A method, system, device and medium for proportional relief valve control of a coal mill

Abstract

The application discloses a coal mill proportional overflow valve control method, system, equipment and medium, and belongs to the technical field of the coal mill. The coal mill proportional overflow valve control method comprises the following steps: controlling the proportional overflow valve to perform parameter initialization self-correction operation to obtain a working curve; inputting current production data into an optimization matrix to obtain a target variable loading oil pressure; calculating a target proportional overflow valve instruction corresponding to the target variable loading oil pressure through the working curve; controlling the proportional overflow valve to execute corresponding actions according to the target proportional overflow valve instruction, and detecting an actual variable loading oil pressure of the coal mill; judging whether a corresponding relationship between the target proportional overflow valve instruction and the actual variable loading oil pressure conforms to the working curve; and if not, updating the working curve according to the corresponding relationship between the target proportional overflow valve instruction and the actual variable loading oil pressure. The application can automatically correct the working curve of the proportional overflow valve and improve the control precision of the proportional overflow valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mills, in particular to a proportional overflow valve control method, system, device and medium for a coal mill. BACKGROUND

[0002] The key component in the variable load hydraulic control system of the coal mill is the proportional overflow valve, which is directly related to the economy of the operation of the coal mill. The proportional overflow valve is controlled by the external DCS (Distributed Control System) instruction to give a 4-20mA signal to the signal amplifier of the proportional overflow valve, which is processed by the signal amplifier and sent to the proportional electromagnet. The proportional electromagnet pushes the cone valve core to have an opening corresponding to the input signal, so as to obtain the corresponding pilot pressure, which controls the main valve core to adjust the pressure of the system. The proportional overflow valve is provided with a built-in pressure sensor to detect the actual pressure of the system, so as to realize closed-loop control of the pressure in the valve and control the entire pressure regulating system.

[0003] In long-term operation, the performance decay or mechanical wear of the electrical components of the proportional overflow valve may cause linear mismatch or linear difference of the entire proportional overflow valve. In this case, the working curve of the proportional valve needs to be optimized or corrected. In the related art, the new working curve needs to be written into the proportional overflow valve by the staff through the computer, which is a relatively cumbersome process.

[0004] Therefore, how to automatically correct the working curve of the proportional overflow valve and improve the control accuracy of the proportional overflow valve is a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide a proportional overflow valve control method, system, device and medium for a coal mill, which can automatically correct the working curve of the proportional overflow valve and improve the control accuracy of the proportional overflow valve.

[0006] To solve the above technical problems, the present application provides a proportional overflow valve control method for a coal mill, which is applied to a distributed control system, wherein the distributed control system is connected with a proportional overflow valve through a voltage controller. The proportional overflow valve control method for the coal mill comprises the following steps:

[0007] controlling the proportional overflow valve to perform parameter initialization self-correction operation to obtain a working curve; wherein the working curve is used to describe the corresponding relationship between the proportional overflow valve instruction and the variable load oil pressure;

[0008] Obtaining current production data of the coal mill, and inputting the current production data into an optimization matrix to obtain a target variable load oil pressure; wherein the optimization matrix is a matrix established by a dynamic matrix control algorithm, and the optimization matrix is used to describe a corresponding relationship between production data and a variable load oil pressure;

[0009] Calculating a target proportional overflow valve instruction corresponding to the target variable load oil pressure through the working curve;

[0010] Controlling the proportional overflow valve to perform corresponding actions according to the target proportional overflow valve instruction, and detecting an actual variable load oil pressure of the coal mill;

[0011] Judging whether a corresponding relationship between the target proportional overflow valve instruction and the actual variable load oil pressure conforms to the working curve;

[0012] If not, updating the working curve according to the corresponding relationship between the target proportional overflow valve instruction and the actual variable load oil pressure, so as to control the proportional overflow valve by using a new working curve.

[0013] Optionally, the proportional overflow valve is controlled to perform a parameter initialization self-correction operation to obtain a working curve, comprising:

[0014] Constructing an instruction set; wherein the instruction set contains multiple alternative proportional overflow valve instructions, and instruction parameter values corresponding to any two alternative proportional overflow valve instructions are different; wherein the instruction parameter value is a current value or a voltage value;

[0015] Selecting an alternative proportional overflow valve instruction from the instruction set according to an order from low to high of instruction parameter values to control the proportional overflow valve, and recording a variable load oil pressure to obtain a first oil pressure set;

[0016] Selecting an alternative proportional overflow valve instruction from the instruction set according to an order from high to low of instruction parameter values to control the proportional overflow valve, and recording a variable load oil pressure to obtain a second oil pressure set;

[0017] Judging whether variable load oil pressures corresponding to a same alternative proportional overflow valve instruction in the first oil pressure set and the second oil pressure set are the same;

[0018] If yes, establishing the working curve according to a corresponding relationship between the alternative proportional overflow valve instruction and the variable load oil pressure in the first oil pressure set.

[0019] Optionally, after judging whether variable load oil pressures corresponding to a same alternative proportional overflow valve instruction in the first oil pressure set and the second oil pressure set are the same, the method further comprises:

[0020] If the variable loading oil pressure corresponding to the same alternative proportional relief valve instruction in the first oil pressure set and the second oil pressure set is different, the cycle number is updated, and whether the cycle number is greater than a preset value is determined;

[0021] If yes, it is determined that the proportional relief valve has a fault;

[0022] If no, a step of selecting an alternative proportional relief valve instruction from the instruction set in order from low to high according to the instruction parameter value to control the proportional relief valve is entered.

[0023] Optionally, before the target variable loading oil pressure is obtained by inputting the current production data into the optimization matrix, the following steps are further included:

[0024] Obtaining historical production data of the coal mill; wherein, the historical production data includes any one or a combination of any several of the following: coal mill current, coal mill coal quantity, coal mill inlet air pressure, coal mill outlet air pressure, and coal mill vibration data;

[0025] Training a prediction model using the corresponding relationship between the historical production data and the historical variable loading oil pressure, and constructing the optimization matrix corresponding to the prediction model through a dynamic matrix control algorithm.

[0026] Optionally, obtaining the historical production data of the coal mill includes:

[0027] Obtaining the historical production data of the coal mill under various working conditions from the device log;

[0028] Correspondingly, before training the prediction model using the corresponding relationship between the historical production data and the historical variable loading oil pressure, the following steps are further included:

[0029] Obtaining the historical variable loading oil pressure corresponding to each historical production data from the device log.

[0030] Optionally, the following steps are further included:

[0031] Obtaining a variation trend of instruction parameter values corresponding to the proportional relief valve instructions issued in the last n times; wherein, the instruction parameter value is a current value or a voltage value;

[0032] Obtaining an oil pressure variation trend corresponding to the actual variable loading oil pressure detected in the last n times;

[0033] Determining whether the variation trend of the instruction parameter values is consistent with the oil pressure variation trend;

[0034] If no, it is determined that the proportional relief valve has a fault.

