Control method and device for powder collapse condition during operation of powder feeder in central storage type powder making system

Abstract

The present application relates to the technical field of powder feeders of thermal power units, and discloses a method and device for controlling a powder collapse condition during operation of a powder feeder of a central storage type powder making system, the method comprising: S1: acquiring operating data of a first powder feeder, wherein the operating data of the first powder feeder comprises primary air-powder velocity data and / or primary air-powder outlet temperature data; S2: obtaining first powder collapse condition data by calculating according to a first calculation method based on the operating data of the first powder feeder; obtaining a first bias instruction and a first execution time by calculating according to a second calculation method based on the first powder collapse condition data corresponding to the generation of the powder collapse phenomenon; S3: controlling the speed of the powder feeder to slow down to the parameter of the first bias instruction and continuing for the first execution time; S4: controlling the speed of the powder feeder to return to the state before executing the first bias instruction, thereby greatly reducing the probability of powder collapse occurring in the powder feeder and improving the safety and stability of the thermal power unit.

Description

Technical Field

[0001] The present application relates to the field of powder feeders for thermal power units, and in particular to a method and device for controlling a powder collapse condition during operation of a powder feeder for a central storage type powder making system. Background Art

[0002] The central storage pulverizing system for a thermal power unit is also known as an intermediate storage pulverizing system. In this system, the ground coal is first stored in a silo and then fed into the furnace based on load requirements. In this system, if the desiccant and evaporated water vapor from the fuel are ultimately fed into the boiler's combustion chamber, it is called a closed pulverizing system. If the evaporated water vapor and desiccant from the fuel are not fed into the combustion chamber but are directly discharged into the atmosphere, it is called an open pulverizing system.

[0003] While the central storage pulverizing system offers the advantage of fast load and pressure response, it can sometimes experience feeder blockage or collapse, leading to unstable coordination and even oscillation. In severe cases, this can threaten the safety of the thermal power unit. When a feeder collapses, the main steam pressure rapidly increases by approximately 0.7 MPa within 30-60 seconds. If two feeders collapse simultaneously, the main steam pressure rapidly increases by approximately 1.4 MPa within 30-60 seconds. This is particularly true when the thermal power unit is operating at high load, and encountering a collapse condition can easily lead to overpressure. In severe cases, this can trigger the safety valve, compromising the unit's safety.

[0004] Therefore, once the powder feeder shows signs of powder collapse, the operator will immediately adjust the speed of the powder feeder or shut down the powder feeder to prevent the powder collapse from worsening. Therefore, it is necessary to reduce the probability of powder collapse in the storage powder making system of the thermal power unit. Summary of the Invention

[0005] In order to reduce the probability of powder collapse in the central storage type powder making system of the thermal power unit, the present application provides a method and device for controlling the powder collapse condition during the operation of the powder feeder of the central storage type powder making system.

[0006] On the one hand, the present application provides a method for controlling the powder collapse condition during the operation of a powder feeder in a central storage type powder making system, which adopts the following technical solution:

[0007] A method for controlling a powder collapse condition during operation of a powder feeder in a central storage type powder making system comprises the following steps:

[0008] S1: Acquire operating data of a first powder feeder, wherein the operating data of the first powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data;

[0009] S2: Calculating first powder collapse condition data according to a first calculation method based on the first powder feeder operation data; calculating a first bias instruction and a first execution time according to a second calculation method based on the first powder collapse condition data corresponding to the powder collapse phenomenon;

[0010] S3: controlling the speed of the powder feeder to decrease to a parameter of the first bias instruction and continuing for the first execution time;

[0011] S4: controlling the rotation speed of the powder feeder to return to the state before executing the first bias instruction.

[0012] By adopting the above technical solution, a bias, namely the first bias instruction, is added to the automatic control loop of the powder feeder speed instruction. The first bias instruction is to reduce the speed of the powder feeder, and the amount of reduction is the bias amount. When signs of powder collapse appear, that is, the primary air powder speed is lower than a set value or the primary air powder outlet temperature is lower than another set value, the powder feeder is controlled to slow down and continue for a first execution time, and then the speed of the powder feeder is restored; the probability of powder collapse in the powder feeder is greatly reduced, and many impending powder collapse phenomena are curbed in the early stages, which greatly reduces the workload of operating personnel and improves the safety and stability of the thermal power unit.

[0013] Optionally, the method further comprises the following steps:

[0014] S5: controlling the speed of the powder feeder to continue for the first execution time after recovery;

[0015] S6: Acquire operating data of the second powder feeder, wherein the operating data of the second powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data;

[0016] S7: Calculating second powder collapse operating condition data according to the first calculation method based on the second powder feeder operating data; calculating a second bias instruction and a second execution time according to the second calculation method based on the second powder collapse operating condition data corresponding to the powder collapse phenomenon;

[0017] S8: controlling the speed of the powder feeder to decrease to a parameter of the second bias instruction and continuing for the second execution time;

[0018] S9: controlling the speed of the powder feeder to return to the state before executing the second bias instruction;

[0019] S10: Execute S5-S9 in a loop until the latest second powder collapse working condition data corresponds to no powder collapse.

[0020] By adopting the above technical solution, after executing the first bias instruction for the first execution time, if there are still signs of powder collapse, the first execution time will be delayed after the speed of the powder feeder is restored, and then the second bias instruction will be executed to slow down the powder feeder and continue for the second execution time, and then the speed will be restored. This process will be repeated until the primary air powder speed or the primary air powder outlet temperature reaches the corresponding parameter requirements, and the powder feeder operates normally, and the second bias instruction will no longer be executed.

