Analysis methods, systems, equipment and media for pollutant emission characteristics of thermal power units

Abstract

The invention discloses a method, system, equipment and medium for analyzing the pollutant emission characteristics of a thermal power unit. The method comprises: obtaining historical pollutant emission data of the thermal power unit under different load conditions, screening, and obtaining the screened historical pollutant emission data; fitting the screened historical pollutant emission data using a quadratic function to obtain a pollutant emission characteristic curve of the thermal power unit; obtaining specific differences in pollutant emissions of different thermal power units according to the pollutant emission characteristic curve of the thermal power unit, that is, obtaining the analysis results of the pollutant emission characteristics of the thermal power unit; the invention adopts a quadratic function for curve fitting, which is more in line with reality, has high accuracy in calculation results, and is simple in calculation process, meeting engineering requirements; using the pollutant emission characteristic curve, the pollutant emission values ​​under different load conditions can be intuitively obtained, and the pollutant emission characteristic curves of different thermal power units can be compared to obtain the specific differences in emissions of each unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal power generation, and in particular relates to a method, system, equipment and medium for analyzing pollutant emission characteristics of a thermal power unit. Background Art

[0002] Saving energy, reducing emissions and curbing climate warming have become a common challenge and important issue facing the world. my country attaches great importance to energy conservation and emission reduction in the power industry, and has proposed to implement energy-saving power generation and dispatching in the power sector, improve the energy efficiency of the power industry, reduce environmental pollution, and promote the adjustment of energy and power structure.

[0003] At present, power grid companies that have carried out energy-saving power generation scheduling generally have problems such as incomplete research on unit energy consumption and pollutant emission characteristics, inaccurate emission curve production, etc., which have created certain obstacles to the real application and promotion of energy-saving power generation scheduling. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a method, system, equipment and medium for analyzing the pollutant emission characteristics of a thermal power unit to solve the technical problems in the prior art, such as the lack of thorough research on the energy consumption and pollutant emission characteristics of the unit and the inaccurate generation of pollutant emission curves.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a method for analyzing pollutant emission characteristics of a thermal power unit, comprising the following steps:

[0007] Obtain historical data on pollutant emissions from thermal power units under different load conditions;

[0008] According to the stability characteristics of thermal power units, the historical data of pollutant emissions under different load conditions of thermal power units are screened to obtain screened historical data of pollutant emissions;

[0009] The pollutant emission characteristic curve of the thermal power unit is obtained by fitting the filtered historical data of pollutant emission using quadratic function;

[0010] According to the pollutant emission characteristic curve of the thermal power unit, the specific differences of pollutant emissions of different thermal power units are obtained, that is, the analysis results of the pollutant emission characteristics of the thermal power unit are obtained.

[0011] Furthermore, the historical data of pollutant emissions under different load conditions of the thermal power unit are historical data of pollutant emissions at a plurality of load points of the thermal power unit; wherein the plurality of load points are evenly distributed between the minimum load and the maximum load of the thermal power unit.

[0012] Furthermore, the historical data of pollutant emissions under different load conditions of thermal power units include SO2 emissions, NO X One of emissions and smoke emissions.

[0013] Furthermore, according to the stability characteristics of the thermal power units, the historical data of pollutant emissions under different load conditions of the thermal power units are screened to obtain the screened historical data of pollutant emissions, which is specifically as follows:

[0014] Determine the stability characteristics of thermal power units;

[0015] Calculate the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of thermal power units;

[0016] If the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of the thermal power unit is greater than the preset change rate value, the historical data of pollutant emissions under the corresponding load conditions of the thermal power unit are discarded; otherwise, they are retained to obtain the screened historical data of pollutant emissions.

[0017] Furthermore, the stability characteristics of the thermal power unit include the unit's power generation capacity, main feed water flow, main steam pressure, main steam temperature and reheat steam temperature.

