A method and device for quantitatively calculating a furnace biasing direction and degree of a coal-fired unit

Abstract

The application discloses a kind of coal-fired unit furnace partial burning direction and degree quantitative calculation method and device, it is related to coal-fired unit boiler combustion control technical field, the method of the present application includes: acquisition coal-fired unit furnace multi-source operation data;After the pre-processing of multi-source data, construct furnace three-dimensional temperature-flue gas concentration coupling field model;Based on the feature parameters of each monitoring partition of coupling field model extraction furnace, partial burning direction is determined by vector composition method;Dynamic correction coefficient is introduced to construct partial burning degree quantitative model, and the partial burning degree quantitative value is calculated;Combining unit operating parameter, partial burning direction and degree result are dynamically corrected, and accurate quantitative result is output.The present application realizes the three-dimensional accurate determination of furnace partial burning direction and the multidimensional dynamic quantization of degree, adapts unit variable operating condition, effectively improves the combustion efficiency of coal-fired unit, reduces NO x Emission and furnace local overheating risk, meet the demand of green and low-carbon development, can be widely applied to coal-fired unit boiler operation optimization.

Description

Technical Field

[0001] This invention relates to the field of combustion control technology for coal-fired boiler units, and in particular to a method and apparatus for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired boiler unit. Background Technology

[0002] Coal-fired power units are the core power source in my country's electricity supply. The furnace, as the core combustion space of a coal-fired boiler, directly determines the unit's power generation efficiency, operational safety, and pollutant emission levels through its combustion uniformity. Uneven combustion in the furnace refers to the phenomenon where uneven fuel combustion leads to significant deviations in temperature and flue gas concentration from the average in localized areas. This can easily cause localized overheating and corrosion of the water-cooled walls, and increase NOx emissions. x Problems such as excessive emissions and decreased unit efficiency.

[0003] Existing technologies for detecting uneven burning in the furnace have the following main shortcomings: Qualitative judgment is the primary method: Most power plants rely on manual observation of the furnace flame shape and comparison of local temperature deviations to qualitatively judge uneven combustion. There are no precise quantitative indicators to guide combustion adjustments. Single-dimensional quantification: Some technologies quantify the degree of combustion deviation solely through temperature deviation values, without considering key factors such as flue gas concentration, burner output, and coal quality, resulting in low quantification accuracy. The direction determination is ambiguous: it can only determine two-dimensional directions such as left / right and front / back, and cannot identify the upward / downward or combined combustion direction, resulting in insufficient targeted combustion adjustment; Poor adaptability to changing operating conditions: The influence of operating parameters such as unit load and coal quality changes on uneven combustion is not considered, and the quantitative results have large errors under changing operating conditions. Insufficient modeling accuracy: A three-dimensional coupled field model of the furnace was not constructed, which cannot reflect the spatial distribution characteristics of the combustion state inside the furnace.

[0004] Therefore, there is an urgent need for a calculation method and device that can accurately determine the direction of furnace combustion deviation in three dimensions, dynamically quantify the degree in multiple dimensions, and adapt to the variable operating conditions of the unit, so as to solve the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to propose a method for quantifying the direction and degree of uneven combustion in the furnace of a coal-fired power unit, aiming to solve the problems of qualitative judgment of uneven combustion in the prior art, single quantification dimension, ambiguous direction judgment, and poor adaptability to changing operating conditions.

