A full-process CO2 collaborative treatment process system and control method

Abstract

The present application relates to a full-process CO coordinated governance process system and control method. Each wind box of the sintering machine is connected to a wind box flue for exhausting flue gas. The front-end internal circulation system includes an internal circulation main flue, an internal circulation dust collector and a waste heat recovery device. The flue gas from each wind box flue is merged into a circulating flue gas through the internal circulation main flue, enters the internal circulation dust collector and the waste heat recovery device, and returns to the sintering material surface through the gas collecting hood to participate in sintering again; the terminal purification system includes an external exhaust flue gas main flue, an external exhaust flue gas dust collector, a desulfurization reaction device and a NOx-CO reaction device; the flue gas from each wind box flue is merged into an external exhaust flue gas through the external exhaust flue gas main flue, enters the external exhaust flue gas dust collector, the desulfurization reaction device and the NOx-CO reaction device; the dynamic control system adjusts the sintering flue gas flow opening in the wind box flue to maintain a stable CO concentration in the flue gas entering the terminal purification system. The process system of the present application can ensure the efficient and stable operation of the system and achieve stable and standard emission of CO concentration in the outlet flue gas.

Description

Technical Field

[0001] The present application relates to the field of metallurgical environmental protection technology, and in particular to a full-process CO2 collaborative governance process system and control method. Background Art

[0002] At present, the total amount of CO emitted by steel sintering machines nationwide reaches 50 to 60 million tons per year. Due to the large amount of sintering flue gas, complex composition, large fluctuation range of temperature and CO content, it is complicated to control the CO in sintering flue gas. The sintering process is the "hardest hit area" of CO emissions in the steel industry. The causes of CO emissions include incomplete combustion of sintering materials, Bodo reaction (reaction of carbon and carbon dioxide), direct reduction of iron oxide, water-gas reaction and other chemical reactions.

[0003] The existing CO removal technology for steel sintering flue gas has the following problems:

[0004] The flue gas circulation system has low efficiency and poor adaptability to working conditions, which easily affects the output and quality of sintered ore: pollutants are reduced only through flue gas circulation, the amount of circulating flue gas is limited, and the content of flue gas pollutants in each bellows fluctuates greatly, making the removal efficiency of flue gas CO unstable.

[0005] Therefore, it is necessary to design a full-process CO2 collaborative governance process system and control method to solve the above-mentioned technical problems. Summary of the invention

[0006] Based on this, a full-process CO collaborative governance process system and control method are provided, which can intelligently regulate the CO concentration at the source, process and end of the whole process, ensure the efficient and stable operation of the system, and achieve stable and standard emission of CO concentration in the outlet flue gas.

[0007] In order to solve the above problems, the present application provides a full-process CO collaborative governance process system for treating the sintering flue gas discharged from a sintering machine, including: a front-end internal circulation system, a terminal purification system and a dynamic control system; each bellows of the sintering machine corresponds to a bellows flue connected to the exhaust flue gas, and the sintering flue gas in each bellows flue can choose to take the front-end internal circulation route of the front-end internal circulation system or the terminal purification route of the terminal purification system under the control of the dynamic control system; the front-end internal circulation system includes an internal circulation main flue, an internal circulation dust collector, a waste heat recovery system and a waste heat recovery device, and the sintering flue gas in each bellows flue is merged into one circulating flue gas through the internal circulation main flue, and enters the internal circulation dust collector and the waste heat recovery device in sequence. The flue gas is processed in the recovery device and returned to the sintering material surface of the sintering machine through the gas collecting hood to re-participate in the sintering process; the terminal purification system includes an external exhaust gas main flue, an external exhaust gas dust collector, a desulfurization reaction device and a NOx-CO reaction device; the sintering flue gas of each wind box flue is merged into one external exhaust gas through the external exhaust gas main flue, and enters the external exhaust gas dust collector, the desulfurization reaction device and the NOx-CO reaction device in turn for treatment, and the treated external exhaust gas enters the external exhaust chimney and is discharged; the dynamic control system can predict the CO concentration change of each wind box according to the sintering terminal data of the sintering machine, and dynamically adjust the amount of internal circulating flue gas in each wind box flue, so that the CO concentration of the flue gas entering the terminal purification system remains stable.

