A method and system for estimating the thermoelectric efficiency curve of a coal-fired power generation unit

Abstract

The present invention discloses a method and system for estimating the thermoelectric efficiency curve of a coal-fired power generation unit, belonging to the technical field of coal-fired power generation. The method includes: obtaining the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired power generation unit, and calculating the main steam inlet specific enthalpy according to the main steam temperature and the main steam pressure; determining the inlet steam heat of the steam turbine according to the main steam inlet specific enthalpy and the main steam flow rate; forming a two-dimensional sample point set based on the inlet steam heat and the actual power generation of the unit, calculating the density value of each sample point therein, and determining the maximum density peak sample point at different powers to construct a characteristic sample point set; performing multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit. The thermoelectric conversion efficiency of the unit in different load sections can be reflected through the thermoelectric conversion efficiency curve, solving the problem that the existing thermoelectric conversion efficiency of the unit is regarded as a fixed value, which affects the operation efficiency of the unit.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation, and particularly to a method and system for estimating the thermoelectric efficiency curve of a coal-fired power generation unit. Background Art

[0002] The statements in this part only mention the background art related to the present invention and do not necessarily constitute the prior art.

[0003] The working principle of a coal-fired power generation unit is mainly to convert the heat energy generated by the combustion of pulverized coal in a boiler into the heat energy of high-temperature and high-pressure steam, then convert the heat energy of the high-temperature and high-pressure steam into the rotational mechanical energy of a steam turbine through the steam turbine, and finally convert the rotational mechanical energy of the blades into electrical energy by a generator coaxially connected to the steam turbine. However, the thermoelectric conversion efficiencies of each unit are different, and the same unit also has different thermoelectric conversion efficiencies at different load segments. Improving the power generation and operation duration of a coal-fired power generation unit at high-efficiency points and reducing the power generation and operation duration at low-efficiency points are crucial for reducing the unit carbon emissions of a coal-fired power generation unit and improving the production efficiency of a coal-fired power generation unit.

[0004] The thermoelectric conversion efficiency of a coal-fired power generation unit is an important unit performance index and an important reference for the unit to adjust its operation mode. At present, it is generally considered that the thermoelectric conversion efficiency of the unit is a fixed design value. However, during the actual operation of the unit, different load segments often have different thermoelectric conversion efficiencies. If the unit operates at a low conversion efficiency point for a long time, it will lead to an increase in the unit carbon emissions of the unit and a decrease in the unit revenue. Summary of the Invention

[0005] To solve the deficiencies of the prior art, the present invention provides a method, system, electronic device, computer-readable storage medium, and computer program product for estimating the thermoelectric efficiency curve of a coal-fired power generation unit. Based on the unit operation data, by estimating the steam inlet heat of the steam turbine and calculating the density peak of the estimated heat result and the unit power generation, combined with multiple regression analysis, the estimated result of the thermoelectric conversion efficiency curve is obtained, which can effectively give the thermoelectric conversion efficiency of the unit at different load segments and provide support information for optimizing the unit operation mode and improving the unit operation efficiency.

[0006] In a first aspect, the present invention provides a method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit;

[0007] A method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit includes:

[0008] Obtain the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired power generation unit. According to the main steam temperature and the main steam pressure, calculate the specific enthalpy of the main steam inlet; according to the specific enthalpy of the main steam inlet and the main steam flow rate, determine the inlet steam heat of the steam turbine;

[0009] Based on the inlet steam heat and the actual power generation of the unit, form a two-dimensional sample point set, calculate the density values of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set;

[0010] Perform multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit.

[0011] In some embodiments, the calculating the specific enthalpy of the main steam inlet according to the main steam temperature and the main steam pressure includes:

[0012] According to the ratio of the main steam pressure to the pressure constant, calculate the ideal gas part and the remaining gas part of the dimensionless Gibbs free energy respectively;

[0013] According to the ideal gas part and the remaining gas part of the dimensionless Gibbs free energy, combined with the main steam temperature, calculate the specific enthalpy of the main steam inlet.

