A method, system and apparatus for in-furnace sootblowing control of a coal-fired furnace

Abstract

The application discloses a coal-fired boiler in-situ soot blowing control method, system and device, a group of temperature measuring cables are arranged around the distribution height of the soot blower on the inner wall of the furnace wall, temperature data at different heights in the furnace is collected, and temperature data of temperature measuring points at different positions on the water cooling wall pipe is acquired. Based on the local temperature data corresponding to different temperature measuring points, it is determined whether the temperature measuring point has soot blowing demand, and the opening instruction of the soot blower corresponding to the temperature measuring point with soot blowing demand is determined. Meanwhile, combined with the current water supply flow, the soot blowing period suitable for the current water cooling wall heat absorption condition is determined, and the control module accurately controls the opening of each soot blower based on the soot blowing period and the soot blowing instruction. Based on this, the accurate control of each soot blower can be realized from the aspects of soot blowing frequency and soot blowing demand, and the overblowing or underblowing of the water cooling wall pipe can be avoided.

Description

Technical Field

[0001] This application relates to the field of boiler soot blowing technology, and more specifically, to a method, system and apparatus for controlling in-furnace soot blowing in a coal-fired boiler. Background Technology

[0002] During operation, the furnace temperature of a coal-fired power plant boiler exceeds 1000℃, and the fly ash components in the flue gas are in a molten and softened state. Highly adhesive ash particles easily adhere to the water-cooled wall tubes, forming slag inside the furnace. This slag formation mainly occurs on the boiler's radiant heating surfaces, creating a slag layer. Due to the low thermal conductivity of this slag layer, the heat transfer resistance on the heating surfaces increases, reducing their heat transfer capacity. These factors lead to deterioration of heat exchange within the furnace, affecting the stability of combustion and posing a threat to the safe operation of the boiler unit.

[0003] Currently, in order to mitigate the negative impact of slag buildup on the water-cooled wall surface in boiler furnaces, large power plant coal-fired boilers are generally equipped with steam short-range telescopic soot blowing devices (hereinafter referred to as short-range soot blowing devices). All short-range soot blowing devices blow the water-cooled wall according to a set cycle. However, excessive blowing can cause water-cooled wall tube damage, wall thinning, and even tube rupture, among other safety issues. Summary of the Invention

[0004] In view of this, this application provides a method, system and apparatus for controlling soot blowing in a coal-fired furnace, which solves the problem that existing soot blowing methods are prone to over-blowing and under-blowing.

[0005] To achieve the above objectives, the following solution is proposed:

[0006] A method for controlling soot blowing inside a coal-fired furnace is applied to a soot blowing command generation module of a soot blowing system inside a coal-fired furnace. The soot blowing system further includes: a data acquisition module for collecting temperature data at temperature measurement points on the soot blowing cables, arranged around a set of temperature measuring cables at the distribution height of the soot blowers on the inner wall of the furnace; and a control module. The soot blowing method inside the coal-fired furnace includes:

[0007] The system acquires the current water flow rate and the temperature data for each soot blower collected by the data acquisition module.

[0008] Based on the pre-established first piecewise function and the preset heat absorption algorithm, the water flow rate is processed respectively to determine the theoretical heat absorption of the water-cooled wall corresponding to the water flow rate and the current actual heat absorption of the water-cooled wall. The first piecewise function is a function used to characterize the characteristic relationship between the water flow rate and the theoretical heat absorption of the water-cooled wall.

[0009] If the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value, the difference between the current time and the time when the soot blower was last turned on is taken as the soot blowing cycle value.

[0010] Based on a pre-established second piecewise function, reference temperature data corresponding to the water flow rate is determined. The second piecewise function is a function used to characterize the relationship between the water flow rate and the reference temperature data of the water-cooled wall.

[0011] Based on the comparison between the temperature data of each sootblower and the reference temperature data, a sootblowing control command is determined, which includes: an opening command or a closing command corresponding to each sootblower;

[0012] The soot blowing cycle value and the soot blowing control command are sent to the control module, so that the control module takes the current time as the starting point and controls each soot blower to turn on or off according to the soot blowing control command when the accumulated time reaches the soot blowing cycle value.

[0013] Optionally, determining the soot blowing control command based on the comparison result between the temperature data of each of the soot blowers and the reference temperature data includes:

[0014] For each of the soot blowers, the following steps are performed based on the temperature data:

[0015] Determine whether the temperature data is lower than the reference temperature data;

[0016] If the temperature data is lower than the reference temperature data, a start command for the soot blower is determined.

[0017] If the temperature data is not less than the reference temperature data, a shutdown command corresponding to the soot blower is determined;

[0018] Based on the opening or closing command corresponding to each of the soot blowers, a soot blowing control command is determined.

[0019] Optionally, the step of acquiring the temperature data corresponding to each sootblower collected by the data acquisition module at the current moment includes:

[0020] The data acquisition module acquires the first initial temperature data and the second initial temperature data of each preset temperature measurement point on both sides of the soot blower. The first initial temperature data and the second initial temperature data are temperature data within a preset time period including the current moment.

[0021] For each of the soot blowers and the corresponding first initial temperature data and second initial temperature data, the following steps are performed:

[0022] The first initial temperature data and the second initial temperature data are respectively subjected to noise reduction processing to obtain the first noise-reduced temperature data corresponding to the first initial temperature data and the second noise-reduced temperature data corresponding to the second initial temperature data.

[0023] Determine the first data change trend of the first noise reduction temperature data and the second data change trend of the second noise reduction temperature data;

[0024] Determine whether the trend of change of the first data and the trend of change of the second data are consistent with the preset trend of change of data;

[0025] If the first data change trend and the second data change trend are consistent with the preset data change trend, the temperature data corresponding to the soot blower at the current moment is determined based on either the first noise reduction temperature data or the second noise reduction temperature data.

[0026] If the first data change trend is consistent with the preset data change trend, and the second data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the first noise reduction temperature data.

[0027] If the second data change trend is consistent with the preset data change trend, and the first data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the second noise reduction temperature data.

[0028] Optionally, the process of pre-establishing the first piecewise function includes:

[0029] Acquire sample data of heat absorption of the water-cooled wall of the coal-fired boiler within a preset load range, and sample data of water flow rate corresponding to each sample data of heat absorption;

[0030] Based on the heat absorption sample data and water flow rate sample data of each group of water-cooled walls that have a corresponding relationship, a heat absorption curve is determined with the water flow rate sample data as the independent variable and the heat absorption sample data as the dependent variable.

[0031] Based on the heat absorption curve, mean filtering is performed on each of the water flow rate sample data to obtain the theoretical heat absorption corresponding to each of the water flow rate sample data.

[0032] Based on each water flow rate sample data and the theoretical heat absorption corresponding to each water flow rate sample data, a relationship function between the water flow rate sample data and the theoretical heat absorption is determined, and the relationship function is determined as the first piecewise function.

[0033] Optionally, the process of pre-establishing the second piecewise function includes...

[0034] The temperature sample data collected by the data acquisition module of the coal-fired boiler within the preset load range, and the water flow sample data at the corresponding time of each temperature data are obtained.

[0035] Based on each set of temperature sample data and water flow sample data that have a corresponding relationship, a temperature curve is determined with the water flow sample data as the independent variable and the temperature sample data as the dependent variable.

[0036] Based on the temperature curve, mean filtering is performed on the temperature sample data corresponding to each water flow rate sample data to obtain the reference temperature data corresponding to each water flow rate sample data.

[0037] Based on each water flow rate sample data and the corresponding reference temperature data, a relationship function between the water flow rate sample data and the reference temperature data is determined, and the relationship function is defined as a first piecewise function.

[0038] Optionally, the process of obtaining the preset threshold value includes:

[0039] Obtain the actual heat absorption of the water-cooled wall of the coal-fired boiler within a preset time range and the theoretical heat absorption corresponding to the actual heat absorption;

[0040] Based on the difference between the actual heat absorption within the preset time range and the theoretical heat absorption corresponding to the actual heat absorption, difference sample data is determined;

[0041] From the difference sample data, determine the maximum and minimum differences;

[0042] Based on the historical data of soot blowing of the coal-fired boiler, the average soot blowing cycle and the maximum soot blowing cycle are determined;

[0043] The initial preset parameter value is determined by adjusting the relationship coefficient of the function between the maximum difference and the minimum difference;

[0044] Based on the initial preset parameter values, determine the actual soot blowing cycle corresponding to the preset heat absorption difference;

[0045] Determine whether the difference between the soot blowing cycle and the average value of the soot blowing cycle meets a preset threshold.

[0046] When the difference between the soot blowing cycle and the average value of the soot blowing cycle does not meet the preset threshold, the step of determining the initial preset parameter value by adjusting the relationship coefficient between the preset parameter value and the maximum difference and the minimum difference is executed until the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold.

[0047] When the difference between the soot blowing cycle and the average value of the soot blowing cycle meets a preset threshold, a preset critical value is determined based on the relationship coefficient at the current moment and the relationship function between the maximum difference and the minimum difference.

[0048] Optional, also includes:

[0049] The difference between the current time and the time when the soot blower was last turned on is determined as the initial soot blowing cycle value;

[0050] Determine whether the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value;

[0051] When the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value, the initial soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower.

[0052] When the initial soot blowing cycle value is greater than the maximum soot blowing cycle value, the maximum soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower;

[0053] When the initial soot blowing cycle value is less than the average soot blowing cycle value, the average soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower.

