Exhaust gas recirculation control system based on emissions monitoring

Abstract

The application discloses a waste gas back blending combustion control system based on emission monitoring and belongs to the technical field of waste gas combustion control. Specifically, the application comprises a multi-source sensing detection module, a feedforward process control module, a feedback process control module, a back blending execution module and a monitoring and early warning module. The application synchronously monitors intake data and exhaust data, forms a feedforward-feedback compound control system, the feedforward control initially sets back blending waste gas flow and combustion air flow according to the intake data, the feedback control establishes a concentration-flow real-time model of nitrogen oxide and carbon monoxide according to the exhaust data, analyzes emission deviation based on the model, generates adjustment instructions for the back blending waste gas flow and the combustion air flow through a multivariable control algorithm, and obtains flow adjustment amplitudes responding to adjustment instructions of all levels by combining the emission deviation and the intake data, so that the back blending waste gas flow and the combustion air flow are coordinately adjusted, and the coordinated emission reduction of nitrogen oxide and carbon monoxide is realized.

Description

Technical Field

[0001] This invention relates to the field of coke oven exhaust gas combustion control technology, and more specifically, to an exhaust gas recycling and combustion control system based on emission monitoring. Background Technology

[0002] During coke oven production, the combustion temperature in the vertical flue can reach over 1800℃, resulting in a significantly higher amount of nitrogen oxides (NOx) generated in the flue gas. Some existing technologies use flue gas recirculation (FGR) to return some of the already burned flue gas to the combustion zone, thereby suppressing NOx generation by reducing the flame temperature and oxygen concentration.

[0003] For example, patent number CN113188141A discloses "A method for reducing nitrogen oxide emissions in coke oven flue gas". This patent involves drawing back some of the already burned flue gas through a high-temperature induced draft fan and adding the circulating flue gas into the combustion gas. The main purpose is to reduce the flame temperature and oxygen concentration to suppress NOx formation and thus reduce the amount of nitrogen oxides emitted.

[0004] Although the patent mentions monitoring nitrogen oxides (NOx) for waste gas recirculation, it simply starts and stops the recirculation after reaching a threshold, without considering changes in waste gas composition. This may lead to energy waste or unstable combustion. For example, excessive recirculation of inert flue gas (already-burned waste gas) can reduce flame temperature and suppress NOx, but it is very easy to cause incomplete combustion, resulting in excessive carbon monoxide (CO) emissions. Therefore, if only simple adjustments are made based on the NOx flow rate of the waste gas, it cannot cope with the dynamic fluctuations of waste gas composition, nor can it establish a synergistic control mechanism for carbon monoxide (CO) emissions.

[0005] In actual operation, when the calorific value of exhaust gas changes drastically or the remixing ratio is inappropriate, the following problems may occur: First, excessive remixing of inert flue gas may lead to incomplete combustion, resulting in excessive CO emissions; second, it is impossible to dynamically adapt to changes in exhaust gas composition, resulting in energy waste or unstable combustion; third, a single control target (only reducing NOx) may lead to pollution transfer, that is, NOx meets the standard but CO emissions deteriorate.

[0006] To address the aforementioned practical problems, we propose a waste gas recycling and combustion control system based on emission monitoring. Summary of the Invention

[0007] The purpose of this invention is to provide an exhaust gas recycling and combustion control system based on emission monitoring, so as to solve the technical defects mentioned in the background art.

[0008] The objective of this invention can be achieved through the following technical solution: an exhaust gas reprocessing and combustion control system based on emission monitoring, comprising a multi-source sensor detection module, a feedforward process control module, a feedback process control module, a reprocessing execution module, and a monitoring and early warning module;

[0009] The multi-source sensor detection module is used to acquire the intake data of the intake flue and the exhaust data of the exhaust flue, and transmit them to the feedforward process control module and the feedback process control module, respectively.