[0018] Furthermore, the process of fitting the filtered pollutant emission historical data using a quadratic function to obtain the pollutant emission characteristic curve of the thermal power unit is as follows:

[0019] Based on the least squares method, a quadratic function between the pollution emission of thermal power units and the unit load is established;

[0020] The quadratic function of the pollutant emissions of the thermal power units and the unit load is used to fit the screened historical data of pollutant emissions and obtain the pollutant emission characteristic curve of the thermal power units.

[0021] Furthermore, the quadratic function expression of the pollutant emissions of thermal power units and unit load is:

[0022] M=f(p)=a1p 2 +a2p+a3

[0023] Among them, M is the pollutant emission of the thermal power unit; a1 is the quadratic term coefficient of the quadratic function; a2 is the linear term coefficient of the quadratic function; a3 is the constant term coefficient of the quadratic function; and p is the load of the thermal power unit.

[0024] The present invention also provides a system for analyzing pollutant emission characteristics of a thermal power unit, comprising:

[0025] A historical data acquisition module is used to obtain historical data of pollutant emissions under different load conditions of thermal power units;

[0026] A screening module is used to screen the historical data of pollutant emissions under different load conditions of the thermal power units according to the stability characteristics of the thermal power units, and obtain the screened historical data of pollutant emissions;

[0027] A fitting calculation module is used to fit the filtered pollutant emission historical data using a quadratic function to obtain a pollutant emission characteristic curve of the thermal power unit;

[0028] The curve analysis module is used to obtain the specific differences in pollutant emissions of different thermal power units based on the pollutant emission characteristic curve of the thermal power unit, that is, to obtain the analysis results of the pollutant emission characteristics of the thermal power unit.

[0029] The present invention also provides a thermal power unit pollutant emission characteristic analysis device, comprising:

[0030] Memory for storing computer programs;

[0031] A processor is used to implement the steps of the method for analyzing pollutant emission characteristics of thermal power units when executing the computer program.

[0032] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for analyzing pollutant emission characteristics of a thermal power unit are implemented.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a method for analyzing the pollutant emission characteristics of a thermal power unit. The method screens historical pollutant emission data under different load conditions and uses a quadratic function to fit and calculate to obtain a pollutant emission characteristic curve. Since the actual marginal pollutant curve is a concave U-shaped function, the quadratic function is used to fit the pollutant emission characteristic curve, which is more in line with reality, has high accuracy in the calculation result, and is simple in the calculation process, meeting engineering requirements. At the same time, the pollutant emission characteristic curve can be used to intuitively obtain the pollutant emission values ​​under different load conditions, and the pollutant emission characteristic curves of different thermal power units can be compared to obtain the emission-specific differences of each unit.

[0035] Furthermore, the SO2 and NO X And the smoke inlet and outlet emission curves. Through real-time monitoring and analysis of each curve, the optimal operating environment of pollutants under different operating conditions can be obtained, which not only lays a solid data foundation for the good operation of the unit, but also provides technical support for the economic allocation and optimal scheduling of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of the method for analyzing the pollutant emission characteristics of a thermal power unit according to the present invention;

[0037] Figure 2 It is a graph of SO2 inlet emission and load in the embodiment;

[0038] Figure 3 It is a graph of SO2 outlet emission and load in the embodiment;

[0039] Figure 4 NO in the embodiment X Inlet discharge and load curves;

[0040] Figure 5 NO in the embodiment X Export discharge and load curves;

[0041] Figure 6 is a graph showing smoke inlet emission and load in the embodiment;

[0042] Figure 7 It is a smoke outlet emission and load curve diagram in the embodiment. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] As attached Figure 1 As shown, the present invention provides a method for analyzing pollutant emission characteristics of a thermal power unit, comprising the following steps:

[0045] Step 1: Obtain historical data of pollutant emissions under different load conditions of thermal power units. The historical data of pollutant emissions under different load conditions of thermal power units are historical data of pollutant emissions at several load points of the thermal power units; the several load points are evenly distributed between the minimum load and the maximum load of the thermal power units; the historical data of pollutant emissions under different load conditions of the thermal power units include SO2 emissions, NO X One of emissions or smoke emissions.