[0021] Optionally, the first calculation method includes the following steps:

[0022] If the first powder feeder operation data includes primary air-powder speed data, the first powder feeder operation data is compared with a set first speed data; if the first powder feeder operation data is less than the first speed data, the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output;

[0023] Alternatively, if the first powder feeder operation data includes primary air powder outlet temperature data, the first powder feeding operation data is compared with a set first temperature data; if the first powder feeding operation data is lower than the first temperature data, the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output;

[0024] Alternatively, if the first powder feeder operation data includes primary air powder speed data and primary air powder outlet temperature data, the wind speed difference a between the primary air powder speed data and the set first wind speed data is calculated, and the temperature difference b between the primary air powder outlet temperature data and the set first temperature data is calculated; if a>b, c=(a+2b) / 3 is calculated, and if the c is lower than the set first comparison value, the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output, and the value of the first powder collapse operating condition data is positively correlated with the temperature difference b; or, if a is less than or equal to b, c=(2a+b) / 3 is calculated, and if the c is higher than the set second comparison value, the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output, and the value of the first powder collapse operating condition data is positively correlated with the wind speed difference a.

[0025] By adopting the above technical solution, the occurrence or signs of powder collapse can be timely known based on the wind speed or temperature at the powder feeder outlet, which is conducive to timely preventing the deterioration of the powder collapse phenomenon. The change of wind speed data is more sensitive, and the change of temperature data is slower. Therefore, different calculation methods are selected according to different situations, which is conducive to improving the accuracy of the calculation results.

[0026] Optionally, the second calculation method includes the following steps:

[0027] Obtaining the first offset instruction and the first execution time, or the second offset instruction and the second execution time, according to a table lookup calculation;

[0028] Alternatively, the first bias instruction or the second bias instruction is calculated based on the difference between the primary wind powder speed data and the first wind speed data, and the first execution time or the second execution time is calculated based on the change value of the primary wind powder speed data in a set time period;

[0029] Alternatively, the first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data, and the first execution time or the second execution time is calculated based on the change value of the primary air powder outlet temperature data in a set time period.

[0030] By adopting the above technical solution, the bias instruction and execution time are calculated according to the difference in wind speed or temperature, which can prevent the worsening of the powder collapse phenomenon. Once the powder collapse phenomenon is alleviated, the bias instruction will stop executing, and the bias instruction will be adjusted according to the difference in the numerical value, and the execution time will be adjusted according to the change in the numerical value. When the difference change amplitude is small, the change value will be larger. Therefore, based on the situation that the response speed of executing the bias instruction is much lower than the response speed of the continuous execution time, the above method can make the algorithm more adaptable to the hardware situation and improve the control effect.

[0031] Optionally, the second calculation method includes the following steps:

[0032] The first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder velocity data and the first velocity data, and the first execution time or the second execution time is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data;

[0033] or,

[0034] The first execution time instruction or the second execution time is calculated based on the difference between the primary air powder speed data and the first speed data, and the first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data.

[0035] By adopting the above technical solution, during stable operation, the bias instruction is adjusted according to the temperature difference, and the execution time is adjusted according to the wind speed difference. The response speed of executing the bias instruction is lower than the response speed of the continuous execution time, the algorithm is more adapted to the hardware conditions, and the control effect is improved. When the operating data fluctuates, the bias instruction is adjusted according to the wind speed difference, and the execution time is adjusted according to the temperature difference. The strong intervention effect of the bias instruction is enhanced, resulting in a stronger intervention effect. The algorithm is more adapted to the hardware conditions, and the control effect is improved.

[0036] Optionally, a baffle blade and a driving member are provided at the primary air powder outlet, the baffle blade is rotatably connected to the primary air powder outlet of the powder feeder, and the driving member is used to drive the baffle blade to rotate so as to change the powder-facing area of ​​the baffle blade; the resistance value at the baffle blade is positively correlated with the parameter of the first bias instruction;

[0037] Part of the baffle blades includes a plurality of fins arranged along the powder feeding direction, the fins are rotatably connected to the powder feeder, and a rotating shaft is provided at the rotation connection point;

[0038] Part of the baffle blades includes a plurality of fins arranged in series along the powder feeding direction, adjacent fins are rotatably connected, a rotating shaft is provided at the rotation connection point, the end of the rotating shaft is connected to a slide rail, the rotating shaft slides on the slide rail, the length of the baffle blade is inversely correlated with the powder facing area, and the shorter the remaining time of the first execution time is, the longer the length of the baffle blade is;

[0039] The method further includes the following steps: changing the powder-facing area according to the remaining time of the first execution time, wherein the shorter the remaining time of the first execution time is, the smaller the powder-facing area is.

[0040] By adopting the above technical solution, changing the powder receiving area can change the resistance state of the primary air powder outlet, control the powder output of the primary air powder outlet, and help alleviate or eliminate the powder collapse phenomenon.

[0041] Optionally, the method further comprises the following steps: controlling all of the plurality of fin plates to rotate to a set angle from the time of entering the second execution time, and resetting the fin plates in sequence along the powder feeding direction at equal time intervals within the second execution time;

[0042] Alternatively, the length of the baffle blade is controlled to be inversely correlated with the powder facing area, and the shorter the remaining time of the second execution time is, the longer the length of the baffle blade in the powder feeding direction is.

[0043] By adopting the above technical solution, the multiple fins can move in sequence to make the resistance change more continuous and reduce the instability of the system. Changing the length of the baffle blades in the powder feeding direction to adjust the resistance can also intercept a part of the coarser coal powder and play a role in separation.

