Execution module: Used to receive the pass command from the safety check module, execute the motor speed adjustment operation, and adjust the motor speed to the target speed N_new; also used to receive the fail command from the safety check module and trigger the protection mechanism; Verification module: Used to set the verification period m seconds. After compensation is performed, wait for the m-second verification period, control the traffic monitoring module to re-monitor the actual traffic, and cooperate with the comparison and judgment module to complete the evaluation of the compensation effect.

[0012] As a preferred technical solution of this application, it also includes a human-computer interaction module for users to input or modify parameters.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: In the scheme of this application: 1. This application monitors the actual flow rate in real time through a built-in flow meter, calculates the difference between the actual flow rate and the set value, and dynamically adjusts the compensation coefficient to form a complete closed-loop feedback control. This ensures that the flow deviation is controlled within the allowable error range, effectively solving the flow attenuation problem caused by inlet leakage, foreign objects in the valve, and valve seat wear, meeting the requirements of high-precision flow control. When the equipment experiences non-fatal hardware failures (such as partial blockage or slight wear), there is no need to stop the machine for maintenance. The flow output is maintained through automatic compensation, ensuring the continuity of the production process and reducing production interruption losses caused by failures. 2. The entire process of traffic monitoring, anomaly detection, compensation calculation and execution is automated without human intervention, avoiding the cumbersome process of traditional manual adjustment, reducing labor costs, shortening traffic recovery response time, and improving overall production efficiency. Attached Figure Description

[0014] Figure 1 A flowchart of the automatic flow compensation control method for digital metering pumps provided in this application; Figure 2 A schematic diagram illustrating the parameters, symbols, and descriptions provided in this application; Figure 3 A cross-sectional view of the digital metering pump provided in this application. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0016] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0018] Example 1, please refer to Figure 1 An automatic flow compensation control method for a digital metering pump includes the following steps: Initialize system parameters, including: reading the customer-set flow rate value Q_set, setting the compensation delay time n seconds and the maximum flow rate Q_max of the digital metering pump; parameter initialization is the preliminary step of the automatic control process. Setting the flow rate value clarifies the control target, the compensation delay time defines the abnormal judgment standard, and the maximum flow rate defines the operating limit. The three together constitute the basic framework for stable system operation. S1. Flow monitoring and comparison: The actual flow rate Q_actual of the metering pump is obtained through the built-in flow meter, and the flow difference ΔQ=Q_set-Q_actual is calculated; the actual flow rate and the set flow rate are accurately compared, the flow deviation is quickly located, and the basis for judgment on whether to start the compensation process is provided to ensure the targeted nature of flow control. S2. Judgment and Timing: Determine if ΔQ > 0. If ΔQ ≤ 0, maintain the current operating state. If ΔQ > 0, start the timer and determine if the timing time T ≥ n seconds. If yes, it is determined to be an abnormal flow rate, and the compensation process is initiated. If not, the counter is reset, and the detection continues. Instantaneous flow rate fluctuations are normal operating conditions. By setting a compensation delay time of n seconds and timing the judgment, short-term fluctuation interference can be filtered out, preventing frequent compensation from causing frequent changes in motor speed and increased wear of components. When the flow rate deviation continues to exceed n seconds, it is determined to be a real abnormality and compensation is initiated, which can correct the flow rate deviation in a timely manner and avoid the deviation from expanding and affecting the metering accuracy. S3. Flow Compensation Calculation: The compensation coefficient K = ΔQ / Q_set is calculated based on the flow difference. The target speed N_new = N_current × (1 + α × K) is calculated based on the current motor speed N_current, the compensation coefficient K, and the compensation gain coefficient α. The compensation coefficient K is calculated by the ratio of the flow difference to the set flow, which reflects the relative degree of flow deviation rather than the absolute value, making the compensation strategy more in line with the actual working conditions. The compensation gain coefficient α can be introduced to flexibly adjust the compensation intensity and adapt to the flow requirements under different media and working conditions. The target speed calculation formula is derived based on the current operating state to ensure that the adjusted speed can specifically compensate for the flow deviation, taking into account both compensation speed and stability. S4. Safety Limit Check: Determine if the target speed N_new is less than or equal to the maximum motor speed N_max and if the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max. If both conditions are met, compensation is performed to adjust the motor speed to N_new. If not, a protection mechanism is triggered. The triggered protection mechanism is to output an alarm and maintain the equipment's maximum safe operating capacity. The alarm method when outputting an alarm is to output an audible and visual alarm signal and send a fault prompt message to the control terminal. The maximum motor speed and the maximum pump flow rate are the rated parameters of the equipment. Exceeding the rated values ​​will lead to accelerated wear of components, shortened service life, and even safety accidents. Dual safety judgment can avoid risks from two core dimensions: speed and flow rate. The audible and visual alarm can remind the staff on-site, while the remote fault prompt facilitates real-time monitoring in the background and enables rapid fault response. At the same time, maintaining the maximum safe operating capacity can avoid production interruptions caused by sudden equipment shutdown. During safety limit checks, the maximum motor speed N_max and the maximum pump flow rate Q_max are the equipment's rated parameters, which are pre-entered and stored during system initialization. The equipment's rated parameters are the safe operating limits verified by the manufacturer. Pre-entering and storing them can avoid signal interference or delays during real-time reading. At the same time, fixing the parameter values ​​can ensure that the judgment criteria for each safety check are consistent, preventing false triggering or missed triggering of the safety protection mechanism due to parameter fluctuations, and providing a stable guarantee for the safe operation of the equipment. It also includes S5, compensation verification and loop: After compensation is performed, wait for an m-second verification cycle, then re-monitor the actual flow rate and calculate the new difference ΔQ_new. If |ΔQ_new| < allowable error ε, the compensation is complete and the current speed is maintained; otherwise, return to S2 to continue the cyclic compensation. After the compensation operation, there may be flow rebound or insufficient adjustment. The m-second verification cycle can provide time for flow stabilization and avoid misjudgment of results caused by immediate detection. The allowable error ε defines the qualified flow control range, which meets the actual production requirements for metering accuracy. Parameters, symbols, and descriptions are as follows: Figure 2 As shown.