[0035] Optionally, after it is determined that the proportional relief valve has a fault, the following steps are further included:

[0036] acquire a reference proportional overflow valve instruction; wherein the reference proportional overflow valve instruction is a proportional overflow valve instruction with the largest instruction parameter value among the last m issued proportional overflow valve instructions;

[0037] control the proportional overflow valve to perform corresponding actions according to the reference proportional overflow valve instruction.

[0038] The application further provides a proportional overflow valve control system of a coal mill, which is applied to a distributed control system connected with a proportional overflow valve through a voltage controller, and comprises:

[0039] an initialization module configured to control the proportional overflow valve to perform parameter initialization self-correction operation and obtain a working curve; wherein the working curve is used to describe the corresponding relationship between a proportional overflow valve instruction and a variable loading oil pressure;

[0040] a target oil pressure determination module configured to acquire current production data of the coal mill and input the current production data into an optimization matrix to obtain a target variable loading oil pressure; wherein the optimization matrix is a matrix established through a dynamic matrix control algorithm, and is used to describe the corresponding relationship between production data and a variable loading oil pressure;

[0041] an instruction determination module configured to calculate a target proportional overflow valve instruction corresponding to the target variable loading oil pressure through the working curve;

[0042] a control module configured to control the proportional overflow valve to perform corresponding actions according to the target proportional overflow valve instruction, and detect an actual variable loading oil pressure of the coal mill;

[0043] a judgment module configured to judge whether the corresponding relationship between the target proportional overflow valve instruction and the actual variable loading oil pressure conforms to the working curve, and further configured to update the working curve according to the corresponding relationship between the target proportional overflow valve instruction and the actual variable loading oil pressure if the corresponding relationship does not conform to the working curve, so as to control the proportional overflow valve by using the new working curve.

[0044] The application further provides a storage medium having a computer program stored thereon, wherein the computer program is configured to implement the steps of the proportional overflow valve control method of the coal mill.

[0045] The application further provides an electronic device comprising a memory and a processor, wherein the memory has a computer program stored therein, and the processor is configured to implement the steps of the proportional overflow valve control method of the coal mill when calling the computer program in the memory.

[0046] This application provides a proportional relief valve control method for a coal mill. This method is applied to a distributed control system, which is connected to the proportional relief valve via a voltage controller. This application obtains the relationship between the proportional relief valve command and the variable load oil pressure through parameter initialization and self-calibration, representing it as a working curve. This application uses current production data and an optimization matrix to predict the target variable load oil pressure and determines the proportional relief valve command corresponding to the target variable load oil pressure from the working curve. Based on the obtained proportional relief valve command, this application controls the proportional relief valve according to the target proportional relief valve command and monitors the actual variable load oil pressure. When the correspondence between the target proportional relief valve command and the actual variable load oil pressure does not conform to the working curve, the working curve can be updated to control the proportional relief valve using the new working curve. The above-mentioned process of updating the working curve is implemented in the distributed control system. As the coal mill operating conditions change, the working curve can be dynamically adjusted to reflect the actual characteristics of the proportional relief valve. Therefore, this application can automatically correct the working curve of the proportional relief valve, improving the control accuracy of the proportional relief valve. This application also provides a proportional overflow valve control system for a coal mill, a storage medium, and an electronic device, which have the aforementioned beneficial effects, and will not be elaborated further here. Attached Figure Description

[0047] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A flowchart of a proportional overflow valve control method for a coal mill provided in this application embodiment;

[0049] Figure 2 This is a schematic diagram of the control circuit of a proportional relief valve in related technologies;

[0050] Figure 3 A schematic diagram of the control circuit of a proportional relief valve provided in an embodiment of this application;

[0051] Figure 4 A flowchart of a proportional relief valve parameter self-calibration control method provided in this application embodiment;

[0052] Figure 5 A flowchart of parameter initialization self-calibration provided in an embodiment of this application;

[0053] Figure 6 This is a flowchart of a proportional relief valve parameter self-calibration control method provided in an embodiment of this application. Detailed Implementation

[0054] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0055] Please see the following Figure 1 , Figure 1 A flow chart of a proportional overflow valve control method of a coal mill provided by the embodiments of the present application.

[0056] The specific steps can include:

[0057] S101: controlling the proportional overflow valve to perform parameter initialization self-correction operation to obtain a working curve;

[0058] In the embodiments, the proportional overflow valve can be applied to a distributed control system. The distributed control system is connected with the proportional overflow valve through a voltage controller. The distributed control system is used to realize setting and updating of the working curve. In the related art, the proportional overflow valve includes a proportional overflow valve controller, an electromagnet and a valve core. The working curve setting function is realized by the proportional overflow valve controller. In the embodiments, the working curve setting function is moved to the distributed control system. The distributed control system is connected with the voltage controller. The voltage controller is connected with the electromagnet of the proportional overflow valve. The voltage controller controls the input voltage of the electromagnet according to the proportional overflow valve instruction of the distributed control system. After the input voltage on the electromagnet changes, the thrust of the electromagnet on the valve core also changes, so that the continuously changing hydraulic pressure is obtained.

[0059] In the proportional overflow valve of the coal mill, the working curve is used to describe the corresponding relationship between the proportional overflow valve instruction and the variable load oil pressure. The working curve obtained by the parameter initialization self-correction operation can reflect the actual load oil pressure of the proportional overflow valve under different instructions, so as to ensure that the control system can accurately generate the corresponding proportional overflow valve instruction according to the target variable load oil pressure.

[0060] The embodiment can directly read the configuration parameters from the configuration file, set the working curve based on the configuration parameters, and implement the parameter initialization self-correction operation. The embodiment can also input a plurality of alternative proportional overflow valve instructions, and generate the working curve according to the corresponding relationship between the alternative proportional overflow valve instructions and the variable loading oil pressure. In the embodiment, the proportional overflow valve instruction is usually in the form of an electrical signal, which can be an instruction parameter value. The instruction parameter value is a current value or a voltage value. Specifically, the proportional overflow valve instruction is in the form of an instruction parameter value, that is, the opening of the valve is adjusted by changing the size of the current or voltage, and then the pressure or flow of the system is controlled.

[0061] S102: Obtain current production data of the coal mill, and input the current production data into an optimization matrix to obtain a target variable loading oil pressure;

[0062] In the embodiment, the current production data of the coal mill can be collected by various sensors. The current production data is the production data at the current time or the current period. The production data includes any one or a combination of the coal mill current, the coal mill coal quantity, the coal mill inlet air pressure, the coal mill outlet air pressure, and the coal mill vibration data.

[0063] In the embodiment, the optimization matrix can be established in advance by using historical data. The optimization matrix is a matrix established by a dynamic matrix control algorithm, and is used to describe the corresponding relationship between the production data and the variable loading oil pressure. After the current production data is obtained, the current production data can be input into the optimization matrix to obtain the target variable loading oil pressure, that is, the optimization matrix is used to calculate the target variable loading oil pressure corresponding to the current production data. The target variable loading oil pressure is the variable loading oil pressure required by the coal mill.

