Method for realizing smooth control of grate cooler in speed increasing process

Abstract

The invention provides a grate bed operation control method of a grate cooler, and belongs to the technical field of grate bed operation control. The grate cooler is started, the minimum proportional valve opening degree needed by grate bed movement is recorded, and the minimum speed of grate bed operation is recorded; gradually increasing the opening degree of the proportional valve until the grate bed runs to the maximum speed, and recording the opening degree of the proportional valve and the running speed of the grate bed in real time; dividing the opening degree of the proportional valve into N parts, and recording the opening degrees of the proportional valve at the end points of different intervals and the running speed of the grate bed; according to the recorded relation between the opening degrees of the proportional valves and the running speed of the grate bed, the ratios of the opening degrees of the proportional valves corresponding to the different speed intervals are calculated, and the relation between the running speed of the grate bed and the opening degrees of the proportional valves is determined according to the ratios; after the speed is set, the opening degree of the proportional valve is adjusted according to the relation between the running speed of the grate bed and the opening degree of the proportional valve and the running speed of the current grate bed. The operation stability of the grate bed is improved.

Description

Technical Field

[0001] This invention belongs to the field of grate operation control technology. Specifically, this invention relates to a method for achieving smooth control of a grate cooler during the speed-up process. Background Technology

[0002] Currently, grate coolers have become an indispensable key piece of equipment in cement clinker production lines. Their functions span multiple core stages, including cooling, heat recovery, and conveying. Therefore, the operating efficiency, cooling effect, equipment stability, and safety of the grate cooler directly affect the production line's capacity and energy consumption. With the development of cement production technology and the urgent need for energy conservation and consumption reduction, the shortcomings of third-generation grate coolers in cement production processes, such as severe material leakage, high dust pollution, severe grate wear, and high maintenance costs, are increasingly failing to meet current cement production needs. Simultaneously, with increasing environmental protection requirements and the strengthening of the trend towards larger, more automated, and intelligent equipment, cement production enterprises are gradually adopting fourth-generation grate coolers with higher automation and better operating efficiency in the process of building or upgrading cement production lines. The fourth-generation grate cooler achieves rapid clinker cooling and efficient heat utilization through the synergistic effect of "grate bed conveying + zoned forced-air cooling + high-efficiency heat recovery," with the core being optimized airflow distribution and material layer control. Its core workflow can be divided into three key stages: high-temperature clinker receiving and initial cooling, step conveying and segmented cooling, and final cooling and discharge. Each stage is closely connected to form a closed-loop cooling system.

[0003] Chinese Patent 103363812B provides a control method for a cement clinker grate cooler. Variable selection: The pressure of the first section of the grate cooler is selected as the controlled variable, and the speed of the first section of the grate is selected as the operated variable; Data preprocessing: The raw data of the collected pressure of the first section of the grate is filtered; A model-free adaptive controller for the pressure of the first section of the grate is designed.

[0004] Existing technology does not take into account the mechanical vibration of the grate during speed increase or decrease, which will affect the operational stability of the grate. Summary of the Invention

[0005] The present invention aims to provide a method for achieving smooth control of the grate cooler during the speed-up process, so as to improve the operational stability of the grate bed.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for smoothly controlling the speed increase of a grate cooler, comprising the following steps:

[0008] Step 1: In no-load mode, start the grate cooler, record the minimum proportional valve opening required for the grate bed to move, and record the minimum speed at which the grate bed runs;

[0009] Step 2: Gradually increase the opening of the proportional valve from 0-100%, and record the running speed of the grate at different openings of the proportional valve in real time.

[0010] Step 3: Divide the opening of the proportional valve into N parts, and record the opening of the proportional valve and the running speed of the grate at the endpoints of different sections.

[0011] Step 4: Based on the recorded relationship between the proportional valve opening and the grate's running speed, calculate the ratio of the proportional valve opening corresponding to different speed ranges, and determine the relationship between the grate's running speed and the proportional valve opening based on the ratio.

[0012] Step 5: After setting the grate speed, first, based on the relationship between the grate's running speed and the proportional valve opening, quickly open the proportional valve to the opening required for the current speed.

[0013] In step two, the relationship between the opening degree of the proportional valve and the running speed of the grate is recorded by controlling the forward or backward movement of the grate.

[0014] In step three, the opening degree of the proportional valve is divided into 5 parts.

[0015] In step four, the method for calculating the ratio of the proportional valve opening degree in different speed ranges is as follows: calculate the ratio of the difference in the grate running speed corresponding to the two endpoints in the same speed range to the difference in the proportional valve opening degree corresponding to the two endpoints.

