Method, device, medium, equipment and program product for controlling primary air volume of coal mill

Abstract

The present disclosure relates to a coal mill primary air volume control method, device, medium, equipment and program product, and relates to the field of coal mill control; including: determining a first instruction of a primary air speed of a coal mill according to the primary air speed of each outlet of a plurality of outlets of the coal mill; determining a second instruction of the primary air speed of the coal mill according to a coal feeding instruction of a coal feeder; determining a primary air control instruction of the coal mill according to the first instruction of the primary air speed and / or the second instruction of the primary air speed; and adjusting a hot air damper opening degree of the coal mill according to the primary air control instruction to control a primary air volume at an inlet of the coal mill. By adjusting the primary air volume at the inlet of the coal mill according to the primary air speed at the outlet of the coal mill, the primary air volume of the coal mill and the load synchronization of the coal mill can be better maintained, thereby reducing the possibility of failure during the operation of the coal mill.

Description

Technical Field

[0001] This disclosure pertains to the field of coal mill control, specifically to methods, devices, media, equipment, and program products for controlling the primary air volume of coal mills. Background Technology

[0002] Controlling the primary air volume of a coal mill requires ensuring both rapid response of pulverized coal to load changes and safe operation of the mill. Insufficient primary air volume may lead to mill stagnation, burnout of the burners, or spontaneous combustion of pulverized coal deposits in certain areas; excessive primary air volume increases exhaust gas temperature, reduces boiler efficiency, and increases wear on the primary air duct and power consumption of the primary air fan. Therefore, the control of the primary air volume must be synchronized with the load in real time to ensure economical and safe boiler operation. However, in many power plants, the primary air volume measurement points for coal mills are often inaccurate due to limited space in the mill inlet duct, improper installation location, and easy blockage of the measurement points themselves. Furthermore, since the actual primary air volume measured is the air volume at the mill inlet, it also includes the sealing air from the mill and feeder. This air volume changes with the mill's operating conditions, making it impossible for the measurement points to accurately reflect the actual primary air volume inside the mill. This leads to a mismatch between the primary air volume and the load, increasing the likelihood of mechanical failures during mill operation. Summary of the Invention

[0003] To overcome the problems existing in the related technologies, this disclosure provides a method, device, medium, equipment and program product for controlling the primary air volume of a coal mill.

[0004] According to a first aspect of the present disclosure, a method for controlling the primary air volume of a coal mill is provided, comprising: The primary air velocity of the coal mill is determined based on the primary air velocity at each of the multiple outlets of the coal mill. The primary air speed of the coal mill is determined according to the coal feeding command of the coal feeder; The primary air control command of the coal mill is determined according to the first primary air speed command and / or the second primary air speed command; The opening of the hot air damper of the coal mill is adjusted according to the primary air control command to control the primary air volume at the coal mill inlet.

[0005] Optionally, determining the second command for the primary air speed of the coal mill based on the coal feeder's feeding command includes: The primary air speed second command is determined based on the coal feeding type and coal feeding rate of the coal mill; the coal feeding command includes the coal feeding type and coal feeding rate.

[0006] Optionally, after determining the second command for the primary air velocity of the coal mill based on the coal feeder's feeding command, the method further includes: Obtain the manually input wind speed correction command from the coal mill; The primary wind speed second command is modified according to the wind speed correction command.

[0007] Optionally, determining the primary air control command for the coal mill based on the first primary air speed command and / or the second primary air speed command includes: Determine the deviation between the first primary wind speed command and the second primary wind speed command; The primary air control command is determined based on the coal feeding command and the deviation value.

[0008] Optionally, the method further includes: When the primary air velocity at the first outlet of the coal mill is less than the air velocity threshold, the primary air control command is corrected according to the primary air velocity; the first outlet is any one of the multiple outlets of the coal mill.

[0009] Optionally, the method further includes: Determine whether the coal mill meets the condition of correcting the primary air control command according to the cold air damper; If the conditions are met, the primary air control command is modified according to the cold air damper of the coal mill.

[0010] Optionally, the conditions for correcting the primary air control command based on the cold air damper include: The cold air damper and hot air damper of the coal mill are in automatic control mode; The cold air damper correction function of the coal mill is in operation mode; The cold air control valve's cold air control valve command value is greater than the cold air control valve correction value; The average primary wind speed at the multiple outlets of the coal mill is greater than or equal to the first wind speed threshold. The primary wind speed at any of the multiple outlets of the coal mill is greater than the second wind speed threshold.

