Limestone powder amount control method, system and related device
Through the combination of the PID adjustment module and the frequency converter, the automatic control of the amount of limestone powder is achieved, solving the problem of difficult to quickly adjust the density of limestone slurry, and improving the stability and response speed of the flue gas desulfurization effect.
Patent Information
- Application Number
- CN202510700253.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-28
- Publication Date
- 2025-08-19
AI Technical Summary
In the prior art, the density of limestone slurry is difficult to adjust in time, resulting in poor flue gas desulfurization effect. Especially when the working conditions of the flue gas desulfurization unit change, manual control is difficult to respond quickly.
The feeder is controlled by a PID adjustment module and a frequency converter. By monitoring the density of the limestone slurry tank, the target control amount is calculated and the feeder frequency is adjusted to achieve automatic control of the limestone powder amount.
It improves the timely adjustment of limestone slurry density, ensures the stability and rapid response of the flue gas desulfurization effect.
Smart Images
Figure CN120507961A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of data processing technology, and in particular to a method, system and related device for controlling limestone powder amount. Background Art
[0002] Flue gas desulfurization (FGD) is a technology used to remove sulfur dioxide from flue gas. The main principle of FGD is to convert sulfur dioxide into other easily handled substances through a chemical reaction between sulfur dioxide and an absorbent. Currently, limestone is the most commonly used absorbent in FGD. Its main application method is to mix limestone with water to produce a limestone slurry, which is then transported to an absorber for a chemical reaction with sulfur dioxide.
[0003] Limestone slurry density is crucial to desulfurization effectiveness. Currently, operators manually control the feeder to adjust the output of limestone powder, thereby controlling the limestone slurry density in the limestone slurry tank. Changes in the operating conditions of the flue gas desulfurization unit affect the flue gas volume or the water inflow into the limestone slurry tank, causing the current density of the limestone slurry to fluctuate. Manual control makes it difficult to adjust the limestone powder amount in a timely manner, making it difficult for the limestone slurry density to meet desulfurization requirements, thus affecting flue gas desulfurization effectiveness. Therefore, manual control makes it difficult to adjust the limestone slurry density in a timely manner, thus affecting flue gas desulfurization effectiveness. Summary of the Invention
[0004] In view of the above problems, this application provides a method, system and related device for controlling the amount of limestone powder to achieve the purpose of improving the timeliness of adjusting the density of limestone slurry. The specific solution is as follows:
[0005] In a first aspect, the present application provides a method for controlling limestone powder quantity, which is applied to a powder quantity control system. The powder quantity control system includes a PID adjustment module, a frequency converter, and a feeder. The PID adjustment module is communicatively connected to the frequency converter, and the frequency converter is connected to the feeder. The feeder is provided on a pipeline between a limestone powder bin and a limestone slurry tank. The method for controlling limestone powder quantity includes:
[0006] The frequency converter provides electric energy of a preset frequency to the feeder to control the start-up of the feeder;
[0007] During the operation of the feeder, the PID adjustment module monitors the current slurry density in the limestone slurry tank, and if there is a deviation between the current slurry density and the slurry density set value, calculates a target control amount according to the deviation, and the target control amount is used to control the feeder to output limestone powder of a target weight matching the deviation;
[0008] After obtaining the target control amount, the frequency converter determines a target frequency that matches the target control amount;
[0009] The frequency converter provides the electric energy of the target frequency to the feeder, so that the feeder outputs the limestone powder of the target weight.
[0010] In one possible implementation, calculating the target control amount according to the deviation includes:
[0011] Substitute the current deviation into the incremental PID calculation formula to calculate the control variable;
[0012] The control amount at a previous moment is acquired, and the control amount at the previous moment is added to the control amount variable to obtain the target control amount, where the previous moment is a moment earlier than the current moment.
