A boiler heating surface safety monitoring method, device, equipment and application

Abstract

The present application relates to the technical field of power plant boiler safe operation, and more particularly to a boiler heating surface safety monitoring method, device, equipment and application, comprising: obtaining the furnace flame center temperature, obtaining multi-angle furnace thermal imaging images, assigning coordinates of high-temperature points of the multi-angle furnace thermal imaging images, obtaining a marked furnace thermal imaging image, calculating the high-temperature point area flue gas heat release based on the upstream flue gas temperature, the downstream flue gas temperature and the flue gas mass flow, generating working condition proportion data based on the high-temperature point area flue gas heat release, the heat absorption of the working medium in the pipe section and the heat absorption of the metal pipe material, merging the working condition proportion data with the boiler parameters to obtain working condition relationship data set, using the trained boiler monitoring model for prediction to obtain predicted working condition proportion data, and calculating the highest metal wall temperature of the heating surface pipe material, which realizes accurate detection of the highest metal wall temperature of the heating surface pipe and effectively avoids the over-temperature of the boiler heating surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of safe operation of power plant boilers, and in particular to a boiler heating surface safety monitoring method, device, equipment and application. BACKGROUND

[0002] In recent years, new energy power such as photovoltaic, solar and wind power has developed rapidly, and traditional coal-fired units need to undertake more and more peak shaving tasks. When participating in the peak shaving task, the unit load will be frequently raised and lowered, and the heating surface of each level of the boiler is subjected to frequent changes in thermal stress, and the safety of the metal pipe material is greatly tested.

[0003] As shown in Figure 1 The heating surface of the power plant boiler usually refers to the metal surface on the side contacting the flame or flue gas (the other side contacts water). The heating surface is composed of multiple tubes, the inside of the tube is the working medium (water or steam), and the outside of the tube is high-temperature flue gas. The heat exchange of the boiler is carried out through such a metal surface. At present, in order to avoid the metal wall temperature of the heating surface tube, a thermowell is usually welded at the inlet and outlet of the tube to connect the thermocouple with the tube wall, so as to measure the metal temperature at the inlet and outlet of the tube, which is used as the wall temperature monitoring of the tube. The existing boiler heating surface detection has the following problems: not comprehensive, and the highest temperature cannot be measured. The metal tube of the heating surface is usually several meters or even tens of meters long, and has a side facing the high-temperature flue gas of the furnace (fire-facing side) and a side facing away from the flame and towards the environment of the furnace wall (fire-facing side). Only the metal wall temperature at the inlet and outlet cannot obtain the highest metal wall temperature of the fire-facing side tube in the tube section - and these parts are the most severely roasted and have the most severe working conditions, and are therefore the most dangerous tube sections prone to over-temperature and tube explosion. The data of the boiler tube metal wall temperature measuring point is generally connected to the DCS, and when the temperature of the measuring point exceeds the alarm value, the DCS sends an alarm prompt. The existing method has the problem of not timely intervention, and when the alarm value is reached, it is too late to take adjustment measures because the adjustment of the boiler combustion usually needs several minutes to take effect, and after several minutes, the metal wall temperature of the tube has a high probability of exceeding the limit value. Therefore, the existing method cannot realize wall temperature early warning, so that the monitoring personnel can discover and adjust early to effectively avoid metal wall temperature over-limit.

[0004] In summary, how to accurately detect the highest metal wall temperature of the heating surface tube and effectively avoid over-temperature of the boiler heating surface is a problem to be solved at present. SUMMARY

[0005] The purpose of the present application is to provide a boiler heating surface safety monitoring method, device, equipment and application to solve the problem that the existing boiler metal wall temperature cannot be accurately detected and is prone to over-temperature and tube explosion.

[0006] To solve the above technical problems, the present application provides a kind of boiler heating surface safety monitoring method, comprising:

[0007] Obtain the temperature of furnace flame center, and obtain multi-angle furnace thermal imaging map;

[0008] The high temperature point positioning coordinates of the multi-angle furnace thermal imaging map are assigned, and a marked furnace thermal imaging map is obtained;

[0009] Based on the marked furnace thermal imaging map, the upstream flue gas temperature, downstream flue gas temperature and flue gas mass flow are used to calculate the high temperature point area flue gas heat release;

[0010] Based on the high temperature point area flue gas heat release, the heat absorption of working medium in pipe section and the heat absorption of metal pipe material, working condition proportion data is generated, the working condition proportion data is combined with boiler parameters, and working condition relationship data set is obtained;

[0011] Based on the working condition relationship data set, a boiler monitoring model is trained, and a trained boiler monitoring model is obtained;

[0012] The trained boiler monitoring model is used for prediction, and prediction working condition proportion data is obtained, based on the prediction working condition proportion data and the specific heat capacity of metal pipe material, the highest metal wall temperature of heating surface pipe material is calculated.