[0046] Step 2: According to the stability characteristics of the thermal power units, the historical data of pollutant emissions under different load conditions of the thermal power units are screened to obtain screened historical data of pollutant emissions.

[0047] The screening process is as follows:

[0048] Determine the stability characteristics of thermal power units; the stability characteristics of thermal power units include unit power generation, main feed water flow, main steam pressure, main steam temperature and reheat steam temperature

[0049] Calculate the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of thermal power units;

[0050] If the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of the thermal power unit is greater than the preset change rate value, the historical data of pollutant emissions under the corresponding load conditions of the thermal power unit are discarded; otherwise, they are retained to obtain the screened historical data of pollutant emissions.

[0051] Step 3: Use a quadratic function to fit the screened historical pollutant emission data to obtain the pollutant emission characteristic curve of the thermal power unit.

[0052] The specific process is as follows:

[0053] Based on the least squares method, a quadratic function of the pollution emissions of thermal power units and the unit load is established; among them, the expression of the quadratic function of the pollutant emissions of thermal power units and the unit load is:

[0054] M=f(p)=a1p 2 +a2p+a3

[0055] Among them, M is the pollutant emission of the thermal power unit; a1 is the quadratic term coefficient of the quadratic function; a2 is the linear term coefficient of the quadratic function; a3 is the constant term coefficient of the quadratic function; and p is the load of the thermal power unit.

[0056] The quadratic function of the pollutant emissions of the thermal power units and the unit load is used to fit the screened historical data of pollutant emissions and obtain the pollutant emission characteristic curve of the thermal power units.

[0057] In the present invention, the principle of fitting and calculating the pollutant emission characteristic curve of the thermal power unit is as follows:

[0058] As the main method for calculating pollutant emission curves using quadratic functions, the least squares method can be used to process a set of data to seek the dependency relationship between variables. The above functional relationship is called an empirical formula.

[0059] Assume that the experiment measures n data between variables (x1, y1), (x2, y2), ..., (x n ,y n ), then on the XOY plane, we can get n points p(x i ,y i), i = 1, K, n, this kind of graph is called a "scatter plot". If it can be roughly seen from the graph that these points are roughly scattered near a quadratic curve, then it is believed that the function between the variable x and the variable y is approximately a quadratic function.

[0060] Constructing the quadratic function y=ax 2 +bx+c, where a, b, c are unknown constants. Since n points are generally not on the same quadratic curve, there is a certain deviation, which is denoted by ε i =y i -(ax i 2 +bx i +c).

[0061] If the deviation is required to be as small as possible, but due to ε i Can be positive or negative, so it cannot be considered as a total deviation When y=ax 2 +bx+c reflects the relationship between variables very well, because the absolute value of each deviation may be large at this time.

[0062] In order to improve the above defects, the total absolute deviation is used Instead of total deviation However, since the absolute value is not easy to perform analytical calculations, the total square deviation is used because the minimum sum of squares of the deviations can ensure that each deviation is not large. to measure the total deviation; thus, the quadratic function fitting problem is reduced to determining y = ax 2 +bx+c in which the constants a, b and c make The method of determining the coefficients a, b and c using the above method is called the least squares method.

[0063] According to the extreme value principle:

[0064]

[0065] Right now,

[0066]

[0067]

[0068] Solving this system of linear equations yields the constants a, b, and c.

[0069] Step 4: According to the pollutant emission characteristic curve of the thermal power unit, the specific differences in pollutant emissions of different thermal power units are obtained, that is, the analysis results of the pollutant emission characteristics of the thermal power units are obtained; in the present invention, according to the pollutant emission characteristic curve of the thermal power unit, the pollutant emission values ​​under different load conditions can be intuitively obtained, and at the same time, the pollutant emission characteristic curves of different thermal power units can be compared, thereby obtaining the specific differences of each thermal power unit.