[0010] The feedforward process control module is used to receive intake air data, and to initially set the recirculation exhaust gas flow rate and combustion air flow rate through the feedforward control algorithm, and then send them to the recirculation execution module;

[0011] The feedback process control module is used to acquire exhaust data, including exhaust flow rate and concentration of emission components, including nitrogen oxides and carbon monoxide. Based on the exhaust flow rate and emission concentration, a concentration-flow rate real-time model is established and compared with the preset concentration-flow rate benchmark model to obtain the nitrogen oxide emission deviation and carbon monoxide emission deviation. Based on the multivariate control algorithm, different combinations of emission deviations are analyzed to generate multi-level adjustment commands. The flow rate adjustment range is obtained according to the deviation magnitude and intake data, and the adjustment commands and flow rate adjustment range are sent to the feedback execution module.

[0012] The re-distribution execution module responds to adjustment commands at all levels, adjusting the re-distribution exhaust gas flow rate and combustion air flow rate based on the initially set flow adjustment range, and sends the flow adjustment range and the emission deviation of the adjusted emission components to the monitoring and early warning module; the monitoring and early warning module generates multi-level early warning signals based on a comprehensive analysis of the flow adjustment range and emission deviation.

[0013] Furthermore, the initial setting process for the recirculated exhaust gas flow rate and the combustion air flow rate includes:

[0014] The feedforward process control module acquires intake air data, including the concentration and flow rate of combustible components, which include carbon monoxide, hydrogen, and oxygen. Based on the concentration and flow rate of combustible components, it calculates the intake calorific value of the current exhaust gas. This intake calorific value is the initial intake calorific value. Based on the initial intake calorific value, it sets the baseline for the recirculated exhaust gas flow rate and the combustion air flow rate.

[0015] Furthermore, the process for obtaining the nitrogen oxide emission deviation and carbon monoxide emission deviation includes:

[0016] A real-time concentration-flow model of nitrogen oxides and carbon monoxide was established based on exhaust flow rate and nitrogen oxide concentration.

[0017] By using a real-time nitrogen oxide concentration-flow rate model and a preset nitrogen oxide concentration-flow rate benchmark model, the real-time nitrogen oxide emission concentration and the benchmark predicted nitrogen oxide concentration corresponding to the same exhaust flow rate are obtained. The nitrogen oxide emission deviation is obtained by subtracting the two.

[0018] Similarly, by using the real-time carbon monoxide concentration-flow rate model and the preset carbon monoxide concentration-flow rate benchmark model, the real-time carbon monoxide emission concentration and the benchmark predicted carbon monoxide concentration corresponding to the same exhaust flow rate are obtained, and the carbon monoxide emission deviation is obtained by subtracting the two.

[0019] Furthermore, the adjustment instruction generation process includes:

[0020] When the deviation of nitrogen oxide emissions is greater than zero and the deviation of carbon monoxide emissions is less than or equal to zero, an upward adjustment command for the reprocessing exhaust gas and an upward adjustment command for the combustion air are generated.

[0021] When the carbon monoxide emission deviation is greater than zero, while the nitrogen oxide emission deviation is less than or equal to zero, it indicates that the carbon monoxide emission is too high and the nitrogen oxide emission is normal or too low, generating an upward adjustment command for combustion air and a downward adjustment command for recycled exhaust gas.

[0022] When the deviation of nitrogen oxide emissions is greater than zero and the deviation of carbon monoxide emissions is greater than zero, an upward adjustment command for combustion air is first generated. After the real-time carbon monoxide emission deviation is less than or equal to zero, an upward adjustment command for recirculation exhaust gas is then generated.

[0023] When the deviation of nitrogen oxide emissions is less than zero and the deviation of carbon monoxide emissions is less than zero, a downward adjustment command for the reprocessing exhaust gas and a downward adjustment command for the combustion air are generated.