[0054] Optional, also includes:

[0055] The steam pressure value of the steam supply main and the condensate temperature value of the condensate drain main are obtained from the monitoring device.

[0056] When the steam supply pressure reaches the first set value and the condensate temperature reaches the second set value, it is determined that the soot blowing steam currently used for soot blowing meets the soot blowing conditions.

[0057] The identification information indicating that the soot blowing steam currently used for soot blowing meets the soot blowing conditions is sent to the control module, so that the control module takes the current time as the starting point and, when the accumulated time reaches the soot blowing cycle value, controls the opening or closing of each soot blower according to the soot blowing control command corresponding to each soot blower and the identification information.

[0058] A coal-fired furnace soot blowing control system is applied to a coal-fired furnace, the coal-fired furnace including at least a furnace wall, a water-cooled wall, and a plurality of soot blowers installed on the furnace wall. The soot blowers are distributed at different heights on the furnace wall. The coal-fired furnace soot blowing control system includes: a set of temperature measuring cables arranged around the inner wall of the furnace wall at the heights corresponding to the distribution of the soot blowers. The temperature measuring cables are used to detect temperature data at each preset temperature measuring point set on the temperature measuring cables.

[0059] A data acquisition module set at a preset temperature measurement point is used to collect the temperature data of the temperature measuring cable at the temperature measurement point;

[0060] A soot blowing instruction generation module is used to execute any one of the soot blowing control methods for coal-fired furnaces.

[0061] The control module is used to receive the soot blowing control command and the soot blowing cycle value sent by the soot blowing command generation module, and, taking the current time as the starting point, respond to the soot blowing control command when the accumulated time reaches the soot blowing cycle value, control the opening or closing of each soot blower.

[0062] Optionally, it also includes: monitors respectively installed at the outlet of the steam supply main pipe and the outlet of the drain main pipe, for monitoring the steam supply pressure value of the steam supply main pipe and the drain temperature value of the drain main pipe, wherein the steam supply main pipe and the drain main pipe are connected to the soot blower to provide soot blowing steam to the soot blower.

[0063] A coal-fired furnace in-furnace soot blowing control device is applied to the soot blowing command generation module of the coal-fired furnace in-furnace soot blowing system. The coal-fired furnace in-furnace soot blowing device includes:

[0064] The data acquisition unit is used to acquire the current water flow rate and the temperature data of each soot blower collected by the data acquisition module.

[0065] The heat absorption determination unit is used to process the water supply flow rate based on a pre-established first piecewise function and a preset heat absorption algorithm, and to determine the theoretical heat absorption of the water-cooled wall corresponding to the water supply flow rate and the current actual heat absorption of the water-cooled wall. The first piecewise function is used to characterize the characteristic relationship between the water supply flow rate and the theoretical heat absorption of the water-cooled wall.

[0066] The soot blowing cycle value determination unit is used to determine the soot blowing cycle value by taking the difference between the current time and the time when the soot blower was last turned on when the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value.

[0067] The reference temperature data determination unit is used to determine the reference temperature data corresponding to the water flow rate according to a pre-established second piecewise function, wherein the second piecewise function is used to characterize the characteristic relationship between the water flow rate and the temperature data of the water-cooled wall;

[0068] The instruction determination unit is used to determine a soot blowing control instruction based on the comparison result between the temperature data of each soot blower and the reference temperature data. The soot blowing control instruction includes: an opening instruction or a closing instruction corresponding to each soot blower.

[0069] The instruction issuing unit is used to send the soot blowing cycle value and the soot blowing control instruction to the control module, so that the control module, with the current time as the starting point, controls the opening or closing of each soot blower according to the soot blowing control instruction when the accumulated time reaches the soot blowing cycle value.

[0070] This application involves installing a set of temperature measuring cables around the distribution height of the sootblowers on the inner wall of the furnace to collect temperature data at different heights within the furnace. This facilitates the acquisition of temperature data from measuring points at different locations on the water-cooled wall tubes. Based on the local temperature data corresponding to different measuring points, it is determined whether there is a need for soot blowing at that point, thereby determining the activation command for the sootblower corresponding to the measuring point with soot blowing needs. Simultaneously, combined with the current feedwater flow rate, a soot blowing cycle suitable for the current heat absorption of the water-cooled wall is determined. The control module accurately controls the activation of each sootblower based on the soot blowing cycle and the soot blowing command. This application achieves precise control of each sootblower from both the perspectives of soot blowing frequency and soot blowing needs. Each sootblower is activated as needed, and the soot blowing cycle is adjusted in real time, which can precisely control the slag-cleaning effect of each sootblower on localized slag buildup in the furnace, avoiding over-blowing or under-blowing of the water-cooled wall tubes. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0072] Figure 1 A schematic diagram of a water-cooled wall tube structure provided in an embodiment of this application;

[0073] Figure 2 This application provides an optional system architecture diagram for an in-furnace soot blowing control system provided in an embodiment of the present application.

[0074] Figure 3This is a schematic diagram of an optional process for implementing an in-furnace soot blowing control method for a coal-fired furnace, as provided in an embodiment of this application.

[0075] Figure 4 This is a schematic diagram of an optional structure of the coal-fired furnace soot blowing control device provided in the embodiments of this application. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0077] The boiler structure mainly consists of two parts: the boiler body and auxiliary equipment. The boiler body may include: a combustion system, a steam-water system, furnace walls, and a frame. The combustion system includes the furnace, flue, burners, etc., for burning fuel in the furnace and releasing heat; the steam-water system includes water-cooled walls, economizers, superheaters, etc., for effectively absorbing the heat released by fuel combustion; and the furnace walls form a closed furnace and flue, while the frame supports or fixes the various components inside the boiler.

[0078] Reference Figure 1 This application provides a schematic diagram of a water-cooled wall tube structure. The water-cooled wall is the main evaporative heating surface of the boiler, arranged around the inside of the boiler, and consists of multiple water-cooled wall tubes. The flowing medium inside the tubes is generally water or a steam-water mixture. The water-cooled wall can absorb the heat released by fuel combustion in the furnace and cool the flue gas to the temperature allowed at the furnace outlet. Based on this, it can also reduce slagging in the furnace and prevent slagging at the furnace outlet.

[0079] However, the fly ash from fuel combustion can easily accumulate on the surface of the water-cooled wall, forming slag inside the furnace. This can reduce the heat absorption capacity of the water-cooled wall and increase the flue gas temperature at the furnace outlet. Therefore, it is necessary to clean and maintain the surface of the water-cooled wall regularly.

[0080] Currently, power plants commonly use a set frequency soot blowing method, which has economic and safety problems such as poor soot blowing economy and easy damage and bursting of pipes. Based on this, the embodiments of this application propose an in-furnace soot blowing control system for coal-fired furnaces.

[0081] Reference Figure 2This application provides an optional system architecture diagram for a coal-fired furnace soot blowing control system. The control system is applied to a coal-fired furnace, which includes at least a furnace wall, a water-cooled wall, and multiple soot blowers installed on the furnace wall at different heights. As shown in the figure, the coal-fired furnace soot blowing control system may include: a temperature measuring cable, a data acquisition module, a soot blowing command generation module, and a control module.

[0082] A set of temperature measuring cables is arranged around the inner wall of the furnace at the height corresponding to the distribution of the soot blowers. The temperature measuring cables are used to detect the temperature data at each preset temperature measuring point on the temperature measuring cables. A data acquisition module is set at the preset temperature measuring point to collect the temperature data of the temperature measuring cable at the temperature measuring point.

[0083] like Figure 2 The rectangle enclosed by solid black lines represents the furnace chamber, and the solid black lines also represent the furnace walls, on which water-cooled wall tubes are distributed. The dashed black lines represent temperature sensing cables, which are specifically installed at the back-fire side fins of the water-cooled walls, such as... Figure 1 The location of the fins in the diagram. It's understood that while the temperature sensing cable is shown as a dashed line in the schematic, it is actually installed as a solid line. The dashed line in the example diagram is only used to distinguish it from the furnace wall. Optionally, when installing the temperature sensing cable, the blowing radius of the sootblower installed in the furnace can be determined in advance. The temperature sensing cable should be installed within the blowing range, approximately at half the blowing radius, and at least one temperature measuring point should be set next to each sootblower.

[0084] It is understandable that temperature measuring points, or temperature sensing points, are used to collect temperature information and convert it into electrical signals. The closer the temperature measuring point is to the sootblower, the more accurately the collected temperature information reflects the temperature environment of the sootblower. Therefore, the temperature measuring points are set as close to the sootblower as possible without affecting its normal blowing operation. However, because even when the temperature measuring points are set as close to the sootblower as possible, the distance between each measuring point and the sootblower varies, the temperature data obtained by the sootblowing command generation module for each measuring point does not have a unified standard. Even if the data is accurate, it cannot be determined whether the temperature data reflects the temperature of the sootblower within a preset range. Therefore, this embodiment can also set a preset distance, setting at least one temperature measuring point within the preset distance range.

[0085] In this embodiment, the installation location and quantity of the temperature measuring cables are determined based on the various soot blowers distributed on the furnace wall. Taking a 350MW supercritical unit as an example, there are 16 soot blowers at the same height in the furnace, and the temperature measuring cables are arranged around the furnace. At other furnace heights where soot blowers are located, temperature measuring cables are also arranged around the furnace at that height. Furthermore, the arrangement of the cables around the furnace in this embodiment is not limited to using a single temperature measuring cable; it can also involve a half-circle arrangement or a combination of temperature measuring cables of different lengths. Specifically, the operator can determine whether a group of temperature measuring cables consists of one, two, or even more cables based on the internal environment of the furnace, the remaining length of the temperature measuring cables, and the number of temperature measuring points.