[0006] This invention is implemented as follows: a method for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired power unit, the method comprising: Collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. The multi-source operational data is preprocessed; Based on the preprocessed multi-source operating data, a three-dimensional temperature-flue gas concentration coupled field model of the furnace is constructed. The coupled field model is based on the geometry of the furnace and divides the furnace into several three-dimensional grid units using the finite element method. Each grid unit is assigned a weighting coefficient for temperature and flue gas concentration. The constructed three-dimensional temperature-flue gas concentration coupled field model of the furnace is as follows: F(x,y,z)=α・T(x,y,z)+(1-α)・C(x,y,z); Where F(x,y,z) is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient, T(x,y,z) is the normalized temperature value of the grid cell (x,y,z), C(x,y,z) is the normalized flue gas concentration value of the grid cell (x,y,z), and x, y, z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired unit furnace; Based on the aforementioned three-dimensional temperature-flue gas concentration coupled field model, the temperature deviation value and flue gas concentration deviation value of each grid cell are extracted. The off-center combustion direction vector is calculated using a vector synthesis method to determine the three-dimensional direction of off-center combustion in the furnace; including: Calculate the temperature deviation and flue gas concentration deviation for each grid cell; ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. Calculate the deviation vector Vᵢ for each mesh element; Vᵢ = (ΔTᵢ・cosθᵢ, ΔTᵢ・sinθᵢ, ΔCᵢ); where θᵢ is the azimuth angle of the mesh element in the xy plane; The deviation vectors of all grid cells are synthesized to obtain the total deviation direction vector V_total. The deviation direction is determined based on the sign and absolute value of V_x, V_y, and V_z. V_total=ΣVᵢ=(V_x,V_y, V_z), where V_X, V_y, and V_z are the components of the total off-center burning direction vector V_total on the x-axis, y-axis, and z-axis of the three-dimensional coordinate system of the furnace, respectively. V_X represents the overall off-center burning trend in the left-right direction of the furnace, V_y represents the overall off-center burning trend in the front-back direction of the furnace, and V_z represents the overall off-center burning trend in the up-down direction of the furnace. Construct a quantitative model for the degree of uneven burning and calculate the quantitative value of the degree of uneven burning; The calculation formula for the quantification model of the degree of uneven burning is as follows: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Where D is the quantitative value of the degree of uneven burning, with a value range of 0-1; β is the dynamic correction coefficient, β= k1・L + k2・M +k3・P, k1, k2, and k3 are weighting coefficients, L is the normalized value of unit load, M is the normalized value of coal volatile matter, P is the unevenness of burner output, N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points; By combining the real-time changes in the unit's operating conditions, the quantification values ​​of the burn-off direction vector and the burn-off degree are dynamically corrected, and the final quantification results of the burn-off direction and degree in the furnace are output. The formula for dynamic correction is: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM); Where V'_total is the corrected eccentricity vector, D' is the corrected eccentricity quantification value, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, and ΔM is the coal volatile matter change rate.

[0007] Another objective of this invention is to provide a device for quantitatively calculating the direction and degree of uneven combustion in a coal-fired power unit furnace, the device comprising: The data acquisition module is used to collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. The preprocessing module is used to preprocess the multi-source running data; The 3D field modeling module is used to construct a 3D temperature-flue gas concentration coupled field model of the furnace based on preprocessed multi-source operating data. This coupled field model is based on the furnace geometry, dividing the furnace into several 3D mesh elements using the finite element method, with each mesh element assigned weight coefficients for temperature and flue gas concentration. The construction of the 3D temperature-flue gas concentration coupled field model of the furnace is as follows: F(x,y,z)=α・T(x,y,z)+(1-α)・C(x,y,z); Where F(x,y,z) is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient, T(x,y,z) is the normalized temperature value of the grid cell (x,y,z), C(x,y,z) is the normalized flue gas concentration value of the grid cell (x,y,z), and x, y, z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired unit furnace; The direction determination module is used to extract the temperature deviation value and flue gas concentration deviation value of each grid cell based on the three-dimensional temperature-flue gas concentration coupled field model, calculate the off-center burning direction vector through vector synthesis method, and determine the three-dimensional direction of off-center burning in the furnace; including: Calculate the temperature deviation and flue gas concentration deviation for each grid cell; ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. Calculate the deviation vector Vᵢ for each mesh element; Vᵢ = (ΔTᵢ・cosθᵢ, ΔTᵢ・sinθᵢ, ΔCᵢ); where θᵢ is the azimuth angle of the mesh element in the xy plane; The deviation vectors of all grid cells are synthesized to obtain the total deviation direction vector V_total. The deviation direction is determined based on the sign and absolute value of V_x, V_y, and V_z. V_total=ΣVᵢ=(V_x,V_y, V_z), where V_X, V_y, and V_z are the components of the total off-center burning direction vector V_total on the x-axis, y-axis, and z-axis of the three-dimensional coordinate system of the furnace, respectively. V_X represents the overall off-center burning trend in the left-right direction of the furnace, V_y represents the overall off-center burning trend in the front-back direction of the furnace, and V_z represents the overall off-center burning trend in the up-down direction of the furnace. The degree quantification module is used to construct a degree quantification model for uneven burning and calculate the degree quantification value for uneven burning; the calculation formula for the degree quantification model for uneven burning is as follows: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Where D is the quantitative value of the degree of uneven burning, with a value range of 0-1; β is the dynamic correction coefficient, β= k1・L + k2・M +k3・P, k1, k2, and k3 are weighting coefficients, L is the normalized value of unit load, M is the normalized value of coal volatile matter, P is the unevenness of burner output, N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points; The output module is used to dynamically correct the eccentricity vector and the quantized value of the eccentricity in combination with the real-time operating conditions of the unit, and output the final quantized results of the eccentricity in the furnace; the formula for the dynamic correction is: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM); Where V'_total is the corrected eccentricity vector, D' is the corrected eccentricity quantification value, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, and ΔM is the coal volatile matter change rate.

