Gas-steam combined cycle flue gas yellow smoke zero emission method
Patent Information
- Application Number
- CN202310402391.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-14
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2043-04-14
AI Technical Summary
[0003]燃气轮机电厂的GE-PG9351FA型燃气轮机发电机组，目前采用DLN2.0+燃烧器，在机组启动过程中，即使脱硝设备及时投入，若按照典型调峰热态启停过程的启动方式，在发电机并网后，达到脱硝催化剂活性温度之前，仍会存在氮氧化物小时均值超标的情况，且烟气排放中NO2排放浓度占比较高，使得机组排放大量棕黄色烟雾
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Figure CN116611214B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy-saving and emission-reduction power generation equipment technology, and more specifically, to a method for zero emission of flue gas nitrate and yellow smoke from a gas-steam combined cycle system. Background Technology
[0002] With China's economic development and the improvement of people's living standards, the country and the public are paying increasing attention to and emphasizing environmental protection, and the requirements for flue gas emission standards in boilers of power generation units are becoming increasingly stringent. As a result, domestic gas turbine power generation technology has made leaps and bounds in the past decade or so. Gas-steam combined cycle units, with their advantages of high efficiency, low emissions, and flexible operation characteristics, have gradually become an important development direction in the power industry, and more and more combined cycle units are being put into the market.
[0003] The GE-PG9351FA gas turbine generator set in the gas turbine power plant currently uses a DLN2.0+ burner. During the unit startup process, even if the denitrification equipment is put into operation in a timely manner, if the startup method follows a typical peak-shaving hot start-up and shutdown process, after the generator is connected to the grid but before reaching the activation temperature of the denitrification catalyst, the hourly average nitrogen oxide emissions will still exceed the standard. Furthermore, the NO2 emission concentration in the flue gas is relatively high, resulting in the unit emitting a large amount of brownish-yellow fumes. Therefore, how to ensure that the unit's nitrogen oxide emissions meet regulations and control the total nitrogen oxide and NO2 concentrations during the initial startup phase is a technical problem that needs to be solved. Summary of the Invention
[0004] The present invention aims to address the above-mentioned deficiencies and provide a method for zero emission of flue gas nitrate and yellow smoke from a combined gas-steam cycle system.
[0005] To overcome the deficiencies in the prior art, the technical solution adopted by the present invention to solve its technical problem includes:
[0006] Obtain typical peak-shaving operating conditions of the unit, and determine the unit start-up time based on the typical peak-shaving operating conditions of the unit;
[0007] The ignition time is determined based on the unit startup time, and the generator grid connection time is determined based on the ignition time.
[0008] Obtain the ambient temperature and determine the average warm-up load based on the ambient temperature;
[0009] Obtain the exhaust gas temperature, and adjust the average warm-up load based on the exhaust gas temperature, adjusting the current warm-up load of the gas turbine towards the average warm-up load;
[0010] Establish a curve of emission concentration values changing over time, and adjust the current warm-up load based on the emission concentration value curve;
[0011] Obtain the inlet temperature of the denitrification system, calculate the rate of change of the inlet temperature of the denitrification system, and determine the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system.
[0012] Furthermore, determining the unit start-up time based on typical peak-shaving operating conditions includes:
[0013] Obtain the minute emissions of pollutants corresponding to the unit's ignition time under typical peak-shaving operating conditions;
[0014] The hourly and next hourly averages of emissions under typical peak-shaving conditions at different ignition times are simulated based on the minute emission rates of the emissions.
[0015] The standard ignition time is determined based on the hourly average and the next hourly average of the emissions, when all emissions are within the standard limits.
[0016] The unit start-up time is determined based on the standard ignition time.
[0017] Furthermore, if there are multiple standard ignition times corresponding to the hourly average and the next hourly average of the emissions not exceeding the standard, then the median of the multiple ignition times is calculated, and the median is determined as the standard ignition time.
