Hydrogen-doped differential intelligent combustor combustion control system and method thereof

Abstract

The application discloses a hydrogen-doped differential intelligent combustor combustion control system and method, and relates to the technical field of combustor combustion control. The control system of the combustor is started, the combustor is checked to meet the ignition condition, the inner air passage is started to introduce the rotational flow air, the igniter is triggered, and the pilot ignition is completed; the outer air passage introduces the air, the hydrogen is introduced and differentially mixed, the main fuel is sprayed from the main fuel passage, the hydrogen is sprayed through the hydrogen passage, and the hydrogen spraying speed is lower than the air flow rate of the inner air passage and the outer air passage; the gas flow rate, the air pressure and the nitrogen oxide content of the exhaust gas in each passage are collected, the combustion model is established, the combustion model is deployed in the control system, the combustion model is used for prediction, and the optimal combustion control strategy is acquired. Based on the proposed combustion model, the hydrogen ratio doped in the combustor is adjusted, the hydrogen flow rate is controlled, the hydrogen and the main fuel are cooperatively combusted, and the combustion cost and the nitrogen oxide emission can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of burner combustion control technology, and in particular to a hydrogen-doped differential intelligent burner combustion control system and method. Background Technology

[0002] The burner of a suspension kiln continuously feeds fuel and air into the furnace, rationally organizes the fuel flow, and ensures good mixing, rapid and stable ignition and combustion. It is widely used in boilers, asphalt mixing plants, oil fields, incinerators, hot blast stoves, foundry machinery, and industrial kilns. Existing suspension kiln burners primarily use natural gas as fuel, providing heat to the suspension kiln through the combustion of a mixture of natural gas and air. However, relying solely on this mixture results in excessive nitrogen oxide emissions and resource waste. Therefore, current research focuses on adding hydrogen to the natural gas and air mixture to assist combustion, but control measures for hydrogen incorporation are lacking.

[0003] To address these issues, we designed a hydrogen-doped differential intelligent burner combustion control system and its method. Summary of the Invention

[0004] The purpose of this invention is to address the problem in the prior art where hydrogen is incorporated into the burner during combustion to assist combustion, but there is a lack of effective control measures for hydrogen incorporation. This invention proposes a hydrogen-incorporated differential intelligent burner combustion control system and method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A combustion control method for a hydrogen-doped differential intelligent burner includes the following steps:

[0007] Step 1: Start the power supply to the burner's control system, monitoring mechanism and actuator. After the control system checks that the burner meets the ignition conditions, it starts the purging procedure to purge the burner's gas path.

[0008] Step 2: Slowly open the ignition fuel supply channel, start the internal air channel, introduce swirling air, trigger the igniter, ignite the ignition fuel and air mixture, and complete the ignition;

[0009] Step 3: Start the external air duct to introduce air, introduce hydrogen and perform differential mixing, open the electric shut-off valve of the main fuel delivery, the main fuel is injected from the main fuel duct, open the electric shut-off valve of the hydrogen delivery, the hydrogen is injected through the hydrogen duct, and the hydrogen injection speed is lower than the air flow speed of the internal air duct and the external air duct.

[0010] Step 4: Collect gas flow rate and wind pressure in each channel, as well as the nitrogen oxide content in the exhaust gas. Use a flame monitoring device to monitor the flame morphology, establish a combustion model, and deploy the combustion model in the control system.

[0011] Step 5: The control system is set to automatically adjust the differential speed between hydrogen and air and the ratio of hydrogen in combustible gas, and uses the deployed combustion model to make predictions to obtain the optimal combustion control strategy.

[0012] Further preferred,

[0013] Step 1: The monitoring mechanism includes a temperature detector installed inside the furnace, a gas flow detector and a wind pressure sensor installed in each gas passage of the burner, a flame detector installed at the end of the burner, and a nitrogen oxide analyzer installed in the flue pipe of the furnace body for detecting exhaust gas; the actuator includes an electric shut-off valve installed in each gas passage and an ignition gun at the end of the burner.

[0014] The control system checks that the burner meets the ignition conditions, including: checking that the monitoring and actuators are in standby mode, that the pressure in each gas passage of fuel and air is within a safe range, and that there is no gas leakage;

[0015] Initiate the purging procedure to purge the gas passage of the burner: turn on the primary air fan to introduce inert gas into the burner and kiln head area at a certain air volume, and continue purging for a certain period of time to remove all combustible gases in the gas passage. After purging is completed, the control system prepares for ignition.

