Flexible circulation upgrading system and control method

Abstract

The invention relates to the technical field of thermal power generation, and particularly discloses a flexible circulation upgrading system and a control method, and the system comprises a boiler which is connected to a steam turbine high-pressure cylinder and is used for conveying main steam to the steam turbine high-pressure cylinder through a main steam pipeline; the hot secondary air assembly is connected to the boiler and used for conveying hot secondary air to the boiler; one section of the steam extraction assembly is connected to the main steam pipeline, the other end of the steam extraction assembly is connected with the hot secondary air assembly, and the steam extraction assembly is used for extracting main steam in the boiler to heat hot secondary air; the industrial heat supply assembly is connected to the hot secondary air assembly and used for conveying steam in the hot secondary air assembly to an industrial heat supply steam inlet; and the high-heating heat supply assembly is connected to the hot secondary air assembly and used for conveying steam in the hot secondary air assembly to a first high-pressure heater, and the first high-pressure heater is connected with the boiler through a high-temperature water supply pipe. The low-load stable combustion effect of the unit is improved, and stable and economical operation of the unit is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of thermal power generation, and more specifically, to a flexible cycle quality improvement system and a control method. Background Art

[0002] Due to the unpredictability of wind power and photovoltaic power, the requirements for stable and safe operation of the power grid will become increasingly higher. Coal is the most important and reliable fossil energy source. The flexibility of coal-fired power plants has a key impact on the overall regulation performance of the power system. With the advancement of the flexibility transformation of coal-fired power units, more and more coal-fired units have begun to carry out deep peak regulation.

[0003] However, with the continuous increase in the total installed capacity of new energy sources, the peak-shaving time of thermal power generating units is getting longer and longer, and the peak-shaving depth is getting deeper. Under such an operating environment, how to achieve stable combustion of boilers under low load and stable operation of SCR denitrification systems has become a major factor affecting the deep peak-shaving of the units. Summary of the invention

[0004] The present invention provides a flexible cycle quality improvement system and control method, which are used to solve the problem of difficulty in low-load stable combustion under deep peak regulation of coal-fired units in the prior art, including:

[0005] A boiler connected to the high-pressure cylinder of the steam turbine and used for conveying main steam to the high-pressure cylinder of the steam turbine through a main steam pipeline;

[0006] a hot secondary air component, connected to the boiler, for conveying hot secondary air to the boiler;

[0007] A steam extraction component, one end of which is connected to the main steam pipeline and the other end of which is connected to the hot secondary air component, and is used to extract the main steam in the boiler to heat the hot secondary air;

[0008] An industrial heating component, connected to the hot secondary air component, for conveying the steam in the hot secondary air component to the industrial heating steam inlet;

[0009] The high-pressure heating component is connected to the hot secondary air component and is used to transport the steam in the hot secondary air component to the No. 1 high-pressure heater. The No. 1 high-pressure heater is connected to the boiler through a high-temperature water supply pipe.

[0010] Furthermore, the hot secondary air component comprises:

[0011] Air preheater;

[0012] The hot secondary air heater is connected to the air preheater via a first hot secondary air duct, and the hot secondary air heater is connected to the boiler via a second hot secondary air duct.

[0013] Furthermore, the steam extraction assembly comprises:

[0014] A steam branch pipe, one end of which is connected to the main steam pipe, and the other end of which is connected to the hot secondary air heater, wherein a first stop valve and a first pressure reducing valve are sequentially arranged on the side of the steam branch pipe close to the main steam pipe;

[0015] The temperature reduction pipeline is connected to the side of the steam branch pipeline away from the main steam pipeline. The temperature reduction pipeline is sequentially provided with a second stop valve, a second pressure reducing valve, a first check valve, and a temperature reducer.

[0016] Furthermore, the industrial heating component comprises:

[0017] The first branch pipeline has one end connected to the hot secondary air heater and the other end connected to the industrial heating steam inlet. The first branch pipeline is sequentially provided with a third stop valve, a third pressure reducing valve, a second check valve, and a fourth stop valve.

[0018] Furthermore, the high-pressure heating component includes:

[0019] A second branch pipeline, one end of which is connected to the hot secondary air heater, and the other end of which is connected to the No. 1 high-pressure heater, and a third check valve and a fifth stop valve are sequentially arranged on the side of the second branch pipeline away from the first branch pipeline;

[0020] A section of steam extraction pipeline is connected to the second branch pipeline.