[0018] Furthermore, determining the average warm-up load based on ambient temperature includes:
[0019] Set a preset ambient temperature matrix T and a preset average heating load matrix A. For the preset average heating load matrix A, set A(A1, A2, A3, A4), where A1 is the first preset average heating load, A2 is the second preset average heating load, A3 is the third preset average heating load, and A4 is the fourth preset average heating load, and A1 < A2 < A3 < A4.
[0020] For the preset ambient temperature matrix T, set T(T1, T2, T3, T4), where T1 is the first preset ambient temperature, T2 is the second preset ambient temperature, T3 is the third preset ambient temperature, T4 is the fourth preset ambient temperature, and T1 < T2 < T3 < T4.
[0021] The corresponding average warm-up load is selected based on the relationship between the current ambient temperature H and the preset ambient temperature matrix T.
[0022] When H < T1, the fourth preset average warm-up load A4 is selected as the average warm-up load;
[0023] When T1≤H<T2, the third preset average warm-up load A3 is selected as the average warm-up load;
[0024] When T2≤H<T3, the second preset average warm-up load A2 is selected as the average warm-up load;
[0025] When T3≤H<T4, the first preset average warm-up load A1 is selected as the average warm-up load.
[0026] Furthermore, the step of correcting the average warm-up load based on the exhaust gas temperature includes:
[0027] Set a preset exhaust temperature matrix Y and a preset average warm-up load correction coefficient matrix B. For the preset average warm-up load correction coefficient matrix B, set B(B1,B2,B3,B4), where B1 is the first preset average warm-up load correction coefficient, B2 is the second preset average warm-up load correction coefficient, B3 is the third preset average warm-up load correction coefficient, and B4 is the fourth preset average warm-up load correction coefficient, and 0.5 < B1 < B2 < B3 < B4 < 1.5;
[0028] For the preset smoke exhaust temperature matrix Y, set Y(Y1,Y2,Y3,Y4), where Y1 is the first preset smoke exhaust temperature, Y2 is the second preset smoke exhaust temperature, Y3 is the third preset smoke exhaust temperature, Y4 is the fourth preset smoke exhaust temperature, and Y1 < Y2 < Y3 < Y4.
[0029] Based on the relationship between the current exhaust temperature L and the exhaust temperature matrix Y, a corresponding correction coefficient is selected to correct the i-th preset average warm-up load, i = 1, 2, 3, 4;
[0030] When L < Y1, the fourth preset average warm-up load correction coefficient B4 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B4;
[0031] When Y1≤L<Y2, the third preset average warm-up load correction coefficient B3 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B3;
[0032] When Y2≤L<Y3, the second preset average warm-up load correction coefficient B2 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B2;
[0033] When Y3≤L<Y4, the first preset average warm-up load correction coefficient B1 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B1.
[0034] Furthermore, adjusting the current warm-up load based on the emission concentration curve includes:
[0035] Map the emission concentration curves to emission concentration curves under typical peak-shaving conditions;
[0036] If the current emission concentration exceeds the first preset threshold of the emission concentration curve under typical peak-shaving conditions, the current warm-up load will be adjusted according to the excess value.
[0037] Furthermore, determining the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system includes:
[0038] Obtain the inlet temperature of the denitrification system over a given period of time;
[0039] A variation curve was established based on the relationship between the inlet temperature of the denitrification system and time.
[0040] Calculate the rate of change of inlet temperature based on the aforementioned change curve;
[0041] Predict the time required for the inlet temperature to reach the preset temperature based on the inlet temperature change rate.
[0042] Obtain the frequency of the solution pump and the valve opening of the denitrification system, and calculate the time for complete catalyst introduction;
[0043] Calculate the difference between the time required for the inlet temperature to reach the preset temperature and the time required for the catalyst to be fully introduced, and determine the difference as the catalyst introduction time.