[0008] Preferably, the waste heat recovery device is communicatively connected to the dynamic control system; the dynamic control system can adjust the flue gas temperature at the outlet of the waste heat recovery device according to the flue gas flow rate and CO concentration of the circulating flue gas.

[0009] Preferably, the terminal purification system also includes a GGH heat exchanger; the GGH heat exchanger is arranged before the NOx-CO reaction device, and is used to recover the heat released by the exhaust gas after being treated by the NOx-CO reaction device, so as to reduce the gas consumption of the heater; the heater is arranged between the GGH heat exchanger and the NOx-CO reaction device, and is used to heat the exhaust gas.

[0010] Preferably, the NOx-CO reaction device comprises a reactor body; the upper layer of the reactor body is filled with a denitration catalyst; and the lower layer of the reactor body is filled with a de-CO catalyst.

[0011] Preferably, the CO removal catalyst is a non-precious metal catalyst; the non-precious metal catalyst uses a non-precious metal element of a transition metal as an active component, a rare earth metal as a co-catalyst and an oxygen storage material, and TiO2 and glass fiber as a carrier and a skeleton, wherein the active component is dispersed on the surface of the TiO2 carrier material in the form of nano-metal particles.

[0012] Preferably, the bellows flue is provided with a first electric actuator valve and a second electric actuator valve, and the first electric actuator valve and the second electric actuator valve are both communicatively connected to the dynamic control system; the first electric actuator valve is used to control the connection between the bellows flue and the internal circulation main flue, so as to realize the sintering flue gas taking the front-end internal circulation route of the front-end internal circulation system; the second electric actuator valve is used to control the connection between the bellows flue and the external exhaust flue gas main flue, so as to realize the sintering flue gas taking the terminal purification route of the terminal purification system.

[0013] Preferably, an internal circulation online detection instrument is also provided on the bellows flue, and the internal circulation online detection instrument is arranged after the first electric actuator valve and is communicatively connected to the dynamic control system; the dynamic control system can dynamically adjust the valve opening of the first electric actuator valve according to the real-time detection of the CO concentration entering the front-end internal circulation system by the internal circulation online detection instrument.

[0014] The present application also provides a control method for the full-process CO2 collaborative treatment process system, and the control method comprises the following steps:

[0015] Detect the CO concentration entering the wind box flue from the sintering machine wind box;

[0016] Determine whether the CO concentration in each of the wind box flues exceeds a preset threshold;

[0017] If the CO concentration in any of the bellows flue exceeds a preset threshold, the sintering flue gas in the bellows flue of that route is controlled to go through the front-end internal circulation system, and the sintering flue gas in the remaining other bellows flues is controlled to go through the terminal purification system; wherein, the total internal circulation flue gas flow rate of the front-end internal circulation system is set to be 25-30% lower than the initial threshold value. If it is 25-30% higher than the initial threshold value, part of the flue gas with relatively low CO concentration in the bellows flue is controlled to enter the terminal purification system.

[0018] Preferably, the method further includes the following steps: if the CO concentration in any of the wind box flues exceeds a preset threshold, the sintering flue gas in the wind box flue is controlled to go to the front end internal circulation system, and the sintering flue gas in the remaining wind box flues goes to the terminal purification system, including:

[0019] If the CO concentration in any of the bellows flue exceeds a preset threshold, the opening of the first electric actuator valve in the bellows flue is controlled to gradually increase and the opening of the second electric actuator valve is controlled to gradually decrease until the total flue gas flow in the internal circulation reaches the initial threshold of 25-30% or the CO concentration of the flue gas entering the terminal purification system reaches the initial concentration.

[0020] Preferably, the method further includes the following steps: using an internal circulation online detection instrument to detect the CO concentration entering the front-end internal circulation system online; and a dynamic control system predicts the CO concentration entering the front-end internal circulation system based on the terminal data of the sintering machine, and controls the valve opening of the first electric actuator valve (121) in the wind box flue of the road.

