A sintering ignition control method and system

Abstract

This invention discloses a sintering ignition control method and system, comprising: maintaining the air flow rate of the ignition furnace at a set value; acquiring the real-time calorific value of the gas; calculating the theoretical air-fuel ratio based on the real-time calorific value; acquiring the current gas flow rate and determining the actual air-fuel ratio; comparing the theoretical air-fuel ratio with the actual air-fuel ratio, and adjusting the gas flow rate according to the comparison result until the difference between the two reaches a preset threshold. This invention ensures precise air-fuel ratio matching by stabilizing the air volume and adjusting the gas volume in real time according to the calorific value, achieving complete combustion and a stable temperature field, improving ignition quality, and saving gas.

Description

Technical Field

[0001] This invention relates to the field of sintering machine technology, and in particular to a sintering ignition control method and system. Background Technology

[0002] The ignition control in the sintering machine production process uses an automatic adjustment method, which automatically adjusts the air volume according to changes in the ignition furnace temperature. This method has the following disadvantages:

[0003] The ignition temperature value is highly susceptible to various interferences, failing to accurately reflect the true ignition temperature and resulting in data distortion. This type of regulation involves adjusting air while maintaining a constant gas supply. However, the unstable pressure and calorific value of the gas cause instability in the temperature field between the ignition furnace and the gas. This unstable temperature field, in turn, affects the ignition temperature value. Adjusting air while maintaining a constant gas supply further leads to air instability. Changes in gas calorific value, air volume, and ignition temperature interact and constrain each other. Regulation based on ignition temperature has several drawbacks: firstly, the response is slow, and the data may not be accurate; secondly, there is a possibility of incomplete combustion of the gas, gas leaks in the operating area, or an excessively high oxygen excess index, causing changes in the temperature field. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a sintering ignition control method and system.

[0005] The technical solution adopted by this invention to solve its technical problem is: a sintering ignition control method, comprising:

[0006] Maintain the airflow of the ignition furnace at the set value;

[0007] Obtain the real-time calorific value of coal gas;

[0008] Calculate the theoretical air-fuel ratio based on the real-time calorific value;

[0009] Obtain the current gas flow rate of the ignition furnace, and determine the actual air-fuel ratio based on the air flow rate setpoint and the gas flow rate.

[0010] The theoretical air-fuel ratio is compared with the actual air-fuel ratio to obtain the comparison result;

[0011] Based on the comparison results, the gas flow rate of the ignition furnace is adjusted until the difference between the theoretical air-fuel ratio and the actual air-fuel ratio reaches a preset threshold.

[0012] As a further improvement of the present invention, the real-time calorific value of the gas is collected by a calorific value detection device installed on the gas transmission pipeline at a preset sampling period.

[0013] As a further improvement of the present invention, adjusting the gas flow rate of the ignition furnace according to the comparison results specifically includes:

[0014] Determine whether the absolute value of the difference between the theoretical air-fuel ratio and the actual air-fuel ratio is greater than or equal to a preset dead zone threshold.

[0015] If so, an adjustment command to increase or decrease the gas flow rate is generated based on the positive or negative direction of the difference.

[0016] As a further improvement of the present invention, adjusting the gas flow rate of the ignition furnace according to the comparison result further includes:

[0017] After the adjustment command is executed, the updated actual air-fuel ratio is continuously acquired;

[0018] Compare the theoretical air-fuel ratio with the updated actual air-fuel ratio;

[0019] When the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio is less than the preset adjustment dead zone threshold, a command to stop adjustment is generated and output.

[0020] As a further improvement of the present invention, before maintaining the air flow rate of the ignition furnace at the set value, it further includes:

[0021] Obtain the annual average calorific value of coal gas;

[0022] The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index.

[0023] Based on the sintering process parameters, determine the set value of the air flow rate required for normal production;

[0024] Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at a set value;

[0025] Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and air flow rate setting value;

[0026] Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate setting value.

[0027] As a further improvement to the present invention, a manual correction step is also included:

[0028] Obtain the manual correction coefficients from external inputs;

[0029] The target air-fuel ratio is obtained by correcting the theoretical air-fuel ratio using the manual correction coefficient.

[0030] The target air-fuel ratio is compared with the actual air-fuel ratio, and the gas flow rate of the ignition furnace is adjusted according to the comparison result.

[0031] As a further improvement of the present invention, when the manual correction coefficient is a preset benchmark value, the target air-fuel ratio is equal to the theoretical air-fuel ratio.