[0044] Furthermore, the method also includes:
[0045] Data simulation and deduction are performed based on the control of various indicators during the unit startup process;
[0046] Based on the data simulation results, the optimal values of each indicator during the computer group startup process are obtained;
[0047] A theoretical model for unit startup is established based on the optimal values of each indicator;
[0048] Compare the differences between various indicators during the actual unit startup process and the theoretical startup model of the unit;
[0049] If the difference value is less than the second preset threshold, the operating conditions during the actual start-up process of the unit will be updated to the typical peak-shaving operating conditions of the unit.
[0050] Furthermore, the method also includes: when the unit is shut down, closing the waste heat boiler chimney damper and insulating the waste heat boiler.
[0051] By applying the above technical solutions, this invention provides a more reasonable unit start-up optimization strategy by adjusting the unit start-up time, unit warm-up load value, and denitrification system input parameters. This reduces nitrogen oxide emissions and NO2 concentration in flue gas, ensuring that the nitrogen oxide emissions of the combined cycle unit still meet the standards in the initial stage of start-up, and achieving the beneficial effect of zero emissions of nitrogen oxide smoke throughout the entire start-up process. Attached Figure Description
[0052] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0053] Figure 1 The diagram shows a flow chart of a method for zero emission of flue gas nitrate and yellow smoke from a combined gas-steam cycle system, as proposed in an embodiment of the present invention. Detailed Implementation
[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0055] This application provides a method for zero emission of flue gas nitrate and yellow smoke from a combined gas-steam cycle system, such as... Figure 1 As shown, the method includes the following steps:
[0056] S101, Obtain typical peak-shaving operating conditions of the unit, and determine the unit start-up time based on the typical peak-shaving operating conditions of the unit;
[0057] In some embodiments of this application, determining the unit start-up time based on typical peak-shaving operating conditions includes:
[0058] Obtain the minute emissions of pollutants corresponding to the unit's ignition time under typical peak-shaving operating conditions;
[0059] The hourly and next hourly averages of emissions under typical peak-shaving conditions at different ignition times are simulated based on the minute emission rates of the emissions.
[0060] The standard ignition time is determined based on the hourly average and the next hourly average of the emissions, when all emissions are within the standard limits.
[0061] The unit start-up time is determined based on the standard ignition time.
[0062] In some embodiments of this application, if there are multiple standard ignition times corresponding to the hourly average and the next hourly average of the emissions not exceeding the standard, the median of the multiple ignition times is calculated and the median is determined as the standard ignition time.
[0063] The combined cycle unit used in this embodiment is equipped with an SCR denitrification system. Because there is a 30-40 minute vacuum period between unit startup and ignition and the SCR catalyst reaching its activation temperature, nitrogen oxide emissions exceed standards and yellow smoke is emitted during this vacuum period. Therefore, this embodiment optimizes the unit startup time to ensure that the hourly average nitrogen oxide emissions during the vacuum period meet the standards. The measured minute emissions of nitrogen oxides under typical peak-shaving conditions are detected, and these measured values are substituted into the conversion formula NO. x (15% O2) = NO x The converted value is calculated using *(20.9% - 15%) / (20.9% - O2%). By shifting the converted value forward and backward, typical peak-shaving conditions under different start-up times of the unit are simulated. The hourly average value of nitrogen oxides under typical peak-shaving conditions under different start-up times is simulated, and the ignition time when the nitrogen oxide emission concentration does not exceed the standard for both the current hourly average and the next hourly average is detected (according to the Jiangsu Province Standard for Air Pollutant Emissions from Stationary Gas Turbines, the nitrogen oxide emission of in-service units in 2023 is required to be no more than 30 mg / m³). 3 In this embodiment, the unit startup process is program-controlled, and the time difference between startup time and ignition time is about 15 minutes. Therefore, the startup time can be determined based on the ignition time to ensure that the average concentration of nitrogen oxide emissions in the current hour and the average concentration in the next hour do not exceed the standard. However, the startup time determination method in this embodiment often results in multiple startup times. In order to ensure that emissions meet the standards, this embodiment selects the median of multiple ignition times and determines the median as the standard ignition time.
