Sintering flue gas circulation system and method based on annular cold waste gas characteristic matching

Abstract

The invention provides a sintering flue gas circulation system and method based on annular cold waste gas characteristic matching. The system comprises a sintering machine, an ignition heat preservation cover and a circulating flue gas cover which are arranged above the sintering machine, and an annular cooler, and further comprises at least two annular cooling waste gas leading-out loops which are respectively communicated with different segmented areas, capable of leading out annular cooling waste gas with different temperature and oxygen content combined characteristics, on the annular cooler; the annular cooling waste gas injection loops correspond to the annular cooling waste gas leading-out loops in number, and the annular cooling waste gas led out by the annular cooling waste gas leading-out loops serves as process gas to be directly conveyed to different injection areas above the sintering machine. The injection area at least comprises a first injection area arranged in the ignition heat preservation cover and a second injection area arranged in the head area of the circulating flue gas cover; the flow field regulation and control device comprises at least one guide plate assembly of which the opening degree is controlled by a driving module; and a control unit. According to the invention, efficient utilization of the annular cooling waste gas, optimization of the sintering process and improvement of the quality of sintered ore are realized.

Description

Technical Field

[0001] The present invention relates to a sintering flue gas circulation system, in particular to a sintering flue gas circulation system and method based on ring-cooling waste gas characteristic matching, belonging to the technical field of sintering flue gas treatment. Background Art

[0002] Sintering is a critical process in steel production and a major source of energy consumption and pollutant emissions. Reintroducing a portion of sintering flue gas into the sintering process effectively recovers waste heat, reduces fuel consumption, and lowers pollutant emissions, making it a key approach to energy conservation and emission reduction in the sintering process. Traditionally, the exhaust gas from the ring cooler is indiscriminately or simply mixed before being introduced into the ignition and holding area of the sintering machine or above the sinter bed. However, the exhaust gas from the ring cooler exhibits significant differences in key characteristics, such as temperature and oxygen content, at different stages of cooling the sinter. For example, exhaust gas from the high-temperature section of the ring cooler has a high temperature but low oxygen content, while exhaust gas from the medium and low-temperature sections has a lower temperature but relatively high oxygen content. Therefore, traditional methods fail to fully utilize the exhaust gas characteristics, resulting in low heat recovery efficiency or impacting sintering process stability and sinter quality due to inappropriate oxygen content. Furthermore, traditional methods lack flexibility in controlling the exhaust gas injection area and injection rate, making it difficult to adapt to dynamic sintering conditions and unable to achieve precise control of the atmosphere above the sinter bed. The introduced circulating flue gas is often unevenly distributed in the circulating flue gas hood, which may cause local overheating or underheating of the sintering material layer surface, affecting the uniformity and yield of the sintered ore.

[0003] Therefore, how to make full use of the characteristics of waste gas, improve energy utilization efficiency, improve sintered ore quality and reduce pollutant emissions is a technical problem that needs to be urgently solved in the current field of sintering flue gas circulation technology. Summary of the Invention

[0004] Based on the above background, the purpose of the present invention is to provide a sintering flue gas circulation system and method based on the matching of the characteristics of the ring cooling exhaust gas. According to the requirements of temperature and oxygen content at different stages of the sintering process, the exhaust gas from different sections of the ring cooler is monitored and selectively utilized in real time. By controlling the injection flow rate and regulating the flow field distribution in the circulating flue gas hood, the efficient utilization of the ring cooling exhaust gas, the optimization of the sintering process and the improvement of the quality of the sintered ore are achieved.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A sintering flue gas circulation system based on matching the characteristics of annular cooling exhaust gas comprises a sintering machine, an ignition and heat preservation hood and a circulating flue gas hood arranged above the sintering machine, and an annular cooler for cooling sintered ore. The sintering flue gas circulation system further comprises:

[0007] At least two independent ring-cooling exhaust gas outlet circuits, each of which is connected to a different segmented area of the ring-cooling machine capable of extracting ring-cooling exhaust gas with different temperature and oxygen content combination characteristics, and each ring-cooling exhaust gas outlet circuit is provided with an online sensor assembly, which is used to monitor the temperature and oxygen content of the ring-cooling exhaust gas extracted by the ring-cooling exhaust gas outlet circuit in real time;