[0013] Preferably, the high temperature point positioning coordinates of the multi-angle furnace thermal imaging map are assigned, and a marked furnace thermal imaging map is obtained, comprising:

[0014] The multi-angle furnace thermal imaging map is identified, and based on the infrared radiation intensity, the high temperature point is located;

[0015] Based on the boiler furnace, a furnace coordinate system is established, and the coordinate values of the infrared thermal imaging group are obtained;

[0016] Based on the coordinate values of the infrared thermal imaging group, the coordinate values of the high temperature point are obtained, marked, and a marked furnace thermal imaging map is obtained.

[0017] Preferably, the upstream flue gas temperature, downstream flue gas temperature and flue gas mass flow are used to calculate the high temperature point area flue gas heat release, comprising:

[0018] The upstream flue gas temperature, downstream flue gas temperature and flue gas mass flow are obtained, and the flue gas enthalpy value calculation method is used to obtain the flue gas high temperature point enthalpy difference;

[0019] Based on the flue gas high temperature point enthalpy difference, the high temperature point area flue gas heat release is calculated, and the calculation formula is:

[0020]

[0021] Wherein, The heat released by the flue gas in the high-temperature region For flue gas mass flow rate, This represents the enthalpy difference at the high-temperature point of the flue gas.

[0022] Preferably, after calculating the heat release of the flue gas in the high-temperature region using the upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow rate, the process includes:

[0023] The upstream and downstream working fluid temperatures and working fluid flow rates at the high-temperature point region are obtained. Based on the water vapor enthalpy calculation method, the working fluid enthalpy difference in the high-temperature point region is calculated.

[0024] Based on the enthalpy difference of the working fluid in the high-temperature region, the heat absorbed by the working fluid in the pipeline is calculated using the following formula:

[0025]

[0026] in, The working fluid inside the pipe absorbs heat. For the working fluid flow rate, This represents the enthalpy difference of the working fluid in the high-temperature region.

[0027] Preferably, the heat absorption of the metal pipe is calculated based on the heat release of the flue gas in the high-temperature region and the heat absorption of the working fluid inside the pipe, and the calculation formula is as follows:

[0028]

[0029] in, It absorbs heat for the metal pipes.

[0030] Preferably, the step of generating operating condition ratio data based on the heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe, and merging the operating condition ratio data with boiler parameters to obtain the operating condition relationship dataset includes:

[0031] The heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe are proportionally calculated to generate operating condition ratio data.

[0032] The boiler load data, coal input, feedwater temperature, primary air temperature at air preheater outlet, secondary air temperature at air preheater outlet, feedwater flow rate, total boiler air volume, superheated steam temperature, and reheated steam temperature are combined to generate boiler parameters.

[0033] The operating condition ratio data and the boiler parameters are combined to generate a data set, resulting in an operating condition relationship dataset.

[0034] Preferably, the calculation of the highest metal wall temperature of the heated surface pipe based on the predicted operating condition ratio data and the specific heat capacity of the metal pipe includes:

[0035] The maximum temperature rise value of the metal is calculated based on the heat absorption amount of the metal pipe, and the calculation formula is:

[0036]

[0037] Wherein, The maximum temperature rise value of the metal is calculated based on the heat absorption amount of the metal pipe, and the calculation formula is:

[0038] The highest metal wall temperature is calculated based on the maximum temperature rise value of the metal, and the calculation formula is:

[0039]

[0040] Wherein, The basic temperature of the working medium is calculated based on the maximum temperature rise value of the metal, and the calculation formula is: The outlet temperature of the working medium is calculated based on the maximum temperature rise value of the metal, and the calculation formula is:

[0041] The present application also provides a boiler heating surface safety monitoring device, comprising:

[0042] The data acquisition module obtains the center temperature of the furnace flame to obtain a multi-angle furnace thermal imaging image;

[0043] The thermal imaging marking module assigns values to the high-temperature point positioning coordinates of the multi-angle furnace thermal imaging image to obtain a marked furnace thermal imaging image;

[0044] The heat calculation module calculates the heat release of the high-temperature point area based on the marked furnace thermal imaging image, using the upstream flue gas temperature, the downstream flue gas temperature, and the flue gas mass flow;

[0045] The data set acquisition module generates working condition proportion data based on the heat release of the high-temperature point area, the heat absorption of the working medium in the pipe section, and the heat absorption of the metal pipe, and combines the working condition proportion data with the boiler parameters to obtain a working condition relationship data set;

[0046] The model training module trains a boiler monitoring model based on the working condition relationship data set to obtain a trained boiler monitoring model;

[0047] The wall temperature calculation module uses the trained boiler monitoring model to make predictions to obtain predicted working condition proportion data, and calculates the highest metal wall temperature of the heating surface pipe based on the predicted working condition proportion data and the specific heat capacity of the metal pipe.

