Primary air system control method, system, device and storage medium

Abstract

The application discloses a primary air system control method, system, device and storage medium. The method comprises the following steps: determining the combustion stability indexes of a plurality of burners, the current offset-burning burners of each layer and the ignition distances of the current offset-burning burners according to the flame temperatures of the burners at a plurality of target positions of a current boiler; determining the current target ignition distance of the current offset-burning burners according to the combustion stability indexes of the plurality of burners and the ignition distance of the current offset-burning burners for each layer of the current offset-burning burners; determining the target opening of the primary air hot air damper corresponding to the current offset-burning burners through a primary air hot air optimization model and the current target ignition distance of the current offset-burning burners for each layer of the current offset-burning burners; and controlling the distributed control system to adjust the primary air hot air damper corresponding to the current offset-burning burners according to the target opening of the primary air hot air damper corresponding to the current offset-burning burners. The method improves offset burning and ensures the safe operation of a thermal power generating unit.

Description

Technical Field

[0001] This application relates to the field of thermal power unit technology, and in particular to a primary air system control method, system, device and storage medium. Background Technology

[0002] In thermal power plants, tangentially fired boilers (hereinafter referred to as boilers) require uniform heating during normal operation, but uneven flame distribution may occur. If this uneven burning persists, it will cause uneven heating of the water-cooled walls within the furnace, keeping the affected area under overheating conditions, significantly increasing the probability of tube rupture and affecting the safety of the thermal power unit. Therefore, maintaining a centered combustion circle and mitigating uneven burning are extremely important for tangentially fired boilers.

[0003] Currently, most power plants in China require a single air leveling test after shutdown to improve uneven combustion. However, this test is often only conducted when the combustion system of the thermal power unit has been modified or when uneven combustion is severe. Because thermal power units need to complete their power generation tasks, in most cases, an air leveling test can only be performed during planned shutdowns, resulting in delayed improvements to uneven combustion. Furthermore, this single air leveling test is an offline optimization, only guaranteeing the combustion circle effect for a limited period after adjustment. As the unit operates, the status of burners and other equipment changes, and power plants lack online monitoring methods to understand these changes in combustion status in a timely manner, as well as reliable adjustment criteria to improve uneven combustion. Summary of the Invention

[0004] This application provides a primary air system control method, system, device, and storage medium to address the problem that improving boiler eccentricity through primary air leveling tests in thermal power units is not timely and can only guarantee the combustion circle effect for a period of time after adjustment. As the unit operates, the status of equipment such as burners changes, and power plants lack online observation means to understand the changes in combustion status in a timely manner, as well as reliable adjustment basis to improve the problem of eccentricity.

[0005] In a first aspect, this application provides a primary air system control method, the method comprising:

[0006] Based on the flame temperatures of burners at multiple target locations in the current boiler, the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner are determined; wherein, the flame temperature is obtained from a spectral detection system, the burners at multiple target locations are arranged in layers on the current boiler, and the combustion stability index is used to measure the combustion stability of the multiple burners.

[0007] For each layer of the current off-center burner, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner.

[0008] For each layer of the current off-center burner, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is determined by the primary air hot air optimization model and the current target ignition distance of the current off-center burner; wherein, the primary air hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air hot air damper corresponding to the burner and the ignition distance.

[0009] The distributed control system adjusts the primary air hot air damper corresponding to the current off-center burner according to the target opening degree of the primary air hot air damper corresponding to the current off-center burner.

[0010] Secondly, this application provides a primary air system control system, including a server, a spectral detection system, and a distributed control system; wherein the server is connected to both the spectral detection system and the distributed control system.

[0011] The server is used to implement the primary air system control method as described in the first aspect of this application;

[0012] The spectral detection system is used to detect the flame temperature of burners at multiple target locations in the current boiler under the control of the server.

[0013] The distributed control system is used, under the control of the server, to adjust the primary air hot air damper corresponding to the current off-center burner according to the target opening degree of the primary air hot air damper corresponding to the current off-center burner.

[0014] Thirdly, this application provides a primary air system control device, comprising:

[0015] The determination module is used to determine the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler. The flame temperature is obtained from a spectral detection system, the burners at the multiple target locations are arranged in layers on the current boiler, and the combustion stability index is used to measure the combustion stability of the multiple burners.

[0016] The target distance determination module is used to determine the current target ignition distance of the current off-center burner for each layer based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner.

[0017] The target opening determination module is used to determine the target opening of the primary air and hot air damper corresponding to the current off-center burner for each layer, based on the primary air and hot air optimization model and the current target ignition distance of the current off-center burner; wherein, the primary air and hot air optimization model is used to indicate the mapping relationship between the opening of the primary air and hot air damper corresponding to the burner and the ignition distance.

[0018] The control module is used to control the distributed control system to adjust the primary air hot air damper corresponding to the current eccentric burner according to the target opening degree of the primary air hot air damper corresponding to the current eccentric burner.

[0019] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the primary air system control method as described in any of the present application.

[0020] The proposed solution determines the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler. The flame temperature is obtained from a spectral detection system. The burners at multiple target locations are arranged in layers on the current boiler. The combustion stability index is used to measure the combustion stability of the multiple burners. For each layer of the current off-center burner, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner. For each layer of the current off-center burner, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined through a primary air / hot air optimization model and the current target ignition distance of the current off-center burner. The primary air / hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air / hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air / hot air damper corresponding to the current off-center burner based on the target opening degree of the primary air / hot air damper corresponding to the current off-center burner. The proposed solution, on the one hand, can determine the combustion stability indicators of multiple burners, the current off-center burners on each layer, and the ignition distance of the current off-center burners based on the burner flame temperature, enriching the means of sensing combustion information and providing a data foundation for adjusting the primary air system. On the other hand, it can also determine the target opening degree of the primary air and hot air dampers based on the current target ignition distance and the primary air and hot air optimization model, realizing fine-tuning of the primary air system and providing adjustment data for improving boiler off-center burning, which helps to improve boiler off-center burning. Furthermore, it can control the distributed control system to adjust the primary air and hot air dampers according to the target opening degree, reducing the workload of personnel and ensuring the safe operation of thermal power units. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the primary air system control method provided in this application;

[0023] Figure 2 This is an exemplary structural diagram of the primary air system control method provided in this application;

[0024] Figure 3 This is an exemplary structural diagram of the primary air system control method provided in this application;

[0025] Figure 4 This is an exemplary structural diagram of the primary air system control method provided in this application;

[0026] Figure 5 This is an example diagram illustrating the target opening confirmation process of a primary air hot air damper in the primary air system control method provided in this application.

[0027] Figure 6 This is another schematic diagram of the primary air system control method provided in this application;

[0028] Figure 7 This is an exemplary control composition diagram of a primary air system for the primary air system control method provided in this application;

[0029] Figure 8 This is another exemplary control composition diagram of a primary air system provided in this application for the primary air system control method;

[0030] Figure 9 This is a schematic diagram of the structure of the primary air system control system provided in this application;

[0031] Figure 10 This is another structural schematic diagram of the primary air system control system provided in this application;

[0032] Figure 11 This is a schematic diagram of the structure of the primary air system control device provided in this application;

[0033] Figure 12 This is a schematic diagram of the structure of an exemplary server provided in this application. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present application, not the entire structure.

[0035] Figure 1 This is a flowchart illustrating a primary air system control method provided in this application. This method can be executed by a primary air system control device provided in this application, which can be implemented using software and / or hardware. In a specific embodiment, the device can be integrated into a server. For example, the server can be a computer, etc. The following embodiments will illustrate this using the integration of the device into a server as an example.

[0036] refer to Figure 1 The method may specifically include the following steps:

[0037] Step 101: Based on the flame temperature of the burners at multiple target locations in the current boiler, determine the combustion stability index of multiple burners, the current off-center burner on each floor, and the ignition distance of the current off-center burner.

[0038] Among them, the flame temperature is obtained from the spectral detection system, and the burners at multiple target locations are set in layers on the current boiler. The combustion stability index is used to measure the combustion stability of multiple burners.

[0039] Specifically, after obtaining the flame temperature of the burners at multiple target locations of the current boiler from the spectral detection system, the combustion stability index of multiple burners is calculated based on the flame temperature, and the current off-center burner and the ignition distance of the current off-center burner are determined for each layer.