[0014] In some embodiments, the determining the inlet steam heat of the steam turbine according to the specific enthalpy of the main steam inlet and the main steam flow rate is specifically: perform unit conversion on the main steam flow rate and multiply it by the specific enthalpy of the main steam inlet to obtain the inlet steam heat of the steam turbine.

[0015] In some embodiments, the density value is expressed as:

[0016] ,

[0017] where , represents the Euclidean distance between the 、 th sample point and the current 、 th sample point in the two-dimensional sample point set, represents the truncation distance, represents the sign function.

[0018] In some embodiments, the determining the maximum density peak sample points at different powers is specifically: divide the interval of the actual power generation of the unit to obtain multiple unit power division intervals; based on the density value, screen the maximum density peak sample points within the unit power division intervals.

[0019] In some embodiments, the multivariate regression modeling of the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit is specifically as follows: taking the actual power generation of the unit in the characteristic sample point set as the independent variable and the inlet steam heat in the characteristic sample point set as the dependent variable, the least square criterion is used to determine the multivariate linear regression model between the two, and the thermoelectric conversion efficiency curve of the unit is determined.

[0020] In a second aspect, the present invention provides a thermoelectric efficiency curve estimation system for a coal-fired power generation unit;

[0021] A thermoelectric efficiency curve estimation system for a coal-fired power generation unit includes:

[0022] A heat estimation module, configured to: obtain the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired power generation unit, calculate the main steam inlet specific enthalpy according to the main steam temperature and the main steam pressure; determine the inlet steam heat of the steam turbine according to the main steam inlet specific enthalpy and the main steam flow rate;

[0023] A density peak calculation module, configured to: form a two-dimensional sample point set based on the inlet steam heat and the actual power generation of the unit, calculate the density values of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set;

[0024] A thermoelectric efficiency curve estimation module, configured to: perform multivariate regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit.

[0025] In a third aspect, the present invention provides an electronic device;

[0026] An electronic device includes a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the above-mentioned thermoelectric efficiency curve estimation method for a coal-fired power generation unit.

[0027] In a fourth aspect, the present invention provides a computer-readable storage medium;

[0028] A computer-readable storage medium, on which a computer program / instructions are stored, and when the computer program / instructions are executed by a processor, the steps of the above-mentioned thermoelectric efficiency curve estimation method for a coal-fired power generation unit are implemented.

[0029] In a fifth aspect, the present invention provides a computer program product;

[0030] A computer program product includes computer program / instructions, and when the computer program / instructions are executed by a processor, the steps of the above-mentioned thermoelectric efficiency curve estimation method for a coal-fired power generation unit are implemented.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The technical solution provided by the present invention estimates the thermoelectric efficiency curve of a coal-fired power generation unit based on the unit operation data that can reflect the true operation state of the unit, which can effectively make up for the deficiencies of the design value in various applications and better conform to the true operation state of the coal-fired power generation unit.

[0033] 2. The technical solution provided by the present invention can effectively reveal the true thermoelectric conversion efficiency of the unit, provide support for optimizing the unit operation mode, and optimize the unit based on this, which can reduce the unit carbon emission and improve the unit revenue.

[0034] 3. The technical solution provided by the present invention requires fewer unit parameters and less dependence on process knowledge, and has the significant advantage of being easy to implement, which has positive significance for the popularization and application of this technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0036] Figure 1 It is a schematic flow chart of the method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit provided by an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the trend of the main steam temperature data provided by an embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the trend of the main steam pressure data provided by an embodiment of the present invention;

[0039] Figure 4 It is a schematic diagram of the trend of the main steam flow rate data provided by an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram of the trend of partial data of the unit load provided by an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of the inlet steam heat sequence provided by an embodiment of the present invention;

[0042] Figure 7 It is a schematic diagram of the actual power generation sequence of the unit provided by an embodiment of the present invention;

[0043] Figure 8 It is a schematic diagram of the two-dimensional sample point set provided by an embodiment of the present invention;

