Intelligent combustion optimization control system for double-beam lime kiln with coal powder blending combustion

Abstract

The application discloses a kind of double-beam lime kiln intelligent combustion optimization control system of coal powder blending combustion, the system includes fuel control loop system, combustion air control loop system and cooling air control loop system, while taking into account single burning and blending burning two working conditions, under the premise of guaranteeing output stability, stable fuel quantity, make kiln body temperature smooth, reach the purpose of saving fuel and stable ash quality;Oxygen content optimization model can optimize the oxygen content required for optimal combustion effect, improve combustion efficiency to realize energy saving and consumption reduction;Automatic adjustment cooling fan, realizes the relative stability of ash temperature and lower suction air beam temperature when output changes, improves the safety of kiln body;Greatly reduce the labor intensity of operator, improve the stability and safety of lime kiln production.

Description

Technical Field

[0001] This invention relates to the field of combustion control technology for double-beam lime kilns, specifically to an intelligent combustion optimization control system for double-beam lime kilns that incorporates pulverized coal. Background Technology

[0002] With the continuous improvement of metallurgical enterprises' production capacity, the number of production equipment using blast furnace gas and converter gas as fuel is also increasing. This can easily lead to a shortage of blast furnace gas and converter gas to meet the production needs of double-beam lime kilns. To stabilize production and meet the downstream demand for steelmaking lime, a solution has been proposed: using pulverized coal as a supplementary fuel when blast furnace gas and converter gas are insufficient.

[0003] Due to significant pressure fluctuations in the gas pipeline network in the metallurgical industry, and the fact that pulverized coal feeding is mostly manual, the control of gas and pulverized coal often results in excessive or insufficient supply. This leads to unstable production in double-beam lime kilns, large fluctuations in the quality of the lime, and an increase in the over-burning and under-burning rates, directly affecting the quality of the finished product. Furthermore, the fluctuations in gas pipeline network pressure and the instability of pulverized coal feeding mean that the combustion air under manual control cannot be adjusted in time, affecting fuel combustion efficiency and flue gas pollutant content, which in turn affects the heat inside the kiln, resulting in unstable ash discharge temperature.

[0004] In summary, in order to reduce the labor intensity of operators, improve the stability and safety of system operation, and avoid unnecessary energy waste, there is an urgent need to find an intelligent combustion optimization control system for double-beam lime kilns that co-fire pulverized coal. Summary of the Invention

[0005] Therefore, this invention provides an intelligent combustion optimization control system for a double-beam lime kiln that co-fires pulverized coal, to ensure a stable fuel supply for the double-beam lime kiln, to achieve intelligent adjustment of the combustion air intake, and to automatically optimize the oxygen content, thereby achieving energy-saving and environmentally friendly operation of the lime kiln.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal, the system comprising a fuel control loop system, a combustion air control loop system, and a cooling air control loop system;

[0007] The fuel control loop system includes a simulated energy balance control module and a working condition identification module. The simulated energy balance control module uses the calculated total heat required for qualified ash discharge (i.e., the calculated total heat demand) as the set value and the calculated total heat of fuel entering the furnace (i.e., the calculated actual total heat) as the measured value. The two are used to balance the furnace operation. The module adjusts the opening of the controlled object based on the current working condition identification result. If the current working condition identification result indicates co-firing, the pulverized coal controller is invoked to adjust the opening of the pulverized coal metering screw. If the current working condition identification result indicates single-fuel combustion, the gas controller is invoked to adjust the opening of the gas regulating valve for gas feeding. The working condition identification module is used to identify the current working condition and determine whether it is co-firing or single-fuel combustion.

[0008] The combustion air control loop system is used to adjust the frequency converter of the combustion air supply by comparing the set value and the actual value of the oxygen content, so as to keep the actual value of the oxygen content of the combustion air near the set value. The set value of the oxygen content is found by the oxygen content self-optimization function to find the oxygen content that meets the optimal combustion conditions.