[0019] Example 2. An automatic flow compensation control system for implementing an automatic flow compensation control method for a digital metering pump, comprising: Initialization module: used to read the customer-set flow rate value Q_set, set the compensation delay time n seconds and the maximum flow rate Q_max of the digital metering pump, and pre-enter and store the maximum motor speed N_max and the maximum pump flow rate Q_max; Flow monitoring module: It adopts a built-in flow meter to monitor the actual flow of the digital metering pump in real time and obtain the actual flow value Q_actual; it realizes real-time and accurate acquisition of flow data, provides high-quality data input for the comparison and judgment module and the compensation calculation module, and ensures the reliability of the decision basis of the entire control process; The comparison and judgment module is used to calculate the flow difference ΔQ=Q_set-Q_actual, determine whether ΔQ is greater than 0, and also to calculate the new difference ΔQ_new in the compensation verification stage and determine whether |ΔQ_new| is less than the allowable error ε. Timer module: Used to start timing when ΔQ>0, record timing time T, and reset the timer when timing time T is less than n seconds; The compensation calculation module is used to calculate the compensation coefficient K=ΔQ / Q_set based on the flow difference ΔQ, and then calculate the target speed N_new=N_current×(1+α×K) based on the current motor speed N_current, the compensation coefficient K and the compensation gain coefficient α. Safety check module: Used to determine whether the target speed N_new is less than or equal to the maximum motor speed N_max and whether the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max, and outputs the check results; Execution module: Used to receive the pass command from the safety check module, execute the motor speed adjustment operation, and adjust the motor speed to the target speed N_new; also used to receive the fail command from the safety check module and trigger the protection mechanism; Verification module: Used to set the verification period m seconds. After compensation is performed, wait for the m-second verification period, control the traffic monitoring module to re-monitor the actual traffic, and cooperate with the comparison and judgment module to complete the evaluation of the compensation effect.

[0020] The built-in flow meter and digital metering pump are integrated into one design to ensure real-time and accurate flow monitoring; The protection mechanisms triggered by the execution module include outputting alarms and maintaining the equipment's maximum safe operating capability; It also includes a storage module for storing data, where the stored data includes customer-set flow value Q_set, compensation delay time n seconds, maximum flow Q_max, maximum motor speed N_max, compensation gain coefficient α, verification period m seconds, allowable error ε parameter information, as well as flow monitoring data, calculation data, and judgment results; The motor mentioned above is the motor of a digital metering pump.

[0021] It also includes a human-machine interaction module for allowing users to input or modify parameters, including parameters such as set flow value Q_set, compensation delay time n seconds, compensation gain coefficient α, verification period m seconds, allowable error ε, and is also used to display the device operation status, flow data, and alarm information.

[0022] Refer Figure 3 , Figure 3 is a cross-sectional structure diagram of the digital metering pump provided by this application, Figure 3 At AA in it is marked as a flowmeter, at BB is marked as the main control board, at CC is marked as the motor of the digital metering pump, the arrow indicates the medium flow direction, and the automatic flow compensation control system is integrated on the main control board.