[0044] Figure 9 It is an example diagram of the characteristic sample point set provided by an embodiment of the present invention;

[0045] Figure 10 This is an example diagram of the estimated result of the thermoelectric efficiency curve provided by the embodiment of the present invention. Specific embodiments

[0046] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0048] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0049] Embodiment 1

[0050] At present, it is generally believed that the thermoelectric conversion efficiency of coal-fired power generation units is a fixed value, ignoring the influence of different loads on different thermoelectric conversion efficiencies, resulting in an increase in the unit carbon emissions of the units; therefore, the present invention provides a method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit. Based on the unit operation data, by estimating the inlet steam heat of the steam turbine and performing density peak calculation on the estimated heat result and the actual power generation of the unit to obtain density peak sample points, and then performing multiple regression analysis on the density peak points to obtain the estimated result of the thermoelectric conversion efficiency curve.

[0051] Next, in combination with Figures 1 - 10 , a method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit disclosed in this embodiment will be described in detail. The method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit includes:

[0052] S1. Obtain the main steam temperature data , the main steam pressure data , the main steam flow data and the actual power generation data of the unit at a fixed sampling period.

[0053] For a coal-fired power generation unit whose thermoelectric conversion efficiency curve is to be estimated, obtain the upper and lower limits of the unit power to ensure that the above long-term operation data includes the minimum power generation power to the maximum power generation power during normal operation of the unit and lasts for a long time.

[0054] S2. Use a moving average filter to smooth the main steam temperature data , the main steam pressure data , the main steam flow data and the actual power generation data of the unit respectively, and obtain the filtered main steam temperature data , the main steam pressure data , the main steam flow data and the actual power generation data of the unit .

[0055] Based on this, through the above filtering process, the influence of random fluctuations in the data on the estimation result can be reduced.

[0056] Next, taking the variable main steam temperature as an example, the filtering process of the moving average filter will be further introduced, expressed as:

[0057] ,

[0058] where is the window width of the moving average filter, is the sample ordinal number, is the length of the data.

[0059] In this embodiment, , and can be obtained respectively according to the same principle of the above formula.

[0060] Furthermore, in specific implementation, the window width of the moving smoothing filter should be appropriate to avoid over-smoothing and losing the inherent information in the data; in this step, combined with the characteristics of the coal-fired power generation process, determine the window width of the moving smoothing filter. Exemplarily, the coal-fired power generation unit needs to complete the actual operation requirements of the unit power control instruction within the specified response time of 60 seconds, and there are two stages of dynamic response process and steady-state process during this process, then the window width is recommended to be 30 seconds.

[0061] S3. Calculate the specific enthalpy of the main steam inlet ratio according to the filtered main steam temperature data and the filtered main steam pressure data .

[0062] Specifically, first, according to the filtered main steam pressure data Calculate the ideal gas part and the residual gas part of the dimensionless Gibbs free energy respectively according to the ratio with the pressure constant; then, calculate the main steam inlet specific enthalpy based on the ideal gas part and the residual gas part of the dimensionless Gibbs free energy in combination with the filtered main steam temperature data , and calculate the main steam inlet specific enthalpy.

[0063] Exemplarily, the ideal gas part of the dimensionless Gibbs free energy is expressed as:

[0064] ;

[0065] The residual gas part of the dimensionless Gibbs free energy is expressed as:

[0066] ;

[0067] In the formula, represents the first proportionality coefficient, and its value is ; represents the pressure constant, and its value is 1 Mpa; represents the first coefficient, represents the first exponent, represents the second coefficient, represents the second exponent, i represents the ordinal number.

[0068] The main steam inlet specific enthalpy is expressed as:

[0069] ;

[0070] In the formula, represents the gas constant of ordinary water, ; represents the second proportionality coefficient, and its value is ; represents the temperature constant, and its value is 540 K.

[0071] Here, according to the conclusions in the "IAPWS Announcement on the Calculation Formulas for the Thermodynamic Properties of Industrial Water and Steam in 1997", , The values of can be found in Table 1, , and can be found in Table 2.

