Intelligent control method for adding water to sintering mixture

Abstract

The present application belongs to the technical field of metallurgical sintering automatic control, and particularly relates to a kind of intelligent control method of sintering mixture water adding. Including the following steps: S1, obtaining the flow parameter of mixture in initial mixing, mixing and second mixing;S2, calculating the estimated value H of original moisture of mixture after initial mixing G , with the larger value in H G As the original moisture reference value H1 of mixing water control;S3, calculating the set value Q1 of mixing water quantity, and according to Q1, the water adding adjusting valve of mixing machine is controlled with delay;S4, calculating the set value Q2 of second mixing water quantity, comparing H3 with T, according to the deviation of both, fine tuning Q2 to obtain ΔQ2, and according to the value of Q2+ΔQ2, the water adding adjusting valve of second mixing machine is controlled with delay. The present application takes the larger value of theoretical moisture and measured moisture as the original moisture reference, effectively prevents the overwatering caused by low measurement value, and guarantees the control safety from the source.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology for metallurgical sintering, and particularly relates to an intelligent control method for adding water to sintering mixtures. Background Technology

[0002] The moisture content of the sintering mixture is a key parameter affecting the permeability, vertical sintering speed, and sinter quality during the sintering process. Currently, a common control method involves installing a moisture meter after the primary and secondary mixing stages for feedback adjustment, but this method suffers from significant lag. Attempts have also been made to install a moisture meter before the primary mixing stage for feedforward control, but because the mixture is not yet fully homogenized, has a complex composition, and is affected by dust and uneven material flow, the measurement value from a single moisture meter fluctuates greatly and has low reliability. Directly using this for control can easily lead to excessive or insufficient water addition. Furthermore, existing systems fail to fully utilize precise upstream batching scale data and incoming laboratory test data, resulting in a coarse control model that makes precise water addition difficult. Summary of the Invention

[0003] The purpose of this invention is to provide an intelligent control method for adding water to sintering mixtures, so as to solve the problems existing in the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A method for intelligent control of water addition to sintering mixtures includes the following steps:

[0006] S1. Obtain the measured moisture content H0 of the initial mixture, the feed flow rate W1 of the first mixer, the measured moisture content H2 of the initial mixture, the feed flow rate W2 of the second mixer, the measured moisture content H3 of the second mixture, and obtain the proportion R of each raw material constituting the mixture. i and its original moisture M i ;

[0007] S2, based on R i M i Calculate the estimated initial moisture content H of the mixture after initial mixing. G , will H G The larger of the two values ​​is compared with H0 and used as the original moisture baseline value H1 for mixed water control.

[0008] S3. Based on W1, H1 and the preset target moisture rate T, calculate a set value Q1 for the amount of water to be added, and control a mixer water addition regulating valve according to a delay of Q1.

[0009] S4. Based on W2, H2 and T, calculate the set value Q2 for the secondary mixer water addition. Compare H3 and T, and fine-tune Q2 according to the deviation between the two to obtain ΔQ2. Then, control the secondary mixer water addition regulating valve according to the value of Q2+ΔQ2 with a delay.

[0010] Furthermore, in step S1, the original moisture content of each raw material comes from the periodic sampling and testing results of each raw material pile, and is stored in association with the raw material pile location information. The corresponding original moisture content is automatically retrieved according to the raw material pile location corresponding to the current production batch.

[0011] Furthermore, in step S2, the estimated value of the initial moisture content of the mixture after initial mixing is calculated using the following formula:

[0012] ;

[0013] Among them, H G R is an estimated value of the initial moisture content of the mixture after initial mixing. i Let M be the mass ratio of the i-th raw material in the initial mixture. i Let be the initial moisture content of the i-th raw material.

[0014] Furthermore, in step S3, the set value for the amount of water to be mixed is calculated using the following formula:

[0015] ;

[0016] Where Q1 is a set value for the amount of water added, T is the target moisture content, W1 is the feed flow rate of the mixer, H1 is the original moisture reference value for the water addition control, and K1 is a correction coefficient for the amount of water added.