[0009] The cooling air control loop system is used to take the upper limit of ash discharge temperature and the upper limit of lower suction beam temperature as dual control targets, and the real-time ash discharge output as feedforward to adjust the frequency conversion opening of the cooling fan to ensure that the ash discharge temperature and the lower suction beam temperature do not exceed the limit.

[0010] Furthermore, the fuel control loop system also includes a product qualification heat demand prediction model. The product qualification heat demand prediction model is used to calculate the average heat Q_AVG and lime kiln ash discharge flow rate FT_CH required to produce one ton of lime that meets the qualification standard based on the ash product analysis data. Based on these two data, the total heat demand Q_SP1 = Q_AVG * FT_CH is calculated.

[0011] Furthermore, the fuel control loop system also includes a kiln temperature correction model, which is used to correct the calculated total heat demand value based on the kiln temperature.

[0012] Furthermore, the fuel control loop system also includes a soft measurement model for pulverized coal flow and a pulverized coal flow selection processing module. The soft measurement model for pulverized coal flow is used to calculate the soft measurement value of pulverized coal flow, FMF_RCL1, based on the weight of the pulverized coal silo using a linear regression algorithm. The pulverized coal flow selection processing module is used to calculate FMF_RCL2 = HZ_JL * FMF_JLAVG using the metering screw opening HZ_JL and the average pulverized coal flow per unit opening, FMF_JLAVG. When pulverized coal is replenished in the pulverized coal silo, the soft measurement value of pulverized coal flow, FMF_RCL, is FMF_RCL2; otherwise, FMF_RCL = FMF_RCL1. Based on manual selection, the pulverized coal flow, FT_MF, is represented by either the soft measurement value FMF_RCL or the actual measured value FMF_SJ.

[0013] The simulated energy balance control module is used to calculate the actual total heat Q_PV, where Q_PV=FT_RQ*(RZ_GL*FT_GL / (FT_GL+FT_ZL)+RZ_GL*FT_GL / (FT_GL+FT_ZL))+FT_MF*RZ_MF, the calorific value of blast furnace gas is RZ_GL, the calorific value of blast furnace gas is FT_GL, the calorific value of converter gas is RZ_ZL, the calorific value of converter gas is FT_ZL, the calorific value of mixed gas is FT_RQ, and the calorific value of pulverized coal is RZ_MF. The module setpoint is Q_SP=Q_SP1+Q_SP2, and the measured value is used to calculate the actual total heat Q_PV.

[0014] Furthermore, the fuel control loop system also includes a gas pressure limiting control module, which participates in the control of the gas regulating valve under both single-burning and blending conditions. When the gas pressure exceeds the upper limit, it outputs a prohibition signal to the gas controller; when the gas pressure exceeds the lower limit, it outputs a prohibition signal to the gas controller.

[0015] Furthermore, the combustion air control loop system includes an oxygen content optimization controller, an oxygen content regulator, and a feedforward for calculating actual total heat correction. The oxygen content optimization controller is used to automatically optimize the oxygen content and output a set oxygen content value according to a set optimization step size. The oxygen content regulator is used to adjust the frequency conversion opening of the air supply based on the deviation between the set oxygen content value output by the oxygen content optimization controller and the actual value measured by the oxygen content measuring instrument. The output of the feedforward for calculating actual total heat correction adjusts the frequency conversion opening of the combustion air together with the oxygen content regulator.