[0013] In one possible implementation, the incremental PID calculation formula includes a PID proportional formula, a PID integral formula, and a PID differential formula. Substituting the deviation at the current moment into the incremental PID calculation formula to calculate the control variable includes:
[0014] Substitute the deviation into the PID proportional formula to calculate the proportional control amount, substitute the deviation into the PID integral formula to calculate the integral control amount, substitute the deviation into the PID differential formula to calculate the differential control amount;
[0015] A feedforward control quantity is obtained, and the feedforward control quantity, the proportional control quantity, the integral control quantity and the differential control quantity are added together to obtain the control quantity variable.
[0016] In a possible implementation, determining a target frequency that matches the target control amount includes:
[0017] The target frequency corresponding to the target control amount is determined according to a preset relationship table, wherein the preset relationship table is a table recording the corresponding relationship between the control amount output by the PID adjustment module and the frequency of the frequency converter.
[0018] In a possible implementation, the preset frequency is not lower than 35 Hz and not higher than 50 Hz.
[0019] In a possible implementation, during the operation of the feeder, the lower frequency limit value of the frequency converter is 10 Hz, and the upper frequency limit value of the frequency converter is 50 Hz.
[0020] In a possible implementation, when the feeder stops running, the frequency upper limit value and the frequency lower limit value of the frequency converter are both 0 Hz.
[0021] A second aspect of the present application provides a powder quantity control system, the powder quantity control system comprising a PID adjustment module, a frequency converter, and a feeder, the PID adjustment module being communicatively connected to the frequency converter, the frequency converter being connected to the feeder, and the feeder being arranged on a pipeline between a limestone powder bin and a limestone slurry tank;
[0022] The frequency converter is used to provide electric energy of a preset frequency to the feeder to control the start of the feeder, and is also used to determine a target frequency matching the target control amount after obtaining the target control amount, and provide electric energy of the target frequency to the feeder so that the feeder outputs the target weight of limestone powder;
[0023] The PID adjustment module is used to monitor the current slurry density in the limestone slurry tank during the operation of the feeder. If there is a deviation between the current slurry density and the slurry density set value, the target control amount is calculated based on the deviation. The target control amount is used to control the feeder to output limestone powder of a target weight that matches the deviation.
[0024] A third aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:
[0025] The memory is used to store computer programs;
[0026] The processor is configured to execute the computer program so that the electronic device can implement the method for controlling the amount of limestone powder according to the first aspect or any implementation of the first aspect.
[0027] A fourth aspect of the present application provides a computer program product, comprising computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the method for controlling the amount of limestone powder according to the first aspect or any implementation of the first aspect.
[0028] By means of the above technical solution, the present application provides a method, system and related device for controlling the amount of limestone powder. When the feeder is started, the frequency converter starts the feeder at a preset frequency, so that the feeder quickly outputs limestone powder to the limestone slurry tank. Then the frequency converter enters the automatic control state. During the operation of the feeder, the PID adjustment module monitors the current slurry density in the limestone slurry tank in real time. If there is a deviation between the current slurry density and the slurry density setting value, the target control amount is calculated based on the deviation. After the frequency converter obtains the target control amount, it determines the target frequency corresponding to the target control amount, and controls the feeder at the target frequency, adjusting the feeder to output the target weight of limestone powder so that the current slurry density can quickly reach the slurry density setting value. When the feeder is started, this method controls the initial feeding speed of the feeder at a preset frequency to quickly meet the powder feeding requirements. During the operation of the feeder, once the density of the limestone slurry changes, the powder feeder can be quickly controlled by the PID adjustment module and the frequency converter, and the powder feeding amount can be quickly adjusted to quickly adjust the limestone slurry density, effectively improving the timeliness of the limestone slurry density adjustment. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.
[0030] Figure 1 A schematic diagram of the structure of a powder quantity control system provided in an embodiment of the present application;
[0031] Figure 2 A flow chart of a method for controlling the amount of limestone powder provided in an embodiment of the present application;
[0032] Figure 3 This is a hardware structure block diagram of an electronic device provided in this application. DETAILED DESCRIPTION
[0033] The following describes the embodiments of the present application in conjunction with the accompanying drawings. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application.