[0011] Optionally, the step of correcting the primary air control command according to the cold air damper of the coal mill when the conditions are met includes: Determine the deviation between the cold air control valve command value and the cold air control valve correction value of the coal mill cold air control valve; The primary air control command is corrected based on the deviation value.

[0012] Optionally, the method further includes: The correction of the primary air control command based on the cold air damper shall cease when any one of the following conditions is met: The cold air damper and hot air damper of the coal mill are in manual control mode; The cold air damper correction function of the coal mill is in the off mode; The cold air damper command value is less than or equal to the cold air damper correction value; The average primary wind speed at the multiple outlets of the coal mill is less than the first wind speed threshold. The primary wind speed at any of the multiple outlets of the coal mill is less than or equal to the second wind speed threshold. The change in the average primary wind speed at the multiple outlets of the coal mill is greater than or equal to the third wind speed threshold.

[0013] According to a second aspect of the present disclosure, a primary air volume control device for a coal mill is provided, comprising: The first determining module is used to determine the primary air velocity first command of the coal mill based on the primary air velocity of each of the multiple outlets of the coal mill; The second determining module is used to determine the primary air speed second command of the coal mill based on the coal feeding command of the coal feeder; The third determining module is used to determine the primary air control command of the coal mill based on the first primary air speed command and / or the second primary air speed command. The control module is used to adjust the opening of the hot air damper of the coal mill according to the primary air control command, so as to control the primary air volume at the inlet of the coal mill.

[0014] According to a third aspect of the present disclosure, a computer-readable storage medium is provided, having stored thereon computer program instructions that, when executed by a processor, implement the steps of the coal mill primary air volume control method provided in the first aspect of the present disclosure.

[0015] According to a fourth aspect of the present disclosure, an electronic device is provided, comprising: A memory on which computer programs are stored; A processor is configured to execute the computer program in the memory to implement the steps of the coal mill primary air volume control method provided in the first aspect of this disclosure.

[0016] According to a fifth aspect of the present disclosure, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the coal mill primary air volume control method provided in the first aspect of the present disclosure.

[0017] The above technical solution determines the primary air velocity command of the coal mill based on the primary air velocity at each of its multiple outlets; it also determines the primary air velocity command based on the coal feeder's feeding command; and finally, it determines the primary air control command based on the first and / or second primary air velocity commands. The opening of the hot air damper of the coal mill is then adjusted according to the primary air control command to control the primary air volume at the coal mill inlet. By adjusting the primary air volume at the coal mill inlet using the primary air velocity at the coal mill outlet, the synchronization between the primary air volume and the coal mill load can be better maintained, thereby reducing the possibility of malfunctions during coal mill operation.

[0018] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0020] Figure 2 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0021] Figure 3 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0022] Figure 4 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0023] Figure 5 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0024] Figure 6 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0025] Figure 7 This is a flowchart illustrating a method for controlling the primary air volume of a coal mill according to an exemplary embodiment.

[0026] Figure 8 This is a schematic diagram of a primary air volume control device 800 for a coal mill, according to an exemplary embodiment.

[0027] Figure 9 This is a schematic diagram of an electronic device 900 according to an exemplary embodiment. Detailed Implementation

[0028] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0029] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0030] Figure 1 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 1 As shown, the method includes the following steps: In step S101, the primary air velocity first command of the coal mill is determined based on the primary air velocity of each of the multiple outlets of the coal mill.

[0031] For example, the main function of a coal mill is to grind raw coal into pulverized coal that meets combustion requirements. During the operation of the coal mill, pulverized coal is prepared through the grinding and separation action of the mill and then transported to the subsequent combustion system or storage facilities through the mill outlet. The control of the primary air at the coal mill inlet is crucial for ensuring the boiler combustion efficiency and the safe operation of the coal mill itself. The primary air transports the pulverized coal from the mill to the furnace and also dries it to ensure combustion. Furthermore, the control of the primary air at the coal mill inlet affects the temperature of the air-coal mixture at the mill outlet, as well as the primary air at the mill outlet, thus affecting combustion efficiency and the safety of the coal mill. Therefore, the primary air at the coal mill inlet and the primary air at the coal mill outlet are closely related, and the primary air at the coal mill inlet can be dynamically adjusted based on the primary air at the coal mill outlet.

