A kind of air supply control system and method based on large flow heating unit

Abstract

The present invention discloses a method and system for air supply control of a large-flow heating unit. The method includes: S1, obtaining instructions and parameters related to the boiler air supply volume command Y and the actual boiler air supply volume T, and obtaining relevant formulas through experiments; S2, setting alarm parameters and alarm types related to the actual boiler air supply volume command; S3, using Y as the set value of the boiler air supply volume control PID, T as the measured value, and the active power of the generator as the feedforward value, and adopting the PID control algorithm in the DCS system for control, where K p is the proportional coefficient of the boiler air supply volume control PID, and K i is the integral coefficient; S4, setting the manual-automatic switching condition and sending a switching alarm when it is reached; S5, using the measured value of the generator power as the feedforward signal of the PID to conduct a disturbance test, and fine-tuning the generator power in combination with the formula; S6, conducting disturbance tests under multiple heat supply changes to fine-tune the relevant coefficients and parameters of the formula. Precise and rapid control of the boiler air supply volume.

Description

Technical Field

[0001] The invention relates to the technical field of power station rotating equipment control systems, and in particular to an air supply control system and method based on a large-flow heating unit. Background Art

[0002] In power plants, as the utilization hours decrease year by year, the economic efficiency of thermal power generation units is declining. In order to increase the utilization hours of generator sets and improve the utilization rate of units, many power plants have carried out heating technology transformation. By supplying heat to external units, the utilization rate of units is improved and the economic efficiency of unit power generation is improved. However, after the heating transformation, the characteristics of the generator sets have changed. The original design of the air supply automatic control system cannot meet the precise control under large heating conditions, and even the control system may diverge and oscillate, resulting in a decrease in the level of automatic control of the unit, reducing the economic efficiency of unit operation, and even affecting the safety of unit operation.

[0003] The air supply control system and optimization under large heating flow conditions not only requires the stability of the control system, but also the speed and accuracy of the control system. In this case, it is necessary to design a boiler air supply control system based on large-flow heating conditions. While fully considering the impact of changes in heating volume, the new system can adapt to this impact, which can improve the accuracy of the unit's air supply control and make the boiler combustion more stable and economical, which is particularly urgent to be solved. Summary of the invention

[0004] The purpose of the present invention is to provide an air supply control system and method based on a large-flow heating unit, which can realize accurate and rapid control of the boiler air supply volume when the generator set is supplying heat with large flow, thereby ensuring the safe, economical and rapid operation of the generator set.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides an air supply control method based on a large flow heating unit, comprising:

[0006] S1, obtaining instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and obtaining formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments;

[0007] S2, setting alarm parameters and alarm types related to the actual air supply volume instruction of the boiler;

[0008] S3, the boiler air volume instruction Y is used as the set value of the boiler air volume control PID, the actual boiler air volume T is used as the measured value of the boiler air volume control PID, and the generator active power is used as the feedforward value of the boiler air volume control PID, and the PID control algorithm in the DCS system is used for control, wherein K p is the proportional coefficient of the boiler air flow control PID, Ki The integral coefficient of the boiler air supply control PID;

[0009] S4, setting the manual-automatic switching condition of the control device corresponding to the boiler air supply volume control PID, and issuing a switching alarm when the manual-automatic switching condition is reached;

[0010] S5, using the generator power measurement value as the PID feedforward signal, performing multiple disturbance tests on the new boiler air supply control device under the condition of generator power changes, and fine-tuning the generator power according to the control effect and the formula before achieving the expected control effect;

[0011] S6, performing multiple disturbance tests on the new boiler air supply control device under changes in heating amount, and fine-tuning the correlation coefficient and parameters of the formula according to the air supply control effect before achieving the expected air supply control effect.