[0048] The present application also provides a boiler heating surface safety monitoring device, comprising:

[0049] The infrared thermal imager is used to measure the temperature of the furnace flame;​​​​

[0050] a memory for storing a computer program;

[0051] a processor for implementing the steps of the above-mentioned boiler heating surface safety monitoring method when executing the computer program.

[0052] The application also provides an application of the above-mentioned boiler heating surface safety monitoring method in the technical field of safe operation of power station boilers.

[0053] The boiler heating surface safety monitoring method provided by the application comprehensively monitors the over-temperature condition of the boiler heating surface by using an infrared sensor array, and can provide accurate positioning of the highest metal wall temperature point. With the aid of an infrared thermal imager and an image analysis processing module, the specific position and specific coordinates of the pipe with the highest temperature can be intuitively displayed, thereby providing a guidance basis for accurately and reasonably taking adjustment measures. In combination with an artificial intelligence algorithm and a mathematical calculation formula, the highest metal wall temperature under any load can be obtained, which is more conducive to comprehensive and accurate monitoring of the over-temperature of the heating surface and accurate detection of the highest metal wall temperature of the heating surface pipe, thereby effectively avoiding the over-temperature problem of the heating surface. BRIEF DESCRIPTION OF DRAWINGS

[0054] The above-mentioned and / or additional aspects and advantages of the application will become apparent and easily understood from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0055] Figure 1 It is a schematic diagram of the existing boiler metal wall detection structure;

[0056] Figure 2 It is a flowchart of a first specific embodiment of the boiler heating surface safety monitoring method provided by the application;

[0057] Figure 3 It is a schematic diagram of the arrangement of the infrared thermal imaging array;

[0058] Figure 4 It is a schematic diagram of the positioning of the high-temperature point;

[0059] Figure 5 It is a schematic diagram of the furnace coordinate system;

[0060] Figure 6 It is a structural block diagram of the boiler heating surface safety monitoring device provided by the embodiment of the application;

[0061] In the figure, 1 represents the front wall of the furnace, 2 represents the right wall of the furnace, 3 represents the high-position thermal imager, 4 represents the middle-position thermal imager, and 5 represents the low-position thermal imager. DETAILED DESCRIPTION

[0062] The core of the present application is to provide a boiler heating surface safety monitoring method, device, equipment and application, which realizes accurate detection of the highest metal wall temperature of the heating surface pipeline, effectively avoids the overheating of the heating surface, and is conducive to the comprehensive and accurate monitoring of the overheating of the heating surface.

[0063] In order to enable the personnel in the technical field to better understand the present application scheme, the present application is further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor are within the scope of protection of the present application.

[0064] Please refer to Figure 2 , Figure 2 The flow chart of a first specific embodiment of a boiler heating surface safety monitoring method provided by the present application is shown in the figure, and the specific operation steps are as follows:

[0065] Step S201: Obtain the center temperature of the furnace flame to obtain a multi-angle furnace thermal imaging map;

[0066] Step S202: Assign the high-temperature point positioning coordinates of the multi-angle furnace thermal imaging map to obtain a marked furnace thermal imaging map;

[0067] The multi-angle furnace thermal imaging map is identified and processed, and based on the infrared radiation intensity, the high-temperature point is located;

[0068] Based on the boiler furnace, a furnace coordinate system is established, and the coordinate values of the infrared thermal imaging group are obtained;

[0069] Based on the coordinate values of the infrared thermal imaging group, the coordinate values of the high-temperature point are obtained, marked, and a marked furnace thermal imaging map is obtained.

[0070] Step S203: Based on the marked furnace thermal imaging map, the upstream flue gas temperature, the downstream flue gas temperature, and the flue gas mass flow are used to calculate the flue gas heat release of the high-temperature point area;

[0071] The upstream flue gas temperature, the downstream flue gas temperature, and the flue gas mass flow are obtained, and the flue gas enthalpy difference of the high-temperature point is obtained by using the flue gas enthalpy calculation method;

[0072] Based on the flue gas enthalpy difference of the high-temperature point, the flue gas heat release of the high-temperature point area is calculated, and the calculation formula is:

[0073]

[0074] wherein, is the flue gas heat release of the high-temperature point area, is the flue gas mass flow, is the flue gas enthalpy difference of the high-temperature point.

