Method and system for adjusting output of activation coal feeder of European silo based on PID (Proportion Integration Differentiation) control

Abstract

The invention relates to a PID (Proportion Integration Differentiation) control-based output regulation method and system for an activation coal feeder of an European silo, and solves the problems that the manual output regulation stability is poor and the operation depends on experience in the prior art. According to the method, the target coal flow is preset to serve as reference input, the electronic scale is used for collecting the actual flow in real time, deviation is calculated, the controlled quantity is generated through proportional, integral and differential adjustment of the PID controller, the air pressure of an oscillation motor of the activated coal feeder is automatically adjusted, and the closed-loop control process of measurement, deviation calculation and automatic adjustment is formed. The system comprises a target setting unit, a flow acquisition unit, a PID control unit and an execution unit. According to the method, the working pressure of operators can be reduced, the coal flow control precision and the bunker adding process stability can be improved, the bunker adding amount and time can be accurately estimated, technical support is provided for a subsequent automatic bunker adding system, and the method has the advantages of economy and intelligence.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel transportation in thermal power plants, and particularly to a method and system for regulating the output of an Oerlikon bin activation coal feeder based on PID control. Background Art

[0002] In the fuel transportation system of a thermal power plant, the Oerlikon bin, as a key device for storing and transporting coal, the stability and automation level of its output regulation directly affect the boiler combustion efficiency and the safety of the overall power generation system. Currently, the Oerlikon bin discharging control scheme adopted by Huaneng Shanghai Shidongkou No. 1 Power Plant mainly realizes the quantitative output of coal through an activation coal feeder. Specifically, this scheme relies on manual operation, adjusts the air pressure to change the output of the vibration motor, thereby controlling the coal flow, and uses an electronic scale to monitor the discharging amount in real time to judge the output size.

[0003] However, the existing technology has significant defects: on the one hand, the coal flow is affected by multiple factors such as coal accumulation degree, coal quality viscosity, and material bulk density, and is prone to periodic or random fluctuations, resulting in the deviation of the actual discharging amount from the target value; on the other hand, the current adjustment process completely relies on the centralized control personnel to observe the electronic scale data in real time and manually adjust the air pressure. The frequency of manual intervention is high and the response is lagged, which not only increases the workload of the operating personnel, but also is difficult to cope with the dynamically changing working conditions, resulting in insufficient stability during the coal feeding process. In addition, due to the lack of an automatic adjustment mechanism, the system cannot perform adaptive control according to the preset target flow, so that the estimation accuracy of key parameters such as the coal feeding amount and the coal feeding time is relatively low, seriously restricting the realization of the subsequent automatic coal feeding technology.

[0004] The core problem of the existing technology is that it relies on manual experience for output regulation, does not form a closed-loop feedback control, and cannot compensate the influence of external disturbances on the flow in real time and dynamically, resulting in low control accuracy and efficiency, and it is difficult to meet the requirements of intelligent and unmanned operation of modern power plants.

[0005] In summary, there is an urgent need for an automatic adjustment method based on existing equipment to achieve stable control of the Oerlikon bin output, reduce labor costs, and provide technical support for the fully automatic operation of the fuel transportation system. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a method and system for regulating the output of an Oerlikon bin activation coal feeder based on PID control, so as to solve or partially solve the problems of relying on manual intervention, low control accuracy, and poor stability in the output regulation of the Oerlikon bin activation coal feeder.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] An aspect of the present invention provides a method for regulating the output of an Ouro bunker activation coal feeder based on PID control, comprising the following steps:

[0009] Step S1, obtaining a preset target coal flow rate as the reference input n(t) of the PID control system;

[0010] Step S2, collecting the actual coal flow rate y(t) of the Ouro bunker activation coal feeder in real time through an electronic scale;

[0011] Step S3, calculating the deviation e(t) between the reference input n(t) and the actual coal flow rate y(t): e(t) = n(t) - y(t);

[0012] Step S4, using a PID controller to perform proportional, integral, and differential regulation on the deviation e(t) to obtain the control quantity u(t):

[0013] Step S5, adjusting the output of the activation coal feeder according to the control quantity u(t), and realizing coal flow control by changing the air pressure of the vibration motor;

[0014] Step S6, repeating steps S2 - S5 to form a closed-loop control process until the actual coal flow rate y(t) stabilizes to the target coal flow rate n(t),

[0015] wherein, in the said step S4, the output expression of the PID controller is:

[0016]

[0017] wherein, K p is the proportionality coefficient, T i is the integral time constant, T d is the differential time constant.