[0040] Optionally, determining the combustion stability index of multiple burners based on the flame temperature of the burners at multiple target locations of the current boiler may include steps 1011 to 1015.

[0041] Step 1011: Construct axial flow field models of burners at multiple target locations in the current boiler based on the gas phase flow conservation equation in cylindrical coordinates.

[0042] Specifically, for each burner, an axial flow field model is constructed based on the gas phase flow conservation equation in cylindrical coordinates.

[0043] Step 1012: Correct the axial flow field model based on the flame temperature of the burners at multiple target locations of the current boiler to obtain the axial temperature field of each burner.

[0044] Multiple target locations are set on different axes of the furnace of the current boiler, and any point on the axial temperature field corresponds to a temperature value.

[0045] Specifically, the flame temperatures of the burners at multiple target locations in the current boiler are added to the axial flow field model to obtain the axial temperature field of each burner.

[0046] Step 1013: Obtain the temperature values ​​of temperature points on the axial temperature field of multiple burners located on the same axis in the furnace at multiple target locations.

[0047] Specifically, the furnace has multiple axes, and there are multiple burners on the same axis. The temperature values ​​of the temperature points on the axial temperature field of the multiple burners at the same axis position are obtained respectively.

[0048] For example, for such Figure 2 The illustrated tangentially shaped boiler has burners that ignite the boiler in a tangential pattern. Burners at multiple target locations are arranged in layers on the current boiler. Figure 2 The following example illustrates the situation where six layers of burners are arranged in both the Chinese and Israeli configurations. Each layer can contain multiple burners. Figure 2 Taking an example where each layer contains four burners, the burners in each layer are located at the four corners of the circumscribed square inside the furnace. Figure 2 The system includes corner burners (1, 2, 3, and 4), each with a corresponding ignition distance and flame temperature. Burners in each layer can operate in combination; for example, if only layers A, B, C, and D burners are operating, the operating combination is A, B, C, and D. Temperature values ​​at points on the axial temperature field of multiple burners located at the same corner are obtained. It should be noted that this embodiment does not limit the total number of burners, the number of layers, or the number of burners in each layer.

[0049] Step 1014: For multiple burners on the same axis, determine the standard deviation of the temperature values ​​at temperature points located on the same parallel axis, and determine the standard deviation of the temperature values ​​of multiple burners on the same axis based on the standard deviation of the temperature values ​​at multiple parallel axes.

[0050] Among them, the parallel axis is a line parallel to the central axis of the furnace.

[0051] Specifically, for multiple burners on the same axis, multiple parallel axes can pass through the same positions of the multiple burners. The temperature values ​​of multiple temperature points on the same parallel axis are determined, and the standard deviation of these temperature values ​​is calculated. This standard deviation is then used to determine the temperature value standard deviation of the multiple burners on the same axis. In this embodiment, statistical parameters of the standard deviation of the temperature values ​​at multiple parallel axes, such as the maximum, median, and mean of the standard deviations, can be used to determine the temperature value standard deviation of the multiple burners on the same axis. For example, the determination method can be to calculate the standard deviation of the temperature values ​​at multiple parallel axes again to obtain the temperature value standard deviation of the multiple burners on the same axis.

[0052] For example, in Figure 3 In the diagram, lines A, B, and C are parallel axes. The standard deviations of the temperature values ​​of multiple burners on line A, line B, and line C are obtained. Then, based on these standard deviations, the standard deviations are calculated again to obtain the following result: Figure 3 Standard deviation of temperature values ​​for the six burners.

[0053] Step 1015: Determine the combustion stability index based on the standard deviation of the temperature values ​​of multiple burners on multiple axes.

[0054] Specifically, after obtaining the standard deviations of temperature values ​​from multiple burners along multiple axes, the combustion stability index is calculated based on these standard deviations. The calculation method can include averaging, calculating the variance, or weighted summation.

[0055] Optionally, determining the current off-center burner and the ignition distance of the current off-center burner for each layer based on the flame temperature of the burners at multiple target locations of the current boiler may include steps 1016 to 1018.

[0056] Step 1016: In the axial temperature field of each burner, along the direction of the axial temperature field, compare the multiple temperature values ​​corresponding to multiple points on the central axis of the burner with the initial hot air temperature, and determine the point corresponding to the first temperature value that is greater than the initial hot air temperature as the ignition point of the burner.

[0057] The axial temperature field is oriented from the burner to the target point on the central axis of the current boiler. The target point is the intersection of the central axis of the current boiler and the central axis of the burner.

[0058] Specifically, the initial hot air temperature is a preset temperature value used to determine the ignition point in the generator set. In the axial temperature field of each burner, multiple points on the burner's central axis correspond to multiple temperature values. Along the direction of the axial temperature field, these multiple temperature values ​​at the points on the burner's central axis are compared with the initial hot air temperature. The point corresponding to the first temperature value greater than the initial hot air temperature is the burner's ignition point.

[0059] Step 1017: For each burner, the distance between the ignition point of the burner and the point on the burner's axis closest to the center of the furnace is taken as the ignition distance of each burner.

[0060] For example, such as Figure 4 As shown, point A is the point on the burner's axis closest to the center of the furnace, and point B is the ignition point of the burner. The distance between point A and point B is the ignition distance of the burner.

[0061] Step 1018: For the burners at multiple target locations in each layer, determine the current off-center burner of the layer based on the ignition distance of the burners at multiple target locations.

[0062] Specifically, the ignition distances of burners at multiple target locations on each layer are calculated, or their magnitudes are directly compared, to determine the current off-center burner on the layer.

[0063] Optionally, determining the current off-center burner of a layer based on the ignition distance of burners at multiple target locations may include steps 81 to 82.

[0064] Step 81: Determine whether the current boiler is experiencing uneven burning based on the variance of the ignition distance of the burners at multiple target locations.

[0065] Specifically, for burners at multiple target locations on each floor, after obtaining the ignition distances of the burners at these multiple target locations, the variance of the ignition distances for each floor's burners at these multiple target locations is calculated. Based on the variance of the ignition distances of the burners at multiple target locations, it is determined whether the current boiler is experiencing uneven burning. The preset variance can be a variance value determined empirically for the thermal power unit, or it can be the variance value of the ignition distance obtained after the current boiler's initial ignition. The calculated variance is compared with the preset variance; if the calculated variance is greater than the preset variance, it indicates that uneven burning has occurred.

[0066] Step 82: After determining that the current boiler is experiencing uneven burning, determine the current unevenly burning burner in the layer based on the deviation between the ignition distance of multiple burners and the preset ignition distance.

[0067] Specifically, the preset ignition distance can be the ignition distance determined by the staff of the thermal power unit through experience, or it can be the ignition distance obtained after the current boiler is initially ignited. After determining that the current boiler is burning off-center, the deviation values ​​between the ignition distance of multiple burners and the preset ignition distance are determined. The burner with the largest deviation value is determined as the burner burning off-center on that floor.

[0068] Step 102: For each layer of the current off-center burner, determine the current target ignition distance of the current off-center burner based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner.

[0069] Specifically, for each layer of the current off-center burner, the current target ignition distance of the current off-center burner can achieve the purpose of stabilizing flame combustion and improving off-center burning. Therefore, based on the combustion stability indicators of multiple burners and the ignition distance of the current off-center burner, the current target ignition distance of the current off-center burner can be determined.

[0070] Optionally, for each layer of the current off-center burner, determining the current target ignition distance of the current off-center burner based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner may include steps 1021 to 1022.

[0071] Step 1021: Based on the characteristics of the current boiler and the preset mapping relationship between boiler characteristics and ignition distance optimization rules, determine the ignition distance optimization rules for the current boiler.

[0072] Specifically, the preset mapping relationship between boiler characteristics and ignition distance optimization rules is established based on the preset operating procedures of thermal power units, the current boiler's instruction manual, and historical data. Based on the current boiler's characteristics and the preset mapping relationship between boiler characteristics and ignition distance optimization rules, the ignition distance optimization rules for the current boiler are determined.

[0073] Step 1022: Determine the current target ignition distance based on the current ignition distance of the off-center burner, the combustion stability index of multiple burners, the burner's grinding operation combination, and the current boiler's ignition distance optimization rules.

