Method for realizing frequency conversion flow control of acid regeneration mud pump

Abstract

The application discloses an acid regeneration mud pump variable frequency flow control implementation method, comprising the following steps: S1, mud pump speed basic adjustment; S2, data acquisition; S3, building mud viscosity-working condition parameter correlation compensation model; S4, dynamic adaptive adjustment of mud pump speed; S5, alarm program setting. The acid regeneration mud pump variable frequency flow control implementation method completely solves the flow pressure uncontrollable problem caused by the existing pneumatic and time control, on the one hand, avoids the equipment load mutation caused by pneumatic and time control, on the other hand, through dynamic compensation, the mud pump speed and the conveying resistance are matched, the hidden loss caused by local load fluctuation is eliminated, the service life of the mud pump and the pipeline accessories is prolonged, only the concentration and temperature sensors need to be added, without adding large hardware equipment, the compensation model and the control logic are directly debugged and deployed in the PLC control system of the existing acid regeneration production line, and the transformation cost is low and the construction period is short.

Description

Technical Field

[0001] This invention relates to the field of acid regeneration process technology, specifically to a method for implementing variable frequency flow control of acid regeneration mud pumps. Background Technology

[0002] In the acid regeneration process of the metallurgical industry, the mud pump is the core equipment of the desiliconization process. The stability of its conveying flow rate and pressure directly determines the desiliconization production efficiency, the product quality of iron oxide powder and mud cake, and also affects the operating status of subsequent equipment such as roasting furnace, acid gun nozzle, and negative pressure fan. Currently, there are two main methods for driving and controlling mud pumps: one is the constant-speed pneumatic drive method, which cannot accurately control the flow rate and pressure of the mud, resulting in unstable production efficiency of acid regeneration and desilication, large fluctuations in the quality of iron oxide powder, and the acid gun nozzle is prone to clogging due to uneven flow and pressure, causing the power of the pump supplied to the roasting furnace to be too high and shortening the service life of the equipment; the other is the time control method, which cannot adjust the flow rate according to the actual process requirements, making it difficult to control the quality of the mud cake, and is prone to sudden changes in the load of the mud pump, accelerating equipment damage. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for implementing variable frequency flow control of acid regeneration mud pumps, thus solving the problems mentioned in the background section.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for frequency conversion flow control of an acid regeneration mud pump, comprising the following steps: S1. Basic adjustment of mud pump speed: A basic architecture for variable frequency speed control of mud pumps is established. The controller connects the frequency converter to the variable frequency motor of the mud pump. The controller pre-stores the baseline flow rate data of mud delivery. The frequency converter receives the frequency adjustment signal from the controller and drives the variable frequency motor to change its speed, thereby realizing the basic adjustment of the mud pump speed. S2, Data Acquisition: Concentration and temperature sensors are installed at the mud pump feed line to collect the actual concentration value of the mud in the acid regeneration process in real time. Actual temperature value The acquired analog signal is transmitted to the analog input unit of the flow control program, and compared with the actual mud flow value acquired by the flow detection module. Synchronous storage; S3. Construct a mud viscosity-operating condition parameter correlation compensation model: A mud viscosity-operating condition parameter correlation compensation model is constructed in the flow control program. Based on the process characteristics of acid regeneration mud, a viscosity calculation formula and a flow compensation coefficient calculation formula are preset, and the data is collected in real time. , Calculate the actual viscosity value of the mud. Then through The flow compensation coefficient is derived. ; S4. Dynamic adaptation and adjustment of mud pump speed: The controller will store the pre-stored baseline flow value With flow compensation coefficient The calculation is performed to obtain a dynamic target flow rate value that is adapted to the current mud working conditions. ,by The output frequency of the frequency converter is adjusted based on the reference to achieve dynamic adaptation and adjustment of the mud pump speed; S5. Alarm Program Settings: The actual concentration value of the mud Actual temperature value Actual viscosity value The flow alarm program is incorporated, and alarm logic for exceeding the threshold of operating parameters is set. The alarm signal is transmitted to the field control box and triggers the fault alarm indicator light. At the same time, when the parameter exceeds the threshold, the inverter frequency reduction or shutdown protection signal is output.