[0016] In a further preferred embodiment, step 2 involves slowly opening the ignition fuel supply channel, activating the internal air channel, introducing swirling air, triggering the igniter, and igniting the ignition fuel-air mixture to complete ignition.

[0017] The electric shut-off valve and flow controller of the ignition fuel supply channel are slowly opened by the control system. Ignition fuel is introduced into the ignition zone at the end of the burner according to the preset flow rate. At the same time, the internal air channel is activated to introduce swirling air to form a central recirculation zone at the end of the burner. The ignition gun at the end of the burner is activated to ignite the mixture of ignition fuel and air, thus completing the ignition operation.

[0018] The flame morphology is continuously monitored by a flame monitoring device to confirm that the ignition flame has been successfully established and is stable. Once the flame is confirmed to be stable, the control system locks the current flow rate of the ignition fuel and the internal air as the benchmark for stable operation.

[0019] In a further preferred embodiment, step 3 involves activating the external air duct to introduce air, which is then injected into the combustion zone inside the furnace in a swirling manner through the external air duct of the burner.

[0020] Hydrogen is introduced and differentially mixed. The electric shut-off valve for main fuel delivery is opened, and main fuel is injected from the main fuel channel in a swirling form according to load requirements. The electric shut-off valve for hydrogen delivery is opened, and hydrogen is injected from the hydrogen channel in a swirling form. The hydrogen injection speed is lower than the air flow speed in the inner and outer air channels, forming a shear layer to prevent hydrogen from directly and violently mixing with air, which could lead to backfire.

[0021] The thickness δ of the shear layer is expressed by the following formula:

[0022]

[0023] Δv=|v h -v l |

[0024] In the formula, μ represents the dynamic viscosity of the fluid, Re represents the Reynolds number based on velocity difference and shear layer thickness, ρ represents the fluid density, and v h V represents air velocity. l Indicates the hydrogen flow rate;

[0025] The control system adjusts the airflow and hydrogen flow rate through a flow controller. When the shear layer thickness reaches a certain critical value, the shear layer delamination becomes unstable, forming a turbulent mixing layer. Increasing the velocity difference accelerates the conversion of the shear layer into a turbulent mixing layer, promoting the mixing of fuel and air.

[0026] In a further preferred step, in step 4,

[0027] After ignition in step 2 and hydrogen mixing in step 3, the combustion process begins. Gas flow rate and pressure in each channel, as well as the nitrogen oxide content in the exhaust gas, are collected. The flame morphology is monitored using a flame monitoring mechanism. This includes: collecting gas flow rate and pressure data in each gas channel using gas flow detectors and pressure sensors installed in the burner; collecting nitrogen oxide content in the exhaust gas using a nitrogen oxide analyzer inside the furnace exhaust pipe; and extracting the flame length L from the flame morphology images collected by the flame monitoring mechanism. flame Maximum flame diameter D flame Brightness I in the core region of the flame core ;

[0028] A combustion model was established by collecting gas flow and wind pressure data, and monitoring flame morphology and nitrogen oxide content in the emitted gases. The process is as follows:

[0029]

[0030] In the formula, Q total This indicates the total calorific value input of the burner. This indicates the mass flow rate of hydrogen. Q represents the lower heating value of hydrogen.NG LHV represents the mass flow rate of the main fuel. NG Indicates the lower heating value of the main fuel; Indicates the proportion of hydrogen in the mixed gas;

[0031] The objective function is established using a multivariate nonlinear regression model:

[0032]

[0033] In the formula, F * Let N represent the optimal model function, and N represent the number of training samples. X ] i Let L(·) represent the true NOx value of the i-th sample, L(·) represent the loss function, Ω(F) represent the model complexity regularization term to prevent overfitting, and λ represent the regularization strength coefficient. i Let represent the input feature vector of the i-th sample.

[0034] Based on the objective function, a combustion model is constructed through iterative training:

[0035]

[0036] F M (x) represents the final combustion model after M iterations, F0 represents the initial predicted NOx value, m represents the number of iterations, and h m (x) represents the mapping of the training input x in the m-th round to a predicted value, γ. m This represents the weights for the m-th training round; the trained combustion model is then deployed in the control system.