[0032] As a further improvement to the present invention, it also includes:

[0033] Real-time monitoring of the ignition temperature of the furnace;

[0034] When the ignition temperature exceeds the preset temperature range, an alarm signal is generated and output.

[0035] A sintering ignition control system, comprising:

[0036] The air flow control module is used to maintain the air flow of the ignition furnace at a set value;

[0037] The calorific value acquisition module is used to obtain the real-time calorific value of the gas;

[0038] The first calculation module is used to calculate the theoretical air-fuel ratio based on the real-time calorific value;

[0039] The second calculation module is used to obtain the current gas flow rate of the ignition furnace and determine the actual air-fuel ratio based on the set value of the air flow rate and the gas flow rate.

[0040] The comparison module is used to compare the theoretical air-fuel ratio with the actual air-fuel ratio to obtain a comparison result;

[0041] The adjustment module is used to adjust the gas flow rate of the ignition furnace according to the comparison result until the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio reaches a preset threshold.

[0042] As a further improvement of the present invention, an initialization module is also included, which is used for:

[0043] Obtain the annual average calorific value of coal gas;

[0044] The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index.

[0045] The set value of the air flow rate is determined based on the sintering process parameters;

[0046] Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at the set value;

[0047] Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and the set value of the air flow rate;

[0048] Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate set value.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] This invention achieves closed-loop control of "constant-air regulated gas" by maintaining the airflow at a set value and dynamically calculating the theoretical air-fuel ratio based on real-time detected gas calorific value, thereby adjusting the gas flow. This method can quickly respond to fluctuations in gas calorific value, ensuring the air-fuel ratio always approaches the optimal theoretical value, allowing for complete gas combustion, stabilizing the ignition furnace temperature field, and improving sinter quality. Simultaneously, it avoids gas waste and safety risks caused by incomplete combustion, achieving fully automatic and rapid adjustment, reducing manual intervention, and improving production efficiency and energy saving. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the process of the present invention.

[0052] Figure 2 This is a logical schematic diagram of the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0054] In order to solve the technical problems in the prior art, the present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0055] like Figure 1 As shown, this invention discloses a sintering ignition control method, comprising:

[0056] S1: Maintain the airflow of the ignition furnace at the set value;

[0057] In some implementations, before maintaining the airflow rate of the ignition furnace at a set value, the following steps are also included:

[0058] Obtain the annual average calorific value of coal gas;

[0059] The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index.

[0060] Based on the sintering process parameters, determine the set value of the air flow rate required for normal production;

[0061] Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at a set value;

[0062] Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and air flow rate setting value;

[0063] Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate setting value.

[0064] When starting up production or changing product types, the initial theoretical air-fuel ratio is calculated based on the annual average calorific value and excess oxygen index, and the initial gas volume is calculated in conjunction with the air volume setpoint determined by the process, so that the system is put into steady state.

[0065] S2: Obtain the real-time calorific value of the gas;

[0066] In some implementations, the real-time calorific value of the gas is collected by a calorific value detection device installed on the gas transmission pipeline at a preset sampling period.

[0067] By pre-setting a sampling period (e.g., 30 seconds) and using an online calorific value detection device to periodically collect the calorific value of coal gas, continuous and real-time data is provided for subsequent calculations.

[0068] S3: Calculate the theoretical air-fuel ratio based on the real-time calorific value;

[0069] Furthermore, the preset excess oxygen index is obtained; based on the real-time calorific value and excess oxygen index, the theoretical air-fuel ratio is obtained through theoretical combustion calculations.

[0070] A preset excess oxygen index (e.g., 5%) is introduced, and the theoretical air-fuel ratio is calculated using the theoretical combustion formula in conjunction with real-time calorific value, ensuring combustion occurs with an air volume slightly higher than the stoichiometric amount. This ensures complete combustion of the gas while leaving a margin to prevent the generation of CO or black smoke due to incomplete combustion, thereby improving combustion efficiency.

[0071] S4: Obtain the current gas flow rate of the ignition furnace, and determine the actual air-fuel ratio based on the air flow rate setpoint and the gas flow rate.

[0072] S5: Compare the theoretical air-fuel ratio with the actual air-fuel ratio to obtain the comparison results;

[0073] S6: Based on the comparison results, adjust the gas flow rate of the ignition furnace until the difference between the theoretical air-fuel ratio and the actual air-fuel ratio reaches the preset threshold.