[0070] The present invention also provides a pollutant emission characteristic analysis system for thermal power units, comprising a historical data acquisition module, a screening module, a fitting calculation module and a curve analysis module: the historical data acquisition module is used to acquire the pollutant emission historical data of the thermal power units under different load conditions; the screening module is used to screen the pollutant emission historical data of the thermal power units under different load conditions according to the stability characteristics of the thermal power units, and obtain the screened pollutant emission historical data; the fitting calculation module is used to fit the screened pollutant emission historical data using a quadratic function to obtain the pollutant emission characteristic curve of the thermal power units; the curve analysis module is used to obtain the specific differences in pollutant emissions of different thermal power units according to the pollutant emission characteristic curve of the thermal power units, that is, to obtain the pollutant emission characteristic analysis results of the thermal power units.

[0071] The present invention also provides a device for analyzing the pollutant emission characteristics of a thermal power unit, comprising: a memory for storing a computer program; and a processor for implementing the steps of the method for analyzing the pollutant emission characteristics of a thermal power unit when executing the computer program.

[0072] When the processor executes the computer program, the steps of the above-mentioned method for analyzing the pollutant emission characteristics of the thermal power unit are implemented, for example: obtaining historical data of pollutant emissions under different load conditions of the thermal power unit; screening the historical data of pollutant emissions under different load conditions of the thermal power unit according to the stability characteristics of the thermal power unit to obtain the screened historical data of pollutant emissions; fitting the screened historical data of pollutant emissions using a quadratic function to obtain a pollutant emission characteristic curve of the thermal power unit; according to the pollutant emission characteristic curve of the thermal power unit, obtaining the specific differences in pollutant emissions of different thermal power units, that is, obtaining the pollutant emission characteristic analysis results of the thermal power unit.

[0073] Alternatively, when the processor executes the computer program, it implements the functions of each module in the above-mentioned system, for example: a historical data acquisition module, which is used to obtain the historical data of pollutant emissions under different load conditions of the thermal power unit; a screening module, which is used to screen the historical data of pollutant emissions under different load conditions of the thermal power unit according to the stability characteristics of the thermal power unit, and obtain the screened historical data of pollutant emissions; a fitting calculation module, which is used to fit the screened historical data of pollutant emissions using a quadratic function to obtain a pollutant emission characteristic curve of the thermal power unit; a curve analysis module, which is used to obtain the specific differences in pollutant emissions of different thermal power units according to the pollutant emission characteristic curve of the thermal power unit, that is, to obtain the pollutant emission characteristic analysis results of the thermal power unit.

[0074] Exemplarily, the computer program can be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the pollutant emission characteristic analysis device of the thermal power unit. For example, the computer program can be divided into a historical data acquisition module, a screening module, a fitting calculation module and a curve analysis module: the specific functions of each module are as follows: a historical data acquisition module, which is used to obtain the historical data of pollutant emissions under different load conditions of the thermal power unit; a screening module, which is used to screen the historical data of pollutant emissions under different load conditions of the thermal power unit according to the stability characteristics of the thermal power unit, and obtain the filtered historical data of pollutant emissions; a fitting calculation module, which is used to fit the filtered historical data of pollutant emissions using a quadratic function to obtain the pollutant emission characteristic curve of the thermal power unit; a curve analysis module, which is used to obtain the specific differences of pollutant emissions of different thermal power units according to the pollutant emission characteristic curve of the thermal power unit, that is, to obtain the analysis results of the pollutant emission characteristics of the thermal power unit.