[0072] Table 1

[0073]

[0074] Table 2

[0075]

[0076] S4. Determine the inlet steam heat of the steam turbine according to the main steam inlet specific enthalpy and the main steam flow rate.

[0077] Exemplarily, the inlet steam heat of the steam turbine is expressed as:

[0078] ;

[0079] In the formula, represents the unit mass flow rate of the inlet steam, takes the value of the main steam flow rate after being converted to Kg / h (kilograms per hour).

[0080] S5. Based on the inlet steam heat and the actual power generated by the unit, form a two-dimensional sample point set, calculate the density values of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set.

[0081] Here, as Figure 8 shown, with the inlet steam heat as the vertical axis and the actual power generated by the unit as the horizontal axis, the inlet steam heat and the actual power generated by the unit at the same moment are associated to form a two-dimensional sample point set. Using the inlet steam heat and the actual power generated by the unit for the estimation of the thermoelectric conversion efficiency curve avoids the uncertainty caused by coal quality fluctuations to the estimation result of the thermoelectric conversion efficiency curve.

[0082] Exemplarily, for the two-dimensional sample point set its density value of each sample point is expressed as:

[0083] ;

[0084] In the formula, represents the Euclidean distance between the -th and -th sample points in the two-dimensional sample point set and the current -th and -th sample points, represents the cut-off distance, represents the sign function, when is greater than or equal to , when is less than .

[0085] Furthermore, determining the maximum density peak sample points at different powers includes:

[0086] (1)Divide the actual generated power of the unit into intervals to obtain multiple unit power division intervals.

[0087] In order to ensure that the selection of the maximum density peak sample points can not only guarantee the significance of the density peak sample points but also have the distinguishability of power changes, in this embodiment, the width of the power division interval is determined in combination with the characteristics of the amplitude of the unit power control command.

[0088] Specifically, the change amplitude of the unit power control command should be significantly greater than the random fluctuations in the actual generated power data. According to the dead zone width of the power control command adopted by the generator set, the random fluctuation operating range of the actual generated power data, and the sum of 6 times the measurement noise standard deviation in the actual generated power data, the width of the power division interval can be determined, where the measurement noise standard deviation in the actual generated power data is determined based on the 3-Sigma principle.

[0089] Exemplarily, if the current commonly adopted dead zone width of the power control command of the generator set is 1MW, the random fluctuation operating range of the actual generated power data is 1MW, and 6 times the measurement noise standard deviation in the actual generated power data is 0.7MW, then the width of the power division interval can be 2.7MW.

[0090] (2)Based on the density values of each sample point, screen the maximum density peak sample points within the unit power division interval to form a characteristic sample point set, which is expressed as:

[0091] ;

[0092] Among them, and respectively represent the upper and lower limits of the th unit power division interval, and represents the function of finding the independent variable that makes the function reach the maximum value.

[0093] Based on this, by selecting the maximum density peak sample points, the influence of the corresponding two-dimensional sample points of the unit under abnormal conditions, manual operation, random fluctuations, etc. on the estimation result can be avoided.

[0094] S6. Perform multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit.

[0095] Specifically, taking the actual generated power points of the unit in the characteristic sample point set as the independent variable and the inlet steam heat points in the characteristic sample point set as the dependent variable, the least squares criterion is used to determine the multiple linear regression model between the two, and the obtained model is the thermoelectric conversion efficiency curve of the unit.

[0096] In this embodiment, in order to avoid overfitting and underfitting, the model order can be set from 2nd order to 3rd order.

[0097] Further, the thermoelectric conversion efficiency curve can be expressed as:

[0098] ;

[0099] In the formula, , , …, represent the regression model parameters.

[0100] Next, in order to prove the effectiveness of the solution described in this embodiment, relevant experimental verification is carried out by taking the estimation of the thermoelectric conversion efficiency curve of a 200MW coal-fired unit as an example, and the specific effect of the method described in this embodiment in practical applications is illustrated. The specific process is as follows:

[0101] Step 1: Obtain the main steam temperature , main steam pressure , main steam flow rate and the actual power generation of the unit for 30 consecutive days of operation data. Part of the obtained data is as Figures 2 - 5 shown.