[0012] Wherein, the S1 includes:

[0013] Obtaining instructions related to the boiler air supply volume instruction, including:

[0014] Obtain the generator load instruction X1, the heating flow instruction X2, and the boiler flue gas oxygen content setting value X3;

[0015] And the formula related to the boiler air supply volume instruction is obtained through experiments, including:

[0016] The boiler air supply volume instruction Y: Y=Y1+Y2+Y3;

[0017] The relationship between the generator set load command X1 and Y1 is:

[0018]

[0019] The relationship between the heating flow X2 instruction and Y2 is:

[0020]

[0021] The relationship between the boiler flue gas oxygen content setting value X3 and Y3 is:

[0022]

[0023] Wherein, the S1 includes:

[0024] The instructions related to the actual air supply volume of the boiler include:

[0025] The secondary air volume U1 is filtered to obtain T1, the primary air volume U2 is filtered to obtain T2, the actual heat supply W is filtered to obtain U3, and U3 is converted and corrected to obtain T3;

[0026] The formulas related to the actual air supply volume of the boiler obtained through the experiment include:

[0027] The actual air supply volume T of the boiler: T = T1 + T2 + T3;

[0028] The boiler secondary air volume measurement value U1 is filtered to obtain T1;

[0029] T1=(1-e -t / 5 )*U1 (4),

[0030] The boiler primary air volume U2 is obtained after filtering T2;

[0031] T2=(1-e -t / 5 )*U2 (5),

[0032] The actual heat supply W is filtered to obtain U3, which is converted to T3 after correction;

[0033] U3=(1-e -t / 3 )*W (6),

[0034]

[0035] Wherein, the S2 includes:

[0036] When the change rate of the secondary air volume U1 is greater than 100, a first change rate exceeding limit signal is issued;

[0037] When the change rate of the primary air volume U2 is greater than 50, a second change rate exceeding limit signal is issued;

[0038] When the change rate of the actual heating amount W is greater than 10, a third change rate exceeding limit signal is issued.

[0039] Wherein, the S4 includes:

[0040] When the deviation between the air volume of at least one of the first change rate over-limit signal, the second change rate over-limit signal, the second change rate over-limit signal, and Y and the actual air volume T of the boiler is greater than 200 tons / hour, a deviation over-limit alarm signal is issued, and the boiler air volume control device is switched from automatic operation to manual operation, and an air volume control device switch to manual alarm is issued.

[0041] Wherein, the S3 includes:

[0042] Configure the PID parameters of the boiler air volume control device and perform parameter tuning to achieve variable parameter automatic control, K p , K i It is a parameter that automatically matches the size of the active power generated by the generator set. Its functional relationship is as follows:

[0043] K p =10 -6 Y 2 -0.002Y+3.0001 (8),

[0044] K i =-5*10 -7 Y 2 +0.0009Y+0.5062 (9).

[0045] Wherein, after S6:

[0046] S7, after the new boiler air supply control device is put into trial operation for a period longer than expected, the correlation coefficient and parameters of the formula are optimized according to the regulation divergence and parameter oscillation that occur, and the device is officially put into production operation.

[0047] In addition, the embodiment of the present application further provides an air supply control system based on a large flow heating unit, including:

[0048] A parameter acquisition and formula generation module, used to acquire instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and to obtain formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments;

[0049] A boiler actual air supply volume alarm setting module, used to set alarm parameters and alarm types related to the boiler actual air supply volume instruction;

[0050] The PID control module is used to use the boiler air volume instruction Y as the set value of the boiler air volume control PID, the actual boiler air volume T as the measured value of the boiler air volume control PID, and the generator active power as the feedforward value of the boiler air volume control PID, and adopt the PID control algorithm in the DCS system for control, wherein K p is the proportional coefficient of the boiler air flow control PID, K i The integral coefficient of the boiler air supply control PID;

[0051] A manual-automatic switching module, used to set the manual-automatic switching conditions of the control device corresponding to the boiler air supply volume control PID, and to issue a switching alarm when the manual-automatic switching conditions are met;

[0052] A generator power fine-tuning module is used to use the generator power measurement value as the feedforward signal of the PID, to conduct multiple disturbance tests under the generator power change on the new boiler air supply control device, and to fine-tune the generator power according to the control effect combined with the formula before achieving the expected control effect;

[0053] The formula parameter fine-tuning module is used to perform multiple disturbance tests on the new boiler air supply control device under changes in heating amount, and to fine-tune the correlation coefficients and parameters of the formula according to the air supply control effect before achieving the expected air supply control effect.