[0075] The thermal power unit pollutant emission characteristic analysis device may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The thermal power unit pollutant emission characteristic analysis device may include, but is not limited to, a processor and a memory. Those skilled in the art may understand that the above is only an example of a thermal power unit pollutant emission characteristic analysis device, and does not constitute a limitation on the thermal power unit pollutant emission characteristic analysis device, and may include more components, or a combination of certain components, or different components. For example, the thermal power unit pollutant emission characteristic analysis device may also include input and output devices, network access devices, buses, etc.

[0076] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The processor is the control center of the pollutant emission characteristic analysis device of the thermal power unit, and uses various interfaces and lines to connect various parts of the entire pollutant emission characteristic analysis device of the thermal power unit.

[0077] The memory can be used to store the computer program and / or module, and the processor implements various functions of the thermal power unit pollutant emission characteristic analysis device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0078] The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (SmartMediaCard, SMC), a secure digital (SecureDigital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0079] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for analyzing pollutant emission characteristics of a thermal power unit are implemented.

[0080] If the module / unit integrated in the pollutant emission characteristic analysis device for thermal power units is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0081] Based on such understanding, the present invention implements all or part of the processes in the above method, and can also be completed by instructing related hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the above-mentioned method for analyzing the pollutant emission characteristics of thermal power units can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or preset intermediate form, etc.

[0082] The computer-readable storage medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0083] It should be noted that the content contained in the computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media do not include electrical carrier signals and telecommunication signals.

[0084] Example

[0085] Taking a 350MW subcritical unit as an example, this embodiment provides a method for analyzing pollutant emission characteristics of a thermal power unit, which specifically includes the following steps:

[0086] Step 1: Historical data extraction

[0087] The corresponding SO2, NO X and smoke emissions; wherein different load points are evenly distributed between the minimum load and the maximum load of the corresponding thermal power unit; in this embodiment, the historical data of pollutant emissions at different load points are shown in Table 1 below.

[0088] Table 1 Historical data of pollutant emissions from thermal power units under different load conditions

[0089] Power(MW) SO2 emission (g / h) NOX emissions (g / h) Dust emission (g / h) <![CDATA[P1]]> <![CDATA[F1]]> <![CDATA[G1]]> <![CDATA[H 1 <!-- 6 -->]]> <![CDATA[P2]]> <![CDATA[F2]]> <![CDATA[G2]]> <![CDATA[H 2]]> <![CDATA[P3]]> <![CDATA[F3]]> <![CDATA[G3]]> <![CDATA[H 3]]> … … … … <![CDATA[P n ]]> <![CDATA[F n ]]> <![CDATA[G n ]]> <![CDATA[H n ]]>

[0090] Step 2: Unit stability assessment and data screening

[0091] According to the stability characteristics of the thermal power units, the historical data of pollutant emissions under different load conditions of the thermal power units are screened to obtain the screened historical data of pollutant emissions.

[0092] Specifically, the stability of each thermal power unit is judged for the pollutant emission historical data obtained in Table 1 above; wherein, the stability characteristics of the thermal power unit are shown in Table 2, including the unit power generation power, main feed water flow, main steam pressure, main steam temperature and reheat steam temperature; the stability characteristic change rate corresponding to the pollutant emission historical data under different load conditions of the thermal power unit is calculated; if the stability characteristic change rate corresponding to the pollutant emission historical data under different load conditions of the thermal power unit is greater than the preset change rate value, the pollutant emission historical data under the corresponding load conditions of the thermal power unit is eliminated; otherwise, it is retained; and the screened pollutant emission historical data is obtained.

[0093] Table 2 Unit stability judgment parameters

[0094] Serial number Parameter name unit Preset change rate / 5min 1 Unit load change MW 1.5％ 2 Main water flow t / h 1.5％ 3 Main steam pressure MPa 0.6 4 Main steam temperature ℃ 5 5 Reheat steam temperature ℃ 5

[0095] Taking the change rate of the unit's power generation as an example, if the unit's power generation change rate corresponding to the historical data of pollutant emissions under different load conditions of the thermal power unit is greater than the preset change rate value of 1.5%, the historical data of pollutant emissions under the corresponding load conditions of the thermal power unit will be discarded; otherwise, it will be retained.