[0034] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
[0035] The terms "including" and "having" and any variations thereof in the specification of this application and the above-mentioned drawings are intended to cover non-exclusive inclusion, so that a process, method, system, product or apparatus that includes a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, product or apparatus.
[0036] During the power generation process at thermal power plants, coal combustion produces a large amount of flue gas, which contains harmful gases such as sulfur dioxide. To reduce sulfur dioxide emissions, thermal power plants typically use wet flue gas desulfurization (FGD). Wet FGD is a type of FGD technology that desulfurizes the flue gas through a chemical reaction between an absorbent slurry and sulfur dioxide in the flue gas, generating sulfates and sulfites.
[0037] Limestone is the most commonly used absorbent. A feeder in a flue gas desulfurization unit transfers limestone powder from a limestone powder bin to a limestone slurry tank, where it is mixed with water to form a limestone slurry. This slurry is then transported to an absorption tower, where it reacts chemically with sulfur dioxide in the flue gas, desulfurizing the flue gas.
[0038] Therefore, the density of limestone slurry is crucial to the flue gas desulfurization effect. Currently, the density of limestone slurry is mainly controlled by operators by comparing measured indicators and manually controlling the output powder of the feeder. First, when operators manually control the feeder, they need to constantly monitor the density of the limestone slurry in the limestone slurry tank, which is labor-intensive. Second, when the operating conditions of the flue gas desulfurization unit change, it is difficult for operators to feed the slurry in a timely manner, thus affecting the flue gas desulfurization effect. Specifically, when the operating conditions of the flue gas desulfurization unit change, it can lead to an increase or decrease in the flue gas volume (increase or decrease in sulfur dioxide), an increase or decrease in the water inflow into the limestone slurry tank, and other problems. As a result, the density of the limestone slurry in the limestone slurry tank changes accordingly. In order to achieve a better flue gas desulfurization effect, the limestone slurry in the limestone slurry tank needs to be quickly adjusted. Due to the sudden changes in the operating conditions of the flue gas desulfurization unit, it is difficult for the operator to respond in time with manual control of feeding, making it difficult for the limestone slurry density in the limestone slurry tank to quickly meet the desulfurization requirements in a short period of time, thus affecting the flue gas desulfurization effect.
[0039] Of course, there are also methods currently available to achieve automatic control of feeders through deep neural networks. The specific process can be as follows: collecting on-site operating parameters and batch historical operating parameter data, establishing a database, and preprocessing the parameter data in the database; using deep neural networks to predict and optimize the delay parameters in the collected parameters; based on the processed parameter data, using a multivariable reinforcement learning algorithm to calculate the automatic control parameters of the feeder in real time; and sending the automatic control parameters to the control system to achieve automatic control of the feeder. The above process is too complex and time-consuming to establish a database and a deep neural network control system.
[0040] To address the above issues, the present invention provides a method for controlling the amount of limestone powder. This method utilizes a PID control module and a frequency converter to automatically control a feeder. The control process is simple and easy to implement, and it also improves the timeliness of the feeder's feeding. The following describes the method for controlling the amount of limestone powder in the present invention in detail, with reference to the accompanying drawings.
[0041] The limestone powder control method provided in the embodiment of the present application can be applied to a powder control system, such as Figure 1 As shown, the powder quantity control system may include a PID adjustment module 1, a frequency converter 2, and a feeder 3. The PID adjustment module 1 is communicatively connected to the frequency converter 2, which is connected to the feeder 3. The feeder 3 is disposed on a pipeline between the limestone powder silo 4 and the limestone slurry tank 5. Process water flows through another pipeline into the limestone slurry tank 5, where it is stirred and mixed with the limestone powder to form limestone slurry. A water supply valve may be provided on the process water circulation pipeline to adjust the amount of process water entering the limestone slurry tank 5. In addition, the limestone powder silo and the limestone slurry tank may have one pipeline or multiple pipelines (for example, two pipelines), and a feeder and a frequency converter may be provided in each pipeline.