[0032] The coal mill has multiple outlets, each equipped with a wind speed measuring device to measure the primary wind speed at each outlet. Based on the primary wind speed at each outlet, a first primary wind speed command for the coal mill can be determined. This first primary wind speed command refers to the control command for the primary air at the coal mill inlet, determined based on the primary wind speed at the coal mill outlet. At this time, the hot air damper of the coal mill can be controlled according to this first primary wind speed command to control the primary air at the coal mill inlet.

[0033] Taking a 330MW coal-fired boiler direct-fired pulverizing system as an example, if the pulverizer in this system has four outlets, the primary wind speed at the pulverizer inlet can be determined based on the primary wind speed at each of the four outlets. For example, at each of the four outlets of the pulverizer, after filtering for 5 seconds, the primary wind speed corresponding to that outlet can be obtained. After determining the primary wind speed corresponding to the four outlets, the average value of the primary wind speed corresponding to the four outlets can be multiplied by a specified coefficient to obtain the primary wind speed first command. Filtering can remove instantaneous fluctuations and noise in the wind speed readings caused by turbulence in the airflow inside the duct or external environmental factors, ensuring a more stable primary wind speed measurement value, reducing measurement errors caused by sudden changes in wind speed, and thus improving the reliability and stability of the data.

[0034] Furthermore, step S101 may include the following steps: Obtain the primary air velocity at each of the multiple outlets of the coal mill to obtain multiple primary air velocities; The data processing is performed on the multiple primary wind speeds to filter out outliers. The first command for the primary wind speed is determined based on the average of multiple primary wind speeds after data processing.

[0035] In step S102, the second command for the primary air speed of the coal mill is determined according to the coal feeding command of the coal feeder.

[0036] For example, the primary air in a coal mill is used to dry pulverized coal and transport it from the mill to the furnace. Therefore, a second primary air velocity command at the mill inlet can be determined based on the coal feeding command of the coal mill. The coal feeding command may include the coal feed rate and / or coal feed type. For instance, the coal feeding command of the coal feeder can be converted into a corresponding second primary air velocity command via a function.

[0037] In step S103, the primary air control command of the coal mill is determined according to the first primary air speed command and / or the second primary air speed command.

[0038] For example, if the primary air volume at the inlet of the coal mill is too low, it may cause pulverization blockage in the primary air duct or coal blockage in the coal mill, or even cause an explosion in the pulverizing system; while if the primary air volume of the coal mill is too high, it may increase the energy consumption of the primary air fan and reduce the efficiency of the boiler. Therefore, the primary air control of the coal mill is crucial to the safe operation of the coal mill. Furthermore, the primary air control of a coal mill is a dynamic process, and the primary air volume may be affected by one or more factors. Changes in the primary air velocity at the mill inlet and outlet determine the internal working state, grinding conditions, and coal quantity changes within the mill. Therefore, the primary air at the mill inlet can be controlled based on the primary air velocity at the mill outlet, i.e., the primary air control command for the mill can be determined based on the primary air velocity first command. Alternatively, the primary air at the mill inlet can be controlled based on changes in the coal quantity within the mill, i.e., the primary air control command for the mill can be determined based on the primary air velocity second command. Or, the primary air at the mill inlet can be controlled based on both the primary air velocity at the mill outlet and changes in the coal quantity within the mill, i.e., the primary air control command for the mill can be determined based on the primary air velocity first command and the primary air velocity second command. For example, the primary air control command can be determined based on the average value of the primary air velocity first command and the primary air velocity second command; or, the primary air control command can be determined based on the maximum value of the primary air velocity first command and the primary air velocity second command.

[0039] In step S104, the opening of the hot air damper of the coal mill is adjusted according to the primary air control command to control the primary air volume at the inlet of the coal mill.