[0096] Step 3: Quadratic function fitting of pollutant emission curve

[0097] The quadratic function is used to fit the screened historical data of pollutant emissions to obtain the pollutant emission characteristic curve of the thermal power unit.

[0098] The specific process is as follows:

[0099] Based on the least squares method, a quadratic function of the pollution emissions of thermal power units and the unit load is established; among them, the expression of the quadratic function of the pollutant emissions of thermal power units and the unit load is:

[0100] M=f(p)=a1p 2 +a2p+a3

[0101] Among them, M is the pollutant emission of the thermal power unit; a1 is the quadratic term coefficient of the quadratic function; a2 is the linear term coefficient of the quadratic function; a3 is the constant term coefficient of the quadratic function; and p is the load of the thermal power unit.

[0102] Step 4: According to the pollutant emission characteristic curve of the thermal power unit, the specific differences in pollutant emissions of different thermal power units are obtained, that is, the analysis results of the pollutant emission characteristics of the thermal power units are obtained; wherein, according to the pollutant emission characteristic curve of the thermal power unit, the pollutant emission values ​​under different load conditions can be intuitively obtained, and the pollutant emission characteristic curves of different thermal power units can be compared, thereby obtaining the specific differences of each thermal power unit.

[0103] In this embodiment, the historical data of a 350MW subcritical unit is screened and the SO2, NOX, and smoke inlet and outlet emission curves calculated by quadratic function fitting are as follows: Figure 2-7 As shown, through real-time monitoring and analysis of each curve, the optimal operating environment of pollutants under different operating conditions can be obtained, which not only lays a solid data foundation for the good operation of the unit, but also provides technical support for the economic allocation and optimal scheduling of the unit.

[0104] From the attached Figure 2-7 It can be seen that the SO2 inlet and outlet emissions and NO X The most reasonable level of inlet and outlet emissions and smoke and dust inlet and outlet emissions; Figure 2-7 The curve characteristics fitted in the model can provide a basis for the economic allocation and optimal scheduling of thermal power units. At the same time, a monitoring system with functions such as pollutant index display and pollutant emission curve is formed, which improves the centralized control capability of pollutants in power plants.

[0105] The description of the relevant parts of the thermal power unit pollutant emission characteristics analysis system, equipment and computer-readable storage medium provided in this embodiment can be found in the detailed description of the corresponding parts of a thermal power unit pollutant emission characteristics analysis method described in this embodiment, and will not be repeated here.

[0106] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A method for analyzing pollutant emission characteristics of thermal power units, characterized in that: The following steps are involved: Obtain historical data on pollutant emissions from thermal power units under different load conditions; According to the stability characteristics of thermal power units, the historical data of pollutant emissions under different load conditions of thermal power units are screened to obtain the screened historical data of pollutant emissions; According to the stability characteristics of thermal power units, the historical data of pollutant emissions under different load conditions of thermal power units are screened to obtain the screened historical data of pollutant emissions. The specific process is as follows: Determine the stability characteristics of thermal power units; Calculate the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of thermal power units; If the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of the thermal power unit is greater than the preset change rate value, the historical data of pollutant emissions under the corresponding load conditions of the thermal power unit are eliminated; otherwise, they are retained; and the filtered historical data of pollutant emissions are obtained; The pollutant emission characteristic curve of the thermal power unit is obtained by fitting the filtered historical data of pollutant emission using quadratic function; The process of fitting the filtered pollutant emission historical data using quadratic functions to obtain the pollutant emission characteristic curve of thermal power units is as follows: Based on the least squares method, a quadratic function between the pollution emission of thermal power units and the unit load is established; The quadratic function of the pollutant emission of the thermal power unit and the unit load is used to fit the selected historical data of pollutant emission to obtain the characteristic curve of the pollutant emission of the thermal power unit; The expression of the quadratic function of the pollutant emissions of thermal power units and unit load is: <h2 style=";text-align:left;direction:ltr">M = f(p) = a1p<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +a2p+a3 Wherein, M is the pollutant emission of the thermal power unit; a1 is the quadratic term coefficient of the quadratic function; a2 is the linear term coefficient of the quadratic function; a3 is the constant term coefficient of the quadratic function; p is the load of the thermal power unit; According to the pollutant emission characteristic curve of the thermal power unit, the specific differences of pollutant emissions of different thermal power units are obtained, that is, the analysis results of the pollutant emission characteristics of the thermal power unit are obtained.