[0016] Furthermore, the cooling air control loop system includes an upper limit controller for ash discharge temperature, an upper limit controller for the lower suction beam temperature, and a feedforward controller for ash discharge output correction. The sum of these three is the total loop output, which controls the frequency conversion opening of the cooling fan. The measured value of the upper limit controller for ash discharge temperature is ash discharge temperature TCH_PV. The setpoint TCH_SP tracks the measured value when the ash discharge temperature does not exceed the limit, and becomes the upper limit value TCH_HSP when the ash discharge temperature exceeds the limit. The output is the frequency conversion opening of the cooling fan TCH_AV. The lower suction beam temperature... The upper limit controller measures the temperature of the lower suction beam (TXQL_PV). The setpoint (TXQL_SP) tracks the measured value when the temperature of the lower suction beam does not exceed the limit, and becomes the upper limit value (TXQL_HSP) of the lower suction beam temperature when the temperature exceeds the limit. The output is the frequency conversion opening degree (TXQL_AV) of the cooling fan. The ash output setpoint (CH_SP) is the current ash output (CH_PV) recorded when switching to automatic mode. The output of this feedforward is CH_AV = K2 * (CH_PV - CH_SP), where K2 is the setpoint.

[0017] The present invention has the following advantages:

[0018] This invention proposes an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal co-firing. The system includes a fuel control loop system, a combustion air control loop system, and a cooling air control loop system. It simultaneously accommodates both single-firing and co-firing conditions, stabilizing fuel quantity and kiln temperature while ensuring stable output, thereby achieving fuel savings and stable ash quality. The oxygen content optimization model can find the optimal oxygen content required for combustion effect, improving combustion efficiency and achieving energy saving and consumption reduction. The automatic adjustment of the cooling fan ensures relative stability of ash temperature and lower suction beam temperature when output changes, improving kiln safety. It greatly reduces the labor intensity of operators and improves the stability and safety of lime kiln production. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the fuel control loop system in an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal provided in Embodiment 1 of the present invention;

[0021] Figure 2 This is a schematic diagram of the combustion air control loop system in an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal provided in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the automatic optimization process of the oxygen content optimization controller in an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal provided in Embodiment 1 of the present invention.

[0023] Figure 4 This is a schematic diagram of the cooling air control loop system in an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal provided in Embodiment 1 of the present invention. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] This embodiment proposes an intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal. The system includes a fuel control loop system, a combustion air control loop system, and a cooling air control loop system.

[0027] like Figure 1 As shown, the fuel control loop system includes a simulated energy balance control module and a working condition identification module. The simulated energy balance control module is used to calculate the total required heat as the set value, calculate the actual total heat as the measured value, and adjust the opening of the controlled object based on the current working condition identification result. When the current working condition identification result is blended combustion, the pulverized coal controller is invoked to adjust the opening of the pulverized coal metering screw of the pulverized coal feeder. When the current working condition identification result is single combustion, the gas controller is invoked to adjust the opening of the gas regulating valve of the gas feeder. The working condition identification module is used to identify the current working condition and determine whether it is blended combustion or single combustion.

[0028] like Figure 2 As shown, the combustion air control loop system is used to adjust the frequency converter of the combustion air supply by comparing the set value and the actual value of the oxygen content, so as to keep the actual value of the oxygen content of the combustion air near the set value. The set value of the oxygen content is found by the oxygen content self-optimization function to find the oxygen content that meets the optimal combustion conditions.

[0029] like Figure 4 As shown, the cooling air control loop system is used to take the upper limit of the ash discharge temperature and the upper limit of the lower suction beam temperature as dual control targets, and the real-time ash discharge output as feedforward to adjust the frequency conversion opening of the cooling fan to ensure that the ash discharge temperature and the lower suction beam temperature do not exceed the limit.

[0030] The specific implementation process is as follows:

[0031] 1. Fuel control circuit:

[0032] The fuel control loop controls the pulverized coal metering screw regulator and the gas valve regulator, and the control conditions include single combustion and blended combustion. Single combustion refers to burning only the mixed gas from the blast furnace and converter, while blended combustion refers to burning pulverized coal in the mixed gas.

[0033] Dual-condition multi-objective coordinated control: Both operating conditions employ a simulated energy balance control module as the main controller, using the calculated total heat demand as the setpoint and the calculated actual total heat demand as the measured value to control the target. Kiln temperature is used as the auxiliary control objective to correct the calculated total heat demand in real time. During single-fired operation, the simulated energy balance control module controls the gas regulating valve; additionally, the safe gas pressure limit restricts the valve's operating range. During blended firing, the simulated energy balance control module controls the upper and lower metering screws for pulverized coal feeding; the safe gas pressure limit is the primary control objective for controlling the gas regulating valve.