[0040] For example, the primary air control of the coal mill mainly relies on the opening adjustment of the hot air damper. The hot air damper controls the temperature and volume of the primary air by adjusting the proportion of hot air entering the coal mill. Specifically, adjusting the opening of the hot air damper via the primary air control command can be automatically adjusted by control logic. When the measured value of the primary air volume at the coal mill inlet is greater than the set value in the primary air control command, it indicates that the hot air proportion is too high or the total primary air volume is too large. In this case, the opening of the hot air damper can be reduced to decrease the hot air proportion and primary air volume. Conversely, when the measured value of the primary air volume at the coal mill inlet is less than the set value in the primary air control command, it indicates that the hot air proportion is too low or the total primary air volume is too small. In this case, the opening of the hot air damper can be increased to increase the hot air proportion and primary air volume.

[0041] The above technical solution determines the primary air velocity command of the coal mill based on the primary air velocity at each of its multiple outlets; it also determines the primary air velocity command based on the coal feeder's feeding command; and finally, it determines the primary air control command based on the primary air velocity command and / or the primary air velocity command. The opening of the hot air damper of the coal mill is adjusted according to the primary air control command to control the primary air volume at the coal mill inlet. By adjusting the primary air volume at the coal mill inlet using the primary air velocity at the coal mill outlet, the synchronization between the primary air volume and the coal mill load can be better maintained, thereby reducing the possibility of malfunctions during coal mill operation.

[0042] Figure 2 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 2 As shown, step S102 includes the following steps: In step S1021, the second primary air speed command is determined according to the coal feeding type and coal feeding rate of the coal mill; the coal feeding command includes the coal feeding type and coal feeding rate.

[0043] For example, the inlet and outlet of a coal mill can be considered as an isenthalpic change process (no heat generation, no work done), and the heat loss is approximately equal to the heat loss from mechanical work, which is very small and can be ignored. Therefore, it can be considered that the total heat at the coal mill inlet = the total heat at the coal mill outlet, that is, the heat of the coal at the coal mill inlet + the heat of the air at the coal mill inlet = the heat of the pulverized coal at the coal mill outlet + the heat of the air at the coal mill outlet; Wherein, the heat of coal at the pulverizer inlet = the heat of other components in the coal at the pulverizer inlet + the heat of water at the pulverizer inlet; Heat of water at the inlet of the coal mill = Enthalpy of water at the inlet of the coal mill × Moisture content of coal at the inlet of the coal mill; Moisture content of coal at the pulverizer inlet = Coal feed rate × Moisture content; Heat of pulverized coal at the coal mill outlet = Heat of other components of coal at the coal mill outlet + Heat of water in the coal at the coal mill outlet.

[0044] In summary, with the same coal feed rate, the higher the moisture content of the coal, the greater the required primary air volume. Therefore, coal types can be classified according to their moisture content. Furthermore, based on the aforementioned enthalpy change process, the coal feed rate and coal type at the pulverizer inlet will affect the primary air volume at the pulverizer inlet. Therefore, the second command for the primary air velocity can be determined based on the coal feed rate and coal type at the pulverizer inlet.

[0045] Figure 3 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 3 As shown, after step S102, the method further includes the following steps: In step S105, the manually input wind speed correction command in the coal mill is obtained.

[0046] In step S106, the primary wind speed second command is corrected according to the wind speed correction command.

[0047] For example, while determining the second primary air speed command for the coal mill based on the coal feeder's feeding instruction, the coal mill operator can modify this second primary air speed command according to the actual situation. Therefore, when a manually input air speed correction command is received, the second primary air speed command can be modified according to that command. For instance, the air speed correction command and the second primary air speed command can be fed together into an adder, and after calculation, the modified command can be used as the second primary air speed command.

[0048] Figure 4 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 4 As shown, step S103 includes the following steps: In step S1031, the deviation value between the first primary wind speed command and the second primary wind speed command is determined.

[0049] In step S1032, the primary air control command is determined based on the coal feeding command and the deviation value.

[0050] For example, the coal feeding command can change with the amount of coal inside the coal mill; therefore, the coal feeding command can be used as a feedforward signal, and the primary air control command can be determined based on the first primary air speed command and the second primary air speed command; for example, the deviation value between the first primary air speed command and the second primary air speed command can be determined, and then the primary air control command can be determined based on the coal feeding command and the deviation value.

[0051] Figure 5 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 5 As shown, the method also includes the following steps: In step S107, when the primary air velocity at the first outlet of the coal mill is less than the air velocity threshold, the primary air control command is corrected according to the primary air velocity; the first outlet is any one of the multiple outlets of the coal mill.