[0054] Among them, it also includes a tuning module connected to the formula parameter fine-tuning module, which is used to tune the correlation coefficients and parameters of the formula according to the adjustment divergence and parameter oscillation that occur after the new boiler air supply control device is put into trial operation for longer than expected, and then officially put it into production operation.

[0055] The air supply control method and system based on a large flow heating unit provided in the embodiment of the present invention have the following advantages compared with the prior art:

[0056] The air supply control method and system based on a large-flow heating unit provided in the embodiment of the present invention utilize an experimental method to construct the input of the air supply control system, including the boiler air supply volume instruction and the actual boiler air supply volume. At the same time, the generator active power signal is introduced as the feedforward signal of the boiler air supply control system PID, and a variable parameter adjustment strategy is adopted. Therefore, when the generator set is providing heat with a large flow rate, accurate and rapid control of the boiler air supply volume can be achieved, thereby ensuring the safe, economical and rapid operation of the generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A schematic diagram of the steps of a specific implementation method of the air supply control method for a large flow heating unit provided in an embodiment of the present invention;

[0059] Figure 2 A schematic diagram of the steps of another specific implementation method of the air supply control method for a large flow heating unit provided in an embodiment of the present invention;

[0060] Figure 3 A structural schematic diagram of a specific implementation of an air supply control system based on a large-flow heating unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] Please refer to Figure 1-3 , Figure 1 A schematic diagram of the steps of a specific implementation method of the air supply control method for a large flow heating unit provided in an embodiment of the present invention; Figure 2 A schematic diagram of the steps of another specific implementation method of the air supply control method for a large flow heating unit provided in an embodiment of the present invention; Figure 3 A structural schematic diagram of a specific implementation of an air supply control system based on a large-flow heating unit provided in an embodiment of the present invention.

[0063] In a specific implementation, the air supply control method based on a large flow heating unit includes:

[0064] S1, obtaining instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and obtaining formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments;

[0065] S2, setting alarm parameters and alarm types related to the actual air supply volume instruction of the boiler;

[0066] S3, the boiler air volume instruction Y is used as the set value of the boiler air volume control PID, the actual boiler air volume T is used as the measured value of the boiler air volume control PID, and the generator active power is used as the feedforward value of the boiler air volume control PID, and the PID control algorithm in the DCS system is used for control, wherein K p is the proportional coefficient of the boiler air flow control PID, K i The integral coefficient of the boiler air supply control PID;

[0067] S4, setting the manual-automatic switching condition of the control device corresponding to the boiler air supply volume control PID, and issuing a switching alarm when the manual-automatic switching condition is reached;

[0068] S5, using the generator power measurement value as the PID feedforward signal, performing multiple disturbance tests on the new boiler air supply control device under the condition of generator power changes, and fine-tuning the generator power according to the control effect and the formula before achieving the expected control effect;

[0069] S6, performing multiple disturbance tests on the new boiler air supply control device under changes in heating amount, and fine-tuning the correlation coefficient and parameters of the formula according to the air supply control effect before achieving the expected air supply control effect.

[0070] Using the experimental method, the input of the air supply control system is constructed, including the boiler air supply volume instruction and the actual boiler air supply volume. At the same time, the generator active power signal is introduced as the feedforward signal of the boiler air supply control system PID, and a variable parameter adjustment strategy is adopted. It can achieve accurate and rapid control of the boiler air supply volume when the generator set is supplying heat with a large flow rate, thereby ensuring the safe, economical and rapid operation of the generator set.

[0071] The present application does not limit the type of instructions related to the boiler air supply volume instructions that need to be obtained and the method of obtaining them. It can be obtained through a preset method or by selecting from multiple preset groups of instructions.