[0024] Furthermore, the process of obtaining the adjustment range based on the magnitude of emission deviation and intake data includes:

[0025] Using nitrogen oxide emission deviation and intake air data as variable features of the reprocessing exhaust gas, and carbon monoxide emission deviation as correction feature of the reprocessing exhaust gas, the model for adjusting the reprocessing exhaust gas amplitude is input, and the adjustment amplitude of the reprocessing exhaust gas flow rate is output. Using carbon monoxide emission deviation and intake air data as variable features of the combustion air, and nitrogen oxide emission deviation as correction feature of the combustion air, the model for adjusting the combustion air amplitude is input, and the adjustment amplitude of the combustion air flow rate is output.

[0026] Furthermore, the process by which the reconfiguration execution module responds to adjustment instructions at all levels includes:

[0027] When responding to the upward adjustment command of the recirculation exhaust gas and the upward adjustment command of the combustion air, the adjustment range of the recirculation exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the upward adjustment flow rate based on the initially set recirculation exhaust gas flow rate and combustion air flow rate.

[0028] When responding to the command to adjust the combustion air upward and the command to adjust the return exhaust gas downward, the adjustment range of the return exhaust gas flow rate is taken as the downward adjustment flow rate based on the initially set return exhaust gas flow rate, and the adjustment range of the combustion air flow rate is taken as the upward adjustment flow rate based on the initially set combustion air flow rate.

[0029] When the combustion air upward adjustment command is responded to first, and then the return exhaust gas upward adjustment command is responded to later, the adjustment range of the combustion air flow rate is taken as the upward adjustment flow rate based on the initially set combustion air flow rate, and the adjustment range of the return exhaust gas flow rate is taken as the upward adjustment flow rate based on the initially set return exhaust gas flow rate.

[0030] When responding to the command to adjust the return exhaust gas flow rate downward and the command to adjust the combustion air flow rate downward, the adjustment range of the return exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the magnitude of the downward adjustment flow rate based on the initially set return exhaust gas flow rate and combustion air flow rate.

[0031] Furthermore, the monitoring and early warning module obtains the preset adjustment limit range, compares the flow adjustment range with the preset adjustment limit range, and generates a first-level early warning signal when the flow adjustment range reaches the maximum value of the preset adjustment limit range and either the nitrogen oxide emission deviation or the carbon monoxide emission deviation is still greater than zero. It also generates a second-level early warning signal when both the nitrogen oxide emission deviation and the carbon monoxide emission deviation are greater than zero.

[0032] Compared with the prior art, the advantages of this invention are:

[0033] 1. This solution involves the synchronous monitoring of intake and exhaust data, forming a feedforward-feedback composite control system. Specifically, based on real-time monitoring of intake data, the feedforward control algorithm is used to initially set the recirculation exhaust gas flow rate and combustion air flow rate. Then, a real-time concentration-flow model of nitrogen oxides and carbon monoxide is established based on exhaust data. Based on the model comparison and analysis, the magnitude and direction of emission deviations are analyzed. A multivariate control algorithm is used to generate adjustment commands at various levels for the recirculation exhaust gas flow rate and combustion air flow rate. The flow adjustment range in response to each adjustment command is obtained by combining the emission deviation and intake data. Based on the initial settings, the recirculation exhaust gas flow rate and combustion air flow rate are coordinated to achieve synergistic emission reduction of nitrogen oxides and carbon monoxide while ensuring combustion efficiency.

[0034] 2. Based on the above, the system achieves fine-tuning of the remixing strategy through component sensing, feedforward-feedback closed-loop control, and multi-variable adjustment. The core of the remixing strategy is to adjust the remixing exhaust gas flow rate, but it also takes into account the exhaust gas composition and combustion air. This not only ensures emission targets and combustion efficiency, but also promotes the effective utilization of combustible components in coke oven exhaust gas, thereby reducing greenhouse gas emissions and achieving multi-objective synergistic optimization of nitrogen oxide emission control, carbon monoxide emission control, combustion efficiency, and energy recovery. Attached Figure Description

[0035] Figure 1 This is a system principle block diagram of the present invention;

[0036] Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Example 1: This invention discloses a waste gas recycling and combustion control system based on emission monitoring. Please refer to [link / reference]. Figures 1-2 It includes a multi-source sensing detection module, a feedforward process control module, a feedback process control module, a reconfiguration execution module, and a monitoring and early warning module.