[0044] On the other hand, the present application provides a control device for the powder collapse condition during the operation of the powder feeder of the central storage type powder making system, which adopts the following technical solution:

[0045] A device for controlling the powder collapse condition of a powder feeder in a central storage type powder making system is based on a controller and an air speed sensor and a temperature sensor provided at the outlet of the powder feeder. The air speed sensor is used to generate primary air-powder speed data, and the temperature sensor is used to generate primary air-powder outlet temperature data. The controller is electrically connected to the air speed sensor and the temperature sensor, and includes the following modules:

[0046] A first acquisition module is configured to acquire operating data of a first powder feeder, wherein the operating data of the first powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data;

[0047] a first calculation module, configured to calculate first powder collapse operating condition data according to a first calculation method based on the first powder feeder operating data, and calculate a first bias instruction and a first execution time according to a second calculation method based on the first powder collapse operating condition data corresponding to the powder collapse phenomenon;

[0048] a first execution module, configured to control the speed of the powder feeder to decrease to a value corresponding to the first bias instruction and to last for a first execution time;

[0049] a first recovery module, configured to control the rotation speed of the powder feeder to return to a state before executing the first bias instruction;

[0050] The controller is electrically connected to a powder discharge control module, and the powder discharge control module includes a baffle blade and a driving member. The baffle blade is rotatably connected to the primary air powder outlet of the powder feeder, and the driving member is used to drive the baffle blade to rotate to change the powder receiving area of ​​the baffle blade; the controller changes the powder receiving area according to the remaining time of the first execution time, and the shorter the remaining time of the first execution time, the smaller the powder receiving area; the resistance value at the baffle blade is positively correlated with the parameters of the first bias instruction.

[0051] By adopting the above technical solution, a bias, namely the first bias instruction, is added to the automatic control loop of the powder feeder speed instruction. The first bias instruction is to reduce the speed of the powder feeder, and the amount of reduction is the bias amount. When signs of powder collapse appear, that is, the primary air powder speed is lower than a set value or the primary air powder outlet temperature is lower than another set value, the powder feeder is controlled to slow down and continue for a first execution time, and then the speed of the powder feeder is restored; the probability of powder collapse in the powder feeder is greatly reduced, and many impending powder collapse phenomena are curbed in the early stages, which greatly reduces the workload of the operating personnel and improves the safety and stability of the unit; changing the powder facing area can change the resistance state of the primary air powder outlet, control the powder output of the primary air powder outlet, and help alleviate or eliminate the powder collapse phenomenon.

[0052] Optionally, the controller further includes the following modules:

[0053] a first persistence module, configured to control the rotation speed of the powder feeder to continue for the first execution time after recovery;

[0054] A second acquisition module is used to acquire operating data of a second powder feeder, wherein the operating data of the second powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data;

[0055] a second calculation module, configured to calculate second powder collapse operating condition data according to a first calculation method based on the second powder feeder operating data, and calculate a second bias instruction and a second execution time according to a second calculation method based on the second powder collapse operating condition data corresponding to the powder collapse phenomenon;

[0056] a second execution module, configured to control the speed of the powder feeder to decrease to a parameter of the second bias instruction and to last for a second execution time;

[0057] a second recovery module, configured to control the rotation speed of the powder feeder to return to a state before executing the first bias instruction;

[0058] a cyclic execution module, configured to cyclically call the first persistence module, the second acquisition module, the second calculation module, the second execution module, and the second recovery module until the latest second powder collapse operating condition data corresponds to no powder collapse;

[0059] Part of the baffle blades includes a plurality of fins arranged along the powder feeding direction, the fins are rotatably connected to the powder feeder, and a rotating shaft is provided at the rotating connection point. From the time of entering the second execution time, all of the plurality of fins are rotated to a set angle, and the fins are reset in sequence along the powder feeding direction at equal time intervals within the second execution time.

[0060] By adopting the above technical solution, after executing the first bias instruction for the first execution time, if there are still signs of powder collapse, after the speed of the powder feeder is restored, the first execution time is delayed, and then the second bias instruction is executed to reduce the speed of the powder feeder for the second execution time, and then the speed is restored, and this process is repeated until the primary air powder speed or the primary air powder outlet temperature reaches the corresponding parameter requirements, and the powder feeder operates normally, and the second bias instruction is no longer executed; the sequential action of multiple fins can make the resistance change more continuous and reduce system instability.

[0061] Optionally, some of the baffle blades include a plurality of fins arranged in series along the powder feeding direction, and the adjacent fins are rotatably connected. A rotating shaft is provided at the rotating connection point, and the end of the rotating shaft is connected to a slide rail. The rotating shaft slides on the slide rail. The length of the baffle blade is inversely correlated with the powder facing area. The shorter the remaining time of the first execution time, the longer the length of the baffle blade.

[0062] By adopting the above technical solution, the resistance can be adjusted by changing the length of the baffle blades in the powder feeding direction, and a portion of the coarser coal powder can be intercepted to play a role in separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a step diagram of a method for controlling a powder collapse condition during operation of a powder feeder in a central storage type powder making system of the present application.

[0064] Figure 2 This is a method for obtaining a second bias instruction and a second execution time in a method for controlling a powder collapse condition during operation of a powder feeder in a central storage type powder making system of the present application.

[0065] Figure 3 This is a step diagram of the first calculation method in the control method of the powder collapse condition during the operation of the powder feeder of a central storage type powder making system in the present application.

[0066] Figure 4 This is a step diagram of the second calculation method in the control method of the powder collapse condition during the operation of the powder feeder of a central storage type powder making system in the present application.

[0067] Figure 5 This is the first structural diagram of the baffle blade and its usage status diagram in the control method of the powder collapse condition during the operation of the powder feeder of the central storage type powder making system of the present application.

[0068] Figure 6 This is a second structural diagram of the baffle blade and its usage status diagram in the control method of the powder collapse condition during the operation of the powder feeder of a central storage type powder making system in the present application.

[0069] Figure 7 This is the third structural diagram of the baffle blades in the control method of the powder collapse condition during the operation of the powder feeder of a central storage type powder making system in the present application.

[0070] Figure 8 This is a third structural diagram of the baffle blade and its usage status diagram in the control method of the powder collapse condition during the operation of the powder feeder of a central storage type powder making system in the present application.

[0071] Figure 9 This is a structural block diagram of a control device for a powder collapse condition during operation of a powder feeder in a central storage type powder making system of the present application.

[0072] Figure 10 This is a structural block diagram of a control device for a powder collapse condition during operation of a powder feeder in a central storage type powder making system of the present application.

