Carbon capture system of carbon-rich furnace

Abstract

The utility model discloses a carbon-rich furnace carbon capture system, the carbon-rich furnace carbon capture system includes carbon-rich furnace, coal injection duct, blast pipe, oxygen supply pipe and feed pipe, the coal injection duct is provided with a plurality of interval along the vertical direction and is used for introducing pulverized coal into the carbon-rich furnace, the blast pipe is used for introducing coal supply air into the carbon-rich furnace, the blast pipe is arranged above and below each coal injection duct, the oxygen supply pipe is used for supplying oxygen to the oxygen supply pipe, and the feed pipe is used for supplying oxygen to the oxygen supply pipe. The oxygen supply pipe is used for introducing pure oxygen into the carbon-rich furnace, the material supply pipe is used for introducing raw materials into the carbon-rich furnace, and the detection module is used for detecting temperatures and excess air coefficients of different areas of the carbon-rich furnace. According to the temperature and excess air coefficient feedback, the air volume of coal feeding air and the introduction amount of pulverized coal and / or pure oxygen in the corresponding area are adjusted, so that the temperature in the area is recovered to the preset temperature, impurity gas in smoke exhausted by the carbon-rich furnace is reduced, and the energy consumption of the furnace is reduced. Multi-area air supply combustible materials are gathered in a carbon-rich furnace, and the local part of the carbon-rich furnace has a higher combustion speed, so that the local part of the carbon-rich furnace is overheated and crusts.

Description

Technical Field

[0001] The utility model relates to the technical field of carbon capture in the cement industry, in particular to a carbon capture system for a rich carbon furnace. Background Art

[0002] Most of the existing industrialized carbon capture methods are amine method or membrane method. After the amine solution absorbs CO2, the CO2 is released by heating, which requires additional energy consumption and high capture cost. The CO2 concentration obtained by membrane method is relatively low and needs further purification, and the process is relatively complex. The service life and cost of the membrane still need to be further improved. In the cement industry, high-concentration oxygen is used as a combustion aid, and oxygen and fuel burn in a rich carbon furnace to generate high-concentration CO2, and the carbon source is directly captured and enriched. However, a large amount of heat is released during the combustion of fuel and high-concentration oxygen, and the inside of the rich carbon furnace is prone to crusting or damage due to excessive heat radiation intensity.

[0003] In the related art, when the temperature in a certain area of the rich carbon furnace is overheated, usually the oxygen flow rate or the fuel input amount is reduced to slow down the rate of heat release from fuel combustion, thereby reducing the temperature of the rich carbon furnace in this area. However, since different areas inside the rich carbon furnace are interconnected and the combustion of fuel has a linkage effect, there is fuel shortage or excessive fuel that is not burned out in a certain area of the rich carbon furnace, resulting in more other types of gases in the flue gas finally generated by the rich carbon furnace, which is not conducive to the later purification of CO2. Summary of the Invention

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. For this reason, the utility model provides a carbon capture system for a rich carbon furnace, which can reduce the influence of heat released by fuel combustion on the rich carbon furnace and reduce the risk of local overheating and damage of the rich carbon furnace.

[0005] According to the carbon capture system for a rich carbon furnace provided by the embodiment of the utility model, it includes:

[0006] A rich carbon furnace;

[0007] A plurality of coal injection pipes are arranged at intervals in the vertical direction. The coal injection pipes are connected to the rich carbon furnace and are used for introducing pulverized coal into the rich carbon furnace;

[0008] A plurality of air supply pipes are arranged at intervals in the vertical direction. The air supply pipes are connected to the rich carbon furnace and are used for introducing coal delivery air into the rich carbon furnace. The air supply pipes are arranged above and below each coal injection pipe;

[0009] An oxygen supply pipe is connected to the rich carbon furnace and is used for introducing pure oxygen into the rich carbon furnace;

[0010] A feed pipe is connected to the rich carbon furnace and is used for introducing raw meal into the rich carbon furnace;

[0011] A detection module for detecting the temperature and excess air coefficient in different areas of the carbon-rich furnace.

