A new type of dry process cement raw material vertical mill real-time optimization method and system

Abstract

The application discloses a novel dry-process cement raw material vertical mill real-time optimization method and system, and belongs to the technical field of industrial control. The method comprises the following steps: S1, collecting raw material vertical mill operation parameters in real time, including the mill inlet table output, the inlet and outlet pressure difference, the mill main motor current, the circulating fan current, the mill vibration value and the outlet temperature; S2, performing filtering processing on the collected data; S3, performing closed-loop control through an expert control system; S4, evaluating the mill state once every 10 minutes through an expert optimization system, and dynamically adjusting the negative pressure set value based on a knowledge base rule; and S5, repeatedly performing steps S3-S4 to realize continuous optimization of the output. Through the collaborative architecture of the expert control system and the expert optimization system, the fine control logic and the intelligent knowledge base design, the application realizes efficient regulation and control of the raw material mill production process. Under the premise of ensuring the safety of equipment, the application can dynamically iterate the negative pressure set value to improve the mill capacity to the optimal interval, and significantly improve the production economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial control, more particularly to a real-time optimization method and system for raw meal vertical mill of new dry cement. BACKGROUND

[0002] Cement is one of the important raw materials for national economic construction, and can be widely used in civil, industrial, agricultural, water conservancy, transportation and military engineering. In the production of new dry cement, raw meal grinding is the core link between raw material preparation and clinker burning. Its core role is to physically and chemically homogenize and finely control the particle size of the raw meal. It grinds the pre-homogenized raw meal to a specified fineness (usually 80 μm residue ≤ 12-14%, specific surface area ≥ 300-350 m² / kg), significantly increases the specific surface area of the material, and realizes high uniformity of chemical composition on a microscopic scale.

[0003] Ensuring the continuous and stable operation of the raw meal grinding link is of great overall importance: first, it is the core guarantee of high-quality clinker, and the stability of grinding fineness, uniformity and composition directly determines the clinker burning efficiency, mineral composition uniformity and final strength. Secondly, it is the basis for stable operation of the kiln system, and stable raw meal input is a prerequisite for precise control of kiln operating parameters and avoidance of thermal disorder. Thirdly, it deeply affects the system energy consumption, and stable and efficient operation of the grinding system itself (such as vertical mill / roller press) directly reduces the power consumption, while stable raw meal quality (fineness, moisture) significantly reduces the additional heat consumption caused by difficulty in burning or decrease in preheating efficiency. Finally, it is the link of continuous and efficient operation of the production line, and any interruption or quality fluctuation in grinding will force the subsequent process to reduce production or even stop the kiln, which will seriously damage the operation rate and capacity. Therefore, the stability of raw meal grinding is not only the physical and chemical basis for high-quality clinker production, but also the key factor for realizing high yield, low consumption and long-period safe operation of the whole production line and the economic benefit guarantee point.

[0004] Under the condition of the prior art, the control of the raw meal vertical mill of new dry cement is mainly manual adjustment by the operator, which has high labor intensity, and due to the strong coupling and large time delay of the mill adjustment, the manual control of the mill has poor stability, and cannot ensure that the mill is always in the optimal operating condition. In view of this, we propose a real-time optimization method and system for raw meal vertical mill of new dry cement. SUMMARY

[0005] The present application relates to the technical field of industrial control, more particularly to a real-time optimization method and system for raw meal vertical mill of new dry cement.

[0006] To achieve the above object, the present application provides the following technical scheme:

[0007] A new type of dry cement raw material vertical mill real-time optimization method and system, comprising the following steps:

[0008] S1, real-time acquisition of raw material vertical mill operation parameters, including the output of the mill, the pressure difference between the inlet and outlet, the main motor current of the mill, the circulating fan current, the mill vibration value and the outlet temperature;

[0009] S2, filtering the collected data, the filtering formula is:

[0010] ;

[0011] Where OUT n is the n period output value, OUT n-1 is the output value of the n-1 period, IN n is the n period input value, and tz is the system calculation period. T1 is the filtering time;

[0012] S3, execute closed-loop control through expert control system:

[0013] Taking the pressure difference between the inlet and outlet as the controlled variable and the output of the mill as the operating variable, the incremental PID algorithm is used to calculate the basis value of the output of the mill;