[0074] The core of this invention lies in using a fixed air flow rate as a basis, calculating the theoretical air-fuel ratio by real-time detection of the gas calorific value, and adjusting the gas flow rate after comparing it with the actual air-fuel ratio, thus forming a closed-loop control based on calorific value feedforward and air-fuel ratio feedback. This ensures a constant air volume, eliminating the interference of air fluctuations on combustion; and dynamically adjusts the gas volume according to changes in calorific value, keeping the air-fuel ratio close to the theoretical value, achieving complete combustion and temperature stability.

[0075] In some implementations, adjusting the gas flow rate of the ignition furnace based on the comparison results specifically includes:

[0076] Determine whether the absolute value of the difference between the theoretical air-fuel ratio and the actual air-fuel ratio is greater than or equal to a preset dead zone threshold.

[0077] If so, an adjustment command to increase or decrease the gas flow rate is generated based on the positive or negative direction of the difference.

[0078] Set an adjustment dead zone threshold (e.g., 0.05). When the absolute value of the difference between the theoretical air-fuel ratio and the actual air-fuel ratio exceeds this threshold, the system determines that adjustment is needed and issues instructions to increase or decrease gas according to the direction of the deviation.

[0079] Furthermore, adjusting the gas flow rate of the ignition furnace based on the comparison results also includes:

[0080] After the adjustment command is executed, the updated actual air-fuel ratio is continuously acquired;

[0081] Compare the theoretical air-fuel ratio with the updated actual air-fuel ratio;

[0082] When the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio is less than the preset adjustment dead zone threshold, a command to stop adjustment is generated and output.

[0083] After executing the adjustment command, the actual air-fuel ratio is continuously monitored. Adjustment stops when the difference narrows to within the threshold, thus completing a full adjustment cycle. This ensures proper adjustment, preventing overshoot or undershoot, and allows the air-fuel ratio to precisely converge to the target value.

[0084] Some implementations also include a manual correction step:

[0085] Obtain the manual correction coefficients from external inputs;

[0086] The target air-fuel ratio is obtained by correcting the theoretical air-fuel ratio using the manual correction coefficient.

[0087] The target air-fuel ratio is compared with the actual air-fuel ratio, and the gas flow rate of the ignition furnace is adjusted according to the comparison result.

[0088] Operators are allowed to manually input correction coefficients based on special circumstances such as material changes and material layer thickness. These coefficients are used to adjust the theoretical air-fuel ratio and generate a new target air-fuel ratio for control.

[0089] Furthermore, when the manual correction coefficient is set to a preset baseline value, the target air-fuel ratio equals the stoichiometric air-fuel ratio.

[0090] In some implementations, an ignition temperature monitoring function is added. When the temperature exceeds a preset range, an alarm signal is issued to remind the operator to check the system status. Specifically, this includes: real-time monitoring of the ignition temperature of the furnace; and generating and outputting an alarm signal when the ignition temperature exceeds a preset temperature range.

[0091] Based on the same inventive concept, the present invention also provides a sintering ignition control system, comprising:

[0092] The air flow control module is used to maintain the air flow of the ignition furnace at a set value;

[0093] The calorific value acquisition module is used to obtain the real-time calorific value of the gas;

[0094] The first calculation module is used to calculate the theoretical air-fuel ratio based on the real-time calorific value;

[0095] The second calculation module is used to obtain the current gas flow rate of the ignition furnace and determine the actual air-fuel ratio based on the set value of the air flow rate and the gas flow rate.

[0096] The comparison module is used to compare the theoretical air-fuel ratio with the actual air-fuel ratio to obtain a comparison result;

[0097] The adjustment module is used to adjust the gas flow rate of the ignition furnace according to the comparison result until the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio reaches a preset threshold.

[0098] The automated execution of the above control method is achieved through the coordinated operation of the air flow control module, calorific value acquisition module, first / second calculation module, comparison module, and adjustment module.

[0099] Specifically, an online gas calorific value detector is installed before the gas is fed into the sintering combustion chamber. Based on the annual average gas calorific value and considering the actual sintering conditions, a 5% excess oxygen index is set. The required air volume for normal production is determined according to theoretical calculations, and the air volume is adjusted and stabilized. The gas calorific value is measured every 30 seconds, and the theoretical air-fuel ratio is calculated. The theoretical air-fuel ratio is compared with the actual air-fuel ratio; if the difference is ≥0.05, gas adjustment is performed. Adjustment is considered complete when the gas calorific value reaches a point where the difference between the theoretical and actual air-fuel ratios is within ±0.05.