[0064] The construction process of the above optimization matrix is as follows: collect historical production data, including coal mill current, coal mill coal quantity, coal mill inlet air pressure, coal mill outlet air pressure, coal mill vibration, etc., and the corresponding variable load oil pressure value. This embodiment can use these historical data to train a prediction model that can predict future variable load oil pressure according to current production data. The training method of the above prediction model includes multiple linear regression, support vector machine or neural network, etc. Based on the trained prediction model, an optimization problem is constructed. The goal of the optimization problem is to minimize the prediction error or meet specific control objectives (such as keeping the coal mill in energy-saving operation), while considering operating constraints (such as maximum and minimum opening limits of the valve). The dynamic matrix control algorithm is used to solve the above optimization problem. The dynamic matrix control algorithm is a model-based predictive control method that considers the dynamic characteristics of the system, the uncertainty of the prediction model and the operating constraints to determine the optimal control sequence for a future period of time. The optimal control sequence obtained after solving the optimization problem can be regarded as part of the optimization matrix. The optimization matrix contains the optimal variable load oil pressure command sequence for a future period of time, which will guide the control action of the proportional overflow valve.

[0065] S103: Calculate the target proportional overflow valve command corresponding to the target variable load oil pressure through the working curve;

[0066] Wherein: after obtaining the target variable load oil pressure, the target variable load oil pressure can be substituted into the working curve to obtain the corresponding proportional overflow valve command, i.e. the target proportional overflow valve command.

[0067] S104: Control the proportional overflow valve to perform corresponding actions according to the target proportional overflow valve command, and detect the actual variable load oil pressure of the coal mill;

[0068] Wherein, the target proportional overflow valve command is the target current value or target voltage value calculated through the working curve, and the control system sends the target proportional overflow valve command corresponding control signal to the proportional overflow valve. This control signal usually takes the form of an electrical signal, such as current value or voltage value, which determines the opening of the proportional overflow valve and thus controls the size of the load oil pressure. After receiving the control signal, the proportional overflow valve performs corresponding actions according to the command, adjusts the valve opening, and then controls the load oil pressure to reach the target value.

[0069] In order to ensure the control effect, this embodiment can also monitor the actual variable load oil pressure. This is usually done through a pressure sensor installed in the coal mill, which converts the actual variable load oil pressure value into an electrical signal for feedback.

[0070] S105: Determine whether the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure conforms to the working curve; if yes, end the process; if no, proceed to step S106.

[0071] In this embodiment, the target variable loading oil pressure corresponding to the target proportional overflow valve instruction can be queried according to the working curve. If the difference between the target variable loading oil pressure and the actual variable loading oil pressure is not within the first preset interval, it is determined that the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure does not conform to the working curve.

[0072] In this embodiment, the proportional overflow valve instruction corresponding to the actual variable loading oil pressure can also be queried according to the working curve. If the current difference or voltage difference between the proportional overflow valve instruction corresponding to the actual variable loading oil pressure and the target proportional overflow valve instruction is not within the second preset interval, it is determined that the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure does not conform to the working curve.

[0073] In this embodiment, it can also be determined whether the ratio of the target proportional overflow valve instruction to the actual variable loading oil pressure conforms to the working curve.

[0074] S106: Update the working curve according to the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure, so as to control the proportional overflow valve by using the new working curve.

[0075] In this embodiment, the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure does not conform to the working curve. Then, the working curve can be updated according to the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure, to obtain a new working curve. The new working curve conforms to the correspondence between the target proportional overflow valve instruction and the actual variable loading oil pressure. In this embodiment, the difference between the target variable loading oil pressure and the actual variable loading oil pressure can be compared, and the position of the corresponding point on the working curve can be adjusted according to the difference, so that the working curve more accurately reflects the relationship between the proportional overflow valve instruction and the actual variable loading oil pressure.

[0076] The operations of S101-S106 described above can be performed in various situations, for example, the operations of S101-S106 can be performed after receiving a manual forced execution instruction issued by a user, or the operations of S101-S106 can be performed at intervals of a preset time length. At other times when S101-S106 is not performed, the proportional overflow valve can be directly controlled by using the working curve obtained last time.

[0077] The embodiment is applied to a distributed control system connected with a proportional relief valve through a voltage controller. The embodiment can obtain the relationship between the proportional relief valve instruction and the variable load oil pressure and express it as a working curve through parameter initialization self-correction operation. The embodiment uses current production data and an optimization matrix to predict the target variable load oil pressure and determine the proportional relief valve instruction corresponding to the target variable load oil pressure from the working curve. On the basis of the proportional relief valve instruction, the embodiment controls the proportional relief valve according to the target proportional relief valve instruction and monitors the actual variable load oil pressure. When the corresponding relationship between the target proportional relief valve instruction and the actual variable load oil pressure does not conform to the working curve, the working curve can be updated so as to control the proportional relief valve by using the new working curve. The above process of updating the working curve is implemented in the distributed control system. With the change of the operating conditions of the coal mill, the working curve can be dynamically adjusted to reflect the actual characteristics of the proportional relief valve. Therefore, the embodiment can automatically correct the working curve of the proportional relief valve and improve the control accuracy of the proportional relief valve.

[0078] As a feasible implementation, the embodiment can obtain the working curve of the proportional relief valve through parameter initialization self-correction in the following manner:

[0079] Step A1: constructing an instruction set;

[0080] The instruction set contains multiple alternative proportional relief valve instructions, any two of which have different instruction parameter values, which are current values or voltage values. Taking the current value as an example, they can be 4 mA, 6 mA, 8 mA, …, 20 mA.

[0081] Step A2: selecting alternative proportional relief valve instructions from the instruction set in the order from low to high according to the instruction parameter values to control the proportional relief valve and recording the variable load oil pressure to obtain a first oil pressure set;

[0082] The first oil pressure set includes the variable load oil pressure corresponding to each alternative proportional relief valve instruction selected in the order from low to high.

[0083] Specifically, the embodiment can control the proportional relief valve in turn according to the alternative proportional relief valve instructions sorted in the order from low to high, using only one alternative proportional relief valve instruction each time. For each alternative proportional relief valve instruction, the corresponding variable load oil pressure value is recorded, and all the recorded variable load oil pressure values are collected to form the first oil pressure set.

[0084] Step A3: selecting alternative proportional relief valve instructions from the instruction set in the order from high to low according to the instruction parameter values to control the proportional relief valve and recording the variable load oil pressure to obtain a second oil pressure set;

[0085] The second oil pressure set comprises: from high to low, each selected proportional relief valve instruction corresponding to the variable loading oil pressure in the selected proportional relief valve instruction process.

[0086] Specifically, the embodiment can control the proportional relief valve in turn according to the selected proportional relief valve instruction sorted from high to low, and use only one selected proportional relief valve instruction each time. For each selected proportional relief valve instruction, the corresponding variable loading oil pressure value is recorded, and all recorded variable loading oil pressure values are collected to form the second oil pressure set.