[0086] Understandably, assuming a single temperature sensing cable can be set up with 30 temperature sensing points (or measurement points), and there are 31 sootblowers at the same height, requiring at least one temperature measurement point next to each sootblower, then 30 measurement points would be insufficient to measure the temperature of all 31 sootblowers. Therefore, two temperature sensing cables would be needed. Data collection for each measurement point can be achieved by setting up a data acquisition module at each point to collect the temperature data and transmit it to the sootblowing command generation module via a twisted-pair shielded cable.

[0087] Optionally, to avoid the inability to guarantee timely detection of abnormalities when there is a problem with the temperature measuring cable or the temperature measuring point due to a single temperature measuring point, this embodiment of the application sets a temperature measuring point on both sides of each sootblower. In this way, after receiving two temperature data from the same sootblower, the sootblowing instruction generation module compares them to see if there is a measurement difference. If the difference is within a reasonable range, it proves that the measurement is not abnormal. If the difference is not within a reasonable range, it may be necessary to remeasure or replace the temperature measuring cable, etc.

[0088] In the embodiments of this application, there are various types of temperature measuring cables available for selection, but the selected temperature measuring cable needs to be able to be used during normal combustion in the furnace. For example, the operating temperature range of the temperature measuring cable can be maintained between 0℃ and 550℃, and the measurement range can be between 0℃ and 550℃.

[0089] The soot blowing command generation module can acquire relevant parameters of the boiler furnace and temperature data acquired by the aforementioned data acquisition module, generate soot blowing control commands and soot blowing cycles based on these parameters, and send the soot blowing control commands and soot blowing cycles to the control module.

[0090] Upon receiving the sootblowing control command and the sootblowing cycle, the control module controls each sootblower installed on the furnace wall. It is understood that the sootblowing cycle limits the frequency of sootblowing, and the sootblowing control command limits the opening or closing command for each sootblower. Therefore, the control module uses the moment it receives the sootblowing control command and the sootblowing cycle as the starting point for timing. When the accumulated time reaches the sootblowing cycle value, the control module opens or closes each sootblower according to the sootblowing control command.

[0091] The control module can be an independently set control module or a DCS (Distributed Control System). The DCS system can extract relevant parameters of the boiler furnace, such as feedwater flow rate, unit load, economizer outlet water temperature, and sootblower action signals (such as retraction position or operating status signals). The sootblowing command generation module can be an industrial computer, located in the power plant's electronics room or engineering workstation, and can achieve bidirectional communication with the control module. The temperature data collected by the data acquisition module can be transmitted to the sootblowing command generation module through the control module, while simultaneously acquiring relevant furnace data such as feedwater flow rate collected from the control module for processing, determining the sootblowing cycle and the sootblowing command for each sootblower.

[0092] Compared to existing technologies, this method can collect local environmental information such as temperature and heat exchange of each sootblower, and based on the local environmental information, the sootblowing cycle and sootblowing command for each sootblower can be determined in the sootblowing command generation module, so that the sootblower can be turned on as needed, reducing the occurrence of overblowing and underblowing.

[0093] Reference Figure 3 This application provides an optional flowchart illustrating a method for controlling soot blowing inside a coal-fired furnace. The method is applied to the soot blowing command generation module of the aforementioned coal-fired furnace soot blowing control system. The specific process may include:

[0094] Step S110: Obtain the current water flow rate and the temperature data corresponding to each soot blower collected by the data acquisition module.

[0095] The feedwater flow rate refers to the flow rate of water entering the boiler, which can be measured by a flow meter installed on the boiler inlet and outlet pipes. The measurement results of the feedwater flow rate can be obtained from modules such as the measuring device and the DCS system.

[0096] It is understood that the temperature data acquired by the data acquisition module is the temperature information detected by the temperature measuring cable that can characterize the temperature. The data information is usually a waveform electrical signal. The waveform electrical signal can be processed by the data acquisition module to obtain the temperature data in numerical form, or the waveform electrical signal can be transmitted to the controller or the soot blowing command generation module and other functional modules for signal processing. There are a variety of signal processing methods available, and this application embodiment does not make any special limitation on them.

[0097] Based on the above description, in order to improve the accuracy of temperature data detection of the sootblower, this embodiment of the application sets a temperature measuring point on each side of the sootblower, and configures a data acquisition module for each temperature measuring point. The data acquisition module transmits the temperature data of the corresponding temperature measuring point to the sootblowing command generation module. The sootblowing command generation module filters from the temperature data to determine the more accurate temperature data for subsequent sootblowing cycle or sootblowing command calculation.

[0098] Optionally, the process of processing the temperature data acquired by the data acquisition module includes: acquiring the first initial temperature data and the second initial temperature data of each preset temperature measurement point on both sides of the sootblower acquired by the data acquisition module, wherein the first initial temperature data and the second initial temperature data are temperature data within a preset time period including the current time.

[0099] For each of the soot blowers and the corresponding first initial temperature data and second initial temperature data, the following steps are performed:

[0100] The first initial temperature data and the second initial temperature data are respectively subjected to noise reduction processing to obtain the first noise-reduced temperature data corresponding to the first initial temperature data and the second noise-reduced temperature data corresponding to the second initial temperature data; the first data change trend of the first noise-reduced temperature data and the second data change trend of the second noise-reduced temperature data are determined; and it is determined whether the first data change trend and the second data change trend are consistent with the preset data change trend.

[0101] If the first data change trend and the second data change trend are consistent with the preset data change trend, the temperature data corresponding to the soot blower at the current moment is determined based on either the first noise reduction temperature data or the second noise reduction temperature data.

[0102] If the first data change trend is consistent with the preset data change trend, and the second data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the first noise reduction temperature data; if the second data change trend is consistent with the preset data change trend, and the first data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the second noise reduction temperature data.

[0103] In this embodiment, the temperature data on both sides of the sootblower are recorded as: first initial temperature data and second initial temperature data. Since the processing procedure for the temperature data on both sides of each sootblower is the same, the following description will take the processing procedure for the first initial temperature data and second initial temperature data of any one of the sootblowers as an example.

[0104] It is understandable that during the process of the data acquisition module extracting temperature data from the temperature measurement cable and transmitting the temperature data, noise is present due to environmental and instrumental factors. Therefore, noise reduction processing is required for both the first and second initial temperature data. The power industry employs various commonly used noise reduction methods, such as amplitude limiting filtering, median filtering, arithmetic mean filtering, median average filtering, and first-order hysteresis filtering. The appropriate and most effective noise reduction method can be selected based on the actual noise conditions to reduce noise in both the first and second initial temperature data. This application does not limit the use of a single noise reduction method.

[0105] Optionally, this application uses a wavelet threshold denoising algorithm that has no noise reduction delay and can retain high-frequency signals while removing low-frequency signals as an example to illustrate the denoising of the first initial temperature data. The one-dimensional signal model containing noise is shown in the following equation (1):

[0106] f(t)=s(t)+n(t).............(1)

[0107] In the formula, s(t) represents the original signal, i.e., the first initial temperature data; n(t) is the variance σ. 2 Gaussian white noise, obeying N(0,σ) 2 ).

[0108] First, a wavelet coefficient threshold can be set to distinguish the magnitude of noise in the initial temperature data. Signals greater than the wavelet coefficient threshold are extracted and retained, while noise less than the threshold is discarded or filtered out. Based on this, the first denoised temperature data is obtained. In practical engineering, the wavelet coefficient threshold can be adjusted according to the actual situation to ensure that the denoised temperature data is more accurate.

[0109] After noise reduction, it is necessary to further compare the temperature data on both sides of the sootblower. Optionally, in this embodiment of the application, the temperature data change trends of the first noise reduction temperature data and the second noise reduction temperature data are compared within a preset time period. Under normal measurement conditions, the data change trends of the two are consistent and consistent with the preset data change trend. At this time, either the first noise reduction temperature data or the second noise reduction temperature data can be selected to determine the temperature data of the sootblower at the current moment.

[0110] If only one of the first and second data change trends matches the preset data change trend, the noise reduction temperature data that matches the preset data change trend is selected to determine the current temperature data of the sootblower. Similarly, if neither the first nor the second data change trend matches the preset data change trend, the sootblowing command generation module can feed this information back to the control module or control terminal so that engineers can be aware of any abnormalities in the furnace equipment in a timely manner. The preset temperature change trend can be determined in advance based on the temperature data of the sootblower from a previous period.

[0111] It is understandable that each moment in the preset time period in the first or second noise reduction temperature data corresponds to a temperature value or temperature data. Therefore, the temperature data of the sootblower at the current moment can be determined based on the noise reduction temperature data corresponding to the current moment. For example, the first initial temperature data is [t0, t1, t2, ..., t n ], where t0 represents the temperature value or temperature data at the start time of the preset time period, t n The temperature value or temperature data refers to the end time of the preset time period, i.e., the current time. The meanings of other data such as t1 and t2 can be deduced similarly and will not be elaborated here. The first denoised temperature data obtained after denoising the first initial temperature data is [t0]. w ,t1 w ,t2 w ,……,t n w [The t value can be taken from the first noise reduction temperature data.] n w This represents the temperature data corresponding to the soot blower at the current moment.

[0112] Based on the above, the way the soot blowing instruction generation module obtains the temperature data of the soot blower can determine more accurate and reliable temperature data, and at the same time improve the self-testing capability of the hardware temperature data acquisition and transmission equipment.