[0034] The circuit employs a combined main and auxiliary control method. The main control module is a simulated energy balance control module, which uses the calculated total heat demand as the setpoint and the calculated actual total heat as the measured value to adjust the opening of the controlled object. The auxiliary control module is a kiln temperature correction model, which corrects the calculated total heat demand based on the kiln temperature. Based on the identification results of the operating condition identification module, during co-firing, the pulverized coal controller is activated as the controller for the simulated energy balance control module, outputting the opening of the upper and lower layer metering screws; during single-firing, the gas controller is activated as the controller for the simulated energy balance control module, outputting the opening of the gas regulating valve. In both single-firing and dual-firing conditions, the gas pressure limiting control module participates in the gas regulating valve control to ensure the safety of lime kiln production.

[0035] (1) Product qualification heat demand prediction model: Based on the analysis data of ash products, the model calculates the average heat Q_AVG required to produce one ton of lime that meets the qualification standard and the lime kiln ash discharge flow rate FT_CH. Based on these two data, the model calculates the total heat demand Q_SP1=Q_AVG*FT_CH.

[0036] (2) Kiln temperature correction model: PID control algorithm and soft servo control algorithm are adopted. The setpoint of the kiln temperature is set to TYN_SP, the measured value of the kiln temperature after processing is set to TYN_PV, and the output of the module is the correction value Q_SP2 for calculating the total heat demand.

[0037] (3) Soft measurement model for pulverized coal flow: Based on the weight of the pulverized coal silo, the soft measurement value of pulverized coal flow, FMF_RCL1, is calculated using a linear regression algorithm.

[0038] (4) Pulverized Coal Flow Rate Selection and Processing Module: Using the metering screw opening HZ_JL and the average pulverized coal flow rate per unit opening FMF_JLAVG, we obtain FMF_RCL2 = HZ_JL * FMF_JLAVG. When replenishing pulverized coal in the pulverized coal silo, the soft-measured value of pulverized coal flow rate FMF_RCL = FMF_RCL2; otherwise, FMF_RCL = FMF_RCL1. Based on manual selection, the pulverized coal flow rate FT_MF is represented by either the soft-measured value FMF_RCL or the actual measured value FMF_SJ.

[0039] (5) Simulated energy balance control module: The calorific value of blast furnace gas is RZ_GL, the flow rate of blast furnace gas is FT_GL, the calorific value of converter gas is RZ_ZL, the flow rate of converter gas is FT_ZL, the flow rate of mixed gas is FT_RQ, the calorific value of pulverized coal is RZ_MF, the actual total heat Q_PV is calculated as FT_RQ*(RZ_GL*FT_GL / (FT_GL+FT_ZL)+RZ_GL*FT_GL / (FT_GL+FT_ZL))+FTMF*RZ_MF, the set value of the simulated energy balance control module is Q_SP=Q_SP1+Q_SP2, and the measured value is used to calculate the actual total heat Q_PV.

[0040] (6) Pulverized coal controller: This module adopts PID control algorithm and soft servo control algorithm. The set value is Q_SP, the measured value is Q_PV, and the output value is Q_AV, which is the opening degree of the upper and lower layer metering screws HZ_AV.

[0041] (7) Gas controller: This module adopts PID control algorithm and soft servo control algorithm. The set value is Q_SP, the measured value is Q_PV, and the output value is Q_AV, which is the opening degree of the gas regulating valve FRQ_AV1.