[0021] In order to achieve the above object, the present invention also provides a control method for a flexible circulation quality improvement system, comprising:

[0022] Obtain the current unit load change value, determine the hot secondary air target temperature according to the current unit load change value, and set the main steam adjustment value of the steam extraction component according to the hot secondary air target temperature;

[0023] Obtaining an industrial heating demand value, and setting a first steam flow adjustment value of the industrial heating component according to the industrial heating demand value;

[0024] Obtain the main steam residual parameters of the hot secondary air component, and set the second steam flow adjustment value of the high-pressure heating component according to the main steam residual parameters of the hot secondary air component.

[0025] Further, determining the target temperature of the hot secondary air according to the target load value of the unit includes:

[0026] Get the boiler temperature value, and draw the current boiler temperature change curve according to the change of boiler temperature value and random group load;

[0027] Obtain historical unit load change values ​​and corresponding boiler temperature change curves, and establish training sets and test sets based on the historical unit load change values ​​and corresponding boiler temperature change curves;

[0028] An initial boiler temperature prediction model is established, and the initial boiler temperature prediction model is trained according to a training set and a test set to obtain a trained boiler temperature prediction model;

[0029] Input the current unit load change value into the trained boiler temperature prediction model to obtain the boiler temperature standard change curve;

[0030] Obtaining the correlation between the current boiler temperature change curve and the boiler temperature standard change curve, calculating the ratio of the correlation between the current boiler temperature change curve and the boiler temperature standard change curve to the preset standard correlation, and obtaining the hot secondary air target temperature correction coefficient;

[0031] The hot secondary air target temperature correction coefficient is multiplied by the preset standard hot secondary air target temperature to obtain the hot secondary air target temperature.

[0032] Further, the main steam adjustment value of the steam extraction component is set according to the hot secondary air target temperature, including:

[0033] Obtaining the hot secondary air temperature of the current hot secondary air component, calculating the difference between the hot secondary air target temperature and the current hot secondary air temperature, and determining whether the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a first preset threshold;

[0034] If the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a first preset threshold, setting the first adjustment parameter as the main steam adjustment value of the steam extraction component;

[0035] If the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the first preset threshold, determining whether the difference between the predicted electricity price and the preset electricity price allowable value is greater than the second preset threshold;

[0036] If the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a second preset threshold, setting the second adjustment parameter as the main steam adjustment value of the steam extraction component;

[0037] If the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the second preset threshold, the third adjustment parameter is set as the main steam adjustment value of the steam extraction component.

[0038] Furthermore, the step of setting the first steam flow adjustment value of the industrial heating component according to the industrial heating demand value includes:

[0039] Determine the industrial heating demand level according to the industrial heating demand value, and determine the corresponding industrial heating demand range according to the industrial heating demand level;

[0040] Determine the industrial heating temperature demand range according to the industrial heating demand range, obtain the steam temperature value entering the industrial heating component, and calculate the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range;

[0041] The first steam flow adjustment value is determined according to the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range.

[0042] Further, the obtaining of the main steam residual parameter of the hot secondary air component and setting the second steam flow adjustment value of the high-pressure heating component according to the main steam residual parameter of the hot secondary air component include:

[0043] Determine the water supply temperature requirement level according to the water supply temperature requirement value, and determine the corresponding water supply temperature requirement range according to the water supply temperature requirement level;

[0044] Obtaining the extraction parameters of the first stage of the high-pressure heating component, determining the extraction temperature of the first stage of the high-pressure heating component according to the extraction parameters, and calculating the difference between the minimum value of the feed water temperature requirement range and the extraction temperature of the first stage of the high-pressure heating component;

[0045] The second steam flow adjustment value is determined according to the difference between the minimum value of the feed water temperature requirement range and the first stage extraction temperature of the high pressure heating component.