[0008] Annular cooling waste gas injection circuits corresponding to the number of the annular cooling waste gas outlet circuits, each annular cooling waste gas injection circuit respectively transports the annular cooling waste gas outlet circuit as process gas directly to different injection areas above the sintering machine, the injection areas at least including a first injection area arranged inside the ignition and heat preservation cover and a second injection area arranged in the head area of the circulating fume hood, and each annular cooling waste gas injection circuit is provided with a flow control component;

[0009] A flow field regulating device, the flow field regulating device comprising at least one guide plate assembly whose opening is controlled by a driving module, the guide plate assembly being arranged inside the circulating fume hood; and

[0010] A control unit is electrically connected to the online sensor assembly, the flow control assembly, and the drive module of the flow field control device, and is configured to execute the following control strategy:

[0011] Based on the temperature and oxygen content of the ring cooling waste gas monitored in real time by the online sensor assembly, and in combination with the predetermined target temperature and predetermined target oxygen concentration during the ignition stage and the front end of the sintering machine, the operation of one or more corresponding ring cooling waste gas outlet circuits and ring cooling waste gas injection circuits is selected and adjusted;

[0012] Controlling the flow control component so that the selected annular cooling exhaust gas is injected into the first injection area and the second injection area at the calculated flow rate respectively;

[0013] The opening of the guide plate assembly of the flow field regulating device is controlled according to the combined characteristics of the temperature and oxygen content of the injected annular cooling exhaust gas and the flow rate of the annular cooling exhaust gas.

[0014] Preferably, the injection zone further includes a third injection zone arranged in the middle or rear area of the circulating fume hood.

[0015] Preferably, there are multiple guide plate assemblies, and the multiple guide plate assemblies are distributed along the length direction of the circulating fume hood to form a guide plate array.

[0016] Preferably, the guide plate assembly is arranged in parallel along the length direction of the circulating smoke hood, and each of the guide plate assemblies includes a plurality of guide plate members arranged at intervals along the extension direction of the column and capable of rotating independently around their side shafts, the guide plate members are hinged to the circulating smoke hood, and the end portion of the other side of each of the guide plate members is fixedly connected to a driving gear, and the inside of the circulating smoke hood is provided with a long rack arranged along the extension direction of the guide plate assembly corresponding to each of the guide plate assemblies, the long rack is meshed with the driving gears of all the guide plate members of the guide plate assembly, and at least one end of the long rack is fixedly connected to the output end of a driving module arranged outside the circulating smoke hood, the driving module causes the long rack to produce a linear reciprocating motion, thereby driving all the guide plates in the guide plate assembly to rotate synchronously to adjust their deflection angles, and the control unit can separately control the driving modules that drive different guide plate assemblies, so that the guide plates in any two adjacent guide plate assemblies have relative deflection directions.

[0017] A sintering flue gas circulation method based on matching the characteristics of annular cooling exhaust gas is applied to a sintering flue gas circulation system comprising a sintering machine, an ignition and heat-insulating hood and a circulating flue gas hood arranged above the sintering machine, and an annular cooler for cooling sintered ore. The method comprises the following steps:

[0018] The ring-cooled exhaust gas is drawn out from different segmented areas of the ring-cooler capable of drawing out ring-cooled exhaust gas having different temperature and oxygen content combination characteristics through at least two mutually independent ring-cooled exhaust gas drawing-out circuits, and the temperature and oxygen content of the drawn-out ring-cooled exhaust gas are monitored in real time by an online sensor assembly provided on each ring-cooled exhaust gas drawing-out circuit;

[0019] The extracted ring cooling waste gas from each channel is used as process gas and injected directly into different injection areas above the sintering machine through the corresponding ring cooling waste gas injection circuit. The injection areas include at least a first injection area inside the ignition and heat preservation cover and a second injection area in the head area of the circulating gas hood.

[0020] The control unit selects to start and adjust the operation of one or more corresponding ring cooling waste gas outlet circuits and ring cooling waste gas injection circuits based on the temperature and oxygen content of the ring cooling waste gas monitored in real time by the online sensor assembly, in combination with the predetermined target temperature and predetermined target oxygen concentration during the ignition stage and the front stage of the sintering machine;

[0021] Controlling, by means of a control unit, a flow control component provided on each annular cooling exhaust gas injection circuit so that the selected annular cooling exhaust gas is injected into the first injection zone and the second injection zone at a calculated flow rate, respectively;

[0022] The control unit controls the opening of the guide plate assembly of the flow field control device arranged inside the circulating fume hood according to the combined characteristics of the temperature and oxygen content of the injected annular cooling exhaust gas and the flow rate of the annular cooling exhaust gas.