[0021] This application has at least the following beneficial effects:

[0022] The dynamic control system can monitor the CO concentration changes of each bellows in real time according to the sintering conditions such as the batching and the thickness of the material layer. Under the premise of not affecting the product and quality of the sintered ore, the flue gas from the bellows with higher CO concentration is sent to the front-end internal circulation system, and after being treated by the internal circulation dust collector and the waste heat recovery device of the front-end internal circulation system, it is evenly guided through the gas collecting hood and sent back to the sintering machine material surface to re-participate in the sintering process; the flue gas from the bellows with lower CO concentration is sent to the terminal purification system, and is treated in turn by the external exhaust gas dust collector, desulfurization reaction device and NOx-CO reaction device of the terminal purification system, and the treated external exhaust gas enters the external exhaust chimney and is discharged; the dynamic control system regulates the CO concentration changes at the source, process and end, and can adapt to operation under any working conditions, effectively solve the problems of low efficiency, instability and high cost of terminal treatment of the circulating flue gas system, ensure the efficient and stable operation of the system, achieve stable and standard emission of CO concentration of the outlet flue gas, and leave room for transformation for the future upgraded emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a full-process CO2 collaborative treatment process system in this embodiment.

[0024] Figure numerals: 10, sintering machine; 11, bellows; 12, bellows flue; 121, first electric actuator valve; 122, second electric actuator valve; 123, internal circulation online detection instrument; 20, front-end internal circulation system; 21, internal circulation main flue; 22, internal circulation dust collector; 23, waste heat recovery device; 24, gas collecting hood; 25, internal circulation fan; 30, terminal purification system; 31, external exhaust flue gas main flue; 32, external exhaust flue gas dust collector; 33, desulfurization reaction device; 34, NOx-CO reaction device; 35, GGH heat exchanger; 36, heater; 37, external exhaust fan; 38, exhaust fan; 40, dynamic control system; 50, external exhaust chimney. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0027] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0028] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0029] The embodiment of the present application provides a full-process CO collaborative governance process system and control method. Through the two-stage decarbonization collaborative governance of the dynamic management and control system and the front-end internal circulation system and the terminal purification system, the whole process can be intelligently controlled to adapt to the changes in sintering load and CO changes in the flue gas, ensuring efficient and stable operation of the system, achieving stable and standard emission of CO concentration in the outlet flue gas, and leaving room for modification for future upgraded emission standards.

[0030] The following is a detailed description of a full-process CO2 collaborative treatment process system provided by this embodiment in conjunction with the accompanying drawings. Please refer to Figure 1As shown, the process system is used to process the sintering flue gas discharged from the sintering machine 10, and mainly includes a front-end internal circulation system 20, a terminal purification system 30 and a dynamic control system 40; wherein, each bellows 11 of the sintering machine 10 corresponds to a bellows flue 12 connected to the exhaust flue gas, and the sintering flue gas in each bellows flue 12 can choose to take the front-end internal circulation route of the front-end internal circulation system 20 or the terminal purification route of the terminal purification system 30 under the control of the dynamic control system 40; the front-end internal circulation system 20 includes an internal circulation main flue 21, an internal circulation dust collector 22 and a waste heat recovery device 23, and the sintering flue gas in each bellows flue 12 is merged into a circulating flue gas through the internal circulation main flue 21, and enters the internal circulation dust collector 22 and the waste heat recovery device 23 for treatment through the action of the internal circulation fan 25, and the circulating flue gas is After being discharged from the waste heat recovery device 23, it is evenly guided through the gas collecting hood 24 and then sent back to the sintering material surface of the sintering machine 10 to re-participate in the sintering process; the terminal purification system 30 includes an external exhaust flue gas main flue 31, an external exhaust flue gas dust collector 32, a desulfurization reaction device 33 and a NOx-CO reaction device 34; the sintering flue gas of each wind box flue 12 is merged into one external exhaust flue gas through the external exhaust flue gas main flue 31, and enters the external exhaust flue gas dust collector 32, the desulfurization reaction device 33 and the NOx-CO reaction device 34 in turn for treatment, and the treated external exhaust flue gas enters the external exhaust chimney 50 and is discharged; the dynamic control system 40 can predict the CO concentration change of each wind box 11 according to the terminal data of the sintering machine 10, and dynamically adjust the amount of internal circulating flue gas in each wind box flue 12, so that the CO concentration of the flue gas entering the terminal purification system 30 remains stable.