[0052] For example, during the coal grinding process, a coal mill requires primary air to ensure the fineness of the pulverized coal, its dryness, and its conveying and combustion. If the primary air volume and / or velocity of the coal mill is too low, the following problems may occur: coal dust may accumulate inside the coal mill or in the conveying pipes, causing coal blockage; the air velocity in the coal mill's air ring may decrease, resulting in insufficient fineness of the pulverized coal; incomplete combustion of the pulverized coal; and the pulverized coal may not be completely dried. Therefore, a velocity threshold can be set. When the primary air velocity at the first outlet of the coal mill is less than the threshold, the primary air control command is corrected based on the primary air velocity at the first outlet. For example, if the velocity threshold is 18 m / s, when the primary air velocity at the first outlet is less than 18 m / s, the primary air velocity in the primary air control command is increased at a specified rate until the primary air velocity at the first outlet is greater than or equal to 18 m / s. This specified rate can be determined based on the magnitude of the primary air velocity at the first outlet; that is, different specified rates correspond to different ranges of primary air velocity at the first outlet. Furthermore, to prevent the primary wind speed at the first outlet from continuously decreasing, the method can also set an alarm threshold. If the alarm threshold is greater than the wind speed threshold, and the primary wind speed at the first outlet equals the alarm threshold, then an interlock is executed (the primary wind speed in the primary wind control command no longer decreases), and a low primary wind speed alarm is issued. Here, the first outlet can be any one of the multiple outlets of the coal mill.

[0053] In another possible embodiment, the method further includes: When the average primary air velocity at multiple outlets of the coal mill is less than the air velocity threshold, the primary air control command is corrected based on the average primary air velocity.

[0054] Figure 6 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 6 As shown, the method also includes the following steps: In step S108, it is determined whether the coal mill meets the condition of correcting the primary air control command according to the cold air damper.

[0055] In step S109, if the condition is met, the primary air control command is modified according to the cold air damper of the coal mill.

[0056] For example, during the operation of a coal mill, the cold air damper is used to control the mill outlet temperature. A large opening of the cold air damper indicates excessive drying output. While ensuring adequate ventilation output, the primary air velocity at the mill inlet can be appropriately reduced, thereby automatically closing the cold air damper and lowering the exhaust gas temperature. Therefore, when the operating conditions of the coal mill meet the requirements for correcting the primary air control command based on the cold air damper, the primary air control command can be corrected accordingly.

[0057] Optionally, the conditions for modifying the primary air control command based on the cooling air damper include: The cold air damper and hot air damper of the coal mill are in automatic control mode; The cold air regulating damper correction function of the coal mill is in operation mode; The cold air damper's command value is greater than its correction value. The average primary air velocity at multiple outlets of the coal mill is greater than or equal to the first air velocity threshold. The primary wind speed at any of the multiple outlets of the coal mill is greater than the second wind speed threshold.

[0058] The coal mill's cold air damper and hot air damper both include automatic and manual control modes. In automatic control mode, the primary air control command can be corrected based on the cold air damper. The coal mill includes a function to correct the primary air control command based on the cold air damper. When this function is in operation, the primary air control command can be corrected based on the cold air damper. The correction value for the cold air damper is a manually set minimum cold air value. Correction of the primary air control command based on the cold air damper is only necessary when the cold air damper command value generated in automatic control mode exceeds this correction value. Before correcting the primary air control command based on the cold air damper, the primary air velocity at multiple outlets of the coal mill must be considered. Therefore, in addition to meeting the above conditions, this disclosure also requires that the average primary air velocity at multiple outlets of the coal mill is greater than or equal to a first velocity threshold, and the primary air velocity at any of the multiple outlets of the coal mill is greater than a second velocity threshold. This disclosure does not limit the magnitude of the first and second velocity thresholds.

[0059] Optionally, the correction of the primary air control command based on the cold air damper shall be stopped when any one of the following conditions is met: The cold air damper and hot air damper of the coal mill are in manual control mode; The cold air damper correction function of the coal mill is in the off mode; The cold air damper's command value is less than or equal to the cold air damper's correction value; The average primary air velocity at multiple outlets of the coal mill is less than the first air velocity threshold. The primary wind speed at any of the multiple outlets of the coal mill is less than or equal to the second wind speed threshold. The average variation of the primary wind speed at multiple outlets of the coal mill is greater than or equal to the third wind speed threshold.

