System and method for controlling parameters of denitration inlet and air preheater outlet of coal-fired unit

Abstract

The invention relates to a coal-fired unit denitration inlet and air preheater outlet parameter control system and method, and the system comprises a denitration inlet measurement module which is used for carrying out the uniform sampling of flue gas at a plurality of flue gas sampling ports preset on a plurality of measurement supports, and carrying out the measurement coupling of a temperature field; the air preheater outlet measuring module is used for obtaining temperature field data and oxygen field data at the section of an outlet flue according to the temperature field and the oxygen distribution; the data processing and analyzing module is used for analyzing flue gas components at a denitration inlet of the coal-fired unit and an outlet of an air preheater; and the control execution module is used for adjusting the operation parameters of the denitration system according to the temperature meeting the preset lowest point condition and adjusting the operation parameters of the air preheater. According to the application, high-precision measurement of temperature fields and flue gas components at a denitration inlet and an air pre-heater outlet is realized, and safe, efficient and environment-friendly operation of a coal-fired unit under a novel power system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of operation monitoring and optimal control of coal-fired generating units, and in particular to a coal-fired unit denitration inlet and air preheater outlet parameter control system and method. BACKGROUND

[0002] Under the development trend of new power systems, large-scale new energy is connected to the power grid, and coal-fired units need to undertake more peak regulation tasks, frequently operating in long-term peak and deep peak regulation conditions, and showing peak-valley prominent operation characteristics. This operation mode brings many challenges to coal-fired units, among which the problems of wide-load denitration, air preheater blockage and leakage rate are particularly prominent. In related technologies, the instantaneous emission at the flue cross section can be calculated according to the flue gas parameters, the deviation coefficient is obtained by comparing the instantaneous emission under different loads with the preset unit emission in the database, and the real-time data of carbon emission monitoring of the coal-fired unit is determined according to the deviation coefficient.

[0003] However, in the related art, the denitration efficiency is strongly dependent on the denitration inlet flue gas temperature in the operation of the denitration system, the existing measuring points are difficult to fully and accurately grasp the flue gas temperature distribution, the minimum point of the denitration inlet temperature cannot be effectively obtained, and the stable operation of the denitration system under wide-load conditions cannot be guaranteed; the temperature measuring points at the air preheater outlet are insufficient, the temperature field distribution cannot be fully presented, abnormal conditions such as air preheater blockage and air leakage cannot be timely discovered through temperature changes, the health status of the air preheater cannot be fully evaluated by relying on a single temperature or oxygen index, sufficient basis cannot be provided for operation adjustment and maintenance, and improvement is urgently needed. SUMMARY The application provides a coal-fired unit denitration inlet and air preheater outlet parameter control system and method to solve the problem that the denitration efficiency is highly dependent on the denitration inlet flue gas temperature in terms of denitration system operation. When the unit is in low-load deep peak shaving, if the denitration inlet flue gas temperature is lower than the lower limit of the catalyst activity requirement, the denitration will fail, and the ammonia escape amount will increase significantly. The escaped ammonia reacts with sulfur trioxide in the flue gas to generate ammonium bisulfate, which adheres to the surface of the air preheater, thereby causing the air preheater to be blocked. At the same time, the current denitration inlet arrangement has a small number of temperature measuring points, and the temperature distribution in the cross section of the flue gas in this area is uneven. The existing measuring points cannot fully and accurately grasp the flue gas temperature distribution, cannot effectively obtain the minimum point of the denitration inlet temperature, and cannot guarantee the stable operation of the denitration system under wide load conditions. For the air preheater, under low load conditions, the exhaust gas temperature decreases, and the comprehensive cold end temperature of the air preheater decreases, which will exacerbate the blocking and corrosion of the cold end of the air preheater. Moreover, the temperature measuring points at the outlet of the air preheater are insufficient, and the temperature field distribution cannot be fully presented, making it difficult to discover abnormal conditions such as air preheater blocking and air leakage in time through temperature changes. In addition, it is difficult to fully evaluate the health status of the air preheater by relying on a single temperature or oxygen index, and it is difficult to provide sufficient basis for operation adjustment and maintenance, etc.

[0004] The first aspect embodiment of the present application provides a coal-fired unit denitration inlet and air preheater outlet parameter control system, comprising: a denitration inlet measurement module, configured to arrange a plurality of measurement supports at the flue cross section of the coal-fired unit denitration inlet, uniformly sample flue gas at a flue gas sampling port pre-set on the plurality of measurement supports, and measure the temperature field at a temperature thermocouple probe pre-set on the plurality of measurement supports, to generate measurement data of the coal-fired unit denitration inlet; an air preheater outlet measurement module, configured to arrange the plurality of measurement supports at the outlet flue cross section of the air preheater, measure the temperature field at the outlet flue cross section by using the temperature thermocouple probe pre-set on the plurality of measurement supports, and extract flue gas by using the flue gas sampling port pre-set on the plurality of measurement supports, measure the oxygen field distribution at the outlet flue cross section by a mixing header, to obtain temperature field data and oxygen field data at the outlet flue cross section according to the temperature field and the oxygen field distribution; a data processing and analysis module, configured to calculate the temperature at which the coal-fired unit denitration inlet meets a preset minimum point condition based on the measurement data, analyze the flue gas composition of the coal-fired unit denitration inlet in the mixing header, to determine the distribution of nitrogen oxides at the coal-fired unit denitration inlet, construct a comprehensive judgment factor based on the temperature field data and the oxygen field data obtained by the air preheater outlet measurement module, and determine the blockage condition, air leakage position and air leakage degree of the air preheater according to the comprehensive judgment factor; and a control execution module, configured to adjust the operating parameters of the denitration system according to the temperature at which the coal-fired unit denitration inlet meets the preset minimum point condition, to optimize the operation of the denitration system, and adjust the operating parameters of the air preheater according to the blockage condition, air leakage position and air leakage degree of the air preheater, to optimize the operation of the air preheater.

[0005] Optionally, in an embodiment of the present application, the denitration inlet measurement module comprises: a temperature field and flue gas composition measurement unit, configured to obtain the flue gas temperature and flue gas composition information at the flue cross section of the coal-fired unit denitration inlet; and a flue gas analysis unit, configured to mix the flue gas of each branch pipe in the mixing header after multi-point sampling, to analyze the flue gas composition of the flue gas temperature and the flue gas composition information, to determine the flue gas composition data of the coal-fired unit denitration inlet, and generate the measurement data of the denitration inlet according to the flue gas composition data.