[0023] Preferably, the injection zone also includes at least one third injection zone in the middle or rear area of the circulating fume hood, and the ring cooling waste gas is selectively injected by the corresponding ring cooling waste gas injection circuit and flow control component according to the predetermined process requirements of the middle and rear stages of sintering through the control unit.

[0024] Preferably, the control unit follows the following preset priority rules when selecting the best matching ring-cooled exhaust gas, first meeting the heat demand of the first injection zone in the ignition insulation hood, and secondly meeting the oxygen content and preheating requirements of the second injection zone in the head area of the circulating flue gas hood.

[0025] Preferably, the method further comprises the following steps: reading the periodically input preset sintered ore quality index and / or energy consumption index by the control unit, and adjusting the predetermined target temperature and predetermined target oxygen concentration of the sintering machine ignition stage and the front section of sintering.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The sintering flue gas circulation system and method based on the matching of the characteristics of the annular cooling exhaust gas of the present invention can match the annular cooling exhaust gas with different characteristics to the specific needs of different stages of the sintering process through branching, real-time monitoring and selection, and maximize the recovery and utilization of the waste heat and useful components of the waste gas. By controlling the injection flow rate and the flow field distribution in the circulating flue gas hood, it can provide a more stable and uniform process atmosphere for the sintering material layer, reduce the instability of the sintering process caused by fluctuations or uneven distribution of the exhaust gas characteristics, and directly reduce the fuel consumption in the ignition and sintering process by efficiently recovering the waste heat of the annular cooling exhaust gas. At the same time, the internal circulation of the flue gas also greatly reduces the amount of exhaust gas and the total amount of pollutants therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0029] Figure 1 This is a structural schematic diagram of a sintering flue gas circulation system based on ring cooling exhaust gas characteristic matching according to the present invention;

[0030] Figure 2 It is a structural schematic diagram of the flow field control device in the present invention;

[0031] Figure 3 yes Figure 2 A partial enlarged view of part A in the middle;

[0032] Figure 4 This is a comparison chart of the technical effects of the present invention and the traditional sintering flue gas circulation solution;

[0033] In the figure: 1. Sintering machine; 2. Ignition insulation cover; 3. Circulating flue gas hood; 4. Circulating cooler; 5. Circulating cooling waste gas outlet circuit; 6. Online sensor assembly; 7. Circulating cooling waste gas injection circuit; 8. Flow control assembly; 9. First injection area; 10. Second injection area; 11. Third injection area; 12. Flow field control device; 13. Guide plate assembly; 14. Drive module; 15. Control unit; 16. Multi-tube dust collector; 17. Waste heat recovery boiler; 18. Circulating flue gas induced draft fan; 31. Circulating flue gas hood head area; 32. Circulating flue gas hood middle area; 33. Circulating flue gas Rear area of the hood; 41. High-temperature section of the annular cooler; 42. Medium-temperature section of the annular cooler; 43. Low-temperature oxygen-rich section of the annular cooler; 5a. First annular cooling exhaust gas outlet circuit; 5b. Second annular cooling exhaust gas outlet circuit; 5c. Third annular cooling exhaust gas outlet circuit; 6a. Temperature sensor; 6b. Oxygen content analyzer; 7a. First annular cooling exhaust gas injection circuit; 7b. Second annular cooling exhaust gas injection circuit; 7c. Third annular cooling exhaust gas injection circuit; 8a. First induced draft fan; 8b. Second induced draft fan; 8c. Third induced draft fan; 131. Guide plate; 132. Drive gear; 133. Long rack. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the scope of protection of the present invention.

[0035] In the present invention, unless otherwise specified, all parts and percentages are by weight. The equipment and raw materials used are commercially available or commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are all universal standard parts or components known to those skilled in the art. Their structures and principles are known to those skilled in the art through technical manuals or routine experimental methods.

[0036] The following detailed description of the embodiments of the present invention is made in conjunction with the accompanying drawings. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, one or more embodiments may be implemented by those skilled in the art without these specific details.

[0037] The embodiment of the present invention discloses a sintering flue gas circulation system based on the matching of the characteristics of the ring cooling exhaust gas, such as Figure 1 As shown, this system, used in a typical belt sintering process, comprises a sintering machine 1, an ignition and heat-insulating hood 2 for ignition and heat preservation, and a recirculating flue gas hood 3 for introducing circulating flue gas, positioned above the sintering machine 1 along its length. A ring cooler 4 is connected to the end of the sintering machine 1 to cool the high-temperature sintered ore. The sintering flue gas recirculation system also includes three independent ring cooling waste gas extraction circuits 5, three ring cooling waste gas injection circuits 7, a flow field control device 12, and a control unit 15.