[0017] Furthermore, in step S4, the set value for the amount of water added to the second mixture is calculated using the following formula:

[0018] ;

[0019] Where Q2 is the set value of water added for the second mixing, T is the target moisture content, W2 is the feed flow rate of the second mixer, H2 is the measured moisture content of the mixture after the first mixing, and K2 is the correction coefficient for water added for the second mixing.

[0020] Furthermore, in step S4, the fine-tuning adopts a PID control algorithm, the input of which is the deviation e between H3 and T, and the output is the adjustment amount ΔQ2 of the set value Q2 of the mixed water addition.

[0021] Furthermore, it also includes interlocking protection steps: when a fault shutdown signal is detected in the feeding belt, primary mixer, or secondary mixer, or when an empty signal is detected in the belt scale, a shutdown command is output to all water supply regulating valves and quick shut-off valves.

[0022] The present invention has the following beneficial effects:

[0023] 1. This invention uses the larger of the theoretical moisture content calculated based on the raw material ratio and test data and the actual moisture content measured before mixing as the original moisture standard, effectively preventing excessive water addition due to low measured values, and ensuring safety control from the source.

[0024] 2. A composite control structure combining feedforward calculation and feedback fine-tuning is adopted. The first mixing water addition responds quickly to batch changes, while the second mixing water addition is precisely corrected according to the final moisture deviation, significantly improving control accuracy and stability.

[0025] 3. Set up interlock protection steps to quickly cut off the water supply in case of failure or material shortage, ensuring production safety. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0027] Example 1:

[0028] A method for intelligent control of water addition to sintering mixtures includes the following steps:

[0029] S1. Obtain the measured moisture content H0 of the initial mixture, the feed flow rate W1 of the first mixer, the measured moisture content H2 of the initial mixture, the feed flow rate W2 of the second mixer, the measured moisture content H3 of the second mixture, and obtain the proportion R of each raw material constituting the mixture. i and its original moisture M i .

[0030] H0, H2, and H3 were detected by infrared moisture analyzers installed at the feed end, discharge end, and discharge end of the first mixer, respectively; W1 and W2 were detected by belt scales installed at the feed end and discharge end of the first mixer, respectively.

[0031] The original moisture content M of each raw material i It is derived from the periodic sampling and testing results of each raw material pile, and is stored in association with the raw material pile location information. The corresponding original moisture content is automatically retrieved according to the raw material pile location corresponding to the current production batch.

[0032] The proportions and initial moisture content of each raw material are shown in Table 1 below:

[0033] Table 1: Proportions and Initial Moisture Content of Each Raw Material

[0034] raw material Mass ratio Rᵢ (%) Original moisture content Mᵢ (%) Iron ore powder A 40 8 Iron ore powder B 25 6.5 limestone 8 1.2 Raw dolomite powder 7 1 Return to ore 12 5 Mixed coke powder 8 2

[0035] The currently collected real-time data are: H0 = 6.0%, W1 = 350 t / h. The target moisture content T is 7.2%, with an error controlled within ±0.05%.

[0036] S2, based on R i M i Calculate the estimated initial moisture content H of the mixture after initial mixing.G , will H G The larger of the two values, H0 and H1, is used as the initial moisture reference value for water control in the initial mixing process. The estimated initial moisture content of the mixture after initial mixing is calculated using the following formula:

[0037] ;

[0038] Among them, H G R is an estimated value of the initial moisture content of the mixture after initial mixing. i Let M be the mass ratio of the i-th raw material in the initial mixture. i Let be the initial moisture content of the i-th raw material.

[0039] Calculations show that H G The value is 5.751%. Compared with H0, the larger value is 6.0%, so H1 = 6.0%.

[0040] S3. Based on W1, H1, and the preset target moisture content T, calculate a mixing water volume setpoint Q1, and control a mixer water addition regulating valve according to a delay of Q1; the mixing water volume setpoint is calculated using the following formula:

[0041] ;

[0042] Wherein, Q1 is a set value for the amount of water added, T is the target moisture rate, set to 7.2%, W1 is the feed flow rate of the mixer, H1 is the original moisture baseline value for the water addition control, and K1 is a correction coefficient for the amount of water added, with a value of 1.02, to compensate for moisture evaporation loss.

