Burner system based on EPR detection platform and control method thereof

Abstract

The invention provides a burner system based on an EPR detection platform and a control method of the burner system. Comprising a combustor; the air supply assembly is used for providing air for the combustor; the feeding assembly is used for providing fuel for the combustor; the extraction mechanism is used for extracting pyrolysis products from the combustor; the electron paramagnetic resonance detection platform is used for detecting the type and concentration of free radicals of the pyrolysis product by adopting electron paramagnetic resonance and determining the combustion state of the combustor; and the control unit is used for regulating and controlling the air quantity provided by the air supply system and the fuel quantity provided by the feeding system according to the combustion state of the combustor. Closed-loop control over the combustor can be achieved, and the combustion effect of the combustor is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of swirl burners, and in particular relates to a burner system based on an EPR detection platform and a control method thereof. Background Art

[0002] Electron paramagnetic resonance (EPR) detection technology, also known as electron spin resonance (ESR) detection, is an analytical method based on the principle of interaction between the electron spin magnetic moment and the external magnetic field. In EPR detection, when the unpaired electrons in the sample are exposed to an external magnetic field, the spin state of these electrons will split into two or more energy levels. By applying radio frequency radiation of a specific frequency, electrons can be induced to transition between these energy levels, thereby generating an EPR signal. The intensity of this signal is proportional to the number of unpaired electrons in the sample, so it can be used to quantitatively analyze free radicals or other substances with unpaired electrons in the sample. In the field of combustion engineering, EPR technology is used to detect free radicals and intermediates produced during the combustion process, which is of great significance for understanding the combustion mechanism, optimizing the combustion process, and reducing harmful emissions. At present, the EPR detection technology of burner tail products faces many challenges in practical applications. The traditional EPR detection method usually requires taking the sample out of the burner and transferring it to a special detection device. This process is not only time-consuming, but also may cause changes in the sample state, affecting the accuracy of the detection results. In addition, the operating conditions of the burner, such as changes in temperature, pressure and fuel type, will affect the composition and concentration of the combustion products, which requires the EPR detection method to adapt to these changes and provide real-time and accurate analysis results. In order to overcome these challenges, the present invention proposes an innovative burner tail extraction device and EPR detection platform, which can directly extract pyrolysis products inside the burner and perform fast and accurate EPR detection. This design not only improves the efficiency and accuracy of the detection, but also provides predictive data support for the flexible peak-shaving control of the burner by real-time monitoring of the combustion products, which helps to optimize the combustion process and improve energy efficiency. In view of this, it is necessary to design a burner pre-pyrolysis product sampling and EPR (electron paramagnetic resonance) detection method to achieve the above purpose. Summary of the invention

[0003] The present invention provides a burner system based on an EPR detection platform and a control method thereof, which can keep the burner in a good combustion state.

[0004] In one aspect, a burner system based on an EPR detection platform is provided, comprising: Burner; An air supply component, providing air for the burner; A feed assembly, which provides fuel to the burner; An extraction mechanism, used for extracting pyrolysis products from the burner; An electron paramagnetic resonance detection platform is used to detect the type and concentration of free radicals in pyrolysis products using electron paramagnetic resonance to determine the combustion state of the burner; The control unit is used to adjust the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state of the burner.

[0005] Optionally, the extraction mechanism includes: Sampling needle; A sampling tube, one end of which is connected to the sampling needle; An electric control valve is arranged between the sampling needle and the sampling tube; A vacuum pump is connected to the other end of the sampling tube and is used to provide a negative pressure environment in the sampling tube to control the sampling needle to take samples; The pressure relief valve is used to restore the pressure in the sampling needle to normal after sampling is completed.

[0006] Optionally, the sampling needle is formed of a high temperature resistant material, and the high temperature resistant material includes stainless steel and nickel-based alloy.

[0007] Optionally, a light-shielding material layer is provided on the surface of the sampling tube.

[0008] Optionally, the extraction mechanism further includes: The heat-insulating structure is arranged on the outside or inside of the sampling tube, and the heat-insulating structure comprises a first heat-insulating layer, an anti-corrosion layer and a second heat-insulating layer stacked in sequence.

[0009] Optionally, the first thermal insulation layer, the anti-corrosion layer and the second thermal insulation layer are sequentially stacked on the outside of the sampling tube; The first thermal insulation layer is a vacuum glass thermal insulation layer, the anti-corrosion layer is a glass wool layer, and the second thermal insulation layer is a foam concrete layer.