[0113] Step S120: Based on the pre-established first piecewise function and the preset heat absorption algorithm, the water flow rate is processed to determine the theoretical heat absorption of the water-cooled wall corresponding to the water flow rate and the current actual heat absorption of the water-cooled wall.

[0114] The first piecewise function is used to characterize the relationship between the water flow rate and the heat absorption of the water-cooled wall. The preset heat absorption algorithm can select a more accurate algorithm from existing heat absorption algorithms to calculate the actual heat absorption of the water-cooled wall at any given time. In this embodiment, the overall heat absorption of the water-cooled wall at the current time is calculated based on the following formula (2) to determine the actual heat absorption of the water-cooled wall at the current time.

[0115]

[0116] In the formula, Q represents the heat absorbed per unit amount of fuel; H out The enthalpy of the steam at the water-cooled wall outlet is given. For supercritical units, the enthalpy of the superheated steam can be obtained by consulting the steam property parameter table based on the outlet pressure and temperature of the steam-water separator. For subcritical units, the enthalpy of the wet saturated steam can be obtained by consulting the steam property parameter table based on the steam drum pressure. The enthalpy of the steam at the water-cooled wall inlet is given. This enthalpy can be obtained by consulting the steam property parameter table based on the economizer outlet water temperature and pressure. The feedwater flow rate is given. If the feedwater flow rate cannot be obtained, the main steam flow rate can be used instead. The calculated fuel consumption is given, which can be obtained in real time through the DCS system.

[0117] The actual heat absorption of the water-cooled wall obtained based on equation (2) can reflect the overall degree of fouling of the water-cooled wall. However, this parameter will fluctuate with the unit load. Therefore, it is necessary to reduce the impact of the unit load and amplify the impact of ash accumulation (or furnace clogging). In this embodiment, the heat absorption of the water-cooled wall under the corresponding unit load (referred to as theoretical heat absorption in this embodiment) can be determined based on historical data. The feedwater flow rate is used to represent the change of the unit load. A large amount of heat absorption of the water-cooled wall under different unit loads is obtained for analysis. After normalization, the corresponding relationship function between the unit load (or feedwater flow rate) and the heat absorption of the water-cooled wall is determined, namely the first piecewise function.

[0118] Optionally, the process of establishing the first piecewise function in this application embodiment may include: acquiring sample data of the heat absorption of the water-cooled wall of the coal-fired boiler within a preset load range, and sample data of the feedwater flow rate corresponding to each sample data of the heat absorption; determining a heat absorption curve with the feedwater flow rate sample data as the independent variable and the heat absorption sample data as the dependent variable based on each set of corresponding sample data of the water-cooled wall; traversing each sample data of the feedwater flow rate in the heat absorption curve, and performing the following steps for each sample data of the feedwater flow rate. Using the water flow rate sample data as an anchor point, and based on a preset filtering interval parameter, a water flow rate interval with the anchor point as the interval center is determined. The mean of all heat absorption sample data corresponding to the water flow rate interval is calculated, and the result of the mean calculation is determined as the theoretical heat absorption of the water flow rate sample data corresponding to the anchor point. Based on each water flow rate sample data and the theoretical heat absorption corresponding to each water flow rate sample data, a relationship function between the water flow rate sample data and the theoretical heat absorption is determined, and the relationship function is determined as a first piecewise function.

[0119] First, collect sample data of heat absorption of the water-cooled wall and sample data of water flow rate at the time corresponding to the sample data of heat absorption of the water-cooled wall. The time corresponding to the collected data does not need to be continuous, but the collected data needs to include the data of the unit within the preset load range (such as 50%-100%).

[0120] Optionally, the collected sample data can be sorted from smallest to largest based on the water flow rate, and the water-cooled wall heat absorption sample data can also be changed according to the sorting of the corresponding water flow rate sample data, so as to obtain a curve with the water flow rate sample data as the x-axis and the water-cooled wall heat absorption as the y-axis, i.e. the heat absorption curve mentioned above.

[0121] Furthermore, mean filtering is applied to the water-cooled wall heat absorption sample data in the curve graph, with a fixed filtering interval [am, a+m], where 'a' represents any feedwater flow rate sample data in the curve graph, and 'm' is a set value. The mean of the water-cooled wall heat absorption sample data corresponding to all feedwater flow rate sample data within this filtering interval is calculated, and the resulting mean water-cooled wall heat absorption is used as the theoretical heat absorption at the interval center point 'a'. Based on this, each feedwater flow rate sample data in the curve graph is traversed, and filtering calculations are performed using each feedwater flow rate sample data as the center point of the filtering interval to obtain the theoretical heat absorption corresponding to each feedwater flow rate sample data in the curve graph.

[0122] Based on the theoretical heat absorption corresponding to each of the aforementioned water flow rate sample data, the relationship between the theoretical heat absorption of the water-cooled wall, the mean filtering parameters, and the water flow rate is obtained, as expressed by the following equation (3):

[0123]

[0124] In equation (3), a represents the water supply flow rate, m represents the interval parameter of the mean filter, n represents the maximum water supply flow rate, and Q' a This represents the theoretical heat absorption of the water-cooled wall after normalization, corresponding to the water flow rate 'a'.

[0125] Furthermore, based on the above equation (3), the one-to-one correspondence between the water flow rate and the heat absorption of the water-cooled wall is obtained, and a piecewise function of the water flow rate and the overall heat absorption of the water-cooled wall after standardization is established, namely the first piecewise function, as shown in equation (4).

[0126]

[0127] In equation (4), amin is the minimum water supply flow rate in the above water supply flow rate sample data, amax is the maximum water supply flow rate in the above water supply flow rate sample data, i represents the real-time value of the water supply flow rate, and Q amin 'This is the sample data of heat absorption of the water-cooled wall corresponding to the minimum feedwater flow rate, Q' amax 'a' represents the sample data of heat absorption of the water-cooled wall corresponding to the maximum water supply flow rate. i-1 a is the smaller water flow rate value adjacent to the real-time water flow rate value in the above water flow rate sample data. i+1 Q is the larger water flow rate value adjacent to the real-time water flow rate value in the above water flow rate sample data. ai-1 'For the water supply flow rate a i-1 The corresponding heat absorbed by the water-cooled wall, Q ai+1 'For the water supply flow rate a i+1 The corresponding water-cooled wall absorbs heat.

[0128] As can be seen from the above, the standardized heat absorption of the water-cooled wall calculated by substituting the current water flow rate into equation (4) is used as the theoretical heat absorption, reflecting the average level of heat absorption under the current unit load. If the difference between the actual heat absorption and the theoretical heat absorption is less than the preset critical value, it can be proven that the slagging of the water-cooled wall is quite serious, which has seriously affected the heat absorption capacity of the water-cooled wall, and soot blowing is required. Further, step S130, i.e., the subsequent steps, is executed to achieve soot blowing.

[0129] Step S130: If the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value, the difference between the current time and the time when the soot blower was last turned on is taken as the soot blowing cycle value.

[0130] Based on the above description, under the influence of slagging in the furnace, if the difference in heat absorption of the water-cooled wall is lower than the limit, it indicates that the slagging has a significant adverse effect on the heat absorption capacity of the water-cooled wall, requiring more frequent soot blowing. Conversely, if the difference in heat absorption of the water-cooled wall is higher than the limit, it indicates that the current heat absorption capacity of the water-cooled wall is within the normal range, and the frequency of purging the slagging in the furnace needs to be reduced to avoid over-blowing.

[0131] Optionally, in this embodiment, a preset threshold value is used to determine what adjustments need to be made to the current soot blowing cycle and to determine the soot blowing cycle. The actual heat absorption Q of the water-cooled wall at the current moment is then used. c and theoretical heat absorption Q a By subtracting the values, we obtain the difference in heat absorption: delta_Q = Q c -Q a The heat absorption difference delta_Q is compared with a preset critical value delta_Q_limit. When delta_Q is less than delta_Q_limit, the soot blowing instruction generation module sends a soot blowing reminder to the control module or the control terminal used by the engineer to receive information. The soot blowing reminder may include the soot blowing cycle and warning information.

[0132] The soot blowing cycle is the time difference between the current moment and the last soot blowing moment, and the soot blowing cycle is calculated using the following formula (5):

[0133] P(delta_Q) = TIME B -TIME0...............(5)

[0134] In equation (5), P(delata_Q) represents the soot blowing cycle, and TIME B TIME0 represents the moment when delta_Q < delta_Q_limit, and TIME0 represents the moment when the sootblower last blew soot.

[0135] The preset critical value can be set by the engineer based on past boiler operation experience to determine a heat absorption value as the preset critical value, or by statistically analyzing the difference in heat absorption of the boiler under different degrees of slagging in the furnace to determine a critical value, so as to distinguish the degree of slagging in the furnace that requires purging by the difference in heat absorption.

[0136] Optionally, the method for determining the preset critical value in this application embodiment may include: obtaining the actual heat absorption of the water-cooled wall of the coal-fired boiler within a preset time range and the theoretical heat absorption corresponding to the actual heat absorption; determining difference sample data based on the difference between the actual heat absorption within the preset time range and the theoretical heat absorption corresponding to the actual heat absorption; determining the maximum difference and the minimum difference from the difference sample data; determining the average value and the maximum value of the soot blowing cycle based on the soot blowing history data of the coal-fired boiler; determining an initial preset parameter value by adjusting the relationship coefficient of the relationship function between the maximum difference and the minimum difference; determining the actual soot blowing cycle corresponding to the preset heat absorption difference based on the initial preset parameter value; and determining whether the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold.