2. A method for analyzing pollutant emission characteristics of a thermal power unit according to claim 1, characterized in that: The historical data of pollutant emissions under different load conditions of the thermal power unit are the historical data of pollutant emissions at several load points of the thermal power unit; wherein the several load points are evenly distributed between the minimum load and the maximum load of the thermal power unit.

3. A method for analyzing pollutant emission characteristics of a thermal power unit according to claim 1, characterized in that: The historical data of pollutant emissions under different load conditions of thermal power units include SO2 emissions, NO X One of emissions and smoke emissions.

4. A method for analyzing pollutant emission characteristics of a thermal power unit according to claim 1, characterized in that: The stability characteristics of thermal power units include unit power generation, main feed water flow, main steam pressure, main steam temperature and reheat steam temperature.

5. A system for analyzing pollutant emission characteristics of thermal power units, characterized in that: include: A historical data acquisition module is used to obtain historical data of pollutant emissions under different load conditions of thermal power units; A screening module is used to screen the historical data of pollutant emissions under different load conditions of the thermal power units according to the stability characteristics of the thermal power units, and obtain the screened historical data of pollutant emissions; According to the stability characteristics of thermal power units, the historical data of pollutant emissions under different load conditions of thermal power units are screened to obtain the screened historical data of pollutant emissions. The specific process is as follows: Determine the stability characteristics of thermal power units; Calculate the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of thermal power units; If the stability characteristic change rate corresponding to the historical data of pollutant emissions under different load conditions of the thermal power unit is greater than the preset change rate value, the historical data of pollutant emissions under the corresponding load conditions of the thermal power unit will be eliminated; otherwise, it will be retained; Obtain filtered historical data of pollutant emissions; A fitting calculation module is used to fit the filtered pollutant emission historical data using a quadratic function to obtain a pollutant emission characteristic curve of the thermal power unit; The process of fitting the filtered pollutant emission historical data using quadratic functions to obtain the pollutant emission characteristic curve of thermal power units is as follows: Based on the least squares method, a quadratic function between the pollution emission of thermal power units and the unit load is established; The quadratic function of the pollutant emission of the thermal power unit and the unit load is used to fit the selected historical data of pollutant emission to obtain the characteristic curve of the pollutant emission of the thermal power unit; The expression of the quadratic function of the pollutant emissions of thermal power units and unit load is: <h2 style=";text-align:left;direction:ltr">M = f(p) = a1p<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +a2p+a3 Wherein, M is the pollutant emission of the thermal power unit; a1 is the quadratic term coefficient of the quadratic function; a2 is the linear term coefficient of the quadratic function; a3 is the constant term coefficient of the quadratic function; p is the load of the thermal power unit; The curve analysis module is used to obtain the specific differences in pollutant emissions of different thermal power units based on the pollutant emission characteristic curve of the thermal power unit, that is, to obtain the analysis results of the pollutant emission characteristics of the thermal power unit.

6. A pollutant emission characteristic analysis device for thermal power units, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the method for analyzing pollutant emission characteristics of a thermal power unit as described in any one of claims 1 to 4 when executing the computer program.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for analyzing pollutant emission characteristics of a thermal power unit as claimed in any one of claims 1 to 4 are implemented.

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