[0010] Optionally, the electron paramagnetic resonance detection platform comprises: A detection tube, used to obtain the pyrolysis product extracted by the extraction device; A detection device, used to provide a magnetic field environment and perform microwave detection, and output a spectrum signal to indicate the type and concentration of free radicals; Nitrogen protection system to prevent the pyrolysis products from being disturbed by the external environment; The outlet gas collection device is used to collect the output pyrolysis products after electron paramagnetic resonance detection.

[0011] Optionally, a stabilizer or a capture agent is provided in the detection tube, and the stabilizer or the capture agent is used to prolong the life of free radicals.

[0012] On the other hand, a control method of a burner system based on an EPR detection platform is provided, wherein the control method of a burner system based on an EPR detection platform is applicable to the burner system based on an EPR detection platform as described in any one of the above items, comprising: extracting pyrolysis products in the burner; Electron paramagnetic resonance was used to detect the free radical types and concentrations of the pyrolysis products; The control system determines the combustion state of the burner according to the type and concentration of free radicals, and adjusts the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state.

[0013] Optionally, the control system determines the combustion state of the burner according to the type and concentration of the free radicals, and regulates the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state, including: According to free radical Value and The value determines the combustion state of the burner. The value indicates the type of free radical, The values ​​indicate the concentration of free radicals; In the When the value is greater than the first threshold, it indicates that the combustion is incomplete or the combustion state is poor, and the pyrolysis temperature, coal powder concentration or air-to-powder ratio should be increased to improve the combustion state; In the When the value is greater than the second threshold, it indicates that the combustion is incomplete or the combustion state is poor. Increase the pulverized coal supply or adjust the air-powder ratio to increase the pulverized coal concentration to improve the combustion state.

[0014] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects: In the disclosed embodiment, a feedforward control strategy is adopted to regulate the air supply assembly and the feeding assembly. By adjusting the burner air volume and the amount of pulverized coal, the stable combustion of the flame can be maintained. The application of a closed-loop control system continuously optimizes the feedforward and feedback control strategies to adapt to various disturbances and changes that may occur during the combustion process. This method obtains a combustion feedforward signal by detecting the key state parameter of the free radical type and concentration of the pre-pyrolysis product, and then performs feedforward regulation through a predictive control system to reduce control lag and achieve stable combustion.

[0015] In addition, the pyrolysis products are directly extracted in the burner through the extraction mechanism, and the electron paramagnetic resonance (EPR) detection is carried out quickly and accurately to obtain the type and concentration information of the product free radicals in real time. This function is crucial for real-time monitoring of the combustion state and reflecting the information of coal flow and coal quality. By analyzing the free radical signal, the flow field change trend in the burner can be predicted, and the combustion change process and trend can be analyzed, so that timely adjustments can be made, which helps to optimize the combustion process and improve the combustion efficiency.

[0016] Finally, by real-time monitoring of the free radical types and concentrations of pre-pyrolysis products, problems in the combustion process, such as incomplete combustion and coking, can be predicted and diagnosed, and timely measures can be taken to make adjustments to ensure the stability and safety of the combustion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic structural diagram of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of an extraction mechanism provided in an embodiment of the present disclosure; Figure 3 A control flow chart of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure; Figure 4 A method flow chart of a control method of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure; Figure 5 A control flow chart of another burner system based on an EPR detection platform provided in an embodiment of the present disclosure; Figure 6 A diagram showing the relationship between free radicals and temperature provided in an embodiment of the present disclosure.

[0019] The reference numerals are as follows: 1: Burner; 2: Air supply components; 3: Feeding assembly; 4: extraction mechanism; 41: sampling needle; 42: sampling tube; 43: electric control valve; 44: vacuum pump; 45: pressure relief valve; 5: Electron paramagnetic resonance detection platform; 51: Detection tube; 52: Detection device; 53: Nitrogen protection system; 54: Outlet gas collection device; 6: Control unit; 7: Data processing unit. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Figure 1 A schematic diagram of the structure of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure. Figure 1 ,include: The burner 1 may be a swirl burner.

[0022] The air supply component 2 provides air for the burner 1 .

[0023] The feed assembly 3 provides fuel to the burner 1.

[0024] The extraction mechanism 4 is used to extract the pyrolysis products from the burner 1 .

[0025] The electron paramagnetic resonance detection platform 5 is used to detect the type and concentration of free radicals of the pyrolysis product by electron paramagnetic resonance to determine the combustion state of the burner 1 .