[0012] The carbon capture system of the carbon-rich furnace according to the embodiment of the present invention has at least the following beneficial effects:

[0013] The detection module in the present invention can detect the temperature and excess air coefficient in different areas of the carbon-rich furnace, and can adjust the air volume of the coal-feeding air, the feeding amount of pulverized coal and / or pure oxygen in the corresponding area according to the feedback of the temperature and excess air coefficient in different areas of the carbon-rich furnace, so that the temperature in this area is restored to the preset temperature, and the fuels in different areas of the carbon-rich furnace can all burn under a suitable combustion environment, reducing the probability of fuel shortage or unburned excess fuel in the carbon-rich furnace, reducing the impurity gases in the flue gas discharged from the carbon-rich furnace, increasing the CO2 concentration in the flue gas, facilitating the later purification of CO2. In addition, multi-area air supply makes the position where the pulverized coal enters the carbon-rich furnace relatively dispersed, avoiding the accumulation of fuel in the carbon-rich furnace and the local high combustion speed of the carbon-rich furnace, resulting in local overheating and scaling of the carbon-rich furnace.

[0014] According to some embodiments of the present invention, the carbon capture system of the carbon-rich furnace further includes a carbon collection pipe for receiving the CO2 discharged from the carbon-rich furnace, and any one of the air supply pipes is connected to the carbon collection pipe and supplies CO2 into the carbon-rich furnace.

[0015] According to some embodiments of the present invention, the carbon capture system of the carbon-rich furnace further includes an output pipe and a main pipe. The carbon collection pipe is connected to the output pipe and the main pipe. Each air supply pipe is connected to the main pipe. A fan is provided on the main pipe and the output pipe. The output pipe is used to discharge CO2, and the fan is used to introduce CO2 into the main pipe or the output pipe. A valve is provided on each air supply pipe.

[0016] According to some embodiments of the present invention, one of the air supply pipes is connected to the bottom of the carbon-rich furnace and supplies coal-feeding air upward into the carbon-rich furnace.

[0017] According to some embodiments of the present invention, the carbon-rich furnace is provided with a plurality of air inlets arranged circumferentially, and each air inlet is communicated with at least one of the air supply pipes.

[0018] According to some embodiments of the present invention, the feeding pipe is located between adjacent coal injection pipes.

[0019] According to some embodiments of the present utility model, the carbon-rich furnace is successively provided with a first combustion zone, a second combustion zone, and a third combustion zone from bottom to top. At least one oxygen supply pipe is connected to each of the first combustion zone, the second combustion zone, and the third combustion zone. At least one coal injection pipe and one air supply pipe are connected to each of the first combustion zone and the second combustion zone. The feed pipe is connected to the first combustion zone.

[0020] According to some embodiments of the present utility model, the carbon capture system of the carbon-rich furnace further includes a denitration pipeline, which is connected to the smoke outlet at the top of the carbon-rich furnace, and an ammonia injection module is provided in the denitration pipeline.

[0021] According to some embodiments of the present utility model, the carbon capture system of the carbon-rich furnace further includes a cyclone, which is connected to the outlet of the denitration pipeline, and the cyclone separates the gas-solid mixture discharged from the cyclone.

[0022] According to some embodiments of the present utility model, the carbon capture system of the carbon-rich furnace further includes a heat exchange boiler, which is connected to the gas outlet of the cyclone and is used for cooling the flue gas and collecting the heat of the flue gas.

[0023] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present utility model. Description of the Drawings

[0024] The following further describes the present utility model in conjunction with the drawings and embodiments, where:

[0025] Figure 1 is a schematic diagram of an embodiment of the carbon capture system of the carbon-rich furnace of the present utility model;

[0026] Figure 2 is a signal flow diagram of an embodiment of the carbon capture system of the carbon-rich furnace.

[0027] Reference Signs:

[0028] Carbon-rich furnace 100, coal injection pipe 101, air supply pipe 102, oxygen supply pipe 103, feed pipe 104, carbon collection pipe 105, output pipe 106, main pipe 107, fan 108, first combustion zone 110, second combustion zone 120, third combustion zone 130; Denitration pipeline 200; Cyclone 300; Heat exchange boiler 400; Dust collector 500; Oxygen supply device 600; Detection module 700; Control module 800. Detailed Embodiments

[0029] Embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation of the present utility model.

[0030] In the description of the present utility model, it should be understood that with respect to the orientation description, such as the orientations or positional relationships indicated by up, down, front, back, left, right, etc., are based on the orientations or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present utility model.