[0038] Three independent annular cooling exhaust gas outlet loops 5 are provided: the first annular cooling exhaust gas outlet loop 5a, the second annular cooling exhaust gas outlet loop 5b, and the third annular cooling exhaust gas outlet loop 5c. These outlet loops connect to different segmented areas of the annular cooler 4, capable of extracting gases with different temperature and oxygen content combinations. The first annular cooling exhaust gas outlet loop 5a is connected to the high-temperature section 41 of the annular cooler 4. The exhaust gas in this section typically has a higher temperature, reaching 600-800°C, but a lower oxygen content, typically 5%-10%. The second annular cooling exhaust gas outlet loop 5b is connected to the medium-temperature section 42 of the annular cooler 4. The exhaust gas in this section has a moderate temperature, reaching 300-500°C, and a medium oxygen content, typically 10%-15%. The third annular cooling exhaust gas outlet loop 5c is connected to the low-temperature, oxygen-rich section 43 of the annular cooler 4. The exhaust gas temperature in this section is relatively low, usually 150-300°C, but the oxygen content is relatively high, reaching 15% - 20%, which is close to or slightly lower than the oxygen content in the air.

[0039] Each of the annular cooling exhaust gas outlet loops 5a, 5b, and 5c is equipped with an online sensor assembly 6 for real-time monitoring of key parameters of the annular cooling exhaust gas. This online sensor assembly 6 includes a temperature sensor 6a for monitoring temperature and an oxygen analyzer 6b for monitoring oxygen content. The temperature sensor 6a is specifically a sheathed thermocouple, and the oxygen analyzer 6b is specifically a zirconia oxygen analyzer.

[0040] The three annular cooling waste gas injection loops 7 correspond to the three annular cooling waste gas outlet loops: the first annular cooling waste gas injection loop 7a, the second annular cooling waste gas injection loop 7b, and the third annular cooling waste gas injection loop 7c. High temperatures are required within the ignition and heat preservation hood 2 to maintain the ignition temperature of the sintering material bed and reduce ignition fuel consumption. Therefore, the first annular cooling waste gas injection loop 7a primarily delivers the high-temperature, low-oxygen waste gas drawn from the first annular cooling waste gas outlet loop 5a to the first injection zone 9 located within the ignition and heat preservation hood 2. The head area 31 of the circulating flue gas hood, located after the ignition and heat preservation hood, injects waste gas with the appropriate temperature and oxygen content to help preheat the incoming sintering material bed and provide the necessary oxygen for the early stages of sintering, stabilizing the combustion zone. Therefore, the second annular cooling waste gas injection loop 7b delivers the medium-temperature, medium-oxygen waste gas drawn from the second annular cooling waste gas outlet loop 5b to the second injection zone 10 located in the head area 31 of the circulating flue gas hood 3. In the latter stages of the sintering process, oxygen supplementation is required to ensure complete sintering or adjust the temperature distribution. Therefore, the third annular cooling exhaust gas injection circuit 7c conveys the low-temperature oxygen-rich exhaust gas drawn out from the third annular cooling exhaust gas outlet circuit 5c to the third injection zone 11 arranged in the middle area 32 or the rear area 33 of the circulating fume hood 3.

[0041] Each of the annular cooling exhaust gas injection loops 7a, 7b, and 7c is provided with a flow control component 8, specifically an induced draft fan controlled by a frequency converter, namely a first induced draft fan 8a, a second induced draft fan 8b, and a third induced draft fan 8c.

[0042] like Figure 2 and Figure 3 As shown, the flow field control device 12 includes a plurality of guide plate assemblies 13 distributed along the length of the circulating fume hood 3, forming a guide plate array. Each guide plate assembly 13 is arranged parallel to the length of the circulating fume hood 3 (i.e., the direction of the guide plate's rotation axis is perpendicular to the direction of operation of the sintering machine). Each guide plate assembly 13 includes a plurality of guide plate members 131 spaced apart along the extension direction of the column (i.e., perpendicular to the direction of operation of the sintering machine) and independently rotatable around their side rotation axes. These guide plate members 131 are hinged to the internal support structure of the circulating fume hood 3 via a rotation axis. A drive gear 132 is fixed to the end of the other side (non-rotation axis side) of each guide plate member 131.