[0073] Figure markings: 1. Limit rail; 2. Fin plate; 3. Rotating shaft; 4. Slide rail; 5. Wind speed sensor; 6. Temperature sensor; 7. Controller; 8. First acquisition module; 9. First calculation module; 10. First execution module; 11. First recovery module; 12. Powder output control module; 13. First continuous module; 14. Second acquisition module; 15. Second calculation module; 16. Second execution module; 17. Second recovery module; 18. Loop execution module. DETAILED DESCRIPTION

[0074] Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings.

[0075] Throughout this specification, reference to the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0076] The embodiment of the present application discloses a method for controlling the powder collapse condition during the operation of the powder feeder of the central storage type powder making system, such as Figure 1 As shown, the following steps are included:

[0077] S1: Acquire the operating data of the first powder feeder, wherein the operating data of the first powder feeder includes primary air powder speed data and / or primary air powder outlet temperature data; for example, the primary air powder speed data is 20 m / s; the primary air powder outlet temperature data is 150°C.

[0078] S2: Based on the first powder feeder operation data, first powder collapse operating condition data is calculated according to a first calculation method; based on the first powder collapse operating condition data corresponding to the powder collapse phenomenon, a first bias instruction and a first execution time are calculated according to a second calculation method.

[0079] S3: Control the speed of the powder feeder to reduce to the parameter of the first offset instruction and continue for the first execution time; preferably, in this embodiment, the first offset instruction: the offset amount is -20%; the first execution time is set to 40s.

[0080] S4: Control the rotation speed of the powder feeder to return to the state before executing the first bias instruction.

[0081] An offset command, the first offset command, is added to the automatic control loop for the powder feeder's speed command. This offset command reduces the powder feeder's speed by an offset of -20%. When signs of powder collapse appear, such as the primary air-powder velocity falling below 25m / s or the primary air-powder outlet temperature falling below 156°C, the automatic control loop automatically increases the feeder's speed by a -20% offset for 40 seconds. After 40 seconds, the feeder's speed resumes, and the offset of the first offset command returns to 0. This significantly reduces the probability of powder collapse in the feeder, allowing many impending collapses to be contained in their early stages. This significantly reduces the workload of operators and improves the safety and stability of the thermal power unit.

[0082] like Figure 2 As shown, in the case where the powder collapse phenomenon is more serious, one bias is not enough to solve the powder collapse phenomenon. The method also includes the following steps:

[0083] S5: After the rotation speed of the powder feeder is restored, it is controlled to continue for the first execution time. That is, after the first bias instruction ends, the rotation speed of the powder feeder is restored and continued for 40 seconds.

[0084] S6: Obtain the operating data of the second powder feeder, wherein the operating data of the second powder feeder includes primary air powder speed data and / or primary air powder outlet temperature data; similarly, in this embodiment, preferably, the primary air powder speed data is a primary air powder speed lower than 25 m / s; the primary air powder outlet temperature data is a primary air powder outlet temperature lower than 156°C.

[0085] S7: Based on the second powder feeder operation data, second powder collapse operating condition data is calculated according to the first calculation method; based on the second powder collapse operating condition data corresponding to the powder collapse phenomenon, a second bias instruction and a second execution time are calculated according to the second calculation method.

[0086] S8: Control the speed of the powder feeder to slow down to the parameter of the second offset instruction and continue for the second execution time; preferably, in this embodiment, the second offset instruction: the offset amount is -20%; the second execution time is set to 40s.

[0087] S9: Control the speed of the powder feeder to return to the state before executing the second bias instruction.

[0088] S10: Execute S5-S9 in a loop until the latest second powder collapse working condition data corresponds to no powder collapse.

[0089] For example, if the first offset instruction with a -20% execution offset, obtained by the first calculation method, persists for 40 seconds and signs of powder collapse persist, the feeder will be delayed for another 40 seconds after its speed is restored. Then, based on the second calculation method, a second offset instruction with a -20% execution offset is executed, causing the feeder to slow down for a second execution time of 40 seconds before resuming speed. This process is repeated until the primary air-powder velocity or the primary air-powder outlet temperature meets the corresponding parameter requirements: the primary air-powder velocity is greater than 28 m / s or the primary air velocity is greater than 158°C. Once the feeder is operating normally, the second offset instruction is no longer executed.

[0090] like Figure 3 As shown, the first calculation method has three different calculation methods:

[0091] The first calculation method is based solely on the primary air and powder velocity data. If the first powder feeder operating data includes primary air and powder velocity data, the first feeder operating data is compared with the set first velocity data. If the first feeder operating data is less than the first velocity data, the first powder collapse condition data corresponding to the occurrence of powder collapse is output. The set first velocity data is 28 m / s. For example, if the primary air and powder velocity data is 20 m / s, powder collapse is determined to have occurred.

[0092] The second calculation method is based solely on the primary air powder outlet temperature data. If the primary powder feeder operating data includes primary air powder outlet temperature data, the first powder feeder operating data is compared with a set first temperature data. If the first powder feeder operating data is lower than the first temperature data, the first powder collapse condition data corresponding to the occurrence of powder collapse is output. The set first temperature data is 158°C. For example, if the primary air powder outlet temperature data is 130°C, it is determined that powder collapse has occurred.

[0093] The third calculation method is based on the combination of the primary air powder velocity data and the primary air powder outlet temperature data: if the first powder feeder operation data includes the primary air powder velocity data and the primary air powder outlet temperature data, then the wind speed difference a between the primary air powder velocity data and the set first wind speed data is calculated, and the temperature difference b between the primary air powder outlet temperature data and the set first temperature data is calculated. If a>b, then c=(a+2b) / 3 is calculated, and if c is lower than the set first comparison value, then the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output; the value of the first powder collapse operating condition data is positively correlated with the temperature difference b. Alternatively, if a is less than or equal to b, then c=(2a+b) / 3 is calculated, and if c is higher than the set second comparison value, then the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output; the value of the first powder collapse operating condition data is positively correlated with the wind speed difference a.

[0094] For example, when a = -10 and b = -15, the temperature change is greater than the wind speed change, and the first powder feeding data is lower than the first temperature data, and the first powder feeding data is lower than the first wind speed data, c = (a + 2b) / 3 = -13.33. In this case, powder collapse is determined.