[0046] The beneficial effects of the present invention are:

[0047] By applying the above technical scheme, the present invention extracts high-temperature and high-pressure steam from the boiler under low load of the coal-fired unit, and after decompression and temperature reduction, first enters the hot secondary air heater to heat the hot secondary air, greatly increasing the temperature of the hot secondary air, and realizing low-load stable combustion; the steam coming out of the hot secondary air heater is divided into two parts. One part of the steam is used for industrial heating after decompression; the other part of the steam enters the No. 1 high-pressure heater to replace the first stage of steam extraction, greatly increasing the feed water temperature, and ensuring stable and economical operation under low load. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A schematic structural diagram of a flexible circulation quality improvement system proposed in an embodiment of the present invention is shown;

[0050] Figure 2The figure shows an overall flow chart of a control method of a flexible circulation quality upgrading system proposed in an embodiment of the present invention.

[0051] In the figure: 1. boiler; 2. main steam pipeline; 3. air preheater; 4. hot secondary air heater; 5. first hot secondary air supply pipeline; 6. second hot secondary air pipeline; 7. steam branch pipeline; 8. first stop valve; 9. first pressure reducing valve; 10. cooling pipeline; 11. second stop valve; 12. second pressure reducing valve; 13. first check valve; 14. desuperheater; 15. first branch pipeline; 16. third stop valve; 17. third pressure reducing valve; 18. second check valve; 19. fourth stop valve; 20. second branch pipeline; 21. No. 1 high-pressure heater; 22. third check valve; 23. fifth stop valve; 24. a section of steam extraction pipeline. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0054] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] The present application embodiment provides a flexible circulation quality improvement system, such as Figure 1As shown, it includes: a boiler, connected to the high-pressure cylinder of the steam turbine, used to transport main steam to the high-pressure cylinder of the steam turbine through the main steam pipe; a hot secondary air component, connected to the boiler, used to transport hot secondary air to the boiler; a steam extraction component, one end of which is connected to the main steam pipe and the other end is connected to the hot secondary air component, used to extract the main steam in the boiler to heat the hot secondary air; an industrial heating component, connected to the hot secondary air component, used to transport the steam in the hot secondary air component to the industrial heating steam inlet; a high-pressure heating component, connected to the hot secondary air component, used to transport the steam in the hot secondary air component to the No. 1 high-pressure heater, and the No. 1 high-pressure heater is connected to the boiler through a high-temperature water supply pipe.

[0056] In this embodiment, the main steam in the boiler is extracted by the steam extraction component, and the main steam is transported to the hot secondary air component after being cooled and reduced in pressure to increase the temperature of the hot secondary air. A part of the steam in the hot secondary air component is transported to industrial heating through the industrial heating component, and the other part of the steam is transported to the No. 1 high-pressure heater through the high-pressure heating component.

[0057] In some embodiments of the present application, the hot secondary air component includes: an air preheater; a hot secondary air heater, the air preheater is connected to the boiler via a first hot secondary air duct, and the hot secondary air heater is connected to the boiler via a second hot secondary air duct.

[0058] In some embodiments of the present application, the steam extraction component includes: a steam branch pipe, one end of which is connected to the main steam pipe, and the other end is connected to the hot secondary air heater, and the steam branch pipe is provided with a first stop valve and a first pressure reducing valve in sequence on the side close to the main steam pipe; a cooling pipe, connected to the side of the steam branch pipe away from the main steam pipe, and the cooling pipe is provided with a second stop valve, a second pressure reducing valve, a first check valve, and a cooler in sequence.

[0059] In this embodiment, the main steam extracted from the boiler is cooled and decompressed by a pressure reducing valve and a temperature reducing pipeline, and then transported to the hot secondary air heater.

[0060] In some embodiments of the present application, the industrial heating component includes: a first branch pipe, one end of which is connected to the hot secondary air heater, and the other end is connected to the industrial heating steam inlet, and the first branch pipe is sequentially provided with a third stop valve, a third pressure reducing valve, a second check valve, and a fourth stop valve.

[0061] In this embodiment, the extracted main steam heats the hot secondary air and then a portion of it is transported to the industrial heating steam inlet through the first branch pipeline, the third stop valve, the third pressure reducing valve, the second check valve, and the fourth stop valve for industrial heating.

[0062] In some embodiments of the present application, the high-pressure heating component includes: a second branch pipe, one end of which is connected to the hot secondary air heater, and the other end is connected to the No. 1 high-pressure heater, and the second branch pipe is provided with a third check valve and a fifth stop valve in sequence on the side away from the first branch pipe; a section of steam extraction pipe, which is connected to the second branch pipe.