[0137] When the difference between the soot blowing cycle and the average value of the soot blowing cycle does not meet the preset threshold, the step of determining the initial preset parameter value by adjusting the relationship coefficient between the preset parameter value and the maximum difference and the minimum difference is executed until the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold; when the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold, a preset critical value is determined based on the relationship coefficient at the current time and the relationship function between the maximum difference and the minimum difference.

[0138] The preset time range refers to any historical time period before the current moment. In this embodiment, historical data is used to determine the preset threshold. The theoretical heat absorption and actual heat absorption corresponding to different historical moments are obtained to determine the difference between the theoretical heat absorption and actual heat absorption corresponding to different historical moments, and the difference corresponding to each historical moment is determined as the difference sample data.

[0139] The relationship between the maximum difference delta_Q_max, the minimum difference delta_Q_min, and the preset critical value delta_Q_limit in the difference sample data can be found in the following equation (6):

[0140] delta_Q_limit=delta_Q_min+K(delta_Q_max-delta_Q_min). (6)

[0141] The preset critical value is adjusted by adjusting parameter K, but the preset critical value obtained by adjusting K needs to meet certain conditions. In this embodiment, the preset critical value is adjusted using previous soot blowing cycle data.

[0142] A soot blowing cycle Pave can be set. It can be determined by referring to the soot blowing cycle required in the power plant soot blowing procedure, or by statistically analyzing the soot blowing cycles in the boiler's historical data to determine the average soot blowing cycle and the maximum soot blowing cycle Pmax. The average soot blowing cycle can be selected as Pave. By adjusting the value of parameter K multiple times, a preset critical value is obtained each time. The actual soot blowing cycle P(delta_Q) of the soot blower under the preset critical value is calculated, and P(delta_Q) and Pave are compared to see if they are as close as possible. The difference between the two can be compared with a preset threshold for judgment. If the difference between the two does not meet the preset threshold, it proves that P(delta_Q) and Pave are not as close as possible, and parameter K needs to be adjusted again. Each time parameter K is adjusted, the above steps are performed once until P(delta_Q) and Pave are as close as possible. That is, at this moment, the preset critical value of parameter K determined based on equation (6) is used as the final preset critical value for step S130.

[0143] Step S140: Determine the reference temperature data corresponding to the water supply flow rate according to the pre-established second piecewise function.

[0144] The second piecewise function is used to characterize the relationship between the feedwater flow rate and the temperature data of the water-cooled wall.

[0145] It is understandable that the temperature data acquired by the temperature measuring cable device will change with the unit load. Therefore, it is necessary to standardize the temperature data to reduce the impact of unit load changes and amplify the impact of ash accumulation. Considering that the unit load is affected by multiple factors, including the turbine valve opening and boiler coal feed, and that furnace soot blowing is related to the boiler, feedwater flow rate can be used to represent the change in unit load. The second piecewise function is used to characterize the relationship between the standardized temperature data and the feedwater flow rate. Based on the current feedwater flow rate, a lookup table is performed from the second piecewise function to determine the standardized temperature data (which can also be referred to as reference temperature data in this embodiment) corresponding to the current feedwater flow rate.

[0146] The second piecewise function can be pre-established using historical data, or engineers can create a lookup table of temperature and feedwater flow rates using past boiler data, or it can be obtained in advance using the known relationship between feedwater flow rate and temperature data.

[0147] An optional embodiment of this application may include the following steps in establishing the second piecewise function: acquiring temperature sample data collected by the data acquisition module of the coal-fired boiler within a preset load range, and water flow sample data corresponding to each temperature data point; determining a temperature curve with the water flow sample data as the independent variable and the temperature sample data as the dependent variable based on each set of temperature sample data and water flow sample data that have a corresponding relationship; performing mean filtering on the temperature sample data corresponding to each water flow sample data point based on the temperature curve to obtain reference temperature data corresponding to each water flow sample data point; determining the relationship function between the water flow sample data point and the reference temperature data point based on each water flow sample data point and the reference temperature data point corresponding to each water flow sample data point, and defining the relationship function as the first piecewise function.

[0148] First, collect temperature data of the outer wall of the water-cooled wall and corresponding feedwater flow data. The corresponding time of the data does not need to be continuous, but the unit load range corresponding to the collected data needs to include the entire load range (50%-100%).

[0149] It is understandable that combustion conditions differ at different locations within the furnace, and the degree of slagging varies at different locations on the water-cooled walls. According to heat transfer theory, severe slagging on the furnace water-cooled walls hinders heat transfer and reduces heat exchange. Therefore, under the same load, the temperature data at different locations on the water-cooled walls will differ. The sootblowing command is determined based on the temperature data of each sootblower at its location. Therefore, it is necessary to collect the water flow rate data and temperature sample data corresponding to each sootblower's location on the water-cooled wall, and determine a corresponding second piecewise function.

[0150] Optionally, the collected feedwater flow data can be sorted from smallest to largest, and the temperature data can also be changed according to the sorting of the corresponding feedwater flow data, so as to obtain a curve with feedwater flow as the x-axis and water-cooled wall temperature data as the y-axis, i.e. the temperature curve mentioned above.

[0151] Furthermore, mean filtering is applied to the temperature data in the temperature curve, with a fixed filtering interval [am, a+m] defined, where 'a' represents any feedwater flow rate data in the temperature curve, and 'm' is a set value. The mean of the temperature data corresponding to all feedwater flow rate data within this filtering interval is calculated, and the resulting mean heat absorption of the water-cooled wall is used as the reference temperature data for the interval's center point 'a'. Based on this, each feedwater flow rate sample data in the temperature curve is traversed, and filtering calculations are performed using each sample data as the center point of the filtering interval to obtain the reference temperature data corresponding to each feedwater flow rate data in the temperature curve.

[0152] Based on the reference temperature data corresponding to each of the aforementioned water flow rates, the relationship between the reference temperature data, the mean filtering parameters, and the water flow rate is obtained, as expressed by the following equation (7):

[0153]

[0154] In Equation 7, a represents the water supply flow rate, m represents the interval parameter of the mean filter, n represents the maximum water supply flow rate, and T' a This represents the normalized reference temperature data corresponding to the water flow rate 'a'.

[0155] Furthermore, based on the above equation (7), a one-to-one correspondence is obtained between the feedwater flow rate and the reference temperature data (or the normalized temperature data) of the water-cooled wall. A piecewise function of the feedwater flow rate and the normalized temperature data of the water-cooled wall is established, namely the first piecewise function, as shown in equation (8).

[0156]

[0157] In equation (8), amin is the minimum water supply flow rate in the above water supply flow rate data, amax is the maximum water supply flow rate in the above water supply flow rate data, i represents the real-time value of the water supply flow rate, and T amin 'T represents the temperature data of the water-cooled wall corresponding to the minimum feedwater flow rate.' amax 'This represents the temperature data of the water-cooled wall corresponding to the maximum feedwater flow rate, a' i-1 a is the smaller water flow rate value adjacent to the real-time water flow rate value in the above water flow rate data. i+1 T is the larger water flow rate value adjacent to the real-time water flow rate value in the above water flow rate data. ai-1 'For the water supply flow rate a i-1 The corresponding water-cooled wall temperature data, T ai+1 'For the water supply flow rate a i+1 The corresponding temperature data for the water-cooled wall.

[0158] As can be seen from the above, by substituting the current water flow rate into equation (8) and looking up the table, the normalized temperature data obtained is used as reference temperature data to reflect the average temperature level of the water-cooled wall at this location under the current unit load. If the actual temperature data of the water-cooled wall at this location is less than the reference temperature data, it proves that the heat transfer capacity of the current water-cooled wall is below the average level, and the ash accumulation is serious, requiring soot blowing as a reminder. Further, steps S150 and subsequent steps are executed to achieve soot blowing at this location.

[0159] In step S140, the reference temperature data corresponding to the current water flow rate can be determined by looking up the table in equation (8) based on the current water flow rate.

[0160] Step S150: Based on the comparison result between the temperature data of each soot blower and the reference temperature data, determine the soot blowing control command.

[0161] The soot blowing control commands include: an on or off command corresponding to each soot blower;

[0162] Understandably, temperature data for a single sootblower is obtained by measuring points on both sides of the temperature measuring cable, and sootblowing recommendations are determined. The water-cooled wall temperature of the individual sootblower changes rapidly. By using historical values ​​of the water-cooled wall temperature data, i.e., the reference temperature data determined in step S140 above, the sootblowing limit for a single sootblower is determined. When the water-cooled wall temperature data is lower than the limit, it indicates that the slagging at the corresponding location of the water-cooled wall is severe, and sootblowing with a single sootblower is required.

[0163] Optionally, in this embodiment of the application, the process of determining the soot blowing control command by comparing the reference temperature data and the real-time temperature data may include: performing the following steps for the temperature data of each soot blower: determining whether the temperature data is less than the reference temperature data; if the temperature data is less than the reference temperature data, determining the opening command corresponding to the soot blower; if the temperature data is not less than the reference temperature data, determining the closing command corresponding to the soot blower; and determining the soot blowing control command based on the opening command or the closing command corresponding to each soot blower.

[0164] Since the process of determining the soot blowing of each soot blower is the same, this application embodiment will describe any one of them, and the determination process of other soot blowers can be referred to. The reference temperature data Ta determined in step S140 is compared with the temperature data T of the current time corresponding to the soot blower. The comparison result includes two types, which can be referred to the following formula (9).