[0042] (8) Gas Pressure Limiting Control Module: This module employs PID control and soft servo control algorithms. The measured value is the pressure after the fast-cut valve (after the gas regulating valve). The setpoint P_SP tracks the measured value P_PV when the gas pressure is within the limit, and becomes the gas pressure limit when the gas pressure exceeds the limit. The controller output is FRQ_AV2. The gas regulating valve opening FRQ_AV = FRQ_AV1 + FRQ_AV2. In the non-tracking range of the gas pressure limiting control module, when the gas pressure exceeds the upper limit, it outputs a prohibition signal to the gas controller to increase the pressure; when the gas pressure exceeds the lower limit, it outputs a prohibition signal to the gas controller to decrease the pressure.

[0043] In this embodiment, both the coal powder metering screw and the gas regulating valve opening control are deviation control, that is, the controller or module outputs the deviation value, and the actual opening value is the opening when switching to automatic plus the sum of the output deviation value.

[0044] (9) Operating condition identifier: Based on signals such as the switch status of the pulverized coal pipeline shut-off valve, the output status of the metering screw, and the status of the gas pipeline shut-off valve, it automatically determines whether the current operating condition is single combustion or mixed combustion, and outputs the operating condition signal.

[0045] In this embodiment, the fuel control loop employs dual-condition multi-objective coordinated control. Both conditions utilize a simulated energy balance control module to calculate the total heat required for qualified ash discharge and the total heat of fuel entering the furnace. Based on the energy balance, the calculated total heat requirement is used as the setpoint, and the actual total heat is used as the measured value to control the target. Kiln temperature is used as an auxiliary control target to correct the calculated total heat requirement in real time. When only blast furnace and converter mixed gas is burned, the simulated energy balance control module controls the gas regulating valve; on the other hand, the safe production gas pressure limit restricts the operating range of the gas regulating valve. When mixed gas is co-fired with pulverized coal, the simulated energy balance control module controls the upper and lower metering screws of the pulverized coal feed; the safe production gas pressure limit is used as the primary control target to control the gas regulating valve. Depending on the operating conditions, an operating condition identifier is used to automatically switch control schemes, and a simulated energy balance algorithm is added, supplemented by a kiln temperature correction model, to select the controlled object for control. The simulated energy balance is based on the analysis data of the ash products and the ash output data to simulate and calculate the heat required to produce qualified products. Then, based on the calorific value of the mixed gas, the flow rate of the mixed gas, the flow rate of pulverized coal, and the calorific value of pulverized coal, the heat of the fuel currently entering the kiln is calculated. The two are balanced to burn the furnace, overcome the problem of slow temperature response in the kiln, achieve the purpose of responding to changes in the ash output of the lime kiln in advance, and stabilize the ash output quality.

[0046] 2. Combustion Air Control Loop: By comparing the setpoint and actual oxygen content, the air supply frequency converter is adjusted to maintain the actual oxygen content near the setpoint. The setpoint oxygen content utilizes an oxygen content self-optimization function to find the oxygen content that satisfies optimal combustion conditions, improving combustion efficiency and achieving energy savings. The oxygen content regulator adjusts the air supply frequency converter opening based on the deviation between the actual value measured by the oxygen content optimization controller and the oxygen content measuring instrument. The output of the oxygen content optimization controller is the setpoint oxygen content. The output of the actual total heat correction feedforward, together with the oxygen content regulator, adjusts the combustion air opening.

[0047] The oxygen content self-optimization function means that the manually set oxygen content setting value is not necessarily the oxygen content required for the best combustion effect. The oxygen content self-optimization function finds the oxygen content setting value that best fits the current operating conditions, thereby improving combustion efficiency and achieving energy saving and consumption reduction.

[0048] (1) Oxygen content regulator: This module adopts a soft servo control algorithm. The oxygen content setpoint is O2_SP, the measured value is O2_PV, and the output of the module is O2_AV.

[0049] (2) Oxygen content optimization controller, automatic optimization process as follows: Figure 3 As shown:

[0050] First, set the optimization step size SOP = ΔF. A =γ*F A(γ ranges from 1% to 2%), where F A The current oxygen content control point has an allowable error ε, which ranges from 1 to 2, and the counter n = 0.