[0087] Step A4: determining whether the variable loading oil pressure corresponding to the same selected proportional relief valve instruction in the first oil pressure set and the second oil pressure set is the same; if yes, entering step A5; if no, entering step A6.

[0088] In the embodiment, the variable loading oil pressure values corresponding to the same selected proportional relief valve instruction in the first oil pressure set and the second oil pressure set can be searched respectively. If the variable loading oil pressure values corresponding to the same selected proportional relief valve instruction in the two sets are the same, it is considered consistent; if not the same, it is considered inconsistent.

[0089] If the variable loading oil pressure corresponding to the same selected proportional relief valve instruction in the first oil pressure set and the second oil pressure set is the same, step A5 can be entered; if the variable loading oil pressure corresponding to the same selected proportional relief valve instruction in the first oil pressure set and the second oil pressure set is not the same, step A6 can be entered.

[0090] Step A5: establishing the working curve according to the corresponding relationship between the selected proportional relief valve instruction and the variable loading oil pressure in the first oil pressure set.

[0091] Step A6: updating the cycle number and determining whether the cycle number is greater than a preset value; if yes (i.e., the cycle number is greater than the preset value), it is determined that the proportional relief valve has a fault, and an alarm is given to the maintenance personnel or the operator for replacement, without the need for retesting; if no (i.e., the cycle number is less than or equal to the preset value), step A2 is entered for retesting.

[0092] As a feasible implementation manner, before the target variable loading oil pressure is obtained by inputting the current production data into the optimization matrix, the optimization matrix can also be constructed by the following method:

[0093] Step B1: obtaining historical production data of the coal mill;

[0094] The historical production data comprises any one or a combination of the following: the coal mill current, the coal mill coal quantity, the coal mill inlet air pressure, the coal mill outlet air pressure, and the coal mill vibration data.

[0095] Specifically, the embodiment can obtain the historical production data of the coal mill under various working conditions from the device log.

[0096] Step B2: training a prediction model using the historical production data and the corresponding relationship between the historical variable hydraulic pressure.

[0097] Before training the prediction model using the historical production data and the corresponding relationship between the historical variable hydraulic pressure, the historical variable hydraulic pressure corresponding to each historical production data can also be obtained from the device log.

[0098] Specifically, the embodiment can use a machine learning method (such as linear regression, support vector machine, or neural network) to train the prediction model, which can predict the optimal variable hydraulic pressure according to the current production data.

[0099] Step B3: constructing the optimization matrix corresponding to the prediction model through a dynamic matrix control algorithm.

[0100] The embodiment can use a dynamic matrix control (DMC) algorithm to integrate the trained prediction model into the DMC framework. The DMC algorithm considers the output of the prediction model, the operation constraint conditions (such as maximum / minimum control action limit, variable range, etc.), and the optimization target (such as minimizing error, maximizing yield, etc.), and constructs an optimization matrix by solving an optimization problem. The optimization matrix describes the optimal variable hydraulic pressure instruction sequence in the future period of time, which can make the coal mill reach the optimal operating state under the current production conditions.

[0101] As a feasible implementation, whether the proportional overflow valve is faulty can also be determined by the following method: obtaining the instruction parameter value change trend corresponding to the proportional overflow valve instruction issued in the last n times; obtaining the oil pressure change trend corresponding to the actual variable hydraulic pressure detected in the last n times; determining whether the instruction parameter value change trend is consistent with the oil pressure change trend; if not, it is determined that the proportional overflow valve is faulty. The instruction parameter value is a current value or a voltage value.

[0102] As a feasible implementation, after determining that the proportional overflow valve is faulty, a reference proportional overflow valve instruction can also be obtained; the reference proportional overflow valve instruction is the proportional overflow valve instruction with the largest instruction parameter value among the proportional overflow valve instructions issued in the last m times; and the proportional overflow valve is controlled to perform corresponding actions according to the reference proportional overflow valve instruction. Through the above method, the coal mill can be prevented from being blocked.

[0103] The above-described process is illustrated by the following examples in actual applications.

[0104] The principle of proportional relief valve mainly involves the use of the thrust generated by an electromagnet to control the action of the valve core, thereby achieving continuous control of pressure and flow in the hydraulic system. The proportional relief valve is composed of a DC proportional electromagnet and a hydraulic valve. The DC proportional electromagnet used in the proportional relief valve is different from the electromagnet used in general electromagnetic valves. The use of a proportional electromagnet can obtain displacement output and suction output proportional to the given current. Proportional relief valves can be divided into three categories: proportional pressure valves, proportional flow valves, and proportional directional valves, according to their control parameters.

[0105] The direct-acting relief valve relies on the pressure oil in the system acting directly on the valve core to balance the spring force, to control the opening and closing action of the valve core. When the inlet pressure is small, the valve core is in the lower end position under the action of the pressure spring, separating the inlet and return ports. When the oil pressure rises, the force generated at the lower end of the valve core exceeds the compression force of the spring, and the valve core rises, opening the valve port and returning the excess oil to the tank.

[0106] The pilot relief valve is composed of a pilot valve and a main valve. The difference in pressure between the left and right ends of the main valve core is used to balance the spring force to control the movement of the valve core. When the system pressure rises and is greater than the set pressure of the pilot valve spring, the pilot valve opens, and the pressure oil in the right cavity of the main valve core flows back to the tank through the spool and small hole. Due to the pressure drop caused by the damping hole of the upper valve core, the pressure in the right cavity of the valve core is lower than that in the left cavity. When the pressure difference between the left and right ends of the valve core exceeds the action of the spring, the valve core is pushed to the right, the inlet and return cavities are connected, and the overflow function is realized.

[0107] The working principle of the proportional relief valve is to change the overflow pressure by changing the spring force. The force exerted by the proportional electromagnet on the spring can be adjusted in proportion, so the pressure of the proportional relief valve will change in proportion to the input signal. Like the proportional relief valve, the ordinary relief valve also has a valve core. However, the ordinary relief valve adjusts the hydraulic pressure by adjusting the spring force, while the proportional relief valve directly generates thrust on the valve core through the electromagnet. The input voltage on the electromagnet can be varied between 0-24 volts, and the resulting thrust will change accordingly, thereby obtaining a continuously variable hydraulic pressure.

[0108] In summary, the proportional relief valve achieves precise control of pressure and flow in the hydraulic system through the control of the electromagnet. Its working principle involves two basic structural forms: direct-acting and pilot relief valves, and the use of electronic components and proportional electromagnets to achieve continuous regulation of system pressure.

[0109] The proportional relief valve is a widely used component in hydraulic systems. Its function is to regulate the flow of hydraulic energy within the system to control the actuator. In the operation of the coal mill, the proportional relief valve can control the flow and pressure of hydraulic oil, effectively controlling the load of the coal mill. In addition, the proportional relief valve can also alleviate the pressure fluctuations in the hydraulic system, effectively protecting the safe operation of the hydraulic system and other components. When the proportional relief valve works, the flow of fluid is controlled by the internal throttle device, so that the relationship between flow and pressure at different opening sizes becomes a certain proportion. The opening size of the proportional relief valve is controlled by the proportional solenoid valve, and the control signal of the proportional relief valve can be controlled by a microprocessor such as PLC.

