An industrial flue gas heating furnace system and its control method

Abstract

The present invention provides an industrial flue gas heating furnace system and a control method therefor. The industrial flue gas heating furnace system includes: a flue gas heating furnace, which is provided with a burner mechanism, and the flue gas heating furnace is respectively communicated with a smoke inlet pipe and a smoke outlet pipe for receiving the flue gas to be treated and discharging the flue gas after heating and purification; a combustion-supporting air pipeline mechanism, which is communicated with the flue gas heating furnace through the burner mechanism to supply combustion-supporting air to the flue gas heating furnace; a gas pipeline mechanism, which is communicated with the flue gas heating furnace through the burner mechanism to supply gas to the flue gas heating furnace; and a control mechanism, which is electrically connected to at least the burner mechanism, the combustion-supporting air pipeline mechanism, and the gas pipeline mechanism to respectively control the supply of combustion-supporting air by the combustion-supporting air pipeline mechanism, the supply of gas by the gas pipeline mechanism, and the operation of the burner mechanism. The industrial flue gas heating furnace system of the present invention can automatically adjust the supply amounts of the combustion-supporting air and the gas so that the flue gas output temperature meets the requirements, and the flue gas temperature rise is stable.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of industrial flue gas heating and purification, and particularly to an industrial flue gas heating furnace system and a control method thereof. Background Art

[0002] At present, with the enhancement of enterprises' awareness of energy conservation and environmental protection and the requirements of the national environmental protection department, most industrial enterprises are equipped with industrial flue gas purification equipment and waste heat recovery equipment.

[0003] Generally, the temperature of naturally generated industrial flue gas is relatively low. However, the flue gas purification equipment needs a relatively high temperature to achieve a good purification effect during the purification process of the flue gas. In addition, the heat transfer efficiency is not high when low-temperature flue gas is purified, and the energy-saving and efficiency-enhancing effect is not obvious. Therefore, before the industrial flue gas enters the purification equipment and the heat exchange equipment (i.e., the waste heat recovery equipment), an industrial flue gas heating furnace needs to be added to increase the temperature of the flue gas input to the purification equipment and the heat exchange equipment, so as to achieve the effects of purifying the flue gas and saving energy and enhancing efficiency.

[0004] Traditional industrial flue gas heating furnaces require operators to manually ignite and burn the furnace, and manually adjust the opening degrees of the combustion-supporting air valve and the gas valve by observing the flame. However, the calorific value and pressure of most industrial gases fluctuate greatly. It is difficult for operators to control the required fuels such as combustion-supporting air and gas well without a high technical level. Therefore, in the prior art, during the temperature-raising process before purifying or heat-exchanging industrial flue gas, there are problems such as high labor intensity, high requirements for the technical level of operators, and easy occurrence of low gas combustion efficiency, energy waste, and unstable flue gas temperature rise. Summary of the Invention

[0005] Embodiments of the present invention provide an industrial flue gas heating furnace system and a control method thereof, which can automatically adjust the supply amounts of combustion-supporting air and gas so that the output temperature of the flue gas meets the requirements, and at the same time can effectively improve the fuel combustion efficiency and utilization rate, and make the flue gas temperature rise stably.

[0006] To solve the above technical problems, embodiments of the present invention provide an industrial flue gas heating furnace system, including:

[0007] A flue gas heating furnace, on which a burner mechanism is provided, and the flue gas heating furnace is respectively communicated with a smoke inlet pipe and a smoke outlet pipe to receive the flue gas to be processed and discharge the flue gas after heating and purifying;

[0008] A combustion-supporting air pipeline mechanism, which is communicated with the flue gas heating furnace through the burner mechanism to supply combustion-supporting air to the flue gas heating furnace;

[0009] A gas pipeline mechanism, which is communicated with the flue gas heating furnace through the burner mechanism to supply gas to the flue gas heating furnace; and

[0010] A control mechanism, which is electrically connected to at least the burner mechanism, the combustion-supporting air pipeline mechanism, and the gas pipeline mechanism to respectively control the supply of combustion-supporting air by the combustion-supporting air pipeline mechanism, the supply of gas by the gas pipeline mechanism, and the operation of the burner mechanism.

[0011] Preferably, the burner mechanism at least includes a burner assembly, a flame monitor, a flame temperature detector, and a flue gas outlet temperature detector.

[0012] Preferably, the combustion-supporting air pipeline mechanism at least includes a combustion-supporting air pipeline and a combustion-supporting air pressure detector, a combustion-supporting air flow detector, and a combustion-supporting air electric control valve provided on the combustion-supporting air pipeline.

[0013] Preferably, the gas pipeline mechanism at least includes a gas pipeline and a gas pressure detector, a gas flow detector, a gas cut-off valve, and a gas flow electric control valve provided on the gas pipeline.

[0014] An embodiment of the present invention also provides a control method for an industrial flue gas heating furnace system, including:

[0015] Receiving the flue gas, combustion-supporting air, and gas to be processed from the flue gas inlet pipeline, the combustion-supporting air pipeline, and the gas pipeline respectively;

[0016] Starting the burner mechanism to ignite the flue gas heating furnace;

[0017] Real-time monitoring of the flame state in the flue gas heating furnace through a flame monitor;

[0018] When abnormal flameout occurs, cutting off the gas pipeline and sending an alarm;

[0019] If there is no flameout phenomenon, obtaining the actual flame temperature value FIpv(t) in real time through a flame temperature detector;

[0020] If the actual flame temperature value does not meet the preset value range, using the case-based reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) and the minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state through the optimal air-fuel ratio fuzzy controller;

[0021] Obtaining the actual gas flow value GFpv(t) through a gas flow detector;

[0022] Calculating the given value AFsp(t) of the combustion-supporting air flow through the actual gas flow value: AFsp(t)=A(t)*GFpv(t);

[0023] Obtaining the actual combustion-supporting air flow value AFpv(t) through a combustion-supporting air flow detector;

[0024] Adjust the combustion air flow based on the given value and the actual value of the combustion air flow, so that the actual value of the flame temperature after the combustion air and the gas are mixed and burned at the current flow rate meets the preset value range;

[0025] After the actual value of the flame temperature meets the preset value range, obtain the actual value FUpv(t) of the flue gas output temperature through the flue gas output temperature detector;

[0026] If the flue gas output temperature value does not match the target value, infer the control parameters of the PID controller in the control mechanism based on the actual value and the target value of the flue gas output temperature;

[0027] Use the calculated value du(t) obtained by the PID controller based on the control parameters as the additional given value of the gas flow;

[0028] Adjust the gas flow based on the additional given value of the gas flow, so that the actual temperature value of the flue gas generated under the current combustion state meets the target value.