[0074] Specifically, the burner grinding operation combination refers to the combination of burners currently in operation. The ignition distance of the current off-center burner, the combustion stability index of multiple burners, and the burner grinding operation combination are used to characterize the ignition status of the current off-center burner. Combined with the current boiler ignition distance optimization rules, the current target ignition distance can be determined.

[0075] For example, such as Figure 2As shown, when only burners in layers A, B, C, and D are operating, the mill operation combination is mill A, B, C, and D operation.

[0076] Step 103: For each layer of the current off-center burner, determine the target opening degree of the primary air hot air damper corresponding to the current off-center burner by using the primary air hot air optimization model and the current target ignition distance of the current off-center burner.

[0077] Among them, the primary air hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air hot air damper corresponding to the burner and the ignition distance.

[0078] Specifically, after obtaining the current target ignition distance of the current off-center burner, the target opening degree of the primary air hot air damper corresponding to the current off-center burner can be determined based on the primary air hot air optimization model and the current target ignition distance of the current off-center burner.

[0079] Optionally, for each layer of the current off-center burner, determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner through the primary air hot air optimization model and the current target ignition distance of the current off-center burner may include steps 1031 to 1034.

[0080] Step 1031: In the primary air-heat optimization model, adjust the opening of the primary air-heat damper to obtain the ignition distance output by the primary air-heat optimization model.

[0081] The inputs to the primary air-hot air optimization model are pulverized coal fineness, primary air pressure, primary air flow rate, primary air-hot air flow rate, the temperature of the current eccentric burner layer, and the opening degree of the primary air-hot air damper. The output of the primary air-hot air optimization model is the ignition distance. Since the pulverized coal fineness, primary air pressure, primary air flow rate, primary air-hot air flow rate, and the temperature of the current eccentric burner layer are all fixed values, adjusting the opening degree of the primary air-hot air damper will correspondingly adjust the ignition distance output by the primary air-hot air optimization model.

[0082] Specifically, in the primary air-heat air optimization model, the opening degree of the primary air-heat air damper is input to obtain the corresponding ignition distance output by the primary air-heat air optimization model.

[0083] For example, the adjustment method for the opening of the primary air hot air damper can be iterative adjustment.

[0084] Step 1032: Determine whether the absolute value of the difference between the ignition distance output by the primary wind-heat optimization model and the current target ignition distance is less than the preset distance difference.

[0085] For example, the preset distance difference can be 5cm.

[0086] Specifically, the ignition distance output by the primary air hot air damper optimization model after inputting the primary air hot air damper opening is calculated against the current target ignition distance. It is then determined whether the absolute value of the difference between the ignition distance output by the primary air hot air optimization model and the current target ignition distance is less than a preset distance difference.

[0087] Step 1033: When the absolute value of the difference between the ignition distance output by the primary wind-heat optimization model and the current target ignition distance is greater than or equal to the preset distance difference, return to step 1031.

[0088] Specifically, when the absolute value of the difference between the ignition distance output by the primary air hot air optimization model and the current target ignition distance is greater than or equal to the preset distance difference, it indicates that the opening of the primary air hot air damper cannot meet the requirements and the opening of the primary air hot air damper needs to be further adjusted. Therefore, return to step 1031.

[0089] Step 1034: When the absolute value of the difference between the ignition distance output by the primary air hot air optimization model and the current target ignition distance is less than the preset distance difference, the corresponding primary air hot air damper opening is taken as the target opening of the primary air hot air damper.

[0090] Specifically, when the absolute value of the difference between the ignition distance output by the primary air-hot air optimization model and the current target ignition distance is less than the preset distance difference, it indicates that the opening of the primary air-hot air damper at this time can meet the requirements, that is, the output ignition distance can meet the requirements. Therefore, the opening of the primary air-hot air damper at this time is taken as the target opening of the primary air-hot air damper.

[0091] For example, the process of determining the target opening degree of the primary air heating damper is as follows: Figure 5 As shown, the current target ignition distance is determined based on the current ignition distance of the off-center burner, the combustion stability indicators of multiple burners, the burner mill operation combination, and the current boiler ignition distance optimization rules. Then, in the primary air-hot air optimization model, the primary air-hot air damper opening is used as the optimization variable, while pulverized coal fineness, primary air pressure, primary air flow rate, primary air-hot air flow rate, and the temperature of the current off-center burner layer are used as other invariants to obtain the output variable, ignition distance. Specifically, the flame temperature of all burners in the current off-center burner layer can be obtained first, and then the average flame temperature of all burners can be calculated. This average value is then used as the temperature of the current off-center burner layer. By changing the primary air-hot air damper opening until the absolute value of the difference between the obtained ignition distance and the current target ignition distance is less than a preset distance difference, the opening of the primary air-hot air damper at this point is taken as the target opening of the primary air-hot air damper.

[0092] Optionally, when the operating mode is determined to be open-loop operating mode, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is sent to the user.

[0093] Specifically, after determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner, the operating mode is determined. The operating mode is preset by the user. When the operating mode is determined to be open-loop operating mode, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is sent to the user to guide the user in adjusting the primary air system and reduce the user's workload.

[0094] Optionally, when the operating mode is determined to be a closed-loop operating mode, the steps for determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner in the distributed control system are as follows.

[0095] Specifically, after determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner, the operating mode is determined. The operating mode is preset by the user. When the operating mode is determined to be a closed-loop operating mode, the steps for executing the distributed control system based on the target opening degree of the primary air hot air damper corresponding to the current off-center burner are determined.

[0096] Step 104: The distributed control system adjusts the primary air hot air damper corresponding to the current eccentric burner according to the target opening degree of the primary air hot air damper corresponding to the current eccentric burner.

[0097] Specifically, after obtaining the target opening degree of the primary air hot air damper, the distributed control system adjusts the primary air hot air damper corresponding to the current off-center burner based on the target opening degree. This enables automatic closed-loop optimization of the primary air system without manual operation, further reducing the user's workload.

[0098] The proposed solution determines the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler. The flame temperature is obtained from a spectral detection system. The burners at multiple target locations are arranged in layers on the current boiler. The combustion stability index is used to measure the combustion stability of the multiple burners. For each layer of the current off-center burner, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner. For each layer of the current off-center burner, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined through a primary air / hot air optimization model and the current target ignition distance of the current off-center burner. The primary air / hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air / hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air / hot air damper corresponding to the current off-center burner based on the target opening degree of the primary air / hot air damper corresponding to the current off-center burner. The proposed solution, on the one hand, can determine the combustion stability indicators of multiple burners, the current off-center burners on each layer, and the ignition distance of the current off-center burners based on the burner flame temperature, enriching the means of sensing combustion information and providing a data foundation for adjusting the primary air system. On the other hand, it can also determine the target opening degree of the primary air and hot air dampers based on the current target ignition distance and the primary air and hot air optimization model, realizing fine-tuning of the primary air system and providing adjustment data for improving boiler off-center burning, which helps to improve boiler off-center burning. Furthermore, it can control the distributed control system to adjust the primary air and hot air dampers according to the target opening degree, reducing the workload of personnel and ensuring the safe operation of thermal power units.

[0099] Figure 6 This is another schematic flowchart of the primary air system control method provided in this application. This embodiment... Figure 1 Based on the illustrated embodiments and various optional implementation schemes, this paper provides a detailed explanation of how to control flame temperature, and how to adjust the opening of the primary air cooling damper. Figure 6 As shown, the method may include the following steps:

[0100] Step 201: Control the spectral detection system to detect the flames of the burners at multiple target locations of the current boiler, and obtain the flame temperatures of the burners at multiple target locations of the current boiler.

[0101] Among them, the flame temperature of the burners at multiple target locations of the current boiler is calculated by the spectral detection system after detecting the flame spectrum of the burners at multiple target locations of the current boiler. The spectral detection system is a detection system calibrated by the gray body radiation band.

[0102] Specifically, the control spectral detection system detects the flames of burners at multiple target locations in the current boiler. After detecting the flame spectra of the burners at these multiple target locations, the spectral detection system calculates the flame temperatures of the burners at these multiple target locations in the current boiler. The flame temperatures of the burners at multiple target locations in the current boiler obtained by the spectral detection system are then acquired.