[0095] When a=3, b=1, the temperature fluctuation is smaller than the wind speed fluctuation, the first powder feeding data is greater than the first temperature data, and the first powder feeding data is greater than the first wind speed data, c=(2a+b) / 3=2.33. In this case, it is determined that powder collapse has not occurred.

[0096] When a=0, b=0, the first powder feeding operation data is equal to the first temperature data, and the first powder feeding operation data is equal to the first wind speed data, and c=0, it is determined that the powder collapse phenomenon does not occur.

[0097] Therefore, both the first comparison value and the second comparison value may be 0.

[0098] Based on the three different calculation methods described above, the occurrence or signs of powder collapse can be detected promptly based on the wind speed and / or temperature at the powder feeder outlet, helping to prevent the deterioration of powder collapse. However, wind speed data changes more sensitively, while temperature data changes more slowly. Therefore, choosing different calculation methods based on different situations will help improve the accuracy of the calculation results.

[0099] like Figure 4 As shown, the second calculation method includes the following three methods:

[0100] The first method is table lookup: the first bias instruction and the first execution time, or the second bias instruction and the second execution time, are obtained by table lookup calculation; that is, the values ​​of the first bias instruction, the first execution time, the second bias instruction and the second execution time are all set values ​​and can be obtained by quick table lookup.

[0101] In order to make the algorithm more adaptable to the hardware and improve the control effect, the following methods can also be used:

[0102] The second method is based on the difference and change value calculation between the primary wind powder speed data and the first wind speed data: the first bias instruction or the second bias instruction is obtained according to the difference calculation between the primary wind powder speed data and the first wind speed data, and the first execution time or the second execution time is obtained according to the change value of the primary wind powder speed data in the set time period.

[0103] The third type is calculated based on the difference and change value between the primary air powder outlet temperature data and the first temperature data: the first bias instruction or the second bias instruction is calculated according to the difference between the primary air powder outlet temperature data and the first temperature data, and the first execution time or the second execution time is calculated according to the change value of the primary air powder outlet temperature data in the set time period.

[0104] Calculating the bias instruction and execution time based on the difference in wind speed or temperature can prevent the worsening of the powder collapse phenomenon; and once the powder collapse phenomenon is alleviated, the bias instruction will stop executing; and the bias instruction is adjusted according to the difference in the numerical value, and the execution time is adjusted according to the change in the numerical value; when the difference changes slightly, the change value will be larger; therefore, based on the situation where the response speed of executing the bias instruction is much lower than the response speed of the continuous execution time, the above method can make the algorithm more adaptable to the hardware situation and improve the control effect.

[0105] In addition, the second calculation method can also be set according to different operating conditions. When used, you can adaptively choose to calculate by combining wind speed data and temperature data as follows:

[0106] The fourth method is to calculate the first bias instruction or the second bias instruction according to the difference between the primary air powder speed data and the first wind speed data, and calculate the first execution time or the second execution time according to the difference between the primary air powder outlet temperature data and the first temperature data;

[0107] The fifth type: the first execution time instruction or the second execution time is calculated based on the difference between the primary air powder speed data and the first wind speed data, and the first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data.

[0108] During stable operation, the bias command is adjusted based on temperature differences, and the execution time is adjusted based on wind speed differences. The response speed of executing the bias command is slower than the response speed of executing the continuous execution time, making the algorithm more compatible with the hardware and improving control effectiveness. When operating data fluctuates, the bias command is adjusted based on wind speed differences, and the execution time is adjusted based on temperature differences. This enhances the bias command's strong intervention effect, resulting in a stronger intervention effect. This ensures that the algorithm is more compatible with the hardware and improves control effectiveness.

[0109] In order to further adapt the algorithm to the hardware conditions, the powder receiving area at the primary air powder outlet of the powder feeder is changed, so as to change the resistance state of the primary air powder outlet to control the powder output of the primary air powder outlet, which is more conducive to alleviating or eliminating the powder collapse phenomenon.

[0110] like Figure 5As shown, the primary air powder outlet of the powder feeder is rotatably connected to a baffle blade via a rotating shaft 3. The baffle blade includes a fin, and the rotating shaft 3 is perpendicular to the powder feeder's powder discharge direction. The baffle blade is driven to rotate by a driver, which drives the baffle blade to rotate to change the baffle blade's powder-facing area. When the fin rotates perpendicular to the powder feeder's powder discharge direction, the resistance value at the baffle blade is maximum. The resistance value at the baffle blade is positively correlated with the parameters of the first bias instruction. That is, the greater the resistance value of the baffle blade, the greater the bias of the first bias instruction.

[0111] like Figure 6 As shown, in other embodiments, some of the baffle blades include multiple fins 2 arranged along the powder feeding direction. Each of the fins 2 is rotatably connected to the powder feeder. A rotating shaft 3 is mounted at the rotational connection point between the fins 2 and the powder feeder. The rotating shaft 3 is perpendicular to the powder discharge direction of the powder feeder. Each fin 2 can be driven by a different driving member to change the resistance value at different positions of the baffle blade. The dotted lines represent different angles of the fins 2.