[0029] Preferably, the case where the actual value of the flame temperature does not meet the preset value range is specifically:

[0030] Taking the flame temperature set value FIsp(t) as the target value and the output value FIpv(t) of the flame temperature detector as the actual value, calculate the flame temperature deviation E at the current sampling moment fi (KT s ):

[0031] E fi (KT s )=FIsp(KT s )-FIpv(KT s ) (1)

[0032] Among them, K is the current sampling times, T s is the sampling period, and transfer the value of E fi (KT s ) to the optimal air-fuel ratio fuzzy controller in the control mechanism, and determine whether the flame temperature deviation meets the preset value range by the optimal air-fuel ratio fuzzy controller.

[0033] Preferably, using the case-based reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) and the minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state through the optimal air-fuel ratio fuzzy controller includes:

[0034] Detect the actual value of the flame temperature FIpv(t) and the real-time air-fuel ratio A(t) in real time, store and record the data according to the sampling period Ts, and create a matrix database of [FIpv(KTs), A(KTs)].

[0035] According to the execution period Tc of the case inference engine, poll the matrix of [FIpv(KTs), A(KTs)]; take the temperature range from the maximum value FIpv(max) of FIpv(t) to FIpv(max) - 100 °C, and retrieve all the air-fuel ratios within this temperature range to form an array (a) in ascending order [A(xTs), A(yTs), …… A(iTs)]; group the elements in the array (a) with a numerical deviation less than the target range into several sub-arrays (b)(c)……(n); count the number of elements in the array (a) and each sub-array (b)(c)……(n); select the sub-arrays with the number of elements greater than 5% of the total number of elements in the array (a), and form a new array (A); use the smallest element value A(min) and the largest element value A(max) in the array (A) as the air-fuel ratio band limit values and pass them to the optimal air-fuel ratio fuzzy controller.

[0036] Calculate the rate of change of the flame temperature deviation Efir(KTs) at the current sampling moment according to the flame temperature deviation Efi(KTs) at the current sampling moment and the flame temperature deviation Efi(KTs - Ts) at the previous sampling moment:

[0037] Efir(KTs) = [Efi(KTs) - Efi(KTs - Ts)] / Ts (2)

[0038] When Efi(KTs) > 0 °C, if Efir(KTs) < -6 °C / s or Efir(KTs) > 0 °C / s, then output the current air-fuel ratio A(t1) as A(t):

[0039] A(t) = A(KTs) - Efir(KTs) / d (3)

[0040] If -0.3 °C / s < Efir(KTs) < 0 °C / s, then output the current air-fuel ratio A(t1) as A(t):

[0041] A(t) = A(KTs) + Efir(KTs) / d (4)

[0042] Otherwise, do not adjust the current air-fuel ratio A(t1).

[0043] When Efi(KTs) < -100 °C, if Efir(KTs) < 0 °C / s, output the current air-fuel ratio A(t1) obtained according to Equation (3); otherwise, do not adjust the current air-fuel ratio A(t1).

[0044] When -100°C ≤ Efi(KTs) ≤ 0°C: Calculate the air-fuel ratio A(t) according to the air-fuel ratio fuzzy equation:

[0045] A(t) = [-b ± √(b^2 - 4a(c - FIpv(KTs)))] / 2a (5)

[0046] where [b^2 - 4a(c - FIpv(KTs))] ≥ 0;

[0047] Obtain the air-fuel ratios A(t)1 and A(t)2. If A(min) ≤ A(t)1 ≤ A(max), and A(min) ≤ A(t)2 ≤ A(max), then output the current air-fuel ratio A(t):

[0048] A(t) = MIN[A(t)1), A(t)2] (6)

[0049] If A(min) ≤ A(t)1 ≤ A(max), and A(t)2 < A(min) or A(max) < A(t)2, then output the previous air-fuel ratio A(t):

[0050] A(t) = A(t)1 (7)

[0051] If A(min) ≤ A(t)2 ≤ A(max), and A(t)1 < A(min) or A(max) < A(t)1, then output the previous air-fuel ratio A(t):

[0052] A(t) = A(t)2 (8)

[0053] Otherwise, the current air-fuel ratio A(t) is not adjusted.

[0054] Among them, d in the above formulas (3) and (4) is a constant, and a, b, and c in formula (5) are constants.

[0055] Preferably, if the flue gas output temperature value does not match the target value, the control parameters of the PID controller in the control mechanism in the current state deduced based on the actual value and the target value of the flue gas output temperature include:

[0056] Taking the flue gas temperature set value FUsp(t) as the target value and the output value FUpv(t) of the flue gas temperature detector as the actual value, calculate the flue gas temperature deviation Efu(KTs) at the current sampling moment:

[0057] Efu(KTs) = FUsp(KTs) - FUpv(KTs) (9)

[0058] Calculate the rate of change of flue gas temperature deviation Efur(KTs) at the current sampling time based on the flue gas temperature deviation Efu(KTs) at the current sampling time and the flue gas temperature deviation Efu(KTs - Ts) at the previous sampling time:

[0059] Efur(KTs) = [Efu(KTs) - Efu(K Ts - Ts)] / Ts (10)

[0060] Perform multi-point correction on the flue gas temperature deviation, including dividing the flue gas temperature deviation value into 7 segments according to its absolute value, i.e., 0 ≤ |Efu(KTs)| < E1; E1 ≤ |Efu(KTs)| < E2; E2 ≤ |Efu(KTs)| < E3; E3 ≤ |Efu(KTs)| < E4; E4 ≤ |Efu(KTs)| < E5; E5 ≤ |Efu(KTs)| < E6; E6 ≤ |Efu(KTs)|;

[0061] Where, E1 - E6 are all constants, and 0 < E1 < E2 < E3 < E4 < E5 < E6;

[0062] When E5 ≤ |Efu(KTs)|, the planned target rate of change of flue gas temperature deviation Efursp(t):

[0063] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E5 - E6) / Ta (11)

[0064] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P6, I = I6, D = D6;

[0065] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P61, I = 0, D = D61; Where, Ta is the minimum tuning period of the controller parameters, and P6, P61, I6, D6, D61 are non-zero constants;