[0014] According to the circulating fan current, the output of the mill is dynamically corrected: every 1A increase in current increases 0.5 tons, and every 1A decrease in current reduces 0.5 tons;

[0015] When the pressure difference is in the stable interval, the adjustment range of the output of the mill is halved;

[0016] S4, evaluate the mill state every 10 minutes through the expert optimization system, and dynamically adjust the negative pressure set value based on the knowledge base rules:

[0017] If the outlet temperature, vibration and current are normal, the negative pressure set value is increased by 5Pa;

[0018] If the main motor current is out of limit or the vibration is out of limit, the negative pressure set value is reduced by 30Pa and the feeding amount is reduced by 4 tons;

[0019] S5, repeat steps S3-S4 to realize continuous optimization of output.

[0020] Preferably, step S3 further comprises safety protection logic:

[0021] When the instantaneous value of the main motor current is >130A, the feeding amount is immediately reduced by 4 tons;

[0022] When the main motor current is >126A for 5 consecutive control periods, the feeding amount is reduced by 4 tons;

[0023] The above operation is only allowed to trigger once in 480 seconds.

[0024] Preferably, the knowledge base rules in step S4 include:

[0025] If the average of the mill outlet temperature is lower than the lower limit, the negative pressure is prohibited from being raised;

[0026] If the circulating fan current is <80A, it is marked as an abnormality in the mill and the negative pressure is prohibited from being raised;

[0027] If the vibration value is accumulated for 10 minutes and is greater than or equal to 5 times the upper limit of 90%, it is marked as a vibration abnormality.

[0028] Preferably, the bench time yield adjustment in step S3 is associated with the trend of the stockyard elevator current:

[0029] The trend of the stockyard elevator current is collected in each control cycle and is included in the bench time yield calculation model in a weighted manner.

[0030] A new type of real-time optimization system for raw material vertical mills of dry process cement, comprising:

[0031] A data acquisition module: real-time acquisition of mill operation parameters through the OPC interface of the DCS system;

[0032] A filtering module: filtering methods are used to clean the collected key parameters, and the filtering methods meet:

[0033] ;

[0034] Where OUT n is the output value of the nth n cycle, OUT n-1 is the output value of the n-1th cycle, IN n is the input value of the nth cycle, and tz is the system calculation cycle, and T1 is the filtering time;

[0035] An expert control module: PID algorithm, circulating fan current linkage correction, and differential pressure interval adjustment rules are built-in;

[0036] An expert optimization module: a knowledge base and an inference machine, the knowledge base stores temperature, current, and vibration threshold rules, and the inference machine outputs negative pressure setting value adjustment instructions in a 10-minute cycle;

[0037] A safety protection module: executes main motor current overrun protection and vibration overrun linkage control.

[0038] Preferably, the expert control module supports a manual intervention mechanism:

[0039] When the operator manually modifies the bench time yield, the system synchronously sets the value and maintains it for 5 minutes, and then automatically restores the closed-loop control.

[0040] Preferably, the expert optimization module comprises a negative pressure adjustment locking function:

[0041] After performing the negative pressure reduction operation, enter a 10-minute locking period to suspend other increase adjustment.

[0042] Compared with the prior art, the present application has the beneficial effects that:

[0043] The present application realizes efficient regulation and control of the raw mill production process through the collaborative architecture of the expert control system and the expert optimization system, refined control logic, and intelligent knowledge base design. The core advantages are as follows:

[0044] 1. Dynamic collaborative optimization mechanism to achieve accurate balance between yield and energy consumption

[0045] Adopting a cyclic collaborative mode of "steady-state regulation-optimization reasoning-parameter iteration", the expert control system ensures basic steady-state operation, and the expert optimization system continuously taps into production capacity potential. Compared with traditional single control systems, the present application can increase mill production capacity to the optimal range through dynamic iteration of the negative pressure set value while ensuring equipment safety, and can actually verify that it can increase production by 2% while reducing unit energy consumption by 1.5%, significantly improving production economy.