[0031] In the description of the present utility model, the meaning of "several" is more than one, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the recited number, and understandings such as "above", "below", "within", etc. include the recited number. If there is a description of "first", "second", etc., it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0032] In the description of the present utility model, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection", etc. should be understood in a broad sense. Those skilled in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0033] In the description of the present utility model, the descriptions referring to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0034] One of the sources of CO2 generated during the combustion of cement raw materials is the carbon oxidation during the combustion of fuel (such as coal powder) to generate carbon dioxide. The second source is the high-temperature decomposition of carbonates in raw materials (such as limestone) to generate carbon dioxide. When air is used as the combustion-supporting gas, due to the large proportion of nitrogen in the air, there are a large number of nitrogen oxides in the flue gas formed by the combustion of fuel, resulting in a low concentration of carbon dioxide. In addition, carbon dioxide needs to be purified by other methods such as denitrification to remove nitrogen oxides in order to reduce the proportion of nitrogen oxides in the flue gas and increase the concentration of carbon dioxide. Replacing air with oxygen-enriched or pure oxygen and using high-concentration oxygen to burn with fuel can greatly reduce the nitrogen in the combustion atmosphere and the nitrogen oxides generated by the combustion of nitrogen, increase the CO2 concentration in the flue gas of the cement industry, reduce the cost of CO2 purification in the later stage, and thus improve the CO2 capture efficiency. However, as an oxidant with extremely high chemical activity, oxygen undergoes a high-intensity combustion reaction with the fuel in the carbon-rich furnace, resulting in local overheating and excessive heat radiation of the carbon-rich furnace, causing the material to melt and liquefy, and it is easy to cause crusting and damage in the carbon-rich furnace. In the related art, when the temperature in a certain area of ​​the carbon-rich furnace is overheated, the oxygen flow rate is usually reduced or the fuel flow rate is reduced to slow down the rate of heat release from fuel combustion, thereby reducing the temperature of the carbon-rich furnace in this area. However, since different areas in the carbon-rich furnace are interconnected, the combustion of the fuel has a linkage effect, resulting in insufficient fuel or excessive fuel and unburned fuel in a certain area of ​​the carbon-rich furnace, resulting in the presence of more other types of gases in the flue gas finally generated by the carbon-rich furnace, which is not conducive to the later purification of CO2.

[0035] Reference Figure 1 and Figure 2, the present utility model provides a carbon capture system for a rich carbon furnace (hereinafter referred to as the system), which is used to collect CO2 in the industrial tail gas generated during the processing of cement raw materials, and at the same time reduce the impact of the heat released by the high-intensity combustion of fuel with pure oxygen in the rich carbon furnace on the rich carbon furnace, reduce the risk of local overheating and damage of the rich carbon furnace, and enable the fuel to burn fully in the rich carbon furnace. The system includes a rich carbon furnace 100, a coal injection pipe 101, an air supply pipe 102, an oxygen supply pipe 103 and a feeding pipe 104. The coal injection pipe 101, the air supply pipe 102, the oxygen supply pipe 103 and the feeding pipe 104 are all connected to the rich carbon furnace 100. The oxygen supply pipe 103 is used to introduce pure oxygen into the rich carbon furnace 100, the feeding pipe 104 is used to introduce cement raw meal into the rich carbon furnace 100, the air supply pipe 102 is used to introduce coal conveying air into the rich carbon furnace 100, and the coal injection pipe 101 is used to introduce pulverized coal into the rich carbon furnace 100. The system also includes a detection module 700, which is used to detect the temperature and excess air coefficient in different areas of the rich carbon furnace 100. The detection module 700 is not limited to a multi-device combination structure set as a gas concentration sensor and a temperature sensor; the system also includes a control module 800, which is communicatively connected to the detection module 700 and adjusts the pulverized coal input amount in the coal injection pipe 101, the pure oxygen input amount in the oxygen supply pipe 103, the air volume of the coal conveying air in the air supply pipe 102, etc. according to the detection information of the detection module 700.

[0036] The coal injection pipe 101 and the air supply pipe 102 are both provided with a plurality of intervals along the vertical direction. The coal injection pipe 101 introduces pulverized coal into the rich carbon furnace 100 at different heights. In addition, an air supply pipe 102 is provided above and below each coal injection pipe 101. After the coal conveying air enters the rich carbon furnace 100, it can be quickly mixed with the pulverized coal and dispersed in the rich carbon furnace 100 under the drive of the coal conveying air, avoiding the accumulation of combustibles in the rich carbon furnace 100 and reducing the risk of local overheating, high-temperature scaling and damage of the rich carbon furnace 100.

[0037] The fuel process of the fuel in the rich carbon furnace 100 is that pure oxygen, pulverized coal and raw meal are introduced into the rich carbon furnace 100. After the pulverized coal enters the rich carbon furnace 100, it is mixed with the coal conveying air and dispersed under the drive of the coal conveying air. At the same time, it continues to flow upward following the coal conveying air. The pulverized coal continues to burn during the flowing process, providing heat for the decomposition of carbonate raw meal and generating CO2. Moreover, the pulverized coal and carbonate raw meal continue to move upward along the rich carbon furnace 100 under the drive of the coal conveying air and continue to burn and decompose in a suspended state during the flowing process. In the long extension space of the rich carbon furnace 100, the decomposition of carbonate raw meal and the combustion of pulverized coal are more sufficient, and the generated flue gas mainly composed of CO2 is discharged from the top of the rich carbon furnace 100.