[0037] In a further preferred embodiment, step 5 involves the control system automatically adjusting the differential speed between hydrogen and air, as well as the hydrogen ratio in the combustible gas, using the deployed combustion model F. M (x) Make predictions to obtain the optimal combustion control strategy, as follows:

[0038] The control system is set to adjust the differential velocity Δv between hydrogen and air, as well as the ratio of hydrogen in the combustible gas. Feature x new Input the deployed combustion model F M (x) is used for optimization prediction to obtain the predicted nitrogen oxide emissions [NO]. x ] pred , Evaluate different features x new [NO under combination] x ] pred Obtain the optimal combustion control strategy output by the combustion model: Output the optimal feature x at this point *new ,

[0039] A system applied to the aforementioned hydrogen-doped differential intelligent burner combustion control method, the control system comprising:

[0040] The monitoring system is used to monitor the burner's operating status in real time and obtain operating parameters;

[0041] An actuator is used to perform operations on the burner, including but not limited to ignition, opening and closing of the gas passage, and regulation of gas flow.

[0042] The gas passage, located on the burner delivery pipeline, is used to deliver the main fuel, hydrogen, and air into the furnace;

[0043] The combustion module, with a built-in combustion model and deployed within the control system, is used to adjust the differential speed between hydrogen and air, as well as the ratio of hydrogen in combustible gases, to optimize the combustion control strategy and achieve the lowest nitrogen oxide emissions.

[0044] More preferably, the monitoring mechanism includes a temperature detector, a gas flow detector, a wind pressure sensor, a flame detector, and a nitrogen oxide analyzer; the monitoring probe of the temperature detector is located inside the furnace, the gas flow detector and the wind pressure sensor are located in each gas passage of the burner, the flame detector is located at the end of the burner, and the nitrogen oxide analyzer is installed in the flue gas pipe of the furnace body;

[0045] The actuators include electrically operated shut-off valves installed on each gas passage and an ignition gun at the end of the burner.

[0046] More preferably, the gas passage includes: an external air passage, an internal air passage, a main fuel passage, and an ignition fuel passage. The main fuel passage is arranged between the external air passage and the internal air passage. The ignition fuel passage is arranged around the ignition gun at the end of the burner and is located inside the internal air passage. A confining air duct for transporting air is opened on the periphery of the external air passage.

[0047] More preferably, the probe of the flame detector protrudes from the end of the burner, and the probe is covered by a high-temperature resistant transparent cover; the ignition head of the ignition gun is symmetrically arranged on the other side of the flame detector with the midpoint of the end of the burner as the symmetrical point, and the tail end of the ignition gun is provided with a pull rod for operating the extension and retraction of the ignition gun.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows: By optimizing the air duct arrangement of the burner, the present invention delivers gas at different flow rates through each gas channel at different operating stages of the burner, creating a layered flow rate difference in the combustion zone corresponding to each gas channel, which can completely eliminate the risk of hydrogen backfire and deflagration; by collecting burner operating data and establishing a combustion model, and by inputting the hydrogen blending ratio and gas flow rate into the control system, the optimal operating parameters of the burner are obtained, ensuring maximum combustion of hydrogen and main fuel. It has a high degree of intelligence and flexible adjustment: it can adapt to different hydrogen blending ratios and heat load changes, which can effectively reduce combustion costs and nitrogen oxide emissions. Attached Figure Description

[0049] Figure 1 This is a schematic flowchart of a hydrogen-doped differential intelligent burner combustion control method proposed in this invention.

[0050] Figure 2 This is a logic diagram of a hydrogen-doped differential intelligent burner combustion control system proposed in this invention.

[0051] Figure 3 This is a schematic diagram of the overall structure of the burner in the combustion control system of a hydrogen-doped differential intelligent burner proposed in this invention.

[0052] Figure 4 This is a schematic diagram of the burner head structure in a hydrogen-doped differential intelligent burner combustion control system proposed in this invention.