[0064] S102, determine the ignition time based on the unit startup time, and determine the generator grid connection time based on the ignition time;
[0065] In this embodiment, the unit startup process is program-controlled. The time difference between startup time and ignition time and the time difference between ignition time and generator grid connection time are both about 15 minutes. Therefore, the startup time and grid connection time can be determined based on the ignition time.
[0066] S103, acquire the ambient temperature, and determine the average warm-up load based on the ambient temperature;
[0067] In some embodiments of this application, determining the average warm-up load based on ambient temperature includes:
[0068] Set a preset ambient temperature matrix T and a preset average heating load matrix A. For the preset average heating load matrix A, set A(A1, A2, A3, A4), where A1 is the first preset average heating load, A2 is the second preset average heating load, A3 is the third preset average heating load, and A4 is the fourth preset average heating load, and A1 < A2 < A3 < A4.
[0069] For the preset ambient temperature matrix T, set T(T1, T2, T3, T4), where T1 is the first preset ambient temperature, T2 is the second preset ambient temperature, T3 is the third preset ambient temperature, T4 is the fourth preset ambient temperature, and T1 < T2 < T3 < T4.
[0070] The corresponding average warm-up load is selected based on the relationship between the current ambient temperature H and the preset ambient temperature matrix T.
[0071] When H < T1, the fourth preset average warm-up load A4 is selected as the average warm-up load;
[0072] When T1≤H<T2, the third preset average warm-up load A3 is selected as the average warm-up load;
[0073] When T2≤H<T3, the second preset average warm-up load A2 is selected as the average warm-up load;
[0074] When T3≤H<T4, the first preset average warm-up load A1 is selected as the average warm-up load.
[0075] In this embodiment, after the generator is connected to the grid, the average warm-up load can be determined by detecting the ambient temperature. The higher the ambient temperature, the lower the warm-up load should be to prevent excessive NO2 emission concentration from causing the emission of nitrous oxide fumes.
[0076] S104, Obtain the exhaust gas temperature, and adjust the average warm-up load according to the exhaust gas temperature, adjusting the current warm-up load of the gas turbine to the average warm-up load;
[0077] In some embodiments of this application, the step of correcting the average warm-up load based on the exhaust gas temperature includes:
[0078] Set a preset exhaust temperature matrix Y and a preset average warm-up load correction coefficient matrix B. For the preset average warm-up load correction coefficient matrix B, set B(B1,B2,B3,B4), where B1 is the first preset average warm-up load correction coefficient, B2 is the second preset average warm-up load correction coefficient, B3 is the third preset average warm-up load correction coefficient, and B4 is the fourth preset average warm-up load correction coefficient, and 0.5 < B1 < B2 < B3 < B4 < 1.5;
[0079] For the preset smoke exhaust temperature matrix Y, set Y(Y1,Y2,Y3,Y4), where Y1 is the first preset smoke exhaust temperature, Y2 is the second preset smoke exhaust temperature, Y3 is the third preset smoke exhaust temperature, Y4 is the fourth preset smoke exhaust temperature, and Y1 < Y2 < Y3 < Y4.
[0080] Based on the relationship between the current exhaust temperature L and the exhaust temperature matrix Y, a corresponding correction coefficient is selected to correct the i-th preset average warm-up load, i = 1, 2, 3, 4;
[0081] When L < Y1, the fourth preset average warm-up load correction coefficient B4 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B4;
[0082] When Y1≤L<Y2, the third preset average warm-up load correction coefficient B3 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B3;
[0083] When Y2≤L<Y3, the second preset average warm-up load correction coefficient B2 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B2;
[0084] When Y3≤L<Y4, the first preset average warm-up load correction coefficient B1 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai*B1.