[0075] Obtaining the upstream working medium temperature, the downstream working medium temperature and the working medium flow rate at the high-temperature point region, and calculating the working medium enthalpy difference at the high-temperature point region based on the water vapor enthalpy calculation method;

[0076] Based on the working medium enthalpy difference at the high-temperature point region, the working medium heat absorption amount in the pipeline is calculated, and the calculation formula is:

[0077]

[0078] Among them, The working medium heat absorption amount in the pipeline, The working medium flow rate, The working medium enthalpy difference at the high-temperature point region.

[0079] Step S204: Based on the flue gas heat release amount at the high-temperature point region, the working medium heat absorption amount in the pipeline and the metal pipe material heat absorption amount, the working condition proportion data is generated, and the working condition proportion data and the boiler parameters are combined to obtain the working condition relationship data set;

[0080] The metal pipe material heat absorption amount is calculated based on the flue gas heat release amount at the high-temperature point region and the working medium heat absorption amount in the pipeline, and the calculation formula is:

[0081]

[0082] Among them, The metal pipe material heat absorption amount;

[0083] The flue gas heat release amount at the high-temperature point region, the working medium heat absorption amount in the pipeline and the metal pipe material heat absorption amount are proportionally calculated to generate working condition proportion data;

[0084] The boiler load data, the coal amount into the furnace, the feed water temperature, the air preheater outlet primary air temperature, the air preheater outlet secondary air temperature, the feed water flow rate, the total air volume of the boiler, the superheated steam temperature and the reheated steam temperature are combined to generate the boiler parameters;

[0085] The working condition proportion data and the boiler parameters are combined to generate a data group, and the working condition relationship data set is obtained.

[0086] Step S205: Based on the working condition relationship data set, a boiler monitoring model is trained to obtain a trained boiler monitoring model;

[0087] Step S206: The trained boiler monitoring model is used for prediction to obtain predicted working condition proportion data, and based on the predicted working condition proportion data and the specific heat capacity of the metal pipe material, the maximum metal wall temperature of the heating surface pipe material is calculated;

[0088] Based on the metal pipe material heat absorption amount, the maximum temperature rise value of the metal temperature is calculated, and the calculation formula is:

[0089]

[0090] wherein, is the maximum temperature rise of the metal, is the heat absorption of the metal pipe, is the specific heat capacity of the metal pipe, is the mass of the pipe;

[0091] The highest metal wall temperature is calculated based on the maximum temperature rise of the metal, and the calculation formula is:

[0092]

[0093] wherein, is the basic temperature of the working medium, is the inlet temperature of the working medium, is the outlet temperature of the working medium.

[0094] The embodiment provides a boiler heating surface safety monitoring method, which comprehensively monitors the over-temperature condition of the boiler heating surface by using an infrared sensor array. Compared with the traditional method of monitoring over-temperature by setting pipe inlet and outlet wall temperature measuring points, the present application can intuitively display the specific position and specific coordinates of the pipe with the highest temperature by means of an infrared thermal imager and an image analysis processing module, and can provide guidance basis for accurately and reasonably taking adjustment measures, can provide accurate positioning of the highest metal wall temperature point, automatically adjust related equipment, and intervene in advance to over-temperature phenomenon, effectively avoiding the problem of over-temperature of the heating surface.

[0095] Based on the above embodiment, the boiler heating surface safety monitoring method is described as follows:

[0096] As shown in Figure 3 , the flame center of the boiler furnace area, that is, the area with the highest temperature, is detected. The furnace of a power plant boiler is mainly surrounded by a four-wall furnace wall formed by a water wall, and a pulverized coal burner is usually arranged in this area. The present application determines the position of the flame center by arranging multiple infrared thermal imagers at different heights around the furnace to form a furnace flame center detection array, shooting infrared thermal imaging images of the furnace from multiple angles and heights, and finally determining the position of the flame center according to the intensity of infrared radiation. The real highest wall temperature of the heating surface is in this area. Through multi-angle shooting combined with the intensity of infrared radiation, the specific position of the high-temperature center of flue gas is determined, and the real highest wall temperature of the heating surface is in this area.

[0097] As shown in Figure 4 , the pictures taken by the infrared thermal imager array are subjected to high-temperature point positioning and coordinate assignment, and finally the specific position of the highest temperature point is obtained (the highest temperature point on the photo is actually located on the heating surface pipe). The specific steps are as follows:

[0098] ①High temperature point positioning. Multiple infrared photos taken by infrared thermal imager array are processed by special infrared image recognition software. According to the collected infrared radiation intensity, the point with the highest temperature, called "high temperature point", can be located.