[0006] Optionally, in an embodiment of the present application, the denitration inlet measurement module further comprises a sampling pipeline, the sampling pipeline comprising a flow regulating valve and a branch pipe, wherein the flow regulating valve is used to adjust the flue gas flow of the coal-fired unit denitration inlet or close the branch according to the target measurement requirement, and the branch pipe uses a double-path setting, and in the case that the first branch meets a preset fault condition, the second branch carries out single-point flue gas component analysis according to the actual requirement to obtain the oxygen content field distribution.

[0007] Optionally, in an embodiment of the present application, the data processing and analysis module comprises a temperature field analysis unit, which is used to construct a temperature field distribution model according to the temperature data and calculate the temperature at which the coal-fired unit denitration inlet meets a preset minimum point condition; a flue gas component analysis unit, which is used to process the mixed flue gas component data and single-point analysis data in the mixing box after mixing to obtain target data, and determine the nitrogen oxide distribution at the coal-fired unit denitration inlet based on the target data and the temperature data of the temperature field; and an air preheater health state evaluation unit, which is used to construct the comprehensive judgment factor according to the temperature at which the coal-fired unit denitration inlet meets the preset minimum point condition and the nitrogen oxide distribution, determine the abnormal state of the air preheater according to the comprehensive judgment factor, determine the blockage condition and air leakage position of the air preheater based on the abnormal state, actual temperature and oxygen content distribution abnormal area, and determine the air leakage degree according to the outlet temperature and oxygen content corresponding relationship of the air preheater.

[0008] The second aspect embodiment of the application provides a coal-fired unit denitration inlet and air preheater outlet parameter control method, including the following steps: after arranging a plurality of measuring supports at the flue section of the coal-fired unit denitration inlet, uniformly sampling flue gas from the flue gas sampling ports prearranged on the plurality of measuring supports, and coupling temperature field measurement of the temperature thermocouple probes prearranged on the plurality of measuring supports, measurement data of the coal-fired unit denitration inlet is generated; after arranging the plurality of measuring supports at the outlet flue section of the air preheater, measuring the temperature field at the outlet flue section by using the temperature thermocouple probes prearranged on the plurality of measuring supports, and extracting flue gas by using the flue gas sampling ports prearranged on the plurality of measuring supports, the oxygen field distribution at the outlet flue section is measured by a mixing header, so that the temperature field data and the oxygen field data at the outlet flue section are obtained according to the temperature field and the oxygen field distribution; the temperature at which the coal-fired unit denitration inlet meets a preset minimum point condition is calculated based on the measurement data, and the flue gas composition of the coal-fired unit denitration inlet is analyzed in the mixing box to determine the distribution of nitrogen oxides at the coal-fired unit denitration inlet, a comprehensive judgment factor is constructed based on the temperature field data and the oxygen field data obtained by the air preheater outlet measurement module, and the blockage condition, the air leakage position and the air leakage degree of the air preheater are determined according to the comprehensive judgment factor; the operating parameters of the denitration system are adjusted according to the temperature meeting the preset minimum point condition, so as to optimize the operation of the denitration system, and the operating parameters of the air preheater are adjusted according to the blockage condition, the air leakage position and the air leakage degree of the air preheater, so as to optimize the operation of the air preheater.

[0009] Optionally, in an embodiment of the application, the uniformly sampling flue gas from the flue gas sampling ports prearranged on the plurality of measuring supports, and coupling temperature measurement of at least one temperature thermocouple probe prearranged on the plurality of measuring supports to generate measurement data of the coal-fired unit denitration inlet includes: obtaining flue gas temperature and flue gas composition information at the flue section of the coal-fired unit denitration inlet; after the mixing box is arranged, the flue gas of each branch pipe is mixed in the mixing box after multi-point sampling, so as to analyze the flue gas composition, determine flue gas composition data of the coal-fired unit denitration inlet, and generate measurement data of the denitration inlet according to the flue gas composition data.

[0010] Optionally, in an embodiment of the application, the uniformly sampling flue gas from the flue gas sampling ports prearranged on the plurality of measuring supports further includes: in the case that the first branch meets a preset fault condition, the second branch performs single-point flue gas composition analysis according to actual needs to obtain the oxygen field distribution.

[0011] Optionally, in an embodiment of the present application, the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition is calculated based on the measurement data, and the composition of flue gas at the denitration inlet of the coal-fired generating unit is analyzed in the mixing box to determine the distribution of nitrogen oxides at the denitration inlet of the coal-fired generating unit, the comprehensive judgment factor is constructed based on the temperature field data and the oxygen content field data obtained by the air preheater outlet measurement module, and the blockage condition, the air leakage position and the air leakage degree of the air preheater are determined according to the comprehensive judgment factor, including: a temperature field distribution model is constructed according to the temperature field data, and the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition is calculated according to the temperature field distribution model; the mixed flue gas composition data and the single-point analysis data in the mixing box are processed to obtain target data, and the distribution of nitrogen oxides at the denitration inlet of the coal-fired generating unit is determined based on the target data and the temperature field data; the comprehensive judgment factor is constructed according to the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition and the distribution of nitrogen oxides, the abnormal state of the air preheater is determined according to the comprehensive judgment factor, the blockage condition and the air leakage position of the air preheater are determined based on the abnormal state, the actual temperature and the oxygen content distribution abnormal area, and the air leakage degree is determined according to the outlet temperature and oxygen content corresponding relationship of the air preheater.

[0012] The third aspect embodiment of the present application provides an electronic device, including: a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the program to realize the coal-fired generating unit denitration inlet and air preheater outlet parameter control method as described in the above embodiments.

[0013] The fourth aspect embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the coal-fired generating unit denitration inlet and air preheater outlet parameter control method as described above.

[0014] The embodiments of the present application include a denitration inlet measurement module, an air preheater outlet measurement module, a data processing and analysis module, and a control execution module, which can realize high-precision measurement of the temperature field and flue gas composition at the denitration inlet and the air preheater outlet through innovative measurement systems and methods, provide reliable data support for wide-load denitration control and air preheater health management, and ensure the safe, efficient and environmentally friendly operation of the coal-fired generating unit under the new power system. Therefore, the problems of insufficient temperature measurement points, incomplete temperature field measurement, single flue gas composition measurement, inability to effectively realize wide-load denitration precise control, difficulty in accurately evaluating the health status of the air preheater and optimizing the adjustment in the related art are solved.

[0015] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and / or additional aspects and advantages of the application will become apparent and be well understood from the following description, taken in conjunction with the drawings, wherein: Figure 1 A structural schematic diagram of a coal-fired unit denitration inlet and air preheater outlet parameter control system according to an embodiment of the application; Figure 2 A schematic diagram of a flue gas internal measurement support arrangement position according to an embodiment of the application; Figure 3 A schematic diagram of an A-A / B-B cross-section flue gas parameter analysis system arrangement according to an embodiment of the application; Figure 4 A schematic diagram of a measurement support internal structure according to an embodiment of the application; Figure 5 A flowchart of a coal-fired unit denitration inlet and air preheater outlet parameter control method according to an embodiment of the application; Figure 6 A structural schematic diagram of an electronic device according to an embodiment of the application. DETAILED DESCRIPTION

[0017] Embodiments of the application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals are used throughout the figures to refer to same or like components. The embodiments described below are illustrative of the application and are not intended to be limiting.