[0042] PID regulation (Proportional-Integral-Derivative Control) is a control algorithm that achieves precise control of a controlled object through a combination of proportional (P), integral (I), and differential (D) steps. In this embodiment, PID regulation specifically refers to incremental PID regulation, an improvement on the PID regulation algorithm. Incremental PID regulation achieves control by calculating the increment (not the absolute value) of the controlled variable. It offers advantages such as simple calculation, strong anti-interference capabilities, and ease of disturbance-free switching.
[0043] A variable frequency drive (VFD) is a power control device that controls AC motors by varying the frequency of the motor's operating power supply. In this embodiment, the VFD controls the feeder's feed speed by varying the output frequency to the feeder, thereby changing the feeder's operating power supply frequency. The VFD can include a built-in control module to control the VFD's output frequency, or it can be controlled directly by independent control software. In this embodiment, the VFD is primarily controlled by an independent VFD operator station.
[0044] A feeder can be a device that evenly and continuously transports material from a storage device to the next device or process. The feeder used in this embodiment is a star-shaped feeder. A motor and a reducer drive the impeller to rotate within the housing. Material falls from the upper hopper or feeding device of the housing into the impeller's cavity, then rotates with the impeller to the lower portion of the housing and is discharged through the discharge port.
[0045] Reference Figure 2 , Figure 2 A flow chart of a method for controlling the amount of limestone powder provided in an embodiment of the present application is shown as follows: Figure 2 As shown, the method for controlling the amount of limestone powder may include steps S10 to S13, and these steps are described in detail below.
[0046] S10, the frequency converter provides the feeder with electric energy of a preset frequency to control the feeder to start.
[0047] Among them, the preset frequency can be a high frequency, so that the feeder can quickly meet the powder feeding requirements as soon as it is started. Specifically, the preset frequency can be not less than 35Hz and not higher than 50Hz. The starting working power frequency output by the inverter to the feeder directly crosses the small frequency area and controls the feeder directly from 35Hz, which can speed up the response time of the feeder. Within a short time after the feeder is started, the inverter enters the automatic control mode. Specifically, within three seconds after the feeder is started, it continues to feed powder at a frequency of 35Hz. Three seconds after the feeder is started, the inverter enters the automatic control mode, and the PID adjustment module monitors the limestone slurry density in the limestone slurry box in real time, and automatically outputs the control amount to the inverter, so that the inverter can automatically adjust the output frequency of the feeder.
[0048] Furthermore, within three seconds of the feeder starting, if the inverter has other control instructions, the inverter will prioritize continuing to control the feeder at the preset frequency. For example, within three seconds of the feeder starting, if the operator manually changes the inverter output frequency through the inverter operation station, the inverter operation station will prioritize continuing to control the feeder at the output frequency of 35Hz.
[0049] S11. During the operation of the feeder, the PID control module monitors the current slurry density in the limestone slurry tank. If there is a deviation between the current slurry density and the set slurry density, the target control amount is calculated based on the deviation. The target control amount is used to control the feeder to output limestone powder of a target weight that matches the deviation.
[0050] In this embodiment, a densitometer can be provided in the limestone slurry tank so that the PID control module can monitor the current slurry density in the limestone slurry tank. The slurry density setting value can be a preset fixed value, a slurry density value determined in advance through experiments or tests. When the current slurry density is the slurry density setting value, the flue gas desulfurization effect is better. When the operating conditions of the flue gas desulfurization unit change, the flue gas volume increases or decreases, and the current slurry density in the limestone slurry tank decreases or increases accordingly, so that the current slurry density is no longer close to the slurry density setting value, resulting in a decrease in the flue gas desulfurization effect. Therefore, when the PID control module detects a deviation between the current slurry density and the slurry density setting value, the target control amount is calculated based on the deviation. The frequency converter changes the output frequency based on the target control amount, thereby changing the speed of the feeder, so that the limestone powder output increases or decreases accordingly, and the water output can remain unchanged, so as to quickly adjust the current slurry density to the slurry density setting value. When the PID adjustment module detects that there is no deviation between the current slurry density and the slurry density set value, no adjustment is required and the frequency converter continues to control the feeder at the current frequency.