[0053] The following are the labels in the diagram: 1, 2, external air passage; 3, internal air passage; 4, main fuel passage; 5, ignition fuel passage; 6, flame detector; 7, ignition gun; 71, pull rod; 8, constrained air passage. Detailed Implementation

[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0055] This embodiment proposes a combustion control method for a hydrogen-doped differential intelligent burner, which includes the following steps:

[0056] Step 1: Start the power supply to the burner's control system, monitoring mechanism and actuator. After the control system checks that the burner meets the ignition conditions, it starts the purging procedure to purge the burner's gas path.

[0057] The monitoring mechanism includes a temperature detector installed inside the furnace, a gas flow detector and a wind pressure sensor installed in each gas passage of the burner, a flame detector installed at the end of the burner, and a nitrogen oxide analyzer installed in the flue pipe of the furnace body for detecting exhaust gas; the actuator includes an electric shut-off valve installed in each gas passage and an ignition gun at the end of the burner.

[0058] The control system checks that the burner meets the ignition conditions, including: checking that the monitoring and actuators are in normal standby mode, that the pressure in each gas passage of fuel and air is within a safe range, and that there is no gas leakage;

[0059] Initiate the purging procedure to purge the burner's gas path: Turn on the primary air fan and introduce inert gas into the burner and kiln head area at a certain air volume (preferably a high air velocity). Continue purging for a certain period of time to remove all combustible gases from the gas path. After purging is complete, the control system prepares for ignition. The purpose of the above operations is to ensure the safety of burner start-up and ignition.

[0060] Step 2: Slowly open the ignition fuel supply channel, start the internal air channel, introduce swirling air, trigger the igniter, ignite the ignition fuel and air mixture, and complete the ignition;

[0061] The electric shut-off valve of the ignition fuel supply channel is slowly opened by the control system, and the flow controller is activated to slowly introduce ignition fuel into the ignition zone at the end of the burner according to the preset flow rate. Alternatively, an electric regulating valve can be added to the ignition fuel pipeline to facilitate flow rate control and slowly inject ignition fuel into the ignition zone, which helps to improve the ignition probability. At the same time, the internal air channel is activated to introduce swirling air to form a central recirculation zone at the end of the burner. Then, the ignition gun at the end of the burner is activated to ignite the mixture of ignition fuel and air, completing the ignition operation.

[0062] The flame morphology is continuously monitored by a flame monitoring device to confirm that the ignition flame has been successfully established and is stable. Once the flame is confirmed to be stable, the control system locks the current flow rate of the ignition fuel and the internal air as the benchmark for stable operation.

[0063] Step 3: Start the external air duct to introduce air, introduce hydrogen and perform differential mixing, open the electric shut-off valve of the main fuel delivery, the main fuel is injected from the main fuel duct, open the electric shut-off valve of the hydrogen delivery, the hydrogen is injected through the hydrogen duct, and the hydrogen injection speed is lower than the air flow speed of the internal air duct and the external air duct.

[0064] The external air duct is activated to introduce air, which is then injected into the combustion zone of the furnace in a swirling manner through the external air duct of the burner.

[0065] Hydrogen is introduced and differentially mixed. The electric shut-off valve for the main fuel supply is opened, and the main fuel is injected in a swirling pattern from the main fuel channel according to load requirements. The electric shut-off valve for the hydrogen supply is also opened, and hydrogen is injected in a swirling pattern through the hydrogen channel. The hydrogen injection velocity is lower than the air velocity in the inner and outer air channels, forming a shear layer to prevent direct and violent mixing of hydrogen and air, which could lead to backfire. In this step, the hydrogen is injected at a low speed, allowing the hydrogen plume to be ignited by the high-temperature flue gas and the already burning flame environment. The air velocity introduced into the outer air channel is much higher than the injection velocity of the hydrogen and main fuel. The high-speed outer air generates a strong entrainment effect, forcefully drawing the high-temperature secondary air in the furnace into the flame, achieving the final and complete mixing of fuel and oxygen; at the same time, the length and stiffness of the flame are controlled. The initial hydrogen introduction should not exceed 30% of the total hydrogen content, and then no more than the remaining 70% of the hydrogen should be introduced into the burner.