[0005] Furthermore, the viscosity calculation formula of the mud viscosity-operating condition parameter correlation compensation model in step S3 is as follows:

[0006] in, This is the reference viscosity value for the mud. This is the baseline concentration value for the mud. This is the reference temperature value for the mud. This is the coefficient of influence of concentration and viscosity. This is the coefficient for the effect of temperature on viscosity. The range of values ​​is , The range of values ​​is .

[0007] Furthermore, the formula for calculating the flow compensation coefficient in step S3 is:

[0008] when At that time, take ;when At that time, take ;when When taking the actual calculated value, use the actual value.

[0009] Furthermore, the dynamic target flow value in step S4 The calculation formula is:

[0010] The controller will collect the actual flow rate of the mud in real time. and In contrast, when At that time, the controller sends a frequency adjustment signal to the inverter until... .

[0011] Furthermore, the variable frequency speed control infrastructure in step S1 includes a variable frequency power supply control module, a cooling fan operation control module, a variable frequency motor operation control module, and a field operation box control module. Each module achieves logical linkage through program segments. The cooling fan operation control includes local and remote dual modes. The variable frequency motor operation control must meet the prerequisite of normal operation of the cooling fan and no fault signals.

[0012] Furthermore, the threshold for the alarm of exceeding the threshold operating condition parameter in step S5 is: concentration threshold. , Temperature threshold , Viscosity threshold , .

[0013] Furthermore, when , , , , , If any one of the following conditions is met, an operating condition parameter warning is triggered; if two or more conditions are met, the inverter frequency reduction protection is triggered. When this occurs, the inverter shutdown protection is triggered.

[0014] Furthermore, in step S2, the concentration sensor is an online mud concentration meter, and the temperature sensor is a platinum resistance temperature sensor. The signal output type of both is a 4~20mA analog signal, which is matched with the analog input unit of the flow control program.

[0015] Furthermore, the flow alarm program includes flow scaling transformation, flow dead zone setting, high-high and low-low flow alarm logic, and high-high flow alarm value. Low flow alarm value Alarm dead zone set .

[0016] This invention provides a method for implementing variable frequency flow control of acid regeneration mud pumps, which has the following beneficial effects: 1. This method for implementing variable frequency flow control of acid regeneration slurry pump completely solves the problem of uncontrollable flow and pressure caused by existing pneumatic and time-based control. At the same time, it makes up for the working condition adaptation defects of existing variable frequency fixed value control. Through a dynamic compensation model, it achieves high-precision control of slurry pump flow, ensuring stable reaction conditions in the acid regeneration desilication process and fundamentally solving the problem of unstable desilication production efficiency.

[0017] 2. This variable frequency flow control method for acid regeneration slurry pumps avoids sudden changes in equipment load caused by pneumatic and time-based control. Furthermore, it dynamically compensates to match the pump speed with the conveying resistance, eliminating hidden losses caused by local load fluctuations. This extends the service life of the slurry pump and pipeline fittings. Only concentration and temperature sensors need to be added, eliminating the need for new large hardware equipment. The compensation model and control logic are implemented through program segment expansion, allowing for direct debugging and deployment in the existing PLC control system of the acid regeneration production line. This method offers low modification costs, short construction periods, and is suitable for slurry pump modifications in acid regeneration production lines across various metallurgical industries. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the steps in the method for implementing variable frequency flow control of acid regeneration mud pump according to the present invention. Detailed Implementation