[0018] As a preferred technical solution, in the said step S3, the deviation e(t) is used to characterize the error direction and amplitude between the current output and the target flow rate, and serves as the input signal of the PID controller.

[0019] As a preferred technical solution, in the said step S4, the deviation is amplified or reduced in real time through the proportionality coefficient K p The integral regulation link eliminates the static error by accumulating historical deviations, and the differential regulation link suppresses flow fluctuations by predicting the deviation change rate.

[0020] As a preferred technical solution, the parameters K p 、T i 、T d of the said PID controller are determined through on-site working condition debugging based on the influence of the coal accumulation degree and the viscosity of the coal quality on the coal flow rate.

[0021] As a preferred technical solution, it further includes:

[0022] Step S7, in response to u(t) > u max and the duration exceeding the threshold, it is determined that there is a blockage in the activated coal feeder, and an alarm signal is issued, where u max is the maximum power of the preset output of the activated coal feeder.

[0023] Another aspect of the present invention provides a regulating system for the output of an activated coal feeder in an Euro bin based on PID control, including:

[0024] A target setting unit for presetting a target coal flow rate and outputting a reference input n(t);

[0025] A flow rate acquisition unit, including an electronic scale, for real-time acquisition of the actual coal flow rate y(t) of the activated coal feeder;

[0026] A deviation calculation unit for calculating the deviation e(t) between the reference input n(t) and the actual flow rate y(t);

[0027] A PID control unit, with built-in proportional, integral, and differential operation modules, generating a control quantity u(t) according to the deviation e(t). The output expression of the PID control unit is:

[0028]

[0029] where, K p is the proportionality coefficient, T i is the integral time constant, T d is the differential time constant;

[0030] An execution unit, including the activated coal feeder and its oscillation motor air pressure regulation module, for adjusting the output according to the control quantity u(t) and controlling the coal flow rate;

[0031] Among them, the target setting unit, the flow rate acquisition unit, the deviation calculation unit, the PID control unit, and the execution unit are connected in sequence to form a closed-loop control system.

[0032] As a preferred technical solution, the flow rate acquisition unit is electrically connected to the PID control unit, and feeds back the real-time flow rate signal to the PID control unit as the input of the closed-loop control.

[0033] As a preferred technical solution, the deviation is amplified or reduced in real time through the proportionality coefficient K p The integral regulation link eliminates the static error by accumulating historical deviations, and the differential regulation link suppresses the flow rate fluctuation by predicting the deviation change rate.

[0034] As a preferred technical solution, the parameters K p 、T i 、Td It is determined through on-site working condition debugging based on the influence of the degree of coal accumulation and the viscosity of coal quality on the coal flow rate.

[0035] Another aspect of the present invention provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs include instructions for executing the aforementioned method for regulating the output of the Euro bin activation coal feeder based on PID control.

[0036] Another aspect of the present invention provides a computer-readable storage medium, which is characterized by including one or more programs for execution by one or more processors of an electronic device, and the one or more programs include instructions for executing the aforementioned method for regulating the output of the Euro bin activation coal feeder based on PID control.

[0037] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0038] (1) Achieving closed-loop adaptive control and improving control accuracy: The present invention utilizes the collaborative action of the proportional, integral, and differential links of the PID algorithm to compensate in real time for the interference of external factors such as the degree of coal accumulation and the viscosity of coal quality on the flow rate, realizing stable control under dynamic working conditions. By means of closed-loop feedback, the flow rate deviation is corrected in real time, fluctuations are suppressed, and the coal flow rate is stabilized within the target range, ensuring the stability of the coal addition process.

[0039] (2) Laying a foundation for automatic control: The present invention precisely estimates parameters such as the coal addition quantity and the coal addition time through preset target flow rates and an automatic adjustment mechanism, providing a data interface and a control model for the subsequent full-process automatic coal addition system, and the system can be seamlessly integrated into the existing distributed control system of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flowchart of the method for regulating the output of the Euro bin activation coal feeder based on PID control in the embodiment;

[0041] Figure 2 It is a schematic diagram of the system for regulating the output of the Euro bin activation coal feeder based on PID control in the embodiment;

[0042] Figure 3 It is a schematic diagram of the electronic device in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention shall fall within the protection scope of the present invention.