[0043] The calculated value of Q1 is 4.62 t / h. The PLC outputs an analog signal to a mixing water regulating valve, sets the flow rate to 4.62 t / h, and the valve position automatically adjusts to the corresponding opening degree.

[0044] S4. Based on W2, H2, and T, calculate the setpoint Q2 for the secondary mixer's water addition. Compare H3 with T, and fine-tune Q2 according to the deviation between the two to obtain ΔQ2. Then, control the secondary mixer's water addition regulating valve based on the value of Q2 + ΔQ2 with a delay. The setpoint for the secondary mixer's water addition is calculated using the following formula:

[0045] ;

[0046] Where Q2 is the set value of water added for the second mixing, T is the target moisture content, W2 is the feed flow rate of the second mixer, which is 353.8 t / h in actual measurement, H2 is the measured moisture content of the mixture after the first mixing, and K2 is the correction coefficient for water added for the second mixing, which is 0.98, to compensate for losses, errors, etc.

[0047] The result shows that H2 = 7.1%, which is less than T. This indicates that the mixture has not reached the target value due to factors such as moisture evaporation and water pressure fluctuations. Water needs to be added, and Q2 is calculated to be 0.37 t / h.

[0048] Continue fine-tuning Q2, and H3 = 7.28% is detected. Its deviation from T is e = T - H3 = -0.08%. Use the PID algorithm, only enable the proportional term, the proportional coefficient P = 100, and the integral and derivative terms are 0.

[0049] Therefore, ΔQ2=P×e=100×(-0.0008)=-0.08t / h, indicating that during the secondary mixing process, due to other reasons such as a sudden increase in water pressure, the mixture after secondary mixing is too wet, and the amount of water added needs to be reduced appropriately.

[0050] Q2+ΔQ2=0.37t / h-0.08t / h=0.15t / h.

[0051] The PLC outputs a signal to the two-stage mixing water regulating valve to replenish water at a flow rate of 0.15t / h.

[0052] It should be noted that, due to the time delay in the material's transport from the detection point (such as a belt scale or moisture meter) to the water addition point of the mixer, the water addition control of the primary and secondary mixers needs to be set with appropriate delay times based on the material conveying speed and distance to ensure that the water addition action is synchronized with the material's arrival, avoiding water addition that is too early or too late. The delay time can be pre-calculated based on parameters such as belt length and belt speed, or calibrated experimentally.

[0053] Example 2:

[0054] This embodiment provides a method for intelligent control of water addition to sintering mixtures. The method steps are basically the same as those in Embodiment 1, except that:

[0055] In step S4, H2 is detected to be 7.16%. H2 is within the error range of T, indicating that the mixture has reached the target value and no further water is needed. Therefore, Q2 = 0 t / h.

[0056] Continue fine-tuning Q2, and H3 = 7.13% is detected. Its deviation from T is e = T - H3 = 0.07%. The PID algorithm is adopted, with only the proportional term enabled, the proportional coefficient P = 100, and the integral and derivative terms are 0.

[0057] Therefore, ΔQ2=P×e=100×0.0007=0.07t / h, indicating that the water added during the second mixing process still has a small amount of evaporation loss or sudden drop in water pressure, which causes the mixture after the second mixing to be too dry and requires further water replenishment.

[0058] Q2+ΔQ2=0t / h+0.07t / h=0.07t / h.

[0059] The PLC outputs a signal to the two-stage mixing water regulating valve to replenish water at a flow rate of 0.07 t / h.

[0060] Example 3:

[0061] This embodiment provides a method for intelligent control of water addition to sintering mixtures. The method steps are basically the same as those in Embodiment 1, except that:

[0062] In step S4, H2 was detected to be 7.1%, which is less than T, indicating that the mixture has not reached the target value and water needs to be added. Q2 was calculated to be 0.37 t / h.

[0063] Continue fine-tuning Q2, and H3 = 7.13% is detected. Its deviation from T is e = T - H3 = 0.07%. The PID algorithm is adopted, with only the proportional term enabled, the proportional coefficient P = 100, and the integral and derivative terms are 0.