[0066] When E4 ≤ |Efu(KTs)| < E5, the planned target rate of change of flue gas temperature deviation Efursp(t):

[0067] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E4 - E5) / Ta (12)

[0068] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P5, I = I5, D = D5;

[0069] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P51, I = 0, D = D51; where P5, P51, I5, D5, D51 are non-zero constants;

[0070] When E3 ≤ |Efu(KTs)| < E4, the planned target flue gas temperature deviation change rate Efursp(t):

[0071] Efursp(t) = [Efu(KTs) / |Efu(KTs)|]*(E3 - E4) / (2Ta) (13)

[0072] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P4, I = I4, D = D4;

[0073] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P41, I = 0, D = D41; where P4, P41, I4, D4, D41 are non-zero constants;

[0074] When E2 ≤ |Efu(KTs)| < E3, the planned target flue gas temperature deviation change rate Efursp(t):

[0075] Efursp(t) = [Efu(KTs) / |Efu(KTs)|]*(E2 - E3) / (3Ta) (14)

[0076] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P3, I = I3, D = D3;

[0077] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P31, I = I31, D = D31; where P3, P31, I3, I31, D3, D31 are non-zero constants;

[0078] When E1 ≤ |Efu(KTs)| < E2, set the PID controller parameters for this stage as P = P2, I = I2, D = D2; where P2, I2, D2 are non-zero constants;

[0079] When |Efu(KTs)| < E1, set the PID controller parameters for this stage as P = P1, I = I1, D = D1; where P1, I1, D1 are non-zero constants.

[0080] Preferably, the calculated value U(t) obtained by the PID controller based on the control parameters as the additional given value of the gas flow rate includes:

[0081] When E2 < |E fu (KT s )|, the change rate E fur (KT s ) of the flue gas temperature deviation at the current sampling moment, and the planned target flue gas temperature deviation change rate E fur sp(KT s ) at the current sampling moment are used as the input values of the PID controller, and the following formula (15) is used as the additional given value du(t) of the gas flow controller:

[0082] du(t) = P * [e Er (KT s ) - e Er (KT s - T s )] + I * e Er (KT s ) + D * [e Er (KT s ) - 2e Er (KT s - T s ) + e Er (KT s - 2T s )] (15)

[0083] In formula (15), e Er (KT s ) = [E fur sp(KT s ) - E fur (KT s )] (16)

[0084] The P, I, and D values of the corresponding control stage where |E fu (KT s )| is located are taken as the PID controller parameters;

[0085] In formula (16), E fur sp(KT s ) takes the calculated values of formulas (11), (12), (13), and (14) of the corresponding control stage where |E fu (KT s )| is located;

[0086] When |E fu (KT s )| ≤ E2, the flue gas temperature deviation E fu (KT s) As the input of the PID controller, the additional set value du(t) of the gas flow controller is given by the following formula (17):

[0087] du(t) = P * [E fu (KT s ) - E fu (KT s -T s )] + I * E fu (KT s ) + D * [E fu (KT s ) - 2E fu (KT s -T s ) + E fu (KT s -2T s )] (17)

[0088] Among them, the PID controller parameters are taken as the P, I, and D values in the corresponding control stage where |E fu (KT s )| is located;

[0089] The output value U(t) of the PID controller is used as the additional set value of the gas flow, where:

[0090] U(t) = U + du(t) (18)

[0091] In formula (18), U is the initial set value of the gas flow, which is a constant, and du(t) is obtained from calculation formulas (15) and (17).

[0092] Based on the disclosure of the above embodiments, the beneficial effects of the embodiments of the present invention are that the industrial flue gas heating furnace system is fully automatically controlled with flameout interlock protection. Moreover, through the monitoring of combustion-supporting air, gas, and flue gas by the control mechanism, the control mechanism can respond promptly and accurately to the fluctuations in gas calorific value and pressure, ensuring the best combustion efficiency, improving energy utilization rate, reducing energy loss and the content of harmful substances in the waste gas. At the same time, the control mechanism can also adjust in real time, such as the air-fuel ratio, etc., based on the flame temperature to regulate the combustion state in the flue gas heating furnace, realizing the control of the flame temperature and the subsequent control of the flue gas output temperature. The overall control process is efficient and has a low degree of human participation, effectively ensuring the stability and safety of the system. The solutions in the embodiments of the present invention are widely applicable and can be applied to the combustion control of various combustion media such as blast furnace gas, converter gas, SRV melting furnace gas, coke oven gas, and natural gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 It is a schematic structural diagram of the industrial flue gas heating furnace system in the embodiments of the present invention.

[0094] Figure 2 This is a flowchart of the control method for the industrial flue gas heating furnace system in the embodiments of the present invention.

[0095] Figure 3 This is a program flowchart of the industrial flue gas heating furnace system in the embodiments of the present invention;

[0096] Figure 4 This is a principle block diagram of the industrial flue gas heating furnace system in the embodiments of the present invention;

[0097] Figure 5 This is a principle block diagram of the flame temperature control in the industrial flue gas heating furnace system in the embodiments of the present invention;

[0098] Figure 6 This is a principle block diagram of the flue gas temperature control in the industrial flue gas heating furnace system in the embodiments of the present invention;

[0099] Figure 7 This is a multi-point segmented parametric curve graph of the temperature deviation in the industrial flue gas heating furnace system in the embodiments of the present invention.

[0100] Reference numerals:

[0101] 1 - Flue gas heating furnace; 2 - Gas flow detector; 3 - Exhaust pipe; 4 - Combustion air pressure detector; 5 - Combustion air flow detector; 6 - Combustion air electric control valve; 7 - Combustion air pipeline; 8 - Gas pipeline; 9 - Gas pressure detector; 10 - Gas cut-off valve; 11 - Gas flow electric control valve; 12 - Burner nozzle; 13 - Flame temperature detector; 14 - Flue gas output temperature detector. Detailed implementation manners

[0102] Next, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings, but it is not a limitation of the present invention.

[0103] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the following description should not be regarded as a limitation, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present disclosure.

[0104] The accompanying drawings included in the specification and constituting a part of the specification illustrate the embodiments of the present disclosure, and together with the general description of the present disclosure given above and the detailed description of the embodiments given below are used to explain the principles of the present disclosure.

[0105] These and other features of the present invention will become apparent from the following description of the preferred forms of the embodiments given by way of non-limiting examples with reference to the accompanying drawings.