[0016] In step five, the speed range of the set speed is determined, and then combined with the current speed range of the grate, the proportional valve is adjusted according to the ratio of the proportional valve opening corresponding to different speed ranges until the grate running speed reaches the set speed.

[0017] In step five, if the speed is set to zero, then the proportional valve opening is set to zero.

[0018] When the grate reaches the set speed and stabilizes, a significant change in load will inevitably cause a large fluctuation in the grate speed. To ensure smooth speed adjustment, a speed-up buffer program can be used for adjustment.

[0019] The speed-up buffer program adjusts the sudden changes in the grate running speed by setting a buffer coefficient and combining it with the differential ratio calculation logic.

[0020] A grate cooler, using the aforementioned method to achieve smooth control of the grate cooler during the speed-up process.

[0021] The technical effects of this invention are as follows:

[0022] (1) This invention divides the speed and opening intervals by segmented control strategy and calculates the interval ratio, so that the grate running speed and the proportional valve opening form a precise linear correspondence in different speed ranges. This solves the problem of large opening adjustment error under single control logic, significantly improves the proportional valve opening control accuracy, and ensures that the grate speed quickly approaches the set value.

[0023] (2) The present invention designs a speed-up buffer program for sudden load changes. By increasing the buffer coefficient in stages, the speed adjustment difference is proportionally scaled to avoid mechanical vibration caused by large fluctuations in the proportional valve. This effectively ensures the stability of the grate bed during constant operation or load changes and reduces equipment wear.

[0024] (3) The present invention covers targeted control logic for three working conditions of the grate bed: forward, backward and stop. The control logic is constructed by combining multi-endpoint measured data to adapt to different operating requirements and improve the control adaptability and reliability under different working conditions.

[0025] (4) This invention optimizes the operating performance of the grate cooler and extends the service life of the equipment. Attached Figure Description

[0026] This manual includes the following figures, which illustrate the following:

[0027] Figure 1 This is a flowchart of a method for achieving smooth control of a grate cooler during the acceleration process according to the present invention;

[0028] Figure 2 This invention provides a grate bed forward acceleration buffer program for a method of smoothly controlling the acceleration of a grate cooler during the acceleration process.

[0029] Figure 3 This invention relates to a grate bed retraction and acceleration buffer program for a method of smoothly controlling the acceleration of a grate cooler during the acceleration process. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0031] This invention provides a method for smoothly controlling the speed increase of a grate cooler, comprising the following steps:

[0032] Step 1: Start the grate cooler, record the minimum proportional valve opening required for the grate bed to move, and record the minimum speed at which the grate bed runs;

[0033] Step 2: Gradually increase the opening of the proportional valve until the grate reaches its maximum speed, and record the opening of the proportional valve and the running speed of the grate in real time;

[0034] Step 3: Divide the opening of the proportional valve into N parts, and record the opening of the proportional valve and the running speed of the grate at the endpoints of different sections.

[0035] Step 4: Based on the recorded relationship between the proportional valve opening and the grate's running speed, calculate the ratio of the proportional valve opening corresponding to different speed ranges, and determine the relationship between the grate's running speed and the proportional valve opening based on the ratio.

[0036] Step 5: After setting the speed, adjust the proportional valve opening based on the relationship between the grate's running speed and the proportional valve opening, and in conjunction with the current grate's running speed.

[0037] In step two, the relationship between the opening degree of the proportional valve and the running speed of the grate is recorded by controlling the forward or backward movement of the grate.

[0038] In step three, the opening degree of the proportional valve is divided into 5 parts.

[0039] In step four, the method for calculating the ratio of the proportional valve opening degree in different speed ranges is as follows: calculate the ratio of the difference in the grate running speed corresponding to the two endpoints in the same speed range to the difference in the proportional valve opening degree corresponding to the two endpoints.

[0040] In step five, the speed range of the set speed is determined, and then combined with the current speed range of the grate, the proportional valve is adjusted according to the ratio of the proportional valve opening corresponding to different speed ranges until the grate running speed reaches the set speed.

[0041] In step five, if the speed is set to zero, then the proportional valve opening is set to zero.

[0042] When the grate reaches the set speed and stabilizes, if there is a significant change in load, the speed will be adjusted through a speed-up buffering program.

[0043] The speed-up buffer program adjusts the sudden changes in the grate running speed by setting a buffer coefficient and combining it with the differential ratio calculation logic.

[0044] A grate cooler, using the aforementioned method to achieve smooth control of the grate cooler during the speed-up process.