[0072] In one embodiment, the S1 comprises:

[0073] Obtaining instructions related to the boiler air supply volume instruction, including:

[0074] Obtain the generator load instruction X1, the heating flow instruction X2, and the boiler flue gas oxygen content setting value X3;

[0075] And the formula related to the boiler air supply volume instruction is obtained through experiments, including:

[0076] The boiler air supply volume instruction Y: Y=Y1+Y2+Y3;

[0077] The relationship between the generator set load command X1 and Y1 is:

[0078]

[0079] The relationship between the heating flow X2 instruction and Y2 is:

[0080]

[0081] The relationship between the boiler flue gas oxygen content setting value X3 and Y3 is:

[0082]

[0083] It should be pointed out that the above instruction types can be selected as needed, and can even be increased. The above formula is not necessarily obtained in a fixed way, and can be obtained by fitting methods such as linear fitting and least squares fitting.

[0084] Similarly, there is no limitation on the instruction type and formula fitting method related to the actual air supply volume of the boiler. In one embodiment, S1 includes:

[0085] The instructions related to the actual air supply volume of the boiler include:

[0086] The secondary air volume U1 is filtered to obtain T1, the primary air volume U2 is filtered to obtain T2, the actual heat supply W is filtered to obtain U3, and U3 is converted and corrected to obtain T3;

[0087] The formulas related to the actual air supply volume of the boiler obtained through the experiment include:

[0088] The actual air supply volume T of the boiler: T = T1 + T2 + T3;

[0089] The boiler secondary air volume measurement value U1 is filtered to obtain T1;

[0090] T1=(1-e -t / 5 )*U1 (4),

[0091] The boiler primary air volume U2 is obtained after filtering T2;

[0092] T2=(1-e -t / 5 )*U2 (5),

[0093] The actual heat supply W is filtered to obtain U3, which is converted to T3 after correction;

[0094] U3=(1-e -t / 3 )*W (6),

[0095] T3=-0.0004U3 2 +0.5672U3+2.7688 (7).

[0096] In order to improve the monitoring efficiency, logical errors may occur in the acquired data. In one embodiment, S2 includes:

[0097] When the change rate of the secondary air volume U1 is greater than 100, a first change rate exceeding limit signal is issued;

[0098] When the change rate of the primary air volume U2 is greater than 50, a second change rate exceeding limit signal is issued;

[0099] When the change rate of the actual heating amount W is greater than 10, a third change rate exceeding limit signal is issued.

[0100] It should be noted that the present application includes but is not limited to the above-mentioned threshold for issuing an over-limit signal, which can be set by the worker as needed, and the number of situations in which an over-limit signal is issued can be appropriately increased or decreased.

[0101] Since the control is mainly carried out through automatic adjustment in the present application, if the measured value is abnormal, it may cause a safety accident, and manual adjustment is required at this time, so it is necessary to switch between automatic and manual adjustment. Therefore, in one embodiment, in order to increase the evolution speed of the system, in one embodiment, S4 includes:

[0102] When the deviation between the air volume of at least one of the first change rate over-limit signal, the second change rate over-limit signal, the second change rate over-limit signal, and Y and the actual air volume T of the boiler is greater than 200 tons / hour, a deviation over-limit alarm signal is issued, and the boiler air volume control device is switched from automatic operation to manual operation, and an air volume control device switch to manual alarm is issued.

[0103] It should be pointed out that the deviation threshold from the actual air supply volume T of the boiler is not necessarily 200 tons / hour, but can also be set according to the actual scale of the power station, etc., and the conditions for switching from automatic operation to manual operation are not necessarily limited to the above four. The staff can increase them appropriately as needed, or select other possible options from the preset possibilities.

[0104] In this application, PID is required for adjustment, and the parameters are not limited. In one embodiment, S3 includes:

[0105] Configure the PID parameters of the boiler air volume control device and perform parameter tuning to achieve variable parameter automatic control, K p , K i It is a parameter that automatically matches the size of the active power generated by the generator set. Its functional relationship is as follows:

[0106] K p =10 -6 Y 2 -0.002Y+3.0001 (8),

[0107] K i =-5*10 -7 Y 2 +0.0009Y+0.5062 (9).