[0023] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.[[ID=~16]]

[0024] Obviously, the embodiments described above are only a part of the embodiments of the present invention, rather than all embodiments. The drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements on some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present invention in other related technical fields is equally within the scope of the patent protection of the present invention.

Claims

1. A digital metering pump automatic flow compensation control method, characterized in that, Includes the following steps: S1. Flow monitoring and comparison: Obtain the actual flow rate Q_actual of the metering pump through the built-in flow meter, and calculate the flow difference ΔQ=Q_set-Q_actual; S2. Judgment and Timing: Determine if ΔQ > 0. If ΔQ > 0, start the timer and determine if the timing time T ≥ n seconds. If so, determine that the flow is abnormal and enter the compensation process. If ΔQ ≤ 0, maintain the current running state. S3. Flow compensation calculation: Calculate the compensation coefficient K=ΔQ / Q_set based on the flow difference, and calculate the target rotational speed N_new=N_current×(1+α×K); S4. Safety Limit Check: Determine whether the target speed N_new is less than or equal to the maximum motor speed N_max and whether the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max. If both conditions are met, perform compensation and adjust the motor speed to N_new. If not, trigger the protection mechanism.

2. The digital metering pump automatic flow compensation control method of claim 1, wherein, Before real-time flow monitoring, the system parameters are initialized, including: reading the customer-set flow value Q_set, setting the compensation delay time n seconds, and the maximum flow rate Q_max of the digital metering pump.

3. The automatic flow compensation control method for digital metering pumps according to claim 1, characterized in that, In S2, if the timing time T is ≥ n seconds, and if not, the counter is reset and the detection continues.

4. The automatic flow compensation control method for digital metering pumps according to claim 1, characterized in that, In S3, when calculating the target speed N_new, it is based on the current motor speed N_current, the compensation coefficient K, and the compensation gain coefficient α.

5. The automatic flow compensation control method for a digital metering pump according to claim 1, characterized in that, In S3, the triggered protection mechanism is to output an alarm and maintain the equipment's maximum safe operating capability.

6. The automatic flow compensation control method for digital metering pumps according to claim 1, characterized in that, When an alarm is output, the alarm method is to output an audible and visual alarm signal and send a fault prompt message to the control terminal.

7. The automatic flow compensation control method for a digital metering pump according to claim 1, characterized in that, In S4, during the safety limit check, the maximum motor speed N_max and the maximum pump flow rate Q_max are the rated parameters of the equipment, which are pre-entered and stored through system initialization.

8. The automatic flow compensation control method for a digital metering pump according to claim 1, characterized in that, It also includes S5, compensation verification and loop: After performing compensation, wait for m seconds for verification cycle, re-monitor the actual flow and calculate the new difference ΔQ_new. If |ΔQ_new| < allowable error ε, the compensation is completed and the current speed is maintained; otherwise, return to S2 to continue the loop compensation.

9. A digital metering pump automatic flow compensation control system, used to implement the digital metering pump automatic flow compensation control method according to any one of claims 2-7, characterized in that, include: Flow monitoring module: Employs a built-in flow meter to monitor the actual flow rate of the digital metering pump in real time and obtain the actual flow rate value Q_actual; The comparison and judgment module is used to calculate the flow difference ΔQ=Q_set-Q_actual, determine whether ΔQ is greater than 0, and also to calculate the new difference ΔQ_new in the compensation verification stage and determine whether |ΔQ_new| is less than the allowable error ε. Timer module: Used to start timing when ΔQ>0, record timing time T, and reset the timer when timing time T is less than n seconds; The compensation calculation module is used to calculate the compensation coefficient K=ΔQ / Q_set based on the flow difference ΔQ, and then calculate the target speed N_new=N_current×(1+α×K) based on the current motor speed N_current, the compensation coefficient K and the compensation gain coefficient α. Safety check module: Used to determine whether the target speed N_new is less than or equal to the maximum motor speed N_max and whether the compensated actual flow rate Q_actual_new is less than or equal to the maximum flow rate Q_max, and outputs the check results; Execution module: Used to receive the pass command from the safety check module, execute the motor speed adjustment operation, and adjust the motor speed to the target speed N_new; It is also used to receive failure instructions from the security check module and trigger the protection mechanism; Verification module: Used to set the verification period m seconds. After compensation is performed, wait for the m-second verification period, control the traffic monitoring module to re-monitor the actual traffic, and cooperate with the comparison and judgment module to complete the evaluation of the compensation effect.

10. The automatic flow compensation control system for digital metering pumps according to claim 9, characterized in that, It also includes a human-computer interaction module, which allows users to input or modify parameters.

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