[0110] In the long-term operation, due to the performance degradation of the electrical components of the proportional relief valve or due to mechanical wear and other problems, the entire proportional relief valve may not match or have a linear difference. In this case, the linear (i.e. working curve) of the proportional valve needs to be corrected. In the related art, the working curve is corrected by reading the proportional relief valve electric control device using special software. The original design requires a notebook computer to install software to write device hardware data through communication, which is relatively complex. The original design control circuit is shown in Figure 2 Figure 2 The control circuit principle of the proportional relief valve in the related art. The coal mill can convert the coal quantity of the coal feeder into a DCS control signal (such as a 4~20mA signal), and the DCS control signal is input into the proportional relief valve controller to control the electromagnet and the valve core to control the oil pressure. The proportional relief valve in the above related art is an integrated structure of the proportional relief valve controller, the electromagnet and the valve core. The integrated device receives the DCS signal on site, and the device needs to receive the DCS signal to control the oil pressure. The integrated device has high integration.

[0111] The proportional relief valve failure will result in the following results: (1) the proportional valve linear difference problem, which causes the coal mill output to be unstable, the vibration is large, and the normal operation of the coal mill is affected; (2) the proportional valve is abnormal, the coal fineness of the coal mill is uneven, which affects the energy saving output of the coal mill and increases the equipment output; (3) the proportional valve is abnormal, which accelerates the wear of the grinding roller and the grinding disc, accelerates the wear of the coal mill, and causes more equipment operation failures. As can be seen, the method of correcting the working curve in the related art is to set the software curve of the proportional relief valve internal control test, which must be stopped and the software parameters are set to complete the curve correction to overcome the influence of equipment failure and wear.

[0112] In view of the defects in the above related art, the control logic and parameter setting part of the proportional relief valve are moved from the on-site integrated proportional relief valve to the DCS for control, and the related logic design and function are realized in the DCS. Please refer to Figure 3 Figure 3 ​​The control circuit principle of the proportional overflow valve provided in the embodiment of the application is as follows: in the scheme, the control logic part and the electromagnet voltage control part are separated from the original design. Under the DCS control logic, the DCS control signal (such as a 4-20 mA signal) is input into the voltage controller, and then the electromagnet and the valve core are controlled so as to control the oil pressure. The proportional overflow valve of the related art is controlled by using a split structure. In the embodiment, the split structure is to keep the electromagnet and the valve core as two integrated elements, and the voltage controller is separated, so that the electrical control part and the mechanical part are separated, which is beneficial to equipment testing, maintenance and maintenance. The electromagnet and the valve core are integrated and cannot be separated, and the control oil pressure is the final controlled process parameter and does not belong to a part of the proportional overflow valve. The original logic of the proportional overflow valve control is executed by the DCS in the embodiment, and is not executed in the self-contained program. After the program control function is separated in the embodiment, only a voltage controller is needed, and the electromagnet valve core is controlled according to the DCS control instruction, so that the control oil pressure reaches the optimal value.

[0113] The DCS configuration logic is convenient for technicians to adjust the configuration, can be observed and adjusted in real time when the coal mill is normally operated, is convenient for maintenance, makes the proportional overflow valve more suitable for the coal mill, improves the economy, and optimizes the energy saving index. The DCS proportional overflow valve setting parameter realizes self-correction control, real-time collection of field process data, automatic correction of parameters, and optimal setting. The controller split design can arrange the control elements of the proportional overflow valve in a split manner, and the proportional overflow valve is convenient for maintenance and replacement after failure, and the maintenance cost is reduced.

[0114] Please refer to Figure 4 , Figure 4 The flowchart of the proportional overflow valve parameter self-correction control method provided in the embodiment of the application is as follows: a new electromagnet valve is installed, a DCS control signal is obtained according to the DCS control logic, and the DCS control signal is input into a control device. The DCS control logic is as follows: parameter initialization self-correction, initial control parameters (that is, parameters of a working curve) are obtained, and an index is evaluated; if the evaluation is abnormal, the control parameters are optimized, and the optimized control parameters are calculated in real time; and if the evaluation is normal, the parameters are output.

[0115] The embodiment provides Figure 4 The DCS control logic shown in the figure is used to realize self-control of the coal mill variable load pressure by using a self-parameter control logic.

[0116] Specifically, when the coal mill is stopped, the electromagnet control valve body can be installed, and the coal mill loading oil system has normal working conditions.

[0117] The parameter initialization and self-calibration process is as follows: The coal mill loading oil system is started, the self-calibration program is initiated, and initial parameter data is automatically obtained through testing, establishing an initial functional relationship between the proportional relief valve command and the variable loading oil pressure. This relationship ultimately determines the specific variable loading oil pressure values ​​corresponding to the 4 / 6 / 8 / 10 mA proportional relief valve commands, which can be used to form an instruction set. Using a dynamic optimization matrix method, this embodiment can calculate the target loading oil pressure. This embodiment can utilize the previously determined functional relationship to back-calculate the target loading oil pressure into the corresponding proportional relief valve command, output this proportional relief valve command, and thus control the proportional relief valve, ensuring that the actual variable loading oil pressure reaches the expected target value.

[0118] The evaluation process is as follows: After starting the pulverizing system and putting the coal mill into operation, a coal mill status evaluation is conducted. The main indicators include: coal mill current, coal mill feed rate, coal mill inlet air pressure, coal mill outlet air pressure, and coal mill vibration. These indicators, along with the coal feeder feed rate, proportional relief valve command, and loading oil pressure, constitute a parameter self-calibration control loop. This loop automatically selects the most suitable proportional relief valve command based on current data. When the characteristics of the proportional relief valve change, the self-calibration loop can also self-calibrate its working function curve to always maintain the loading oil pressure under the optimal operating conditions of the coal mill. When the indicator evaluation is normal, the parameters of the working curve remain unchanged. When the indicator evaluation is abnormal (equipment failure, proportional relief valve jamming, poor linearity, etc.), the functional relationship between the proportional relief valve control command and the coal mill loading oil will change, requiring correction calculation by the self-calibration loop. The problem is that the parameter model self-calibrates the proportional relief valve command to keep the loading oil pressure within the optimal operating range of the system.

[0119] The self-calibrating control loop ultimately outputs a proportional relief valve control command, i.e., an output parameter, which controls the loading of oil into the coal mill.

[0120] The purpose of parameter initialization self-calibration is to obtain the working curve (i.e., working characteristic curve) of the new electromagnet and valve core in the loading oil system, and to assign the working curve the first value before the new equipment is put into use.