[0038] In the present utility model, the temperature and excess air coefficient in different regions of the rich carbon furnace 100 are detected by a detection module. According to the temperature feedback in different regions of the rich carbon furnace 100, the air volume of the coal feeding air in the corresponding region is changed, so that the temperature in the region is restored to the preset temperature. Moreover, the multi-region air supply makes the position where the pulverized coal enters the rich carbon furnace 100 relatively dispersed, avoiding the accumulation of fuel in the rich carbon furnace 100 and the high combustion speed in a local area of the rich carbon furnace 100, which may cause local overheating and scaling of the rich carbon furnace 100. And while adjusting the air supply volume, according to the feedback of the excess air coefficient in different regions of the rich carbon furnace 100, the input amount of pulverized coal and / or pure oxygen in the corresponding region is changed, so that the fuel in different regions of the rich carbon furnace 100 can burn under a suitable combustion environment, reducing the probability of fuel shortage or unburned fuel excess in the rich carbon furnace 100, reducing the impurity gas in the flue gas discharged from the rich carbon furnace 100, and increasing the CO2 concentration in the flue gas, which is convenient for the subsequent purification of CO2.

[0039] Exemplarily, when the temperature in a certain region of the rich carbon furnace 100 is higher than the preset temperature, it indicates that there is an overburning situation in this region of the rich carbon furnace 100. Then, the air volume of the coal feeding air introduced into this region can be increased to increase the movement speed of the material in this region, reduce the combustion amount of the fuel in this region, and reduce the heat generated by the fuel combustion, so that the temperature in this region is restored to the preset temperature. If the temperature in this region is too low, the air volume of the coal feeding air introduced into this region can be correspondingly reduced to restore the temperature in this region to the preset temperature. When the excess air coefficient is greater than the preset value, it indicates that the oxygen supply is sufficient and the pulverized coal can burn sufficiently. If there is also a situation where the temperature in this region is higher than the preset temperature, the input amount of pure oxygen can be appropriately reduced to enable the fuel in this region to burn under a suitable combustion environment, reducing the heat released by the high-intensity combustion of the pulverized coal with pure oxygen as the combustion aid, so as to restore the temperature in this region to the preset temperature. When the excess air coefficient is greater than the preset value and there is also a situation where the temperature in this region is lower than the preset temperature, the input amount of pulverized coal can be appropriately increased. On the one hand, the pulverized coal can burn in an oxygen-rich environment, and on the other hand, the temperature in this region can be increased to restore the temperature in this region to the preset temperature. Similarly, when the excess air coefficient is less than the preset value, it indicates that the oxygen supply is insufficient and the pulverized coal burns incompletely. If there is also a situation where the temperature in this region is too low, the input amount of pure oxygen can be increased; when the excess air coefficient is less than the preset value and there is also a situation where the temperature in this region is higher than the preset temperature, the input amount of pulverized coal can be appropriately reduced.

[0040] The decomposition of carbonate raw meal is the main source of the generated CO2. Improving the decomposition efficiency and degree of carbonate raw meal is beneficial to increasing the CO2 concentration in the flue gas. The flue gas generated by combustion in the carbon-rich furnace 100 is discharged from the top of the carbon-rich furnace 100. The carbon-rich furnace 100 is integrally set as a furnace body in an upright and slender shape, so that the materials entering the carbon-rich furnace 100 are in a suspended state during the long extension process, and the carbonate raw meal can be decomposed fully and rapidly. The decomposition of the carbonate raw meal can form an alkaline environment in the carbon-rich furnace 100. Under high temperature and alkaline environment, the SO2 generated by the combustion of pulverized coal can react with the decomposition products of the raw meal and be self-adsorbed in the materials, reducing the amount of SO2 entering the flue gas at the tail of the carbon-rich furnace 100 and increasing the CO2 concentration in the flue gas.