[0046] 2. Multi-level safety protection system to improve equipment operation reliability

[0047] A three-level safety protection logic of "real-time overrun protection+trend early warning intervention+regulation limiting mechanism" is constructed: the double threshold value trigger protection of the main motor current (instantaneous 130A / continuous 5 cycles 126A) can quickly avoid the risk of equipment overload; the vibration trend early warning (frequent approach to the upper limit mark abnormality) effectively prevents the vicious cycle of "wear-vibration intensification"; the 480-second protection logic single trigger limit avoids system fluctuations caused by excessive regulation. The above mechanism reduces the unplanned downtime of the equipment by more than 60%, significantly prolonging the service life of core components such as mill rollers, mill disc liners, etc. (the extension period can reach 30%).

[0048] 3. Self-adaptive regulation strategy to enhance system anti-interference ability

[0049] Through multiple dynamic correction logics, stable operation under complex working conditions is realized: real-time linkage correction of circulating fan current and hourly yield (±1A corresponds to ±0.5 tons of adjustment), which can quickly respond to the influence of air volume change on the grinding efficiency; the regulation amplitude reduction rule (amplitude reduction by half) within the pressure difference interval reduces the steady-state fluctuation;

[0050] Weighted associated regulation of the stock elevator current trend realizes the coordinated response of the upstream and downstream equipment states. Under the interference conditions of raw material composition fluctuation, environmental temperature change, etc., the system can still maintain the hourly yield standard deviation within ±1.5 tons, with a stability improvement of more than 30% compared with traditional PID control.

[0051] 4. Intelligent knowledge base and reasoning machine, reduce the dependence on artificial

[0052] Expert knowledge base covers multi-dimensional rules of core parameters such as temperature, current, vibration (10-minute average / trend / instantaneous value comprehensive judgment), and the reasoning machine realizes self-adaptive iteration of negative pressure set value through periodic evaluation. Cooperate with the "manual intervention 5-minute maintenance + automatic recovery" mechanism, not only retain the operator's emergency control right, but also reduce more than 80% of the frequency of manual adjustment through system automatic optimization, reduce the dependence on experienced operators' experience, and avoid subjective bias of human operation.

[0053] 5. Modular architecture design, strong scalability and compatibility

[0054] The core parameters such as cycle setting, protection threshold and adjustment coefficient of the control system support modular configuration, which can be flexibly adjusted according to different types of mills or raw material characteristics (limestone, clay ratio difference). The system does not need to modify the main equipment of the mill, and can realize deployment only by upgrading the control system, with short modification period, suitable for technical upgrading of various raw mill production lines. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 The method flowchart for collecting and calculating the pressure difference of the raw material vertical mill and calculating the table time result according to the pressure difference calculation result of the present application;

[0056] Figure 2 The internal logic flowchart for calculating the pressure difference by the pressure difference calculator;

[0057] Figure 3 The actual use case diagram of the present application;

[0058] Figure 4 The running situation after the raw mill optimization system is put into operation Figure 1 ;

[0059] Figure 5 The running situation after the raw mill optimization system is put into operation Figure 2 .

[0060] Explanation of the reference numerals in the figure: 1, raw mill; 2, rotary feeder; 3, three-way valve; 4, metal detector; 5, iron separator; 6, belt conveyor I; 7, elevator; 8, waste pool; 9, belt conveyor II. DETAILED DESCRIPTION

[0061] 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 part of the embodiments of the present application, not all the embodiments.

[0062] Embodiment:

[0063] Please refer to Figures 1-5 A new type of dry process cement raw material vertical mill real-time optimization method and system, comprising the following steps:

[0064] S1, real-time acquisition of raw material vertical mill operation parameters, including the yield of the mill, the pressure difference between the inlet and outlet, the current of the main motor of the mill, the current of the circulating fan, the vibration value of the mill and the outlet temperature; Through real-time acquisition of the core parameters such as the yield of the mill, the pressure difference between the inlet and outlet, the comprehensive perception of the running state of the mill is realized, the problem of not timely parameter acquisition and missing key indicators in traditional manual monitoring is solved, and complete data basis is provided for subsequent control and optimization, so that the accuracy of the system to judge the working condition of the mill is improved.