[0060] For example, when any one of the above conditions is met, the correction of the primary air control command based on the cold air damper can be stopped, wherein the change in the average primary air velocity of the multiple outlets of the coal mill refers to the difference between the average primary air velocity of the multiple outlets at the current moment and the average primary air velocity of the multiple outlets at the previous moment.

[0061] Figure 7 This is a flowchart illustrating a primary air volume control method for a coal mill according to an exemplary embodiment. Figure 7 As shown, step S109 includes the following steps: In step S1091, the deviation between the cold air control valve command value and the cold air control valve correction value of the coal mill is determined.

[0062] In step S1092, the primary air control command is corrected based on the deviation value.

[0063] For example, when correcting the primary air control command based on the cold air damper of the coal mill, the primary air control command can be corrected based on the deviation between the cold air damper command value and the cold air damper correction value. For instance, the cold air damper command value is filtered by a second-order filter (120 seconds) and the cold air damper correction value are simultaneously sent to the regulator to calculate the deviation between the two. When the deviation value is greater than 0, the deviation value can be used as a signal to correct the primary air control command, thereby reducing the opening of the hot air damper of the coal mill and lowering the primary air velocity at the coal mill outlet.

[0064] Furthermore, when any condition for stopping the correction of the primary air control command based on the cold air damper is met, the process of correcting the primary air control command based on the cold air damper of the coal mill will automatically terminate, and after a specified time, it will be re-evaluated whether the coal mill meets the condition for correcting the primary air control command based on the cold air damper, and this process will be repeated in a loop.

[0065] The method may further include: when the cold air damper of the coal mill is closed for a long time, that is, when the duration of the cold air damper opening is 0% is greater than a specified duration threshold, and the average primary air velocity at multiple outlets of the coal mill is less than the first air velocity threshold, the primary air control command can be corrected to increase the primary air velocity at the coal mill inlet; when the opening of the cold air damper is greater than or equal to a set opening threshold, the logic command can be controlled to stop.

[0066] The above technical solution determines the primary air velocity command of the coal mill based on the primary air velocity at each of its multiple outlets; it also determines the primary air velocity command based on the coal feeder's feeding command; and finally, it determines the primary air control command based on the first and / or second primary air velocity commands. The opening of the hot air damper of the coal mill is then adjusted according to the primary air control command to control the primary air volume at the coal mill inlet. By adjusting the primary air volume at the coal mill inlet using the primary air velocity at the coal mill outlet, the synchronization between the primary air volume and the coal mill load can be better maintained, thereby reducing the possibility of malfunctions during coal mill operation.

[0067] Figure 8 This is a schematic diagram of a primary air volume control device 800 for a coal mill, according to an exemplary embodiment. Figure 8 As shown, the device 800 includes: a first determining module 810, a second determining module 820, a third determining module 830, and a control module 840; wherein: The first determining module 810 is used to determine the primary air velocity first command of the coal mill based on the primary air velocity of each of the multiple outlets of the coal mill. The second determining module 820 is used to determine the primary air speed second command of the coal mill according to the coal feeding command of the coal feeder; The third determining module 830 is used to determine the primary air control command of the coal mill based on the first primary air speed command and / or the second primary air speed command; The control module 840 is used to adjust the opening of the hot air damper of the coal mill according to the primary air control command, so as to control the primary air volume at the inlet of the coal mill.

[0068] Optionally, the second determining module 820 is used to determine the primary air speed second command based on the coal feeding type and coal feeding amount of the coal mill; the coal feeding command includes the coal feeding type and coal feeding amount.

[0069] Optionally, the second determining module 820 is further configured to: Obtain the manually input wind speed correction command from the coal mill; The primary wind speed second command is modified according to the wind speed correction command.

[0070] Optionally, the third determining module 830 includes: a calculation submodule and a determining submodule; This calculation submodule is used to determine the deviation between the first primary wind speed command and the second primary wind speed command; This determination submodule is used to determine the primary air control command based on the coal feeding command and the deviation value.

[0071] Optionally, the device also includes an instruction correction module; The instruction correction module is used to correct the primary air control instruction based on the primary air speed when the primary air speed at the first outlet of the coal mill is less than the air speed threshold; the first outlet is any one of the multiple outlets of the coal mill.