[0051] ① After setting the controller's running flag to ON, record an optimization objective function value J1 after 1-2 minutes;

[0052] ② Select to increase oxygen content control point, set n = n + 1, the oxygen content setpoint increment is the set step size n * SOP, output the oxygen content setpoint to the oxygen content controller; modify the current oxygen content, and go to step ⑧;

[0053] ③ If J2 > J1, the search direction is correct; continue searching in this direction, assign the value of J2 to J1, and proceed to step ②. If J2 < J1, determine if this is the first optimization attempt (i.e., n = 1). If n = 1, the search direction is incorrect; proceed to step ④. If n ≠ 1 and |J2 - J1| < ε, the current oxygen content is optimal; the current optimization ends, and the optimization controller's running flag is set to OFF. If n ≠ 1 and |J2 - J1| > ε, the variable step size search is set to SOP = -0.25 * SOP, and proceed to step ②.

[0054] ④ Select to increase oxygen content, set n = n + 1, the oxygen content setpoint increment is the set step size n * (-SOP), output the oxygen content setpoint to the oxygen content controller; modify the current oxygen content, and go to step ⑧;

[0055] ⑤ If J2 > J1, it means the search direction is correct. Continue searching in that direction, assign the value of J2 to J1, and go to step ④.

[0056] ⑥ If J2 < J1 and |J2 - J1| < ε, then the current oxygen content is in the optimal state, the optimization process ends, and the optimization controller's running flag is set to OFF.

[0057] ⑦ If J2 < J1 and |J2-J1| > ε, then use the variable step size to find SOP = -0.25*SOP and proceed to step ②.

[0058] ⑧ Calculation of the objective function value: Using the steady-state real-time process measurement values ​​after dynamic response, calculate the objective function value J2 according to the optimized objective function. That is, the calculation begins some time after the optimized output is applied to the device; the time depends on the dynamic response time of the process, generally taken as 2-3 minutes. Return to the original position.

[0059] The actual total heat calculation correction feedforward: The actual total heat calculation setpoint Q_SP2 is the current actual total heat calculation Q_PV2 recorded when just switched to automatic. The output of this feedforward is Q_AV2=K1*(Q_PV2-Q_SP2). Where K1=0.002;

[0060] 3. Cooling air control loop: This loop consists of three parts: the upper limit controller for ash discharge temperature, the upper limit controller for the lower suction beam temperature, and the feedforward for ash discharge production correction. The sum of these three parts is the total output of the loop, which controls the frequency conversion opening of the cooling fan.

[0061] (1) Ash discharge temperature upper limit controller: This module adopts PID control algorithm and soft servo control algorithm. The measured value is the ash discharge temperature TCH_PV. The set value TCH_SP tracks the measured value when the ash discharge temperature does not exceed the limit. When the ash discharge temperature exceeds the limit, it is the upper limit value of the ash discharge temperature TCH_HSP. The output is the frequency conversion opening degree of the cooling fan TCH_AV.

[0062] (2) Lower intake beam temperature upper limit controller: This module adopts PID control algorithm and soft servo control algorithm. The measured value is the lower intake beam temperature TXQL_PV. The set value TXQL_SP tracks the measured value when the lower intake beam temperature does not exceed the limit. When the lower intake beam temperature exceeds the limit, it is the lower intake beam temperature upper limit value TXQL_HSP. The output is the cooling fan frequency conversion opening TXQL_AV.

[0063] (3) Ash output correction feedforward: The ash output setpoint CH_SP is the current ash output CH_PV recorded when it is just switched to automatic. The output of this feedforward is CH_AV=K2*(CH_PV-CH_SP). Where K2=1.2.

[0064] The three control loops work together to achieve intelligent combustion optimization control of the double-beam lime kiln with pulverized coal.