[0018] A coal-fired unit denitration inlet and air preheater outlet parameter control system and method according to an embodiment of the present application is described below with reference to the accompanying drawings. In view of the problems of insufficient temperature measuring points at the denitration inlet and air preheater outlet of the coal-fired unit, incomplete temperature field measurement, single flue gas composition measurement, inability to effectively achieve precise control of denitration over a wide load range, and difficulty in accurately assessing the health status of the air preheater and performing optimal adjustment in the related art, the present application provides a coal-fired unit denitration inlet and air preheater outlet parameter monitoring system and control method. In the system, a denitration inlet measurement module, an air preheater outlet measurement module, a data processing and analysis module, and a control execution module are included. High-precision measurement of the temperature field at the denitration inlet and air preheater outlet and the flue gas composition can be achieved through innovative measurement systems and methods, providing reliable data support for wide-load denitration control and air preheater health management, and ensuring the safe, efficient, and environmentally friendly operation of coal-fired units in the new power system. Thus, the problems of insufficient temperature measuring points at the denitration inlet and air preheater outlet of the coal-fired unit, incomplete temperature field measurement, single flue gas composition measurement, inability to effectively achieve precise control of denitration over a wide load range, and difficulty in accurately assessing the health status of the air preheater and performing optimal adjustment in the related art are solved.

[0019] Specifically, Figure 1 A structure diagram of a coal-fired unit denitration inlet and air preheater outlet parameter control system according to an embodiment of the present application is shown.

[0020] As Figure 1 shown, the coal-fired unit denitration inlet and air preheater outlet parameter control system includes a denitration inlet measurement module 100, an air preheater outlet measurement module 200, a data processing and analysis module 300, and a control execution module 400.

[0021] Specifically, the denitration inlet measurement module 100 is configured to arrange multiple measurement supports at the flue cross section of the denitration inlet of the coal-fired unit, uniformly sample the flue gas at the pre-set flue gas sampling ports on the multiple measurement supports, and couple the temperature field measurement of the pre-set temperature thermocouple probes on the multiple measurement supports to generate measurement data of the denitration inlet of the coal-fired unit.

[0022] It can be understood that the denitration inlet measurement module 100 in the present embodiment can be a monitoring device at the inlet of the coal-fired unit denitration system.

[0023] In actual implementation, the embodiment of the present application can arrange a measurement system. Taking a 600 MW coal-fired unit as an example, 7*10 measurement supports are arranged on the cross section (4m*6m) of the flue at the inlet of the denitration system according to the Chebyshev grid method, and the supports are made of wear-resistant steel and have a spacing of about 0.6m*0.6m. One flue gas sampling port and one temperature thermocouple probe are arranged on each support, and the flue gas sampling port and the temperature thermocouple probe are arranged alternately to realize the coupling of uniform flue gas sampling and temperature measurement. The branch pipes of the supports are arranged by double-path DN25 stainless steel pipes, and an electric flow regulating valve (with a shut-off function) is installed before the branch pipes are connected to the header. The header is connected to a mixing box, and the mixing box is designed in a parallel structure and can realize mixed measurement and single-point measurement by switching valves.

[0024] The embodiment of the present application can arrange measurement supports, temperature thermocouple probes, oxygen sensors, flow regulating valves, flue gas sampling pipelines and mixing boxes and other equipment on the cross section of the flue at the inlet of the denitration system and the cross section of the flue at the outlet of the air preheater according to the Chebyshev grid method, and debug and initialize the equipment, thereby providing support for more comprehensive and accurate measurement of the temperature field distribution of the cross section of the flue at the inlet of the denitration system and the cross section of the flue at the outlet of the air preheater, effectively obtaining the lowest point of the temperature at the inlet of the denitration system, providing reliable data for wide-load denitration control, ensuring the stable operation of the denitration system under low-load conditions, and reducing ammonia escape. Optionally, in an embodiment of the present application, the denitration inlet measurement module 100 includes: a temperature field and flue gas component measurement unit for obtaining flue gas temperature and flue gas component information at the cross section of the flue at the inlet of the denitration system of the coal-fired unit; and a flue gas analysis unit for mixing the flue gas sampled from the branch pipes in the mixing box after the mixing box is arranged, performing flue gas component analysis on the flue gas temperature and the flue gas component information, determining flue gas component data of the inlet of the denitration system of the coal-fired unit, and generating measurement data of the inlet of the denitration system according to the flue gas component data.

[0025] In the embodiment of the present application, the following are included: (1) Temperature field and flue gas component measurement structure: a plurality of measurement supports are arranged on the cross section of the flue at the inlet of the denitration system according to the Chebyshev grid method, and the measurement supports are made of wear-resistant steel to resist long-term flue gas erosion and wear. The measurement supports are interconnected, and each support is provided with a flue gas sampling port and a temperature thermocouple probe. The arrangement of the flue gas sampling port and the temperature thermocouple probe realizes the coupling design of uniform flue gas sampling and grid method temperature measurement, and can accurately obtain flue gas temperature and component information at different positions of the cross section of the flue.

[0026] (2) Flue gas analysis device: a mixing box is arranged, flue gas of each branch pipe is mixed in the mixing box after multi-point sampling, flue gas component analysis is performed, and flue gas component data of the whole denitration inlet are obtained. Meanwhile, two mixing boxes are designed in a parallel structure, one is used for measuring the parameters of the mixed flue gas, and the other can be used to measure the flue gas component of a certain point or a certain area in cooperation with a shut-off valve if necessary, so as to provide more accurate data for optimization of ammonia injection of the denitration system.

[0027] Optionally, in an embodiment of the present application, the denitration inlet measurement module 100 further comprises: a sampling pipeline, the sampling pipeline comprising a flow regulating valve and a branch pipe, wherein the flow regulating valve is used to adjust the flue gas flow of the denitration inlet of the coal-fired unit or to close the branch according to the target measurement requirement, and the branch pipe is provided with a double pipeline, which is used to perform single-point flue gas component analysis according to the actual requirement to obtain the oxygen content field distribution in the case that the first branch satisfies the preset fault condition.

[0028] It can be understood that the flow regulating valve in the embodiment of the present application is installed in the sampling pipeline, and is used to accurately adjust the flue gas flow entering the analysis system.