[0019] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0020] like Figure 1 As shown, the present invention provides a technical solution: a method for implementing variable frequency flow control of an acid regeneration mud pump, comprising the following steps: S1: Construct a basic variable frequency speed control architecture consisting of a controller, frequency converter, variable frequency motor, and mud pump. The controller is a PLC programmable logic controller, which pre-stores the mud reference flow rate value required for the acid regeneration and desilication process. The frequency converter is connected to the controller via a communication module, receives the frequency adjustment signal from the controller, and drives the variable frequency motor of the mud pump to change the speed, thereby adjusting the delivery flow of the mud pump. This infrastructure comprises four core control modules, each implementing its function through independent program segments to ensure stable system operation: Inverter power control: Implements power-on and power-off logic control of the inverter, and sets the preconditions for power-on to be that the cooling fan power supply, motor power supply, and signal power supply are normal and there are no fault signals. Cooling fan operation control: Designed with local and remote dual operation modes to meet the needs of on-site commissioning and remote operation from the central control unit. Normal operation of the fan is a prerequisite for the operation of the variable frequency motor. Variable frequency motor operation control: Integrates local or remote operation or stop signals, process permission signals, and fault signals. The motor can only receive operation signals under the premise of no fault, process permission, and normal operation of the cooling fan. On-site control box: Enables on-site start / stop of the frequency converter system, displays fault alarms, and provides real-time feedback of fault signals to the controller for easy on-site operation and maintenance; S2: Install an online mud concentration meter and a platinum resistance temperature sensor at key locations in the mud pump feed pipeline (1-2m from the pump body to avoid pump vibration affecting detection accuracy) to collect the actual mud concentration value in real time. (Unit: %) Actual temperature value (Unit: °C); Simultaneously, a flow detection module is installed in the mud pump discharge pipeline to collect the actual mud flow rate. (unit: ); The concentration and temperature sensors output 4-20mA analog signals, which are matched with the analog input unit of the flow control program to acquire the signals. , After the signal is converted from analog to digital, it is... The data is synchronously transmitted to the controller's storage unit at a sampling frequency of 1 time per second to ensure the real-time performance of operating parameters. S3: A new subroutine for the mud viscosity-operating condition parameter correlation compensation model has been added to the flow control program. This subroutine is based on the physical properties of acid regeneration mud and the actual process. It presets the viscosity calculation formula and the flow compensation coefficient calculation formula to realize the automatic derivation from operating condition parameters to compensation coefficients. The specific formulas and parameter descriptions are as follows: Viscosity calculation formula:

[0021] in, This is the reference viscosity value for the mud. The reference mud concentration value is determined based on the on-site process calibration, and is typically taken as [value missing]. ; The reference temperature value for the mud is determined based on the on-site process calibration, and is typically taken as [value missing]. ; This is the coefficient of influence of concentration and viscosity. The range of values ​​is This characterizes the viscosity change corresponding to a 1% change in mud concentration, and is calibrated by on-site process tests. This is the coefficient for the effect of temperature on viscosity. The range of values ​​is This characterizes the proportion of viscosity change corresponding to a 1°C change in mud temperature, and is calibrated by field process tests. Formula for calculating flow compensation coefficient:

[0022] To avoid sudden frequency changes in the inverter caused by excessively large or small compensation coefficients, the following measures are taken: Apply threshold limits: when At that time, take ;when At that time, take ;when When taking the actual calculated value; This is the flow compensation coefficient. hour This indicates that the viscosity of the mud has increased, the conveying resistance has increased, and the frequency of the frequency converter needs to be increased to compensate for the flow rate. hour This indicates that the slurry viscosity has decreased and the conveying resistance has decreased, so the frequency of the inverter needs to be reduced to avoid excessive flow. S4: The controller retrieves the real-time calculated flow compensation coefficient from the storage unit. Compared with the pre-stored baseline flow value Perform calculations to obtain the dynamic target flow value. The calculation formula is:

[0023] The controller will collect the actual flow rate value from the flow detection module. With dynamic target flow value Perform real-time comparison and set the flow control precision to... ,when At this time, the controller sends a frequency adjustment signal to the frequency converter. Based on the direction of the deviation, the controller sends a frequency up or down signal to the frequency converter, and the frequency converter gradually adjusts the output frequency (each adjustment increment). Until This enables adaptive and precise control of the mud pump flow rate; S5: The actual mud concentration value Actual temperature value Actual viscosity value The flow alarm program will be integrated, and the baseline value for the flow alarm will be changed from the original preset value to a dynamic target flow value. : High flow alarm value:

[0024] Low flow alarm values:

[0025] Alarm dead zone setting To avoid frequent alarms caused by small fluctuations in traffic; Upper and lower thresholds of preset operating parameters (based on baseline calibration): Concentration threshold , Temperature threshold , Viscosity threshold , ;when , , When any of the above conditions exceed the threshold, the controller sends a warning signal to the field control box, triggering a yellow fault alarm light to remind maintenance personnel to investigate process problems; when , , When two or more parameters exceed the threshold, the controller sends a frequency reduction signal to the frequency converter, reducing the frequency converter's output frequency to 80% of the rated frequency, while continuously collecting parameters until the parameters return to normal; when the actual viscosity value of the mud... When the mud viscosity exceeds the mud pump's compatibility range, the controller sends a shutdown signal to the frequency converter and triggers the red fault alarm light to prevent the mud pump from being overloaded and damaged. Furthermore, all alarm signals and protection actions will be logged in the controller, including the time when the parameter exceeded the standard, the value, and the type of protection action, which will facilitate subsequent process analysis and equipment operation and maintenance. Example: The rated flow rate of the mud pump in the acid regeneration production line of a metallurgical enterprise is... The rated speed is 1450 r / min, the matching frequency converter is a 37kW general-purpose frequency converter, and the controller is an S7-300 PLC. The basic parameters are calibrated according to the on-site process. , , , , Baseline flow rate ; Build a variable frequency speed control architecture for PLC controller, frequency converter, variable frequency motor, and mud pump; write and debug program segments for frequency converter power control, cooling fan operation control, variable frequency motor operation control, and field control box control; set the cooling fan to remote mode and link it with the central control system; after debugging, set the reference flow value... Pre-stored to the PLC controller; An online mud concentration meter (with high accuracy) is installed 1.5m from the pump body on the mud pump feed pipe. ) and platinum resistance temperature sensor (detection accuracy) Install an electromagnetic flow meter on the discharge pipeline (detection accuracy) Connect the 4~20mA analog signals from the three sensors to the analog input module of the PLC to complete the signal conversion and debugging, and set the acquisition frequency to 1 time / second; Write a subroutine for the mud viscosity-operating condition parameter correlation compensation model in the PLC's flow control program. Input the calculation formulas for the viscosity calculation formula and the flow compensation coefficient calculation formula, as well as the parameter limitation rules. Debug the subroutine's calculation logic to ensure that it can calculate based on real-time data. , Automatic calculation and ; Write a dynamic target flow adjustment logic program and input the dynamic target flow value. The calculation formula and flow control accuracy requirements; optimize the flow alarm program, and change the alarm reference value to Enter the formulas for high-high and low-low traffic alarm values, and... The alarm dead zone; write the alarm and three-level protection logic program for operating parameters exceeding the threshold, input various thresholds and protection action instructions, and associate the alarm signal with the yellow and red fault indicator lights of the field operation box; After all programming is completed, system integration testing is performed to simulate working conditions with different mud concentrations and temperatures, testing the accuracy of the compensation model's calculations, the response speed of the dynamic adjustment logic, and the reliability of the alarm and protection logic. After successful integration testing, a 72-hour trial run is conducted, during which real-time monitoring is performed. and Adjustments are made based on actual operating data to account for deviations, equipment operating status, and product quality. , The coefficients enable the system to achieve its optimal operating state. Implementation Results: After adopting the method of this invention in the acid regeneration production line of this metallurgical enterprise, the flow control accuracy of the mud pump stabilized at [value missing]. Within this period, compared to before, desilication production efficiency increased by 12%, iron oxide powder product quality qualification rate increased by 15%, and mud cake recycling rate increased by 10%; the load fluctuation range of mud pumps decreased from the original... Down to .

[0026] In summary, this method for frequency conversion flow control of acid regeneration slurry pump completely solves the problem of uncontrollable flow and pressure caused by existing pneumatic and time-based control. At the same time, it makes up for the working condition adaptation defects of existing frequency conversion setpoint control. Through a dynamic compensation model, it achieves high-precision control of slurry pump flow, ensures stable reaction conditions in the acid regeneration desilication process, and fundamentally solves the problem of unstable desilication production efficiency. Furthermore, it avoids sudden changes in equipment load caused by pneumatic and time control, and through dynamic compensation, it matches the speed of the mud pump with the conveying resistance, eliminating the hidden losses caused by local load fluctuations. This extends the service life of the mud pump and pipeline fittings. Moreover, it only requires the addition of concentration and temperature sensors, without the need for new large hardware equipment. The compensation model and control logic are implemented through program segment expansion, and can be directly debugged and deployed in the existing PLC control system of the acid regeneration production line. The transformation cost is low and the construction period is short, making it suitable for mud pump transformation of acid regeneration production lines in various metallurgical industries.