[0106] It should also be understood that although the present invention has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present invention, which have the features as described in the claims and thus are all within the protection scope defined hereby.

[0107] When combined with the accompanying drawings, the above and other aspects, features, and advantages of the present disclosure will become more apparent in view of the following detailed description.

[0108] Specific embodiments of the present disclosure will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis for the claims and a representative basis for teaching those skilled in the art to use the present disclosure in substantially any suitable detailed structure in various ways.

[0109] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment", or "in other embodiments", which may each refer to one or more of the same or different embodiments according to the present disclosure.

[0110] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0111] As Figure 1 shown, an industrial flue gas heating furnace system is provided in an embodiment of the present invention, including:

[0112] A flue gas heating furnace 1, on which a burner mechanism is provided. The flue gas heating furnace 1 is respectively connected to a flue gas inlet pipe and a flue gas outlet pipe 3 for receiving the flue gas to be treated and discharging the heated and purified flue gas.

[0113] A combustion air pipeline mechanism, which is connected to the flue gas heating furnace 1 through the burner mechanism to supply combustion air to the flue gas heating furnace 1.

[0114] A coal gas pipeline mechanism, which is connected to the flue gas heating furnace 1 through the burner mechanism to supply coal gas to the flue gas heating furnace 1; and

[0115] A control mechanism, which is electrically connected to at least the burner mechanism, the combustion air pipeline mechanism, and the coal gas pipeline mechanism to respectively control the supply of combustion air by the combustion air pipeline mechanism, the supply of coal gas by the coal gas pipeline mechanism, and the operation of the burner mechanism.

[0116] The industrial flue gas heating furnace 1 system in the embodiments of the present invention is fully automatically controlled with flameout interlock protection. Moreover, through the monitoring of combustion-supporting air, gas, and flue gas by the control mechanism, the control mechanism can respond promptly and accurately to the calorific value and pressure fluctuations of the gas, ensuring the best combustion efficiency, improving energy utilization rate, reducing energy loss, and the content of harmful substances in the waste gas. At the same time, the control mechanism can also adjust in real time, such as the air-fuel ratio, based on the flame temperature to regulate the combustion state in the flue gas heating furnace 1, realizing the control of the flame temperature and the subsequent control of the flue gas output temperature. The overall control process is efficient with low human participation, effectively ensuring the stability and safety of the system. The solutions in the embodiments of the present invention are widely applicable and can be used for the combustion control of various combustion media such as blast furnace gas, converter gas, SRV melting furnace gas, coke oven gas, and natural gas.

[0117] Specifically, the burner mechanism in this embodiment at least includes a burner assembly, a flame monitor, a flame temperature detector 13, and a flue gas output temperature detector 14. Among them, the burner assembly includes a high-voltage ignition transformer, an ignition electrode, and an ignition burner. The high-voltage ignition transformer is arranged in the on-site ignition box, and the ignition electrode and the ignition burner are located in the burner nozzle 12 in the flue gas heating furnace 1. During the ignition operation, it is remote high-voltage electrode ignition to ignite the start burner nozzle 12. The flame monitor is a flame monitoring probe, which is arranged on the flame monitoring hole of the burner nozzle 12 so that the control mechanism can perform flameout protection control according to the flame combustion and extinguishing states. The flame temperature detector 13 includes a flame temperature sensor, which is installed near the flame outlet of the burner nozzle 12 and is used to collect the combustion flame temperature to assist the control mechanism in controlling the mixing ratio of combustion-supporting air and gas. The flue gas output temperature detector 14 includes a flue gas output temperature sensor, which is installed at the flue gas outlet of the flue gas heating furnace 1 and is used to collect the output flue gas temperature to assist the control mechanism in controlling the calibration of the output flue gas temperature.

[0118] Furthermore, the combustion-supporting air pipeline mechanism at least includes a combustion-supporting air pipeline 7 and a combustion-supporting air pressure detector 4, a combustion-supporting air flow detector 5, and a combustion-supporting air electric control valve 6 arranged on the combustion-supporting air pipeline 7. These detectors and control valves are used to assist in controlling the combustion-supporting air flow. Among them, the combustion-supporting air pressure detector 4 includes a buffer pipe installed on the combustion-supporting air pipeline 7 and a pressure transmitter arranged on the buffer pipe. The combustion-supporting air flow detector 5 includes a throttling mechanism, a three-valve group, and a differential pressure transmitter. The throttling mechanism is installed on the combustion-supporting air pipeline 7, the three-valve group is installed on the throttling mechanism, and the differential pressure transmitter is installed on the three-valve group.

[0119] Further, the gas pipeline mechanism at least includes a gas pipeline 8 and a gas pressure detector 9, a gas flow detector 2, a gas cut-off valve 10, and a gas flow electric regulating valve 11 provided on the gas pipeline 8. These detectors and regulating valves are used to assist in controlling the gas flow. Among them, the gas pressure detector 9 also includes a buffer pipe and a pressure transmitter, and its installation position is the same as that of the corresponding device in the combustion-supporting air pressure detector 4; the gas flow detector 2 also includes a throttling mechanism, a three-valve group, and a differential pressure transmitter, and the installation positions of the three are the same as those of the corresponding devices in the combustion-supporting air flow detector 5.

[0120] The control mechanism at least includes a CBR case inference machine with a parameter matrix database and an air-fuel ratio band fuzzy inference mechanism that can infer the air-fuel ratio based on historical cases, an optimal air-fuel ratio fuzzy controller with an air-fuel ratio fuzzy equation and an optimal air-fuel ratio selection mechanism, and a flue gas temperature fuzzy PID controller including a flue gas fuzzy controller and a PID controller. Among them, the optimal air-fuel ratio fuzzy controller is used to tune the fuzzy model of the relationship between the flame temperature and the real-time air-fuel ratio and perform optimal combustion air-fuel ratio control. The flue gas temperature fuzzy PID controller is used to control the flue gas output temperature according to the collected flue gas output temperature and the given value of the flue gas output temperature required by the downstream process system.