[0039] The multi-source sensing detection module is used to acquire the intake data of the intake flue and the exhaust data of the exhaust flue, and then transmits the intake data and exhaust data to the feedforward process control module and the feedback process control module, respectively.

[0040] The feedforward process control module receives intake air data, sets the initial flow rates of the re-distribution exhaust gas and combustion air through the feedforward control algorithm, and sends the initially set re-distribution exhaust gas and combustion air to the re-distribution execution module. The re-distribution execution module controls the re-distribution exhaust gas and combustion air based on the current intake air data.

[0041] The initial setting process for the recirculated exhaust gas flow rate and the combustion air flow rate includes:

[0042] The feedforward process control module acquires intake air data, including the concentration and flow rate of combustible components, which include carbon monoxide, hydrogen, and oxygen. Based on the concentration and flow rate of combustible components, it determines the intake calorific value of the current exhaust gas through a calorific value calculation model. This intake calorific value is the initial intake calorific value. The feedforward control algorithm specifically includes: setting a baseline remixed exhaust gas flow rate and combustion air flow rate based on the initial intake calorific value; determining the baseline remixing ratio based on a preset calorific value-remixing ratio mapping relationship according to the range of intake calorific value, i.e., obtaining the baseline remixed exhaust gas flow rate based on the baseline remixing ratio, the total exhaust gas flow rate, and the intake calorific value; simultaneously, calculating the theoretical air requirement based on the exhaust gas component concentration and the baseline remixed exhaust gas flow rate through a combustion chemistry metric model, and determining the baseline combustion air flow rate based on the calorific value range. The purpose of acquiring feedforward information is to obtain the chemical composition and calorific value of the intake air in real time, providing feedforward input for controlling the remixing flow rate and optimizing combustion.

[0043] Both the calorific value calculation model and the combustion stoichiometric model are deterministic mathematical models. The calorific value calculation model can be an empirical formula model or a linear weighted model, used to calculate the volumetric calorific value and total energy flow of the current exhaust gas based on the concentration of combustible components (carbon monoxide, hydrogen, etc.) monitored in real time in the intake flue and the total exhaust gas flow rate, providing a quantitative basis for setting the subsequent benchmark remixing ratio. The combustion stoichiometric model is a chemical reaction stoichiometric model, used to calculate the theoretical air requirement required for the complete combustion of combustible components based on the component concentration of the intake exhaust gas and the benchmark remixing exhaust gas flow rate, and to determine the final benchmark combustion air flow rate in combination with the calorific value range.

[0044] The feedback process control module is used to acquire exhaust data, including exhaust flow rate and the concentration of emission components, including nitrogen oxides and carbon monoxide. Based on the exhaust flow rate and emission concentration, a real-time concentration-flow rate model for the corresponding emission components is established. The deviation between the real-time concentration-flow rate model and a preset concentration-flow rate benchmark model is compared. The specific process includes:

[0045] A real-time nitrogen oxide concentration-flow rate model is established based on exhaust flow rate and nitrogen oxide concentration. A real-time carbon monoxide concentration-flow rate model is established based on exhaust flow rate and carbon monoxide concentration. The concentration-flow rate benchmark model represents the benchmark model established based on historical health data under ideal conditions, and the expected nitrogen oxide concentration and carbon monoxide concentration under the current flow rate under ideal conditions.

[0046] By using a real-time nitrogen oxide concentration-flow rate model and a preset nitrogen oxide concentration-flow rate benchmark model, the real-time nitrogen oxide emission concentration and the benchmark predicted nitrogen oxide concentration corresponding to the same exhaust flow rate are obtained. The nitrogen oxide emission deviation is obtained by subtracting the two.