[0029] In the embodiment of the present application, the sampling pipeline design can be included: the branch pipe of each measurement support is arranged with a flow regulating valve before being connected to the header tank, the flow regulating valve has a shut-off function, and can adjust the flue gas flow or close a certain branch according to the measurement requirement. The branch pipe is provided with a double pipeline, which can ensure the reliability of the measurement system, and when one pipeline fails, the other pipeline can still work normally. The other pipeline is designed to enable each measurement point to be measured independently, and can also be used as a backup. The embodiment of the present application has the following sampling design advantages: coupling design of flue gas sampling and smoke temperature sampling, double pipeline arrangement of the branch pipe, and setting of the flow regulating valve, which can ensure the measurement accuracy, improve the reliability and flexibility of the measurement system, reduce the wear of the measurement element, and prolong the service life of the equipment.

[0030] The air preheater outlet measurement module 200 is used to measure the temperature field at the outlet flue cross section of the air preheater by using the temperature thermocouple probes prearranged on the plurality of measurement supports after arranging the plurality of measurement supports at the outlet flue cross section of the air preheater, and measure the oxygen content field distribution at the outlet flue cross section by using the flue gas sampling ports prearranged on the plurality of measurement supports, so as to obtain the temperature field data and the oxygen content field data at the outlet flue cross section according to the temperature field and the oxygen content field distribution.

[0031] In the actual execution process, the embodiment of the present application can include: (1) Temperature field and oxygen content measurement structure: at the outlet flue cross section (size 4m*6m) of the air preheater, a plurality of measurement supports are arranged according to the Chebyshev grid method, such as 6*9 measurement supports, the support material is wear-resistant steel, 1 temperature thermocouple probe and 1 oxygen content sensor are arranged on each support, the temperature field at the outlet flue cross section is measured by using the temperature thermocouple probe prearranged on the plurality of measurement supports, and the oxygen content value at the outlet flue cross section is measured by using the flue gas sampling port prearranged on the plurality of measurement supports.

[0032] (2) Data transmission and processing: the temperature and oxygen content data collected by the temperature thermocouple probe and the oxygen content sensor, and the opening data of the flow regulating valve are transmitted to the data acquisition card through 4-20mA signal, and the data acquisition card transmits the data to the data processing and analysis server through industrial Ethernet. The data collected by the temperature thermocouple probe and the oxygen content sensor is transmitted to the data processing and analysis module 300, which is used to analyze the temperature field and oxygen content distribution at the outlet of the air preheater, and obtain the temperature data and oxygen content data. The embodiment of the present application can collect the temperature data and oxygen content data of the denitration inlet and the outlet flue cross section of the air preheater in real time through the temperature thermocouple probe and the oxygen content sensor; the flow regulating valve adjusts the flue gas flow of each branch pipe, the flue gas is mixed in the mixing box after multi-point sampling or single-point sampling, and the flue gas composition data is collected, so that the flue gas composition measurement innovation is carried out, the mixed measurement and single-point measurement functions are possessed, the flue gas composition information of the whole flue cross section can be obtained, and detailed analysis can be carried out on the specific position, so as to provide accurate data for the ammonia injection optimization of the denitration system, improve the denitration efficiency, and reduce the operation cost. The data processing and analysis module 300 is used to calculate the temperature of the denitration inlet of the coal-fired unit meeting the preset minimum point condition based on the measurement data, analyze the flue gas composition at the denitration inlet of the coal-fired unit in the mixing box, determine the distribution of nitrogen oxides at the denitration inlet of the coal-fired unit, construct a comprehensive judgment factor based on the temperature field data and the oxygen content field data obtained by the air preheater outlet measurement module, and determine the blockage of the air preheater, the air leakage position and the air leakage degree according to the comprehensive judgment factor.

[0033] It can be understood that the temperature of the denitration inlet of the coal-fired unit meeting the preset minimum point condition in the embodiment of the present application can be the minimum point of the denitration inlet temperature of the coal-fired unit.

[0034] Specifically, the embodiment of the present application can calculate the minimum point of the denitration inlet temperature of the coal-fired unit based on the measurement data by using the data processing and analysis module 300, and analyze the flue gas composition after extracting the oxygen and other flue gas components to a mixed header. The flue gas composition at the denitration inlet of the coal-fired unit is analyzed in the mixing box to determine the distribution of nitrogen oxides at the denitration inlet of the coal-fired unit. The comprehensive judgment factor is constructed based on the temperature data and oxygen data, and the blockage of the air preheater, the location of the air leakage and the degree of air leakage are determined according to the comprehensive judgment factor.

[0035] The embodiment of the present application can transmit the collected data to the data processing and analysis module, construct a temperature field distribution model of the denitration inlet and the air preheater outlet, analyze the temperature field distribution characteristics, and obtain the minimum point of the denitration inlet temperature. The flue gas composition data is analyzed, and the distribution of NOx at the denitration inlet is obtained in combination with the temperature field data. The comprehensive judgment factor of the air preheater outlet is constructed to evaluate the health status of the air preheater, so as to realize multi-dimensional and accurate evaluation of the health status of the air preheater. The abnormal conditions such as blockage and air leakage of the air preheater can be found in time, and the operation adjustment and optimization can be performed according to the evaluation results to ensure the safe operation of the air preheater and reduce the maintenance cost.

[0036] It should be noted that the preset minimum point condition can be set by those skilled in the art according to the actual situation, which is not limited here.

[0037] Optionally, in an embodiment of the present application, the data processing and analysis module 300 includes: a temperature field analysis unit configured to construct a temperature field distribution model according to the temperature data, and calculate the temperature of the denitration inlet of the coal-fired unit satisfying the preset minimum point condition according to the temperature field distribution model; a flue gas composition analysis unit configured to process the mixed flue gas composition data and single-point analysis data in the mixing box to obtain target data, and determine the distribution of nitrogen oxides at the denitration inlet of the coal-fired unit based on the target data and the temperature data of the temperature field; and an air preheater health status evaluation unit configured to construct a comprehensive judgment factor according to the temperature satisfying the preset minimum point condition and the distribution of nitrogen oxides, determine the abnormal state of the air preheater according to the comprehensive judgment factor, determine the blockage of the air preheater and the location of the air leakage based on the abnormal state, the actual temperature and the abnormal area of the oxygen distribution, and determine the degree of air leakage according to the corresponding relationship between the outlet temperature of the air preheater and the oxygen.

[0038] It can be understood that the comprehensive judgment factor in the embodiment of the present application is an index constructed based on the temperature and the distribution of nitrogen oxides at the outlet flue cross section of the air preheater.