[0085] In this embodiment, the average warm-up load is corrected by detecting the exhaust temperature of the unit. At the beginning of operation, the exhaust temperature is low, and the average warm-up load is corrected by a correction factor to accelerate the rate of exhaust temperature increase. Once the exhaust temperature exceeds 500°C, the average warm-up load is corrected by a correction factor to adjust the warm-up load back to the average warm-up load and reduce the exhaust temperature. Since the slight change in the exhaust temperature of the gas turbine at 500°C has little impact on raising the temperature before the denitrification catalyst to the activation temperature, by controlling the flue gas temperature below 500°C, the overall nitrogen oxide emission level before the denitrification system is put into operation can be effectively reduced, alleviating the emission control pressure in the two hours before and after grid connection.
[0086] S105, Establish a curve of emission concentration values changing over time, and adjust the current warm-up load based on the emission concentration value curve;
[0087] In some embodiments of this application, adjusting the current warm-up load based on the emission concentration curve includes:
[0088] Map the emission concentration curves to emission concentration curves under typical peak-shaving conditions;
[0089] If the current emission concentration exceeds the first preset threshold of the emission concentration curve under typical peak-shaving conditions, the current warm-up load will be adjusted according to the excess value.
[0090] In this embodiment, the emission concentration conversion curve of nitrogen oxides under typical peak-shaving conditions is obtained, and the nitrogen oxide conversion value under the current conditions is monitored and calculated in real time. The nitrogen oxide emission concentration curve is plotted. If the current emission amount is found to deviate abnormally from the curve and exceeds the first preset threshold, the current warm-up load is adjusted in time to ensure that the emission meets the standards.
[0091] S106, Obtain the inlet temperature of the denitrification system, calculate the rate of change of the inlet temperature of the denitrification system, and determine the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system.
[0092] In some embodiments of this application, determining the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system includes:
[0093] Obtain the inlet temperature of the denitrification system over a given period of time;
[0094] A variation curve was established based on the relationship between the inlet temperature of the denitrification system and time.
[0095] Calculate the rate of change of inlet temperature based on the aforementioned change curve;
[0096] Predict the time required for the inlet temperature to reach the preset temperature based on the inlet temperature change rate.
[0097] Obtain the frequency of the solution pump and the valve opening of the denitrification system, and calculate the time for complete catalyst introduction;
[0098] Calculate the difference between the time required for the inlet temperature to reach the preset temperature and the time required for the catalyst to be fully introduced, and determine the difference as the catalyst introduction time.
[0099] In this embodiment, the inlet temperature of the denitrification system is monitored in real time, and a curve of the inlet temperature changing over time is established. The rate of change of the inlet temperature can be calculated by the rate of change of the curve, and the growth trend of the inlet temperature can be predicted. After obtaining enough data, the time for the inlet temperature to reach the preset temperature can be predicted. The preset temperature is the optimal activity temperature of the catalyst. By obtaining the frequency of the solution pump and the valve opening of the denitrification system, the time for the catalyst to be fully introduced is calculated. The time for the catalyst to be fully introduced is obtained by subtracting the time for the catalyst to be fully introduced from the time for the inlet temperature to reach the preset temperature. Appropriately advancing the catalyst introduction time improves the working efficiency of the denitrification system and alleviates the emission control pressure in the two hours before and after grid connection.
[0100] Some embodiments of this application also include:
[0101] Data simulation and deduction are performed based on the control of various indicators during the unit startup process;
[0102] Based on the data simulation results, the optimal values of each indicator during the computer group startup process are obtained;
[0103] A theoretical model for unit startup is established based on the optimal values of each indicator;
[0104] Compare the differences between various indicators during the actual unit startup process and the theoretical startup model of the unit;
[0105] If the difference value is less than the second preset threshold, the operating conditions during the actual start-up process of the unit will be updated to the typical peak-shaving operating conditions of the unit.
[0106] In this embodiment, after the unit stops operating, the unit operating condition indicators adjusted by the method of this application embodiment are obtained, including start-up time, average warm-up load, catalyst injection time of the denitrification system and corresponding nitrogen oxide emission concentration. The above indicators are analyzed by data extrapolation, and the optimal values of each indicator during the start-up process are obtained through optimization. A theoretical model of unit start-up is established based on the optimal values of the indicators, and the difference between the theoretical model and the actual indicators is calculated. In this embodiment, the difference between each indicator is calculated by chi-square test. The smaller the difference, the closer the actual indicator is to the theoretical indicator. If the difference is less than the second preset threshold, the typical peak-shaving condition can be updated according to the current indicators.