[0008] Beneficial effects of the present invention This invention proposes a method and apparatus for quantitatively calculating the direction and degree of off-center combustion in a coal-fired power unit furnace. The method includes: collecting multi-source operating data of the coal-fired power unit furnace; constructing a three-dimensional temperature-flue gas concentration coupled field model of the furnace after preprocessing the multi-source data; extracting characteristic parameters of each monitoring zone of the furnace based on the coupled field model, and determining the direction of off-center combustion through vector synthesis; introducing a dynamic correction coefficient to construct a quantitative model of the degree of off-center combustion, and calculating the quantitative value of the degree of off-center combustion; dynamically correcting the results of the direction and degree of off-center combustion in combination with the unit's operating parameters, and outputting accurate quantitative results. This invention achieves accurate three-dimensional determination of the direction of off-center combustion in the furnace and multi-dimensional dynamic quantification of its degree, adapting to the variable operating conditions of the unit, effectively improving the combustion efficiency of the coal-fired power unit, and reducing NOx emissions. x The emission and local overheating risks in the furnace meet the requirements of green and low-carbon development and can be widely applied to the optimization of coal-fired boiler operation. Attached Figure Description

[0009] Figure 1 This is a flowchart of a preferred embodiment of the present invention for a method of quantitatively calculating the direction and degree of uneven combustion in a coal-fired power unit furnace; Figure 2 This is a structural diagram of a device for quantifying the direction and degree of uneven combustion in a coal-fired power unit furnace, according to a preferred embodiment of the present invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. For ease of explanation, only the parts related to the embodiments of this invention are shown. It should be understood that the specific embodiments described herein are merely for explaining this invention and are not intended to limit this invention.

[0011] This invention proposes a method and apparatus for quantitatively calculating the direction and degree of off-center combustion in a coal-fired power unit furnace. The method includes: collecting multi-source operating data of the coal-fired power unit furnace; constructing a three-dimensional temperature-flue gas concentration coupled field model of the furnace after preprocessing the multi-source data; extracting characteristic parameters of each monitoring zone of the furnace based on the coupled field model, and determining the direction of off-center combustion through vector synthesis; introducing a dynamic correction coefficient to construct a quantitative model of the degree of off-center combustion, and calculating the quantitative value of the degree of off-center combustion; dynamically correcting the results of the direction and degree of off-center combustion in combination with the unit's operating parameters, and outputting accurate quantitative results. This invention achieves accurate three-dimensional determination of the direction of off-center combustion in the furnace and multi-dimensional dynamic quantification of its degree, adapting to the variable operating conditions of the unit, effectively improving the combustion efficiency of the coal-fired power unit, and reducing NOx emissions. x The system addresses emissions and localized furnace overheating risks, aligns with green and low-carbon development requirements, and can be widely applied to the optimization of coal-fired boiler operation.