[0121] Please see Figure 5 , Figure 5The flow chart of the parameter initialization self-correction provided by the embodiment of the application has a process including: starting the parameter initialization self-correction program, issuing a 4mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value, issuing a 6mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value,..., issuing a 20mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value, issuing an 18mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value, issuing a 16mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value,..., and issuing a 4mA instruction of the proportional relief valve and recording a variable loading oil pressure feedback value. The variable loading oil pressure is compared with the current loading oil pressure, if the data comparison is consistent, a proportional relief valve-variable loading oil pressure function (i.e. a working curve) is established, if the data comparison is inconsistent, the parameter initialization self-correction program is started again. After the second comparison of the current loading oil pressure, if the data comparison is inconsistent, the electromagnet is determined to be faulty and an alarm is given, and the electromagnet and other devices can be replaced.

[0122] The parameter initialization self-correction program is to give an instruction of the proportional relief valve, obtain the loading oil pressure under the corresponding instruction, and obtain the corresponding initialization working curve. When the electromagnet is faulty, the loading oil pressure does not correspond to the instruction of the proportional relief valve, and a reasonable curve cannot be formed, the current new device is determined to be faulty, and needs to be replaced. The proportional relief valve and the loading oil pressure are in a basic linear relationship, i.e. with the increase of the instruction of the proportional relief valve, the loading oil pressure is also gradually increased.

[0123] The proportional relief valve parameter self-correction control loop has the following characteristics: (1) the change in characteristics caused by the fault of the proportional electromagnetic valve during operation is overcome, the working curve is automatically corrected and the best value under the current operating condition is obtained, and the electromagnet fault is prompted to the operator; (2) the best proportional relief valve instruction is automatically selected according to the current operating parameter, the loading oil pressure is controlled to reach the current best working condition, and the economy and safety of the coal mill are improved.

[0124] Please refer to Figure 6 , Figure 6The flow chart of the proportional overflow valve parameter self-correction control method provided by the embodiment of the application has the following process: the mill outlet air pressure, the mill vibration, the mill current, the mill coal quantity, and the mill inlet air pressure are collected to establish a dynamic matrix optimization control model (i.e., an optimization matrix) in which the corresponding relationship between the mill outlet air pressure, the mill vibration, the mill current, the mill coal quantity, the mill inlet air pressure, and the variable loading oil pressure is stored. After the variable loading oil pressure instruction is generated, it is converted into a proportional overflow valve instruction, and then the movement of the electromagnet and the valve core is controlled to obtain the variable loading oil pressure, and the variable loading oil pressure is used to load the oil system. The variable loading oil pressure is compared with the initial proportional overflow valve parameter; if they are consistent, the proportional overflow valve parameter (i.e., the working curve) is unchanged; if they are inconsistent, the proportional overflow valve parameter self-correction is started, and the variable loading oil pressure corresponding to the current proportional overflow valve instruction is recorded to correct the initial working curve. The embodiment can also determine whether the variable loading oil pressure corresponding to different currents is consistent; if it is consistent, it is determined that the electromagnet or the valve core is faulty and an alarm information is displayed to prompt the maintenance; and the optimization control can be exited. To ensure that the mill does not malfunction due to abnormal variable loading oil pressure, the variable loading oil pressure instruction can be changed into the maximum value of the last 10 sampling periods.

[0125] The embodiment can collect historical data, and establish an optimization matrix of the variable loading oil pressure and the mill outlet air pressure, the mill vibration, the mill current, the mill coal quantity, and the mill inlet air pressure through dynamic matrix optimization control. The embodiment can also collect real-time mill production data, and obtain the optimal variable loading oil pressure instruction under the current working condition through dynamic optimization matrix. The variable loading oil instruction is obtained through the proportional overflow valve loading oil pressure function to obtain the proportional overflow valve instruction, and the proportional overflow valve instruction controls the in-situ electromagnet valve core to act to control the on-site variable loading oil pressure. The system samples the proportional overflow valve instruction and the variable loading oil pressure in real time, and compares them with the original proportional overflow valve function. If the current sampling data is consistent with the variable loading oil pressure corresponding to the same instruction in the last sampling period, the function is unchanged, and the execution state is maintained. For example, the current sampling data is the data at time T, the data of the last sampling period is the data at time T-1, and the data of the next sampling period is the data at time T+1. Each time corresponds to the variable loading oil pressure at the corresponding time.

[0126] If the current sampling data is inconsistent with the variable loading oil pressure corresponding to the same instruction in the last sampling period, the actual variable loading oil pressure corresponding to the current proportional overflow valve instruction is written into the proportional overflow valve working curve, the latest working curve corresponding to the current proportional overflow valve is obtained, and the system executes the operation according to the new working curve. When it is monitored that the variable loading oil pressure corresponding to 4 continuous current values of the proportional overflow valve remains unchanged and the trend changes differently, it is determined to be abnormal, the dynamic matrix optimization control module is exited, the variable loading oil pressure instruction is changed into the maximum value of the last 10 sampling periods, and the mill is prevented from being blocked.

[0127] For example, the original opening value at time T is A, and the oil pressure value is B; at time T+1, the opening value is A, but the actual oil pressure value is C; since the oil pressure value changes from B to C under the same opening A, it is considered that the electromagnetic valve characteristics or other problems cause the device characteristics to change, so the latest T+1 corresponding oil pressure C value is corresponded to A, and the oil pressure C data covers the oil pressure B, so as to complete the real-time updating of the working curve.

[0128] The embodiment provides a self-correction logic of a working curve of a proportional overflow valve of a coal mill, without manual correction of a hardware curve by using software, and the curve is modified by self-collecting running data. The embodiment combines energy-saving running indexes of the coal mill, collects key data such as a current of the coal mill and coal quality, adopts a dynamic optimization matrix model according to a pulverized coal system collection system, obtains a current working pressure of the proportional overflow valve, and achieves the purpose of economic operation. The electromagnetic valve fault alarm disposal loop provided by the embodiment compares the proportional overflow valve instruction and the variable load oil pressure corresponding relationship of the current sampling period and the previous sampling period, judges whether the current proportional overflow valve has a serious fault, that is, damage, jamming, pipe blockage, and changes the variable load oil pressure instruction in time, to ensure that the coal mill runs at the latest maximum oil pressure, and prevents the coal mill from being blocked due to loss of variable load. The computer control part in the embodiment is moved to DCS for completion, and other control devices can be externally connected, instead of using the design method of integral control + electromagnet, which is beneficial to online accident inspection and processing by operation personnel.

[0129] The proportional overflow valve control system of the coal mill provided in the embodiment can be applied to a distributed control system, the distributed control system is connected with the proportional overflow valve through a voltage controller, and the proportional overflow valve control system of the coal mill comprises:

[0130] An initialization module is configured to control the proportional overflow valve to perform parameter initialization and self-correction, and obtain a working curve; the working curve is used to describe the corresponding relationship between the proportional overflow valve instruction and the variable load oil pressure.

[0131] A target oil pressure determination module is configured to obtain current production data of the coal mill, and input the current production data into an optimization matrix to obtain a target variable load oil pressure; the optimization matrix is a matrix established by a dynamic matrix control algorithm, and the optimization matrix is used to describe the corresponding relationship between the production data and the variable load oil pressure.

[0132] An instruction determination module is configured to calculate a target proportional overflow valve instruction corresponding to the target variable load oil pressure by using the working curve.