[0107] In some embodiments of this application, the method further includes: closing the waste heat boiler chimney damper and insulating the waste heat boiler when the unit is shut down.
[0108] In this embodiment, daily peak shaving of the unit and enhanced boiler insulation can significantly improve catalyst activity, thereby significantly reducing NO2 emission concentration during startup.
[0109] To further illustrate the technical concept of this invention, the technical solution of this invention will now be described in conjunction with specific application scenarios.
[0110] By applying the above technical solutions, the unit startup time is optimized based on the nitrogen oxide emission concentration under typical peak-shaving conditions, ensuring that the hourly average nitrogen oxide emission of the unit meets the standards. Furthermore, by monitoring ambient temperature and flue gas temperature, the unit's warm-up load is reset, and adjustments are made to the warm-up load through real-time monitoring of emission concentrations to ensure emissions do not exceed standards. After the generator is connected to the grid, real-time monitoring of the inlet temperature of the denitrification system allows for timely catalyst injection, improving the system's efficiency and facilitating subsequent control. Additionally, timely insulation measures are taken for the waste heat boiler after unit shutdown to enhance catalyst activity, ensuring that the combined cycle unit's nitrogen oxide emissions still meet standards during the initial startup phase, achieving zero emissions of nitrogen oxides and yellow smoke throughout the entire startup process.
[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for zero emission of flue gas nitrate and yellow smoke from a combined gas-steam cycle system, characterized in that, The method includes: Obtain typical peak-shaving operating conditions of the unit, and determine the unit start-up time based on the typical peak-shaving operating conditions of the unit; The ignition time is determined based on the unit startup time, and the generator grid connection time is determined based on the ignition time. Obtain the ambient temperature and determine the average warm-up load based on the ambient temperature; Obtain the exhaust gas temperature, and adjust the average warm-up load based on the exhaust gas temperature, adjusting the current warm-up load of the gas turbine towards the average warm-up load; Establish a curve of emission concentration values changing over time, and adjust the current warm-up load based on the emission concentration value curve; Obtain the inlet temperature of the denitrification system, calculate the rate of change of the inlet temperature of the denitrification system, and determine the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system. The process of determining the catalyst addition time based on the rate of change of the inlet temperature of the denitrification system includes: Obtain the inlet temperature of the denitrification system over a given period of time; A variation curve was established based on the relationship between the inlet temperature of the denitrification system and time. Calculate the rate of change of inlet temperature based on the aforementioned change curve; Predict the time required for the inlet temperature to reach the preset temperature based on the inlet temperature change rate. Obtain the frequency of the solution pump and the valve opening of the denitrification system, and calculate the time for complete catalyst introduction; Calculate the difference between the time required for the inlet temperature to reach the preset temperature and the time required for the catalyst to be fully introduced, and determine the difference as the catalyst introduction time.
2. The method for zero emission of flue gas nitrate and yellow smoke according to claim 1, characterized in that, The determination of unit start-up time based on typical peak-shaving operating conditions includes: Obtain the minute emissions of pollutants corresponding to the unit's ignition time under typical peak-shaving operating conditions; The hourly and next hourly averages of emissions under typical peak-shaving conditions at different ignition times are simulated based on the minute emission rates of the emissions. The standard ignition time is determined based on the hourly average and the next hourly average of the emissions, when all emissions are within the standard limits. The unit start-up time is determined based on the standard ignition time.
3. The method for zero emission of flue gas nitrate and yellow smoke according to claim 2, characterized in that, If there are multiple standard ignition times corresponding to the hourly average and the next hourly average of the emissions not exceeding the standard, then the median of the multiple ignition times is calculated, and the median is determined as the standard ignition time.