[0044] Example 1

[0045] In view of the problems existing in the aforementioned prior art, this embodiment provides a method for regulating the output of an Ouro bunker activation coal feeder based on PID control. Based on the PID regulation in the automatic control theory, through the closed-loop control logic of measuring and correcting deviations, the flow signal real-time feedback by the electronic scale is compared with the target value, and after calculation by the PID algorithm, a control signal is output to the activation coal feeder, constituting a closed-loop system of target setting, real-time feedback, and automatic regulation. The proportional link quickly responds to the current deviation, the integral link eliminates the long-term static error, and the derivative link predicts the trend and suppresses overshoot. The combination of the three realizes the precise dynamic control of the output, solving the problems of hysteresis and instability of traditional manual regulation.

[0046] Taking the Ouro bunker discharging system of a certain power plant as an example, the existing equipment includes:

[0047] An activation coal feeder that controls the output by adjusting the air pressure of the vibration motor.

[0048] An electronic scale installed below the discharging port of the coal feeder for collecting the actual coal flow rate y(t).

[0049] A DCS control system, the existing distributed control system of the power plant, integrates the PID control algorithm module of this embodiment, and supports signal input and output and parameter debugging.

[0050] See Figure 1 , this method includes the following steps:

[0051] Step S1, target setting and initialization.

[0052] According to the boiler load demand, input the target coal flow rate n(t) = 80t / h through the DCS operation interface as the reference input of the PID control system. According to the historical operation data and coal quality characteristics, preset the initial control parameters: the proportional coefficient K p = 0.8, which is used to initially amplify the deviation response, the integral time constant T i = 10s, which is used to balance the static error elimination speed and system stability, and T d = 2s, which is used to suppress short-term flow fluctuations. Preferably, for the scenario where the boiler load changes frequently, the DCS system can receive the scheduling instruction in real time, dynamically adjust the target flow rate n(t), and the PID controller automatically adapts to the new target and re-enters the closed-loop regulation.

[0053] Step S2, real-time flow rate acquisition.

[0054] The DCS system reads the actual coal flow rate y(t) output by the electronic scale in real time with a period of 1 s. The first collected value is y(t) = 75 t / h, that is, the initial output is lower than the target value. Thereafter, the collected data is subjected to moving average filtering (window length 3 s) to eliminate high-frequency noise interference, and the smoothed flow signal y ′ (t) is obtained.

[0055] Step S3, deviation calculation.

[0056] According to e(t) = n(t) - y ′ (t), the deviation e(0) = 80 - 75 = 5 t / h is calculated, which indicates that the current output needs to be increased to increase the flow rate. Its positive deviation means that the actual flow rate is lower than the target value and the output of the coal feeder needs to be increased, and vice versa for negative deviation.

[0057] Step S4, PID regulation calculation.

[0058] It includes proportional regulation, integral regulation and derivative regulation branches:

[0059] Proportional regulation: P = K p ·e(t);

[0060] Integral regulation: Integrate from the initial moment to calculate the cumulative historical deviation. The integral term at the first calculation:

[0061]

[0062] Derivative regulation: By calculating the deviation change rate The derivative term is obtained. At the first regulation, since there is no previous data, the derivative term is temporarily set to 0. In subsequent cycles, according to the deviation at adjacent moments:

[0063]

[0064] The outputs of each branch are synthesized to obtain the control quantity:

[0065] u(t) = P + I + D

[0066] Step S5, output regulation and closed-loop feedback.

[0067] The control quantity u(t) is converted into the air pressure signal of the vibration motor. The DCS system sends an air pressure regulation command to the activation coal feeder to drive the motor to increase the vibration amplitude, increase or decrease the coal flow rate. After waiting for 1 s, return to step S2 to collect the new actual flow rate y(t), calculate the new deviation, and repeat the PID regulation process until |e(t)| ≤ 0.5 t / h for three consecutive measurements, where 0.5 is the preset stability threshold. Thereafter, the system enters the steady state. In response to u(t) > u max and the maintenance time exceeds the threshold, it is determined that there is a blockage phenomenon in the activation coal feeder, and an alarm signal is issued, where umax is the maximum output power of the preset activated coal feeder.