[0051] Specifically, the specific process of the PID adjustment module calculating the target control amount according to the deviation can be shown in steps 1 and 2:
[0052] Step 1: Substitute the current deviation into the incremental PID calculation formula to calculate the control variable;
[0053] Step 2: Get the control amount at the previous moment, and add the control amount at the previous moment to the control amount variable to obtain the target control amount. The previous moment is a moment earlier than the current moment.
[0054] The control variable can represent the adjustment relative to the previous moment, including the direction and magnitude of the adjustment. The target control variable can refer to the signal value required to be applied to the actuator at the current moment, including the actuator's action intensity. Examples include motor strength, valve opening, and thermal power.
[0055] The incremental PID calculation formula can be divided into four parts: proportional part, integral part, differential part and feedforward control part. Therefore, the incremental PID calculation formula can be expressed as follows:
[0056] ;
[0057] in, It can represent the control variable at the current moment; Can express proportional control quantity; Can represent the integral control quantity; Can represent the differential control quantity; It can be expressed as the feedforward control quantity. Then the calculation formula of the target control quantity can be as follows:
[0058] ;
[0059] in, It can represent the target control amount; It can represent the control quantity at the previous moment. It can represent the control variable at the current moment.
[0060] The proportional part, integral part, and differential part in the incremental PID calculation formula can each correspond to a detailed formula to calculate the corresponding control variable. Therefore, the incremental PID calculation formula can include the PID proportional formula, PID integral formula, PID differential formula, and feedforward control part. The specific process of calculating the control variable can be as follows:
[0061] Substitute the deviation into the PID proportional formula to calculate the proportional control amount, substitute the deviation into the PID integral formula to calculate the integral control amount, substitute the deviation into the PID differential formula to calculate the differential control amount, obtain the feedforward control amount, and add the feedforward control amount, proportional control amount, integral control amount and differential control amount to obtain the control amount variable.
[0062] Among them, the formula forms of PID proportional formula, PID integral formula and PID differential formula can be shown as follows:
[0063] ;
[0064] ;
[0065] ;
[0066] The incremental PID calculation formula can also be expressed as:
[0067] ;
[0068] in, Can represent a variable in PID regulation; Can represent the proportionality factor; It can express the deviation of the current moment; It can represent the integration period; can represent the differential coefficient, Can represent differential period; can represent the feedforward control part, .
[0069] The feedforward control component can be provided by a feedforward controller to the PID adjustment module. A feedforward controller is an active control component based on disturbance prediction. It predicts the impact of disturbances on the system in advance and compensates for them before they affect the system output, thereby reducing or eliminating the effects of disturbances. Therefore, this embodiment incorporates the output of the feedforward controller when the PID adjustment module calculates the target control variable, effectively reducing the impact of environmental disturbances (such as ambient temperature).
[0070] Furthermore, this embodiment can also set limits for the target control quantity output by the PID adjustment module, including upper and lower limits of the target control quantity. When the target control quantity output by the PID adjustment module reaches the upper or lower limit, an alarm can be issued. Furthermore, during the operation of the PID adjustment module, the PID adjustment module can also receive a lock-up increase instruction and a lock-down decrease instruction. When the PID adjustment module receives a lock-up increase instruction, the target control quantity output by the PID adjustment module can gradually decrease, but cannot gradually increase; when the PID adjustment module receives a lock-down decrease instruction, the target control quantity output by the PID adjustment module can gradually increase, but cannot gradually decrease.
[0071] S12, after the frequency converter obtains the target control amount, it determines the target frequency that matches the target control amount;
[0072] S13. The frequency converter provides electric energy of a target frequency to the feeder, so that the feeder outputs limestone powder of a target weight.