[0102] Step 2: Let the window width of the moving average filter , and perform smoothing filtering on the obtained main steam temperature data, main steam pressure data, main steam flow rate data and actual power generation data of the unit respectively to obtain the filtered main steam temperature data , main steam pressure data , main steam flow rate data and the actual power generation data of the unit .

[0103] Step 3: According to the filtered main steam temperature data and main steam pressure data , calculate the main steam inlet specific enthalpy , and then from the main steam inlet specific enthalpy and the filtered main steam flow rate data , calculate the steam inlet heat sequence of the steam turbine , as Figure 6 shown; by comparing Figure 6 with the trend of the curve in Figure 7 , it can be found that the trends of the two curves are similar, indicating the rationality of the obtained steam inlet heat sequence.

[0104] Step 4: Use the steam inlet heat sequence and the actual power generation sequence to form a two-dimensional sample point set , as Figure 8as shown by the blue dots; and divide the actual power generation range of the unit by 2.7MW, then determine the maximum density peak sample points in each actual power generation range, and form a characteristic sample point set with all the obtained maximum density peak sample points, such as Figure 9 as shown by the red dots in

[0105] Step 5: Build a multiple regression model for the obtained characteristic sample point set to obtain the thermoelectric conversion efficiency curve of the unit, and its analytical expression is:

[0106] .

[0107] The thermoelectric conversion efficiency curve of the unit is as shown by the black curve in Figure 10 As can be seen from the thermoelectric conversion efficiency curve obtained in Figure 10 , the coal-fired generating unit has a slightly higher thermoelectric conversion efficiency in the low load section than in the high load section.

[0108] Embodiment 2

[0109] This embodiment discloses a system for estimating the thermoelectric efficiency curve of a coal-fired generating unit, including:

[0110] A heat estimation module, configured to: obtain the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired generating unit, calculate the main steam inlet specific enthalpy according to the main steam temperature and the main steam pressure; determine the inlet steam heat of the steam turbine according to the main steam inlet specific enthalpy and the main steam flow rate;

[0111] A density peak calculation module, configured to: form a two-dimensional sample point set based on the inlet steam heat and the actual power generation of the unit, calculate the density values of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set;

[0112] A thermoelectric efficiency curve estimation module, configured to: perform multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit.

[0113] It should be noted here that the above heat estimation module, density peak calculation module and thermoelectric efficiency curve estimation module correspond to the steps in Embodiment 1. The examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the content disclosed in Embodiment 1 above. It should be noted that the above modules, as part of the system, can be executed in a computer system such as a set of computer executable instructions.

[0114] Embodiment 3

[0115] Embodiment 3 of the present invention provides an electronic device, including a memory, a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of the above-mentioned method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit are completed.

[0116] Embodiment 4

[0117] Embodiment 4 of the present invention provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the steps of the above-mentioned method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit are completed.

[0118] Embodiment 5

[0119] Embodiment 5 of the present invention provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the above-mentioned method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit are implemented.

[0120] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0121] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device, and a series of operation steps are executed on the computer or other programmable device to generate computer-implemented processing. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0123] In the above embodiments, the descriptions of the various embodiments each have their own emphasis. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0124] The foregoing is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit, characterized in that, Including: Obtain the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired power generation unit. According to the main steam temperature and the main steam pressure, calculate the specific enthalpy of the main steam inlet; according to the specific enthalpy of the main steam inlet and the main steam flow rate, determine the inlet steam heat of the steam turbine; Based on the inlet steam heat and the actual power generation of the unit, form a two-dimensional sample point set, calculate the density value of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set; The determination of the maximum density peak sample points at different powers is specifically: divide the range of the actual power generation of the unit to obtain multiple unit power division ranges; based on the density value, screen the maximum density peak sample points within the unit power division range; Specifically, according to the sum of the dead zone width of the power control command adopted by the power generation unit, the random fluctuation operation range of the actual power generation data, and 6 times the measurement noise standard deviation in the actual power generation data, determine the width of the power division range; Based on the density value of each sample point, screen the maximum density peak sample points within the unit power division range to form a characteristic sample point set; Perform multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit; The performing multiple regression modeling on the characteristic sample point set to generate the thermoelectric conversion efficiency curve of the unit is specifically: use the actual power generation of the unit in the characteristic sample point set as the independent variable, use the inlet steam heat in the characteristic sample point set as the dependent variable, and adopt the least squares criterion to determine the multiple linear regression model between the two, set the model order to 2nd to 3rd order, and determine the thermoelectric conversion efficiency curve of the unit.