[0026] The control unit 6 is used to adjust the air volume provided by the air supply system 2 and the fuel volume provided by the feeding system 3 according to the combustion state of the burner 1.

[0027] In the disclosed embodiment, a feedforward control strategy is adopted to regulate the air supply assembly and the feed assembly. By adjusting the burner air volume and the amount of pulverized coal, the stable combustion of the flame can be maintained. The application of a closed-loop control system continuously optimizes the feedforward and feedback control strategies to adapt to various disturbances and changes that may occur during the combustion process. This method obtains a combustion feedforward signal by detecting the key state parameter of the free radical type and concentration of the pre-pyrolysis product, and then performs feedforward regulation through a predictive control system to reduce control lag and achieve stable combustion.

[0028] In addition, the pyrolysis products are directly extracted in the burner through the extraction mechanism, and the electron paramagnetic resonance (EPR) detection is carried out quickly and accurately to obtain the type and concentration information of the product free radicals in real time. This function is crucial for real-time monitoring of the combustion state and reflecting the information of coal flow and coal quality. By analyzing the free radical signal, the flow field change trend in the burner can be predicted, and the combustion change process and trend can be analyzed, so that timely adjustments can be made, which helps to optimize the combustion process and improve the combustion efficiency.

[0029] Finally, by real-time monitoring of the free radical types and concentrations of pre-pyrolysis products, problems in the combustion process, such as incomplete combustion and coking, can be predicted and diagnosed, and timely measures can be taken to make adjustments to ensure the stability and safety of the combustion process.

[0030] Figure 2 A schematic diagram of the structure of an extraction mechanism provided by an embodiment of the present disclosure. Figure 2 , Figure 2 for Figure 1 The extraction mechanism 4 comprises: Sampling needle 41; A sampling tube 42, one end of which is connected to the sampling needle 41; The electric control valve 43 is arranged between the sampling needle 41 and the sampling tube 42; A vacuum pump 44 is connected to the other end of the sampling tube 42 and is used to provide a negative pressure environment in the sampling tube 42 to control the sampling needle 41 to take samples; The pressure relief valve 45 is used to restore the pressure in the sampling needle 41 to normal pressure after sampling is completed.

[0031] In the embodiment of the present disclosure, the negative pressure environment is provided by a vacuum pump to realize sampling. The electric control valve can realize timed sampling, thereby realizing the function of timed monitoring of the combustion state of the burner.

[0032] In the embodiment of the present disclosure, the sampling needle is formed of a high temperature resistant material, and the high temperature resistant material includes stainless steel and nickel-based alloy. The high temperature resistant material is used to form the sampling needle, which can ensure the durability of the sampling needle.

[0033] In the disclosed embodiment, the sampling needle may be a multi-section retractable needle structure, and the sampling position and depth may be controlled according to different working conditions.

[0034] In the disclosed embodiment, a light shielding material layer is provided on the surface of the sampling tube. Providing the light shielding material layer on the surface of the sampling tube can reduce the influence of external light on the pyrolysis products in the sampling tube.

[0035] In the embodiment of the present disclosure, the sampling tube adopts a 1.0 mm (1 / 16 inch) diameter sampling tube, which reduces the attenuation of free radicals while ensuring sufficient sample volume.

[0036] In the disclosed embodiment, the inner surface of the sampling tube is specially treated to reduce the adsorption of free radicals.

[0037] In the embodiment of the present disclosure, the negative pressure environment is changed by adjusting the power of the vacuum pump, thereby controlling the sampling speed and sampling efficiency.

[0038] In the embodiment of the present disclosure, the extraction mechanism 4 further includes: The heat-insulating structure is arranged on the outside or inside of the sampling tube, and the heat-insulating structure comprises a first heat-insulating layer, an anti-corrosion layer and a second heat-insulating layer stacked in sequence.

[0039] In the disclosed embodiment, providing a heat-insulating structure is beneficial to ensuring the life of free radicals in the pyrolysis products and improving the detection accuracy.

[0040] In the disclosed embodiment, the first thermal insulation layer, the anti-corrosion layer and the second thermal insulation layer are sequentially stacked on the outside of the sampling tube; the first thermal insulation layer is a vacuum glass thermal insulation layer, the anti-corrosion layer is a glass wool layer, and the second thermal insulation layer is a foam concrete layer.

[0041] In the embodiments of the present disclosure, the thermal insulation structure formed by the above materials has a better thermal insulation effect.