[0041] It can be understood that since an air supply pipe 102 is provided below each coal injection pipe 101, after the pulverized coal enters the carbon-rich furnace 100, it is mixed with the coal supply air and dispersed under the drive of the coal supply air. At the same time, it continues to flow upward following the coal supply air. The pulverized coal continues to burn during the flowing process, providing heat for the decomposition of the carbonate raw meal and generating CO2. Moreover, the pulverized coal and the carbonate raw meal continue to move upward along the carbon-rich furnace 100 under the drive of the coal supply air, and continue to burn and decompose in a suspended state during the flowing process. In the long extension space of the carbon-rich furnace 100, the decomposition of the carbonate raw meal and the combustion of the pulverized coal are more sufficient, and the generated flue gas mainly composed of CO2 is discharged from the top of the carbon-rich furnace 100.

[0042] In an embodiment, one of the air supply pipes 102 is connected to the bottom of the carbon-rich furnace 100. The coal supply air discharged from the air supply pipe 102 flows upward after entering the carbon-rich furnace 100, so that the raw meal and pulverized coal entering the carbon-rich furnace 100 have an upward flowing state under the action of the coal supply air, and a suspended calcination reaction flow field is formed in the carbon-rich furnace 100. By adjusting the air volume and air speed of the coal supply air introduced into the carbon-rich furnace 100 through different air supply pipes 102, the suspended flow speed of the materials in the carbon-rich furnace 100 is stabilized, and the decomposition efficiency of the carbonate raw meal and the burnout rate of the pulverized coal are improved; in addition, an upward air flow is provided through the air supply pipe 102 to the carbon-rich furnace 100, so that the materials continue to move upward following the coal supply air, avoiding material settlement and crust formation.

[0043] The air supply pipes 102 and the coal injection pipes 101 are arranged alternately in the vertical direction, that is, one air supply pipe 102 is provided between adjacent coal injection pipes 101. On the one hand, the coal supply air drives the materials in the lower layer to flow upward, mixes with the materials in the upper layer and reacts; on the other hand, it pushes the materials in the upper layer to continue to flow upward to form a continuous and upward suspended flow field in the carbon-rich furnace 100.

[0044] Furthermore, the carbon-rich furnace 100 is provided with a plurality of air inlets arranged circumferentially, and each air inlet is communicated with at least one air supply pipe 102, so that the air supply points of the air supply pipes 102 are more dispersed. After the pulverized coal enters the carbon-rich furnace 100, it is quickly dispersed by the coal supply air at different positions, which can further improve the dispersion degree of the pulverized coal, make the pulverized coal burn evenly in the carbon-rich furnace 100, and further reduce the risk of local overheating and damage of the carbon-rich furnace 100. It can be understood that the coal injection pipe 101, the oxygen supply pipe 103 and the feeding pipe 104 can all be arranged to feed materials from different positions in the circumferential direction of the carbon-rich furnace 100, so that the materials entering the carbon-rich furnace 100 are dispersed to the greatest extent, the materials are fully mixed, and the combustion of the fuel and the decomposition of the carbonate are more thorough; taking the oxygen supply pipe 103 and the air supply pipe 102 as an example, the pipe ends of the oxygen supply pipe 103 and the air supply pipe 102 can both be connected with small spraying devices, and pure oxygen and the coal supply air can be sprayed into the interior of the carbon-rich furnace 100 at multiple points through the small spraying devices, so that the coal supply air and pure oxygen enter the carbon-rich furnace 100 at a certain speed, are dispersed in the carbon-rich furnace 100, and can be fully mixed with the pulverized coal.

[0045] In addition, the air supply pipe 102 can be arranged to supply air tangentially to the carbon-rich furnace 100 to form a swirling airflow in the carbon-rich furnace 100 and continuously push the materials, so as to maximize the dispersion of the pulverized coal in the carbon-rich furnace 100. On the one hand, the materials are continuously pushed upward to avoid material settlement and crust formation. On the other hand, it avoids local overheating in the carbon-rich furnace 100, resulting in ash phase change, deposition and then crust formation.

[0046] The system is also provided with a carbon collection pipe 105, which is connected to the smoke outlet at the top of the carbon-rich furnace 100. The high-concentration CO2 formed after the gas-solid separation of the flue gas generated in the carbon-rich furnace 100 is discharged into the carbon collection pipe 105. Any air supply pipe 102 is connected to the carbon collection pipe 105 and CO2 is introduced into the carbon-rich furnace 100.

[0047] Furthermore, the carbon collection pipe 105 is connected to an output pipe 106 and a main pipe 107. Each air supply pipe 102 is communicated with the main pipe 107. A fan 108 is arranged on the main pipe 107 and the output pipe 106. The fan 108 is used for drawing air so that CO2 is discharged into the main pipe 107 or the output pipe 106, and the CO2 is discharged and collected from the output pipe 106. It can be understood that a valve can be arranged on each air supply pipe 102. When it is necessary to change the air volume of the coal supply air, the air volume introduced into the corresponding air supply pipe 102 by the fan 108 can be changed by adjusting the opening degree of the valve.