[0073] Among them, the target frequency is: the output frequency of the frequency converter to the feeder at the current moment. After the control part of the frequency converter obtains the target control quantity, since the target control quantity is difficult to be directly applied to the frequency converter, the control part of the frequency converter can first convert the target control quantity into a control signal that the frequency converter can recognize, and then control the frequency converter with the control signal. Specifically, in this embodiment, the frequency converter operation station determines the target frequency corresponding to the target control quantity according to the preset relationship table, and then outputs the control signal of the target frequency to control the frequency converter to output the target frequency to the feeder. Among them, the preset relationship table is: a table recording the correspondence between the control quantity output by the PID adjustment module and the frequency of the frequency converter. Of course, in another optional embodiment, the frequency converter operation station can directly perform signal mapping on the target control quantity and convert the target control quantity into the control signal of the frequency converter.
[0074] When the frequency converter controls the feeder at the target frequency, the feeder feeds powder at a speed corresponding to the target frequency, so that the feeder outputs the target weight of limestone powder. When the target weight of limestone powder enters the limestone slurry tank and is mixed with water, the density of the limestone slurry in the limestone slurry tank can be close to or equal to the slurry density set value.
[0075] Specifically, during feeder operation, the inverter operating station automatically limits the inverter's output frequency to upper and lower limits. The inverter operating station automatically sets the inverter's lower frequency limit to 10Hz and its upper frequency limit to 50Hz. This allows the inverter to have sufficient margin to adjust its output frequency and prevents damage to the feeder caused by low output frequency, which could result in low limestone slurry density, and high output frequency, which could result in damage to the feeder.
[0076] Furthermore, in this embodiment, when the feeder stops running, the output frequency of the inverter is limited to between 0-0, that is, the frequency upper limit value and the frequency lower limit value of the inverter are both set to 0Hz, which can prevent the inverter from still working after the feeder stops running, effectively reducing power loss.
[0077] In another alternative embodiment, the inverter operation station can switch between automatic control mode and manual mode. In manual mode, the operator controls the inverter output frequency. For example, if the feeder stops operating, the inverter operation station immediately switches to manual mode, and the operator continues to control the inverter.
[0078] The present application provides a method for controlling the amount of limestone powder. When the feeder is started, the frequency converter starts the feeder at a preset frequency, so that the feeder quickly outputs limestone powder to the limestone slurry tank, and then the frequency converter enters an automatic control state. During the operation of the feeder, the PID adjustment module monitors the current slurry density in the limestone slurry tank in real time. If there is a deviation between the current slurry density and the slurry density setting value, the target control amount is calculated according to the deviation. After the frequency converter obtains the target control amount, it determines the target frequency corresponding to the target control amount, and controls the feeder at the target frequency to adjust the feeder to output the target weight of limestone powder so that the current slurry density can quickly reach the slurry density setting value. When the feeder is started, the method controls the initial feeding speed of the feeder at a preset frequency to quickly meet the powder feeding requirements, and during the operation of the feeder, once the limestone slurry density changes, the powder feeder can be quickly controlled by the PID adjustment module and the frequency converter, and the powder feeding amount can be quickly adjusted to quickly adjust the limestone slurry density, effectively improving the timeliness of the limestone slurry density adjustment.
[0079] Furthermore, this embodiment realizes automatic control of the feeder only through the PID adjustment module and the frequency converter. This method is easy to implement and does not require complicated training.
[0080] A method for controlling the amount of limestone powder provided in an embodiment of the present application has been described above. A system using the method for controlling the amount of limestone powder will be described below.
[0081] The powder quantity control system may include a PID adjustment module, a frequency converter, and a feeder. The PID adjustment module is communicatively connected to the frequency converter, and the frequency converter is connected to the feeder. The feeder is arranged on a pipeline between the limestone powder bin and the limestone slurry tank. The limestone powder quantity control method includes:
[0082] The frequency converter is used to provide the feeder with electric energy of a preset frequency to control the start of the feeder. It is also used to obtain the target control amount, determine the target frequency that matches the target control amount, and provide the feeder with electric energy of the target frequency so that the feeder outputs the target weight of limestone powder.
[0083] The PID adjustment module is used to monitor the current slurry density in the limestone slurry tank during the operation of the feeder. If there is a deviation between the current slurry density and the set slurry density, the target control amount is calculated based on the deviation. The target control amount is used to control the feeder to output limestone powder of a target weight that matches the deviation.