[0043] Corresponding to each deflector assembly 13, a long rack 133 is provided inside the circulating smoke hood 3 along the extension direction of the deflector assembly. The long rack 133 is meshed with the drive gears 132 of all the deflector parts 131 in the deflector assembly. One end of the long rack 133 is fixedly connected to the output end of the drive module 14 provided outside the circulating smoke hood 3 via a connecting rod. The drive module 14 uses an electric push rod or a cylinder to enable it to drive the long rack 133 to produce linear reciprocating motion. When the long rack 133 moves, through the meshing of the gear rack, it can synchronously drive all the deflector parts 131 in the deflector assembly 13 to rotate around their respective rotation axes, thereby uniformly adjusting their deflection angles (i.e., openings).

[0044] The control unit 15 can independently control the drive modules 14 of different deflector assemblies 13, thereby enabling the deflector elements 131 in any two adjacent deflector assemblies to have relative deflection directions. Specifically, if the deflector elements of one deflector assembly deflect upward, the deflector elements of the adjacent deflector assembly deflect downward, thereby creating a diversion effect of airflow divergence and disturbance within the recirculating fume hood, forming diverging and interlaced flows.

[0045] The control unit 15 is a programmable logic controller and is electrically connected to all online sensor components 6, all flow control components 8, and all drive modules 14. The control unit 15 is configured to execute the following core control strategies:

[0046] The control unit 15 collects in real time the temperature and oxygen content of each circulating cooling exhaust gas (from the high-temperature section 41, the medium-temperature section 42, and the low-temperature oxygen-enriched section 43), as monitored by the various online sensor assemblies 6. The control unit 15 also stores predetermined target temperatures and oxygen concentrations for the sintering machine's ignition phase and the early, mid, and late sintering stages. These target values can be pre-set based on process parameters such as sintering ore type, bed thickness, and sintering speed, and can also be updated based on subsequent optimization adjustments. Using a built-in matching algorithm, the control unit 15 compares the actual exhaust gas characteristics of each channel with the target requirements for the current sintering stage and selects one or more circulating cooling exhaust gas channels with the temperature and oxygen content combination that best matches the target. This selection follows a pre-set priority rule: first, ensuring that the heat requirements of the first injection zone 9 within the ignition and heat-insulating hood 2 are met, prioritizing exhaust gas with sufficiently high temperatures, namely, exhaust gas from the high-temperature section 41. Secondly, considering the oxygen content and preheating temperature requirements of the second injection zone 10 in the head region 31 of the circulating flue gas hood 3, exhaust gas from the medium-temperature section 42 is selected. In other words, the flow control device in the high-temperature exhaust gas injection loop is controlled based on the predetermined target temperature of the ignition insulation hood to ensure sufficient high-temperature exhaust gas injection at the target temperature. This is a key process guarantee and has the highest priority. The flow control device in the medium-temperature exhaust gas injection loop is controlled based on the predetermined target temperature and target oxygen concentration at the head of the circulating flue gas hood to adjust the injection flow rate. This is the second priority. While ensuring the highest priority target, if the characteristics of the medium-temperature exhaust gas cannot fully meet the predetermined target, the control unit will try to utilize the existing medium-temperature exhaust gas.

[0047] After selecting a suitable annular cooling exhaust gas source, the control unit 15 calculates the flow rate of each exhaust gas that needs to be injected into the first injection area 9, the second injection area 10, and the possible third injection area 11 based on the target temperature, target oxygen concentration, target heat load) and the actual characteristics of the selected exhaust gas.

[0048] Then, the control unit 15 outputs a control signal to the corresponding flow control component 8 to adjust the fan speed so that the selected ring cooling exhaust gas is injected into the designated injection area at the calculated flow rate.

[0049] According to the comprehensive characteristics of the annular cooling exhaust gas currently injected into the circulating fume hood 3 and the temperature distribution requirements on the surface of the sintering material layer, the control unit 15 outputs control signals to the various driving modules 14 of the flow field control device 12 .

[0050] By controlling the displacement of the long rack 133, the deflection angle of the guide plate member 131 in each guide plate assembly 13 is adjusted. If high-temperature exhaust gas is injected, a guide plate is needed to spread it more evenly above the material layer to avoid local overheating. If low-temperature oxygen-rich exhaust gas is injected, a guide plate is needed to guide it to specific areas where oxygen supplementation is required. By controlling the relative deflection of adjacent guide plate assemblies, a more refined flow field can be formed. The characteristics and amount of the injected gas determine the initial state of the airflow, and the flow field control device optimizes the distribution of the airflow in the hood and the contact with the material layer based on this initial state. If the gas flow rate injected into the hood head is large and the temperature is high, the opening of the guide plate will be adjusted to promote its rapid and uniform spreading and downward pressure on the material layer. If the gas injected into the hood tail is mainly for supplementing oxygen, the opening of the guide plate will be adjusted to allow it to be fully mixed with its own circulating flue gas.