[0012] Figure 1 This is a flowchart of a preferred embodiment of the present invention for a method to quantitatively calculate the direction and degree of uneven combustion in a coal-fired power unit furnace; the method includes the following steps: S1. Collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. Specifically, in one embodiment of the present invention, the multi-source operational data includes: Real-time temperature data from at least 12 monitoring points evenly distributed across the upper, middle, and lower layers of the furnace inner wall (at least 4 points per layer, covering the left-right and front-back directions of the furnace) can be acquired via embedded thermocouples. The temperature measurement range is 0~1300℃ with an accuracy of ±1℃ and a sampling frequency of 10Hz, ensuring coverage of the entire furnace temperature distribution. For example, the coordinates of the monitoring points are (±1.5m, ±1.5m, 0m), (±1.5m, ±1.5m, 4m), and (±1.5m, ±1.5m, 8m) with the geometric center of the furnace as the origin. Flue gas composition data from at least eight monitoring points evenly distributed across the furnace outlet section can be collected using a flue gas analysis probe. The core components measured in the flue gas include O2, CO, and NO. x The measurement accuracy is ±0.1%, and the sampling frequency can be 5Hz, accurately reflecting the distribution of combustion products; The output data of the burner can be collected by the output transmitter installed in the pulverized coal pipeline of each burner. The measurement parameter is the pulverized coal flow rate, with an accuracy of ±0.1t / h and a sampling frequency of 1Hz. Coal quality data can be collected in real time by an online coal quality analyzer. The core parameters include volatile matter, ash content, and calorific value, with a measurement accuracy of ±0.5% and a sampling frequency of 1Hz. Unit load data can be collected through the unit's DCS system, in megawatts (MW), with an accuracy of ±1MW and a sampling frequency of 1Hz. All data collection is time-stamped synchronously to ensure time traceability. The layout of collection points, parameter selection, and subsequent data preprocessing (outlier removal, standardization, spatiotemporal alignment), furnace three-dimensional temperature-flue gas concentration coupled field modeling, and off-burning quantification are precisely matched to the needs, providing comprehensive and high-quality raw data support for subsequent steps.

[0013] S2. Preprocess the multi-source operating data; The preprocessing includes outlier removal, data standardization, and spatiotemporal alignment. In this embodiment of the invention, outlier removal can be performed using the 3σ criterion, box plot method, or Grubbs criterion; data standardization can be performed using the min-ma or z-score standardization method; and spatiotemporal alignment can be achieved by using linear interpolation, spline interpolation, or nearest neighbor interpolation to unify data from different sampling frequencies to a preset sampling frequency time dimension.

[0014] S3. Based on the preprocessed multi-source operating data, construct a three-dimensional coupled field model of furnace temperature and flue gas concentration. The coupled field model is based on the geometry of the furnace. The furnace is divided into several three-dimensional mesh units by the finite element method. Each mesh unit is assigned a weighting coefficient for temperature and flue gas concentration. The total number of three-dimensional mesh units is determined based on the furnace geometry, monitoring point density, and three-dimensional field modeling accuracy requirements (at least meeting the requirement of neighbor interpolation calculation for each monitoring point corresponding to each mesh unit). The division dimension of the three-dimensional mesh units must be adapted to the geometric proportions of the furnace length, width, and height to ensure full coverage of the furnace combustion space without modeling blind spots. In practical applications, the number of three-dimensional mesh units is 36-128. In one embodiment of the present invention, based on the actual geometric dimensions of the furnace (e.g., 12m long × 8m wide × 10m high), the furnace is divided into 64 three-dimensional mesh units (4×4×4) using the finite element method, with each mesh unit having a size of 3m×2m×2.5m. Using the geometric center of the coal-fired power unit's furnace as the origin of a three-dimensional coordinate system (point O, x=0, y=0), and the bottom of the furnace (furnace bottom) as the zero point of the z-axis (z=0), a three-dimensional coordinate system (such as a Cartesian coordinate system) is established based on the actual geometric dimensions of the furnace. x, y, and z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired power unit's furnace: x represents the left-right position of the furnace (geometric center is 0, right is positive, left is negative), y represents the front-back position of the furnace (geometric center is 0, front is positive, back is negative), and z represents the up-down position of the furnace (furnace bottom is 0, upward is positive). A three-dimensional temperature-flue gas concentration coupled field model is constructed: F(x,y,z)=α・T (x,y,z)+(1-α)・C(x,y,z); where F(x,y,z)... α is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient (ranging from 0.6 to 0.8, with temperature factors taking precedence), T(x,y,z) is the standardized temperature value of the grid cell (x,y,z) (calculated by interpolation from nearby monitoring points), and C(x,y,z) is the standardized flue gas concentration value of the grid cell (x,y,z) (calculated by interpolation from nearby monitoring points).