[0108] After completing the initial formula and parameter setting, after running for a certain period of time, the actual operating parameters are obtained. At this time, the previous parameter settings may become unreasonable or suboptimal, so they need to be adjusted and optimized. Therefore, after S6:

[0109] S7, after the new boiler air supply control device is put into trial operation for a period longer than expected, the correlation coefficient and parameters of the formula are optimized according to the regulation divergence and parameter oscillation that occur, and the device is officially put into production operation.

[0110] The implementation method of this application adopts the method of "field test, parameter fitting, construction of boiler air supply volume instructions, construction of actual boiler air supply volume, disturbance test, and on-site implementation", which integrates the "over-limit alarm" of the large heating flow unit air supply control system and has good stability and speed.

[0111] It also has the functions of abnormal identification and automatic switching to manual operation. When the measured value is abnormal, the change rate exceeds the limit alarm, the measured value and the instruction deviation exceeds the limit, etc., an alarm will be issued, and the boiler air supply control system will be changed from "automatic" to "manual" to ensure that the control system switches to a safe state in the event of an abnormality, preventing large fluctuations in boiler air volume control due to control system failure, affecting the stability of boiler combustion, and even causing boiler combustion extinguishing accidents. While ensuring the safe and reliable operation of the generator set, it also ensures the rapid and economical operation of the boiler air supply control system.

[0112] In one embodiment, the air supply control method based on a large flow heating unit is as follows:

[0113] Step 1: Sort out the relevant measuring points of the system, find out the relationship between the measuring points, fit the relationship through the test data, and construct the parameters to be used, such as boiler air supply instructions, actual boiler air supply volume, etc.;

[0114] Step 2: Select the PID algorithm commonly used in DCS system;

[0115] Step 3: PID parameters are adjusted, and variable parameters Kp and Ki are used to adjust the strategy;

[0116] Step 4: Select the PID control feedforward signal and use the generator power measurement value as the PID feedforward signal. When the generator power increases or decreases, the boiler air supply volume can be quickly and effectively matched;

[0117] Step 5: Conduct a disturbance test on the new boiler air supply control system under the condition of generator power change (increase 100MW, decrease 100MW). Through multiple disturbance tests, observe the effect of the boiler air supply control system and make fine adjustments to formula (4), formula (5), formula (8) and formula (9).

[0118] Step 6: Conduct disturbance tests on the new boiler air supply control system under changes in heat supply (increase 100T / H, decrease 100T / H). Through multiple disturbance tests, observe the effect of the boiler air supply control system and fine-tune formulas (6), (7), (8), and (9).

[0119] Step 7: The control system is put into trial operation, generally for 7 to 10 days, to observe the performance of the new control system. If the new control system shows regulation divergence or parameter oscillation, a round of tuning is required for the new control system. The tuning includes: adjustment of the correlation coefficients and parameters of formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), and formula (7).

[0120] Step 8: After the above optimization, the model is officially put into production.

[0121] Step 9: Realize automatic control of boiler air supply under high-flow heating conditions. At the same time, when abnormal parameter changes are found, issue an alarm in time to remind production personnel to check and handle.

[0122] In addition, the embodiment of the present application further provides an air supply control system based on a large flow heating unit, including:

[0123] The parameter acquisition and formula generation module 10 is used to acquire instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and obtain formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments;

[0124] A boiler actual air supply volume alarm setting module 20, used to set alarm parameters and alarm types related to the boiler actual air supply volume instruction;

[0125] The PID control module 30 is used to use the boiler air volume instruction Y as the set value of the boiler air volume control PID, the actual boiler air volume T as the measured value of the boiler air volume control PID, and the generator active power as the feedforward value of the boiler air volume control PID, and adopt the PID control algorithm in the DCS system for control, wherein K p is the proportional coefficient of the boiler air flow control PID, K i The integral coefficient of the boiler air supply control PID;

[0126] A manual-automatic switching module 40 is used to set the manual-automatic switching conditions of the control device corresponding to the boiler air supply volume control PID, and to issue a switching alarm when the manual-automatic switching conditions are met;

[0127] The generator power fine-tuning module 50 is used to use the generator power measurement value as the feedforward signal of the PID, to perform multiple disturbance tests under the generator power change on the new boiler air supply control device, and to fine-tune the generator power according to the control effect combined with the formula before achieving the expected control effect;

[0128] The formula parameter fine-tuning module 60 is used to perform multiple disturbance tests on the new boiler air supply control device under changes in heating amount, and to fine-tune the correlation coefficients and parameters of the formula according to the air supply control effect before achieving the expected air supply control effect.