[0051] The control unit 15 may also be configured to periodically receive preset sinter quality indicators and / or energy consumption indicators input by an operator or transmitted from other production management systems. Based on these indicators, the control unit 15 adjusts the pre-stored target temperatures and oxygen concentrations for the sintering machine's ignition phase and pre-sintering stage.

[0052] In addition to the multi-point injection of the aforementioned ring-cooled exhaust gas, this system also includes a path for recycling the exhaust gas generated by the sintering machine itself. Specifically, the sintering exhaust gas drawn from the sintering exhaust gas outlet of the sintering machine first enters the multi-tube dust collector 16 for physical dust removal to remove most of the solid particulate matter; then, the initially purified sintering exhaust gas enters the waste heat recovery boiler 17, where its sensible heat is used to generate steam or heat other media, achieving cascade energy utilization; after cooling and waste heat recovery, the sintering exhaust gas is then pressurized by the circulating flue gas induced draft fan 18 to form circulating flue gas, which is then transported to the rear area of the circulating flue gas hood, i.e., the third injection area.

[0053] In the tail area of the circulating flue gas hood, the circulating flue gas that has been circulated back from the sintering machine itself and has undergone dust removal and waste heat recovery is mixed with the ring cooling exhaust gas drawn from the low-temperature oxygen-enriched section of the ring cooler and injected into this area. As the main gas reflux volume, the circulating flue gas helps to establish and maintain a certain micro-positive pressure in the tail area of the circulating flue gas hood, prevent the inhalation of external cold air, and form the basis for the macroscopic airflow flowing toward the head of the sintering machine. The low-temperature oxygen-enriched section ring cooling exhaust gas injected here as a supplement can further adjust the total gas volume and pressure in this area. The temperature of the flue gas circulating in the sintering itself has been significantly reduced after waste heat recovery, and the oxygen content is usually low, and the content of reducing gases such as CO may be high. The exhaust gas drawn from the low-temperature oxygen-enriched section of the ring cooler may have a slightly higher or equivalent temperature than the circulating flue gas, but the key is that it has a higher oxygen content. The combination of these two effectively increases the overall oxygen concentration of the mixed gas in the tail hood area, providing supplemental oxygen for any unburned fuel that may exist in the latter stages of the sintering process, promoting complete combustion and reducing CO emissions. It may also provide some insulation or slow cooling for the sintering bed in this area. Even recycled flue gas that has undergone waste heat recovery may still contain some unused waste heat and chemical latent heat. The addition of low-temperature, oxygen-rich, annular cooling exhaust gas, particularly the oxygen it carries, helps further release and utilize this latent heat in the latter stages of sintering. Simultaneously, the sensible heat of the annular cooling exhaust gas itself is also recovered.

[0054] An embodiment of the present invention further discloses a sintering flue gas circulation method based on matching the characteristics of ring-cooled exhaust gas, and the method comprises the following steps.

[0055] Step 1: The annular cooling exhaust gas is drawn out from the high-temperature section 41, the medium-temperature section 42 and the low-temperature oxygen-rich section 43 of the annular cooling machine 4 through the first, second and third annular cooling exhaust gas outlet circuits 5a, 5b and 5c respectively, and the temperature and oxygen content of each exhaust gas are monitored in real time through the online sensor component 6, and the data is transmitted to the control unit 15.

[0056] Step 2: The control unit 15 selects one or more ring-cooled exhaust gases with the best matching characteristics based on the predetermined target temperature and oxygen concentration of the current sintering stage, combined with the real-time exhaust gas characteristics monitored in step 1, and following the preset priority rules.

[0057] Step 3: The control unit 15 calculates the flow rate of the selected exhaust gas to be injected into the first injection area 9, the second injection area 10 and / or the third injection area 11, and controls the corresponding flow control components 8a, 8b, 8c to inject the selected exhaust gas according to the calculated flow rate.