[0065] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A smart combustion optimization control system for a double-beam lime kiln with pulverized coal, characterized in that, The system includes a fuel control loop system, a combustion air control loop system, and a cooling air control loop system. The fuel control loop system includes a simulated energy balance control module and a working condition identification module. The simulated energy balance control module is used to calculate the total required heat as a set value and the actual total heat as a measured value. It dynamically balances the furnace operation based on the set value and the measured value, and adjusts the opening of the controlled object in conjunction with the current working condition identification result. When the current working condition identification result is blended combustion, it calls the pulverized coal controller to adjust the opening of the pulverized coal metering screw for pulverized coal feeding. When the current working condition identification result is single combustion, it calls the gas controller to adjust the opening of the gas regulating valve for gas feeding. The working condition identification module is used to identify the current working condition and determine whether it is blended combustion or single combustion. The combustion air control loop system is used to adjust the frequency converter of the combustion air supply by comparing the set value and the actual value of the oxygen content, so as to keep the actual value of the oxygen content of the combustion air near the set value. The set value of the oxygen content is found by the oxygen content self-optimization function to find the oxygen content that meets the optimal combustion conditions. The cooling air control loop system is used to take the upper limit of ash discharge temperature and the upper limit of lower suction beam temperature as dual control targets, and the real-time ash discharge output as feedforward to adjust the frequency conversion opening of the cooling fan to ensure that the ash discharge temperature and the lower suction beam temperature do not exceed the limit. The fuel control loop system also includes a product qualification heat demand prediction model. The product qualification heat demand prediction model is used to calculate the average heat Q_AVG and lime kiln ash discharge flow rate FT_CH required to produce one ton of lime that meets the qualification standard based on the ash product analysis data. Based on these two data, the total heat demand Q_SP1 = Q_AVG * FT_CH is obtained. The fuel control loop system also includes a kiln temperature correction model, which is used to use the kiln temperature as an auxiliary control target to correct and calculate the total heat demand in real time. The cooling air control loop system includes an upper limit controller for ash discharge temperature, an upper limit controller for the lower suction beam temperature, and a feedforward controller for ash discharge output correction. The sum of these three is the total loop output, which controls the frequency conversion opening of the cooling fan. The measured value of the upper limit controller for ash discharge temperature is ash discharge temperature TCH_PV. The setpoint TCH_SP tracks the measured value when the ash discharge temperature does not exceed the limit, and becomes the upper limit value TCH_HSP when the ash discharge temperature exceeds the limit. The output is the frequency conversion opening of the cooling fan TCH_AV. The upper limit controller for the lower suction beam temperature... The controller measures the temperature of the lower suction beam (TXQL_PV). The setpoint (TXQL_SP) tracks the measured value when the temperature of the lower suction beam is within the limit, and sets it to the upper limit value (TXQL_HSP) when the temperature exceeds the limit. The output is the frequency conversion opening degree of the cooling fan (TXQL_AV). The ash output setpoint (CH_SP) is the current ash output (CH_PV) recorded when the system is switched to automatic mode. The output of this feedforward is CH_AV = K2 * (CH_PV - CH_SP), where K2 is the setpoint.

2. The intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal as described in claim 1, characterized in that, The fuel control loop system also includes a gas pressure limiting control module, which participates in the control of the gas regulating valve under both single-burning and blending conditions. When the gas pressure exceeds the upper limit, it outputs a prohibition signal to the gas controller; when the gas pressure exceeds the lower limit, it outputs a prohibition signal to the gas controller.

3. The intelligent combustion optimization control system for a double-beam lime kiln with pulverized coal as described in claim 1, characterized in that, The combustion air control loop system includes an oxygen content optimization controller, an oxygen content regulator, and a feedforward for calculating actual total heat correction. The oxygen content optimization controller is used to automatically optimize and output an oxygen content setpoint based on a set optimization step size. The oxygen content regulator is used to adjust the frequency conversion opening of the air supply based on the deviation between the oxygen content setpoint output by the oxygen content optimization controller and the actual value measured by the oxygen content measuring instrument. The output of the feedforward for calculating actual total heat correction is used in conjunction with the oxygen content regulator to adjust the frequency conversion opening of the combustion air.

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