[0112] like Figure 7 and Figure 8 As shown, in other embodiments, some of the baffle blades include a plurality of fins 2 arranged in series along the powder feeding direction, and the sides of adjacent fins 2 are hinged to form a Z-shaped foldable and telescopic structure. A rotating shaft 3 is provided at the hinge, and the rotating shaft 3 is perpendicular to the powder discharge direction of the powder feeder; the ends of the corresponding rotating shafts 3 on the powder feeder are connected with slide rails 4, and the ends of the rotating shafts 3 arranged at intervals slide on the slide rails 4, and the remaining rotating shafts 3 are slidably connected to the movable limit rails 1; the limit rails 1 allow the rotating shaft 3 to slide within the limit rails 1, and the limit rails 1 are linked to the position of the rotating shaft 3 to achieve movement. The driving member is set as an electric cylinder, and the telescopic rod of the electric cylinder is connected to the fin 2 through a connecting rod, thereby driving the baffle blades to change length uniformly as a whole. There are multiple groups of baffle blades, and the gaps between adjacent baffle blades are driven by a driving member. Multiple baffle blades can be synchronously driven by a driving member in combination with a connecting rod; or each baffle blade corresponds to a driving member, and the driving method of the driving member is the same, so that the powder-discharging wind passing through the gaps between the baffle blades passes through a curved and changing path, which is conducive to achieving the separation of gas and large particles while changing the resistance value at the baffle blades. The length of the baffle blade is inversely correlated with the powder-facing area; that is, the longer the baffle blade is, the smaller the powder-facing area is. In addition, in addition to being set horizontally, the powder discharge direction of the powder feeder can also have a certain inclination angle, or even an upward angle, so as to be more conducive to intercepting large particles of coal powder.

[0113] For the baffle blades of the above three structures, the method of changing the powder facing area includes the following steps:

[0114] The powder receiving area is adjusted based on the remaining time of the first execution time. The shorter the remaining time of the first execution time, the longer the baffle blades are, and the smaller the powder receiving area. Changing the powder receiving area can change the resistance state of the primary air powder outlet, control the powder output at the primary air powder outlet, and help alleviate or eliminate powder collapse.

[0115] For the structure of multiple fins 2, the method for changing the powder facing area also includes the following steps: from entering the second execution time, all the fins 2 are controlled to rotate to the set angle, and the fins 2 are reset in sequence at equal time intervals along the powder feeding direction within the second execution time.

[0116] Alternatively, the length of the baffle blades is controlled to be inversely correlated with the powder facing area, and the shorter the remaining time of the second execution time is, the longer the length of the baffle blades in the powder feeding direction is.

[0117] For the third structure of the baffle blades, the sequential movement of multiple fins 2 can make the resistance change more continuous, reduce the instability of the system, and change the length of the baffle blades in the powder feeding direction to adjust the resistance. The wind that feeds the powder to the powder feeder passes through the interaction between multiple baffle blades. The distance between two adjacent baffle blades becomes larger or smaller according to the set driving mode, so that the coarser coal powder is intercepted, which plays a role of separation.

[0118] This embodiment also discloses a control device for the powder collapse condition during the operation of the powder feeder of the central storage type powder making system, such as Figure 9 As shown, based on the controller 7 and the wind speed sensor 5 and temperature sensor 6 arranged at the outlet of the powder feeder, the wind speed sensor 5 is used to generate primary wind-powder speed data, and the temperature sensor 6 is used to generate primary wind-powder outlet temperature data; the controller 7 is electrically connected to the wind speed sensor 5 and the temperature sensor 6, and the controller 7 includes the following modules: a first acquisition module 8, a first calculation module 9, a first execution module 10, a first recovery module 11 and a powder output control module 12.

[0119] A first acquisition module 8 is used to acquire the operating data of the first powder feeder, wherein the operating data of the first powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data;

[0120] A first calculation module 9 is configured to calculate first powder collapse operating condition data based on the first powder feeder operating data according to a first calculation method, and to calculate a first bias instruction and a first execution time based on the first powder collapse operating condition data corresponding to the powder collapse phenomenon according to a second calculation method;

[0121] A first execution module 10 is used to control the speed of the powder feeder to decrease to a parameter of a first bias instruction and to last for a first execution time;

[0122] A first recovery module 11 is used to control the speed of the powder feeder to return to the state before executing the first bias instruction;

[0123] The controller 7 is electrically connected to a powder output control module 12, which includes a baffle blade and a drive member. The baffle blade is rotatably connected to the primary air powder outlet of the powder feeder, and the baffle blade is driven to rotate by the drive member; the drive member drives the baffle blade to rotate to change the powder receiving area of ​​the baffle blade. The resistance value at the baffle blade is positively correlated with the parameters of the first bias instruction, that is, the greater the resistance value of the baffle blade, the greater the bias amount of the first bias instruction. The controller 7 changes the powder receiving area according to the remaining time of the first execution time. The shorter the remaining time of the first execution time, the smaller the powder receiving area; the resistance value at the baffle blade is positively correlated with the parameters of the first bias instruction.

[0124] Add an offset to the automatic control loop of the powder feeder speed command, namely the first offset command. The first offset command is to reduce the speed of the powder feeder, for example, the reduction amount is the offset amount -20%. When signs of powder collapse appear, it can be set so that the primary air powder speed is lower than 25m / s and / or the primary air powder outlet temperature is lower than 156℃. When the powder feeder is automatic, the powder feeder is controlled to automatically increase a -20% offset and maintain the first execution time, for example, 40 seconds. After 40 seconds, the speed of the powder feeder is restored, that is, the offset amount of the first offset command is restored to 0. The probability of powder collapse in the powder feeder is greatly reduced, and many impending powder collapse phenomena are curbed in the early stages, which greatly reduces the workload of operators and improves the safety and stability of the thermal power unit.

[0125] like Figure 10 As shown, the controller 7 further includes the following modules: a first persistence module 13 , a second acquisition module 14 , a second calculation module 15 , a second execution module 16 , a second recovery module 17 and a loop execution module 18 .

[0126] The first continuing module 13 is used to control the rotation speed of the powder feeder to continue for a first execution time after recovery.

[0127] The second acquisition module 14 is configured to acquire operating data of the second powder feeder, wherein the operating data of the second powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data.

[0128] The second calculation module 15 is used to calculate the second powder collapse condition data based on the second powder feeder operation data according to the first calculation method, and calculate the second bias instruction and the second execution time based on the second powder collapse condition data corresponding to the powder collapse phenomenon according to the second calculation method.

[0129] The second execution module 16 is configured to control the speed of the powder feeder to decrease to a parameter of a second bias instruction and to continue for a second execution time.