[0058] Step 4: The control unit 15 controls the driving module 14 of each guide plate assembly 13 in the flow field control device 12 according to the characteristics and flow rate of the injected exhaust gas and the target flow field distribution requirements in the circulating fume hood 3, adjusts the opening of the guide plate component 131, and optimizes the distribution of the exhaust gas above the sintering material layer.

[0059] Step 5: The control unit 15 periodically receives the sinter quality and energy consumption indicators, and adjusts the predetermined target temperature and oxygen concentration accordingly.

[0060] By adopting the sintering flue gas circulation system and method based on the matching of the characteristics of the ring cooling exhaust gas provided by the present invention and comparing it with the existing traditional sintering flue gas circulation technology, the performance index comparison results are as follows: Figure 4 shown.

[0061] It can be seen that the present invention has a significant reduction in solid fuel unit consumption, indicating that the present invention effectively reduces the sintering process's dependence on external fuel by accurately matching and efficiently utilizing the heat energy contained in the annular cooling exhaust gas.

[0062] The present invention has significant improvements in sinter drum strength and sinter yield, indicating that the present invention improves the temperature uniformity of the sintering material layer by regulating the injected gas characteristics and the flow field in the hood, which directly promotes the stability of the sintering process and the improvement of the sintered ore quality.

[0063] The present invention has a significant reduction in flue gas SO2 emission concentration and flue gas NOx emission concentration, indicating that the present invention promotes the internal conversion and absorption of some pollutants by optimizing the combustion atmosphere and improving energy utilization efficiency.

[0064] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A sintering flue gas circulation system based on matching the characteristics of annular cooling exhaust gas, comprising a sintering machine (1), an ignition and heat preservation cover (2) and a circulating flue gas cover (3) arranged above the sintering machine (1), and an annular cooler (4) for cooling sintered ore, characterized in that: The sintering flue gas circulation system also includes: At least two mutually independent annular cooling waste gas outlet circuits (5), each annular cooling waste gas outlet circuit (5) is respectively connected to different segmented areas on the annular cooling machine (4) capable of outlet annular cooling waste gas having different temperature and oxygen content combination characteristics, and each annular cooling waste gas outlet circuit (5) is provided with an online sensor assembly (6), and the online sensor assembly (6) is used to monitor the temperature and oxygen content of the annular cooling waste gas outlet circuit (5) in real time; Annular cooling waste gas injection circuits (7) corresponding to the number of the annular cooling waste gas outlet circuits (5), each annular cooling waste gas injection circuit (7) respectively transports the annular cooling waste gas introduced from the annular cooling waste gas outlet circuit (5) as process gas directly to different injection zones above the sintering machine (1), the injection zones at least comprising a first injection zone (9) arranged inside the ignition heat preservation hood (2) and a second injection zone (10) arranged in the head region (31) of the circulating fume hood, and each annular cooling waste gas injection circuit (7) is provided with a flow control component (8); A flow field regulating device (12), the flow field regulating device (12) comprising at least one guide plate assembly (13) whose opening is controlled by a driving module (14), the guide plate assembly (13) being arranged inside the circulating fume hood (3); and A control unit (15), the control unit (15) being electrically connected to the online sensor assembly (6), the flow control assembly (8) and the drive module (14) of the flow field control device (12), and the control unit (15) being configured to execute the following control strategy: Based on the temperature and oxygen content of the ring cooling waste gas monitored in real time by the online sensor assembly (6), and in combination with the predetermined target temperature and predetermined target oxygen concentration during the ignition stage and the front end of the sintering process of the sintering machine (1), the operation of one or more corresponding ring cooling waste gas outlet circuits (5) and the ring cooling waste gas injection circuits (7) are selected and regulated; Controlling the flow control component (8) so that the selected ring-cooled exhaust gas is injected into the first injection area (9) and the second injection area (10) at a calculated flow rate; The opening of the guide plate assembly (13) of the flow field control device (12) is controlled according to the combined characteristics of the temperature and oxygen content of the injected annular cooling exhaust gas and the flow rate of the annular cooling exhaust gas.

2. The sintering flue gas circulation system based on ring cooling exhaust gas characteristic matching according to claim 1 is characterized in that: The injection zone further comprises a third injection zone (11) arranged in the middle or rear area of the circulating fume hood (3).

3. The sintering flue gas circulation system based on ring cooling exhaust gas characteristic matching according to claim 1 is characterized in that: There are multiple guide plate assemblies (13), and the multiple guide plate assemblies (13) are distributed along the length direction of the circulating fume hood (3) to form a guide plate array.