[0047] Similarly, by using the real-time carbon monoxide concentration-flow rate model and the preset carbon monoxide concentration-flow rate benchmark model, the real-time carbon monoxide emission concentration and the benchmark carbon monoxide predicted concentration corresponding to the same exhaust flow rate are obtained, and the carbon monoxide emission deviation is obtained by subtracting the two.

[0048] Based on the analysis of the magnitude and direction of nitrogen oxide emission deviation and carbon monoxide emission deviation using a multivariable control algorithm, adjustment commands for the recirculation exhaust gas flow and combustion air flow are generated for different combinations of deviations. The flow adjustment range in response to each adjustment command is obtained based on the magnitude of the deviation and the intake data. The adjustment commands and flow adjustment range are then sent to the recirculation execution module.

[0049] The process of generating adjustment instructions for the recirculated exhaust gas flow rate and combustion air flow rate includes:

[0050] When the deviation of nitrogen oxide emissions is greater than zero and the deviation of carbon monoxide emissions is less than or equal to zero, it indicates that nitrogen oxide emissions are too high and carbon monoxide emissions are normal or too low. This generates an upward adjustment command for the return waste gas, increasing the flow rate of the return waste gas (to reduce combustion temperature and reduce NOx), and also generates an upward adjustment command for the combustion air. This is because increasing the return waste gas may cause incomplete combustion, so it is necessary to appropriately increase the combustion air.

[0051] When the carbon monoxide emission deviation is greater than zero, while the nitrogen oxide emission deviation is less than or equal to zero, it indicates that the carbon monoxide emission is too high and the nitrogen oxide emission is normal or too low. This generates an upward adjustment command for the combustion air, increasing the combustion air flow (to promote combustion and reduce CO), and a downward adjustment command for the return exhaust gas. This is because increasing the air flow may increase NOx, so the return exhaust gas flow can be appropriately reduced to suppress NOx generation.

[0052] When both nitrogen oxide (NOx) and carbon monoxide (CO) emission deviations are greater than zero, it indicates that both emissions are too high. An upward adjustment command for combustion air is first generated. Once the real-time CO emission deviation is less than or equal to zero, an upward adjustment command for recirculated exhaust gas is generated. When both NOx and CO emission deviations are too high, this presents a contradictory situation that requires a trade-off. Typically, CO is prioritized to ensure it does not exceed the standard, as CO directly indicates incomplete combustion and is more harmful. Combustion air is increased first, and once CO begins to decrease, recirculated exhaust gas is then increased to reduce NOx.

[0053] When the deviation of nitrogen oxide emissions is less than zero and the deviation of carbon monoxide emissions is less than zero, it indicates that both emissions are too low. This generates a downward adjustment command for the return exhaust gas and the combustion air. The flow rates of the return exhaust gas and the combustion air can be appropriately reduced to save energy, but it is important to ensure that they are within safe limits.

[0054] The process of determining the adjustment range based on the magnitude of the deviation and the intake data includes:

[0055] Using nitrogen oxide emission deviation and intake air data as variable features of the reprocessing exhaust gas, and carbon monoxide emission deviation as a correction feature of the reprocessing exhaust gas, the model for adjusting the reprocessing exhaust gas amplitude is input, and the model for adjusting the reprocessing exhaust gas flow rate is output. The model for adjusting the reprocessing exhaust gas amplitude mainly responds to nitrogen oxide deviation, while also considering carbon monoxide constraints and intake conditions. Using carbon monoxide emission deviation and intake air data as variable features of the combustion air, and nitrogen oxide emission deviation as a correction feature of the combustion air, the model for adjusting the combustion air amplitude is input, and the model for adjusting the combustion air flow rate is output. The model for adjusting the combustion air amplitude mainly responds to carbon monoxide deviation, while also evaluating the coupling effect on nitrogen oxides.