[0015] S4. Based on the aforementioned three-dimensional temperature-flue gas concentration coupled field model, extract the temperature deviation value and flue gas concentration deviation value of each grid cell, calculate the off-center burning direction vector using the vector synthesis method, and determine the three-dimensional direction of off-center burning in the furnace; including: S41, Calculate the temperature deviation and flue gas concentration deviation for each grid cell: ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; Where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. S42, calculate the deviation vector for each grid cell; Vᵢ= (ΔTᵢ・cosθᵢ,ΔTᵢ・sinθᵢ,ΔCᵢ); Where θᵢ is the azimuth angle of the mesh element in the xy plane (horizontal plane); S43, synthesize the deviation vectors of all grid cells to obtain the total deviation direction vector V_total=ΣVᵢ=(V_x,V_y, V_z), and determine the deviation direction based on the sign and absolute value of V_x, V_y, and V_z: If V_x > a preset threshold (e.g., 0.2), it is determined as right deviation; if V_x < -preset threshold, it is determined as left deviation; If V_y > a preset threshold, it is determined as front deviation; if V_y < -preset threshold, it is determined as rear deviation; If V_z > a preset threshold, it is determined as upper deviation; if V_z < -preset threshold, it is determined as lower deviation; If the absolute values of a plurality of direction vectors are all greater than the preset threshold, a composite deviation combustion direction (such as right-front-upper deviation) is determined.

[0016] Wherein, V_x, V_y and V_z are respectively components of the total deviation combustion direction vector V_total on the x-axis, y-axis and z-axis of the three-dimensional coordinate system of the furnace: V_x represents the overall deviation combustion trend in the left-right direction of the furnace (positive on the right and negative on the left), V_y represents the overall deviation combustion trend in the front-rear direction of the furnace (positive on the front and negative on the rear), and V_z represents the overall deviation combustion trend in the up-down direction of the furnace (positive on the upper and negative on the lower); S5. Construct a quantitative model of deviation combustion degree, and calculate a quantitative value of the deviation combustion degree; In the embodiment of the present invention, the calculation formula of the quantitative model of deviation combustion degree may be: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Wherein, D is the quantitative value of deviation combustion degree, with a value range of 0-1. In some specific implementations, D≥0.3 is determined as mild deviation combustion, 0.3<D≤0.6 is moderate deviation combustion, and D>0.6 is severe deviation combustion; β is a dynamic correction coefficient, β= k1・L + k2・M+ k3・P; k1, k2 and k3 are weight coefficients, L is the normalized value of unit load (actual unit load / rated load), M is the normalized value of coal volatile matter (actual volatile matter / designed volatile matter), P is the burner output unevenness (Σ|Qᵢ - Q_avg| / Q_avg, Qᵢ is the output of a single burner, Q_avg is the average output), N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points.

[0017] S6. Dynamically correct the deviation combustion direction vector and the quantitative value of deviation combustion degree in combination with the real-time working condition change of the unit, and output the final quantitative result of the furnace deviation combustion direction and degree.