[0130] The second recovery module 17 is used to control the rotation speed of the powder feeder to return to the state before executing the first bias instruction.

[0131] The loop execution module 18 is used to loop call the first persistence module 13, the second acquisition module 14, the second calculation module 15, the second execution module 16 and the second recovery module 17 until the latest second powder collapse condition data corresponds to no powder collapse.

[0132] In other embodiments, some of the baffle blades include multiple fins 2 arranged along the powder feeding direction. Each of the fins 2 is rotatably connected to the powder feeder, and a rotating shaft 3 is mounted at the rotational connection point between the fins 2 and the powder feeder, with the rotating shaft 3 being perpendicular to the powder discharge direction of the powder feeder. Each fin 2 can be driven by a different drive member to change the resistance value at different positions of the baffle blades. Upon entering the second execution time, all of the multiple fins 2 are rotated to a set angle and reset sequentially along the powder feeding direction at equal intervals during the second execution time.

[0133] After executing the first bias instruction for the first execution time, if there are still signs of powder collapse, the first execution time will be delayed after the speed of the powder feeder is restored, and then the second bias instruction will be executed to slow down the powder feeder and continue for the second execution time, such as 40 seconds, and then the speed will be restored. This process is repeated until the primary air powder speed or the primary air powder outlet temperature reaches the corresponding parameter requirements. After the powder feeder operates normally, the second bias instruction will no longer be executed; the sequential action of multiple fins 2 can make the resistance change more continuous and reduce system instability.

[0134] In other embodiments, some baffle blades include multiple fins 2 arranged in series along the powder feeding direction. Adjacent fins 2 are hinged on their sides to form a Z-shaped, foldable, and retractable structure. A rotating shaft 3 is provided at the hinge, perpendicular to the powder discharge direction of the powder feeder. Slide rails 4 are connected to the corresponding ends of the rotating shafts 3 on the powder feeder. Intervals between the ends of the rotating shafts 3 slide on the slide rails 4, while the remaining rotating shafts 3 slide on movable limit rails 1. The limit rails 1 allow the rotating shafts 3 to slide within the limit rails 1, and the limit rails 1 move in tandem with the position of the rotating shafts 3, enabling movement. The drive element is configured as an electric cylinder, whose telescopic rod is connected to the fins 2 via a connecting rod, thereby driving the baffle blades to uniformly change length. The length of the baffle blades is inversely correlated with the powder feeding area; that is, the longer the baffle blades, the smaller the powder feeding area. The baffle blade length is controlled to be inversely correlated with the powder feeding area. The shorter the remaining time of the second execution time, the longer the baffle blades in the powder feeding direction.

[0135] The resistance is adjusted by changing the length of the baffle blades in the powder feeding direction. The sequential movement of multiple fins 2 can make the resistance change more continuous, reduce the instability of the system, and adjust the resistance by changing the length of the baffle blades in the powder feeding direction. It can also intercept a part of the coarser coal powder and play a role in separation.

[0136] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for controlling the powder collapse condition during operation of a powder feeder in a central storage type powder making system, characterized in that: The steps include: S1: Acquire operating data of a first powder feeder, wherein the operating data of the first powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data; S2: Calculating first powder collapse condition data according to a first calculation method based on the first powder feeder operation data; calculating a first bias instruction and a first execution time according to a second calculation method based on the first powder collapse condition data corresponding to the powder collapse phenomenon; S3: controlling the speed of the powder feeder to decrease to a parameter of the first bias instruction and continuing for the first execution time; S4: controlling the rotation speed of the powder feeder to return to the state before executing the first bias instruction; If the first powder feeder operation data includes primary air powder speed data and primary air powder outlet temperature data, then the wind speed difference a between the primary air powder speed data and the set first wind speed data is calculated, and the temperature difference b between the primary air powder outlet temperature data and the set first temperature data is calculated; if a>b, then c=(a+2b) / 3 is calculated, and if the c is lower than the set first comparison value, then the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output, and the value of the first powder collapse operating condition data is positively correlated with the temperature difference b; or, if a is less than or equal to b, then c=(2a+b) / 3 is calculated, and if the c is higher than the set second comparison value, then the first powder collapse operating condition data corresponding to the powder collapse phenomenon is output, and the value of the first powder collapse operating condition data is positively correlated with the wind speed difference a.

2. The method according to claim 1, characterized in that The method further comprises the steps of: S5: controlling the speed of the powder feeder to continue for the first execution time after recovery; S6: Acquire operating data of the second powder feeder, wherein the operating data of the second powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data; S7: Calculating second powder collapse operating condition data according to the first calculation method based on the second powder feeder operating data; calculating a second bias instruction and a second execution time according to the second calculation method based on the second powder collapse operating condition data corresponding to the powder collapse phenomenon; S8: controlling the speed of the powder feeder to decrease to a parameter of the second bias instruction and continuing for the second execution time; S9: controlling the speed of the powder feeder to return to the state before executing the second bias instruction; S10: Execute S5-S9 in a loop until the latest second powder collapse working condition data corresponds to no powder collapse.

3. The method according to claim 2, characterized in that The second calculation method comprises the following steps: Obtaining the first offset instruction and the first execution time, or the second offset instruction and the second execution time, according to a table lookup calculation; Alternatively, the first bias instruction or the second bias instruction is calculated based on the difference between the primary wind powder speed data and the first wind speed data, and the first execution time or the second execution time is calculated based on the change value of the primary wind powder speed data in a set time period; Alternatively, the first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data, and the first execution time or the second execution time is calculated based on the change value of the primary air powder outlet temperature data in a set time period.

4. The method according to claim 2, characterized in that The second calculation method comprises the following steps: The first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder velocity data and the first velocity data, and the first execution time or the second execution time is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data; or, The first execution time instruction or the second execution time is calculated based on the difference between the primary air powder speed data and the first speed data, and the first bias instruction or the second bias instruction is calculated based on the difference between the primary air powder outlet temperature data and the first temperature data.