[0100] This invention uses "constant-air regulated gas" to stabilize the temperature field of the entire ignition zone, resulting in more stable sintering quality and better ignition effect; it is suitable for situations where the calorific value of the gas varies greatly, such as mixed gas; it can ensure complete combustion of the gas, avoid gas waste, thereby saving gas; and it can quickly detect, react, and adjust in place.

[0101] In some implementations, an initialization module is also included, for:

[0102] Obtain the annual average calorific value of coal gas;

[0103] The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index.

[0104] The set value of the air flow rate is determined based on the sintering process parameters;

[0105] Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at the set value;

[0106] Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and the set value of the air flow rate;

[0107] Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate set value.

[0108] Furthermore, the calorific value acquisition module collects the real-time calorific value of the gas through a calorific value detection device installed on the gas transmission pipeline at a preset sampling period.

[0109] Furthermore, the comparison module is also used to calculate the difference between the theoretical air-fuel ratio and the actual air-fuel ratio; the adjustment module is also used to: determine whether the absolute value of the difference is greater than or equal to the preset adjustment dead zone threshold, and if so, generate an adjustment command to increase the gas flow rate or decrease the gas flow rate according to the positive or negative direction of the difference.

[0110] The adjustment module is also used to: continuously acquire the updated actual air-fuel ratio after the adjustment command is executed; compare the theoretical air-fuel ratio with the updated actual air-fuel ratio; and generate and output a command to stop adjustment when the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio is less than a preset adjustment dead zone threshold.

[0111] Implementation Case 1:

[0112] like Figure 2 As shown, this embodiment discloses a sintering ignition control method that achieves rational use of coal gas, ensuring the temperature field of the ignition zone while rapidly adjusting according to changes in the calorific value of the coal gas, thus preventing gas waste. Specifically, it includes the following steps:

[0113] 1. An online gas calorific value detector is installed in the pipeline for transporting gas into the sintering combustion chamber.

[0114] 2. Based on the annual average calorific value of coal gas and combined with the actual sintering conditions, a 5% excess oxygen index is set, and the amount of air required for normal production is determined according to theoretical calculations.

[0115] 3. After adjusting to the appropriate air volume, stabilize this flow rate.

[0116] 4. Detect the calorific value of the gas every 30 seconds (adjustable) and calculate the theoretical air-fuel ratio.

[0117] 5. If the difference between the theoretical air-fuel ratio and the actual air-fuel ratio is ≥0.05, then gas adjustment should be performed.

[0118] 6. Once the gas value is adjusted to the point where the air-fuel ratio is less than ±0.05 of the theoretical air-fuel ratio, the adjustment is considered complete.

[0119] 7. A manual adjustment coefficient is set. Under normal circumstances, it is 1. The air-fuel ratio is multiplied by the coefficient and then exported. In case of abnormalities, such as changes in material or material bed height, when different gas quantities are required, the coefficient can be manually entered for optimization.

[0120] In actual production, mixed gas is used, with an average calorific value of 12640 kJ / nm. 3 Calculations show the theoretical air-fuel ratio is 1.49. Based on a 5% excess air-fuel ratio, the optimal air-fuel ratio is 1.56. The set air-fuel ratio is 2950m. 3 / h, then the gas volume is 1891m³ 3 / h.

[0121] The computer program detects the calorific value of the gas every 30 seconds, then recalculates the optimal air-fuel ratio A and compares it with the actual air-fuel ratio B at this time. If AB ≥ ±0.05, the program adjusts the direction accordingly; otherwise, it remains unchanged.

[0122] The adjustment is considered complete when the gas value is adjusted to a point where the air-fuel ratio is less than or equal to the theoretical air-fuel ratio by ±0.05.

[0123] This embodiment employs a "constant-air regulated gas" mode, which stabilizes the temperature field throughout the ignition zone, resulting in more stable sintering quality and better ignition performance. It is suitable for applications with significant variations in gas calorific value, such as mixed gases, ensuring complete combustion, preventing gas waste, and thus saving gas. It allows for rapid detection, rapid response, and rapid adjustment, eliminating the need for manual operation and implementing a fully automated process, thereby reducing labor intensity.

[0124] The main functions of this invention are:

[0125] 1. Ensure complete combustion of gas. Based on the theoretical air-fuel ratio, plus a 5% excess air index, ensure complete combustion of gas, thereby avoiding gas waste and unsafe conditions.