[0099] ②Unified coordinates. As shown in Figure 5 , first establish the furnace coordinate system, taking the horizontal plane 1.0 m below the lowermost layer of pulverized coal burners in the furnace as the reference plane. The coordinates of the high temperature point on this plane are . The coordinate system is shown in Figure 5 . Each infrared thermal imager can obtain exclusive coordinate values according to its actual installation position (the front and rear walls of the furnace are represented by the letters Q, H, Z, and Y, and the high, medium, and low positions are represented by G, Z, and D. The infrared thermal imager numbers 1, 2, 3, … i are recorded in the order of the coordinate axes). For example, the installation coordinates of the i-th high-position thermal imager on the front wall are .

[0100] For example, the installation coordinates of the i-th high-position thermal imager on the front wall are , and the coordinates of the high temperature point on the picture taken by it can be represented as △z, where △x, △y, and △z are obtained by image ranging software. Taking the picture of the back wall taken by the i-th high-position thermal imager on the front wall as an example, the method of obtaining it is introduced as follows:

[0101] Static calibration. Under the condition that the boiler is extinguished and the furnace is fully illuminated, use standard size markers (such as 2.0 m × 3.0 m, vertically installed on the opposite furnace wall) placed at different positions to take infrared thermal imaging pictures. Under this condition, the calibration picture with markers is obtained;

[0102] Pixel point ranging. Use image recognition software to measure the number of pixel points of each marker. Assuming that the length and width are a: z, corresponding to the actual size 2.0: 3.0, then the scale of the length direction is a / 2, and the scale of the height direction is z / 3;

[0103] Actual picture measurement: Under normal combustion conditions of the boiler, the infrared thermal imaging picture taken by the infrared thermal imager is processed by the image recognition software, and the number of pixel points of a certain point can be obtained. Assuming that it is , then the actual size is length A= × (a / 2) and width Z= × (b / 3);

[0104] Coordinate calculation. Thus, the values of Δx=A and Δz=Z can be obtained, and the value of Δy can be obtained by using the left or right wall thermal imager, and the values of Δy and Δz can be obtained by using the above steps. Finally, the specific values of Δx, Δz, and Δy of the high-temperature point can be obtained, and the specific coordinate values of the high-temperature point in the furnace coordinate system can be obtained Δz.

[0105] Heat calculation. According to the area of the “high-temperature point” on the pipe, the upstream flue gas temperature T1, the downstream flue gas temperature T2, and the flue gas mass flow rate are obtained by measuring the infrared thermal imager, and the enthalpy difference of the flue gas in the “high-temperature point” area is obtained by using the existing flue gas enthalpy calculation method , and then the heat release of the flue gas in the area is = × .

[0106] Similarly, according to the actual measurement of the upstream and downstream working medium (water or steam) temperatures 、 of the “high-temperature point” pipe section by using an industrial temperature meter, and the working medium flow rate , the enthalpy difference of the working medium in the “high-temperature point” area can be obtained by using the water or steam enthalpy calculation software (mature calculation software, not proposed by the present application, not described here), and then the heat absorption of the working medium in the pipe section can be obtained = × .

[0107] In particular, to simplify the calculation, the present application considers that the heat release of the flue gas is absorbed by the metal pipe material and the working medium in the pipe without loss, the heat absorption of the working medium in the pipe is , and the heat absorption of the metal pipe material is defined as , so = + , and and are known, so can also be calculated.

[0108] Thus, the proportional relationship between the flue gas heat release, the working medium heat absorption, and the pipe material heat absorption under a certain working condition can be obtained as = : : .

[0109] ​The proportional relationship is combined with the boiler load, the amount of coal into the furnace, the feed water temperature, the air preheater outlet primary air temperature, the air preheater outlet secondary air temperature, the feed water flow, the total air volume of the boiler, the superheated steam temperature, the reheated steam temperature and other main parameters (all provided by the DCS system of the power plant) to form a "data group", which is defined as , The flue gas heat proportional relationship corresponding thereto is combined as , ).

[0110] The unit changes the parameters, repeats the above steps, and collects a plurality of "data groups" under different working conditions, so as to obtain a plurality of "boiler main parameters, flue gas proportional relationship" relational expressions covering the entire operating range of the unit, such as , ), ( , ), ( , )……( , ) and the like.

[0111] According to the actual working condition parameter values of ( , ), ( , ), ( , )……( , ) and the like, the internal relationship between Z and B is obtained by means of artificial intelligence algorithms (decision tree, random forest, logistic regression, linear regression, naive Bayes, neural network, support vector machine and other artificial learning models), and the specific corresponding relationship between the flue gas heat distribution proportional relationship B and the boiler main parameters Z is established.