4. The method for zero emission of flue gas nitrate and yellow smoke according to claim 1, characterized in that, The determination of average warm-up load based on ambient temperature includes: Set a preset ambient temperature matrix T and a preset average heating load matrix A. For the preset average heating load matrix A, set A(A1, A2, A3, A4), where A1 is the first preset average heating load, A2 is the second preset average heating load, A3 is the third preset average heating load, and A4 is the fourth preset average heating load, and A1 < A2 < A3 < A4. For the preset ambient temperature matrix T, set T(T1, T2, T3, T4), where T1 is the first preset ambient temperature, T2 is the second preset ambient temperature, T3 is the third preset ambient temperature, T4 is the fourth preset ambient temperature, and T1 < T2 < T3 < T4. The corresponding average warm-up load is selected based on the relationship between the current ambient temperature H and the preset ambient temperature matrix T. When H < T1, the fourth preset average warm-up load A4 is selected as the average warm-up load; When T1≤H<T2, the third preset average warm-up load A3 is selected as the average warm-up load; When T2≤H<T3, the second preset average warm-up load A2 is selected as the average warm-up load; When T3≤H<T4, the first preset average warm-up load A1 is selected as the average warm-up load.
5. The method for zero emission of flue gas nitrate and yellow smoke according to claim 4, characterized in that, The method of correcting the average warm-up load based on the exhaust gas temperature includes: Set a preset exhaust temperature matrix Y and a preset average warm-up load correction coefficient matrix B. For the preset average warm-up load correction coefficient matrix B, set B(B1,B2,B3,B4), where B1 is the first preset average warm-up load correction coefficient, B2 is the second preset average warm-up load correction coefficient, B3 is the third preset average warm-up load correction coefficient, and B4 is the fourth preset average warm-up load correction coefficient, and 0.5 < B1 < B2 < B3 < B4 < 1.5; For the preset smoke exhaust temperature matrix Y, set Y(Y1,Y2,Y3,Y4), where Y1 is the first preset smoke exhaust temperature, Y2 is the second preset smoke exhaust temperature, Y3 is the third preset smoke exhaust temperature, Y4 is the fourth preset smoke exhaust temperature, and Y1 < Y2 < Y3 < Y4. Based on the relationship between the current exhaust temperature L and the exhaust temperature matrix Y, a corresponding correction coefficient is selected to correct the i-th preset average warm-up load, i=1,2,3,4; When L < Y1, the fourth preset average warm-up load correction coefficient B4 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai. B4; When Y1≤L<Y2, the third preset average warm-up load correction coefficient B3 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai. B3; When Y2≤L<Y3, the second preset average warm-up load correction coefficient B2 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai. B2; When Y3≤L<Y4, the first preset average warm-up load correction coefficient B1 is selected to correct the i-th preset average warm-up load, and the corrected average warm-up load is Ai. B1.
6. The method for zero emission of flue gas nitrate and yellow smoke according to claim 1, characterized in that, The adjustment of the current warm-up load based on the emission concentration curve includes: Map the emission concentration curves to emission concentration curves under typical peak-shaving conditions; If the current emission concentration exceeds the first preset threshold of the emission concentration curve under typical peak-shaving conditions, the current warm-up load will be adjusted according to the excess value.
7. The method for zero emission of flue gas nitrate and yellow smoke according to claim 1, characterized in that, The method further includes: Data simulation and deduction are performed based on the control of various indicators during the unit startup process; Based on the data simulation results, the optimal values of each indicator during the computer group startup process are obtained; A theoretical model for unit startup is established based on the optimal values of each indicator; Compare the differences between various indicators during the actual unit startup process and the theoretical startup model of the unit; If the difference value is less than the second preset threshold, the operating conditions during the actual start-up process of the unit will be updated to the typical peak-shaving operating conditions of the unit.
8. The method for zero emission of flue gas nitrate and yellow smoke according to claim 1, characterized in that, The method also includes: when the unit is shut down, closing the waste heat boiler chimney damper and insulating the waste heat boiler.