[0031] In view of the problems in the prior art of low efficiency of the flue gas circulation system, poor adaptability to working conditions, and easy impact on the output and quality of sintered ore, a full-process CO collaborative treatment process system is provided in this embodiment. The process system uses a dynamic control system 40 to perform two-stage decarbonization collaborative treatment with a front-end internal circulation system 20 and a terminal purification system 30, and can intelligently control the CO concentration at the source, process and terminal of the whole process to ensure efficient and stable operation of the system and achieve stable and standard emission of the outlet flue gas CO concentration. While meeting the CO emission requirements through dynamic control, the CO in the sintering process can be achieved. 2Emissions are reduced by 25kg / ton of steel, CO and NOx emissions are significantly reduced, and ammonia escape and ammonium salt emissions are reduced. Specifically, the dynamic control system 40 monitors the CO concentration changes of each bellows 11 in real time according to the sintering conditions such as the ingredients and material layer thickness of the sintering machine 10. Under the premise of not affecting the product and quality of the sintered ore, the sintering flue gas with a higher CO concentration in the bellows flue 12 is controlled to go through the front-end internal circulation system 20, and after being treated by the internal circulation dust collector 22 and the waste heat recovery device 23, it re-enters the sintering material surface of the sintering machine 10 to participate in the sintering process; the sintering flue gas with a lower CO concentration in the bellows flue 12 is controlled to go through the terminal purification system 30, and this part of the sintering flue gas is successively discharged to the external flue gas dust collector 32, the desulfurization reaction device 23, and the desulfurization reaction device 23. 33 and the NOx-CO reaction device 34 are used for treatment. The treated exhaust gas is discharged through the exhaust chimney 50 after meeting the standards. Therefore, the dynamic control system 40 can predict the change of CO concentration according to the terminal data of the sintering machine 10, and dynamically adjust the amount of internal circulating flue gas in each bellows flue 12, that is, the sintering flue gas flow opening is achieved by controlling the valve opening, so that the CO concentration of the flue gas entering the terminal purification system 30 is maintained stable. In other words, according to the change of sintering load, the CO emission in the sintering process is reduced, the initial concentration of CO in the terminal catalytic oxidation is reduced, the difficulty of terminal transformation is reduced, and the coordinated control and stable emission of CO are achieved economically and efficiently.

[0032] In this embodiment, it should be noted that the dynamic management and control system 40 collects a large amount of data from the equipment terminal of the sintering machine 10, transmits the acquired data to the data model, and continuously makes dynamic adjustments based on self-learning of the data. The data model transmits the obtained results to the dynamic management and control system 40, which performs diagnosis, prediction, and decision-making, and transmits instructions to the sintering equipment. Specifically, the combustion condition of each material layer is calculated through thermodynamic simulation based on the data collected by the terminal equipment of the sintering machine 10, such as the material layer, material thickness, and temperature, and the permeability curve of each bellows 11 is predicted based on the combustion condition. The permeability curve mainly expresses the relationship between the flue gas flow rate Q and the material layer ΔP. The material layer ΔP is related to the combustion degree of the material layer. If the material layer burns more permeably during combustion, it indicates good permeability. At this time, the ΔP between the upper and lower layers of the material layer is small, which also indicates that the combustion is sufficient and the CO concentration is low. Then, the flue gas flow rate Q in the bellows 11 can be controlled according to the permeability curve. Therefore, the flue gas flow rate Q of each bellows 11 is allocated according to the permeability curve. For example, if the CO concentration in the bellows 11 is high, the flue gas of the bellows 11 is controlled to circulate internally, and the valve opening in the bellows flue 12 connected to the bellows 11 is controlled to gradually increase, thereby increasing the flue gas flow rate of the internal circulation.