[0056] The recirculation exhaust gas amplitude regulation machine model is a data-driven nonlinear mapping model. Its main function is to dynamically calculate the adjustment amplitude of the recirculation exhaust gas flow rate, using NOx emission deviation as the primary driving signal while incorporating carbon monoxide (CO) emission constraints and intake air condition characteristics. This model establishes a nonlinear mapping relationship between input features and output adjustment amplitude through offline training or online learning. The combustion air amplitude regulation machine model is an intelligent regulation model that uses CO emission deviation as the primary driving signal and simultaneously evaluates the coupling effect on NOx. Its function is to dynamically calculate the adjustment amplitude of the combustion air flow rate to prioritize complete CO combustion while avoiding drastic NOx fluctuations. This model can also be trained using supervised learning algorithms. To improve engineering reliability, a regional linear model or an expert rule-based fuzzy inference system is typically used as the initial version, gradually transitioning to a data-driven model.

[0057] The feedback process control module sends the adjustment instructions at each level and the corresponding flow adjustment range obtained from the adjustment instructions at each level to the reconfiguration execution module;

[0058] The recirculation execution module responds to adjustment commands at all levels, adjusting the recirculation exhaust gas flow rate and combustion air flow rate based on the initially set flow adjustment range. The specific process includes:

[0059] When responding to the upward adjustment command of the recirculation exhaust gas and the upward adjustment command of the combustion air, the adjustment range of the recirculation exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the upward adjustment flow rate based on the initially set recirculation exhaust gas flow rate and combustion air flow rate.

[0060] When responding to the command to adjust the combustion air upward and the command to adjust the return exhaust gas downward, the adjustment range of the return exhaust gas flow rate is taken as the downward adjustment flow rate based on the initially set return exhaust gas flow rate, and the adjustment range of the combustion air flow rate is taken as the upward adjustment flow rate based on the initially set combustion air flow rate.

[0061] When responding first to the command to adjust the combustion air upward and then to the command to adjust the return exhaust gas upward, the adjustment range of the combustion air flow rate and the adjustment range of the return exhaust gas flow rate are used as the magnitude of the upward adjustment based on the initially set combustion air flow rate and return exhaust gas flow rate.

[0062] When responding to the command to adjust the return exhaust gas flow rate downward and the command to adjust the combustion air flow rate downward, the adjustment range of the return exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the magnitude of the downward adjustment flow rate based on the initially set return exhaust gas flow rate and combustion air flow rate.

[0063] Combustible components in exhaust gas (such as CO and CH4) are themselves potent greenhouse gases or incomplete combustion products. Direct emission is equivalent to releasing these greenhouse gases directly into the atmosphere without any utilization, resulting in persistently high total carbon emissions from enterprises. Based on emissions data deviation analysis, a multivariate control algorithm is used to generate back-matching exhaust gas flow adjustment instructions and combustion air flow adjustment instructions. Through intelligent back-matching technology, the combustible components in coke oven exhaust gas will be effectively utilized, thereby reducing greenhouse gas emissions.

[0064] The reconfiguration execution module sends the flow rate adjustment range and the emission deviation of the adjusted emission components to the monitoring and early warning module;

[0065] The monitoring and early warning module generates multi-level early warning signals based on a comprehensive analysis of the emission deviations of the adjusted emission components and the magnitude of the flow rate adjustment. The specific process includes:

[0066] The monitoring and early warning module acquires the preset adjustment limit range and receives the flow adjustment range, as well as the nitrogen oxide emission deviation and carbon monoxide emission deviation after adjustment based on the flow adjustment range.

[0067] The flow rate adjustment range is compared with the preset adjustment limit range. When the flow rate adjustment range reaches the maximum value of the preset adjustment limit range, a first-level warning signal is generated if either the nitrogen oxide emission deviation or the carbon monoxide emission deviation is still greater than zero. A second-level warning signal is generated if both the nitrogen oxide emission deviation and the carbon monoxide emission deviation are greater than zero.