[0084] In one possible implementation, the PID adjustment module calculates the target control amount based on the deviation, which can be specifically configured as follows:
[0085] The PID adjustment module brings the deviation at the current moment into the incremental PID calculation formula, calculates the control quantity variable, obtains the control quantity at the previous moment, and adds the control quantity at the previous moment to the control quantity variable to obtain the target control quantity. The previous moment is a moment earlier than the current moment.
[0086] In one possible implementation, the incremental PID calculation formula includes the PID proportional formula, the PID integral formula, and the PID differential formula. The PID adjustment module brings the current deviation into the incremental PID calculation formula to calculate the control variable. Specifically, it can be configured as follows:
[0087] Substitute the deviation into the PID proportional formula to calculate the proportional control amount, substitute the deviation into the PID integral formula to calculate the integral control amount, substitute the deviation into the PID differential formula to calculate the differential control amount, obtain the feedforward control amount, and add the feedforward control amount, proportional control amount, integral control amount and differential control amount to obtain the control amount variable.
[0088] In one possible implementation, the frequency converter determines a target frequency that matches the target control variable, which can be specifically configured as follows:
[0089] The target frequency corresponding to the target control quantity is determined according to a preset relationship table. The preset relationship table is: a table recording the corresponding relationship between the control quantity output by the PID adjustment module and the frequency of the frequency converter.
[0090] In a possible implementation, the preset frequency is not lower than 35 Hz and not higher than 50 Hz.
[0091] In a possible implementation, during the operation of the feeder, the lower frequency limit value of the frequency converter is 10 Hz, and the upper frequency limit value of the frequency converter is 50 Hz.
[0092] In a possible implementation, when the feeder stops running, the frequency upper limit value and the frequency lower limit value of the frequency converter are both 0 Hz.
[0093] An electronic device is also provided in an embodiment of the present application. Figure 3 , which shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present application. The electronic device in the embodiments of the present application may include, but is not limited to, fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, etc. Figure 3 The electronic device shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.
[0094] like Figure 3 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 301, which can perform various appropriate actions and processes based on programs stored in a read-only memory (ROM) 302 or programs loaded from a storage device 308 into a random access memory (RAM) 303. When the electronic device is powered on, the RAM 303 also stores various programs and data required for the operation of the electronic device. The processing device 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.
[0095] Typically, the following devices may be connected to the I / O interface 305: an input device 306 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 307 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 308 including, for example, a memory card, a hard disk, etc.; and a communication device 309. The communication device 309 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Figure 3 The electronic device is shown with various devices, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.
[0096] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any of the limestone powder amount control methods provided in the embodiments of the present application.
[0097] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any of the limestone powder control methods provided in the embodiments of the present application.
[0098] It should also be noted that the system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the system embodiments provided in this application, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.
[0099] Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course can also be implemented by special hardware including application-specific integrated circuits, special CPUs, special memories, special components, etc. In general, all functions performed by computer programs can be easily implemented with corresponding hardware, and the specific hardware structures used to implement the same function can also be diverse, such as analog circuits, digital circuits or special circuits, etc. However, for the present application, software program implementation is a better implementation method in most cases. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer's floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk or optical disk, etc., and includes a number of instructions to enable a computer device (which can be a personal computer, training equipment, or network equipment, etc.) to execute the methods described in each embodiment of the present application.
[0100] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.
[0101] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, a computer, a training device or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website, a computer, a training device or a data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).
[0102] Each embodiment in this specification is described in a related manner. Similar portions between the embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences from other embodiments. In particular, the device embodiments are generally similar to the method embodiments, so their description is relatively simple. For related portions, refer to the description of the method embodiments.
[0103] It is understandable that before using the technical solutions disclosed in the various embodiments of this disclosure, the type, scope of use, usage scenarios, etc. of the personal information involved in this disclosure should be informed to the user and the user's authorization should be obtained in an appropriate manner in accordance with relevant laws and regulations.
[0104] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included in the protection scope of the present application.