[0065] S2, adopt filtering method to clean the collected key parameters, the filtering method meets:

[0066] ;

[0067] Where OUT n is the output value of the first n period, OUT n-1 is the output value of the n-1 period, IN n is the input value of the n period, tz is the system calculation period, and T1 is the filtering time.

[0068] The process data of the yield of the mill, the pressure difference between the inlet and outlet, the current of the main motor of the mill and other variables are collected and cleaned. Real-time acquisition of process data is realized through DCS system OPC interface. The collected data is processed by the above filtering method to weaken the noise influence in the data.

[0069] S3, execute closed-loop control through expert control system:

[0070] Taking the pressure difference between the inlet and outlet as the controlled variable and the yield of the mill as the operating variable, an incremental PID algorithm is used to calculate the yield of the mill.

[0071] According to the current of the circulating fan, the yield of the mill is dynamically corrected: the current increases by 0.5 tons per 1A increase, and decreases by 0.5 tons per 1A decrease; The circulating fan current linkage correction rule solves the influence of fan working condition change (such as impeller wear and wind fluctuation) on the yield of the mill, so that the stability of the yield of the mill under the same fan current is improved.

[0072] When the pressure difference is in the stable interval, the adjustment range of the yield of the mill is halved; The pressure difference interval adjustment reduction mechanism avoids excessive adjustment of the mill in the stable state, and reduces the fatigue loss of the equipment.

[0073] The present application aims at the poor manual control stability of raw material vertical mill, and realizes stable control of key parameters of the raw material vertical mill through PID algorithm and expert library logic. For example, the mill pressure difference is controlled through automatic adjustment of the mill table time, and the basic given value of the mill table time is calculated by using the incremental PID algorithm. On this basis, the present application sets current protection values A and A1, and sets a history current array arr of the last 5 control periods. When the average value of the array arr is greater than the current A or the last array in the array arr is greater than A1, the table time is reduced by 5 tons at one time, so as to protect the mill from jumping and stopping due to too high current.

[0074] S4, the mill state is evaluated every 10 minutes through the expert optimization system, and the negative pressure set value is dynamically adjusted based on the knowledge base rules:

[0075] If the outlet temperature, vibration and current are normal, the negative pressure set value is increased by 5 Pa;

[0076] If the main motor current is out of limit or the vibration is out of limit, the negative pressure set value is reduced by 30 Pa and the feeding amount is reduced by 4 tons;

[0077] The periodic evaluation every 10 minutes and the dynamic adjustment of the negative pressure realize continuous optimization of the mill working condition, and the table time yield is improved on the premise of ensuring that the product fineness meets the standard. The differential adjustment of the negative pressure set value (normal + 5 Pa, out of limit - 30 Pa) not only gradually improves the negative pressure to tap the production potential, but also quickly reduces the pressure to protect the equipment in case of abnormality, so that the unplanned downtime of the mill is reduced. The knowledge base rules (such as the lower limit of temperature to prohibit upward adjustment) avoid process disorder caused by blind optimization (such as material adhesion to the grinding disc caused by too low temperature), and ensure the safety of the optimization process.

[0078] S5, the steps S3-S4 are repeated to realize continuous optimization of the yield.

[0079] In the present application, the step S3 further includes safety protection logic:

[0080] When the instantaneous value of the main motor current is greater than 130 A, the feeding amount is immediately reduced by 4 tons;

[0081] When the main motor current is greater than 126 A for 5 consecutive control periods, the feeding amount is reduced by 4 tons;

[0082] The above operation is only allowed to trigger once in 480 seconds.

[0083] The double protection mechanism of the main motor current out of limit (instantaneous value > 130 A or 5 consecutive periods > 126 A) can trigger the feeding amount reduction operation within 15 seconds, so as to avoid motor overload and burnout; the single trigger limitation within 480 seconds prevents working condition shock caused by frequent adjustment, so that the number of motor failure shutdowns is reduced.

[0084] In the present application, the knowledge base rules in step S4 include:

[0085] If the average outlet temperature of the mill is lower than the lower limit, the negative pressure is prohibited from being raised;

[0086] If the circulating fan current is <80A, it is marked as an abnormality in the mill and the negative pressure is prohibited from being raised;

[0087] If the vibration value is accumulated for 10 minutes and reaches the upper limit of 90% for 5 times, it is marked as a vibration abnormality.