5. The method according to claim 2, characterized in that The primary air powder outlet is provided with a baffle blade and a driving member, the baffle blade is rotatably connected to the primary air powder outlet of the powder feeder, and the driving member is used to drive the baffle blade to rotate so as to change the powder-facing area of ​​the baffle blade; the resistance value at the baffle blade is positively correlated with the parameter of the first bias instruction; Part of the baffle blades comprises a plurality of fins (2) arranged along the powder feeding direction, the fins (2) are rotatably connected to the powder feeder, and a rotating shaft (3) is provided at the rotation connection point; Part of the baffle blades includes a plurality of fins (2) arranged in series along the powder feeding direction, adjacent fins (2) are rotatably connected, a rotating shaft (3) is provided at the rotation connection point, an end of the rotating shaft (3) is connected to a slide rail (4), and the rotating shaft (3) slides on the slide rail (4), and the length of the baffle blade is inversely correlated with the powder receiving area. The shorter the first execution time, the longer the length of the baffle blade; The method further includes the following steps: changing the powder-facing area according to the remaining time of the first execution time, wherein the shorter the remaining time of the first execution time is, the smaller the powder-facing area is.

6. The method according to claim 5, characterized in that The method further comprises the following steps: controlling all of the plurality of fin plates (2) to rotate to a set angle from the time of entering the second execution time, and resetting the fin plates (2) in sequence at equal time intervals along the powder feeding direction within the second execution time; Alternatively, the length of the baffle blade is controlled to be inversely correlated with the powder facing area, and the shorter the remaining time of the second execution time is, the longer the length of the baffle blade in the powder feeding direction is.

7. A control device for the powder collapse condition during the operation of a powder feeder in a central storage type powder making system, characterized in that: Based on a controller (7) and an air speed sensor (5) and a temperature sensor (6) provided at the powder feeder outlet, the air speed sensor (5) is used to generate primary air-powder air speed data, and the temperature sensor (6) is used to generate primary air-powder outlet temperature data; the controller (7) is electrically connected to the air speed sensor (5) and the temperature sensor (6), and the controller (7) includes the following modules: a first acquisition module (8) for acquiring operating data of a first powder feeder, wherein the operating data of the first powder feeder includes primary air-powder velocity data and / or primary air-powder outlet temperature data; a first calculation module (9) for calculating first powder collapse operating condition data according to a first calculation method based on the first powder feeder operation data, and calculating a first bias instruction and a first execution time according to a second calculation method based on the first powder collapse operating condition data corresponding to the powder collapse phenomenon; if the first powder feeder operation data includes primary air powder velocity data and primary air powder outlet temperature data, then calculating a wind speed difference a between the primary air powder velocity data and a set first wind speed data, and calculating a temperature difference b between the primary air powder outlet temperature data and a set first temperature data; if a>b, then calculating c=(a+2b) / 3, and if c is lower than a set first comparison value, then outputting the first powder collapse operating condition data corresponding to the powder collapse phenomenon, the value of the first powder collapse operating condition data being positively correlated with the temperature difference b; or, if a is less than or equal to b, then calculating c=(2a+b) / 3, and if c is higher than a set second comparison value, then outputting the first powder collapse operating condition data corresponding to the powder collapse phenomenon, the value of the first powder collapse operating condition data being positively correlated with the wind speed difference a; a first execution module (10), configured to control the speed of the powder feeder to decrease to a value corresponding to the first bias instruction and to last for the first execution time; a first recovery module (11), configured to control the rotation speed of the powder feeder to return to a state before executing the first bias instruction; The controller (7) is electrically connected to a powder discharge control module (12), and the powder discharge control module (12) includes a baffle blade and a driving member, wherein the baffle blade is rotatably connected to the primary air powder outlet of the powder feeder, and the driving member is used to drive the baffle blade to rotate so as to change the powder receiving area of ​​the baffle blade; the controller (7) changes the powder receiving area according to the remaining time of the first execution time, and the shorter the remaining time of the first execution time, the smaller the powder receiving area; the resistance value at the baffle blade is positively correlated with the parameter of the first bias instruction.

8. The device according to claim 7, characterized in that The controller (7) further comprises the following modules: A first persistence module (13) is used to control the rotation speed of the powder feeder to continue for the first execution time after recovery; A second acquisition module (14) is used to acquire operating data of a second powder feeder, wherein the operating data of the second powder feeder includes primary air-powder velocity data and primary air-powder outlet temperature data; A second calculation module (15) is configured to calculate second powder collapse operating condition data based on the second powder feeder operating data according to a first calculation method, and to calculate a second bias instruction and a second execution time based on the second powder collapse operating condition data corresponding to the occurrence of the powder collapse phenomenon according to a second calculation method; a second execution module (16), configured to control the speed of the powder feeder to decrease to a value corresponding to the second bias instruction and to last for a second execution time; a second recovery module (17), configured to control the rotation speed of the powder feeder to return to a state before executing the first bias instruction; a cyclic execution module (18) for cyclically calling the first persistence module (13), the second acquisition module (14), the second calculation module (15), the second execution module (16) and the second recovery module (17) until the latest second powder collapse working condition data corresponds to no powder collapse; Part of the baffle blades includes a plurality of fins (2) arranged along the powder feeding direction, the fins (2) are rotatably connected to the powder feeder, and a rotating shaft (3) is provided at the rotation connection point. The plurality of fins (2) are rotated to a set angle from the time of entering the second execution time, and the fins (2) are reset in sequence along the powder feeding direction at equal time intervals within the second execution time.

9. The device according to claim 7, characterized in that Part of the baffle blades includes a plurality of fins (2) arranged in series along the powder feeding direction, adjacent fins (2) are rotatably connected, a rotating shaft (3) is provided at the rotating connection point, the end of the rotating shaft (3) is connected to a slide rail (4), and the rotating shaft (3) slides on the slide rail (4). The length of the baffle blade is inversely correlated with the powder receiving area. The shorter the remaining time of the first execution time, the longer the length of the baffle blade.

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