[0126] 2. Ensure temperature stability. This invention uses controlled-air refrigerated gas and automatically adjusts the stoichiometric air-fuel ratio based on changes in the gas's calorific value, ensuring temperature stability in the ignition furnace area, thereby improving ignition efficiency and sinter quality.

[0127] 3. This invention is safe and reliable, and can be automatically and quickly adjusted to the correct position, saving manpower and resources.

[0128] 4. This invention requires fewer devices, has clear logic, is easy to replace, and has low cost.

[0129] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A sintering ignition control method, characterized in that, include: Maintain the airflow of the ignition furnace at the set value; Obtain the real-time calorific value of coal gas; Calculate the theoretical air-fuel ratio based on the real-time calorific value; Obtain the current gas flow rate of the ignition furnace, and determine the actual air-fuel ratio based on the air flow rate setpoint and the gas flow rate. The theoretical air-fuel ratio is compared with the actual air-fuel ratio to obtain the comparison result; Based on the comparison results, the gas flow rate of the ignition furnace is adjusted until the difference between the theoretical air-fuel ratio and the actual air-fuel ratio reaches a preset threshold.

2. The sintering ignition control method according to claim 1, characterized in that, The real-time calorific value of the gas is collected by a calorific value detection device installed on the gas transmission pipeline at a preset sampling period.

3. The sintering ignition control method according to claim 1, characterized in that, Based on the comparison results, adjusting the gas flow rate of the ignition furnace specifically includes: Determine whether the absolute value of the difference between the theoretical air-fuel ratio and the actual air-fuel ratio is greater than or equal to a preset dead zone threshold. If so, an adjustment command to increase or decrease the gas flow rate is generated based on the positive or negative direction of the difference.

4. The sintering ignition control method according to claim 3, characterized in that, Adjusting the gas flow rate of the ignition furnace based on the comparison results further includes: After the adjustment command is executed, the updated actual air-fuel ratio is continuously acquired; Compare the theoretical air-fuel ratio with the updated actual air-fuel ratio; When the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio is less than the preset adjustment dead zone threshold, a command to stop adjustment is generated and output.

5. The sintering ignition control method according to claim 1, characterized in that, Before maintaining the airflow to the ignition furnace at the set value, the following steps are also included: Obtain the annual average calorific value of coal gas; The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index. Based on the sintering process parameters, determine the set value of the air flow rate required for normal production; Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at a set value; Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and air flow rate setting value; Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate setting value.

6. The sintering ignition control method according to claim 1, characterized in that, It also includes manual correction steps: Obtain the manual correction coefficients from external inputs; The target air-fuel ratio is obtained by correcting the theoretical air-fuel ratio using the manual correction coefficient. The target air-fuel ratio is compared with the actual air-fuel ratio, and the gas flow rate of the ignition furnace is adjusted according to the comparison result.

7. The sintering ignition control method according to claim 6, characterized in that, When the manual correction coefficient is a preset benchmark value, the target air-fuel ratio is equal to the stoichiometric air-fuel ratio.

8. The sintering ignition control method according to claim 1, characterized in that, Also includes: Real-time monitoring of the ignition temperature of the furnace; When the ignition temperature exceeds the preset temperature range, an alarm signal is generated and output.

9. A sintering ignition control system, characterized in that, include: The air flow control module is used to maintain the air flow of the ignition furnace at a set value; The calorific value acquisition module is used to obtain the real-time calorific value of the gas; The first calculation module is used to calculate the theoretical air-fuel ratio based on the real-time calorific value; The second calculation module is used to obtain the current gas flow rate of the ignition furnace and determine the actual air-fuel ratio based on the set value of the air flow rate and the gas flow rate. The comparison module is used to compare the theoretical air-fuel ratio with the actual air-fuel ratio to obtain a comparison result; The adjustment module is used to adjust the gas flow rate of the ignition furnace according to the comparison result until the difference between the theoretical air-fuel ratio and the updated actual air-fuel ratio reaches a preset threshold.

10. A sintering ignition control system according to claim 9, characterized in that, It also includes an initialization module, used for: Obtain the annual average calorific value of coal gas; The initial theoretical air-fuel ratio is calculated based on the annual average calorific value of the gas and the preset excess oxygen index. The set value of the air flow rate is determined based on the sintering process parameters; Output an airflow adjustment command to adjust and maintain the airflow of the ignition furnace at the set value; Calculate the initial gas flow rate setting value based on the initial theoretical air-fuel ratio and the set value of the air flow rate; Output an initial gas flow rate adjustment command to adjust the gas flow rate of the ignition furnace to the initial gas flow rate set value.

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