[0068] In the above steps, the parameter K p , T d , T i needs to be set according to the on-site working conditions. Specifically, when the coal bunker has a high degree of coal accumulation, such as when the inner wall is sticky with coal and the feeding is not smooth, appropriately increase K p , for example, set it to K p = 1.0 to accelerate the deviation response speed. If the coal material in the coal feeder is lignite or other coal materials with high viscosity, and the flow rate fluctuates frequently, increase T d , for example, take T d = 3s to enhance the inhibitory effect of the differential link on the change rate. If there is a static error during long-term operation, for example, e(t) is always positive, then reduce T i , for example, take T i = 8s to accelerate the elimination of errors by the integral link.

[0069] When the actual flow rate continuously maintains within the range of 80 ± 1 t / h for 5 consecutive cycles, it is determined that the system reaches a stable state and the parameter adjustment is stopped.

[0070] Compared with the existing method, this method reduces the fluctuation range to meet the requirements of boiler combustion for the stability of coal flow rate. In addition, the operator does not need to monitor the electronic scale data in real time, only needs to set the target flow rate in the initial stage and regularly check the PID parameters, reducing the average daily adjustment times. Finally, through the transformation of existing equipment, no new hardware investment is required, and the feeding time is reduced after the system is put into use, providing a reliable data basis for the automatic feeding system. This method embeds the PID algorithm into the existing DCS system, forms a closed loop by using the feedback of the electronic scale, realizes the automatic and precise control of the output of the activated coal feeder, effectively solves the problems of hysteresis and instability of manual adjustment, and verifies the feasibility and practicability of the invention.

[0071] Embodiment 2

[0072] Based on Embodiment 1, this embodiment provides an output regulation system for the Euro bin activated coal feeder based on PID control, which is used to implement the output regulation method of the Euro bin activated coal feeder as in Embodiment 1.

[0073] See Figure 2 , the system includes the following parts:

[0074] The target setting unit is used to preset the target coal flow rate and output the reference input n(t). It includes a human-machine interface and a storage module. The human-machine interface is implemented by a DCS operation station, supporting the input of the target coal flow rate and the display of parameters. The storage module is implemented by an internal register to save the target value n(t) and the PID control parameter group (K p, T i , T d )。

[0075] The flow rate acquisition unit includes an electronic scale for real-time acquisition of the actual coal flow rate y(t) of the activated coal feeder. Specifically, the electronic scale is installed at the outlet of the activated coal feeder, and the actual coal flow rate y(t) is transmitted to the DCS in real time through a 4-20 mA analog signal.

[0076] The deviation calculation unit is used to calculate the deviation e(t) between the reference input n(t) and the actual flow rate y(t). Specifically, it includes a DCS controller and a signal processor. The DCS controller has a built-in custom PID algorithm function block, which supports deviation calculation, proportional / integral / differential operations, and control quantity output. The signal processor is used to filter and range-convert the acquired signals.

[0077] The PID control unit has built-in proportional, integral, and differential operation modules. It generates a control quantity u(t) according to the deviation e(t) and transmits it to the DCS. The DCS sends a 4-20 mA control signal to the drive module, which is converted into an actual air pressure value to adjust the oscillation amplitude of the motor, and finally inputs it to the oscillation motor of the activated coal feeder.

[0078] The above-mentioned units are connected through the existing industrial Ethernet and analog signal links in the power plant to form a closed-loop control loop.

[0079] Embodiment 3

[0080] Based on the foregoing embodiment, refer to Figure 3 , this embodiment provides an electronic device, which is characterized in that it includes: one or more processors and a memory. The memory stores one or more programs, and the one or more programs include instructions for executing the method for adjusting the output of the Euro bin activated coal feeder based on PID control in Embodiment 1.

[0081] As Figure 2 described, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the above Figure 1 described method. Of course, in addition to the software implementation method, the present invention does not exclude other implementation methods, such as logical devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logical unit, and can also be hardware or logical devices.

[0082] The memory may include non-permanent memory in the form of computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory is an example of computer-readable media.

[0083] Embodiment 4

[0084] Based on the foregoing embodiments, this embodiment provides a computer-readable storage medium, including one or more programs for execution by one or more processors of an electronic device, the one or more programs including instructions for performing the method for regulating the output of the Eurobin activation coal feeder based on PID control as described in Embodiment 1.