[0068] In summary, the synchronous monitoring of intake and exhaust data constitutes a feedforward-feedback composite control system. Specifically, based on real-time monitoring of intake data, the feedforward control algorithm is used to initially set the recirculation exhaust gas flow rate and combustion air flow rate. Then, a real-time concentration-flow model of nitrogen oxides and carbon monoxide is established based on exhaust data. The magnitude and direction of emission deviation are analyzed by comparing the real-time concentration-flow model with the preset concentration-flow benchmark model. A multivariate control algorithm is used to generate adjustment commands at various levels for the recirculation exhaust gas flow rate and combustion air flow rate. The flow adjustment range in response to each adjustment command is obtained by combining the emission deviation and intake data. Based on the initial settings, the recirculation exhaust gas flow rate and combustion air flow rate are synergistically adjusted to achieve synergistic emission reduction of nitrogen oxides and carbon monoxide.

[0069] The system achieves fine-tuning of the remixing strategy through component sensing, feedforward-feedback closed-loop control, and multi-variable adjustment. The core of the remixing strategy is to adjust the remixing exhaust gas flow rate, but it also takes into account the exhaust gas composition and combustion air. This not only ensures emission targets and combustion efficiency, but also promotes the effective utilization of combustible components in coke oven exhaust gas, thereby reducing greenhouse gas emissions and achieving multi-objective synergistic optimization of nitrogen oxide emission control, carbon monoxide emission control, combustion efficiency, and energy recovery.

[0070] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto; any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A waste gas recycling and combustion control system based on emission monitoring, characterized in that: It includes a multi-source sensing detection module, a feedforward process control module, a feedback process control module, a reconfiguration execution module, and a monitoring and early warning module; The multi-source sensor detection module is used to acquire the intake data of the intake flue and the exhaust data of the exhaust flue, and transmit them to the feedforward process control module and the feedback process control module, respectively. The feedforward process control module is used to receive intake air data, and to initially set the recirculation exhaust gas flow rate and combustion air flow rate through the feedforward control algorithm, and then send them to the recirculation execution module; The feedback process control module is used to acquire exhaust data, including exhaust flow rate and the concentration of emission components, including nitrogen oxides and carbon monoxide. Based on the exhaust flow rate and emission concentration, a concentration-flow rate real-time model is established and the deviation is compared with the preset concentration-flow rate benchmark model to obtain the nitrogen oxide emission deviation and carbon monoxide emission deviation. Based on the multivariate control algorithm, different combinations of emission deviations are analyzed to generate multi-level adjustment commands. The flow rate adjustment range is obtained according to the magnitude of the emission deviation and the intake data. The adjustment commands and flow rate adjustment range are sent to the feedback execution module. The remixing execution module responds to adjustment commands at all levels, and adjusts the remixing exhaust gas flow rate and combustion air flow rate based on the flow adjustment range based on the initially set flow adjustment range, and sends the flow adjustment range and the emission deviation of the adjusted emission components to the monitoring and early warning module. The monitoring and early warning module generates multi-level early warning signals based on a comprehensive analysis of flow adjustment magnitude and emission deviation.

2. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 1, characterized in that: The initial setting process for the reprocessing exhaust gas flow rate and combustion air flow rate includes: The feedforward process control module acquires intake air data, including the concentration and flow rate of combustible components, which include carbon monoxide, hydrogen, and oxygen. Based on the concentration and flow rate of combustible components, it calculates the intake calorific value of the current exhaust gas. This intake calorific value is the initial intake calorific value. Based on the initial intake calorific value, it sets the baseline return exhaust gas flow rate and combustion air flow rate.

3. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 2, characterized in that: The process of obtaining the nitrogen oxide emission deviation and carbon monoxide emission deviation includes: A real-time concentration-flow model of nitrogen oxides and carbon monoxide was established based on exhaust flow rate and nitrogen oxide concentration. By using a real-time nitrogen oxide concentration-flow rate model and a preset nitrogen oxide concentration-flow rate benchmark model, the real-time nitrogen oxide emission concentration and the benchmark predicted nitrogen oxide concentration corresponding to the same exhaust flow rate are obtained. The nitrogen oxide emission deviation is obtained by subtracting the two. Similarly, by using the real-time carbon monoxide concentration-flow rate model and the preset carbon monoxide concentration-flow rate benchmark model, the real-time carbon monoxide emission concentration and the benchmark predicted carbon monoxide concentration corresponding to the same exhaust flow rate are obtained, and the carbon monoxide emission deviation is obtained by subtracting the two.

4. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 3, characterized in that: The adjustment instruction generation process includes: When the deviation of nitrogen oxide emissions is greater than zero and the deviation of carbon monoxide emissions is less than or equal to zero, an upward adjustment command for the reprocessing exhaust gas and an upward adjustment command for the combustion air are generated. When the carbon monoxide emission deviation is greater than zero, while the nitrogen oxide emission deviation is less than or equal to zero, it indicates that the carbon monoxide emission is too high and the nitrogen oxide emission is normal or too low, generating an upward adjustment command for combustion air and a downward adjustment command for recycled exhaust gas. When the deviation of nitrogen oxide emissions is greater than zero and the deviation of carbon monoxide emissions is greater than zero, an upward adjustment command for combustion air is first generated. After the real-time carbon monoxide emission deviation is less than or equal to zero, an upward adjustment command for recirculation exhaust gas is then generated. When the deviation of nitrogen oxide emissions is less than zero and the deviation of carbon monoxide emissions is less than zero, a downward adjustment command for the reprocessing exhaust gas and a downward adjustment command for the combustion air are generated.

5. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 4, characterized in that: The process of determining the adjustment range based on the magnitude of emission deviation and intake data includes: Using nitrogen oxide emission deviation and intake air data as variable features of the reprocessing exhaust gas, and carbon monoxide emission deviation as correction feature of the reprocessing exhaust gas, the model for adjusting the reprocessing exhaust gas amplitude is input, and the adjustment amplitude of the reprocessing exhaust gas flow rate is output. Using carbon monoxide emission deviation and intake air data as variable features of the combustion air, and nitrogen oxide emission deviation as correction feature of the combustion air, the model for adjusting the combustion air amplitude is input, and the adjustment amplitude of the combustion air flow rate is output.

6. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 5, characterized in that: The process by which the reconfiguration execution module responds to adjustment instructions at all levels includes: When responding to the upward adjustment command of the recirculation exhaust gas and the upward adjustment command of the combustion air, the adjustment range of the recirculation exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the upward adjustment flow rate based on the initially set recirculation exhaust gas flow rate and combustion air flow rate. When responding to the command to adjust the combustion air upward and the command to adjust the return exhaust gas downward, the adjustment range of the return exhaust gas flow rate is taken as the downward adjustment flow rate based on the initially set return exhaust gas flow rate, and the adjustment range of the combustion air flow rate is taken as the upward adjustment flow rate based on the initially set combustion air flow rate. When the combustion air upward adjustment command is responded to first, and then the return exhaust gas upward adjustment command is responded to later, the adjustment range of the combustion air flow rate is taken as the upward adjustment flow rate based on the initially set combustion air flow rate, and the adjustment range of the return exhaust gas flow rate is taken as the upward adjustment flow rate based on the initially set return exhaust gas flow rate. When responding to the command to adjust the return exhaust gas flow rate downward and the command to adjust the combustion air flow rate downward, the adjustment range of the return exhaust gas flow rate and the adjustment range of the combustion air flow rate are respectively used as the magnitude of the downward adjustment flow rate based on the initially set return exhaust gas flow rate and combustion air flow rate.

7. The exhaust gas recycling and combustion control system based on emission monitoring according to claim 6, characterized in that: The monitoring and early warning module obtains the preset adjustment limit range, compares the flow adjustment range with the preset adjustment limit range, and generates a first-level early warning signal when the flow adjustment range reaches the maximum value of the preset adjustment limit range and either the nitrogen oxide emission deviation or the carbon monoxide emission deviation is still greater than zero. It generates a second-level early warning signal when both the nitrogen oxide emission deviation and the carbon monoxide emission deviation are greater than zero.

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