[0064] Therefore, ΔQ2=P×e=100×0.0007=0.07t / h, indicating that the water added during the second mixing process still has a small amount of evaporation loss or sudden drop in water pressure, which causes the mixture after the second mixing to be too dry and requires further water replenishment.

[0065] Q2+ΔQ2=0.37t / h+0.07t / h=0.44t / h.

[0066] The PLC outputs a signal to the two-stage mixing water regulating valve to replenish water at a flow rate of 0.44 t / h.

[0067] Example 4:

[0068] This embodiment provides a method for intelligent control of water addition to sintering mixtures. The method steps are basically the same as those in Embodiment 1, except that:

[0069] Interlock protection steps: When a fault shutdown signal is detected in the feeding belt, primary mixer, or secondary mixer, or when an empty signal is detected in the belt scale, a shutdown command is output to all water supply regulating valves and quick shut-off valves.

[0070] Similarly, since there is a certain time delay in the material being conveyed from the detection point, such as the belt scale, to the water addition point of the mixer, the shut-off of the water addition control for the primary and secondary mixers needs to be set with appropriate delay times based on the material conveying speed and distance to ensure that all materials have been watered and to avoid the water addition shut-off action being too early or too late. The delay time can be pre-calculated based on parameters such as belt length and belt speed or calibrated experimentally.

[0071] In the event of a malfunction and shutdown, the water supply regulating valve and the quick-shut-off valve should be immediately shut off as an emergency measure.

[0072] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention.

[0073] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for intelligent control of water addition to sintering mixtures, characterized in that, Includes the following steps: S1. Obtain the measured moisture content H0 of the initial mixture, the feed flow rate W1 of the first mixer, the measured moisture content H2 of the initial mixture, the feed flow rate W2 of the second mixer, the measured moisture content H3 of the second mixture, and obtain the proportion R of each raw material constituting the mixture. i and its original moisture M i ; S2, based on R i M i Calculate the estimated initial moisture content H of the mixture after initial mixing. G , will H G The larger of the two values ​​is compared with H0 and used as the original moisture baseline value H1 for mixed water control. S3. Based on W1, H1 and the preset target moisture rate T, calculate a set value Q1 for the amount of water to be added, and control a mixer water addition regulating valve according to a delay of Q1. S4. Based on W2, H2 and T, calculate the set value Q2 for the secondary mixer water addition. Compare H3 and T, and fine-tune Q2 according to the deviation between the two to obtain ΔQ2. Then, control the secondary mixer water addition regulating valve according to the value of Q2+ΔQ2 with a delay.

2. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, In step S1, the original moisture content of each raw material is obtained from the periodic sampling and testing results of each raw material pile, and is stored in association with the raw material pile location information. The corresponding original moisture content is automatically retrieved according to the raw material pile location corresponding to the current production batch.

3. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, In step S2, the estimated initial moisture content of the premixed mixture is calculated using the following formula: ； Among them, H G R is an estimated value of the initial moisture content of the mixture after initial mixing. i Let M be the mass ratio of the i-th raw material in the initial mixture. i Let be the initial moisture content of the i-th raw material.

4. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, In step S3, the set value of the mixed water volume is calculated according to the following formula: ； Where Q1 is a set value for the amount of water added, T is the target moisture content, W1 is the feed flow rate of the mixer, H1 is the original moisture reference value for the water addition control, and K1 is a correction coefficient for the amount of water added.

5. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, In step S4, the set value for the amount of water added in the two mixtures is calculated using the following formula: ； Where Q2 is the set value of water added for the second mixing, T is the target moisture content, W2 is the feed flow rate of the second mixer, H2 is the measured moisture content of the mixture after the first mixing, and K2 is the correction coefficient for water added for the second mixing.

6. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, In step S4, the fine-tuning is performed using a PID control algorithm, with the input being the deviation e between H3 and T, and the output being the adjustment amount ΔQ2 to the set value Q2 of the mixed water addition.

7. The intelligent control method for adding water to sintering mixture according to claim 1, characterized in that, It also includes interlock protection steps: when a fault shutdown signal is detected in the feeding belt, the primary mixer, or the secondary mixer, or when an empty signal is detected in the belt scale, a shutdown command is output to all water regulating valves and quick shut-off valves.

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