[0066] The thickness δ of the shear layer in this technical solution is expressed by the following formula:

[0067]

[0068] Δv=|v h -v l |

[0069] In the formula, μ represents the dynamic viscosity of the fluid, Re represents the Reynolds number based on the velocity difference and shear layer thickness, and ρ represents the fluid density. Considering the degree of influence, the parameter values ​​corresponding to the gas with the highest dynamic viscosity and density can be selected; v h V represents air velocity. l Indicates the hydrogen flow rate;

[0070] The control system regulates the air and hydrogen flow rates via a flow controller. This step involves secondary hydrogen regulation. When the shear layer thickness reaches a certain critical value, the shear layer destabilizes, forming a turbulent mixing layer. This critical value can be determined by observing changes in the flame morphology within the furnace using a flame detector. Increasing the velocity difference accelerates the transition from the shear layer to the turbulent mixing layer, promoting fuel-air mixing.

[0071] Step 4: Collect gas flow rate and air pressure in each channel, as well as the nitrogen oxide content in the emitted gas. Use a flame monitoring device to monitor the flame morphology, establish a combustion model, and deploy the combustion model in the control system; specifically, as follows:

[0072] After ignition in step 2 and hydrogen mixing in step 3, the burner enters a stable combustion state. Gas flow rate and pressure in each channel, as well as the nitrogen oxide content in the exhaust gas, are collected. The flame morphology is monitored using a flame monitoring mechanism. This includes: collecting gas flow rate and pressure in each gas channel using gas flow detectors and pressure sensors installed in the burner; collecting the nitrogen oxide content in the exhaust gas using a nitrogen oxide analyzer inside the furnace exhaust pipe; and extracting the flame length L from the flame morphology images collected by the flame monitoring mechanism. flame Maximum flame diameter D flame Brightness I in the core region of the flame core ;

[0073] A combustion model was established by collecting gas flow and wind pressure data, and monitoring flame morphology and nitrogen oxide content in the emitted gases. The process is as follows:

[0074]

[0075] In the formula, Q total This indicates the total calorific value input of the burner. This indicates the mass flow rate of hydrogen. Q represents the lower heating value of hydrogen. NG LHV represents the mass flow rate of the main fuel. NG Indicates the lower heating value of the main fuel; Indicates the proportion of hydrogen in the mixed gas;

[0076] The objective function is established using a multivariate nonlinear regression model:

[0077]

[0078] In the formula, F * Let N represent the optimal model function, and N represent the number of training samples. X ] i Let L(·) represent the true NOx value of the i-th sample, L(·) represent the loss function, Ω(F) represent the model complexity regularization term to prevent overfitting, and λ represent the regularization strength coefficient. i Let represent the input feature vector of the i-th sample.

[0079] A combustion model is constructed through iterative training based on an objective function and a gradient boosting tree.

[0080]

[0081] F M (x) represents the final combustion model after M iterations, F0 represents the initial predicted NOx value, m represents the number of iterations, and h m(x) represents the mapping of the training input x in the m-th round to a predicted value, γ. m This represents the weights for the m-th training round; the trained combustion model is then deployed in the control system.

[0082] The steps for each iteration are as follows:

[0083] For each sample i, calculate the negative gradient of the loss function with respect to the current model prediction:

[0084]

[0085] For squared loss, r im =[NO x ] i -F m-1 (x i ), using a new decision tree h m (x) to fit these negative gradients r im ;

[0086]

[0087] By finding the optimal step size γ m (Trained weights) to minimize the total loss:

[0088]

[0089] Therefore, the model is updated as follows:

[0090] F m (x)=F m-1 (x)+υ·γ m ·h m (x)

[0091] Here, υ is the learning rate, which is greater than zero and less than or equal to 1. It is used to control the magnitude of each iteration update and improve the generalization ability of the model.

[0092] Step 5: The control system is set to automatically adjust the differential speed between hydrogen and air and the ratio of hydrogen in the combustible gas. It uses the deployed combustion model to make predictions and obtain the optimal combustion control strategy. The process is as follows:

[0093] The control system is set to adjust the hydrogen-air differential velocity Δv and the hydrogen-to-combustible gas ratio R. H2 Feature x new Input the deployed combustion model F M (x) is used for optimization prediction to obtain the predicted nitrogen oxide emissions [NO]. x ] pred , Evaluate different features x new [NO under combination]x ] pred Obtain the optimal combustion control strategy output by the combustion model: Output the optimal feature x at this point * new ,

[0094] Based on the above technical solutions, this embodiment also proposes a system for combustion control of a hydrogen-doped differential intelligent burner, such as... Figure 2 As shown, the control system mainly includes: a monitoring mechanism, an actuator, a gas passage, and a combustion module.