[0063] In this embodiment, another part of the main steam in the hot secondary air heater enters the No. 1 high-pressure heater through the third check valve and the fifth stop valve, which can replace a stage of steam extraction and further increase the feed water temperature.

[0064] Based on the same technical concept, such as Figure 2 As shown, the present invention also provides a control method for a flexible circulation quality improvement system, comprising:

[0065] S101, obtaining a current unit load change value, determining a hot secondary air target temperature according to the current unit load change value, and setting a main steam adjustment value of a steam extraction component according to the hot secondary air target temperature;

[0066] In some embodiments of the present application, determining the target temperature of hot secondary air according to the target load value of the unit includes: obtaining the boiler temperature value, and drawing a current boiler temperature change curve according to the change of the boiler temperature value with the random unit load; obtaining the historical unit load change value and the corresponding boiler temperature change curve, and establishing a training set and a test set according to the historical unit load change value and the corresponding boiler temperature change curve; establishing an initial boiler temperature prediction model, and training the initial boiler temperature prediction model according to the training set and the test set to obtain a trained boiler temperature prediction model; inputting the current unit load change value into the trained boiler temperature prediction model to obtain a boiler temperature standard change curve; obtaining the correlation between the current boiler temperature change curve and the boiler temperature standard change curve, calculating the ratio of the correlation between the current boiler temperature change curve and the boiler temperature standard change curve to the preset standard correlation, and obtaining a hot secondary air target temperature correction coefficient; multiplying the hot secondary air target temperature correction coefficient by the preset standard hot secondary air target temperature to obtain the hot secondary air target temperature.

[0067] In this embodiment, a boiler temperature prediction model is trained based on historical unit load change values ​​and corresponding boiler temperature change curves, so that a standard boiler temperature change curve is predicted according to the current unit load change value. The preset standard hot secondary air target temperature is corrected by the ratio of the correlation between the current boiler temperature change curve and the standard boiler temperature change curve to the preset standard correlation, so that the temperature of the hot secondary air can meet the load requirements.

[0068] In some embodiments of the present application, the method of setting the main steam adjustment value of the steam extraction component according to the hot secondary air target temperature includes: obtaining the hot secondary air temperature of the current hot secondary air component, calculating the difference between the hot secondary air target temperature and the current hot secondary air temperature, and judging whether the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a first preset threshold value; if the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than the first preset threshold value, setting the first adjustment parameter as the main steam adjustment value of the steam extraction component; if the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the first preset threshold value, judging whether the difference between the predicted electricity price and the preset electricity price allowable value is greater than the second preset threshold value; if the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than the second preset threshold value, setting the second adjustment parameter as the main steam adjustment value of the steam extraction component; if the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the second preset threshold value, setting the third adjustment parameter as the main steam adjustment value of the steam extraction component.

[0069] In this embodiment, the main steam regulation value is specifically the pressure regulation value and temperature regulation value of the main steam. The main steam regulation value of the steam extraction component is set by the difference between the hot secondary air target temperature and the current hot secondary air temperature, so that the main steam is cooled and reduced in pressure to the target value.

[0070] S102, obtaining an industrial heating demand value, and setting a first steam flow adjustment value of the industrial heating component according to the industrial heating demand value;

[0071] In some embodiments of the present application, the first steam flow adjustment value of the industrial heating component is set according to the industrial heating demand value, including: determining the industrial heating demand level according to the industrial heating demand value, and determining the corresponding industrial heating demand range according to the industrial heating demand level; determining the industrial heating temperature demand range according to the industrial heating demand range, obtaining the steam temperature value entering the industrial heating component, and calculating the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range; determining the first steam flow adjustment value according to the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range.

[0072] In this embodiment, the industrial heating demand value is obtained from the heating side, and the industrial heating demand level is determined according to the industrial heating demand value. Each industrial heating demand level is corresponding to an industrial heating demand range. The industrial heating temperature demand range in the industrial heating demand range is extracted, and the main steam flow is adjusted by calculating the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range. The larger the difference, the lower the corresponding main steam flow.

[0073] S103, obtaining the main steam residual parameter of the hot secondary air component, and setting the second steam flow adjustment value of the high-pressure heating component according to the main steam residual parameter of the hot secondary air component.