[0033] The permeability curve is mainly obtained by constructing a nonlinear relationship between raw material properties, operating parameters, state parameters and permeability state, and performing a correlation analysis on the permeability of the material layer. The influence of various parameters of the current operating conditions on the permeability is analyzed, and then the permeability of the sintering process is obtained through the permeability formula. The permeability and flow rate at each position are obtained through the corresponding permeability formula of the bellows 11, and the permeability curves of the bellows 11 at different positions in the sintering process are obtained. Taking the permeability curves of the bellows 11 at different positions in the sintering process as a benchmark, during the sintering production process, the material layer ΔP in each bellows 11 is monitored, and the opening of each valve in the bellows flue 12 is adjusted to adjust the flue gas flow Q.

[0034] The air permeability formula is mainly as follows:

[0035]

[0036] Where: K gas - air permeability, ;

[0037] Q—smoke flow rate, ;

[0038] ΔP—pressure drop caused by gas passing through porous materials, KPa;

[0039] A—the area of ​​the sample test area,

[0040] In this embodiment, it should also be noted that the waste heat recovery device 23 is communicatively connected to the dynamic control system 40, and the dynamic control system 40 can adjust the flue gas temperature at the outlet of the waste heat recovery device 23 according to the flue gas flow rate and CO concentration of the circulating flue gas. After the circulating flue gas is dust-removed by the internal circulation dust collector 22, it enters the waste heat recovery device 23 for waste heat recovery to reduce the flue gas temperature of the circulating flue gas. The internal circulation fan 25 is arranged after the waste heat recovery device 23. Through the use of the waste heat recovery device 23, the flue gas temperature of the circulating flue gas can be controlled to be lowered, and the amount of working flue gas entering the sintering material surface can be reduced. While ensuring the output and quality of the sintered ore, the total amount of flue gas under the working conditions of the internal circulation flue gas is increased, thereby reducing the outlet concentration of CO. For example, the flue gas flow rate in the internal circulation total flue 21 is 200,000 Nm 3 / h, the flue gas temperature is 300℃, without considering the atmospheric pressure, the converted working condition is about 419700m 3 / h, the flue gas temperature decreases after passing through the waste heat recovery device 23. When the temperature drops to 200℃, the converted working condition is about 346500 m 3 / h, and the bellows duct 12 accommodates 500000m 3Therefore, the use of the waste heat recovery device 23 can control the temperature of the internally circulated flue gas, reduce the amount of working flue gas returned to the sintering material surface, and increase the total amount of internally circulated flue gas. Therefore, the general route of the front-end internal circulation system 20 is: sintering flue gas wind box 11 → dynamic control system 40 → internal circulation dust collector 22 → waste heat recovery device 23 → internal circulation fan 25 → air collection hood 24 returns to the material surface.

[0041] In one feasible manner, the waste heat recovery device 23 can be a gas-liquid contact type, and can specifically include a recovery tower, with an air outlet arranged at the top and an air inlet arranged at the bottom of the recovery tower. A spray pipe is also arranged in the recovery tower, and the spray pipe can be supplied with liquid from the outside. An electric valve is arranged on the spray pipe, and the electric valve is controlled by the dynamic control system 40, so that the electric valve is controlled to open by the dynamic control system 40, and the spray pipe sprays absorption liquid from top to bottom into the recovery tower, and the absorption liquid sprays the rising circulating flue gas, thereby absorbing the temperature of the circulating flue gas and playing a role in lowering the temperature of the circulating flue gas. The dynamic control system 40 can adjust the start and stop of the waste heat recovery device 23 according to the flue gas temperature of the circulating flue gas, that is, control the opening of the electric valve. If the flue gas temperature of the circulating flue gas is high, the dynamic control system 40 controls the electric valve of the waste heat recovery device 23 to open, and sprays spray liquid into the waste heat recovery device 23 to absorb the circulating flue gas; if the flue gas temperature is low, the dynamic control system 40 controls the electric valve of the waste heat recovery device 23 to stop, and the circulating flue gas does not recover waste heat at this time. Of course, the valve opening of the electric valve of the waste heat recovery device 23 can also be controlled to adjust the flow rate of the spray.