[0095] The monitoring mechanism is used to monitor the operating status of burner 1 in real time and obtain operating parameters;

[0096] An actuator is used to perform operations including but not limited to ignition, opening and closing of gas passages, and regulation of gas flow.

[0097] The gas passage, located on the delivery pipeline of burner 1, is used to deliver the main fuel, hydrogen, and air into the furnace;

[0098] The combustion module, with a built-in combustion model and deployed within the control system, is used to adjust the differential speed between hydrogen and air, as well as the ratio of hydrogen in combustible gases, to optimize the combustion control strategy and achieve the lowest nitrogen oxide emissions.

[0099] The monitoring system includes temperature detectors, gas flow detectors, air pressure sensors, flame detectors, and nitrogen oxide analyzers. The temperature detector probes are located inside the furnace, but infrared thermometers can also be used. For more accurate temperature monitoring, it is best to install the temperature detector probes inside the furnace. Gas flow detectors and air pressure sensors, which measure the airflow velocity and pressure within each gas path, are installed in each gas path channel of burner 1 according to the different measurement targets.

[0100] Furthermore, the combustion control method for the hydrogen-doped differential intelligent burner proposed in this embodiment relies heavily on the unique design of each gas path channel within the burner. For example... Figure 3 and Figure 4As shown, the flame detector 6 is installed at the end of the burner 1, and the nitrogen oxide analyzer is installed inside the furnace exhaust pipe. The actuators include electric shut-off valves or regulating valves installed on each gas passage, and an ignition gun 7 at the end of the burner 1. Specifically, the gas passages include: an external air passage 2, an internal air passage 3, a main fuel passage 4, and an ignition fuel passage 5. The main fuel passage 4, which transports the main fuel, is located between the external air passage 2 and the internal air passage 3. The main fuel passage 4 surrounds the circular end of the burner and is arranged with multiple adjacent partitions, allowing the main fuel and hydrogen to be transported to the combustion zone separately at different flow rates. In this embodiment, the main fuel can be natural gas or coal gas, etc. The ignition fuel passage 5 is located around the ignition gun 7 at the end of the burner 1 and inside the internal air passage 3. The ignition fuel passage 5 slowly transports the ignition fuel to the ignition area, mixes it with the air transported by the internal air passage 3, and is ignited by the ignition gun 7. The internal air passage 3 and the ignition fuel passage 5 work together to establish a stable and reliable ignition source and flame anchoring zone. A confined air duct 8 is provided around the outer air duct 2 for transporting air. The air injected through the confined air duct 8 forms an air curtain barrier to prevent the leakage of air or fuel from the inside. The probe head of the flame detector 6 protrudes from the end of the burner 1 and is covered by a high-temperature resistant transparent cover. Thanks to the rapid development of aerospace technology, this high-temperature resistant transparent cover can be obtained on the market using existing technology. The ignition head of the ignition gun 7 is symmetrically positioned on the other side of the flame detector 6 with the midpoint of the end of the burner 1 as the symmetrical point. The tail end of the ignition gun 7 is provided with a pull rod 71 for operating the extension and retraction of the ignition gun 7. After the burner 1 is ignited, the ignition gun 7 is pulled out of the furnace by the actuator on one side of the pull rod 71, which prevents the ignition head from being exposed to high temperature for a long time, thus reducing its service life.

[0101] By using various gas passages in the burner, fuel and air are delivered to the combustion zone in multiple routes, by different areas, and at different times, which is beneficial for scheduling the delivery of each gas.

[0102] It should be noted that any parts not covered in this invention are the same as or can be implemented using existing technology. The above description is merely a preferred embodiment of this invention, but the scope of protection of this invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this invention, based on the technical solution and inventive concept of this invention, should be covered within the scope of protection of this invention.