[0088] In the present application, the bench time yield adjustment in step S3 is associated with the current trend of the stockyard elevator:

[0089] The current trend of the stockyard elevator is collected in each control cycle and is included in the bench time yield calculation model in a weighted manner.

[0090] The current trend of the elevator is included (such as a sustained increase in current indicating an increase in load of the subsequent conveying system), the bench time yield is adjusted in advance, the contradiction of "high yield of the mill but insufficient conveying capacity of the subsequent system" is avoided, the blockage rate of the raw material stockyard system is reduced, and the continuous operation of the entire production line is ensured.

[0091] The present application combines the production practice and excellent experience of new dry cement to determine that the key parameters of the raw material vertical mill that need to be automatically controlled are the bench time yield entering the mill, the pressure difference between the inlet and outlet of the raw material vertical mill, and the main motor current of the mill. The bench time entering the vertical mill is used as the operating variable, the pressure difference between the inlet and outlet is used as the controlled variable, and the main motor current of the mill is used as the auxiliary variable. The above operating variable and controlled variable are the key variables affecting the production stability and energy consumption of the vertical mill. Balanced control of the bench time and the pressure difference can achieve the goal of stable production and energy saving and consumption reduction of the mill. The main motor current of the mill is an auxiliary variable for judging the running condition of the mill and safety protection, and has an auxiliary effect on preventing the mill from stopping.

[0092] A new dry cement raw material vertical mill real-time optimization system is applied to the above method and comprises:

[0093] A data acquisition module: the running parameters of the mill are obtained in real time through the OPC interface of the DCS system;

[0094] A filtering module: data preprocessing is performed on the filtering formula in claim 1; the filtering formula is:

[0095] ;

[0096] Wherein OUT n is the output value of the nth cycle, OUT n-1 is the output value of the (n-1)th cycle, IN n is the input value of the nth cycle, tz is the system calculation period, and T1 is the filtering time;

[0097] Expert control module: Built-in PID algorithm, circulating fan current linkage correction and differential pressure range adjustment rules; Among them, the expert control module supports a manual intervention mechanism: when the operator manually modifies the hourly output, the system synchronizes the set value and holds it for 5 minutes, after which it automatically resumes closed-loop control.

[0098] Expert Optimization Module: Includes a knowledge base and an inference engine. The knowledge base stores rules for temperature, current, and vibration thresholds. The inference engine outputs negative pressure setpoint adjustment commands in 10-minute cycles. The expert optimization module includes a negative pressure adjustment lock function: after performing a negative pressure reduction operation, it enters a 10-minute lock cycle to suspend other increases in adjustment.

[0099] Safety protection module: Implements over-limit protection for main motor current and over-limit vibration linkage control.

[0100] Figure 3 This is a practical application example of the invention. The invention has been practically applied on the 2500t / d production line of Hanzhong Xixiang Yaobai Cement Co., Ltd. The optimization effects achieved by the invention are as follows: Figures 4-5 To optimize the operation of the raw material mill system after it is put into operation.

[0101] Depend on Figure 4 As can be seen, the green line represents the outlet negative pressure setpoint. The grinding condition is assessed every 15 minutes. When all mill parameters meet the setpoint, the setpoint is reduced by 5 Pa. If the setpoint decreases by 105 Pa within 6 hours, the grinding condition is identified as near-saturation, and settingpoint modification is stopped. Figure 4 The purple line represents the output. Analysis shows that as the outlet negative pressure decreases, the mill's hourly rate also increases with the set value, gradually rising from 259 t / h to 262.8 t / h, with the average hourly rate increasing by 3.8 t / h.

[0102] Depend on Figure 5 The negative pressure setting at the outlet indicates that if the mill current is too high or the vibration is too large, the setting will increase by 5 Pa. When the mill returns to normal in the next cycle, the setting will decrease by 5 Pa, dynamically adjusting the setting.

[0103] Through data analysis, the optimization system will dynamically adjust in real time according to the grinding conditions. It can lower the set value during normal operation and increase the set value when the grinding is full or unstable. Operators, central control directors, and process engineers can modify the mill judgment parameters at any time according to the needs of the site, thereby realizing dynamic optimization control of the raw material mill.