[0042] In this embodiment, it should be noted that the terminal purification system 30 also includes a GGH (Gas Gas The external exhaust fan 37 is arranged between the external exhaust gas dust collector 32 and the desulfurization reaction device 33, and is used to suck the sintering flue gas in the wind box 11 into the terminal purification system 30; the GGH heat exchanger 35 is arranged between the desulfurization reaction device 33 and the NOx-CO reaction device 34, that is, before the NOx-CO reaction device 34, and is used to recover the heat released by the external exhaust gas after being treated by the NOx-CO reaction device 34 to reduce the gas consumption of the heater 36; the heater 36 is arranged between the GGH heat exchanger 35 and the NOx-CO reaction device 34, and is used to heat the external exhaust gas. Preferably, the heater 36 can be a heating furnace; the smoke exhaust fan 38 is arranged between the GGH heat exchanger 35 and the external exhaust chimney 50, and is used to discharge the clean flue gas after being treated by the NOx-CO reaction device 34 and the GGH heat exchanger 35. The sintering flue gas discharged is desulfurized by the desulfurization reaction device 33 and then enters the NOx-CO reaction device 34, where NOx and CO are removed successively. The heat released is then utilized as waste heat through the GGH heat exchanger 35 to supplement the flue gas temperature at the denitrification inlet. Then, the clean flue gas enters the external exhaust chimney 50 for discharge under the action of the exhaust fan 38. Therefore, the general route of the terminal purification system 30 is sintering flue gas wind box 11 → dynamic control system 40 → external flue gas dust collector 32 → external exhaust fan 37 → desulfurization reaction device 33 → GGH heat exchanger 35 (original flue gas) → heater 36 → NOx reaction layer 341 → CO reaction layer 342 → GGH heat exchanger 35 (clean flue gas) → exhaust fan 38 → external exhaust chimney 50 → purified flue gas, thereby improving the heat recovery efficiency and saving gas. In the process of CO emission reduction, the sensible heat of flue gas and the latent heat of CO are fully utilized to increase the temperature of sintering flue gas, improve the waste heat recovery efficiency, increase the waste heat power generation, and the heat released by the terminal catalytic oxidation can replace the blast furnace gas used for denitrification and heating combustion, saving the consumption of blast furnace gas.

[0043] In some embodiments, the NOx-CO reaction device 34 includes a reactor body, the upper layer of the reactor body is a NOx reaction layer 341, filled with a denitration catalyst, the lower layer of the reactor body is a CO reaction layer 342, filled with a de-CO catalyst, and the reactor body is configured to have three layers, two of which are used to place the denitration catalyst, and the remaining layer is used as a spare layer. In this embodiment, a de-CO catalyst is placed in the spare layer. Preferably, the de-CO catalyst uses a non-precious metal catalyst, and the non-precious metal catalyst uses a non-precious metal element of a transition metal as an active component, a rare earth metal as a co-catalyst and an oxygen storage material, and TiO2 and glass fiber as a carrier and a skeleton, wherein the active component is dispersed on the surface of the TiO2 carrier material in the form of nano-metal particles to form a special material surface structure effect, and a special process is introduced to increase the material oxygen storage capacity and CO adsorption capacity.