[0039] In actual implementation, the data processing and analysis server can process the collected data by using MATLAB software. For the denitration inlet temperature data, a temperature field distribution model is constructed by using a bilinear interpolation algorithm, and the lowest point of the denitration inlet temperature is calculated. When the lowest point of the temperature is lower than 300°C (the lower limit of denitration operation), the system sends an alarm signal. At the same time, the mixed flue gas composition data and single-point analysis data in the mixing box are analyzed, and the temperature field data are combined to determine the denitration inlet NOx distribution, which provides a basis for ammonia injection optimization. For the air preheater outlet data, a temperature field and oxygen distribution model is constructed, and the temperature distribution uniformity index (such as temperature standard deviation), oxygen distribution uniformity index (such as oxygen standard deviation), temperature deviation index (deviation from the design temperature), and temperature-oxygen correlation index (such as obtained by correlation analysis) are calculated. The comprehensive judgment factor is obtained by weighted calculation. When the comprehensive judgment factor exceeds the preset threshold value 0.3, it is judged that the air preheater is abnormal, and the air preheater blockage, air leakage position and degree are determined according to the temperature field and oxygen distribution. Specifically, the embodiments of the present application can include: (1) Temperature field analysis: receiving temperature data transmitted by the denitration inlet and air preheater outlet measurement modules, constructing a temperature field distribution model based on Chebyshev grid method measurement data, obtaining the lowest point of the denitration inlet temperature by model calculation, and judging whether it meets the lower limit requirement of denitration operation; analyzing the uniformity and symmetry of the air preheater outlet temperature field distribution, and comparing with the temperature field distribution under standard state to judge whether the air preheater has abnormal conditions such as blockage and air leakage. (2) Flue gas composition analysis: processing the mixed flue gas composition data in the denitration inlet mixing box and single-point analysis data, combining with the temperature field data, analyzing the denitration inlet NOx distribution, and providing data support for denitration system ammonia injection optimization. (3) Air preheater health state assessment: combined with the temperature field and oxygen distribution at the outlet of the air preheater, a comprehensive judgment factor is constructed. The comprehensive judgment factor is based on multiple parameters such as temperature distribution uniformity index, temperature deviation index, oxygen distribution uniformity index, and temperature-oxygen correlation index, and is obtained by weighted calculation through a preset algorithm. According to the comprehensive judgment factor, the health state of the air preheater, such as the degree of blockage, the air leakage condition, and the heat exchange efficiency, is comprehensively evaluated. The calculation method of the comprehensive analysis factor K at the outlet of the air preheater is: K = a * (Tstd / T_avg) + b * (Ostd / Oavg) + c * (ΔTmax / Tavg), wherein Tstd is the standard deviation of the outlet temperature, Tavg is the average outlet temperature, Ostd is the oxygen standard deviation, Oavg is the average oxygen content, ΔTmax is the maximum temperature deviation (compared with the design value), a, b, and c are weight coefficients, which are determined by historical data and expert experience. When the K value exceeds the preset threshold (such as 0.2), it is determined that the state of the air preheater is abnormal, the possible blockage or air leakage position is located according to the specific temperature and oxygen distribution abnormal area, and the suggestion of blowing or maintenance is given.

[0040] In addition, the air preheater outlet temperature and oxygen content can be used to judge the air leakage condition. If the regional temperature continues to decrease and the corresponding regional oxygen content increases, it is warned that the cold end air leakage rate in the region increases; if the exhaust gas temperature in the region continues to increase and the corresponding regional oxygen content increases, it is warned that the hot end air leakage in the region increases; if the exhaust gas temperature in the region increases under the same working condition and the oxygen content does not change significantly, the air preheater resistance change is combined to judge whether the air preheater in the region is blocked.

[0041] The embodiments of the present application can perform air preheater health management: combined with the oxygen content and flue gas temperature distribution at the outlet of the air preheater, a comprehensive judgment factor is proposed, which realizes multi-dimensional and accurate evaluation of the health state of the air preheater, can timely find abnormal conditions such as air preheater blockage and air leakage, and adjust and optimize the operation according to the evaluation results, to ensure the safe operation of the air preheater and reduce the maintenance cost.

[0042] The control execution module 400 is configured to adjust the operating parameters of the denitration system according to the temperature meeting the preset minimum point condition, so as to optimize the operation of the denitration system, and adjust the operating parameters of the air preheater according to the blockage condition, air leakage position and air leakage degree of the air preheater, so as to optimize the operation of the air preheater.

[0043] It can be understood that the denitration system in the embodiments of the present application can be a general term for a series of technologies and equipment for removing nitrogen oxides (NOx) generated in the combustion process of coal-fired units and the like.

[0044] Wherein, the control execution module 400 in the embodiment of the application controls according to the data processing and analysis result. When detecting that the denitration inlet temperature is too low, an instruction is sent to the DCS system (Distributed Control System) to increase the secondary air volume of the burner, to increase the furnace temperature, or to adjust the ammonia injection amount, to optimize the operation of the denitration system. When judging that there is a risk of blockage of the air preheater, the control execution module adjusts the air preheater soot blowing frequency and time; when detecting that the air preheater leakage rate is high, according to the air preheater outlet flue gas temperature and oxygen content data, an instruction is sent to the air preheater sealing sector plate adjustment system to optimize the sector plate position and reduce the leakage rate. By implementing the measurement system and method of the application on the 600 MW coal-fired unit, the denitration efficiency of the denitration system under wide load conditions is increased by 8% - 12%, the ammonia escape amount is reduced by 30% - 40%; the air preheater leakage rate is reduced by 5 - 8 percentage points, the blockage condition is significantly reduced, the safety and economy of the unit operation are significantly improved, and the application provides a basis for sealing adjustment: the air preheater outlet flue gas temperature and oxygen content data are used to guide the adjustment of the air preheater sealing sector plate, which provides effective data support for the sector plate to control the leakage rate, can optimize the sealing performance of the air preheater, reduce the leakage rate, and improve the operation efficiency of the unit.

[0045] Specifically, the embodiment of the application can include: (1) Denitration system control: according to the denitration inlet temperature field data provided by the data processing and analysis module, when detecting that the minimum point of the denitration inlet temperature is close to or lower than the lower limit of the denitration operation, the control execution module sends an instruction to adjust the operation of the wide load denitration system, such as adjusting the ammonia injection amount, optimizing the combustion condition, etc., to ensure that there is no low point in the denitration inlet flue gas temperature, to improve the denitration efficiency, and to reduce ammonia escape. (2) Air preheater optimization adjustment: according to the air preheater outlet temperature field, oxygen content distribution and comprehensive judgment factor, the control execution module sends an instruction to adjust the operating parameters of the air preheater, such as adjusting the comprehensive cold end temperature to prevent the air preheater from being blocked; at the same time, combined with the air preheater outlet flue gas temperature and oxygen content data, the air preheater sealing sector plate adjustment is provided with a basis to optimize the sector plate position and reduce the air preheater leakage rate.