[0165]

[0166] In equation (9), Brec is the recommended soot blowing instruction, where 1 indicates recommended soot blowing and 0 indicates not recommended soot blowing. The recommended soot blowing instructions for each soot blower are collected to generate the soot blowing control instructions.

[0167] Step S160: Send the soot blowing cycle value and the soot blowing control command to the control module.

[0168] So that the control module takes the current time as the starting point and, when the accumulated time reaches the soot blowing cycle value, controls the opening or closing of each soot blower according to the soot blowing control command.

[0169] Sootblowing control commands are issued by the sootblowing command generation module and sent to the control module or DCS system. The DCS system and the control module serve the same function: automatically controlling the opening and closing of each sootblower. Optional DCS systems include a furnace sootblowing interface, which displays the on / off status of each sootblower. When the controller in the DCS system controls the opening or closing of the sootblowers according to the sootblowing control commands and the sootblowing cycle, the status of each sootblower can be displayed on the furnace sootblowing interface, facilitating engineers' understanding of the status of components inside the furnace.

[0170] It is understandable that the sootblowing cycle represents the frequency of sootblowing by the sootblower. The sootblowing control command needs to be combined with the sootblowing cycle to control the sootblower. When the cumulative time since the last sootblowing reaches the sootblowing cycle, each sootblowing control command will then activate the sootblower. Therefore, the control model, controller, or DCS system responsible for controlling the sootblower needs to monitor not only the sootblower's on / off status but also time monitoring to prevent overblowing or underblowing.

[0171] In summary, this application embodiment involves arranging a set of temperature measuring cables around the distribution height of the sootblowers on the inner wall of the furnace to collect temperature data at different heights within the furnace. This facilitates the acquisition of temperature data from measuring points at different locations on the water-cooled wall tubes. Based on the local temperature data corresponding to different measuring points, it is determined whether there is a need for soot blowing at that point, thereby determining the activation command for the sootblower corresponding to the measuring point with the need for soot blowing. Simultaneously, combined with the current water flow rate, a soot blowing cycle suitable for the current heat absorption of the water-cooled wall is determined. The control module accurately controls the activation of each sootblower based on the soot blowing cycle and the soot blowing command. This application achieves precise control of each sootblower from both the perspectives of soot blowing frequency and soot blowing demand. Each sootblower is activated as needed, and the soot blowing cycle is adjusted in real time, which can precisely control the slag-cleaning effect of each sootblower on local slag formations in the furnace, avoiding over-blowing or under-blowing of the water-cooled wall tubes.

[0172] Furthermore, the in-furnace soot blowing control method for the coal-fired furnace will be described in detail based on the following embodiments.

[0173] Optionally, considering the frequency of soot blowing, if the determined soot blowing cycle is too short, it may cause overblowing due to frequent soot blowing. If the soot blowing cycle is too long, it may cause long-term accumulation of slag in the furnace, and if the soot blowing frequency is too low, it may cause underblowing, which seriously affects the heat absorption capacity of the water-cooled wall tubes. Therefore, this application also proposes a method for limiting the soot blowing cycle.

[0174] Optionally, after obtaining the soot blowing cycle in step S130, the method further includes: determining the difference between the current time and the time when the soot blower was last turned on as the initial soot blowing cycle value; determining whether the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value; when the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value, determining the initial soot blowing cycle value as the soot blowing cycle value of the soot blower; when the initial soot blowing cycle value is greater than the maximum soot blowing cycle value, determining the maximum soot blowing cycle value as the soot blowing cycle value of the soot blower; when the initial soot blowing cycle value is less than the average soot blowing cycle value, determining the average soot blowing cycle value as the soot blowing cycle value of the soot blower.

[0175] The soot blowing cycle determined in step S130 is recorded as the initial soot blowing cycle. In this embodiment, the limit range of the soot blowing cycle is defined by the average soot blowing cycle Pave and the maximum soot blowing cycle Pmax determined from historical soot blowing cycle data. Optionally, engineers can also limit the limit range of the soot blowing cycle according to the soot blowing procedure based on the actual operating conditions of the boiler, or based on the minimum and maximum values ​​of the soot blowing cycle from historical data. This embodiment only provides a framework for limiting the soot blowing cycle and does not impose a unique limitation on the specific limit range.

[0176] Optionally, the initial soot blowing cycle can be compared with the above limit range to determine the final soot blowing cycle TIME_BLOW. The comparison result can be referred to the following formula (10).

[0177]

[0178] When the initial soot blowing cycle is within the limit range, the initial soot blowing cycle is determined as the final soot blowing cycle. When the initial soot blowing cycle is less than the minimum limit of the limit range, i.e., less than the average soot blowing cycle Pave, the final soot blowing cycle is determined as the average soot blowing cycle Pave. When the initial soot blowing cycle is greater than the minimum limit of the limit range, i.e., greater than the maximum soot blowing cycle Pmax, the final soot blowing cycle is determined as the maximum soot blowing cycle Pmax. Based on this, by setting upper and lower limits for the soot blowing cycle, situations of over-blowing and under-blowing are avoided.

[0179] Furthermore, after determining the soot blowing cycle and soot blowing control instructions, these are sent to the control module to control each soot blower to start soot blowing at the correct time. However, the start-up of the soot blower also needs to take into account the steam supply pressure and the condensate temperature. Therefore, the soot blowing control system in the coal-fired boiler also includes: monitors respectively installed at the outlet of the steam supply main and the outlet of the condensate main, used to monitor the steam supply pressure value of the steam supply main and the condensate temperature value of the condensate main. The steam supply main and the condensate main are connected to the soot blower to provide soot blowing steam to the soot blower.

[0180] When the sootblower is turned on, it not only needs the control command issued by the empty box module, but also the steam pressure and temperature of the steam supply main and the drain main in the sootblowing pipeline must reach a level that allows for sootblowing. Therefore, monitors are installed at the outlet of the steam supply main and the outlet of the drain main in the sootblowing pipeline to monitor the steam supply pressure and temperature in the pipeline, so as to ensure that all indicators of the sootblower are in a state that allows for sootblowing when it is necessary to start the sootblower.

[0181] Monitors installed at the outlets of the steam supply main and the drain main of the soot blowing pipeline will transmit the monitored steam pressure and temperature data to the soot blowing command generation module in real time. The module will then judge whether the steam pressure and temperature data meet the soot blowing conditions. If they do, the module will send the soot blower's number or other identification information to the control module so that the control module can scientifically control each soot blower.

[0182] The process by which the soot blowing command generation module determines whether the steam supply pressure and temperature data meet the soot blowing conditions may include: acquiring the steam supply pressure value of the steam supply main pipe and the condensate temperature value of the condensate drain pipe monitored by the monitor; determining that the soot blowing steam currently used for soot blowing meets the soot blowing conditions when the steam supply pressure value reaches a first set value and the condensate temperature value reaches a second set value; and sending the identification information indicating that the soot blowing steam currently used for soot blowing meets the soot blowing conditions to the control module, so that the control module, taking the current time as the starting point, controls the opening or closing of each soot blower according to the soot blowing control command corresponding to each soot blower and the identification information when the accumulated time reaches the soot blowing cycle value.

[0183] It is understandable that the sootblowing conditions of a sootblower require that there be no water in the sootblowing pipe, only steam, and that the pressure inside the pipe reaches a certain value so that the steam can be sprayed out to achieve the sootblowing effect. Based on this, corresponding first and second set values ​​are established for the steam supply pressure and the condensate temperature, respectively. When the steam supply pressure and the condensate temperature reach their respective set values, it can be determined that the sootblowing pipe of the sootblower meets the sootblowing conditions.

[0184] The following describes the coal-fired furnace soot blowing control device provided in the embodiments of this application. The coal-fired furnace soot blowing control device described below can be referred to in correspondence with the coal-fired furnace soot blowing control method described above.

[0185] First, combined Figure 4 The following describes the coal-fired furnace soot blowing control device applied to the soot blowing command generation module in the aforementioned coal-fired furnace soot blowing control system, such as... Figure 4 As shown, the in-furnace soot blowing control device for this coal-fired furnace may include:

[0186] The data acquisition unit 100 is used to acquire the current water flow rate and the temperature data of each soot blower collected by the data acquisition module.

[0187] The heat absorption determination unit 200 is used to process the water flow rate based on a pre-established first piecewise function and a preset heat absorption algorithm, and to determine the theoretical heat absorption of the water-cooled wall corresponding to the water flow rate and the current actual heat absorption of the water-cooled wall. The first piecewise function is used to characterize the characteristic relationship between the water flow rate and the theoretical heat absorption of the water-cooled wall.

[0188] The soot blowing cycle value determination unit 300 is used to take the difference between the current time and the time when the soot blower was last turned on as the soot blowing cycle value when the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value.

[0189] The reference temperature data determination unit 400 is used to determine the reference temperature data corresponding to the water flow rate according to a pre-established second piecewise function, wherein the second piecewise function is used to characterize the characteristic relationship between the water flow rate and the temperature data of the water-cooled wall;

[0190] The instruction determination unit 500 is used to determine a soot blowing control instruction based on the comparison result between the temperature data of each soot blower and the reference temperature data. The soot blowing control instruction includes: an opening instruction or a closing instruction corresponding to each soot blower.

[0191] The instruction issuing unit 600 is used to send the soot blowing cycle value and the soot blowing control instruction to the control module, so that the control module takes the current time as the starting point and controls each soot blower to open or close according to the soot blowing control instruction when the accumulated time reaches the soot blowing cycle value.