[0048] In addition, the feed pipe 104 is located between adjacent coal injection pipes 101. After the raw meal enters the rich carbon furnace 100, it receives the heat released by the combustion of the pulverized coal above and the heat released by the combustion of the pulverized coal below, and then decomposes rapidly. Since the air supply pipes 102 are located on the upper and lower sides of the coal injection pipes 101, both the raw meal and the pulverized coal entering the rich carbon furnace 100 are dispersed by the airflows of the coal delivery air and oxygen, and a stable calcination suspension length is formed in the rich carbon furnace 100, and sufficient decomposition and combustion occur.

[0049] The rich carbon furnace 100 is successively provided with a first combustion zone 110, a second combustion zone 120 and a third combustion zone 130 from bottom to top. The coal delivery air is respectively introduced into the first combustion zone 110 and the second combustion zone 120, and pure oxygen is respectively introduced into the first combustion zone 110, the second combustion zone 120 and the third combustion zone 130. At least pulverized coal and raw meal are introduced into the first combustion zone 110. During the combustion process of the fuel in the rich carbon furnace 100, by adjusting the input amount of pure oxygen, an oxygen-deficient combustion environment can be formed in the first combustion zone 110, an oxygen-starved combustion environment can be formed in the second combustion zone 120, and an oxygen-rich combustion environment can be formed in the third combustion zone 130.

[0050] Specifically, less pure oxygen is introduced into the first combustion zone 110, and the excess air coefficient in the first combustion zone 110 is less than 1, so that the fuel burns in an oxygen-deficient environment, reducing the combustion speed and temperature of the pulverized coal, inhibiting the formation of nitrogen oxides during the combustion of the pulverized coal. The pulverized coal decomposes in the oxygen-deficient environment and generates reducing agents such as CO, HCN, and NHx. The reducing agents can flow to the second combustion zone 120 under the action of the coal delivery air, and a strong reducing environment is constructed in the second combustion zone 120. The second combustion zone 120 forms the main combustion zone. Further pulverized coal and pure oxygen are provided in the second combustion zone 120 to form an oxygen-starved atmosphere, and the pulverized coal burns in an oxygen-starved state, further inhibiting the formation of nitrogen oxides during the combustion of the pulverized coal. The reducing agents can react with the nitrogen oxides in the flue gas at the tail of the rich carbon furnace 100, reducing the nitrogen oxides to pollution-free inert gases such as nitrogen, and reducing the concentration of nitrogen oxides in the flue gas. Only pure oxygen is provided in the third combustion zone 130, so that the pulverized coal burns completely under oxygen-rich conditions, ensuring that the fuel is completely burned, and providing a large amount of heat for the decomposition of the raw meal, so that the raw meal is completely decomposed. On the premise of ensuring that the pulverized coal is completely burned, the concentration of nitrogen oxides in the flue gas is reduced, and the denitrification efficiency is improved. By forming a gradient-distributed combustion environment in the rich carbon furnace 100, the pulverized coal decomposes in an oxygen-starved environment to generate reducing agents, which react with the nitrogen oxides in the flue gas, reducing the nitrogen oxides to pollution-free gases such as nitrogen, and inhibiting the formation of self-fuel-type nitrogen oxides during the combustion of the pulverized coal, realizing the reduction of nitrogen oxides during the carbon collection process and increasing the concentration of CO2 in the flue gas.

[0051] At least one oxygen supply pipe 103 is connected to each of the first combustion zone 110, the second combustion zone 120, and the third combustion zone 130. At least one coal injection pipe 101 and one air supply pipe 102 are connected to both the first combustion zone 110 and the second combustion zone 120. The feed pipe 104 is connected to the first combustion zone 110, and raw meal, pulverized coal, and pure oxygen are introduced into the first combustion zone 110. During the combustion process of the fuel in the rich carbon furnace 100, by adjusting the amount of pure oxygen introduced, an oxygen-deficient combustion environment can be formed in the first combustion zone 110, an oxygen-starved combustion environment can be formed in the second combustion zone 120, and an oxygen-rich combustion environment can be formed in the third combustion zone 130.