[0103] For example, the control of the primary air system of a thermal power unit mainly includes, as follows: Figure 7 The two aspects are illustrated. First, the primary air pressure is adjusted by using a frequency converter or by adjusting the primary air damper. Second, as... Figure 8 As shown, the main factors for primary air hot air control include ignition distance, pulverized coal fineness, primary air pressure, primary air flow rate, primary air hot air flow rate, primary air hot air damper opening, and the temperature of the layer where the burner is located. The output air volume of primary air hot air is the hot primary air volume. By changing the hot primary air volume, the combustion distance is adjusted, thereby improving the combustion tangency. The main factors for primary air cold air control include the mill outlet mixture temperature, pulverized coal fineness, primary air pressure, primary air flow rate, primary air cold air flow rate, and primary air cold air damper opening. The output air volume of primary air cold air is the cold primary air volume. By changing the cold primary air volume, the mill outlet air-coal mixture temperature is adjusted, the pulverized coal flow is optimized, and malfunctions such as pipe blockage are avoided. Figure 7 As shown, the thermal power unit has six layers of burners: layer A, layer B, layer C, layer D, layer E, and layer F. Each layer contains four burners: corner burners (1-corner, 2-corner, 3-corner, and 4-corner). Each burner corresponds to both primary air for hot and primary air for cold air. The primary air for hot air is controlled by adjusting the primary air for hot air, and the primary air for cold air is controlled by adjusting the primary air for cold air.

[0104] Step 202: Based on the flame temperature of the burners at multiple target locations in the current boiler, determine the combustion stability index of multiple burners, the current off-center burner on each floor, and the ignition distance of the current off-center burner.

[0105] Specifically, after obtaining the flame temperature of the burners at multiple target locations in the current boiler, the combustion stability index of multiple burners is calculated based on the flame temperature, and the current off-center burner and the ignition distance of the current off-center burner are determined for each layer.

[0106] Step 203: For each layer of the current off-center burner, determine the current target ignition distance of the current off-center burner based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner.

[0107] Specifically, for each layer of the current off-center burner, the current target ignition distance of the current off-center burner can achieve the purpose of stabilizing flame combustion and improving off-center burning. Therefore, based on the combustion stability indicators of multiple burners and the ignition distance of the current off-center burner, the current target ignition distance of the current off-center burner can be determined.

[0108] Step 204: For each layer of the current off-center burner, determine the target opening degree of the primary air hot air damper corresponding to the current off-center burner by using the primary air hot air optimization model and the current target ignition distance of the current off-center burner.

[0109] Specifically, after obtaining the current target ignition distance of the current off-center burner, the target opening degree of the primary air hot air damper corresponding to the current off-center burner can be determined based on the primary air hot air optimization model and the current target ignition distance of the current off-center burner.

[0110] Step 205: The distributed control system adjusts the primary air hot air damper corresponding to the current eccentric burner according to the target opening degree of the primary air hot air damper corresponding to the current eccentric burner.

[0111] Specifically, after obtaining the target opening degree of the primary air hot air damper, the distributed control system adjusts the primary air hot air damper corresponding to the current off-center burner based on the target opening degree. This enables automatic closed-loop optimization of the primary air system without manual operation, further reducing the user's workload.

[0112] Step 206: Determine the target opening degree of the primary air cooling damper for multiple burners by using the primary air cooling optimization model and the target mill outlet air-powder mixture temperature.

[0113] Among them, the primary air-cooled air optimization model is used to indicate the mapping relationship between the opening degree of the primary air-cooled air damper corresponding to multiple burners and the temperature of the air-powder mixture at the mill outlet.

[0114] Specifically, the primary air cooling system plays a crucial role in regulating the primary air temperature of the coal mill. It needs to maintain the temperature of the coal-air mixture at the mill outlet within a suitable range to avoid excessively low temperatures, high coal powder viscosity, and malfunctions such as blockage of the coal conveying pipes. The target temperature of the coal-air mixture at the mill outlet is obtained according to the operating procedures of the thermal power unit. Based on the primary air cooling system optimization model and the target temperature of the coal-air mixture at the mill outlet, the target opening degree of the primary air cooling dampers for multiple burners can be determined.

[0115] Optionally, determining the target opening degree of the primary air cooling damper corresponding to multiple burners by using the primary air cooling optimization model and the target mill outlet air-powder mixture temperature may include steps 2061 to 2064.

[0116] Step 2061: In the primary air-cooling optimization model, adjust the opening of the primary air-cooling baffle to obtain the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model.

[0117] The inputs to the primary air-cooling optimization model are pulverized coal fineness, primary air pressure, primary air flow rate, primary air-cooling flow rate, and primary air-cooling damper opening. The output of the primary air-cooling optimization model is the temperature of the pulverized coal mixture at the mill outlet. Since the pulverized coal fineness, primary air pressure, primary air flow rate, and primary air-cooling flow rate are all fixed values, adjusting the primary air-cooling damper opening will correspondingly adjust the temperature of the pulverized coal mixture at the mill outlet output by the primary air-cooling optimization model.

[0118] Specifically, in the primary air-cooling optimization model, the opening degree of the primary air-cooling baffle is input to obtain the temperature of the mill outlet air-powder mixture output by the corresponding primary air-cooling optimization model.

[0119] For example, the adjustment of the opening of the air-cooled damper can be done iteratively.

[0120] Step 2062: Determine whether the absolute value of the difference between the temperature of the air-powder mixture at the mill outlet output by the primary air-cooling optimization model and the temperature of the target air-powder mixture at the mill outlet is less than the preset temperature difference.

[0121] For example, the preset temperature difference can be 5°C.

[0122] Specifically, the temperature of the air-powder mixture at the mill outlet, output by the primary air-cooling damper opening, is calculated in relation to the target temperature of the air-powder mixture at the mill outlet, obtained from the primary air-cooling damper optimization model. The absolute value of the difference between the temperature of the air-powder mixture at the mill outlet output by the primary air-cooling damper optimization model and the target temperature of the air-powder mixture at the mill outlet is then determined to be less than a preset temperature difference.

[0123] Step 2063: When the absolute value of the difference between the temperature of the air-powder mixture at the mill outlet output by the primary air-cooling optimization model and the temperature of the air-powder mixture at the target mill outlet is greater than or equal to the preset temperature difference, return to step 2061.

[0124] Specifically, when the absolute value of the difference between the temperature of the air-powder mixture at the mill outlet output by the primary air-cooling optimization model and the temperature of the air-powder mixture at the target mill outlet is greater than or equal to the preset temperature difference, it indicates that the opening of the primary air-cooling damper cannot meet the requirements and the opening of the primary air-cooling damper needs to be further adjusted. Therefore, return to step 2061.

[0125] Step 2064: When the absolute value of the difference between the temperature of the air-powder mixture at the mill outlet output by the primary air-cooling optimization model and the temperature of the target air-powder mixture at the mill outlet is less than the preset temperature difference, the opening degree of the corresponding primary air-cooling damper is taken as the target opening degree of the primary air-cooling damper for multiple burners.

[0126] Specifically, when the absolute value of the difference between the mill outlet air-powder mixture temperature output by the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature is less than the preset temperature difference, it indicates that the opening degree of the primary air-cooling damper at this time can meet the requirements, that is, the output mill outlet air-powder mixture temperature can meet the requirements. Therefore, the opening degree of the primary air-cooling damper at this time is taken as the target opening degree of the primary air-cooling damper for multiple burners.

[0127] Step 207: The distributed control system adjusts the primary air cooling dampers corresponding to multiple burners according to the target opening of the primary air cooling damper.

[0128] Specifically, after obtaining the target opening degree of the primary air-cooled damper, in one possible implementation, the target opening degree of the primary air-cooled damper is directly sent to the user. In another possible implementation, the distributed control system adjusts the primary air-cooled dampers corresponding to multiple burners based on the target opening degree of the primary air-cooled damper.

[0129] Step 208: Obtain the current maximum coal feed rate of the boiler.

[0130] Specifically, the maximum current coal feed rate of the coal feeder corresponding to the current boiler in the thermal power unit is obtained from the historical data of the thermal power unit.

[0131] Step 209: Determine the target primary air pressure corresponding to the current maximum coal feed rate based on the current maximum coal feed rate of the boiler and the preset mapping relationship between the maximum coal feed rate and the primary air pressure.