[0112] On this basis, in the case of knowing the boiler main parameters Z under any working condition, the artificial intelligence model can be used to reliably predict the flue gas heat distribution proportional relationship B under the working condition. : : ).

[0113] Suppose that the boiler main parameters under a certain working condition are known, and the trained boiler monitoring model is used to predict the corresponding flue gas heat distribution proportional relationship B ( : : ), the heat absorption of the metal pipe material All the action on the "high temperature point" area of a small piece of pipe, assuming the small piece of pipe surface area is 1.0 cm x 1.0 cm, and the wall thickness of the pipe is known as h, the density of the pipe is p, then the mass of the block of pipe m = p x 1.0 cm x 1.0 cm x h

[0114] Again, the specific heat capacity of the known metal pipe is C, by the heat absorption formula =C•m•△t, can obtain the maximum temperature of the small piece of metal △t= / (C×m)。

[0115] The highest metal wall temperature t= +△t, wherein is the base temperature, the average temperature of the working medium (water or steam) in the pipe as estimation value (working medium inlet and outlet temperature can be provided by the unit DCS system), then =( ) / 2, wherein is the base temperature of the working medium, is the working medium inlet temperature, is the working medium outlet temperature.

[0116] In summary, the highest metal wall temperature , this is a specific working condition, the real and reliable heating surface tube material highest metal wall temperature.

[0117] The embodiment also provides an automatic processing device, an automatic control program built in the power plant DCS system, which can obtain the rising amplitude and the change rate of the highest metal wall temperature t of the pipe in real time according to the foregoing steps, automatically take reasonable measures for adjustment intervention, and avoid overheating of the heating surface. The specific measures are shown in Table 1:

[0118] Table 1

[0119]

[0120] The embodiment of the present application provides a kind of boiler heating surface safety monitoring method, can provide the accurate positioning of highest metal wall temperature point. With the aid of infrared thermal imager and image analysis processing module, the specific position of the tube with the highest temperature can be intuitively displayed, specific coordinates are provided to guide the basis for accurately and reasonably taking adjustment measures, and the over-temperature situation can be more comprehensively and accurately reflected. The traditional wall temperature monitoring only relies on the wall temperature measuring point set at the inlet and outlet of the tube to monitor, and the monitoring of the parts other than the head and tail of the tube is in a blank state. The array of the infrared thermal imager of the present application can cover all tubes and all parts of the heating surface, achieving "no omission". Combined with artificial intelligence algorithm and mathematical calculation formula, the highest metal wall temperature under any load can be obtained, which is more conducive to comprehensive and accurate monitoring of the over-temperature of the heating surface. High degree of automation. According to the over-temperature condition, the present application can comprehensively take various measures, automatically adjust the related equipment, and intervene in advance to avoid the over-temperature problem of the heating surface.

[0121] Please refer to Figure 6 , Figure 6 The structure diagram of a boiler heating surface safety monitoring device provided by the embodiment of the present application is provided. The specific device can include:

[0122] The data acquisition module 100 obtains the center temperature of the furnace flame to obtain a multi-angle furnace thermal imaging map;

[0123] The thermal imaging marking module 200 assigns the high-temperature point positioning coordinates of the multi-angle furnace thermal imaging map to obtain a marked furnace thermal imaging map;

[0124] The heat calculation module 300 calculates the high-temperature point area flue gas heat release based on the marked furnace thermal imaging map, using the upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow;

[0125] The data set acquisition module 400 generates working condition proportion data based on the high-temperature point area flue gas heat release, heat absorption of the working medium in the pipe section, and heat absorption of the metal pipe material, combines the working condition proportion data with the boiler parameters to obtain a working condition relationship data set;

[0126] The model training module 500 trains a boiler monitoring model based on the working condition relationship data set to obtain a trained boiler monitoring model;

[0127] The wall temperature calculation module 600 uses the trained boiler monitoring model for prediction to obtain predicted working condition proportion data, and calculates the highest metal wall temperature of the heating surface pipe material based on the predicted working condition proportion data and the specific heat capacity of the metal pipe material.

[0128] The boiler heating surface safety monitoring device of the embodiment is used to implement the boiler heating surface safety monitoring method, and the specific embodiments of the boiler heating surface safety monitoring device can refer to the embodiment part of the boiler heating surface safety monitoring method, for example, the data acquisition module 100, the thermal imaging marking module 200, the heat calculation module 300, the data set acquisition module 400, the model training module 500, and the wall temperature calculation module 600 are respectively used to implement steps S201, S202, S203, S204, S205 and S206 in the boiler heating surface safety monitoring method, so the specific embodiments can refer to the description of the corresponding embodiment part, and details are not described herein again.