[0085] Computer-readable media includes both permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0086] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for regulating the output of a Euro bin activation coal feeder based on PID control, characterized in that, It includes the following steps: Step S1: Obtain a preset target coal flow rate as the reference input n(t) of the PID control system; Step S2: Real-time collect the actual coal flow rate y(t) of the activation feeder of the Euro bin through an electronic scale; Step S3: Calculate the deviation e(t) between the reference input n(t) and the actual coal flow rate y(t), where e(t) = n(t) - y(t); Step S4: Use a PID controller to perform proportional, integral, and derivative adjustments on the deviation e(t) to obtain the control quantity u(t): Step S5: Adjust the output of the activation feeder according to the control quantity u(t), and control the coal flow rate by changing the air pressure of the vibration motor; Step S6: Repeat steps S2 - S5 to form a closed-loop control process until the actual coal flow rate y(t) stabilizes at the target coal flow rate n(t). Among them, in the said step S4, the output expression of the PID controller is: Among them, K p is the proportionality coefficient, T i is the integral time constant, T d is the differential time constant.

2. The output regulation method of the Euro bin activation coal feeder based on PID control according to claim 1, characterized in that, It also includes: Step S7, in response to u(t) > u max and the duration exceeding the threshold, it is determined that there is a blockage in the activated coal feeder, and an alarm signal is sent, where u max is the maximum power output of the preset activated coal feeder.

3. A method for regulating the output of an Eulo bin activation coal feeder based on PID control according to claim 1, characterized in that, In the described step S4, through the proportionality coefficient K p amplify or reduce the deviation in real time. The integral adjustment link eliminates the static error by accumulating the historical deviation, and the differential adjustment link suppresses the flow fluctuation by predicting the deviation change rate.

4. A method for regulating the output of an Oulo warehouse activation coal feeder based on PID control according to claim 1, characterized in that, The parameters K p 、T i 、T d of the described PID controller are determined by on-site working condition debugging based on the influence of the degree of coal accumulation and the viscosity of coal quality on the coal flow rate.

5. A regulating system for the output of an Oulo bin activation coal feeder based on PID control, characterized in that, It includes: A target setting unit for presetting the target coal flow rate and outputting the reference input n(t); A flow rate collection unit including an electronic scale for real-time collecting the actual coal flow rate y(t) of the activation feeder; A deviation calculation unit for calculating the deviation e(t) between the reference input n(t) and the actual flow rate y(t); A PID control unit with built-in proportional, integral, and derivative operation modules, which generates the control quantity u(t) according to the deviation e(t). The output expression of the PID control unit is: where K p is the proportionality coefficient, T i is the integral time constant, T a is the derivative time constant; An execution unit including the activation feeder and its vibration motor air pressure adjustment module for adjusting the output and controlling the coal flow rate according to the control quantity u(t); Among them, the target setting unit, the flow rate collection unit, the deviation calculation unit, the PID control unit, and the execution unit are connected in sequence to form a closed-loop control system.

6. The output regulation system of the Euro bin activation coal feeder based on PID control according to claim 5, characterized in that, The said flow rate collection unit is electrically connected to the PID control unit, and feeds back the real-time flow rate signal to the PID control unit as the input of the closed-loop control.

7. The output regulation system of the Euro bin activation coal feeder based on PID control according to claim 5, characterized in that, Through the proportionality coefficient K p The deviation is amplified or reduced in real time. The integral regulation link eliminates the static error by accumulating the historical deviation, and the derivative regulation link suppresses the flow fluctuation by predicting the deviation change rate.

8. A regulating system for the output of an Oulo bin activation coal feeder based on PID control according to claim 5, characterized in that, The parameters K p and T i and T d of the described PID controller are determined by on-site working condition debugging based on the influence of the degree of coal accumulation and coal quality viscosity on the coal flow rate.

9. An electronic device, characterized in that, It includes: One or more processors and a memory. The memory stores one or more programs, and the one or more programs include instructions for executing the method for adjusting the output of the activation feeder of the Euro bin based on PID control as described in any one of claims 1 - 4.

10. A computer-readable storage medium, characterized in that, It includes one or more programs for execution by one or more processors of an electronic device. The one or more programs include instructions for executing the method for adjusting the output of the activation feeder of the Euro bin based on PID control as described in any one of claims 1 - 4.

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