[0132] Specifically, based on the historical operating data of the coal feeder of the thermal power unit, the mapping relationship between the maximum coal feed rate and the primary air pressure is obtained. Then, based on the current maximum coal feed rate of the boiler and the preset mapping relationship between the maximum coal feed rate and the primary air pressure, the target primary air pressure corresponding to the current maximum coal feed rate is determined.

[0133] Step 210: The distributed control system adjusts the opening of the primary air damper according to the target primary air pressure.

[0134] Specifically, after obtaining the target primary air pressure, in one possible implementation, the target primary air pressure is directly sent to the user. In another possible implementation, the distributed control system adjusts the opening of the primary air damper. If the primary air pressure is changed by altering the power supply frequency, the distributed control system adjusts the power supply frequency for the primary air pressure based on the target primary air pressure. If the primary air pressure is adjusted, the primary air pressure values ​​in the primary air hot air optimization model in step 204 and the primary air cold air optimization model in step 206 are the adjusted primary air pressures in this step.

[0135] It should be understood that, although Figure 6 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 6 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages does not have to be sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0136] This application's solution utilizes a controlled spectral detection system to detect the flames of burners at multiple target locations in the current boiler, obtaining the flame temperatures of these burners. This provides a method for acquiring burner flame temperatures, expanding the means of sensing combustion information in thermal power plants and helping staff gain a more intuitive understanding of the combustion situation within the furnace, enabling timely detection of abnormalities such as uneven burning. By adjusting the opening of the primary air-cooling damper in the primary air-cooling optimization model, the temperature of the air-coal mixture at the mill outlet is correspondingly adjusted, thereby determining the target opening of the primary air-cooling damper and maintaining the temperature of the air-coal mixture at the mill outlet within a suitable range. This allows for precise regulation of the primary air-cooling, achieving temperature control and preventing malfunctions such as excessively low temperatures, high coal powder viscosity, and blockages in the coal conveying pipes. By determining a suitable primary air pressure and adjusting the primary air damper opening, the primary air pressure is ensured to meet the coal feeding requirements of all coal mills.

[0137] Figure 9 This is a structural schematic diagram of the primary air system control system provided in this application, as shown below. Figure 9 As shown, the primary air system control system includes a server, a spectral detection system, and a distributed control system. The server is connected to both the spectral detection system and the distributed control system.

[0138] The server is used to execute the primary air system control method provided in any of the above embodiments.

[0139] The spectral detection system is used to detect the flame temperature of burners at multiple target locations in the current boiler under the control of a server.

[0140] Optionally, the spectral detection system is specifically used to acquire flame spectra of burners at multiple target locations under the control of a server, and determine the flame temperature based on the wavelength of the flame spectra.

[0141] For example, such as Figure 10 The flame detection probe shown is a fiber optic probe used to collect spectral information of flame radiation. The accompanying spectrometer has a measurement range of 200–1100 nm, covering the visible light spectrum and part of the near-infrared spectrum of flames. The spectral analysis system within the spectrometer uses a two-color method for temperature measurement. Its principle is to calculate the flame temperature by using the absolute radiation intensity corresponding to two different wavelengths of spectral signals from the same radiation source. It can be calculated using Formula 1.

[0142]

[0143] Where λ1 and λ2 are two different wavelengths, I(λ1,T) and I(λ2,T) are the absolute radiation intensities corresponding to the two wavelengths, and ε λ1 and ε λ2 c is the emissivity corresponding to two wavelengths, c2 is Planck's second radiation constant, and T is the temperature of the radiation source.

[0144] The spectral detection system is calibrated before being used to detect flame temperature, which makes the spectral detection system more accurate.

[0145] The calibration process of the spectral detection system is as follows: After acquiring a large number of wavelengths of flame spectrum, when the two wavelengths are λ and λ+Δλ, where Δλ is the difference between the two wavelengths, when Δλ is sufficiently small, it can be considered that the emissivity of the two wavelengths is the same. Formula 2 can be obtained from Formula 1.

[0146]

[0147] By selecting different wavelengths of λ and λ+Δλ from a large number of flame spectra obtained, a continuous flame temperature distribution can be obtained.

[0148] Flame emissivity distribution can be obtained by comparing the absolute flame radiation intensity I(λ,T) acquired and calibrated by a spectrometer with the blackbody radiation intensity I at the same temperature. b The ratio between (λ,T) is given by Formula 3.

[0149]

[0150] After obtaining multiple ε λThe emissivity distribution curve can then be obtained. By observing how the emissivity curve changes with wavelength, if the emissivity remains constant in that wavelength band, the radiation source satisfies the gray body characteristic and can be used to detect the flame temperature. However, the flame heat source of an actual thermal power unit is not an absolute gray body. Therefore, when the fluctuations in temperature and emissivity with wavelength are very small, the calibration can be considered complete. The relative root mean square error of emissivity and temperature is used to quantitatively determine the fluctuations in temperature and emissivity with wavelength.

[0151]

[0152]

[0153] Where, σ ε and σ T Here, represents the relative mean square error of emissivity and temperature, respectively; m is the number of wavelength groups involved in the calculation; and T is the mean square error of temperature. ave and ε ave These represent the average temperature and average emissivity, respectively. When σ... ε and σ T When the value is less than 5%, the fluctuations in temperature and emissivity with wavelength are considered sufficiently small, and the determined wavelength band belongs to the gray body radiation band. The calibration of the spectral detection system is completed when the determined wavelength band is confirmed to belong to the gray body radiation band. This spectral detection system can be used to detect the flame temperature of burners at multiple target locations in this scheme.

[0154] The distributed control system is used to adjust the primary air hot air damper corresponding to the current eccentric burner under the control of the server, based on the target opening degree of the primary air hot air damper corresponding to the current eccentric burner.

[0155] Optionally, the distributed control system is also used to adjust the primary air cooling dampers corresponding to multiple burners according to the target opening degree of the primary air cooling dampers under the control of the server.

[0156] Optionally, the distributed control system is also used to adjust the opening of the primary air damper according to the target primary air pressure under the control of the server.

[0157] For example, such as Figure 10As shown, the spectral detection system includes a detection device and a spectral analysis device. The detection device can be a flame detection probe. The flame detection probe is positioned above each burner to detect the spectral information of the corresponding burner flame. The flame detection probe transmits the spectral information of the corresponding burner flame to the spectral analysis device via optical fiber. The spectral analysis device contains a spectral analyzer that processes the collected spectral information to obtain the corresponding flame temperature. The spectral analyzer outputs the final flame temperature to the server via a network cable. The server obtains the target opening degrees of the primary air-cooling damper and the primary air-heating damper and inputs them into the distributed control system. Under the control of the server, the distributed control system adjusts the primary air-cooling damper and the primary air-heating damper according to their target opening degrees.

[0158] The specific working process and beneficial effects of the primary air system control system and various optional implementation methods in this embodiment can be referred to the corresponding processes and beneficial effects in the foregoing method embodiments, and will not be repeated here.

[0159] Figure 11 This is a schematic diagram of a primary air system control device provided in this application. This device is suitable for executing the primary air system control method provided in this application, such as... Figure 11 As shown, the device may specifically include:

[0160] The determination module 301 is used to determine the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of the burners at multiple target locations in the current boiler; wherein, the flame temperature is obtained from a spectral detection system, the burners at the multiple target locations are arranged in layers on the current boiler, and the combustion stability index is used to measure the combustion stability of the multiple burners.

[0161] The target distance determination module 302 is used to determine the current target ignition distance of the current off-center burner for each layer based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner.

[0162] The target opening determination module 303 is used to determine the target opening of the primary air and hot air damper corresponding to the current off-center burner for each layer, based on the primary air and hot air optimization model and the current target ignition distance of the current off-center burner; wherein, the primary air and hot air optimization model is used to indicate the mapping relationship between the opening of the primary air and hot air damper corresponding to the burner and the ignition distance.

[0163] The control module 304 is used to control the distributed control system to adjust the primary air hot air damper corresponding to the current eccentric burner according to the target opening degree of the primary air hot air damper corresponding to the current eccentric burner.

[0164] In one embodiment, the plurality of target locations are located on different axes of the furnace of the current boiler;

[0165] The determination module 301 determines the combustion stability indicators of multiple burners based on the flame temperatures of burners at multiple target locations in the current boiler, including:

[0166] Based on the gas phase flow conservation equation in cylindrical coordinates, an axial flow field model of the burner at multiple target locations of the current boiler is constructed.