[0129] Since the air supply control system based on a large-flow heating unit is the system based on the above-mentioned air supply control method based on a large-flow heating unit, and has the same beneficial effects, this application will not repeat them again.

[0130] Since better operating parameters can be obtained in actual operation, and the parameters set before operation and the resulting formulas or parameters in the formulas have poor reliability or downside, in one embodiment, the air supply control system based on a large-flow heating unit also includes an optimization module connected to the formula parameter fine-tuning module, which is used to optimize the correlation coefficients and parameters of the formula according to the adjustment divergence and parameter oscillation that occur after the new boiler air supply control device is put into trial operation for longer than expected, and then formally put it into production operation.

[0131] By tuning the correlation coefficients and parameters of the formula, it can be operated in a more reasonable system, thereby improving operational reliability. It should be pointed out that the staff can also perform tuning again after continuing to run for a period of time, and this application does not limit this.

[0132] To summarize, the air supply control method and system based on a large-flow heating unit provided in the embodiment of the present invention utilizes an experimental method to construct the input of the air supply control system, including the boiler air supply volume instruction and the actual boiler air supply volume. At the same time, the generator active power signal is introduced as the feedforward signal of the boiler air supply control system PID, and a variable parameter adjustment strategy is adopted. This can achieve accurate and rapid control of the boiler air supply volume when the generator set is supplying heat with a large flow rate, thereby ensuring the safe, economical and rapid operation of the generator set.

[0133] The above is a detailed introduction to the air supply control method and system based on a large-flow heating unit provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for controlling air supply of a large flow heating unit, characterized in that: include: S1, obtaining instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and obtaining formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments; S2, setting alarm parameters and alarm types related to the actual air supply volume instruction of the boiler; S3, using the boiler air volume command Y as the set value of the boiler air volume control PID, the actual boiler air volume T as the measured value of the boiler air volume control PID, and the generator active power as the feedforward value of the boiler air volume control PID, and using the PID control algorithm in the DCS system for control, wherein K p is the proportional coefficient of the boiler air flow control PID, K i The integral coefficient of the boiler air supply control PID; S4, setting the manual-automatic switching condition of the control device corresponding to the boiler air supply volume control PID, and issuing a switching alarm when the manual-automatic switching condition is reached; S5, using the generator power measurement value as the PID feedforward signal, performing multiple disturbance tests on the new boiler air supply control device under the condition of generator power changes, and fine-tuning the generator power according to the control effect and the formula before achieving the expected control effect; S6, performing multiple disturbance tests on the new boiler air supply control device under changes in heat supply, and fine-tuning the correlation coefficient and parameters of the formula according to the air supply control effect before achieving the expected air supply control effect; The S1 includes: Obtaining instructions related to the boiler air supply volume instruction, including: Obtain the generator load instruction X1, the heating flow instruction X2, and the boiler flue gas oxygen content setting value X3; And the formula related to the boiler air supply volume instruction is obtained through experiments, including: The boiler air supply volume instruction Y: Y=Y1+Y2+Y3; The relationship between the generator set load command X1 and Y1 is: The relationship between the heating flow command X2 and Y2 is: The relationship between the boiler flue gas oxygen content setting value X3 and Y3 is: The S1 includes: The instructions related to the actual air supply volume of the boiler include: The secondary air volume U1 is filtered to obtain T1, the primary air volume U2 is filtered to obtain T2, the actual heat supply W is filtered to obtain U3, and U3 is converted and corrected to obtain T3; The formulas related to the actual air supply volume of the boiler obtained through the experiment include: The actual air supply volume T of the boiler: T = T1 + T2 + T3; The boiler secondary air volume U1 is filtered to obtain T1; T1=(1-e -t / 5 )*U1 (4), The boiler primary air volume U2 is obtained after filtering T2; T2=(1-e -t / 5 )*U2 (5), The actual heat supply W is filtered to obtain U3, which is converted to T3 after correction; U3=(1-e -t / 3 )*W (6), 2. The air supply control method based on a large flow heating unit according to claim 1, characterized in that: The S2 includes: When the change rate of the secondary air volume U1 is greater than 100, a first change rate exceeding limit signal is issued; When the change rate of the primary air volume U2 is greater than 50, a second change rate exceeding limit signal is issued; When the change rate of the actual heating amount W is greater than 10, a third change rate exceeding limit signal is issued.