[0044] In the present embodiment, it is also necessary to explain that a first electric actuator valve 121 and a second electric actuator valve 122 are provided on the bellows flue 12, and the first electric actuator valve 121 and the second electric actuator valve 122 are both communicatively connected to the dynamic control system 40; the first electric actuator valve 121 is used to control the connection between the bellows flue 12 and the internal circulation main flue 21, so as to realize the front-end internal circulation route of the sintering flue gas through the front-end internal circulation system 20; the second electric actuator valve 122 is used to control the connection between the bellows flue 12 and the external exhaust flue gas main flue 31, so as to realize the terminal purification route of the sintering flue gas through the terminal purification system 30. The dynamic control system 40 can monitor the CO concentration changes in each bellows flue 12 in real time according to the sintering conditions such as the batching and the thickness of the material layer, and control the valve opening on the bellows flue 12 at the same time. Under the premise of not affecting the product and quality of the sintered ore, the sintering flue gas in the bellows flue 12 with a higher CO concentration is internally circulated, and after being treated by the internal circulation dust collector 22, it is guided back to the sintering material surface through the gas collecting hood 24 under the action of the internal circulation fan 25; the sintering flue gas in the bellows flue 12 with a lower CO concentration is subjected to the terminal purification system 30, after passing through the external exhaust gas dust collector 32, it enters the desulfurization reaction device 33, GGH heat exchanger 35 (raw flue gas), heater 36, NOx reaction layer 341, CO reaction layer 342, GGH heat exchanger 35 (clean flue gas), exhaust fan 38, and external exhaust chimney 50 in sequence under the action of the external exhaust fan 37.

[0045] In some embodiments, an internal circulation online detection instrument 123 is also provided on the bellows flue 12. The internal circulation online detection instrument 123 is arranged after the first electric actuator valve 121 and is communicatively connected to the dynamic control system 40. The dynamic control system 40 can dynamically adjust the valve opening of the first electric actuator valve 121 according to the real-time detection of the CO concentration entering the front-end internal circulation system 20 by the internal circulation online detection instrument 123.

[0046] In this embodiment, a control method for the CO2 collaborative treatment process system according to the whole process is also provided, and the control method comprises the following steps:

[0047] Step 1: Detecting the CO concentration entering the wind box flue 12 from the wind box 11 of the sintering machine 10;

[0048] In this embodiment, a CO concentration detection instrument is used to detect the change in CO concentration entering the wind box flue 12 from the wind box 11 of the sintering machine 10 , and a signal of the CO concentration change is transmitted to the dynamic management and control system 40 .

[0049] Step 2: Determine whether the CO concentration in each bellows flue 12 exceeds a preset threshold; if the CO concentration in any bellows flue 12 exceeds the preset threshold, the sintering flue gas in the bellows flue 12 is controlled to go through the front-end internal circulation system 20, and the flue gas in the remaining other bellows flues 12 is controlled to go through the terminal purification system 30; wherein, the total internal circulation flue gas flow rate of the front-end internal circulation system 20 is set to be 25-30% lower than the initial threshold. If it is higher than the initial threshold of 25-30%, part of the flue gas with relatively low CO concentration in the bellows flue 12 is controlled to enter the terminal purification system 30.

[0050] In this embodiment, the dynamic management and control system 40 receives the CO concentration signal in each bellows flue 12 transmitted by the CO concentration detection instrument, and judges whether the CO concentration in each bellows flue 12 exceeds the preset threshold value. If the CO concentration in any bellows flue 12 exceeds the preset threshold value, the dynamic management and control system 40 controls the first electric actuator valve 121 in the bellows flue 12 to gradually increase the opening and the second electric actuator valve 122 to gradually decrease until the total internal circulation flue gas flow reaches the initial threshold value of 25-30%, or the CO concentration of the flue gas entering the terminal purification system 30 reaches the initial concentration.

[0051] The dynamic control system 40 controls the first electric actuator valve 121 in the remaining other wind box flues 12 to gradually decrease to close, and the second electric actuator valve 122 to gradually increase. Among them, the preset threshold, the initial threshold and the initial concentration can be set according to the actual CO concentration requirements and are not fixed.

[0052] Step 3: Use the internal circulation online detection instrument 123 to online detect the CO concentration entering the front-end internal circulation system 20; the dynamic management and control system 40 controls the valve opening of the first electric actuator valve 121 in the wind box flue 12 according to the terminal data prediction of the sintering machine 10 and the CO concentration entering the front-end internal circulation system 20.

[0053] In this embodiment, the dynamic control system 40 in this embodiment can also control the valve opening of the first electric actuator valve 121 and the second electric actuator valve 122 .