Claims

1. A combustion control method for a hydrogen-doped differential intelligent burner, characterized in that, Includes the following steps: Step 1: Start the power supply to the burner's control system, monitoring mechanism and actuator. After the control system checks that the burner meets the ignition conditions, it starts the purging procedure to purge the burner's gas path. Step 2: Slowly open the ignition fuel supply channel, start the internal air channel, introduce swirling air, trigger the igniter, ignite the ignition fuel and air mixture, and complete the ignition; Step 3: Start the external air duct to introduce air, introduce hydrogen and perform differential mixing, open the electric shut-off valve of the main fuel delivery, the main fuel is injected from the main fuel duct, open the electric shut-off valve of the hydrogen delivery, the hydrogen is injected through the hydrogen duct, and the hydrogen injection speed is lower than the air flow speed of the internal air duct and the external air duct. Step 4: Collect gas flow rate and wind pressure in each channel, as well as the nitrogen oxide content in the exhaust gas. Use a flame monitoring device to monitor the flame morphology, establish a combustion model, and deploy the combustion model in the control system. Step 5: The control system is set to automatically adjust the differential speed between hydrogen and air and the ratio of hydrogen in combustible gas, and uses the deployed combustion model to make predictions to obtain the optimal combustion control strategy.

2. The combustion control method for a hydrogen-doped differential intelligent burner according to claim 1, characterized in that, Step 1: The monitoring mechanism includes a temperature detector installed inside the furnace, a gas flow detector and a wind pressure sensor installed in each gas passage of the burner, a flame detector installed at the end of the burner, and a nitrogen oxide analyzer installed in the flue pipe of the furnace body for detecting exhaust gas; the actuator includes an electric shut-off valve installed in each gas passage and an ignition gun at the end of the burner. The control system checks that the burner meets the ignition conditions, including: checking that the monitoring and actuators are in standby mode, that the pressure in each gas passage of fuel and air is within a safe range, and that there is no gas leakage; Initiate the purging procedure to purge the gas passage of the burner: turn on the primary air fan to introduce inert gas into the burner and kiln head area at a certain air volume, and continue purging for a certain period of time to remove all combustible gases in the gas passage. After purging is completed, the control system prepares for ignition.

3. The combustion control method for a hydrogen-doped differential intelligent burner according to claim 1, characterized in that, Step 2: Slowly open the ignition fuel supply channel, activate the internal air channel, introduce swirling air, trigger the igniter, and ignite the ignition fuel and air mixture to complete ignition. The electric shut-off valve and flow controller of the ignition fuel supply channel are slowly opened by the control system. Ignition fuel is introduced into the ignition zone at the end of the burner according to the preset flow rate. At the same time, the internal air channel is activated to introduce swirling air to form a central recirculation zone at the end of the burner. The ignition gun at the end of the burner is activated to ignite the mixture of ignition fuel and air, thus completing the ignition operation. The flame morphology is continuously monitored by a flame monitoring device to confirm that the ignition flame has been successfully established and is stable. Once the flame is confirmed to be stable, the control system locks the current flow rate of the ignition fuel and the internal air as the benchmark for stable operation.

4. The combustion control method for a hydrogen-doped differential intelligent burner according to claim 1, characterized in that, Step 3: Start the external air duct to introduce air. The air is injected into the combustion zone of the furnace in a swirling manner through the external air duct of the burner. Hydrogen is introduced and differentially mixed. The electric shut-off valve for main fuel delivery is opened, and main fuel is injected from the main fuel channel in a swirling form according to load requirements. The electric shut-off valve for hydrogen delivery is opened, and hydrogen is injected from the hydrogen channel in a swirling form. The hydrogen injection speed is lower than the air flow speed in the inner and outer air channels, forming a shear layer to prevent hydrogen from directly and violently mixing with air, which could lead to backfire. Shear layer thickness Expressed as follows: ， ， In the formula, Indicates the dynamic viscosity of a fluid. Represents the Reynolds number based on velocity difference and shear layer thickness. Indicates fluid density, Indicates air velocity. Indicates the hydrogen flow rate; The control system adjusts the airflow and hydrogen flow rate through a flow controller. When the shear layer thickness reaches a certain critical value, the shear layer delamination becomes unstable, forming a turbulent mixing layer. Increasing the velocity difference accelerates the conversion of the shear layer into a turbulent mixing layer, promoting the mixing of fuel and air.