[0072] Optionally, the instruction correction module includes: a judgment submodule and an instruction correction submodule; This judgment submodule is used to determine whether the coal mill meets the conditions for correcting the primary air control command according to the cold air damper; This instruction correction submodule is used to correct the primary air control instruction based on the cold air damper of the coal mill when the condition is met.

[0073] Optionally, the conditions for modifying the primary air control command based on the cooling air damper include: The cold air damper and hot air damper of the coal mill are in automatic control mode; The cold air regulating damper correction function of the coal mill is in operation mode; The cold air damper's command value is greater than its correction value. The average primary air velocity at multiple outlets of the coal mill is greater than or equal to the first air velocity threshold. The primary wind speed at any of the multiple outlets of the coal mill is greater than the second wind speed threshold.

[0074] Optionally, this instruction modifies the submodule and is also used for: Determine the deviation between the cold air control valve command value and the cold air control valve correction value of the coal mill; The primary air control command is corrected based on the deviation value.

[0075] Optionally, the correction of the primary air control command based on the cold air damper shall be stopped when any one of the following conditions is met: The cold air damper and hot air damper of the coal mill are in manual control mode; The cold air damper correction function of the coal mill is in the off mode; The cold air damper's command value is less than or equal to the cold air damper's correction value; The average primary air velocity at multiple outlets of the coal mill is less than the first air velocity threshold. The primary wind speed at any of the multiple outlets of the coal mill is less than or equal to the second wind speed threshold. The average variation of the primary wind speed at multiple outlets of the coal mill is greater than or equal to the third wind speed threshold.

[0076] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0077] The above technical solution determines the primary air velocity command of the coal mill based on the primary air velocity at each of its multiple outlets; it also determines the primary air velocity command based on the coal feeder's feeding command; and finally, it determines the primary air control command based on the first and / or second primary air velocity commands. The opening of the hot air damper of the coal mill is then adjusted according to the primary air control command to control the primary air volume at the coal mill inlet. By adjusting the primary air volume at the coal mill inlet using the primary air velocity at the coal mill outlet, the synchronization between the primary air volume and the coal mill load can be better maintained, thereby reducing the possibility of malfunctions during coal mill operation.

[0078] Figure 9 This is a schematic diagram illustrating an electronic device 900 according to an exemplary embodiment. For example... Figure 9 As shown, the electronic device 900 may include a processor 901 and a memory 902. The electronic device 900 may also include one or more of a multimedia component 903, an input / output (I / O) interface 904, and a communication component 905.

[0079] The processor 901 controls the overall operation of the electronic device 900 to complete all or part of the steps in the aforementioned coal mill primary air volume control method. The memory 902 stores various types of data to support the operation of the electronic device 900. This data may include, for example, instructions for any application or method operating on the electronic device 900, and application-related data such as contact data, sent and received messages, pictures, audio, video, etc. The memory 902 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Multimedia component 903 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 902 or transmitted via communication component 905. The audio component also includes at least one speaker for outputting audio signals. I / O interface 904 provides an interface between processor 901 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 905 is used for wired or wireless communication between the electronic device 900 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IoT, eMTC, or other 5G technologies, or combinations thereof, is not limited here. Therefore, the corresponding communication component 905 may include: a Wi-Fi module, a Bluetooth module, an NFC module, etc.

[0080] In an exemplary embodiment, the electronic device 900 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the above-described coal mill primary air volume control method.

[0081] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the coal mill primary air volume control method described above. For example, the computer-readable storage medium may be the memory 902 including program instructions, which may be executed by the processor 901 of the electronic device 900 to complete the coal mill primary air volume control method described above.

[0082] In another exemplary embodiment, a computer program product is also provided, which includes a computer program executable by a programmable device, the computer program having a code portion for performing the above-described coal mill primary air volume control method when executed by the programmable device.