[0042] See again Figure 1 , the electron paramagnetic resonance detection platform 5 comprises: A detection tube 51, used to obtain the pyrolysis product extracted by the extraction device; The detection device 52 is used to provide a magnetic field environment and perform microwave detection, and output a spectrum signal to indicate the type and concentration of free radicals; the detection device may be an EPR spectrometer (which may also include a laser).

[0043] A nitrogen protection system 53 is used to prevent the pyrolysis products from being disturbed by the external environment; The outlet gas collection device 54 is used to collect the output pyrolysis products after electron paramagnetic resonance detection.

[0044] In the embodiment of the present disclosure, free radicals in the pyrolysis products are detected by an electron paramagnetic resonance detection platform, and spectral signals are output to represent the type and concentration of the free radicals. The control unit can determine the type and concentration of the free radicals based on the spectral signals, thereby determining the combustion state of the burner.

[0045] In the embodiment of the present disclosure, the burner system based on the EPR detection platform further includes a data processing unit 7 for processing the spectral signal and transmitting the type and concentration of the free radicals obtained after the processing to the control unit.

[0046] Figure 3 A control flow chart of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure. Figure 3 The pyrolysis products of the burner are extracted through the extraction mechanism, the EPR detection platform detects the concentration and type of free radicals according to the pyrolysis products, and the predictive control system controls the adjustable mechanism of the burner according to the concentration and type of free radicals to achieve closed-loop control.

[0047] Figure 4A method flow chart of a control method of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure. Figure 4 ,include: S101, extracting pyrolysis products in the burner.

[0048] S102. Electron paramagnetic resonance is used to detect the type and concentration of free radicals in the pyrolysis products.

[0049] Specifically, the EPR detection device will output specific spectral signals of free radicals, which are directly related to the type and concentration of free radicals. The signal processing unit will amplify, filter and digitize the received signals for subsequent analysis and comparison.

[0050] S103, the control system determines the combustion state of the burner according to the type and concentration of free radicals, and adjusts the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state.

[0051] In one example, step S103 includes: According to free radical Value and The value determines the combustion state of the burner. The value indicates the type of free radical, The values ​​indicate the concentration of free radicals; In the The value is greater than the first threshold ( ), it indicates that the combustion is incomplete or the combustion state is not good. Increase the pyrolysis temperature, coal powder concentration or air-to-powder ratio to improve the combustion state. In the The value is greater than the second threshold ( ), it indicates that the combustion is incomplete or the combustion state is not good. Increase the pulverized coal supply or adjust the air-powder ratio to increase the pulverized coal concentration to improve the combustion state.

[0052] In the embodiment of the present disclosure, by determining the free radical Value and The combustion state of the burner can be determined by the value. Value and The value is adjusted to regulate the air supply components and the feeding components to realize the control of the combustion state of the burner.

[0053] Figure 5 Another control flow chart of a burner system based on an EPR detection platform provided in an embodiment of the present disclosure. Figure 5 , and judge whether the free radical concentration is within the normal range based on the preset threshold.

[0054] Generate a low pyrolysis temperature signal based on the threshold comparison result and low coal powder quantity signal , and then get the burner adjustable mechanism control signal Wind and powder ratio control signal Control and adjust the burner's adjustable structure, air supply system and powder feeding system, including adjusting the burner's swirl blade strength, nozzle angle, etc. to affect the combustion swirl intensity, air-powder mixing degree and high-temperature flue gas entrainment intensity; adjusting the powder feeder speed to increase the powder feeding amount and coal powder concentration; adjusting the primary and secondary air valve opening to adjust the primary and secondary air volume and ratio to affect the air-powder ratio.

[0055] Specifically, the control unit will compare the free radical signal output by the EPR detection platform with the preset threshold. If the detected free radical concentration exceeds the normal range, the control system will automatically adjust the key control parameters of the burner adjustable structure, air supply system and powder feeding system.

[0056] After completing the control, the threshold comparison module is returned to further calculate the difference. When each key parameter reaches the normal range, the actuator will no longer be adjusted, thereby realizing feedback regulation. Through the closed-loop control system, the feedforward and feedback control strategies are continuously optimized to adapt to various disturbances and changes that may occur during the combustion process.