[0027] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for implementing variable frequency flow control of an acid regeneration mud pump, characterized in that: Includes the following steps: S1. Basic adjustment of mud pump speed: A basic architecture for variable frequency speed control of mud pumps is established. The controller connects the frequency converter to the variable frequency motor of the mud pump. The controller pre-stores the baseline flow rate data of mud delivery. The frequency converter receives the frequency adjustment signal from the controller and drives the variable frequency motor to change its speed, thereby realizing the basic adjustment of the mud pump speed. S2, Data Acquisition: Concentration and temperature sensors are installed at the mud pump feed line to collect the actual concentration value of the mud in the acid regeneration process in real time. Actual temperature value The acquired analog signal is transmitted to the analog input unit of the flow control program, and compared with the actual mud flow rate value acquired by the flow detection module. Synchronous storage; S3. Construct a mud viscosity-operating condition parameter correlation compensation model: A mud viscosity-operating condition parameter correlation compensation model is constructed in the flow control program. Based on the process characteristics of acid regeneration mud, a viscosity calculation formula and a flow compensation coefficient calculation formula are preset, and the data is collected in real time. , Calculate the actual viscosity value of the mud. Then through The flow compensation coefficient is derived. ; S4. Dynamic adaptation and adjustment of mud pump speed: The controller will store the pre-stored baseline flow value With flow compensation coefficient The calculation is performed to obtain a dynamic target flow rate value that is adapted to the current mud working conditions. ,by The output frequency of the frequency converter is adjusted based on the reference to achieve dynamic adaptation and adjustment of the mud pump speed; S5. Alarm Program Settings: The actual concentration value of the mud Actual temperature value Actual viscosity value The flow alarm program is incorporated, and alarm logic for exceeding the threshold of operating parameters is set. The alarm signal is transmitted to the field control box and triggers the fault alarm indicator light. At the same time, when the parameter exceeds the threshold, the inverter frequency reduction or shutdown protection signal is output.

2. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: The viscosity calculation formula of the mud viscosity-operating condition parameter correlation compensation model in step S3 is as follows: in, This is the reference viscosity value for the mud. This is the baseline concentration value for the mud. This is the reference temperature value for the mud. This is the coefficient of influence of concentration and viscosity. This is the coefficient for the effect of temperature on viscosity. The range of values ​​is , The range of values ​​is .

3. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 2, characterized in that: The formula for calculating the flow compensation coefficient in step S3 is: when At that time, take ;when At that time, take ;when When taking the actual calculated value, use the actual value.

4. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: The dynamic target flow value in step S4 The calculation formula is: The controller will collect the actual flow rate of the mud in real time. and In contrast, when At that time, the controller sends a frequency adjustment signal to the inverter until... .

5. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: The variable frequency speed control infrastructure described in step S1 includes a variable frequency power supply control module, a cooling fan operation control module, a variable frequency motor operation control module, and a field operation box control module. Each module achieves logical linkage through program segments. The cooling fan operation control includes local and remote dual modes. The variable frequency motor operation control must meet the prerequisite of normal operation of the cooling fan and no fault signals.

6. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: The threshold for the alarm of exceeding the threshold of the operating condition parameter in step S5 is: concentration threshold. , Temperature threshold , Viscosity threshold , .

7. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 6, characterized in that: when , , , , , If any one of the following conditions is met, an operating condition parameter warning is triggered; if two or more conditions are met, the inverter frequency reduction protection is triggered. When this occurs, the inverter shutdown protection is triggered.

8. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: In step S2, the concentration sensor is an online mud concentration meter, and the temperature sensor is a platinum resistance temperature sensor. The signal output type of both is 4~20mA analog signal, which is matched with the analog input unit of the flow control program.

9. The method for implementing variable frequency flow control of acid regeneration mud pump according to claim 1, characterized in that: The flow alarm program includes flow scaling transformation, flow dead zone setting, high-high and low-low flow alarm logic, and high-high flow alarm value. Low flow alarm value Alarm dead zone set .

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