[0167] The axial flow field model is corrected based on the flame temperature of the burners at multiple target locations of the current boiler to obtain the axial temperature field for each burner; wherein, any point in the axial temperature field corresponds to a temperature value;

[0168] The temperature values ​​of temperature points on the axial temperature field of multiple burners located on the same axis of the furnace at the multiple target locations are obtained respectively.

[0169] For multiple burners on the same axis, the standard deviation of temperature values ​​at temperature points located on the same parallel axis is determined, and the standard deviation of temperature values ​​of multiple burners on the same axis is determined based on the standard deviation of temperature values ​​at temperature points on multiple parallel axes; wherein, the parallel axis is a line parallel to the central axis of the furnace.

[0170] The combustion stability index is determined based on the standard deviation of temperature values ​​of multiple burners on multiple axes.

[0171] In one embodiment, the direction of the axial temperature field is the direction from the burner to a target point on the central axis of the current boiler, wherein the target point is the intersection of the central axis of the current boiler and the central axis of the burner;

[0172] The determining module 301 is used to determine the current off-center burner and the ignition distance of the current off-center burner in each layer based on the flame temperature of the burners at multiple target locations in the current boiler, including:

[0173] In the axial temperature field of each burner, along the direction of the axial temperature field, multiple temperature values ​​corresponding to multiple points on the central axis of the burner are compared with the initial hot air temperature, and the first point corresponding to the temperature value greater than the initial hot air temperature is determined as the ignition point of the burner.

[0174] For each burner, the distance between the ignition point of the burner and the point on the axis of the burner closest to the center of the furnace is taken as the ignition distance of each burner.

[0175] For burners at multiple target locations in each layer, the current off-center burner in that layer is determined based on the ignition distance of the burners at the multiple target locations.

[0176] In one embodiment, the determination module 301, based on the ignition distance of the burners at the plurality of target locations, determines the current off-center burner of the layer, including:

[0177] Based on the variance of the ignition distance of the burners at the multiple target locations, determine whether the current boiler is experiencing uneven burning;

[0178] After determining that the current boiler is experiencing uneven burning, the current uneven burner in the layer is determined based on the deviation between the ignition distance of the plurality of burners and the preset ignition distance.

[0179] In one embodiment, the target distance determination module 302 is specifically used for:

[0180] Based on the characteristics of the current boiler and the preset mapping relationship between boiler characteristics and ignition distance optimization rules, the ignition distance optimization rules for the current boiler are determined.

[0181] The current target ignition distance is determined based on the current ignition distance of the off-center burner, the combustion stability index of the multiple burners, the burner's grinding operation combination, and the current boiler's ignition distance optimization rules.

[0182] In one embodiment, the target opening determination module 303 is specifically used for:

[0183] In the primary air-hot air optimization model, the opening of the primary air-hot air damper is adjusted to obtain the ignition distance output by the primary air-hot air optimization model.

[0184] Determine whether the absolute value of the difference between the ignition distance output by the primary air hot air optimization model and the current target ignition distance is less than a preset distance difference;

[0185] When the absolute value of the difference between the ignition distance output by the primary air hot air optimization model and the current target ignition distance is greater than or equal to the preset distance difference, return to the step of "adjusting the opening of the primary air hot air damper to obtain the ignition distance output by the primary air hot air optimization model";

[0186] When the absolute value of the difference between the ignition distance output by the primary air-hot air optimization model and the current target ignition distance is less than the preset distance difference, the corresponding primary air-hot air damper opening is taken as the target opening of the primary air-hot air damper; wherein, the input of the primary air-hot air optimization model is the coal powder fineness, primary air pressure, primary air flow rate, primary air-hot air flow rate, the temperature of the current off-center burner layer, and the primary air-hot air damper opening, and the output of the primary air-hot air optimization model is the ignition distance.

[0187] In one embodiment, before determining the combustion stability index of multiple burners, the current off-center burner of each layer, and the ignition distance of the current off-center burner based on the flame temperature of the burners at multiple target locations of the current boiler, the determining module 301 is further configured to:

[0188] The spectral detection system is controlled to detect the flames of burners at multiple target locations of the current boiler and obtain the flame temperatures of the burners at multiple target locations of the current boiler; wherein, the flame temperatures of the burners at multiple target locations of the current boiler are calculated by the spectral detection system after detecting the flame spectra of the burners at multiple target locations of the current boiler, and the spectral detection system is a detection system calibrated by gray body radiation band.

[0189] In one embodiment, the device further includes:

[0190] The cold air opening determination module is used to determine the target opening of the primary air cooling damper corresponding to the plurality of burners by using the primary air cooling optimization model and the target mill outlet air-powder mixture temperature; wherein, the primary air cooling optimization model is used to indicate the mapping relationship between the opening of the primary air cooling damper corresponding to the plurality of burners and the mill outlet air-powder mixture temperature.

[0191] The cold air opening adjustment module is used to control the distributed control system to adjust the primary air cooling dampers corresponding to the multiple burners according to the target opening of the primary air cooling dampers.

[0192] In one embodiment, the cold air opening degree determination module is specifically used for:

[0193] In the primary air-cooling optimization model, the opening of the primary air-cooling baffle is adjusted to obtain the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model.

[0194] Determine whether the absolute value of the difference between the mill outlet air-powder mixture temperature output by the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature is less than a preset temperature difference.

[0195] When the absolute value of the difference between the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model and the temperature of the target mill outlet air-powder mixture is greater than or equal to the preset temperature difference, return to the step of "adjusting the opening of the primary air-cooling damper to obtain the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model";

[0196] When the absolute value of the difference between the mill outlet air-powder mixture temperature output by the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature is less than a preset temperature difference, the corresponding primary air-cooling damper opening is taken as the target opening of the primary air-cooling damper corresponding to the plurality of burners; wherein, the input of the primary air-cooling optimization model is pulverized coal fineness, primary air pressure, primary air flow rate, primary air-cooling air flow rate and the primary air-cooling damper opening, and the output of the primary air-cooling optimization model is the mill outlet air-powder mixture temperature.

[0197] In one embodiment, the device further includes:

[0198] The coal feed rate acquisition module is used to acquire the current maximum coal feed rate of the current boiler.

[0199] The primary air pressure determination module is used to determine the target primary air pressure corresponding to the current maximum coal feed rate based on the current maximum coal feed rate of the current boiler and the preset mapping relationship between the maximum coal feed rate and the primary air pressure.

[0200] The primary air damper opening adjustment module is used to control the distributed control system to adjust the primary air damper opening according to the target primary air pressure.

[0201] In one embodiment, before the control module 304 determines the target opening of the primary air hot air damper corresponding to the current off-center burner, it is further configured to:

[0202] When the operating mode is determined to be open-loop operating mode, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is sent to the user;

[0203] When the operating mode is determined to be a closed-loop operating mode, the steps for determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner in the distributed control system are as follows.

[0204] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is merely an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the functional modules described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0205] The apparatus of this application determines the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler. The flame temperature is obtained from a spectral detection system. The burners at the multiple target locations are arranged in layers on the current boiler. The combustion stability index is used to measure the combustion stability of the multiple burners. For each layer of the current off-center burner, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of the multiple burners and the ignition distance of the current off-center burner. For each layer of the current off-center burner, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined through a primary air / hot air optimization model and the current target ignition distance of the current off-center burner. The primary air / hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air / hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air / hot air damper corresponding to the current off-center burner based on the target opening degree of the primary air / hot air damper corresponding to the current off-center burner. The proposed solution, on the one hand, can determine the combustion stability indicators of multiple burners, the current off-center burners on each layer, and the ignition distance of the current off-center burners based on the burner flame temperature, enriching the means of sensing combustion information and providing a data foundation for adjusting the primary air system. On the other hand, it can also determine the target opening degree of the primary air and hot air dampers based on the current target ignition distance and the primary air and hot air optimization model, realizing fine-tuning of the primary air system and providing adjustment data for improving boiler off-center burning, which helps to improve boiler off-center burning. Furthermore, it can control the distributed control system to adjust the primary air and hot air dampers according to the target opening degree, reducing the workload of personnel and ensuring the safe operation of thermal power units.