[0057] Figure 6 A diagram showing the relationship between free radicals and temperature provided in an embodiment of the present disclosure. Figure 6 In the early stage of coal powder combustion, coal begins to pyrolyze, volatile matter is released, coke is produced, and the free radical content increases significantly. As the temperature rises, the coke begins to burn, the free radicals combine with oxygen and react, and the free radical content decreases significantly.

[0058] As the oxidation combustion process of coal progresses, the g factors of different types of coal show a downward trend. This is because during the oxidation combustion process, as volatile matter is released and burned and coke is oxidized and burned into ash, sulfur-containing substances in the coal are released. Sulfur-containing free radicals with high g factors (g factors 2.0080~2.0081) are almost non-existent in the combustion residues, so the g factor is greatly reduced.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A burner system based on an EPR detection platform, characterized in that: include: Burner; An air supply component, providing air for the burner; A feed assembly, which provides fuel to the burner; An extraction mechanism, used for extracting pyrolysis products from the burner; An electron paramagnetic resonance detection platform is used to detect the type and concentration of free radicals in pyrolysis products using electron paramagnetic resonance to determine the combustion state of the burner; The control unit is used to adjust the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state of the burner.

2. The burner system based on the EPR detection platform according to claim 1, characterized in that: The extraction mechanism comprises: Sampling needle; A sampling tube, one end of which is connected to the sampling needle; An electric control valve is arranged between the sampling needle and the sampling tube; A vacuum pump is connected to the other end of the sampling tube and is used to provide a negative pressure environment in the sampling tube to control the sampling needle to take samples; The pressure relief valve is used to restore the pressure in the sampling needle to normal after sampling is completed.

3. The burner system based on the EPR detection platform according to claim 2, characterized in that: The sampling needle is formed of high temperature resistant material, and the high temperature resistant material includes stainless steel and nickel-based alloy.

4. The burner system based on the EPR detection platform according to claim 2, characterized in that: A light-shielding material layer is arranged on the surface of the sampling tube.

5. The burner system based on the EPR detection platform according to claim 2, characterized in that: The extraction mechanism also includes: The heat-insulating structure is arranged on the outside or inside of the sampling tube, and the heat-insulating structure comprises a first heat-insulating layer, an anti-corrosion layer and a second heat-insulating layer stacked in sequence.

6. The burner system based on the EPR detection platform according to claim 5, characterized in that: The first thermal insulation layer, the anti-corrosion layer and the second thermal insulation layer are sequentially stacked on the outside of the sampling tube; The first thermal insulation layer is a vacuum glass thermal insulation layer, the anti-corrosion layer is a glass wool layer, and the second thermal insulation layer is a foam concrete layer.

7. The burner system based on the EPR detection platform according to claim 1, characterized in that: The electron paramagnetic resonance detection platform comprises: A detection tube, used to obtain the pyrolysis product extracted by the extraction device; A detection device, used to provide a magnetic field environment and perform microwave detection, and output a spectrum signal to indicate the type and concentration of free radicals; Nitrogen protection system to prevent the pyrolysis products from being disturbed by the external environment; The outlet gas collection device is used to collect the output pyrolysis products after electron paramagnetic resonance detection.

8. The burner system based on the EPR detection platform according to claim 6, characterized in that: A stabilizer or a trapping agent is arranged in the detection tube, and the stabilizer or the trapping agent is used to prolong the life of the free radicals.

9. A control method for a burner system based on an EPR detection platform, characterized in that: The control method of the burner system based on the EPR detection platform is applicable to the burner system based on the EPR detection platform according to any one of claims 1 to 8, comprising: extracting pyrolysis products in the burner; Electron paramagnetic resonance was used to detect the free radical types and concentrations of the pyrolysis products; The control system determines the combustion state of the burner according to the type and concentration of free radicals, and adjusts the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state.

10. The control method of the burner system based on the EPR detection platform according to claim 9, characterized in that: The control system determines the combustion state of the burner according to the type and concentration of free radicals, and regulates the air volume provided by the air supply system and the fuel volume provided by the feeding system according to the combustion state, including: According to free radical Value and The value determines the combustion state of the burner. The value indicates the type of free radical, The values ​​indicate the concentration of free radicals; In the When the value is greater than the first threshold, it indicates that the combustion is incomplete or the combustion state is poor, and the pyrolysis temperature, coal powder concentration or air-to-powder ratio should be increased to improve the combustion state; In the When the value is greater than the second threshold, it indicates that the combustion is incomplete or the combustion state is poor. Increase the pulverized coal supply or adjust the air-powder ratio to increase the pulverized coal concentration to improve the combustion state.

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