[0083] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0084] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0085] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for controlling the primary air volume of a coal mill, characterized in that, include: The primary air velocity first command of the coal mill is determined based on the primary air velocity at each of the multiple outlets of the coal mill; the primary air velocity first command is obtained by multiplying the average primary air velocity of the multiple outlets by a specified coefficient; The primary air speed of the coal mill is determined according to the coal feeding instruction of the coal feeder; the coal feeding instruction includes the coal feeding type and the coal feeding quantity. Determine the deviation between the first primary wind speed command and the second primary wind speed command; The primary air control command is determined based on the coal feeding command and the deviation value; The opening of the hot air damper of the coal mill is adjusted according to the primary air control command to control the primary air volume at the coal mill inlet; Determine whether the coal mill meets the condition of correcting the primary air control command according to the cold air damper; Under the condition that the above conditions are met, determine the deviation between the cold air control command value and the cold air control correction value of the coal mill cold air control valve; and correct the primary air control command according to the deviation value. The conditions for correcting the primary air control command based on the cold air damper include: The cold air damper and hot air damper of the coal mill are in automatic control mode; The cold air damper correction function of the coal mill is in operation mode; The cold air control valve's cold air control valve command value is greater than the cold air control valve correction value; The average primary wind speed at the multiple outlets of the coal mill is greater than or equal to the first wind speed threshold. The primary wind speed at any of the multiple outlets of the coal mill is greater than the second wind speed threshold.

2. The method according to claim 1, characterized in that, The step of determining the second command for the primary air speed of the coal mill based on the coal feeder's feeding command includes: The second command for primary air speed is determined based on the coal feed type and coal feed rate of the coal mill.

3. The method according to claim 1, characterized in that, After determining the second command for the primary air velocity of the coal mill based on the coal feeder's coal feeding command, the method further includes: Obtain the manually input wind speed correction command from the coal mill; The primary wind speed second command is modified according to the wind speed correction command.

4. The method according to claim 1, characterized in that, The method further includes: When the primary air velocity at the first outlet of the coal mill is less than the air velocity threshold, the primary air control command is corrected according to the primary air velocity; the first outlet is any one of the multiple outlets of the coal mill.

5. The method according to claim 4, characterized in that, The method further includes: The correction of the primary air control command based on the cold air damper shall cease when any one of the following conditions is met: The cold air damper and hot air damper of the coal mill are in manual control mode; The cold air damper correction function of the coal mill is in the off mode; The cold air damper command value is less than or equal to the cold air damper correction value; The average primary wind speed at the multiple outlets of the coal mill is less than the first wind speed threshold. The primary wind speed at any of the multiple outlets of the coal mill is less than or equal to the second wind speed threshold. The change in the average primary wind speed at the multiple outlets of the coal mill is greater than or equal to the third wind speed threshold.

6. A primary air volume control device for a coal mill, characterized in that, include: The first determining module is used to determine a first command for the primary air velocity of the coal mill based on the primary air velocity of each of the multiple outlets of the coal mill; the first command for the primary air velocity is obtained by multiplying the average primary air velocity of the multiple outlets by a specified coefficient. The second determining module is used to determine the primary air speed second command of the coal mill according to the coal feeding command of the coal feeder; the coal feeding command includes the coal feeding type and the coal feeding amount; The third determining module is used to determine the deviation value between the first primary air speed command and the second primary air speed command; and to determine the primary air control command based on the coal feeding command and the deviation value. The control module is used to adjust the opening of the hot air damper of the coal mill according to the primary air control command, so as to control the primary air volume at the inlet of the coal mill. The control module is also used to determine whether the coal mill meets the condition of correcting the primary air control command according to the cold air damper; Under the condition that the above conditions are met, determine the deviation between the cold air control command value and the cold air control correction value of the coal mill cold air control valve; and correct the primary air control command according to the deviation value. The conditions for correcting the primary air control command based on the cold air damper include: The cold air damper and hot air damper of the coal mill are in automatic control mode; The cold air damper correction function of the coal mill is in operation mode; The cold air control valve's cold air control valve command value is greater than the cold air control valve correction value; The average primary wind speed at the multiple outlets of the coal mill is greater than or equal to the first wind speed threshold. The primary wind speed at any of the multiple outlets of the coal mill is greater than the second wind speed threshold.

7. A non-transitory computer-readable storage medium having computer program instructions stored thereon, characterized in that, When executed by a processor, the computer program instructions implement the steps of the method described in any one of claims 1-5.

8. An electronic device, characterized in that, include: A memory on which computer programs are stored; A processor for executing the computer program in the memory to implement the steps of the method according to any one of claims 1-5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-5.

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