[0206] This application also provides a computer-readable medium having a computer program stored thereon, which, when executed by a processor, implements the primary air system control method provided in any of the above embodiments.

[0207] The following is for reference. Figure 12 It shows a schematic diagram of the structure of a computer system 400 suitable for implementing the server of this application. Figure 12 The server shown is merely an example and should not impose any limitations on the functionality and scope of this application.

[0208] like Figure 12As shown, the computer system 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes based on programs stored in read-only memory (ROM) 402 or programs loaded from storage section 408 into random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the computer system 400. The CPU 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0209] The following components are connected to I / O interface 405: an input section 406 including a keyboard, mouse, etc.; an output section 407 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to I / O interface 405 as needed. A removable medium 411, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 410 as needed so that computer programs read from it can be installed into storage section 408 as needed.

[0210] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 409, and / or installed from removable medium 411. When the computer program is executed by central processing unit (CPU) 401, it performs the functions defined above in the system of this application.

[0211] It should be noted that the computer-readable medium shown in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0212] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0213] The modules and / or units described in this application can be implemented in software or hardware. The described modules and / or units can also be housed in a processor; for example, a processor can be described as including a determination module, a target distance determination module, a target aperture determination module, and a control module. The names of these modules do not necessarily limit the functionality of the module itself.

[0214] In another aspect, this application also provides a computer-readable medium, which may be included in the device described in the above embodiments; or it may exist alone and not assembled into the device. The computer-readable medium carries one or more programs, which, when executed by the device, cause the device to include:

[0215] Based on the flame temperatures of burners at multiple target locations in the current boiler, the combustion stability indexes of multiple burners, the current off-center burners in each layer, and the ignition distance of the current off-center burners are determined. The flame temperatures are obtained from a spectral detection system. The burners at multiple target locations are arranged in layers on the current boiler. The combustion stability indexes are used to measure the combustion stability of multiple burners. For each layer's current off-center burners, the current target ignition distance of the current off-center burner is determined based on the combustion stability indexes of multiple burners and the ignition distance of the current off-center burner. For each layer's current off-center burners, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined using a primary air / hot air optimization model and the current target ignition distance of the current off-center burner. The primary air / hot air optimization model indicates the mapping relationship between the opening degree of the primary air / hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air / hot air damper corresponding to the current off-center burner based on the target opening degree of the primary air / hot air damper corresponding to the current off-center burner.

[0216] According to the technical solution of this application, based on the flame temperature of burners at multiple target locations in the current boiler, the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner are determined. The flame temperature is obtained from a spectral detection system. The burners at multiple target locations are arranged in layers on the current boiler. The combustion stability index is used to measure the combustion stability of multiple burners. For each layer of current off-center burners, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner. For each layer of current off-center burners, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined through a primary air / hot air optimization model and the current target ignition distance of the current off-center burner. The primary air / hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air / hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air / hot air damper corresponding to the current off-center burner based on the target opening degree of the primary air / hot air damper corresponding to the current off-center burner. The proposed solution, on the one hand, can determine the combustion stability indicators of multiple burners, the current off-center burners on each layer, and the ignition distance of the current off-center burners based on the burner flame temperature, enriching the means of sensing combustion information and providing a data foundation for adjusting the primary air system. On the other hand, it can also determine the target opening degree of the primary air and hot air dampers based on the current target ignition distance and the primary air and hot air optimization model, realizing fine-tuning of the primary air system and providing adjustment data for improving boiler off-center burning, which helps to improve boiler off-center burning. Furthermore, it can control the distributed control system to adjust the primary air and hot air dampers according to the target opening degree, reducing the workload of personnel and ensuring the safe operation of thermal power units.

[0217] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A primary air system control method, characterized in that, The method includes: Based on the flame temperatures of burners at multiple target locations in the current boiler, the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner are determined; wherein, the flame temperature is obtained from a spectral detection system, the burners at multiple target locations are arranged in layers on the current boiler, and the combustion stability index is used to measure the combustion stability of the multiple burners. Specifically, the combustion stability index is used to characterize the calculated standard deviation of the temperature values ​​of burners on different axes of the furnace. The standard deviation of the temperature values ​​is determined based on the standard deviation of the temperature values ​​at temperature points on the axial temperature field of multiple burners on the same parallel axis. The ignition distance of the current off-center burner is determined as follows: the ignition distance is determined based on the distance between the ignition point of the burner and the point on the burner's axis closest to the center of the furnace, where the ignition point is the first point along the axial temperature field direction of the burner where the temperature value is greater than the initial hot air temperature; the current off-center burner for each layer is determined based on the comparison between the variance of the ignition distance of each burner and the preset variance, as well as the deviation value between each ignition distance and the preset ignition distance; the ignition distance corresponding to the current off-center burner is determined as the ignition distance of the current off-center burner. For each layer of the current off-center burner, the current target ignition distance of the current off-center burner is determined based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner. For each layer of the current off-center burner, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is determined by the primary air hot air optimization model and the current target ignition distance of the current off-center burner; wherein, the primary air hot air optimization model is used to indicate the mapping relationship between the opening degree of the primary air hot air damper corresponding to the burner and the ignition distance. The distributed control system adjusts the primary air hot air damper corresponding to the current eccentric burner according to the target opening of the primary air hot air damper corresponding to the current eccentric burner. Specifically, for each layer of the current off-center burner, determining the current target ignition distance of the current off-center burner based on the combustion stability indicators of multiple burners and the ignition distance of the current off-center burner includes: Based on the characteristics of the current boiler and the preset mapping relationship between boiler characteristics and ignition distance optimization rules, the ignition distance optimization rules for the current boiler are determined; based on the ignition distance of the current off-center burner, the combustion stability index of the multiple burners, the grinding operation combination of the burners, and the ignition distance optimization rules for the current boiler, the current target ignition distance is determined. Specifically, for each layer of the current off-center burner, the target opening degree of the primary air / hot air damper corresponding to the current off-center burner is determined using the primary air / hot air optimization model and the current target ignition distance of the current off-center burner, including: In the primary air-heat air optimization model, the opening degree of the primary air-heat air damper is adjusted to obtain the ignition distance output by the primary air-heat air optimization model; it is determined whether the absolute value of the difference between the ignition distance output by the primary air-heat air optimization model and the current target ignition distance is less than a preset distance difference; when the absolute value of the difference between the ignition distance output by the primary air-heat air optimization model and the current target ignition distance is greater than or equal to the preset distance difference, the process returns to "adjust the opening degree of the primary air-heat air damper to obtain the primary air-heat air optimization model". The steps include: 1) determining the ignition distance output by the model; 2) when the absolute value of the difference between the ignition distance output by the primary air / hot air optimization model and the current target ignition distance is less than the preset distance difference, 3) using the corresponding primary air / hot air damper opening as the target opening of the primary air / hot air damper; 4) the inputs to the primary air / hot air optimization model are pulverized coal fineness, primary air pressure, primary air flow rate, primary air / hot air flow rate, the temperature of the current off-center burner layer, and the primary air / hot air damper opening; and 5) the output of the primary air / hot air optimization model is the ignition distance.

2. The method according to claim 1, characterized in that, The multiple target locations are set on different axes of the furnace of the current boiler; The determination of combustion stability indicators for multiple burners based on the flame temperatures of burners at multiple target locations in the current boiler includes: Based on the gas phase flow conservation equation in cylindrical coordinates, an axial flow field model of the burner at multiple target locations of the current boiler is constructed. The axial flow field model is corrected based on the flame temperature of the burners at multiple target locations of the current boiler to obtain the axial temperature field for each burner; wherein, any point in the axial temperature field corresponds to a temperature value; The temperature values ​​of temperature points on the axial temperature field of multiple burners located on the same axis of the furnace at the multiple target locations are obtained respectively. For multiple burners on the same axis, the standard deviation of temperature values ​​at temperature points located on the same parallel axis is determined, and the standard deviation of temperature values ​​of multiple burners on the same axis is determined based on the standard deviation of temperature values ​​at temperature points on multiple parallel axes; wherein, the parallel axis is a line parallel to the central axis of the furnace. The combustion stability index is determined based on the standard deviation of temperature values ​​of multiple burners on multiple axes.