[0074] In some embodiments of the present application, the method of obtaining the main steam residual parameters of the hot secondary air component and setting the second steam flow adjustment value of the high-pressure heating component according to the main steam residual parameters of the hot secondary air component includes: determining the feed water temperature requirement level according to the feed water temperature requirement value, and determining the corresponding feed water temperature requirement range according to the feed water temperature requirement level; obtaining a first-stage steam extraction parameter of the high-pressure heating component, determining a first-stage steam extraction temperature of the high-pressure heating component according to the first-stage steam extraction parameter, and calculating the difference between the minimum value of the feed water temperature requirement range and the first-stage steam extraction temperature of the high-pressure heating component; and determining the second steam flow adjustment value according to the difference between the minimum value of the feed water temperature requirement range and the first-stage steam extraction temperature of the high-pressure heating component.

[0075] In this embodiment, the feed water temperature demand value is obtained by the current feed water temperature, and the feed water temperature demand level is determined by the feed water temperature demand value. Each feed water temperature demand level is correspondingly provided with a feed water temperature demand range. The main steam flow entering the high-pressure heating component is adjusted by calculating the difference between the minimum value of the feed water temperature demand range and the first extraction temperature of the high-pressure heating component. The larger the difference, the higher the corresponding main steam flow.

[0076] By applying the flexible circulation quality improvement system of the present application, it includes a boiler connected to the high-pressure cylinder of the steam turbine, used to transport the main steam to the high-pressure cylinder of the steam turbine through the main steam pipeline; a hot secondary air component connected to the boiler, used to transport the hot secondary air to the boiler; a steam extraction component, one end of which is connected to the main steam pipeline and the other end is connected to the hot secondary air component, used to extract the main steam in the boiler to heat the hot secondary air; an industrial heating component connected to the hot secondary air component, used to transport the steam in the hot secondary air component to the industrial heating steam inlet; a high-pressure heating component, connected to the hot secondary air component, used to transport the steam in the hot secondary air component to the No. 1 high-pressure heater, and the No. 1 high-pressure heater is connected to the boiler through a high-temperature water supply pipe. Improve the low-load stable combustion effect of the unit and ensure stable and economical operation of the unit.

[0077] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present invention.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements 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 the present application.

Claims

1. A flexible circulation quality improvement system, characterized in that: include: A boiler connected to the high-pressure cylinder of the steam turbine and used for conveying main steam to the high-pressure cylinder of the steam turbine through a main steam pipeline; a hot secondary air component, connected to the boiler, for conveying hot secondary air to the boiler; A steam extraction component, one end of which is connected to the main steam pipeline and the other end of which is connected to the hot secondary air component, and is used to extract the main steam in the boiler to heat the hot secondary air; An industrial heating component, connected to the hot secondary air component, for conveying the steam in the hot secondary air component to the industrial heating steam inlet; The high-pressure heating component is connected to the hot secondary air component and is used to transport the steam in the hot secondary air component to the No. 1 high-pressure heater. The No. 1 high-pressure heater is connected to the boiler through a high-temperature water supply pipe.

2. The flexible circulation upgrading system according to claim 1 is characterized in that: The hot secondary air component comprises: Air preheater; The hot secondary air heater is connected to the air preheater via a first hot secondary air duct, and the hot secondary air heater is connected to the boiler via a second hot secondary air duct.

3. The flexible circulation upgrading system according to claim 2 is characterized in that: The steam extraction assembly comprises: A steam branch pipe, one end of which is connected to the main steam pipe, and the other end of which is connected to the hot secondary air heater, wherein a first stop valve and a first pressure reducing valve are sequentially arranged on the side of the steam branch pipe close to the main steam pipe; The temperature reduction pipeline is connected to the side of the steam branch pipeline away from the main steam pipeline. The temperature reduction pipeline is sequentially provided with a second stop valve, a second pressure reducing valve, a first check valve, and a temperature reducer.

4. The flexible circulation upgrading system according to claim 3 is characterized in that: The industrial heating assembly comprises: The first branch pipeline has one end connected to the hot secondary air heater and the other end connected to the industrial heating steam inlet. The first branch pipeline is sequentially provided with a third stop valve, a third pressure reducing valve, a second check valve, and a fourth stop valve.