[0046] The embodiment of the application can control and adjust the denitration system and the air preheater according to the results of the data processing and analysis module. For the denitration system, the denitration inlet flue gas temperature meets the operation requirements, and the ammonia injection amount is optimized; for the air preheater, the operating parameters are adjusted, the sector plate position is adjusted, and the safe and efficient operation of the air preheater is ensured. The embodiment of the application can optimize the denitration control: by monitoring the denitration inlet flue gas temperature field in real time, the wide load denitration system can be more comprehensively controlled, the denitration system operating parameters can be adjusted in time according to the temperature field, the denitration inlet flue gas temperature can be ensured to meet the requirements, and the adaptability and stability of the denitration system can be improved.

[0047] Specifically, the working principle of the parameter control system of the coal-fired unit denitration inlet and the air preheater outlet in the embodiments of the present application can be described in combination with Figure 2 The working principle of the parameter control system of the coal-fired unit denitration inlet and the air preheater outlet in the embodiments of the present application is described in detail.

[0048] As shown in Figure 2 The arrangement position schematic diagram of the measuring support in the flue in the embodiments of the present application includes: 1-Selective Catalytic Reduction (SCR), 2-air preheater, 3-measuring support, 4-temperature bus, 5-temperature collection box, 6-mixing header I, 7-mixing header II, 8-flue gas analyzer I, 9-flue gas analyzer II, 10-shutoff valve, 11-flue gas sampling port, 12-temperature thermocouple probe, and 13-flow regulating valve. The arrangement schematic diagram of the flue gas parameter analysis system in A-A / B-B cross section is shown in Figure 3 The internal structure schematic diagram of the measuring support is shown in Figure 4 .

[0049] The parameter control system of the coal-fired unit denitration inlet and the air preheater outlet according to the embodiments of the present application can realize high-precision measurement of the temperature field of the denitration inlet and the air preheater outlet and the flue gas composition through the innovative measurement system and method, provide reliable data support for wide-load denitration control and air preheater health management, and guarantee the safe, efficient, and environmentally friendly operation of the coal-fired unit under the new power system. Thus, the problems of insufficient temperature measurement points of the coal-fired unit denitration inlet and the air preheater outlet, incomplete temperature field measurement, single flue gas composition measurement, inability to effectively realize wide-load denitration precise control, and difficulty in accurately evaluating the health status of the air preheater and performing optimization adjustment in the related art are solved.

[0050] Next, the parameter control method of the coal-fired unit denitration inlet and the air preheater outlet according to the embodiments of the present application is described with reference to the accompanying drawings.

[0051] Figure 5 The flowchart of the parameter control method of the coal-fired unit denitration inlet and the air preheater outlet according to the embodiments of the present application is shown in

[0052] As shown in Figure 5 The parameter control method of the coal-fired unit denitration inlet and the air preheater outlet includes the following steps. In step S501, after arranging multiple measuring supports at the flue cross section of the coal-fired unit denitration inlet, uniform flue gas sampling is performed on the flue gas sampling ports prearranged on the multiple measuring supports, and temperature field measurement coupling is performed on the temperature thermocouple probes prearranged on the multiple measuring supports to generate the measurement data of the coal-fired unit denitration inlet.

[0053] In step S502, after the plurality of measuring supports are arranged at the outlet flue cross section of the air preheater, the temperature field at the outlet flue cross section is measured by using the temperature thermocouple probes previously arranged on the plurality of measuring supports, and the flue gas is extracted by using the flue gas sampling ports previously arranged on the plurality of measuring supports, the oxygen field distribution at the outlet flue cross section is measured by the mixing header, and the temperature field data and the oxygen field data at the outlet flue cross section are obtained according to the temperature field and the oxygen field distribution.

[0054] In step S503, the temperature satisfying the preset minimum point condition at the denitration inlet of the coal-fired unit is calculated based on the measurement data, the flue gas composition at the denitration inlet of the coal-fired unit is analyzed in the mixing box to determine the distribution of the nitrogen oxides at the denitration inlet of the coal-fired unit, the comprehensive judgment factor is constructed based on the temperature field data and the oxygen field data obtained by the air preheater outlet measurement module, and the blockage condition, the air leakage position and the air leakage degree of the air preheater are determined according to the comprehensive judgment factor.

[0055] In step S504, the operation parameters of the denitration system are adjusted according to the temperature satisfying the preset minimum point condition to optimize the operation of the denitration system, and the operation parameters of the air preheater are adjusted according to the blockage condition, the air leakage position and the air leakage degree of the air preheater to optimize the operation of the air preheater.

[0056] Optionally, in an embodiment of the present application, the flue gas is uniformly sampled from the flue gas sampling ports previously arranged on the plurality of measuring supports, and the temperature measurement is coupled to at least one temperature thermocouple probe previously arranged on the plurality of measuring supports to generate the measurement data of the denitration inlet of the coal-fired unit, including: obtaining the flue gas temperature and the flue gas composition information at the flue cross section of the denitration inlet of the coal-fired unit; after the mixing box is arranged, the flue gas of each branch pipe is mixed in the mixing box after multi-point sampling to analyze the flue gas composition, determine the flue gas composition data of the denitration inlet of the coal-fired unit, and generate the measurement data of the denitration inlet according to the flue gas composition data.

[0057] Optionally, in an embodiment of the present application, the flue gas is uniformly sampled from the flue gas sampling ports previously arranged on the plurality of measuring supports, and the temperature measurement is coupled to at least one temperature thermocouple probe previously arranged on the plurality of measuring supports to generate the measurement data of the denitration inlet of the coal-fired unit, including: obtaining the flue gas temperature and the flue gas composition information at the flue cross section of the denitration inlet of the coal-fired unit; after the mixing box is arranged, the flue gas of each branch pipe is mixed in the mixing box after multi-point sampling to analyze the flue gas composition, determine the flue gas composition data of the denitration inlet of the coal-fired unit, and generate the measurement data of the denitration inlet according to the flue gas composition data.

[0058] Optionally, in an embodiment of the present application, the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition is calculated based on the measurement data, and the flue gas composition at the denitration inlet of the coal-fired generating unit is analyzed in the mixing box to determine the distribution of nitrogen oxides at the denitration inlet of the coal-fired generating unit, a comprehensive judgment factor is constructed based on the temperature field data and the oxygen amount field data obtained by the air preheater outlet measurement module, and the blockage condition, the air leakage position and the air leakage degree of the air preheater are determined according to the comprehensive judgment factor, including: a temperature field distribution model is constructed according to the temperature field data, and the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition is calculated according to the temperature field distribution model; the mixed flue gas composition data and the single-point analysis data in the mixing box are processed to obtain target data, and the distribution of nitrogen oxides at the denitration inlet of the coal-fired generating unit is determined based on the target data and the temperature field data; a comprehensive judgment factor is constructed according to the temperature at which the denitration inlet of the coal-fired generating unit meets the preset minimum point condition and the distribution of nitrogen oxides, and the abnormal state of the air preheater is determined according to the comprehensive judgment factor, the blockage condition and the air leakage position of the air preheater are determined based on the abnormal state, the actual temperature and the abnormal area of the oxygen amount distribution, and the air leakage degree is determined according to the corresponding relationship between the outlet temperature and the oxygen amount of the air preheater.