[0129] The embodiment of the boiler heating surface safety monitoring device is used to implement the boiler heating surface safety monitoring method, and the specific embodiments of the boiler heating surface safety monitoring device can refer to the embodiment part of the boiler heating surface safety monitoring method, for example, the data acquisition module 100, the thermal imaging marking module 200, the heat calculation module 300, the data set acquisition module 400, the model training module 500, and the wall temperature calculation module 600 are respectively used to implement steps S201, S202, S203, S204, S205 and S206 in the boiler heating surface safety monitoring method, so the specific embodiments can refer to the description of the corresponding embodiment part, and details are not described herein again.

[0130] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0131] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one feature. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0132] Any process or method descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) in the process, and the various embodiments of the present application include additional implementations in which the order of steps can be different, including use of the same or different steps, or additional or fewer steps, are performed in an alternative order or in substantially simultaneous fashion, as appropriate, to implement the functionality associated with the described steps in a manner that is consistent with the teachings of the present application.

[0133] The various embodiments described in the specification are presented for the purpose of illustration and description. Each of the embodiments highlight a certain aspect of the other embodiments to which it pertains and, thus, various embodiments can be described without limitation of the other embodiments. The same or similar reference numerals can be used in different drawings to represent the same or similar components.

[0134] The coal-fired boiler blending combustion system and method provided by the present application is described in detail above. The principles and implementation modes of the present application are described by using specific examples in this paper. The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0135] It should be understood that various parts of the present application can be realized by hardware, software, firmware or a combination thereof. In the above-described embodiments, a plurality of steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if realized by hardware and in another embodiment, any one or a combination of the following technologies known in the art can be used: discrete logic circuit with logic gate circuit for implementing logic functions on data signals, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA), etc.

[0136] Those skilled in the art can understand that all or part of the steps carried out by the above-described embodiments can be instructed by a program to complete the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiments or a combination thereof.

[0137] In addition, each functional unit in each embodiment of the present application can be integrated in one processing module, or each unit can exist physically separately, or two or more units can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software functional module. When the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

Claims

1. A method for safety monitoring of boiler heating surfaces, characterized in that, include: The temperature at the center of the furnace flame is obtained, and multi-angle thermal imaging images of the furnace are obtained. The high-temperature point positioning coordinates of the multi-angle furnace thermal imaging image are assigned and processed to obtain a marked furnace thermal imaging image. Based on the marked furnace thermal imaging image, the heat release of flue gas in the high-temperature region is calculated using the upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow rate. Based on the heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe, operating condition ratio data is generated. The operating condition ratio data is then combined with the boiler parameters to obtain an operating condition relationship dataset. The boiler monitoring model is trained based on the aforementioned operating condition relationship dataset, resulting in a fully trained boiler monitoring model. The boiler monitoring model that has been trained is used to make predictions and obtain the predicted operating condition ratio data. Based on the predicted operating condition ratio data and the specific heat capacity of the metal tube, the highest metal wall temperature of the heated surface tube is calculated. The process of assigning coordinates to the high-temperature points in the multi-angle furnace thermal imaging image to obtain the marked furnace thermal imaging image includes: The multi-angle thermal imaging image inside the furnace is identified and processed, and the high-temperature point is located based on the infrared radiation intensity. Based on the boiler furnace, a furnace coordinate system is established to obtain the coordinate values ​​of the infrared thermal imaging group; Based on the coordinate values ​​of the infrared thermal imaging group, the coordinate values ​​of the high-temperature points are obtained, marked, and a marked thermal imaging map of the furnace is obtained. The operating condition ratio data is generated based on the heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe. This operating condition ratio data is then combined with boiler parameters to obtain an operating condition relationship dataset, which includes: The heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe are proportionally calculated to generate operating condition ratio data. The boiler load data, coal input, feedwater temperature, primary air temperature at air preheater outlet, secondary air temperature at air preheater outlet, feedwater flow rate, total boiler air volume, superheated steam temperature, and reheated steam temperature are combined to generate boiler parameters. The operating condition ratio data and the boiler parameters are combined to generate a data set, resulting in an operating condition relationship dataset.