Claims
1. A method for controlling the amount of limestone powder, characterized in that: The invention is applied to a powder quantity control system, which includes a PID adjustment module, a frequency converter and a feeder. The PID adjustment module is communicatively connected to the frequency converter, and the frequency converter is connected to the feeder. The feeder is arranged on a pipeline between a limestone powder bin and a limestone slurry tank. The method for controlling the amount of limestone powder includes: The frequency converter provides electric energy of a preset frequency to the feeder to control the start-up of the feeder; During the operation of the feeder, the PID adjustment module monitors the current slurry density in the limestone slurry tank, and if there is a deviation between the current slurry density and the slurry density set value, calculates a target control amount according to the deviation, and the target control amount is used to control the feeder to output limestone powder of a target weight matching the deviation; After obtaining the target control amount, the frequency converter determines a target frequency that matches the target control amount; The frequency converter provides the electric energy of the target frequency to the feeder, so that the feeder outputs the limestone powder of the target weight.
2. The method for controlling the amount of limestone powder according to claim 1, wherein Calculating a target control amount according to the deviation includes: Substitute the current deviation into the incremental PID calculation formula to calculate the control variable; The control amount at a previous moment is acquired, and the control amount at the previous moment is added to the control amount variable to obtain the target control amount, where the previous moment is a moment earlier than the current moment.
3. The method for controlling the amount of limestone powder according to claim 1, wherein The incremental PID calculation formula includes a PID proportional formula, a PID integral formula, and a PID differential formula. Substituting the deviation at the current moment into the incremental PID calculation formula to calculate the control variable includes: Substitute the deviation into the PID proportional formula to calculate the proportional control amount, substitute the deviation into the PID integral formula to calculate the integral control amount, substitute the deviation into the PID differential formula to calculate the differential control amount; A feedforward control quantity is obtained, and the feedforward control quantity, the proportional control quantity, the integral control quantity and the differential control quantity are added together to obtain the control quantity variable.
4. The method for controlling the amount of limestone powder according to claim 1, wherein The determining of the target frequency matching the target control amount includes: The target frequency corresponding to the target control amount is determined according to a preset relationship table, wherein the preset relationship table is a table recording the corresponding relationship between the control amount output by the PID adjustment module and the frequency of the frequency converter.
5. The method for controlling the amount of limestone powder according to claim 1, wherein: The preset frequency is not lower than 35 Hz and not higher than 50 Hz.
6. The method for controlling the amount of limestone powder according to claim 1, wherein: During the operation of the feeder, the lower frequency limit value of the frequency converter is 10 Hz, and the upper frequency limit value of the frequency converter is 50 Hz.
7. The method for controlling the amount of limestone powder according to claim 1, wherein: When the feeder stops running, the frequency upper limit value and the frequency lower limit value of the frequency converter are both 0 Hz.
8. A powder quantity control system, characterized in that: The powder quantity control system includes a PID adjustment module, a frequency converter and a feeder, wherein the PID adjustment module is communicatively connected to the frequency converter, the frequency converter is connected to the feeder, and the feeder is arranged on the pipeline between the limestone powder bin and the limestone slurry tank; The frequency converter is used to provide electric energy of a preset frequency to the feeder to control the start of the feeder, and is also used to determine a target frequency matching the target control amount after obtaining the target control amount, and provide electric energy of the target frequency to the feeder so that the feeder outputs the target weight of limestone powder; The PID adjustment module is used to monitor the current slurry density in the limestone slurry tank during the operation of the feeder. If there is a deviation between the current slurry density and the slurry density set value, the target control amount is calculated based on the deviation. The target control amount is used to control the feeder to output limestone powder of a target weight that matches the deviation.
9. An electronic device, characterized in that: comprising at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is configured to execute the computer program so that the electronic device can implement the method for controlling the amount of limestone powder according to any one of claims 1 to 7.
10. A computer program product, characterized in that The method comprises computer-readable instructions, which, when executed on an electronic device, enable the electronic device to implement the method for controlling the amount of limestone powder according to any one of claims 1 to 7.