5. The combustion control method for a hydrogen-doped differential intelligent burner according to claim 1, characterized in that, In step 4, After ignition in step 2 and hydrogen mixing in step 3, the combustion process begins. Gas flow rate and pressure in each channel, as well as the nitrogen oxide content in the exhaust gas, are collected. The flame morphology is monitored using a flame monitoring mechanism. This includes: collecting gas flow rate and pressure data through gas flow detectors and pressure sensors installed in each gas path of the burner; collecting nitrogen oxide content in the exhaust gas using a nitrogen oxide analyzer inside the furnace exhaust pipe; and extracting the flame length from the flame morphology images collected by the flame monitoring mechanism. Maximum diameter of flame Brightness of the core area of ​​the flame ; A combustion model was established by collecting gas flow and wind pressure data, and monitoring flame morphology and nitrogen oxide content in the emitted gases. The process is as follows: ， ， In the formula, This indicates the total calorific value input of the burner. This indicates the mass flow rate of hydrogen. This indicates the lower heating value of hydrogen. Indicates the mass flow rate of the main fuel. Indicates the lower heating value of the main fuel; Indicates the proportion of hydrogen in the mixed gas; The objective function is established using a multivariate nonlinear regression model: , In the formula, Let N represent the optimal model function, and N represent the number of training samples. Indicates the first The true NOx value of each sample Represents the loss function. This represents a model complexity regularization term to prevent overfitting. This represents the regularization strength coefficient. Indicates the first The input feature vector of each sample, ; Based on the objective function, a combustion model is constructed through iterative training: ， This represents the final combustion model after M iterations. This represents the initial predicted NOx value. Indicates the number of iteration rounds. Indicates the first Round training input Mapped to a predicted value, Indicates the first The weights of the training rounds are determined; the trained combustion model is then deployed in the control system.

6. The combustion control method for a hydrogen-doped differential intelligent burner according to claim 1, characterized in that, Step 5: The control system is set to automatically adjust the differential speed between hydrogen and air, as well as the ratio of hydrogen in the combustible gas, using the deployed combustion model. The process of making predictions and obtaining the optimal combustion control strategy is as follows: The control system is set to adjust the differential speed between hydrogen and air. and the ratio of hydrogen in combustible gas Features Input the deployed combustion model Optimized predictions were performed to obtain the predicted nitrogen oxide emissions. , ; Evaluate different characteristics Combination Obtain the optimal combustion control strategy output by the combustion model: Output the optimal feature at this point. , .

7. A system applied to the combustion control method of the hydrogen-doped differential intelligent burner according to claim 1, characterized in that, The control system includes: The monitoring system is used to monitor the burner's operating status in real time and obtain operating parameters; The actuator is used to perform operations on the burner, including ignition, opening and closing of the gas passage, and regulation of gas flow. The gas passage, located on the burner delivery pipeline, is used to deliver the main fuel, hydrogen, and air into the furnace; The combustion module, with a built-in combustion model and deployed within the control system, is used to adjust the differential speed between hydrogen and air, as well as the ratio of hydrogen in combustible gases, to optimize the combustion control strategy and achieve the lowest nitrogen oxide emissions.

8. The combustion control system for a hydrogen-doped differential intelligent burner according to claim 7, characterized in that, The monitoring mechanism includes a temperature detector, a gas flow detector, a wind pressure sensor, a flame detector, and a nitrogen oxide analyzer; the monitoring probe of the temperature detector is located inside the furnace, the gas flow detector and the wind pressure sensor are located in each gas passage of the burner, the flame detector is located at the end of the burner, and the nitrogen oxide analyzer is installed in the flue gas pipe of the furnace body. The actuators include electrically operated shut-off valves installed on each gas passage and an ignition gun at the end of the burner.

9. The combustion control system for a hydrogen-doped differential intelligent burner according to claim 8, characterized in that, The gas passage includes an external air passage, an internal air passage, a main fuel passage, and an ignition fuel passage. The main fuel passage is located between the external air passage and the internal air passage. The ignition fuel passage is located around the ignition gun at the end of the burner and inside the internal air passage. A confined air duct for transporting air is provided around the external air passage.

10. The combustion control system for a hydrogen-doped differential intelligent burner according to claim 9, characterized in that, The probe of the flame detector protrudes from the end of the burner and is covered by a high-temperature resistant transparent cover; the ignition head of the ignition gun is symmetrically positioned on the other side of the flame detector with the midpoint of the burner end as the ignition point, and the tail end of the ignition gun is provided with a pull rod for operating the extension and retraction of the ignition gun.

Images