[0045] The present invention describes in detail a method for achieving smooth control of a grate cooler during the acceleration process.

[0046] To ensure the smooth operation of the grate and improve the accuracy of the proportional valve opening, the process of converting the set speed into the proportional valve opening is controlled in segments.

[0047] Specifically, after starting the grate cooler, when the grate just begins to move, the current opening value of the proportional valve (MV1) and the running speed of the grate are recorded. In the embodiment of the present invention, the running speed of the grate when it moves forward (FW_SPD1) is recorded. At this time, the grate runs at the slowest speed, and the opening of the proportional valve at this time is the effective opening to ensure the operation of the grate.

[0048] Then, gradually increase the proportional valve opening, ensuring the smooth operation of the grate. Record the current opening value of the proportional valve and the running speed of the grate in real time. Adjust the proportional valve opening until the running speed of the grate reaches its maximum. Set the opening of the proportional valve to N parts, that is, take N+1 endpoints, and record the proportional valve opening and the running speed of the grate corresponding to each endpoint, thereby determining N intervals.

[0049] Based on the proportional valve opening and grate operating speed recorded at each endpoint, calculate the ratio of the proportional valve opening corresponding to different intervals. That is, calculate the ratio of the difference in grate operating speed between the two endpoints within the same speed interval to the difference in the proportional valve opening between the two endpoints. Taking one interval as an example, the calculation formula is explained below:

[0050] Ratio k = (FW_SPD2 - FW_SPD1) ÷ (MV2 - MV1)

[0051] Where FW_SPD2 and FW_SPD1 are the grate running speeds at the two ends of the first interval, respectively, MV2 is the proportional valve opening corresponding to the grate running speed FW_SPD2, and MV1 is the proportional valve opening corresponding to the grate running speed FW_SPD1.

[0052] At this point, within different speed ranges, the operating speed of the grate bed is linearly related to the opening degree of the proportional valve.

[0053] After the grate cooler is started, it first checks if the grate's running speed setting is equal to 0. If it is 0, the control output of the proportional valve is set to 0. If the speed setting is < 0, the grate is controlled to move backward. If the speed setting is > 0, the grate is controlled to move forward. Specifically, the speed range of the set speed is determined, and then, combined with the current speed range of the grate's running speed, the proportional valve is adjusted according to the ratio of the proportional valve opening corresponding to different speed ranges until the grate's running speed reaches the set speed. If the grate speed set value (SPD) is between FW_SPD1 and FW_SPD2, the corresponding valve opening (Out) is MV1 + speed deviation × deviation rate, i.e., OUT = MV1 + (SPD - FW_SPD1) × k.

[0054] In an embodiment of the present invention, the speed range is divided into 5 intervals by measuring the ratio between the opening of 6 proportional valves and the corresponding forward and backward speeds of the grate. As shown in Table 1, the forward and backward speeds of the grate are measured when the valve opening values ​​are 8, 22, 30, 35, 40, and 45.

[0055]

[0056] Table 1

[0057] When the grate is running at a constant speed, a sudden and significant change in load can cause a large adjustment in the proportional valve, leading to vibration in the mechanical parts of the grate cooler and decreased stability of the grate operation. To address this, a speed-up buffering program is used for adjustment, the specific program of which is as follows: Figure 2 , Figure 3 As shown below, Figure 2 , Figure 3 Describe it.

[0058] Figure 2 The program includes the setting of the forward acceleration buffer coefficient and the forward acceleration buffer operation logic.

[0059] The specific setting of the acceleration buffer coefficient is as follows: A phased incremental buffer coefficient is generated from 0 to 1. Initial stage: When #IN_ADD=0.0, 0.0 is assigned to the buffer coefficient (#factU) via NOT+MOVE. Phased accumulation: When #factU ≤ 0.3333, #factU += #STEP_U1; when 0.3333 < #factU ≤ 0.6666, #factU += #STEP_U2; when 0.6666 < #factU ≤ 1.0, #factU += #STEP_U3; Saturation stage: When #factU ≥ 1.0, 1.0 is assigned to #factU via MOVE, and the coefficient no longer increases. #IN_ADD represents the overall valve opening. Because PID control is involved in the calculation during both forward and backward movements, this value is the sum of the initial valve opening at a certain speed and the opening required by the PID calculation.