4. The sintering flue gas circulation system based on ring cooling exhaust gas characteristic matching according to claim 3 is characterized in that: The deflector assembly (13) is arranged in parallel along the longitudinal direction of the circulating smoke hood (3), and each of the deflector assemblies (13) comprises a plurality of deflector members (131) arranged at intervals along the extending direction of the column and independently rotatable around the side rotation axis thereof. The deflector members (131) are hinged to the circulating smoke hood (3), and the end portion of the other side of each deflector member (131) is fixedly connected to a driving gear (132). The inside of the circulating smoke hood (3) is provided with a long rack (133) arranged along the extending direction of the deflector assembly (13), corresponding to each of the deflector assemblies (13). The long rack (133) is connected to the deflector assembly ( The driving gears (132) of all the guide plate members (131) of the circulating fume hood (3) are meshed with each other, and at least one end of the long rack (133) is fixedly connected to the output end of the driving module (14) arranged outside the circulating fume hood (3). The driving module (14) causes the long rack (133) to generate linear reciprocating motion, thereby driving all the guide plates in the guide plate assembly (13) to rotate synchronously to adjust their deflection angles. In addition, the control unit (15) can control the driving modules (14) of different guide plate assemblies (13) respectively, so that the guide plates in any two adjacent guide plate assemblies (13) have relative deflection directions.

5. A sintering flue gas circulation method based on matching the characteristics of annular cooling exhaust gas, applied to a sintering flue gas circulation system comprising a sintering machine (1), an ignition and heat preservation cover (2) and a circulating flue gas cover (3) arranged above the sintering machine (1), and an annular cooler (4) for cooling sintered ore, characterized in that: The method comprises the following steps: The ring-cooled waste gas is led out from different segmented areas of the ring-cooled machine (4) capable of leading out ring-cooled waste gas having different temperature and oxygen content combination characteristics through at least two mutually independent ring-cooled waste gas leading-out circuits (5), and the temperature and oxygen content of the led out ring-cooled waste gas are monitored in real time using an online sensor assembly (6) provided on each ring-cooled waste gas leading-out circuit (5); The extracted annular cooling waste gas from each path is used as process gas and injected directly into different injection zones above the sintering machine (1) through the corresponding annular cooling waste gas injection circuit (7), wherein the injection zones include at least a first injection zone (9) inside the ignition and heat preservation cover (2) and a second injection zone (10) in the head area (31) of the circulating fume hood; The control unit (15) selects and adjusts the operation of one or more corresponding ring cooling waste gas outlet circuits (5) and ring cooling waste gas injection circuits (7) based on the temperature and oxygen content of the ring cooling waste gas monitored in real time by the online sensor assembly (6) and in combination with the predetermined target temperature and predetermined target oxygen concentration during the ignition stage and the front end of the sintering machine (1); Controlling the flow control component (8) provided on each annular cooling exhaust gas injection circuit (7) by means of a control unit (15) so that the selected annular cooling exhaust gas is injected into the first injection zone (9) and the second injection zone (10) at a calculated flow rate, respectively; The control unit (15) controls the opening of the guide plate assembly (13) of the flow field control device (12) disposed inside the circulating fume hood (3) according to the combined characteristics of the temperature and oxygen content of the injected annular cooling exhaust gas and the flow rate of the annular cooling exhaust gas.

6. The sintering flue gas circulation method based on ring cooling exhaust gas characteristic matching according to claim 5 is characterized in that: The injection zone also includes at least one third injection zone (11) in the middle or rear area of the circulating fume hood (3), and the control unit (15) selectively injects the ring cooling waste gas through the corresponding ring cooling waste gas injection circuit (7) and the flow control component (8) according to the predetermined process requirements of the middle and rear stages of sintering.

7. The sintering flue gas circulation method based on ring cooling exhaust gas characteristic matching according to claim 5 is characterized in that: The control unit (15) follows the following preset priority rules when selecting the best matching ring-cooled exhaust gas, firstly meeting the heat demand of the first injection zone (9) in the ignition insulation cover (2), and secondly meeting the oxygen content and preheating demand of the second injection zone (10) in the head area (31) of the circulating flue gas hood.

8. The sintering flue gas circulation method based on ring cooling exhaust gas characteristic matching according to claim 5 is characterized in that: The method further comprises the following steps: reading a periodically input preset sintered ore quality index and / or energy consumption index through a control unit (15), and adjusting a predetermined target temperature and a predetermined target oxygen concentration in the ignition stage and the front section of the sintering machine (1).

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