[0104] I. Collaborative Operation Mechanism of Expert Control System and Expert Optimization System

[0105] The application adopts the operation mode of combining the expert control system with the expert optimization system, and the specific process is as follows: first, the running state of the mill is regulated and controlled to a steady state by the expert control system, so that the mill pressure difference reaches the initial set value of the operator. At this time, the mill meets the basic running target, but the best yield is not realized. Then the expert optimization system is started, which transmits the current mill state parameters into the expert system knowledge base, and through the analysis of the rule base in the knowledge base and the logical operation of the inference machine, the optimized pressure difference set value is output. After the set value is fed back to the expert control system, the control system gradually regulates and controls the mill to a new steady state. The above-mentioned process of "steady state regulation-optimization reasoning-parameter updating-new steady state establishment" is alternately circulated until the mill reaches the maximum best yield, and finally the technical effect of increasing yield and reducing consumption is realized.

[0106] II. Expert control system design

[0107] 1. Control cycle parameter setting

[0108] The automatic regulation of the raw mill hourly output adopts a PID closed-loop control mode with a control cycle of 15 seconds. After the operator sets the pressure difference target value, the system stabilizes the mill pressure difference at the set target value by dynamically adjusting the output.

[0109] 2. Manual intervention and automatic recovery mechanism

[0110] When the operator manually modifies the hourly output on the raw mill operation interface, the system detects the operation in real time and synchronizes the hourly set value of the expert control system with the manual set value of the operator in real time. This manual setting state lasts for 5 minutes, and after 5 minutes, the system automatically switches back to the automatic regulation mode of the expert control system.

[0111] 3. Cumulative adjustment amount limitation mechanism

[0112] During the expert system control, if the cumulative adjustment amount of the hourly output exceeds 2 tons, the system automatically stops the output adjustment operation for 1 minute, and then resumes the adjustment function after 1 minute.

[0113] 4. Dynamic correction strategy of circulating fan current to hourly output

[0114] The system monitors the circulating fan current of the raw mill in real time: if the current increases by 1A, the hourly output calculated by the expert control system is increased by 0.5 tons; if the current decreases by 1A, the hourly output calculated by the expert control system is decreased by 0.5 tons, to realize the dynamic correction of the hourly output.

[0115] 5. Adjustment effect reduction rule in the pressure difference interval

[0116] When the raw mill pressure difference is within the set stable interval range, the adjustment range of the hourly output is automatically halved to reduce the influence of adjustment fluctuations on system stability.

[0117] 6. Main motor current over-limit protection and feed rate adjustment logic

[0118] If the instantaneous value of the raw mill main motor current exceeds 130 A, the system immediately reduces the feed rate by 4 tons; if the main motor current exceeds 126 A for 5 consecutive control periods (cumulative duration of 75 seconds), the system also performs the operation of reducing the feed rate by 4 tons. The above two trigger conditions are only allowed to be executed once within any consecutive 480 seconds to avoid excessive regulation.

[0119] 7. Association adjustment mechanism of table hour output and stock elevator current trend

[0120] The system collects the change trend (non-instantaneous value) of the stock elevator current in each control period and incorporates the trend into the calculation model of the table hour output adjustment in a weighted manner to realize dynamic association optimization of the table hour output and the change trend of the stock elevator current.

[0121] III. Construction of expert knowledge base

[0122] 1. Mill outlet temperature rule

[0123] When the mill outlet temperature is too low, it is easy to cause insufficient drying of the material, high moisture content, and thus increase the grinding resistance and reduce the table hour output. When the temperature is lower than the set lower limit value, it indicates that there is too much material in the mill or the mill outlet condition is poor, at which time the system prohibits negative pressure up-regulation to avoid mill overload saturation.

[0124] Rule definition: IF mill outlet temperature average < raw mill outlet temperature lower limit value THEN mark as low mill temperature

[0125] When the mill outlet temperature is too high, the material is prone to premature dehydration to form an "over-drying" phenomenon, which increases the grinding resistance and reduces the table hour output. When the 10-minute average temperature exceeds the set upper limit value, the system prohibits negative pressure up-regulation to prevent the condition from deteriorating.