[0060] The forward acceleration buffer operation logic is as follows: Using the buffer coefficient (#factU), the final output #OUT_R is smoothly calculated. Operation logic:

[0061] #RED_int = #IN_ADD - #OUT_int

[0062] #TEMP4 = #RED_int × #factU

[0063] #OUT_R = #TEMP4 + #OUT_int

[0064] By using a buffer coefficient to scale the difference between the target and the current value, and then adding it to the current output, a smooth transition in the acceleration process is achieved.

[0065] Figure 3 The program includes the setting of the backward acceleration buffer coefficient and the backward acceleration buffer operation logic.

[0066] The backflip acceleration buffer coefficient is specifically set as follows: It is an incremental buffer coefficient from 0 to 1 generated during backflip acceleration. Initial stage: When #IN_ADD < 0.0, 0.0 is assigned to #factF via NOT+MOVE. Accumulation stage: #factF += #STEP_F, continuously incrementing. Saturation stage: When #factF > 1.0, 1.0 is assigned to #factF via MOVE.

[0067] The logic for the backward acceleration buffer operation is as follows: using the buffer coefficient #factF, a smooth output of backward acceleration is achieved.

[0068] #RED_int = #IN_ADD + #OUT_int

[0069] #TEMP4 = #RED_int × #factF

[0070] #OUT_R &= #TEMP4 - #OUT_int

[0071] In the above operational logic, #RED_int is the total dead zone input, #OUT_int is the initial valve opening, and #factU is the starting acceleration.

[0072] The beneficial effects of the present invention are described in detail below.

[0073] This invention divides the speed and opening intervals by using a segmented control strategy and calculates the interval ratio, so that the grate running speed and the proportional valve opening form a precise linear correspondence within different speed ranges. This solves the problem of large opening adjustment error under a single control logic, significantly improves the proportional valve opening control accuracy, and ensures that the grate speed quickly approaches the set value.

[0074] This invention designs a speed-up buffer program to address sudden load changes. By progressively increasing the buffer coefficient in stages, the speed adjustment difference is scaled proportionally to avoid mechanical vibration caused by large fluctuations in the proportional valve. This effectively ensures the stability of the grate during constant operation or load changes and reduces equipment wear.

[0075] This invention covers targeted control logic for three working conditions of the grate bed: forward, backward, and standby. The control logic is constructed by combining multi-endpoint measured data to adapt to different operating requirements and improve the control adaptability and reliability under different working conditions.

[0076] This invention optimizes the operating performance of the grate cooler and extends the service life of the equipment.

[0077] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for controlling the operation of a grate bed in a grate cooler, characterized in that: Includes the following steps: Step 1: Start the grate cooler, record the minimum proportional valve opening required for the grate bed to move, and record the minimum speed at which the grate bed runs; Step 2: Gradually increase the opening of the proportional valve until the grate reaches its maximum speed, and record the opening of the proportional valve and the running speed of the grate in real time; Step 3: Divide the opening of the proportional valve into N parts, and record the opening of the proportional valve and the running speed of the grate at the endpoints of different sections; Step 4: Based on the recorded relationship between the proportional valve opening and the grate's running speed, calculate the ratio of the proportional valve opening corresponding to different speed ranges, and determine the relationship between the grate's running speed and the proportional valve opening based on the ratio. Step 5: After setting the speed, adjust the proportional valve opening based on the relationship between the grate's running speed and the proportional valve opening, and in conjunction with the current grate's running speed.

2. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: In step two, the relationship between the opening degree of the proportional valve and the running speed of the grate is recorded by controlling the forward or backward movement of the grate.

3. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: In step three, the opening degree of the proportional valve is divided into 5 parts.

4. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: In step four, the method for calculating the ratio of the proportional valve opening degree in different speed ranges is as follows: calculate the ratio of the difference in the grate running speed corresponding to the two endpoints in the same speed range to the difference in the proportional valve opening degree corresponding to the two endpoints.

5. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: In step five, the speed range of the set speed is determined, and then combined with the current speed range of the grate, the proportional valve is adjusted according to the ratio of the proportional valve opening corresponding to different speed ranges until the grate running speed reaches the set speed.

6. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: In step five, if the speed is set to zero, then the proportional valve opening is set to zero.

7. The method for controlling the operation of the grate bed in a grate cooler as described in claim 1, characterized in that: When the grate reaches the set speed and stabilizes, if there is a significant change in load, the speed will be adjusted through a speed-up buffering program.

8. The method for controlling the operation of the grate bed in a grate cooler as described in claim 7, characterized in that: The speed-up buffer program adjusts the sudden changes in the grate running speed by setting a buffer coefficient and combining it with the differential ratio calculation logic.

9. A grate cooler, using a method for grate bed operation control as described in any one of claims 1-8.

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