[0192] In summary, this embodiment of the application sets up a set of temperature measuring cables around the distribution height of the sootblowers on the inner wall of the furnace to collect temperature data at different heights within the furnace. This facilitates the acquisition of temperature data from measuring points at different locations on the water-cooled wall tubes. Based on the local temperature data corresponding to different measuring points, it is determined whether there is a need for soot blowing at that point, thereby determining the activation command for the sootblower corresponding to the measuring point with soot blowing needs. Simultaneously, combined with the current water flow rate, a soot blowing cycle suitable for the current heat absorption of the water-cooled wall is determined. The control module accurately controls the activation of each sootblower based on the soot blowing cycle and the soot blowing command. This embodiment of the application achieves precise control of each sootblower from both the aspects of soot blowing frequency and soot blowing needs. Each sootblower is activated as needed, and the soot blowing cycle is adjusted in real time, which can precisely control the slag-cleaning effect of each sootblower on local slag formations in the furnace, avoiding over-blowing or under-blowing of the water-cooled wall tubes.

[0193] Optionally, the instruction determining unit 500 includes:

[0194] For each of the soot blowers, the following steps are performed based on the temperature data:

[0195] A temperature determination subunit is used to determine whether the temperature data is less than the reference temperature data;

[0196] The instruction determines the first subunit, which is used to determine the opening instruction corresponding to the soot blower when the judgment result of the temperature judgment subunit is yes;

[0197] The instruction determines the second subunit, which is used to determine the corresponding shutdown instruction for the soot blower when the judgment result of the temperature judgment subunit is negative;

[0198] The instruction integration subunit is used to determine the soot blowing control instruction based on the opening instruction or the closing instruction corresponding to each of the soot blowers.

[0199] Optionally, the data acquisition unit 100 includes:

[0200] The initial temperature data acquisition subunit is used to acquire the first initial temperature data and the second initial temperature data of each preset temperature measurement point on both sides of the soot blower collected by the data acquisition module. The first initial temperature data and the second initial temperature data are temperature data within a preset time period including the current time.

[0201] For each of the soot blowers and the corresponding first initial temperature data and second initial temperature data, the following steps are performed:

[0202] The data noise reduction subunit is used to perform noise reduction processing on the first initial temperature data and the second initial temperature data respectively to obtain the first noise-reduced temperature data corresponding to the first initial temperature data and the second noise-reduced temperature data corresponding to the second initial temperature data.

[0203] The trend determination subunit is used to determine the first data change trend of the first noise-reduced temperature data and the second data change trend of the second noise-reduced temperature data.

[0204] The trend judgment subunit is used to determine whether the trend of the first data change and the trend of the second data change are consistent with the preset data change trend.

[0205] The data determination first subunit is used to determine the temperature data corresponding to the soot blower at the current moment based on either the first noise reduction temperature data or the second noise reduction temperature data when the judgment result of the trend judgment subunit is yes.

[0206] The data determination second subunit is used to determine the temperature data corresponding to the sootblower based on the first noise reduction temperature data when the judgment result of the trend judgment subunit is that the first data change trend is consistent with the preset data change trend and the second data change trend is inconsistent with the preset data change trend.

[0207] The data determination third subunit is used to determine the temperature data corresponding to the sootblower based on the second noise reduction temperature data when the trend judgment subunit determines that the second data change trend is consistent with the preset data change trend and the first data change trend is inconsistent with the preset data change trend.

[0208] Optional, also includes:

[0209] The first sample data acquisition unit is used to acquire sample data of heat absorption of the water-cooled wall of the coal-fired boiler within a preset load range, and sample data of water flow rate corresponding to each sample data of heat absorption.

[0210] The first sub-unit of data graph generation is used to determine a heat absorption curve with the water flow rate sample data as the independent variable and the heat absorption sample data as the dependent variable, based on the heat absorption sample data and the water flow rate sample data of each group of corresponding water-cooled walls.

[0211] The first subunit of mean filtering is used to perform mean filtering on each of the water flow sample data based on the heat absorption curve to obtain the theoretical heat absorption corresponding to each of the water flow sample data.

[0212] The function generates a first sub-unit, which is used to determine the relationship function between the water flow sample data and the theoretical heat absorption based on each water flow sample data and the theoretical heat absorption corresponding to each water flow sample data, and to determine the relationship function as the first piecewise function.

[0213] Optional, also includes:

[0214] The second sample data acquisition unit is used to acquire temperature sample data collected by the data acquisition module of the coal-fired boiler within a preset load range, as well as water flow sample data at the time corresponding to each temperature data point.

[0215] The data graph generation second sub-unit is used to determine a temperature curve graph with the water flow rate sample data as the independent variable and the temperature sample data as the dependent variable, based on each set of temperature sample data and water flow rate sample data that have a corresponding relationship.

[0216] The second subunit of mean filtering is used to perform mean filtering on the temperature sample data corresponding to each of the water flow rate sample data based on the temperature curve to obtain the reference temperature data corresponding to each of the water flow rate sample data.

[0217] The function generates a second sub-unit, which is used to determine the relationship function between the water flow sample data and the reference temperature data based on each of the water flow sample data and the reference temperature data corresponding to each of the water flow sample data, and to determine the relationship function as the first piecewise function.

[0218] Optional, also includes:

[0219] The data acquisition unit is used to acquire the actual heat absorption of the water-cooled wall of the coal-fired boiler within a preset time range and the theoretical heat absorption corresponding to the actual heat absorption.

[0220] The difference data determination unit is used to determine difference sample data based on the difference between the actual heat absorption within the preset time range and the theoretical heat absorption corresponding to the actual heat absorption.

[0221] The difference filtering unit is used to determine the maximum difference and the minimum difference from the difference sample data;

[0222] The periodic data determination unit is used to determine the average and maximum values ​​of the soot blowing cycle based on the soot blowing history data of the coal-fired boiler.

[0223] The parameter value adjustment unit is used to determine the initial preset parameter value by adjusting the relationship coefficient of the relationship function between the maximum difference and the minimum difference;

[0224] The actual cycle determination unit is used to determine the actual soot blowing cycle corresponding to the preset heat absorption difference based on the initial preset parameter value.

[0225] A cycle determination unit is used to determine whether the difference between the soot blowing cycle and the average value of the soot blowing cycle meets a preset threshold.

[0226] The coefficient cycle adjustment unit is used to execute the step of the parameter value adjustment unit to determine the initial preset parameter value by adjusting the relationship coefficient between the preset parameter value and the maximum difference and the minimum difference when the judgment result of the cycle judgment unit is negative, until the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold.

[0227] The critical value determination unit is used to determine a preset critical value based on the relationship coefficient at the current time and the relationship function between the maximum difference and the minimum difference when the judgment result of the parameter value adjustment unit is yes.

[0228] Optional, also includes:

[0229] The initial soot blowing cycle determination unit is used to determine the difference between the current time and the time when the soot blower was last turned on as the initial soot blowing cycle value.

[0230] The period interval judgment unit is used to determine whether the initial soot blowing cycle value is within the range defined by the average value of the soot blowing cycle and the maximum value of the soot blowing cycle;

[0231] The first unit for determining the soot blowing cycle is used to determine the initial soot blowing cycle value as the soot blowing cycle value of the soot blower when the judgment result of the cycle interval judgment unit is yes.

[0232] The second unit for determining the soot blowing cycle is used to determine the maximum soot blowing cycle value as the soot blowing cycle value of the soot blower when the determination result of the cycle interval determination unit is that the initial soot blowing cycle value is greater than the maximum soot blowing cycle value.

[0233] The first unit for determining the soot blowing cycle is used to determine the average soot blowing cycle value as the soot blowing cycle value of the soot blower when the judgment result of the cycle interval judgment unit is that the initial soot blowing cycle value is less than the average soot blowing cycle value.

[0234] Optional, also includes:

[0235] The monitoring data acquisition unit is used to acquire the steam pressure value of the steam supply main pipe and the condensate temperature value of the condensate drain pipe obtained by the monitor.

[0236] The soot blowing condition judgment unit is used to determine that the soot blowing steam currently used for soot blowing meets the soot blowing conditions when the steam supply pressure reaches a first set value and the hydrophobic temperature reaches a second set value.

[0237] The soot blowing judgment result sending unit is used to send the identification information indicating that the soot blowing steam currently used for soot blowing meets the soot blowing conditions to the control module, so that the control module takes the current time as the starting point and, when the cumulative time reaches the soot blowing cycle value, controls the opening or closing of each soot blower according to the soot blowing control command corresponding to each soot blower and the identification information.

[0238] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0239] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0240] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling soot blowing inside a coal-fired furnace, characterized in that, A soot blowing command generation module is applied to a soot blowing system in a coal-fired furnace. The soot blowing system further includes: a data acquisition module for collecting temperature data at temperature measurement points on the soot blowing cables, arranged around a set of temperature measuring cables at the corresponding height of the soot blowers on the inner wall of the furnace; and a control module. The soot blowing method in the coal-fired furnace includes: The system acquires the current water flow rate and the temperature data for each soot blower collected by the data acquisition module. Based on the pre-established first piecewise function and the preset heat absorption algorithm, the water flow rate is processed respectively to determine the theoretical heat absorption of the water-cooled wall corresponding to the water flow rate and the current actual heat absorption of the water-cooled wall. The first piecewise function is a function used to characterize the characteristic relationship between the water flow rate and the theoretical heat absorption of the water-cooled wall. If the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value, the difference between the current time and the time when the soot blower was last turned on is taken as the soot blowing cycle value. Based on a pre-established second piecewise function, reference temperature data corresponding to the water flow rate is determined. The second piecewise function is a function used to characterize the relationship between the water flow rate and the reference temperature data of the water-cooled wall. Based on the comparison between the temperature data of each sootblower and the reference temperature data, a sootblowing control command is determined, which includes: an opening command or a closing command corresponding to each sootblower; The soot blowing cycle value and the soot blowing control command are sent to the control module, so that the control module takes the current time as the starting point and controls each soot blower to turn on or off according to the soot blowing control command when the accumulated time reaches the soot blowing cycle value.

2. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, The determination of soot blowing control commands based on the comparison results between the temperature data of each soot blower and the reference temperature data includes: For each of the soot blowers, the following steps are performed based on the temperature data: Determine whether the temperature data is lower than the reference temperature data; If the temperature data is lower than the reference temperature data, a start command for the soot blower is determined. If the temperature data is not less than the reference temperature data, a shutdown command corresponding to the soot blower is determined; Based on the opening or closing command corresponding to each of the soot blowers, a soot blowing control command is determined.

3. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, The temperature data for each sootblower acquired by the data acquisition module at the current moment includes: The data acquisition module acquires the first initial temperature data and the second initial temperature data of each preset temperature measurement point on both sides of the soot blower. The first initial temperature data and the second initial temperature data are temperature data within a preset time period including the current moment. For each of the soot blowers and the corresponding first initial temperature data and second initial temperature data, the following steps are performed: The first initial temperature data and the second initial temperature data are respectively subjected to noise reduction processing to obtain the first noise-reduced temperature data corresponding to the first initial temperature data and the second noise-reduced temperature data corresponding to the second initial temperature data. Determine the first data change trend of the first noise reduction temperature data and the second data change trend of the second noise reduction temperature data; Determine whether the trend of change of the first data and the trend of change of the second data are consistent with the preset trend of change of data; If the first data change trend and the second data change trend are consistent with the preset data change trend, the temperature data corresponding to the soot blower at the current moment is determined based on either the first noise reduction temperature data or the second noise reduction temperature data. If the first data change trend is consistent with the preset data change trend, and the second data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the first noise reduction temperature data. If the second data change trend is consistent with the preset data change trend, and the first data change trend is inconsistent with the preset data change trend, the temperature data corresponding to the soot blower is determined based on the second noise reduction temperature data.

4. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, The process of pre-establishing the first piecewise function includes: Acquire sample data of heat absorption of the water-cooled wall of the coal-fired boiler within a preset load range, and sample data of water flow rate corresponding to each sample data of heat absorption; Based on the heat absorption sample data and water flow rate sample data of each group of water-cooled walls that have a corresponding relationship, a heat absorption curve is determined with the water flow rate sample data as the independent variable and the heat absorption sample data as the dependent variable. Based on the heat absorption curve, mean filtering is performed on each of the water flow rate sample data to obtain the theoretical heat absorption corresponding to each of the water flow rate sample data. Based on each water flow rate sample data and the theoretical heat absorption corresponding to each water flow rate sample data, a relationship function between the water flow rate sample data and the theoretical heat absorption is determined, and the relationship function is determined as the first piecewise function.

5. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, The process of pre-establishing the second piecewise function includes The temperature sample data collected by the data acquisition module of the coal-fired boiler within the preset load range, and the water flow sample data at the corresponding time of each temperature data are obtained. Based on each set of temperature sample data and water flow sample data that have a corresponding relationship, a temperature curve is determined with the water flow sample data as the independent variable and the temperature sample data as the dependent variable. Based on the temperature curve, mean filtering is performed on the temperature sample data corresponding to each water flow rate sample data to obtain the reference temperature data corresponding to each water flow rate sample data. Based on each water flow rate sample data and the corresponding reference temperature data, a relationship function between the water flow rate sample data and the reference temperature data is determined, and the relationship function is defined as a first piecewise function.

6. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, The process of obtaining the preset threshold value includes: Obtain the actual heat absorption of the water-cooled wall of the coal-fired boiler within a preset time range and the theoretical heat absorption corresponding to the actual heat absorption; Based on the difference between the actual heat absorption within the preset time range and the theoretical heat absorption corresponding to the actual heat absorption, difference sample data is determined; From the difference sample data, determine the maximum and minimum differences; Based on the historical data of soot blowing of the coal-fired boiler, the average soot blowing cycle and the maximum soot blowing cycle are determined; The initial preset parameter value is determined by adjusting the relationship coefficient of the function between the maximum difference and the minimum difference; Based on the initial preset parameter values, determine the actual soot blowing cycle corresponding to the preset heat absorption difference; Determine whether the difference between the soot blowing cycle and the average value of the soot blowing cycle meets a preset threshold. When the difference between the soot blowing cycle and the average value of the soot blowing cycle does not meet the preset threshold, the step of determining the initial preset parameter value by adjusting the relationship coefficient between the preset parameter value and the maximum difference and the minimum difference is executed until the difference between the soot blowing cycle and the average value of the soot blowing cycle meets the preset threshold. When the difference between the soot blowing cycle and the average value of the soot blowing cycle meets a preset threshold, a preset critical value is determined based on the relationship coefficient at the current moment and the relationship function between the maximum difference and the minimum difference.

7. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, Also includes: The difference between the current time and the time when the soot blower was last turned on is determined as the initial soot blowing cycle value; Determine whether the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value; When the initial soot blowing cycle value is within the range defined by the average soot blowing cycle value and the maximum soot blowing cycle value, the initial soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower. When the initial soot blowing cycle value is greater than the maximum soot blowing cycle value, the maximum soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower; When the initial soot blowing cycle value is less than the average soot blowing cycle value, the average soot blowing cycle value is determined to be the soot blowing cycle value of the soot blower.

8. The method for controlling soot blowing inside a coal-fired furnace according to claim 1, characterized in that, Also includes: The steam pressure value of the steam supply main and the condensate temperature value of the condensate drain main are obtained from the monitoring device. When the steam supply pressure reaches the first set value and the condensate temperature reaches the second set value, it is determined that the soot blowing steam currently used for soot blowing meets the soot blowing conditions. The identification information indicating that the soot blowing steam currently used for soot blowing meets the soot blowing conditions is sent to the control module, so that the control module takes the current time as the starting point and, when the accumulated time reaches the soot blowing cycle value, controls the opening or closing of each soot blower according to the soot blowing control command corresponding to each soot blower and the identification information.

9. A coal-fired furnace in-furnace soot blowing control system, characterized in that, The method is applied to a coal-fired furnace, which includes at least a furnace wall, a water-cooled wall, and multiple soot blowers installed on the furnace wall. The soot blowers are distributed at different heights on the furnace wall. The coal-fired furnace soot blowing control system includes a set of temperature measuring cables arranged around the inner wall of the furnace wall at the heights corresponding to the distribution of the soot blowers. The temperature measuring cables are used to detect the temperature data at each preset temperature measuring point set on the temperature measuring cables. A data acquisition module set at a preset temperature measurement point is used to collect the temperature data of the temperature measuring cable at the temperature measurement point; A soot blowing instruction generation module is used to execute the in-furnace soot blowing control method for coal-fired furnaces as described in any one of claims 1-8; The control module is used to receive the soot blowing control command and the soot blowing cycle value sent by the soot blowing command generation module, and, taking the current time as the starting point, respond to the soot blowing control command when the accumulated time reaches the soot blowing cycle value, control the opening or closing of each soot blower.

10. The coal-fired furnace in-furnace soot blowing control system according to claim 9, characterized in that, Also includes: Monitors are installed at the outlet of the steam supply main and the outlet of the drain main, respectively, to monitor the steam pressure of the steam supply main and the drain temperature of the drain main. The steam supply main and the drain main are connected to the soot blower to provide soot blowing steam to the soot blower.

11. A coal-fired furnace in-furnace soot blowing control device, characterized in that, The soot blowing instruction generation module applied to the soot blowing system in the coal-fired furnace according to claim 8, wherein the soot blowing device in the coal-fired furnace comprises: The data acquisition unit is used to acquire the current water flow rate and the temperature data of each soot blower collected by the data acquisition module. The heat absorption determination unit is used to process the water supply flow rate based on a pre-established first piecewise function and a preset heat absorption algorithm, and to determine the theoretical heat absorption of the water-cooled wall corresponding to the water supply flow rate and the current actual heat absorption of the water-cooled wall. The first piecewise function is used to characterize the characteristic relationship between the water supply flow rate and the theoretical heat absorption of the water-cooled wall. The soot blowing cycle value determination unit is used to determine the soot blowing cycle value by taking the difference between the current time and the time when the soot blower was last turned on when the difference between the actual heat absorption and the theoretical heat absorption is less than a preset critical value. The reference temperature data determination unit is used to determine the reference temperature data corresponding to the water flow rate according to a pre-established second piecewise function, wherein the second piecewise function is used to characterize the characteristic relationship between the water flow rate and the temperature data of the water-cooled wall; The instruction determination unit is used to determine a soot blowing control instruction based on the comparison result between the temperature data of each soot blower and the reference temperature data. The soot blowing control instruction includes: an opening instruction or a closing instruction corresponding to each soot blower. The instruction issuing unit is used to send the soot blowing cycle value and the soot blowing control instruction to the control module, so that the control module, with the current time as the starting point, controls the opening or closing of each soot blower according to the soot blowing control instruction when the accumulated time reaches the soot blowing cycle value.

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