[0059] It should be noted that the foregoing explanation and description of the embodiment of the coal-fired generating unit denitration inlet and air preheater outlet parameter control system also apply to the coal-fired generating unit denitration inlet and air preheater outlet parameter control method of this embodiment, which will not be described here.

[0060] The coal-fired generating unit denitration inlet and air preheater outlet parameter control method provided by the embodiment of the present application can achieve high-precision measurement of the temperature field and flue gas composition at the denitration inlet and the air preheater outlet through innovative measurement systems and methods, provide reliable data support for wide-load denitration control and air preheater health management, and ensure the safe, efficient and environmentally friendly operation of the coal-fired generating unit under the new power system. Thus, the problems of insufficient temperature measurement points, incomplete temperature field measurement, single flue gas composition measurement, inability to effectively achieve precise control of wide-load denitration, and difficulty in accurately evaluating the health status of the air preheater and optimizing the adjustment in the related art are solved.

[0061] Figure 6 A structural schematic diagram of an electronic device is provided for the embodiment of the present application. The electronic device can include: a memory 601, a processor 602, and a computer program stored on the memory 601 and executable on the processor 602.

[0062] The processor 602 implements the coal-fired generating unit denitration inlet and air preheater outlet parameter control method provided in the above embodiments when executing the program.

[0063] Further, the electronic device further includes: The communication interface 603 is configured to communicate between the memory 601 and the processor 602.

[0064] The memory 601 is configured to store a computer program executable on the processor 602.

[0065] The memory 601 can include a high-speed RAM memory, and can further include a non-volatile memory, for example, at least one disk memory.

[0066] If the memory 601, the processor 602 and the communication interface 603 are independently implemented, the communication interface 603, the memory 601 and the processor 602 can be connected with each other through a bus and complete communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 6 Only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0067] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can complete communication between each other through an internal interface.

[0068] The processor 602 can be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0069] The embodiment also provides a computer readable storage medium, which stores a computer program, and the program is executed by the processor to implement the above-mentioned coal-fired unit denitration inlet and air preheater outlet parameter control method.

[0070] In the description of the application, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, the usage of "N" means at least two, for example, two, three or the like, unless explicitly stated otherwise.

[0071] Furthermore, the terms "first", "second", or the like, are used only to describe the different features and do not imply or suggest relative importance of, or a number of, the indicated technical features. Thus, the features defined with "first", "second" can include at least one of the features explicitly or implicitly. In the description of the application, "N" means at least two, for example, two, three, etc., unless explicitly specified otherwise.

[0072] Any process or method descriptions or descriptions of the flow diagrams in the present application can be understood as representing code modules, segments, or portions of code which include one or more executable instructions for performing specific logic functions or steps in the process, and that the various systems and methods described herein can include an order of steps which can be executed in any suitable order, including substantially concurrently, in reverse order, or in other suitable order, as would be understood by one of ordinary skill in the art.

[0073] The logic and / or steps represented in the flowcharts and / or described herein, for example, can be considered as a sequence of executable instructions stored in a computer readable medium, which can be executed by an instruction execution system, apparatus or device, such as a computer-based system, processor- based system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination thereof. For the purposes of this specification, a "computer readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can be a computer readable storage medium or a computer readable signal medium. The computer readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a propagation medium. The computer readable signal medium can include, but is not limited to, a computer readable medium that facilitates transfer of the program from one place to another. A specific example of a computer readable medium is a non-transitory computer-readable storage medium. A specific example of a computer readable signal medium is a source or destination of the computer readable medium. Another specific example of a computer readable signal medium is a computer readable signal travelling through space. Thus, a computer readable medium can take many forms of hardware to carry out the program for use by or in connection with the instruction execution system, apparatus, or device.

[0074] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As such, if implemented in hardware, and in another embodiment, any of the following technologies, known in the art, or their combinations can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0075] Those of skill in the art would understand that the steps carried out by the above-mentioned embodiments of the method can be implemented by programs instructing the relevant hardware, and the programs can be stored in a computer readable storage medium. When the programs are executed, they include one or a combination of the steps of the method embodiments.

[0076] In addition, each of the functional units in the various embodiments of the present application can be integrated in one processing module, or each of the units can be physically present separately, or two or more units can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented 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.

[0077] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A control system for denitrification inlet and air preheater outlet parameters of a coal-fired power unit, characterized in that, include: The denitrification inlet measurement module is used to uniformly sample flue gas at the flue gas sampling ports pre-set on the multiple measurement supports after arranging multiple measurement supports at the flue gas cross-section of the denitrification inlet of the coal-fired unit, and to perform temperature field measurement coupling with the temperature thermocouple probes pre-set on the multiple measurement supports to generate measurement data of the denitrification inlet of the coal-fired unit. An air preheater outlet measurement module is used to measure the temperature field at the outlet flue section of the air preheater by arranging the multiple measurement brackets on the multiple measurement brackets and using the temperature thermocouple probes pre-set on the multiple measurement brackets to measure the flue gas, and to extract flue gas by using the flue gas sampling ports pre-set on the multiple measurement brackets, and to measure the oxygen field distribution at the outlet flue section through a mixing header, so as to obtain the temperature field data and oxygen field data at the outlet flue section based on the temperature field and the oxygen field distribution; The data processing and analysis module is used to calculate the temperature at which the denitrification inlet of the coal-fired power unit meets the preset minimum point condition based on the measurement data, and to analyze the flue gas composition at the denitrification inlet of the coal-fired power unit in the mixing box to determine the distribution of nitrogen oxides at the denitrification inlet of the coal-fired power unit. Based on the temperature field data and oxygen field data obtained by the air preheater outlet measurement module, a comprehensive judgment factor is constructed, and the blockage status, air leakage location and air leakage degree of the air preheater are determined according to the comprehensive judgment factor. The control execution module is used to adjust the operating parameters of the denitrification system according to the temperature that meets the preset minimum point condition in order to optimize the operation of the denitrification system, and to adjust the operating parameters of the air preheater according to the blockage, leakage location and degree of the air preheater in order to optimize the operation of the air preheater.