[0121] Preferably, the control mechanism in this embodiment further includes a combustion-supporting air flow controller and a gas flow controller. The combustion-supporting air flow controller is used to control the action of the combustion-supporting air electric regulating valve 6 according to the combustion-supporting air flow control signal issued by the system to adjust the combustion-supporting air flow; the gas flow controller is used to control the action of the gas flow electric regulating valve 11 according to the gas flow control signal issued by the system to adjust the gas flow. Among them, the above control signals can be determined according to user instructions, or the pressures detected by the pressure detectors of each pipeline (including the combustion-supporting air pressure detector 4 and the gas pressure detector 9), or the flame state detected by the flame monitor, etc. In addition, the control mechanism also includes a gas cut-off valve controller, which is used to control the action of the gas cut-off valve 10 according to the flame state signal to shut off or open the gas. Of course, when the control mechanism detects an abnormal pressure in the gas pipeline 8, the gas cut-off valve 10 can also be controlled to act by the gas cut-off valve controller to cut off the gas.

[0122] The control mechanism in this embodiment adopts a CBR case inference machine for optimal air-fuel ratio fuzzy control, which can respond promptly and accurately to gas calorific value and pressure fluctuations, ensure the best combustion efficiency, improve energy utilization rate, and reduce energy loss and the content of harmful substances in the waste gas. At the same time, the PID controller can also adopt the fuzzy PID control method to achieve accurate control of the entire furnace burning process and a large range, further improving the response speed and control accuracy.

[0123] Such asFigures 2 to 6 As shown in Figures 2 to 6 , an embodiment of the present invention also provides a control method for an industrial flue gas heating furnace system, including:

[0124] Receiving the flue gas, combustion-supporting air, and gas to be processed from the flue gas inlet pipe, combustion-supporting air pipe, and gas pipe respectively;

[0125] Starting the burner mechanism to ignite the flue gas heating furnace;

[0126] Real-time monitoring of the flame state in the flue gas heating furnace through a flame monitor;

[0127] When abnormal flameout occurs, cutting off the gas pipeline through a gas cut-off valve and issuing an alarm;

[0128] If there is no flameout, obtaining the actual flame temperature value FIpv(t) in real time through a flame temperature detector;

[0129] If the actual flame temperature value does not meet the preset value range, using the case-based reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) and the minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state through the optimal air-fuel ratio fuzzy controller;

[0130] Obtaining the actual gas flow value GFpv(t) through a gas flow detector;

[0131] Calculating the given value AFsp(t) of the combustion-supporting air flow through the actual gas flow value: AFsp(t)=A(t)*GFpv(t);

[0132] Obtaining the actual combustion-supporting air flow value AFpv(t) through a combustion-supporting air flow detector;

[0133] Adjusting the combustion-supporting air flow based on the given value of the combustion-supporting air flow and the actual combustion-supporting air flow value. Specifically, adjusting the combustion-supporting air flow through an electric control valve for combustion-supporting air so that the actual flame temperature value after the combustion-supporting air and gas are mixed and burned under the current flow meets the preset value range;

[0134] After the actual flame temperature value meets the preset value range, obtaining the actual flue gas output temperature value FUpv(t) through a flue gas output temperature detector;

[0135] If the flue gas output temperature value does not match the target value, inferring the control parameters of the PID controller in the control mechanism in the current state based on the actual flue gas output temperature value and the target value;

[0136] Using the calculated value du(t) obtained by the PID controller based on the control parameters as the additional given value of the gas flow;

[0137] Adjust the gas flow based on the additional set value of the gas flow so that the actual temperature value of the flue gas generated under the current combustion state meets the target value.

[0138] Of course, in the above process, the system also needs to continuously monitor the pressure in the combustion air pipeline and the gas pipeline according to the values detected by the combustion air pressure detector and the gas pressure detector, so as to ensure that the gas flow in each pipeline meets the needs of flue gas combustion on the premise of meeting the target pressures of each pipeline.

[0139] The control method of the industrial flue gas heating furnace system in the embodiment of the present invention can achieve the effect of full-automatic control of the flue gas heating and purification process, without too much human participation, greatly simplifying the control operations of the operators. Moreover, through the monitoring of combustion air, gas and flue gas by the control mechanism, the control mechanism can respond to gas calorific value and pressure fluctuations in a timely and accurate manner, ensure the best combustion efficiency, improve energy utilization rate, and reduce energy loss and the content of harmful substances in the waste gas. At the same time, the system can also adjust, for example, the air-fuel ratio in real time based on the flame temperature to adjust the combustion state in the flue gas heating furnace, realize the control of the flame temperature, and the control of the subsequent flue gas output temperature, effectively ensuring the flue gas heating and purification efficiency and degree, and reducing energy loss.

[0140] Specifically, in this embodiment, when starting the burner mechanism and igniting the flue gas heating furnace, it includes:

[0141] Start the purging program and ignition program of the gas pipeline according to the system ignition command, ignite the burner nozzle, and start burning the furnace, that is, ignite the flue gas heating furnace and burn the mixture of combustion air and gas inside it to heat up the flue gas, achieve the purification effect to generate high-temperature flue gas, and mix it into the flue gas pipeline to achieve the flue gas heating and purification effect.

[0142] Among them, in this embodiment, when it is determined that the actual value of the flame temperature does not meet the preset value range, it specifically includes:

[0143] Taking the flame temperature set value FIsp(t) as the target value and the output value FIpv(t) of the flame temperature detector as the actual value, calculate the flame temperature deviation E fi (KT s ):

[0144] E fi (KT s ) = FIsp(KT s ) - FIpv(KT s ) (1)

[0145] Among them, K is the current sampling number, T s is the sampling period, and take E fi (KT s) The value is passed to the optimal air-fuel ratio fuzzy controller in the control mechanism, and the optimal air-fuel ratio fuzzy controller determines whether the flame temperature deviation meets the preset value range.

[0146] Further, in this embodiment, when using the CBR case reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) of the optimal air-fuel ratio and the minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state through the optimal air-fuel ratio fuzzy controller includes:

[0147] The actual value FIpv(t) of the flame temperature and the air-fuel ratio value A(t) are detected in real time, and the data is stored and recorded according to the sampling period Ts, and the [FIpv(KTs), A(KTs)] matrix database is created;

[0148] According to the execution period Tc of the case reasoning machine, the [FIpv(KTs), A(KTs)] matrix is polled; the temperature range from the maximum value FIpv(max) of FIpv(t) to FIpv(max)-100°C is taken, and all the air-fuel ratio values within this temperature range are retrieved and arranged in ascending order to form an array (a) of [A(xTs), A(yTs), …… A(iTs)]; the elements in the array (a) with a numerical deviation less than the target range are grouped into several sub-arrays (b)(c)……(n); the number of elements in the array (a) and each sub-array (b)(c)……(n) is counted; the arrays with the number of elements greater than 5% of the total number of elements in the array (a) in each sub-array are selected to form a new array (A); the minimum element value A(min) and the maximum element value A(max) in the array (A) are used as the air-fuel ratio band limit values and passed to the optimal air-fuel ratio fuzzy controller;