[0133] A control module is configured to control the proportional overflow valve to perform corresponding actions according to the target proportional overflow valve instruction, and detect an actual variable load oil pressure of the coal mill.

[0134] The judgment module is configured to judge whether the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure conforms to the working curve, and is further configured to update the working curve according to the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure, so as to control the proportional relief valve by using the new working curve, if the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure does not conform to the working curve.

[0135] The embodiment is applied to a distributed control system connected with a proportional relief valve through a voltage controller, and the proportional relief valve instruction and the variable loading oil pressure are obtained by parameter initialization self-correction operation and are represented as a working curve. The current production data and an optimization matrix are used to predict a target variable loading oil pressure, and the proportional relief valve instruction corresponding to the target variable loading oil pressure is determined from the working curve. On the basis of the proportional relief valve instruction, the proportional relief valve is controlled according to the target proportional relief valve instruction, and the actual variable loading oil pressure is monitored. When the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure does not conform to the working curve, the working curve can be updated, so as to control the proportional relief valve by using the new working curve. The process of updating the working curve is implemented in the distributed control system, and the working curve can be dynamically adjusted to reflect the actual characteristics of the proportional relief valve as the operating conditions of the coal mill change. Therefore, the working curve of the proportional relief valve can be automatically corrected, and the control accuracy of the proportional relief valve is improved.

[0136] The initialization module controls the proportional relief valve to perform parameter initialization self-correction operation to obtain the working curve, and the process includes: constructing an instruction set; the instruction set contains multiple candidate proportional relief valve instructions, and the instruction parameter values corresponding to any two candidate proportional relief valve instructions are different; the candidate proportional relief valve instructions are selected from the instruction set in the order of low to high instruction parameter values, the proportional relief valve is controlled, and a first oil pressure set is recorded; the candidate proportional relief valve instructions are selected from the instruction set in the order of high to low instruction parameter values, the proportional relief valve is controlled, and a second oil pressure set is recorded; it is judged whether the variable loading oil pressures corresponding to the same candidate proportional relief valve instruction in the first oil pressure set and the second oil pressure set are the same; if yes, the working curve is established according to the corresponding relationship between the candidate proportional relief valve instruction and the variable loading oil pressure in the first oil pressure set. The instruction parameter value is a current value or a voltage value.

[0137] Further, the initialization module is further configured to, after judging whether the variable loading oil pressures corresponding to the same candidate proportional relief valve instruction in the first oil pressure set and the second oil pressure set are same, if the variable loading oil pressures corresponding to the same candidate proportional relief valve instruction in the first oil pressure set and the second oil pressure set are different, updating the cycle number, and judging whether the cycle number is greater than a preset value; if yes, determining that the proportional relief valve has a fault; and if no, entering the step of selecting the candidate proportional relief valve instruction from the instruction set in the order from low to high according to the instruction parameter value to control the proportional relief valve.

[0138] Further, the initialization module is further configured to, after judging whether the variable loading oil pressures corresponding to the same candidate proportional relief valve instruction in the first oil pressure set and the second oil pressure set are same, if the variable loading oil pressures corresponding to the same candidate proportional relief valve instruction in the first oil pressure set and the second oil pressure set are different, updating the cycle number, and judging whether the cycle number is greater than a preset value; if yes, determining that the proportional relief valve has a fault; and if no, entering the step of selecting the candidate proportional relief valve instruction from the instruction set in the order from low to high according to the instruction parameter value to control the proportional relief valve.

[0139] The matrix construction module is configured to obtain historical production data of the coal mill before inputting the current production data into an optimization matrix to obtain a target variable loading oil pressure, wherein the historical production data comprises any one or a combination of several of the following: a coal mill current, a coal mill coal quantity, a coal mill inlet air pressure, a coal mill outlet air pressure and a coal mill vibration data; and the matrix construction module is further configured to train a prediction model using a corresponding relationship between the historical production data and historical variable loading oil pressure, and to construct the optimization matrix corresponding to the prediction model by a dynamic matrix control algorithm.

[0140] Further, the matrix construction module obtains the historical production data of the coal mill by: obtaining the historical production data of the coal mill under multiple working conditions from a device log.

[0141] Correspondingly, the matrix construction module further comprises:

[0142] The oil pressure reading module is configured to obtain the historical variable loading oil pressure corresponding to each historical production data from the device log before training the prediction model using the corresponding relationship between the historical production data and the historical variable loading oil pressure.

[0143] Further, the matrix construction module further comprises:

[0144] The fault detection module is configured to obtain a variation trend of instruction parameter values corresponding to proportional relief valve instructions issued in the last n times, to obtain a variation trend of oil pressures corresponding to actual variable loading oil pressures detected in the last n times, to judge whether the variation trend of the instruction parameter values is consistent with the variation trend of the oil pressures, and to determine that the proportional relief valve has a fault if the variation trend of the instruction parameter values is not consistent with the variation trend of the oil pressures. The instruction parameter value is a current value or a voltage value.

[0145] Further, the matrix construction module further comprises:

[0146] The fault processing module is configured to obtain a reference proportional overflow valve instruction after determining that the proportional overflow valve has a fault, wherein the reference proportional overflow valve instruction is a proportional overflow valve instruction with the largest instruction parameter value among the last m proportional overflow valve instructions; and the fault processing module is further configured to control the proportional overflow valve to perform a corresponding action according to the reference proportional overflow valve instruction.

[0147] Since the embodiments of the system part correspond to the embodiments of the method part, the embodiments of the system part are described in the description of the embodiments of the method part, and are not described here.

[0148] The application further provides a storage medium having a computer program stored thereon, and the computer program can implement the steps provided by the above embodiments when executed. The storage medium can include a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0149] The application further provides an electronic device, which can include a memory and a processor, the memory has a computer program stored therein, and the processor can implement the steps provided by the above embodiments when calling the computer program in the memory. Of course, the electronic device can also include various network interfaces, power supplies and other components.

[0150] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the device disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part. It should be pointed out that, for ordinary skilled in the art, without departing from the principles of the application, the application can be improved and modified, and these improvements and modifications also fall within the protection scope of the application.

[0151] It is further noted that the terminology "first", "second" and the like used in the specification are merely used for differentiating one entity or action from another, and do not necessarily imply any actual physical or logical relationship or order between such entities or actions. Moreover, the use of the term "including", "containing" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or apparatus that comprises a list of elements is not required to comprise only those elements but can include other elements not expressly listed or inherent to such process, method, article or apparatus. An element preceded by "comprises a..." does not, without further restriction, preclude the existence of additional elements of the same nature as those recited.