2. The control system for denitrification inlet and air preheater outlet parameters of a coal-fired power unit according to claim 1, characterized in that, The denitrification inlet measurement module includes: Temperature field and flue gas composition measurement unit, used to acquire flue gas temperature and flue gas composition information at the flue gas cross section of the denitrification inlet of the coal-fired unit; The flue gas analysis unit is used to mix the flue gas from each branch pipe after multiple sampling points are set in the mixing box, so as to perform flue gas composition analysis on the flue gas temperature and flue gas composition information, determine the flue gas composition data of the denitrification inlet of the coal-fired unit, and generate the measurement data of the denitrification inlet based on the flue gas composition data.

3. The control system for denitrification inlet and air preheater outlet parameters of a coal-fired power unit according to claim 2, characterized in that, The denitrification inlet measurement module also includes: The sampling pipeline includes a flow regulating valve and a branch pipe. The flow regulating valve is used to adjust the flue gas flow at the denitrification inlet of the coal-fired unit or close the branch pipe according to the target measurement requirements. The branch pipe is configured in a dual-path way, so that if the first branch meets the preset fault conditions, the second branch can perform single-point flue gas composition analysis according to actual needs to obtain the oxygen field distribution.

4. The control system for denitrification inlet and air preheater outlet parameters of a coal-fired power unit according to claim 1, characterized in that, The data processing and analysis module includes: The temperature field analysis unit is used to construct a temperature field distribution model based on the temperature data, and to calculate the temperature at the denitrification inlet of the coal-fired unit that meets the preset minimum point condition based on the temperature field distribution model. The flue gas composition analysis unit is used to process the flue gas composition data and single-point analysis data after mixing in the mixing box to obtain target data, and based on the target data and the temperature data of the temperature field, to determine the distribution of nitrogen oxides at the denitrification inlet of the coal-fired unit. An air preheater health status assessment unit is used to construct a comprehensive judgment factor based on the temperature that meets the preset minimum point condition and the distribution of nitrogen oxides, determine the abnormal state of the air preheater based on the comprehensive judgment factor, determine the blockage and leakage location of the air preheater based on the abnormal state, actual temperature and abnormal oxygen distribution area, and determine the degree of leakage based on the correspondence between the outlet temperature and oxygen content of the air preheater.

5. A method for controlling the parameters of the denitrification inlet and air preheater outlet of a coal-fired power unit, characterized in that, Includes the following steps: After arranging multiple measuring supports at the flue section of the denitrification inlet of the coal-fired power unit, flue gas is uniformly sampled at the flue gas sampling ports pre-set on the multiple measuring supports, and temperature field measurement coupling is performed on the temperature thermocouple probes pre-set on the multiple measuring supports to generate measurement data of the denitrification inlet of the coal-fired power unit. After arranging the multiple measuring brackets at the outlet flue section of the air preheater, the temperature field at the outlet flue section is measured using the temperature thermocouple probes pre-set on the multiple measuring brackets, and flue gas is extracted using the flue gas sampling ports pre-set on the multiple measuring brackets. The oxygen field distribution at the outlet flue section is measured through the mixing header, so as to obtain the temperature field data and oxygen field data at the outlet flue section based on the temperature field and the oxygen field distribution. Based on the measurement data, the temperature at which the denitrification inlet of the coal-fired power unit meets the preset minimum point condition is calculated. The flue gas composition at the denitrification inlet of the coal-fired power unit is analyzed in the mixing box to determine the distribution of nitrogen oxides at the denitrification inlet of the coal-fired power unit. Based on the temperature field data and oxygen field data obtained by the air preheater outlet measurement module, a comprehensive judgment factor is constructed. Based on the comprehensive judgment factor, the blockage status, air leakage location and air leakage degree of the air preheater are determined. The operating parameters of the denitrification system are adjusted according to the temperature that meets the preset minimum point condition to optimize the operation of the denitrification system. The operating parameters of the air preheater are also adjusted according to the blockage, leakage location and degree of the air preheater to optimize the operation of the air preheater.

6. The method for controlling the parameters of the denitrification inlet and air preheater outlet of a coal-fired power unit according to claim 5, characterized in that, The process of uniformly sampling flue gas through pre-installed flue gas sampling ports on the multiple measuring supports, and coupling temperature measurement data with at least one pre-installed temperature thermocouple probe on the multiple measuring supports to generate measurement data for the denitrification inlet of the coal-fired unit, includes: Obtain flue gas temperature and composition information at the flue gas cross-section of the denitrification inlet of the coal-fired unit; After setting up the mixing box, the flue gas from each branch pipe is sampled at multiple points and mixed in the mixing box to analyze the flue gas temperature and composition information, determine the flue gas composition data at the denitrification inlet of the coal-fired unit, and generate the measurement data of the denitrification inlet based on the flue gas composition data.

7. The method for controlling the parameters of the denitrification inlet and air preheater outlet of a coal-fired power unit according to claim 6, characterized in that, The step of uniformly sampling flue gas through the pre-set flue gas sampling ports on the plurality of measuring supports further includes: When the first branch meets the preset fault conditions, the second branch performs single-point flue gas composition analysis according to actual needs to obtain the oxygen field distribution.

8. The method for controlling the parameters of the denitrification inlet and air preheater outlet of a coal-fired power unit according to claim 6, characterized in that, The process involves calculating the temperature at the denitrification inlet of the coal-fired power unit that meets the preset minimum point condition based on the measured data, analyzing the flue gas composition at the denitrification inlet of the coal-fired power unit in the mixing chamber to determine the distribution of nitrogen oxides at the denitrification inlet of the coal-fired power unit, constructing a comprehensive judgment factor based on the temperature field data and oxygen field data obtained from the air preheater outlet measurement module, and determining the blockage status, leakage location, and leakage degree of the air preheater based on the comprehensive judgment factor, including: A temperature field distribution model is constructed based on the temperature field data, and the temperature at the denitrification inlet of the coal-fired unit that meets the preset minimum point condition is calculated based on the temperature field distribution model. The flue gas composition data and single-point analysis data after mixing in the mixing box are processed to obtain target data. Based on the target data and the temperature field data, the distribution of nitrogen oxides at the denitrification inlet of the coal-fired unit is determined. The comprehensive judgment factor is constructed based on the temperature that meets the preset minimum point condition and the distribution of nitrogen oxides. The abnormal state of the air preheater is determined based on the comprehensive judgment factor. Based on the abnormal state, the actual temperature and the abnormal oxygen distribution area, the blockage and leakage location of the air preheater are determined. The degree of leakage is determined based on the correspondence between the outlet temperature and oxygen content of the air preheater.

9. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for controlling the denitrification inlet and air preheater outlet parameters of a coal-fired unit as described in any one of claims 7-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for controlling the denitrification inlet and air preheater outlet parameters of a coal-fired unit as described in any one of claims 7-8.

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