[0018] In the embodiment of the present invention, the formula for the dynamic correction may be: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM); Wherein, V'_total is the corrected combustion direction vector, D' is the corrected quantified value of combustion degree, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, ΔL=(L_t - L_t-1) / L_t-1, where t is the current time and t-1 is the previous time (e.g., the time interval between t and t-1 is 0.1 seconds, consistent with the 10Hz sampling frequency), L_t is the actual unit load at the current time, and L_t-1 is the actual unit load at the previous time. All data are from the unit's DCS system; ΔM is the coal volatile matter change rate, ΔM=(M_t - M_t-1) / M_t-1, where M_t is the actual volatile matter of the coal at the current time and M_t-1 is the actual volatile matter of the coal at the previous time. All data are from the online coal quality analyzer. Corresponding to the quantitative calculation method for the direction and degree of uneven combustion in the furnace of a coal-fired power unit described in the above embodiment, Figure 2 This diagram illustrates a structural block diagram of a device for quantifying the direction and degree of uneven combustion in a coal-fired power unit furnace, as provided in an embodiment of this application. For ease of explanation, only the parts relevant to the embodiment of this application are shown. The device includes:

[0019] The data acquisition module is used to collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. The preprocessing module is used to preprocess the multi-source running data; The 3D field modeling module is used to construct a 3D temperature-flue gas concentration coupled field model of the furnace based on preprocessed multi-source operating data. This coupled field model is based on the furnace geometry, dividing the furnace into several 3D mesh elements using the finite element method, with each mesh element assigned weight coefficients for temperature and flue gas concentration. The construction of the 3D temperature-flue gas concentration coupled field model of the furnace is as follows: F(x,y,z)=α・T(x,y,z)+(1-α)・C(x,y,z); Where F(x,y,z) is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient, T(x,y,z) is the normalized temperature value of the grid cell (x,y,z), C(x,y,z) is the normalized flue gas concentration value of the grid cell (x,y,z), and x, y, z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired unit furnace; The direction determination module is used to extract the temperature deviation value and flue gas concentration deviation value of each grid cell based on the three-dimensional temperature-flue gas concentration coupled field model, calculate the off-center burning direction vector through vector synthesis method, and determine the three-dimensional direction of off-center burning in the furnace; including: Calculate the temperature deviation and flue gas concentration deviation for each grid cell; ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. Calculate the deviation vector Vᵢ for each mesh element; Vᵢ = (ΔTᵢ・cosθᵢ, ΔTᵢ・sinθᵢ, ΔCᵢ); where θᵢ is the azimuth angle of the mesh element in the xy plane; The deviation vectors of all grid cells are synthesized to obtain the total deviation direction vector V_total. The deviation direction is determined based on the sign and absolute value of V_x, V_y, and V_z. V_total=ΣVᵢ=(V_x,V_y, V_z), where V_X, V_y, and V_z are the components of the total off-center burning direction vector V_total on the x-axis, y-axis, and z-axis of the three-dimensional coordinate system of the furnace, respectively. V_X represents the overall off-center burning trend in the left-right direction of the furnace, V_y represents the overall off-center burning trend in the front-back direction of the furnace, and V_z represents the overall off-center burning trend in the up-down direction of the furnace. The degree quantification module is used to construct a degree quantification model for uneven burning and calculate the degree quantification value for uneven burning; the calculation formula for the degree quantification model for uneven burning is as follows: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Where D is the quantitative value of the degree of uneven burning, with a value range of 0-1; β is the dynamic correction coefficient, β= k1・L + k2・M +k3・P, k1, k2, and k3 are weighting coefficients, L is the normalized value of unit load, M is the normalized value of coal volatile matter, P is the unevenness of burner output, N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points; The output module is used to dynamically correct the eccentricity vector and the quantified value of the eccentricity degree based on the real-time operating conditions of the unit, and output the final quantified results of the eccentricity direction and degree of the furnace. The formula for the dynamic correction is: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM);

[0020] Where V'_total is the corrected eccentricity vector, D' is the corrected eccentricity quantification value, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, and ΔM is the coal volatile matter change rate.