3. The air supply control method based on a large flow heating unit according to claim 2 is characterized in that: The S4 includes: When the deviation between the air volume of at least one of the first change rate over-limit signal, the second change rate over-limit signal, the third change rate over-limit signal, and Y and the actual air volume T of the boiler is greater than 200 tons / hour, a deviation over-limit alarm signal is issued, and the boiler air volume control device is switched from automatic operation to manual operation, and an alarm is issued that the air volume control device switches to manual operation.

4. The air supply control method based on a large flow heating unit as claimed in claim 3 is characterized in that: The S3 includes: Configure the PID parameters of the boiler air volume control device and perform parameter tuning to achieve variable parameter automatic control, K p , K i It is a parameter that automatically matches the size of the active power generated by the generator set. Its functional relationship is as follows: K p =10 -6 Y 2 -0.002Y+3.0001(8), K i =-5*10 -7 Y 2 +0.0009Y+0.5062(9)。 5. The air supply control method based on a large flow heating unit according to claim 4, characterized in that: After said S6: S7, after the new boiler air supply control device is put into trial operation for a period longer than expected, the correlation coefficient and parameters of the formula are optimized according to the regulation divergence and parameter oscillation that occur, and the device is officially put into production operation.

6. An air supply control system based on a large flow heating unit, characterized in that: The air supply control method based on a large flow heating unit according to any one of claims 1 to 5 is adopted, comprising: A parameter acquisition and formula generation module, used to acquire instructions and parameters related to the boiler air supply volume instruction Y and the actual boiler air supply volume T, and to obtain formulas related to the boiler air supply volume instruction and the actual boiler air supply volume instruction through experiments; A boiler actual air supply volume alarm setting module, used to set alarm parameters and alarm types related to the boiler actual air supply volume instruction; The PID control module is used to use the boiler air volume instruction Y as the set value of the boiler air volume control PID, the actual boiler air volume T as the measured value of the boiler air volume control PID, and the generator active power as the feedforward value of the boiler air volume control PID, and adopt the PID control algorithm in the DCS system for control, wherein K p is the proportional coefficient of the boiler air flow control PID, K i The integral coefficient of the boiler air supply control PID; A manual-automatic switching module, used to set the manual-automatic switching conditions of the control device corresponding to the boiler air supply volume control PID, and to issue a switching alarm when the manual-automatic switching conditions are met; A generator power fine-tuning module is used to use the generator power measurement value as the feedforward signal of the PID, to conduct multiple disturbance tests under the generator power change on the new boiler air supply control device, and to fine-tune the generator power according to the control effect combined with the formula before achieving the expected control effect; A formula parameter fine-tuning module is used to perform multiple disturbance tests on the new boiler air supply control device under changes in heating amount, and to fine-tune the correlation coefficients and parameters of the formula according to the air supply control effect before the expected air supply control effect is achieved; and also includes an optimization module connected to the formula parameter fine-tuning module, which is used to optimize the correlation coefficients and parameters of the formula according to the adjustment divergence and parameter oscillation that occur after the new boiler air supply control device is put into trial operation for longer than expected, and then officially put it into production operation.

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