3. The method according to claim 2, characterized in that, The direction of the axial temperature field is the direction from the burner to the target point on the central axis of the current boiler, wherein the target point is the intersection of the central axis of the current boiler and the central axis of the burner; Based on the flame temperature of burners at multiple target locations in the current boiler, determine the current off-center burner in each layer and the ignition distance of the current off-center burner, including: In the axial temperature field of each burner, along the direction of the axial temperature field, multiple temperature values ​​corresponding to multiple points on the central axis of the burner are compared with the initial hot air temperature, and the first point corresponding to the temperature value greater than the initial hot air temperature is determined as the ignition point of the burner. For each burner, the distance between the ignition point of the burner and the point on the axis of the burner closest to the center of the furnace is taken as the ignition distance of each burner. For burners at multiple target locations in each layer, the current off-center burner in that layer is determined based on the ignition distance of the burners at the multiple target locations.

4. The method according to claim 3, characterized in that, Determining the current off-center burner of the layer based on the ignition distance of the burners at the multiple target locations includes: Based on the variance of the ignition distance of the burners at the multiple target locations, determine whether the current boiler is experiencing uneven burning; After determining that the current boiler is experiencing uneven burning, the current uneven burner in the layer is determined based on the deviation between the ignition distance of the plurality of burners and the preset ignition distance.

5. The method according to claim 1, characterized in that, Before determining the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler, the method further includes: The spectral detection system is controlled to detect the flames of burners at multiple target locations of the current boiler and obtain the flame temperatures of the burners at multiple target locations of the current boiler; wherein, the flame temperatures of the burners at multiple target locations of the current boiler are calculated by the spectral detection system after detecting the flame spectra of the burners at multiple target locations of the current boiler, and the spectral detection system is a detection system calibrated by gray body radiation band.

6. The method according to claim 1, characterized in that, The method further includes: The target opening degree of the primary air-cooling damper corresponding to the plurality of burners is determined by using the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature; wherein, the primary air-cooling optimization model is used to indicate the mapping relationship between the opening degree of the primary air-cooling damper corresponding to the plurality of burners and the mill outlet air-powder mixture temperature. The distributed control system adjusts the primary air cooling dampers corresponding to the multiple burners according to the target opening degree of the primary air cooling dampers.

7. The method according to claim 6, characterized in that, The step of determining the target opening degree of the primary air cooling damper corresponding to the multiple burners by using a primary air cooling optimization model and the target mill outlet air-powder mixture temperature includes: In the primary air-cooling optimization model, the opening of the primary air-cooling baffle is adjusted to obtain the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model. Determine whether the absolute value of the difference between the mill outlet air-powder mixture temperature output by the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature is less than a preset temperature difference. When the absolute value of the difference between the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model and the temperature of the target mill outlet air-powder mixture is greater than or equal to the preset temperature difference, return to the step of "adjusting the opening of the primary air-cooling damper to obtain the temperature of the mill outlet air-powder mixture output by the primary air-cooling optimization model"; When the absolute value of the difference between the mill outlet air-powder mixture temperature output by the primary air-cooling optimization model and the target mill outlet air-powder mixture temperature is less than a preset temperature difference, the corresponding primary air-cooling damper opening is taken as the target opening of the primary air-cooling damper corresponding to the plurality of burners; wherein, the input of the primary air-cooling optimization model is pulverized coal fineness, primary air pressure, primary air flow rate, primary air-cooling air flow rate and the primary air-cooling damper opening, and the output of the primary air-cooling optimization model is the mill outlet air-powder mixture temperature.

8. The method according to claim 1, characterized in that, The method further includes: Obtain the current maximum coal feed rate of the current boiler; Based on the current maximum coal feed rate of the boiler and the preset mapping relationship between the maximum coal feed rate and the primary air pressure, the target primary air pressure corresponding to the current maximum coal feed rate is determined. The distributed control system adjusts the opening of the primary air damper according to the target primary air pressure.

9. The method according to claim 1, characterized in that, Before the distributed control system determines the target opening of the primary air hot air damper corresponding to the current off-center burner, the method further includes: When the operating mode is determined to be open-loop operating mode, the target opening degree of the primary air hot air damper corresponding to the current off-center burner is sent to the user; When the operating mode is determined to be a closed-loop operating mode, the steps for determining the target opening degree of the primary air hot air damper corresponding to the current off-center burner in the distributed control system are as follows.

10. A primary air system control system, comprising a server, a spectral detection system, and a distributed control system; wherein, The server is connected to both the spectral detection system and the distributed control system. The server is used to implement the primary air system control method as described in any one of claims 1 to 9; The spectral detection system is used to detect the flame temperature of burners at multiple target locations in the current boiler under the control of the server. The distributed control system is used, under the control of the server, to adjust the primary air hot air damper corresponding to the current off-center burner according to the target opening degree of the primary air hot air damper corresponding to the current off-center burner.

11. The primary air system control system according to claim 10, characterized in that, The spectral detection system is used to collect flame spectra of burners at multiple target locations under the control of the server, and determine the flame temperature based on the wavelength of the flame spectra.

12. A primary air system control device, characterized in that, include: The determination module is used to determine the combustion stability index of multiple burners, the current off-center burner in each layer, and the ignition distance of the current off-center burner based on the flame temperature of burners at multiple target locations in the current boiler. The flame temperature is obtained from a spectral detection system, the burners at the multiple target locations are arranged in layers on the current boiler, and the combustion stability index is used to measure the combustion stability of the multiple burners. Specifically, the combustion stability index is used to characterize the calculated standard deviation of the temperature values ​​of burners on different axes of the furnace. The standard deviation of the temperature values ​​is determined based on the standard deviation of the temperature values ​​at temperature points on the axial temperature field of multiple burners on the same parallel axis. The ignition distance of the current off-center burner is determined as follows: the ignition distance is determined based on the distance between the ignition point of the burner and the point on the burner's axis closest to the center of the furnace, where the ignition point is the first point along the axial temperature field direction of the burner where the temperature value is greater than the initial hot air temperature; the current off-center burner for each layer is determined based on the comparison between the variance of the ignition distance of each burner and the preset variance, as well as the deviation value between each ignition distance and the preset ignition distance; the ignition distance corresponding to the current off-center burner is determined as the ignition distance of the current off-center burner. The target distance determination module is used to determine the current target ignition distance of the current off-center burner for each layer based on the combustion stability index of multiple burners and the ignition distance of the current off-center burner. The target opening determination module is used to determine the target opening of the primary air and hot air damper corresponding to the current off-center burner for each layer, based on the primary air and hot air optimization model and the current target ignition distance of the current off-center burner; wherein, the primary air and hot air optimization model is used to indicate the mapping relationship between the opening of the primary air and hot air damper corresponding to the burner and the ignition distance. The control module is used to control the distributed control system to adjust the primary air hot air damper corresponding to the current eccentric burner according to the target opening degree of the primary air hot air damper corresponding to the current eccentric burner. Specifically, the target distance determination module is used to: determine the current boiler's ignition distance optimization rule based on the characteristics of the current boiler and the preset mapping relationship between boiler characteristics and ignition distance optimization rules; and determine the current target ignition distance based on the ignition distance of the current off-center burner, the combustion stability index of the multiple burners, the burner's grinding operation combination, and the current boiler's ignition distance optimization rule. The target opening determination mold body is used for: adjusting the opening of the primary air / hot air damper in the primary air / hot air optimization model to obtain the ignition distance output by the primary air / hot air optimization model; determining whether the absolute value of the difference between the ignition distance output by the primary air / hot air optimization model and the current target ignition distance is less than a preset distance difference; when the absolute value of the difference between the ignition distance output by the primary air / hot air optimization model and the current target ignition distance is greater than or equal to the preset distance difference, returning to execute "adjusting the opening of the primary air / hot air damper to obtain the ignition distance"; The steps are as follows: "Ignition distance output by the primary air-hot air optimization model"; when the absolute value of the difference between the ignition distance output by the primary air-hot air optimization model and the current target ignition distance is less than the preset distance difference, the corresponding primary air-hot air damper opening is taken as the target opening of the primary air-hot air damper; wherein, the input of the primary air-hot air optimization model is pulverized coal fineness, primary air pressure, primary air flow rate, primary air-hot air flow rate, the temperature of the current off-center burner layer, and the opening of the primary air-hot air damper, and the output of the primary air-hot air optimization model is the ignition distance.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the primary air system control method as described in any one of claims 1 to 9.

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