2. The method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to claim 1, wherein The calculating the specific enthalpy of the main steam inlet according to the main steam temperature and the main steam pressure includes: According to the ratio of the main steam pressure to the pressure constant, calculate the ideal gas part and the remaining gas part of the dimensionless Gibbs free energy respectively; According to the ideal gas part and the remaining gas part of the dimensionless Gibbs free energy, combined with the main steam temperature, calculate the specific enthalpy of the main steam inlet.

3. The method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to claim 1, characterized in that, The determining the inlet steam heat of the steam turbine according to the specific enthalpy of the main steam inlet and the main steam flow rate is specifically: perform unit conversion on the main steam flow rate and multiply it by the specific enthalpy of the main steam inlet to obtain the inlet steam heat of the steam turbine.

4. The method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to claim 1, wherein The density value is expressed as: ； In the formula, represents the Euclidean distance between the -th and -th sample points in the two-dimensional sample point set and the current -th and -th sample points, represents the truncation distance, represents the sign function.

5. A thermoelectric efficiency curve estimation system for a coal-fired power generation unit, characterized in that Including: A heat estimation module, configured to: obtain the main steam temperature, main steam pressure, main steam flow rate and actual power generation of the coal-fired power generation unit. According to the main steam temperature and the main steam pressure, calculate the specific enthalpy of the main steam inlet; according to the specific enthalpy of the main steam inlet and the main steam flow rate, determine the inlet steam heat of the steam turbine; A density peak calculation module, configured to: based on the inlet steam heat and the actual power generation of the unit, form a two-dimensional sample point set, calculate the density value of each sample point in the two-dimensional sample point set, and determine the maximum density peak sample points at different powers to construct a characteristic sample point set; The specific determination of the maximum density peak sample points at different powers is as follows: the actual generated power of the unit is divided into intervals to obtain multiple unit power division intervals; based on the density values, the maximum density peak sample points are screened within the unit power division intervals; Specifically, according to the dead zone width of the power control command adopted by the generator set, the random fluctuation operation range of the actual generated power data, and the sum of the measurement noise standard deviations in 6 times of the actual generated power data, the width of the power division interval is determined; Based on the density values of each sample point, the maximum density peak sample points are screened within the unit power division intervals to form a characteristic sample point set; A thermoelectric efficiency curve estimation module, configured to: perform multiple regression modeling on the characteristic sample point set to generate a thermoelectric conversion efficiency curve of the unit; The specific process of performing multiple regression modeling on the characteristic sample point set to generate a thermoelectric conversion efficiency curve of the unit is as follows: taking the actual generated power of the unit in the characteristic sample point set as the independent variable and the inlet steam heat in the characteristic sample point set as the dependent variable, using the least square criterion to determine the multiple linear regression model between the two, setting the model order to 2 to 3 orders, and determining the thermoelectric conversion efficiency curve of the unit.

6. An electronic device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that The processor executes the computer program to implement the steps of the method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to any one of claims 1-4.

7. A computer-readable storage medium having computer programs / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, the steps of the method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to any one of claims 1-4 are implemented.

8. A computer program product comprising computer programs / instructions, characterized in that, When the computer program / instructions are executed by the processor, the steps of the method for estimating the thermoelectric efficiency curve of a coal-fired power generation unit according to any one of claims 1-4 are implemented.

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