2. The method as described in claim 1, characterized in that, The calculation of the heat release of flue gas in the high-temperature region based on the marked furnace thermal imaging image, using upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow rate, includes: The upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow rate are obtained, and the enthalpy difference at the high temperature point of the flue gas is obtained using the flue gas enthalpy calculation method. Based on the enthalpy difference at the high-temperature point of the flue gas, the heat release of the flue gas in the high-temperature region is calculated using the following formula: in, The heat released by the flue gas in the high-temperature region For flue gas mass flow rate, This represents the enthalpy difference at the high-temperature point of the flue gas.

3. The method as described in claim 2, characterized in that, The step of calculating the heat release of flue gas in the high-temperature region based on the marked furnace thermal imaging image, using upstream flue gas temperature, downstream flue gas temperature, and flue gas mass flow rate, includes: The upstream and downstream working fluid temperatures and working fluid flow rates at the high-temperature point region are obtained. Based on the water vapor enthalpy calculation method, the working fluid enthalpy difference in the high-temperature point region is calculated. Based on the enthalpy difference of the working fluid in the high-temperature region, the heat absorbed by the working fluid in the pipeline is calculated using the following formula: in, The working fluid inside the pipe absorbs heat. For the working fluid flow rate, This represents the enthalpy difference of the working fluid in the high-temperature region.

4. The method as described in claim 3, characterized in that, The heat absorption of the metal pipe is calculated based on the heat release of the flue gas in the high-temperature region and the heat absorption of the working fluid inside the pipe. The calculation formula is as follows: in, It absorbs heat for the metal pipes.

5. The method as described in claim 1, characterized in that, The calculation of the highest metal wall temperature of the heated surface pipe based on the predicted operating condition ratio data and the specific heat capacity of the metal pipe includes: The maximum temperature rise of the metal is calculated based on the heat absorption of the metal pipe, and the calculation formula is as follows: in, This represents the maximum temperature rise of the metal. For the metal pipe to absorb heat, The specific heat capacity of the metal pipe. For the quality of pipe materials; The highest metal wall temperature is calculated based on the maximum increase in metal temperature, and the calculation formula is as follows: in, The working fluid's base temperature, The inlet temperature of the working fluid. The outlet temperature of the working fluid.

6. A safety monitoring device for boiler heating surfaces, characterized in that, include: The data acquisition module obtains the temperature of the center of the furnace flame and generates multi-angle thermal imaging images of the furnace interior. The thermal imaging marking module assigns and processes the high-temperature point positioning coordinates of the multi-angle furnace thermal imaging map to obtain a marked furnace thermal imaging map. The heat calculation module calculates the heat release of flue gas in the high-temperature area based on the marked furnace thermal imaging map and using the upstream flue gas temperature, downstream flue gas temperature and flue gas mass flow rate. The dataset acquisition module generates operating condition ratio data based on the heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe. The operating condition ratio data is then merged with the boiler parameters to obtain the operating condition relationship dataset. The model training module trains the boiler monitoring model based on the operating condition relationship dataset to obtain the trained boiler monitoring model. The wall temperature calculation module uses the trained boiler monitoring model to make predictions and obtains predicted operating condition ratio data. Based on the predicted operating condition ratio data and the specific heat capacity of the metal pipe, the module calculates the highest metal wall temperature of the heated surface pipe. The process of assigning coordinates to the high-temperature points in the multi-angle furnace thermal imaging image to obtain the marked furnace thermal imaging image includes: The multi-angle thermal imaging image inside the furnace is identified and processed, and the high-temperature point is located based on the infrared radiation intensity. Based on the boiler furnace, a furnace coordinate system is established to obtain the coordinate values ​​of the infrared thermal imaging group; Based on the coordinate values ​​of the infrared thermal imaging group, the coordinate values ​​of the high-temperature points are obtained, marked, and a marked thermal imaging map of the furnace is obtained. The operating condition ratio data is generated based on the heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe. This operating condition ratio data is then combined with boiler parameters to obtain an operating condition relationship dataset, which includes: The heat release of flue gas in the high-temperature area, the heat absorption of the working fluid in the pipe section, and the heat absorption of the metal pipe are proportionally calculated to generate operating condition ratio data. The boiler load data, coal input, feedwater temperature, primary air temperature at air preheater outlet, secondary air temperature at air preheater outlet, feedwater flow rate, total boiler air volume, superheated steam temperature, and reheated steam temperature are combined to generate boiler parameters. The operating condition ratio data and the boiler parameters are combined to generate a data set, resulting in an operating condition relationship dataset.

7. A safety monitoring device for boiler heating surfaces, characterized in that, include: Infrared thermal imager is used to measure the temperature of the furnace flame. Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the boiler heating surface safety monitoring method as described in any one of claims 1 to 5.

8. The application of a boiler heating surface safety monitoring method as described in any one of claims 1-5 in the field of power plant boiler safety operation technology.

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