[0149] According to the flame temperature deviation Efi(KTs) at the current sampling moment and the flame temperature deviation Efi(KTs - Ts) at the previous sampling moment, the change rate Efir(KTs) of the flame temperature deviation at the current sampling moment is calculated:

[0150] Efir(KTs) = [Efi(KTs) - Efi(KTs - Ts)] / Ts (2)

[0151] When Efi(KTs) > 0°C, if Efir(KTs) < -6°C / s or Efir(KTs) > 0°C / s, then the current air-fuel ratio A(t1) is output as A(t):

[0152] A(t) = A(KTs) - Efir(KTs) / d (3)

[0153] If -0.3°C / s < Efir(KTs) < 0°C / s, then the current air-fuel ratio A(t1) is output as A(t):

[0154] A(t) = A(KTs) + fir(KTs) / d (4)

[0155] Otherwise, the current air-fuel ratio A(t1) remains unadjusted;

[0156] When Efi(KTs) < -100°C, if Efir(KTs) < 0°C / s, the current air-fuel ratio A(t1) is output as calculated by Equation (3); otherwise, the current air-fuel ratio A(t1) remains unadjusted;

[0157] When -100°C ≤ Efi(KTs) ≤ 0°C: Calculate the air-fuel ratio A(t) according to the air-fuel ratio fuzzy equation:

[0158]

[0159] where, [b 2 -4a(c - FIpv(KTs))] ≥ 0;

[0160] Obtain the air-fuel ratios A(t)1 and A(t)2. If A(min) ≤ A(t)1 ≤ A(max) and A(min) ≤ A(t)2 ≤ A(max), then output the current air-fuel ratio A(t):

[0161] A(t) = MIN[A(t)1), A(t)2] (6)

[0162] If A(min) ≤ A(t)1 ≤ A(max), and A(t)2 < A(min) or A(max) < A(t)2, then output the previous air-fuel ratio A(t):

[0163] A(t) = A(t)1 (7)

[0164] If A(min) ≤ A(t)2 ≤ A(max), and A(t)1 < A(min) or A(max) < A(t)1, then output the previous air-fuel ratio A(t):

[0165] A(t) = A(t)2 (8)

[0166] Otherwise, the current air-fuel ratio A(t) remains unadjusted.

[0167] Among them, d in the above Equations (3) and (4) is a constant, and a, b, and c in Equation (5) are constants.

[0168] Furthermore, as Figure 7 shown, in this embodiment, when it is determined that the flue gas output temperature value does not match the target value and the control parameters of the PID controller in the control mechanism in the current state are deduced based on the actual value and the target value of the flue gas output temperature, it includes:

[0169] Taking the flue gas temperature set value FUsp(t) as the target value and the output value FUpv(t) of the flue gas temperature detector as the actual value, calculate the flue gas temperature deviation Efu(KTs) at the current sampling moment:

[0170] Efu(KTs) = FUsp(KTs) - FUpv(KTs) (9)

[0171] According to the flue gas temperature deviation Efu(KTs) at the current sampling moment and the flue gas temperature deviation Efu(KTs - Ts) at the previous sampling moment, calculate the change rate Efur(KTs) of the flue gas temperature deviation at the current sampling moment:

[0172] Efur(KTs) = [Efu(KTs) - Efu(KTs - Ts)] / Ts (10)

[0173] Perform multi-point correction on the flue gas temperature deviation, including dividing the flue gas temperature deviation value into 7 segments according to its absolute value, i.e., 0 ≤ |Efu(KTs)| < E1; E1 ≤ |Efu(KTs)| < E2; E2 ≤ |Efu(KTs)| < E3; E3 ≤ |Efu(KTs)| < E4; E4 ≤ |Efu(KTs)| < E5; E5 ≤ |Efu(KTs)| < E6; E6 ≤ |Efu(KTs)|;

[0174] where E1 - E6 are all constants, and 0 < E1 < E2 < E3 < E4 < E5 < E6;

[0175] When E5 ≤ |Efu(KTs)|, plan the target change rate Efursp(t) of the flue gas temperature deviation:

[0176] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E5 - E6) / Ta (11)

[0177] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters of this stage as P = P6, I = I6, D = D6;

[0178] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters of this stage as P = P61, I = 0, D = D61; where Ta is the minimum tuning period of the controller parameters, and P6, P61, I6, D6, D61 are non-zero constants;

[0179] When E4 ≤ |Efu(KTs)| < E5, plan the target change rate Efursp(t) of the flue gas temperature deviation:

[0180] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E4 - E5) / Ta (12)

[0181] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P5, I = I5, D = D5;

[0182] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P51, I = 0, D = D51; where P5, P51, I5, D5, D51 are non - zero constants;

[0183] When E3 ≤ |Efu(KTs)| < E4, the planned target flue gas temperature deviation change rate Efursp(t):

[0184] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E3 - E4) / (2Ta) (13)

[0185] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P4, I = I4, D = D4;

[0186] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P41, I = 0, D = D41; where P4, P41, I4, D4, D41 are non - zero constants;

[0187] When E2 ≤ |Efu(KTs)| < E3, the planned target flue gas temperature deviation change rate Efursp(t):

[0188] Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E2 - E3) / (3Ta)(14)

[0189] If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P3, I = I3, D = D3;

[0190] If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P31, I = I31, D = D31; where P3, P31, I3, I31, D3, D31 are non - zero constants;

[0191] When E1 ≤ |Efu(KTs)| < E2, set the PID controller parameters for this stage as P = P2, I = I2, D = D2; where P2, I2, D2 are non - zero constants;

[0192] When |Efu(KTs)| < E1, set the PID controller parameters in this stage as P = P1, I = I1, D = D1; where P1, I1, and D1 are non-zero constants.