5. The flexible circulation upgrading system according to claim 4 is characterized in that: The high-pressure heating component comprises: A second branch pipeline, one end of which is connected to the hot secondary air heater, and the other end of which is connected to the No. 1 high-pressure heater, and a third check valve and a fifth stop valve are sequentially arranged on the side of the second branch pipeline away from the first branch pipeline; A section of steam extraction pipeline is connected to the second branch pipeline.

6. A control method for a flexible circulation upgrading system according to any one of claims 1 to 5, characterized in that: include: Obtain the current unit load change value, determine the hot secondary air target temperature according to the current unit load change value, and set the main steam adjustment value of the steam extraction component according to the hot secondary air target temperature; Obtaining an industrial heating demand value, and setting a first steam flow adjustment value of the industrial heating component according to the industrial heating demand value; Obtain the main steam residual parameters of the hot secondary air component, and set the second steam flow adjustment value of the high-pressure heating component according to the main steam residual parameters of the hot secondary air component.

7. The control method of the flexible circulation upgrading system according to claim 6 is characterized in that: Determining the target temperature of hot secondary air according to the target load value of the unit includes: Get the boiler temperature value, and draw the current boiler temperature change curve according to the change of boiler temperature value and random group load; Obtain historical unit load change values ​​and corresponding boiler temperature change curves, and establish training sets and test sets based on the historical unit load change values ​​and corresponding boiler temperature change curves; An initial boiler temperature prediction model is established, and the initial boiler temperature prediction model is trained according to a training set and a test set to obtain a trained boiler temperature prediction model; Input the current unit load change value into the trained boiler temperature prediction model to obtain the boiler temperature standard change curve; Obtaining the correlation between the current boiler temperature change curve and the boiler temperature standard change curve, calculating the ratio of the correlation between the current boiler temperature change curve and the boiler temperature standard change curve to the preset standard correlation, and obtaining the hot secondary air target temperature correction coefficient; The hot secondary air target temperature correction coefficient is multiplied by the preset standard hot secondary air target temperature to obtain the hot secondary air target temperature.

8. The control method of the flexible circulation upgrading system according to claim 7 is characterized in that: The method of setting the main steam adjustment value of the steam extraction component according to the hot secondary air target temperature includes: Obtaining the hot secondary air temperature of the current hot secondary air component, calculating the difference between the hot secondary air target temperature and the current hot secondary air temperature, and determining whether the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a first preset threshold; If the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a first preset threshold, setting the first adjustment parameter as the main steam adjustment value of the steam extraction component; If the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the first preset threshold, determining whether the difference between the predicted electricity price and the preset electricity price allowable value is greater than the second preset threshold; If the difference between the hot secondary air target temperature and the current hot secondary air temperature is greater than a second preset threshold, setting the second adjustment parameter as the main steam adjustment value of the steam extraction component; If the difference between the hot secondary air target temperature and the current hot secondary air temperature is less than or equal to the second preset threshold, the third adjustment parameter is set as the main steam adjustment value of the steam extraction component.

9. The control method of the flexible circulation upgrading system according to claim 8, characterized in that: The step of setting the first steam flow adjustment value of the industrial heating component according to the industrial heating demand value comprises: Determine the industrial heating demand level according to the industrial heating demand value, and determine the corresponding industrial heating demand range according to the industrial heating demand level; Determine the industrial heating temperature demand range according to the industrial heating demand range, obtain the steam temperature value entering the industrial heating component, and calculate the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range; The first steam flow adjustment value is determined according to the difference between the steam temperature value entering the industrial heating component and the maximum value of the industrial heating temperature demand range.

10. The control method of the flexible circulation upgrading system according to claim 9, characterized in that: The method of obtaining the remaining parameters of the main steam of the hot secondary air component and setting the second steam flow adjustment value of the high-pressure heating component according to the remaining parameters of the main steam of the hot secondary air component includes: Determine the water supply temperature requirement level according to the water supply temperature requirement value, and determine the corresponding water supply temperature requirement range according to the water supply temperature requirement level; Obtaining the extraction parameters of the first stage of the high-pressure heating component, determining the extraction temperature of the first stage of the high-pressure heating component according to the extraction parameters, and calculating the difference between the minimum value of the feed water temperature requirement range and the extraction temperature of the first stage of the high-pressure heating component; The second steam flow adjustment value is determined according to the difference between the minimum value of the feed water temperature demand range and the first stage extraction temperature of the high pressure heating component.

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