[0126] Rule definition: IF mill outlet temperature 10-minute average > raw mill outlet temperature upper limit value THEN mark as high mill temperature

[0127] 2. Mill current rule

[0128] When the main motor current of the mill is too high, abnormal friction between the mill roller skin and the mill disc liner will accelerate wear and tear, reducing the grinding efficiency. The system monitors the current in real time, and when the instantaneous current exceeds the safe upper limit, it is determined that the current is over-limit.

[0129] Rule definition: IF mill main motor current instantaneous value > current safe upper limit THEN mark as mill current over-limit

[0130] If the current is close to the safe upper limit for a long time (not reaching the operating limit), the increase in production caused by the upward adjustment of the negative pressure will destroy the stability of the mill. When the cumulative number of times within the period exceeds 3 or more times close to the safe upper limit (95% of the safe upper limit), the system prohibits the upward adjustment of the negative pressure.

[0131] Rule definition 2: IF the cumulative number of times within the period exceeds 3 or more times close to the safe upper limit THEN mark as mill current imminent over-limit abnormality.

[0132] 3. Mill vibration rules

[0133] When the mill encounters large pieces of material or saturated material, it will produce abnormal vibration, causing the mill roller to frequently come into rigid contact with the mill disc liner, accelerating the peeling of the surface hardening layer, forming a vicious cycle of "wear → vibration intensification → re-wear"; severe vibration may trigger a protective trip, and restarting requires idle running for more than 30 minutes, resulting in a single downtime loss of more than 100 tons of production capacity. Therefore, the vibration amplitude needs to be strictly controlled.

[0134] When the maximum vibration value within 10 minutes exceeds the safe vibration threshold, it is determined that the vibration is over-limit.

[0135] Rule definition: IF the maximum vibration value of the mill within 10 minutes > safe vibration threshold THEN mark as mill vibration over-limit

[0136] When the mill is unstable (vibration frequently close to the upper limit), the cumulative number of times within 10 minutes close to the vibration upper limit (90% of the vibration upper limit) exceeds 5, it is marked as vibration abnormality.

[0137] Rule definition: IF the cumulative number of vibration values of the mill within 10 minutes ≥ 5 times close to the vibration upper limit THEN mark as mill vibration abnormality

[0138] 4. Mill circulating fan rules

[0139] When the circulating fan current is low, it reflects that the system air volume is insufficient, and the ground material cannot be effectively taken into the classifier, causing the accumulation of fine powder on the mill disc, resulting in a decrease in suspension conveying capacity, an increase in mill internal pressure difference, a decrease in grinding efficiency, and in severe cases, the classifier will slow down due to insufficient feed, and the product fineness will be out of control. When the fan current is lower than the set lower limit value, it is determined that the mill discharge condition is abnormal.

[0140] Rule definition: IF the circulating fan current of the mill < set circulating fan current lower limit value (80A) THEN mark as mill discharge abnormality

[0141] Four, reasoning machine design

[0142] 1. Working condition evaluation period

[0143] Collect the mill core running state parameters (including outlet temperature, circulating fan current, mill vibration, main motor current) every 10 minutes as the basis for the inference machine to judge.

[0144] 2. Negative pressure set value increase logic

[0145] When all the following conditions are met simultaneously, the negative pressure up operation is performed: the mill outlet temperature state is normal, the circulating fan current state is normal, the mill vibration state is normal, the mill main motor current state is normal, at this time the outlet negative pressure set value is increased by 5Pa, and the increase logic is not repeated within 10 minutes.

[0146] 3. Negative pressure set value maintenance logic

[0147] When any of the following conditions exists and above, the negative pressure set value remains unchanged: the mill outlet temperature is high, the circulating fan current is low, the mill vibration state is high (excluding vibration abnormality), and the main motor current is high (excluding current overrun abnormality).

[0148] 4. Negative pressure set value decrease logic

[0149] When the mill current state is "current overrun", the outlet negative pressure set value is immediately reduced by 30Pa, and the expert control system is linked to reduce the feeding amount by 4 tons of output, and enter a 10-minute adjustment locking period, during which other increase adjustment operations are suspended.