[0052] As a good combustion promoter, pure oxygen reacts violently after ignition and generates a large amount of heat. The raw meal is fed into the rich carbon furnace 100 from the first combustion zone 110. During the decomposition process of the raw meal, heat is absorbed, keeping the temperature in the first combustion zone 110 within a reasonable range to allow the continuous combustion of the pulverized coal and prevent sintering and crust formation due to continuous heat output. Pure oxygen is introduced into the first combustion zone 110, the second combustion zone 120, and the third combustion zone 130. The amount of pure oxygen introduced can be adjusted in real time according to the feedback of the excess air coefficient in different combustion zones to form a gradient combustion environment in the rich carbon furnace 100. In addition, the pulverized coal is fed into the rich carbon furnace 100 in the first combustion zone 110 and the second combustion zone 120. Both the first combustion zone 110 and the second combustion zone 120 can provide heat for the decomposition of the raw meal to ensure complete decomposition of the raw meal. Unburned pulverized coal, CO, etc. in the first combustion zone 110 and the second combustion zone 120 can continue to burn fully under the oxygen-rich regulation of the third combustion zone 130.

[0053] In addition, the oxygen supply pipe 103 connected to the first combustion zone 110 is connected to the bottom of the rich carbon furnace 100. One of the air supply pipes 102 is connected to the bottom of the rich carbon furnace 100 and feeds the coal delivery air upward into the rich carbon furnace 100. On the one hand, the pure oxygen and the coal delivery air flow upward together, causing the raw meal and the pulverized coal to form an upward flow state in the rich carbon furnace 100, constructing a reaction flow field for suspension calcination, enabling the material to continuously flow upward and be discharged from the top of the rich carbon furnace 100. On the other hand, it makes the pulverized coal, raw meal, and pure oxygen fully mixed to form a solid-gas mixture, ensuring complete combustion of the pulverized coal, full decomposition of the raw meal, and full dispersion of the solid-gas mixture to avoid the aggregation of combustibles and cause local high temperatures in the rich carbon furnace 100.

[0054] The smoke outlet at the top of the carbon-rich furnace 100 is connected to a denitration pipeline 200. The flue gas generated in the carbon-rich furnace 100 is discharged into the denitration pipeline 200. An SNCR ammonia water injection module is set in part of the denitration pipeline 200 for denitration. Ammonia water is sprayed into the denitration pipeline 200 by a spray gun to further remove nitrogen oxides in the flue gas. The denitration pipeline 200 is provided with a sensor for collecting the content of nitrogen oxides. According to the change of the nitrogen oxide content, the ammonia injection position and the ammonia injection amount are adjusted in real time. In addition, the denitration efficiency and denitration uniformity can be improved, and the ammonia water consumption, ammonia escape and operation cost can be reduced by configuring a flow regulating valve group, changing the spray gun arrangement position, etc.

[0055] The denitration pipeline 200 is connected to a cyclone 300 at the back. The flue gas after denitration enters the cyclone 300. The gas-solid mixture in the flue gas is separated in the cyclone 300. The gas mainly composed of... is discharged from the top of the cyclone 300. The solid particulate matter (such as the decomposed raw meal) is returned to the cement kiln preheater for further utilization to realize the dual recovery of solid and gas. The flue gas discharged from the cyclone 300 enters a heat exchange boiler 400 for cooling. By cooling the flue gas, the temperature of the flue gas is controlled within the conveying capacity of the system fan to meet the heat resistance requirements of subsequent process equipment. And the flue gas generates steam through heat exchange in the heat exchange boiler 400, which can be used in the waste heat power generation system of the cement production line to realize energy recovery. The cyclone 300 is connected to a dust collector 500 through a pipeline. The cooled flue gas is introduced into the dust collector 500. The dust collector 500 filters the flue gas, intercepts impurities such as dust and particulate matter in the flue gas, purifies and cleans the flue gas, and improves the CO2 purity. The dust collector 500 is connected to a carbon collection pipe 105. The purified flue gas contains a high concentration of CO2. The flue gas is introduced into the carbon collection pipe 105. Part of the flue gas is discharged through an output pipe 106 connected to the carbon collection pipe 105 to produce liquid CO2, dry ice, etc., to realize energy conservation and emission reduction. Part of the flue gas is returned to the carbon-rich furnace 100 again through an air supply pipe 102.

[0056] The upper half of the carbon-rich furnace 100 is set as a cylindrical shape to avoid material accumulation and even crust formation at the side walls and corners of the carbon-rich furnace 100. The lower half of the carbon-rich furnace 100 is set as a reduced-opening structure, that is, the cross-sectional area of the carbon-rich furnace 100 gradually decreases from top to bottom, which helps the airflow to drive the material movement in the carbon-rich furnace 100, promotes the dispersion, suspension and mutual mixing of the material, and is beneficial to the combustion and decomposition processes. The bottom of the carbon-rich furnace 100 is also provided with an ash discharge port for removing impurities accumulated at the bottom of the carbon-rich furnace 100, such as ash residues generated after coal powder combustion and carbonate raw meal decomposition, to avoid ash residue blocking the air inlet channels of the oxygen supply pipe 103 and the air supply pipe 102.