[0021] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by program instructions and related hardware. The program can be stored in a computer-readable storage medium, such as ROM, RAM, disk, optical disk, etc.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired power unit, characterized in that, The method includes: Collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. The multi-source operational data is preprocessed; Based on the preprocessed multi-source operating data, a three-dimensional temperature-flue gas concentration coupled field model of the furnace is constructed. The coupled field model is based on the geometry of the furnace and divides the furnace into several three-dimensional grid units using the finite element method. Each grid unit is assigned a weighting coefficient for temperature and flue gas concentration. The constructed three-dimensional temperature-flue gas concentration coupled field model of the furnace is as follows: F(x,y,z)=α・T(x,y,z)+(1-α)・C(x,y,z); Where F(x,y,z) is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient, T(x,y,z) is the normalized temperature value of the grid cell (x,y,z), C(x,y,z) is the normalized flue gas concentration value of the grid cell (x,y,z), and x, y, z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired unit furnace; Based on the aforementioned three-dimensional temperature-flue gas concentration coupled field model, the temperature deviation value and flue gas concentration deviation value of each grid cell are extracted. The off-center combustion direction vector is calculated using a vector synthesis method to determine the three-dimensional direction of off-center combustion in the furnace; including: Calculate the temperature deviation and flue gas concentration deviation for each grid cell; ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. Calculate the deviation vector Vᵢ for each mesh element; Vᵢ = (ΔTᵢ・cosθᵢ, ΔTᵢ・sinθᵢ, ΔCᵢ); where θᵢ is the azimuth angle of the mesh element in the xy plane; The deviation vectors of all grid cells are synthesized to obtain the total deviation direction vector V_total. The deviation direction is determined based on the sign and absolute value of V_x, V_y, and V_z. V_total=ΣVᵢ=(V_x,V_y, V_z), where V_x, V_y, and V_z are the components of the total off-center burning direction vector V_total on the x-axis, y-axis, and z-axis of the three-dimensional coordinate system of the furnace, respectively. V_x represents the overall off-center burning trend in the left-right direction of the furnace, V_y represents the overall off-center burning trend in the front-back direction of the furnace, and V_z represents the overall off-center burning trend in the up-down direction of the furnace. Construct a quantitative model for the degree of uneven burning and calculate the quantitative value of the degree of uneven burning; The calculation formula for the quantification model of the degree of uneven burning is as follows: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Where D is the quantitative value of the degree of uneven burning, with a value range of 0-1; β is the dynamic correction coefficient, β= k1・L + k2・M + k3・P, k1, k2, and k3 are weighting coefficients, L is the normalized value of unit load, M is the normalized value of coal volatile matter, P is the unevenness of burner output, N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points; By combining the real-time changes in the unit's operating conditions, the quantification values ​​of the burn-off direction vector and the burn-off degree are dynamically corrected, and the final quantification results of the burn-off direction and degree in the furnace are output. The formula for dynamic correction is: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM); Where V'_total is the corrected eccentricity vector, D' is the corrected eccentricity quantification value, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, and ΔM is the coal volatile matter change rate.

2. The method for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired power unit as described in claim 1, characterized in that, The multi-source operational data includes: Real-time temperature data from at least 12 monitoring points evenly distributed on the upper, middle, and lower layers of the furnace inner wall; Flue gas composition data from at least eight monitoring points evenly distributed across the furnace outlet cross-section, including O2, CO, and NO. x ; Burner output data includes pulverized coal flow rate; Coal quality data includes volatile matter, ash content, and calorific value.

3. The method for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired power unit as described in claim 1, characterized in that, The preprocessing includes outlier removal, data standardization, and spatiotemporal alignment. Outlier removal uses the 3σ criterion, box plot method, or Grubbs criterion. Data standardization uses the min-ma or z-score standardization method. Spatiotemporal alignment unifies data with different sampling frequencies to the preset sampling frequency time dimension through linear interpolation, spline interpolation, or nearest neighbor interpolation.

4. The method for quantitatively calculating the direction and degree of uneven combustion in the furnace of a coal-fired power unit as described in claim 1, characterized in that, The method for determining the direction of partial burning based on the sign and absolute value of V_x, V_y, and V_z is as follows: If V_x > preset threshold, it is determined to be right skewed; if V_x <- preset threshold, it is determined to be left skewed. If V_y > preset threshold, it is determined to be forward bias; if V_y <- preset threshold, it is determined to be backward bias. If V_z > preset threshold, it is determined to be upward biased; if V_z <- preset threshold, it is determined to be downward biased. If the absolute values ​​of multiple direction vectors are all greater than the preset threshold, it is determined to be a composite biased burning direction.