[0193] Furthermore, in this embodiment, when using the calculated value U(t) obtained by the PID controller based on the control parameters as the additional given value of the gas flow rate, it includes:

[0194] When E2 < |E fu (KT s )|, take the change rate of the flue gas temperature deviation E fur (KT s ) at the current sampling moment, and the planned target flue gas temperature deviation change rate E fur sp(KT s ) at the current sampling moment as the input values of the PID controller, and use the following formula (15) as the additional given value du(t) of the gas flow controller:

[0195] du(t) = P * [e Er (KT s ) - e Er (KT s - T s )] + I * e Er (KT s ) + D * [e Er (KT s ) - 2e Er (KT s - T s ) + e Er (KT s - 2T s )] (15)

[0196] In formula (15), e Er (KT s ) = [E fur sp(KT s ) - E fur (KT s )] (16)

[0197] The PID controller parameters take the P, I, and D values of the corresponding control stage where |E fu (KT s )| is located;

[0198] In formula (16), E fur sp(KT s ) takes |E fu (KT s) | The calculated values of the corresponding control stages (11), (12), (13), and (14);

[0199] When | E fu (KT s ) | ≤ E2, the flue gas temperature deviation E fu (KT s ) at the current sampling moment is used as the input of the PID controller, and the following formula (17) is used as the additional set value du(t) of the gas flow controller:

[0200] du(t) = P * [E fu (KT s ) - E fu (KT s - T s )] + I * E fu (KT s ) + D * [E fu (KT s ) - 2E fu (KT s - T s ) + E fu (KT s - 2T s )] (17)

[0201] Among them, the PID controller parameters are taken as the P, I, and D values of the corresponding control stage where | E fu (KT s ) | is located;

[0202] The output value U(t) of the PID controller is used as the additional set value of the gas flow, where:

[0203] U(t) = U + du(t) (18)

[0204] In formula (18), U is the initial set value of the gas flow, which is a constant, and du(t) is obtained from calculation formulas (15) and (17).

[0205] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the electronic device to which the above-described data processing method is applied can refer to the corresponding description in the foregoing product embodiments, and will not be elaborated herein.

[0206] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.

Claims

1. A control method for an industrial flue gas heating furnace system, characterized in that, Including: Receiving the flue gas, combustion-supporting air, and coal gas to be processed from the smoke inlet pipe, combustion-supporting air pipe, and coal gas pipe respectively; Starting the burner mechanism to ignite the flue gas heating furnace; Real-time monitoring the flame state in the flue gas heating furnace through a flame monitor; When abnormal flameout occurs, cutting off the coal gas pipe and sending an alarm; If there is no flameout, obtaining the actual flame temperature value FIpv(t) in real time through a flame temperature detector; If the actual flame temperature value does not meet the preset value range, using the case-based reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) and minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state through the optimal air-fuel ratio fuzzy controller; Obtaining the actual coal gas flow value GFpv(t) through a coal gas flow detector; Calculating the given value AFsp(t) of the combustion-supporting air flow through the actual coal gas flow value: AFsp(t) = A(t) * GFpv(t); Obtaining the actual combustion-supporting air flow value AFpv(t) through a combustion-supporting air flow detector; Adjusting the combustion-supporting air flow based on the given value of the combustion-supporting air flow and the actual combustion-supporting air flow value so that the actual flame temperature value after the combustion-supporting air and coal gas are mixed and burned under the current flow meets the preset value range; After the actual flame temperature value meets the preset value range, obtaining the actual flue gas output temperature value FUpv(t) through a flue gas output temperature detector; If the flue gas output temperature value does not match the target value, inferring the control parameters of the PID controller in the control mechanism in the current state based on the actual flue gas output temperature value and the target value; Using the calculated value du(t) obtained by the PID controller based on the control parameters as the additional given value of the coal gas flow; Adjusting the coal gas flow based on the additional given value of the coal gas flow so that the actual temperature value of the flue gas generated under the current combustion state meets the target value.

2. The method according to claim 1, characterized in that, If the actual flame temperature value does not meet the preset value range specifically: Taking the flame temperature setpoint FIsp(t) as the target value and the output value FIpv(t) of the flame temperature detector as the actual value, calculate the flame temperature deviation E at the current sampling moment fi (KT s ): E fi (KT s ) = FIsp(KT s ) - FIpv(KT s ) (1) where K is the current sampling number, T s is the sampling period, and the value of E fi (KT s ) is passed to the optimal air-fuel ratio fuzzy controller in the control mechanism, and the optimal air-fuel ratio fuzzy controller determines whether the flame temperature deviation satisfies a preset value range.

3. The method according to claim 2, wherein The process of using the case-based reasoning machine in the control mechanism to determine the optimal combustion air-fuel ratio, setting the maximum value A(max) and minimum value A(min) of the optimal air-fuel ratio, and outputting the optimal air-fuel ratio value A(t) in the current state includes: Real-time detecting the actual flame temperature value FIpv(t) and the real-time air-fuel ratio value A(t), storing and recording the data according to the sampling period Ts, and creating a [FIpv(KTs), A(KTs)] matrix database; Poll the [FIpv(KTs), A(KTs)] matrix according to the execution period Tc of the instance inference engine; take the temperature range from the maximum value FIpv(max) of FIpv(t) to FIpv(max) - 100°C, and retrieve the array M composed of all air-fuel ratio values in ascending order within this temperature range, namely [A(xTs), A(yTs), …… A(iTs)]; group the elements in the array M whose numerical deviation is less than the target range into several sub-arrays M1, M2, …… Mn; count the number of elements in the array M and each sub-array M1, M2, …… Mn; select the sub-arrays whose number of elements is greater than 5% of the total number of elements in the array M to form a new array Q; use the minimum element value Q(min) and the maximum element value Q(max) in the array Q as the air-fuel ratio band limit values and pass them to the optimal air-fuel ratio fuzzy controller; Calculate the change rate of the flame temperature deviation Efir(KTs) at the current sampling moment according to the flame temperature deviation Efi(KTs) at the current sampling moment and the flame temperature deviation Efi(KTs - Ts) at the previous sampling moment: Efir(KTs) = [Efi(KTs) - Efi(KTs - Ts)] / Ts (2) When Efi(KTs) > 0°C, if Efir(KTs) < -6°C / s or Efir(KTs) > 0°C / s, then output the current air-fuel ratio A(t1) as A(t): A(t) = A(KTs) - Efir(KTs) / d (3) If -0.3°C / s < Efir(KTs) < 0°C / s, then output the current air-fuel ratio A(t1) as A(t): A(t) = A(KTs) + Efir(KTs) / d (4) Otherwise, the current air-fuel ratio A(t1) remains unchanged; When Efi(KTs) < -100°C, if Efir(KTs) < 0°C / s, output the current air-fuel ratio A(t1) obtained according to equation (3); otherwise, the current air-fuel ratio A(t1) remains unchanged; When -100°C ≤ Efi(KTs) ≤ 0°C: Calculate the air-fuel ratio A(t) according to the air-fuel ratio fuzzy equation: A(t) = [-b ± √(b 2 - 4a(c - FIpv(KTs)))] / 2a (5) Among them, [b 2 -4a(c - FIpv(KTs))] ≥ 0; Obtain the air-fuel ratios A(t)1 and A(t)2. If A(min) ≤ A(t)1 ≤ A(max) and A(min) ≤ A(t)2 ≤ A(max), then output the current air-fuel ratio A(t): A(t) = MIN[A(t)1), A(t)2] (6) If A(min) ≤ A(t)1 ≤ A(max), and A(t)2 < A(min) or A(max) < A(t)2, then output the previous air-fuel ratio A(t): A(t) = A(t)1 (7) If A(min) ≤ A(t)2 ≤ A(max), and A(t)1 < A(min) or A(max) < A(t)1, then output the previous air-fuel ratio A(t): A(t) = A(t)2 (8) Otherwise, the current air-fuel ratio A(t) remains unchanged; Wherein, d in the above equations (3) and (4) is a constant, and a, b, and c in equation (5) are constants.