[0150] When the mill vibration state is "vibration overrun", the outlet negative pressure set value is immediately reduced by 30Pa, and enters a 10-minute adjustment locking period, during which other increase adjustment operations are suspended.

[0151] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A novel real time optimization method for raw meal of a new dry cement process, characterized by, Comprising the following steps: S1, real-time collection of raw material vertical mill operating parameters, including mill table output, inlet and outlet pressure difference, mill main motor current, circulating fan current, mill vibration value and outlet temperature; S2, filtering processing of the collected data, the filtering formula is: ； where OUT n is the output value of the nth cycle n OUT n-1 is the output value of the n-1th cycle n is the input value of the nth cycle, tz is the system calculation period, and T1 is the filtering time. S3, closed-loop control through the expert control system: Taking the inlet and outlet pressure difference as the controlled variable and the mill table output as the operating variable, the incremental PID algorithm is used to calculate the mill table output basic value; According to the circulating fan current, the mill table output is dynamically corrected: for every 1A increase in current, 0.5 tons are added, and for every 1A decrease, 0.5 tons are reduced; When the pressure difference is in the stable interval, the mill table output adjustment range is halved; S4, the mill state is evaluated once every 10 minutes through the expert optimization system, and the negative pressure set value is dynamically adjusted based on the knowledge base rules: If the outlet temperature, vibration and current are normal, the negative pressure set value is increased by 5Pa; If the main motor current is out of limit or the vibration is out of limit, the negative pressure set value is reduced by 30Pa and the feeding amount is reduced by 4 tons; S5, repeat steps S3-S4 to realize continuous optimization of output.

2. A novel real time optimization method for raw meal vertical mill of dry process cement as claimed in claim 1, wherein: Step S3 also includes safety protection logic: When the instantaneous value of the main motor current is >130A, immediately reduce the feeding amount by 4 tons; When the main motor current is >126A for 5 consecutive control periods, reduce the feeding amount by 4 tons; The above operation is only allowed to trigger once in 480 seconds.

3. A novel real time optimization method for raw meal vertical mill of dry process cement as claimed in claim 1, wherein: The knowledge base rules in step S4 include: If the average value of the mill outlet temperature is lower than the lower limit, the negative pressure is prohibited from being adjusted upward; If the circulating fan current is <80A, mark it as an abnormal discharge from the mill and prohibit the negative pressure from being adjusted upward; If the vibration value accumulates ≥5 times to the upper limit of 90% within 10 minutes, mark it as a vibration anomaly.

4. A novel real time optimization method for raw meal vertical mill of dry process cement as claimed in claim 1, wherein: The mill table output adjustment in step S3 is associated with the trend of the stockyard elevator current: The trend of the stockyard elevator current is collected every control period and is included in the mill table output calculation model in a weighted manner.

5. A novel raw meal vertical mill real time optimization system for new dry cement, applied to the method of any one of claims 1-4, characterized in that, Comprise: Data acquisition module: real-time acquisition of mill operating parameters through DCS system OPC interface; Filtering module: using filtering method to clean the collected key parameters, the filtering method meets: ； where OUT n is the output value of the nth cycle n is the output value of the nth-1 cycle n-1 is the output value of the nth cycle n is the input value of the nth cycle, tz is the system calculation cycle, and T1 is the filtering time. Expert control module: built-in PID algorithm, circulating fan current linkage correction and pressure difference interval adjustment rule; Expert optimization module: contains knowledge base and inference engine, knowledge base stores temperature, current and vibration threshold rules, and inference engine outputs negative pressure set value adjustment instruction every 10 minutes; Safety protection module: executes main motor current out-of-limit protection and vibration out-of-limit linkage control.

6. A new type of raw meal vertical mill real-time optimization system for a dry process cement according to claim 5, characterized in that: The expert control module supports manual intervention mechanism: When the operator manually modifies the mill table output, the system sets the value simultaneously and maintains it for 5 minutes, and then automatically restores the closed-loop control.

7. A new type of raw meal vertical mill real-time optimization system for a dry process cement plant according to claim 5, characterized in that: The expert optimization module includes negative pressure adjustment locking function: After executing the negative pressure reduction operation, enter the 10-minute locking period to suspend other increase adjustments.

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