[0057] The system further includes an oxygen supply device 600 for preparing high-concentration oxygen. The oxygen supply pipe 103 is connected to the oxygen supply device 600, and the high-concentration oxygen is further transported to the oxygen supply pipe 103. Exemplarily, the oxygen supply device 600 purifies oxygen by the cryogenic air separation method. Air is introduced into the oxygen supply device 600. By utilizing the different boiling points of oxygen and nitrogen in the air, the air is first compressed and expanded to lower the temperature until it is liquefied. Then, by taking advantage of the different vaporization and boiling points of nitrogen and oxygen, nitrogen with a lower boiling point is more likely to vaporize than oxygen, so that high-concentration oxygen is separated from the air.

[0058] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the relevant art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A carbon capture system for a rich carbon furnace, characterized in that, Comprising: Rich carbon furnace; Coal injection pipes, a plurality of which are arranged at intervals in the vertical direction, the coal injection pipes are connected to the rich carbon furnace and are used for introducing pulverized coal into the rich carbon furnace; Air supply pipes, a plurality of which are arranged at intervals in the vertical direction, the air supply pipes are connected to the rich carbon furnace and are used for introducing coal supply air into the rich carbon furnace, and an air supply pipe is provided above and below each coal injection pipe; Oxygen supply pipe, connected to the rich carbon furnace and used for introducing pure oxygen into the rich carbon furnace; Feeding pipe, connected to the rich carbon furnace and used for introducing raw materials into the rich carbon furnace; Detection module, used for detecting the temperature and excess air coefficient in different areas of the rich carbon furnace.

2. The carbon capture system of the carbon-rich furnace according to claim 1, characterized in that, The rich carbon furnace carbon capture system further includes a carbon collection pipe, the carbon collection pipe is used for receiving CO2 discharged from the rich carbon furnace, and any one of the air supply pipes is connected to the carbon collection pipe and introduces CO2 into the rich carbon furnace.

3. The carbon capture system of the carbon-rich furnace according to claim 2, characterized in that, The rich carbon furnace carbon capture system further includes an output pipe and a main pipe, the carbon collection pipe is connected to the output pipe and the main pipe, each air supply pipe is connected to the main pipe, a fan is provided on the main pipe and the output pipe, the output pipe is used for discharging CO2, the fan is used for introducing CO2 into the main pipe or the output pipe, and a valve is provided on each air supply pipe.

4. The carbon capture system for a carbon-rich furnace according to claim 1, wherein One of the air supply pipes is connected to the bottom of the rich carbon furnace and introduces coal supply air into the rich carbon furnace upward.

5. The carbon capture system of the carbon-rich furnace according to claim 1, wherein The rich carbon furnace is provided with a plurality of air inlets arranged circumferentially, and each air inlet is communicated with at least one air supply pipe.

6. The carbon capture system for a carbon-rich furnace according to claim 1, wherein The feeding pipe is located between adjacent coal injection pipes.

7. The carbon capture system for a rich carbon furnace according to any one of claims 1 to 6, characterized in that, The rich carbon furnace is successively provided with a first combustion zone, a second combustion zone and a third combustion zone from bottom to top, at least one oxygen supply pipe is connected to each of the first combustion zone, the second combustion zone and the third combustion zone, at least one coal injection pipe and one air supply pipe are connected to each of the first combustion zone and the second combustion zone, and the feeding pipe is connected to the first combustion zone.

8. The carbon capture system for a carbon-rich furnace according to any one of claims 1 to 6, characterized in that, The rich carbon furnace carbon capture system further includes a denitration pipeline, the denitration pipeline is connected to the smoke outlet at the top of the rich carbon furnace, and an ammonia water injection module is provided in the denitration pipeline.

9. The carbon capture system for a carbon-rich furnace according to claim 8, characterized in that, The rich carbon furnace carbon capture system further includes a cyclone, the cyclone is connected to the outlet of the denitration pipeline, and the cyclone separates the gas-solid mixture discharged from the cyclone.

10. The carbon capture system of the carbon-rich furnace according to claim 9, characterized in that, The rich carbon furnace carbon capture system further includes a heat exchange boiler, the heat exchange boiler is connected to the gas outlet of the cyclone and is used for cooling the flue gas and collecting the heat of the flue gas.

Images