Claims

1. A proportional relief valve control method for a coal mill, characterized by, The application is applied to a distributed control system with a working curve setting function, the distributed control system is connected with a proportional relief valve through a voltage controller, and the proportional relief valve control method of the coal mill comprises the following steps: Control the proportional relief valve to perform parameter initialization self-correction operation to obtain a working curve; wherein the working curve is used to describe the corresponding relationship between the proportional relief valve instruction and the variable loading oil pressure; Obtain the current production data of the coal mill, and input the current production data into an optimization matrix to obtain a target variable loading oil pressure; wherein the optimization matrix is a matrix established by a dynamic matrix control algorithm, and the optimization matrix is used to describe the corresponding relationship between the production data and the variable loading oil pressure; Calculate the target proportional relief valve instruction corresponding to the target variable loading oil pressure through the working curve; Control the proportional relief valve to execute corresponding actions according to the target proportional relief valve instruction, and detect the actual variable loading oil pressure of the coal mill; Determine whether the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure conforms to the working curve; If not, update the working curve according to the corresponding relationship between the target proportional relief valve instruction and the actual variable loading oil pressure, so as to control the proportional relief valve by using the new working curve; Wherein, the control of the proportional relief valve to perform parameter initialization self-correction operation to obtain a working curve comprises the following steps: Construct an instruction set; wherein, there are multiple alternative proportional relief valve instructions in the instruction set, and the instruction parameter values corresponding to any two alternative proportional relief valve instructions are different; the instruction parameter value is a current value or a voltage value; Select an alternative proportional relief valve instruction from the instruction set according to the order from low to high of the instruction parameter value to control the proportional relief valve, and record the variable loading oil pressure to obtain a first oil pressure set; Select an alternative proportional relief valve instruction from the instruction set according to the order from high to low of the instruction parameter value to control the proportional relief valve, and record the variable loading oil pressure to obtain a second oil pressure set; Determine whether the variable loading oil pressures corresponding to the same alternative proportional relief valve instruction in the first oil pressure set and the second oil pressure set are the same; If yes, establish the working curve according to the corresponding relationship between the alternative proportional relief valve instruction and the variable loading oil pressure in the first oil pressure set.

2. The method of claim 1, wherein the proportional relief valve control method of the coal mill is characterized by, After determining whether the variable loading oil pressures corresponding to the same alternative proportional relief valve instruction in the first oil pressure set and the second oil pressure set are the same, the following steps are further included: If the variable loading oil pressures corresponding to the same alternative proportional relief valve instruction in the first oil pressure set and the second oil pressure set are not the same, update the cycle number and determine whether the cycle number is greater than a preset value; If yes, it is determined that the proportional relief valve has a fault; If not, enter the step of selecting an alternative proportional relief valve instruction from the instruction set according to the order from low to high of the instruction parameter value to control the proportional relief valve.

3. The method of claim 1, wherein the proportional relief valve control method of the coal mill is characterized by, Before inputting the current production data into the optimization matrix to obtain the target variable loading oil pressure, the following steps are further included: Obtaining historical production data of the coal mill; wherein the historical production data comprises any one or a combination of mill current, mill coal quantity, mill inlet air pressure, mill outlet air pressure and mill vibration data; Training a prediction model using the historical production data and the corresponding relationship between the historical variable load oil pressure, and constructing the optimization matrix corresponding to the prediction model through a dynamic matrix control algorithm.

4. The method of claim 3, wherein the proportional relief valve control method of the coal mill is characterized by, Obtaining historical production data of the coal mill, comprising: Obtaining the historical production data of the coal mill under various working conditions from the device log; Correspondingly, before training the prediction model using the historical production data and the corresponding relationship between the historical variable load oil pressure, it further comprises: Obtaining the historical variable load oil pressure corresponding to each historical production data from the device log.

5. The method of claim 1, wherein the proportional relief valve control method of the coal mill is characterized by, Further comprising: Obtaining the instruction parameter value change trend corresponding to the proportional overflow valve instruction issued in the last n times; Obtaining the oil pressure change trend corresponding to the actual variable load oil pressure detected in the last n times; Judging whether the instruction parameter value change trend is consistent with the oil pressure change trend; If not, it is determined that the proportional overflow valve has a fault.

6. The proportional overflow valve control method for a coal mill according to claim 5, characterized in that, After determining that the proportional overflow valve has a fault, it further comprises: Obtaining a reference proportional overflow valve instruction; wherein the reference proportional overflow valve instruction is the proportional overflow valve instruction with the largest instruction parameter value among the proportional overflow valve instructions issued in the last m times; Controlling the proportional overflow valve to perform corresponding actions according to the reference proportional overflow valve instruction.

7. A proportioning overflow valve control system for a coal mill, characterized by, Applied to a distributed control system with a working curve setting function, the distributed control system is connected with a proportional overflow valve through a voltage controller, and the proportional overflow valve control system of the coal mill comprises: An initialization module for controlling the proportional overflow valve to perform parameter initialization self-correction operation to obtain a working curve; wherein the working curve is used to describe the corresponding relationship between the proportional overflow valve instruction and the variable load oil pressure; A target oil pressure determination module for obtaining current production data of the coal mill and inputting the current production data into an optimization matrix to obtain a target variable load oil pressure; wherein the optimization matrix is a matrix established through a dynamic matrix control algorithm, and the optimization matrix is used to describe the corresponding relationship between the production data and the variable load oil pressure; An instruction determination module for calculating a target proportional overflow valve instruction corresponding to the target variable load oil pressure through the working curve; A control module for controlling the proportional overflow valve to perform corresponding actions according to the target proportional overflow valve instruction, and detecting the actual variable load oil pressure of the coal mill; A judgment module for judging whether the corresponding relationship between the target proportional overflow valve instruction and the actual variable load oil pressure conforms to the working curve; and further for updating the working curve according to the corresponding relationship between the target proportional overflow valve instruction and the actual variable load oil pressure if the corresponding relationship does not conform to the working curve, so as to control the proportional overflow valve using the new working curve; The process in which the initialization module controls the proportional overflow valve to perform parameter initialization self-correction operation to obtain the working curve comprises: Constructing an instruction set, wherein the instruction set has multiple alternative proportional relief valve instructions, and any two alternative proportional relief valve instructions have different instruction parameter values; the instruction parameter value is a current value or a voltage value; Selecting an alternative proportional relief valve instruction from the instruction set according to the instruction parameter value from low to high to control the proportional relief valve, and recording the variable load oil pressure to obtain a first oil pressure set; Selecting an alternative proportional relief valve instruction from the instruction set according to the instruction parameter value from high to low to control the proportional relief valve, and recording the variable load oil pressure to obtain a second oil pressure set; Judging whether the variable load oil pressure corresponding to the same alternative proportional relief valve instruction in the first oil pressure set and the second oil pressure set is the same; If yes, establishing the working curve according to the corresponding relationship between the alternative proportional relief valve instruction and the variable load oil pressure in the first oil pressure set.

8. An electronic device, comprising: The memory stores a computer program, and the processor calls the computer program in the memory to realize the steps of the proportional relief valve control method of the coal mill according to any one of claims 1 to 6.

9. A storage medium, characterized by The storage medium stores computer executable instructions, and the computer executable instructions are loaded and executed by the processor to realize the steps of the proportional relief valve control method of the coal mill according to any one of claims 1 to 6.

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