4. The method according to claim 1, wherein If the flue gas output temperature value does not match the target value, the control parameters of the PID controller in the control mechanism in the current state deduced based on the actual value and the target value of the flue gas output temperature include: Taking the flue gas temperature set value FUsp(t) as the target value and the output value FUpv(t) of the flue gas temperature detector as the actual value, calculate the flue gas temperature deviation Efu(KTs) at the current sampling moment: Efu(KTs) = FUsp(KTs) - FUpv(KTs) (9) According to the flue gas temperature deviation Efu(KTs) at the current sampling moment and the flue gas temperature deviation Efu(KTs - Ts) at the previous sampling moment, calculate the change rate Efur(KTs) of the flue gas temperature deviation at the current sampling moment: Efur(KTs) = [Efu(KTs) - Efu(KTs - Ts)] / Ts (10) Perform multi-point correction on the flue gas temperature deviation, including dividing the flue gas temperature deviation value into 7 segments according to its absolute value, i.e., 0 ≤ |Efu(KTs)| < E1; E1 ≤ |Efu(KTs)| < E2; E2 ≤ |Efu(KTs)| < E3; E3 ≤ |Efu(KTs)| < E4; E4 ≤ |Efu(KTs)| < E5; E5 ≤ |Efu(KTs)| < E6; E6 ≤ |Efu(KTs)|; Among them, E1 - E6 are all constants, and 0 < E1 < E2 < E3 < E4 < E5 < E6; When E5 ≤ |Efu(KTs)|, plan the target flue gas temperature deviation change rate Efursp(t): Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E5 - E6) / Ta (11) If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters in this stage as P = P6, I = I6, D = D6; If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters in this stage as P = P61, I = 0, D = D61; where Ta is the minimum tuning period of the controller parameters, and P6, P61, I6, D6, D61 are non-zero constants; When E4 ≤ |Efu(KTs)| < E5, plan the target flue gas temperature deviation change rate Efursp(t): Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E4 - E5) / Ta (12) If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters in this stage as P = P5, I = I5, D = D5; If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters in this stage as P = P51, I = 0, D = D51; where P5, P51, I5, D5, D51 are non-zero constants; When E3 ≤ |Efu(KTs)| < E4, plan the target flue gas temperature deviation change rate Efursp(t): Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E3 - E4) / (2Ta) (13) If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P4, I = I4, D = D4; If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P41, I = 0, D = D41; where P4, P41, I4, D4, D41 are non - zero constants; When E2 ≤ |Efu(KTs)| < E3, the planned target flue gas temperature deviation change rate Efursp(t): Efursp(t) = [Efu(KTs) / |Efu(KTs)|] * (E2 - E3) / (3Ta) (14) If |Efursp(t)| ≤ |Efur(KTs)|, set the PID controller parameters for this stage as P = P3, I = I3, D = D3; If |Efursp(t)| > |Efur(KTs)|, set the PID controller parameters for this stage as P = P31, I = I31, D = D31; where P3, P31, I3, I31, D3, D31 are non - zero constants; When E1 ≤ |Efu(KTs)| < E2, set the PID controller parameters for this stage as P = P2, I = I2, D = D2; where P2, I2, D2 are non - zero constants; When |Efu(KTs)| < E1, set the PID controller parameters for this stage as P = P1, I = I1, D = D1; where P1, I1, D1 are non - zero constants.

5. The method according to claim 4, wherein The calculated value U(t) obtained by the PID controller based on the control parameters as the additional given value of the gas flow rate includes: When E2 < |E fu (KT s )|, the change rate E fur (KT s ) of the flue gas temperature deviation at the current sampling moment, and the change rate E fur sp(KT s ) of the planned target flue gas temperature deviation at the current sampling moment are used as the input values of the PID controller, and the following formula (15) is used as the additional given value du(t) of the gas flow controller: du(t) = P * [e Er (KT s ) - e Er (KT s - T s )] + I * e Er (KT s ) + D * [e Er (KT s ) - 2e Er (KT s - T s ) + e Er (KT s - 2T s )] (15) e in formula (15) Er (KT s ) = [E fur sp(KT s ) - E fur (KT s )] (16) The PID controller parameters are taken as |E fu (KT s ) the P, I, and D values at the corresponding control stage; E in formula (16) fur sp(KT s ) takes the calculated values of formulas (11), (12), (13), and (14) in the corresponding control stage where |E fu (KT s )| is located; When |E fu (KT s )| ≤ E2, the flue gas temperature deviation E fu (KT s ) at the current sampling moment is used as the input of the PID controller, and the additional given value du(t) of the gas flow controller is calculated according to the following formula (17): du(t) = P * [E fu (KT s ) - E fu (KT s - T s ) + I * E fu (KT s ) + D * [E fu (KT s ) - 2E fu (KT s - T s ) + E fu (KT s - 2T s )] (17) Among them, the PID controller parameters take the P, I, and D values at the corresponding control stage where |E fu (KT s )| is located; Taking the output value U(t) of the PID controller as the additional given value of the gas flow rate, where: U(t) = U + du(t) (18) In formula (18), U is the initial given value of the gas flow rate, which is a constant, and du(t) is obtained from calculation formulas (15) and (17).

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