5. A device for quantitatively calculating the direction and degree of uneven combustion in a coal-fired power unit furnace, characterized in that, The device includes: The data acquisition module is used to collect multi-source operating data of the coal-fired unit furnace; the multi-source operating data includes real-time temperature data of several monitoring points in the furnace, flue gas composition data of several monitoring points, burner output data, coal quality data and unit load data. The preprocessing module is used to preprocess the multi-source running data; The 3D field modeling module is used to construct a 3D temperature-flue gas concentration coupled field model of the furnace based on preprocessed multi-source operating data. This coupled field model is based on the furnace geometry, dividing the furnace into several 3D mesh elements using the finite element method, with each mesh element assigned weight coefficients for temperature and flue gas concentration. The construction of the 3D temperature-flue gas concentration coupled field model of the furnace is as follows: F(x,y,z)=α・T(x,y,z)+(1-α)・C(x,y,z); Where F(x,y,z) is the coupled field value of the grid cell (x,y,z), α is the weighting coefficient, T(x,y,z) is the normalized temperature value of the grid cell (x,y,z), C(x,y,z) is the normalized flue gas concentration value of the grid cell (x,y,z), and x, y, z are the coordinate values ​​of the three-dimensional spatial coordinate system of the coal-fired unit furnace; The direction determination module is used to extract the temperature deviation value and flue gas concentration deviation value of each grid cell based on the three-dimensional temperature-flue gas concentration coupled field model, calculate the off-center burning direction vector through vector synthesis method, and determine the three-dimensional direction of off-center burning in the furnace; including: Calculate the temperature deviation and flue gas concentration deviation for each grid cell; ΔTᵢ = T(x,y,z)-T_avg, ΔCᵢ = C(x,y,z)-C_avg; where ΔTᵢ is the deviation between the grid cell temperature and the furnace average temperature, ΔCᵢ is the deviation between the grid cell flue gas concentration and the furnace average flue gas concentration, and T_avg and C_avg are the furnace average temperature and average flue gas concentration, respectively. Calculate the deviation vector Vᵢ for each mesh element; Vᵢ = (ΔTᵢ・cosθᵢ, ΔTᵢ・sinθᵢ, ΔCᵢ); where θᵢ is the azimuth angle of the mesh element in the xy plane; The deviation vectors of all grid cells are synthesized to obtain the total deviation direction vector V_total. The deviation direction is determined based on the sign and absolute value of V_x, V_y, and V_z. V_total=ΣVᵢ=(V_x,V_y, V_z), where V_x, V_y, and V_z are the components of the total off-center burning direction vector V_total on the x-axis, y-axis, and z-axis of the three-dimensional coordinate system of the furnace, respectively. V_x represents the overall off-center burning trend in the left-right direction of the furnace, V_y represents the overall off-center burning trend in the front-back direction of the furnace, and V_z represents the overall off-center burning trend in the up-down direction of the furnace. The degree quantification module is used to construct a degree quantification model for uneven burning and calculate the degree quantification value for uneven burning; the calculation formula for the degree quantification model for uneven burning is as follows: D=β・(Σ|ΔTᵢ| / N_T + Σ|ΔCᵢ| / N_C); Where D is the quantitative value of the degree of uneven burning, with a value range of 0-1; β is the dynamic correction coefficient, β= k1・L + k2・M + k3・P, k1, k2, and k3 are weighting coefficients, L is the normalized value of unit load, M is the normalized value of coal volatile matter, P is the unevenness of burner output, N_T is the number of temperature monitoring points, and N_C is the number of flue gas concentration monitoring points; The output module is used to dynamically correct the eccentricity vector and the quantized value of the eccentricity in combination with the real-time operating conditions of the unit, and output the final quantized results of the eccentricity in the furnace; the formula for the dynamic correction is: V'_total=V_total・(1+ε・ΔL); D'=D・(1+δ・ΔM); Where V'_total is the corrected eccentricity vector, D' is the corrected eccentricity quantification value, ε is the load correction coefficient, δ is the coal quality correction coefficient, ΔL is the unit load change rate, and ΔM is the coal volatile matter change rate.

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