[0054] Specifically, the CO concentration entering the front-end internal circulation system 20 is detected online by using the internal circulation online detection instrument 123, and the valve opening of the first electric actuator valve 121 in the bellows flue 12 is controlled according to the terminal data analysis and prediction of the dynamic management and control system 40 and the CO concentration entering the front-end internal circulation system 20. For example, in the sintering production process, by monitoring the material layer ΔP in each wind box 11, the combustion condition of the material layer can be understood according to the material layer ΔP, and then the opening of each valve (the first electric actuator valve 121 and the second electric actuator valve 122) in the wind box flue 12 can be adjusted according to the material layer ΔP to adjust the flue gas flow Q. For example, the smaller the material layer ΔP is, the more thorough the surface combustion is, and then the CO concentration will be lower. Then the opening of the first electric actuator valve 121 in the wind box flue 12 can be controlled to gradually decrease, and the opening of the second electric actuator valve 122 can be gradually increased, so that the low concentration of CO goes to the terminal purification system 30; the larger the material layer ΔP is, the lower the permeability of the surface combustion is, and then the CO concentration will be higher. Then the opening of the first electric actuator valve 121 in the wind box flue 12 can be controlled to gradually increase, and the opening of the second electric actuator valve 122 can be gradually reduced, so that the high concentration of CO goes to the front end internal circulation system 20.

[0055] The initial CO concentration entering the terminal purification system 30, i.e., the terminal NOx-CO reaction device 34, can also be detected online by using a terminal online detection instrument (not shown in the figure) arranged on the external exhaust gas main duct 31, and the valve opening of the second electric actuator valve 122 in each wind box duct 12 can be controlled according to the initial CO concentration entering the terminal purification system 30.

[0056] Principle of the embodiment of the present invention: In the existing process flow, the efficiency of removing CO from flue gas by source process treatment is low, the operating conditions fluctuate greatly, and the treatment effect is limited. The end-of-pipe treatment mostly uses precious metal catalysts, which are costly and short-lived. At the same time, the reactor needs to be modified, which increases the system resistance. In the embodiment of the present application, a two-stage decarbonization collaborative treatment is performed through a dynamic control system 40, a front-end internal circulation system 20, and a terminal purification system 30. The dynamic control system 40 collects data from the sintering terminal, accurately predicts the CO concentration change of each bellows, and dynamically adjusts the internal circulation flue gas volume of each bellows to ensure the stability of the CO concentration of the sintering exhaust gas, reduce the end-of-pipe treatment cost, and cooperates with non-precious metal catalytic oxidation technology for collaborative treatment to reduce the consumption of blast furnace gas. The existing end-of-pipe treatment technology has high cost and large transformation. At the same time, waste heat is recovered to save gas and ammonia consumption. The system can reduce the use of coke powder by 5%-10%, reduce production costs, and reduce the initial concentration of terminal CO treatment, so that the terminal catalytic oxidation collaborative treatment transformation is small and economical and efficient.

[0057] With a 265m 2 Taking sintering as an example, the sintering flue gas volume is 1.2 million Nm 3 / h, inlet CO concentration is about 9000 mg / Nm 3 The CO concentration in each wind box is 7000 mg / Nm 3 ~11000 mg / Nm 3 The dynamic control system 40 predicts the CO concentration change of each bellows flue gas according to the sintering conditions such as batching and material layer thickness, and fine-tunes the valve opening of each bellows based on the concentration feedback of the bellows online monitoring, so as to circulate the flue gas with high CO concentration internally and control the temperature of the internal circulating flue gas at the same time to ensure that the maximum circulating flue gas volume does not exceed 400,000 Nm 3 / h. Through source and process control, the flue gas CO concentration entering the terminal treatment system is stabilized at 4500mg / Nm 3 ~5000 mg / Nm 3 Under the coordinated treatment of terminal catalytic oxidation technology, the outlet flue gas CO concentration is 2500 mg / Nm 3 About two-thirds of blast furnace gas consumption can be saved.

[0058] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A full-process CO synergistic treatment process system for treating sintering flue gas discharged from a sintering machine (10), characterized in that: include: A front-end internal circulation system (20), a terminal purification system (30) and a dynamic control system (40); Each wind box (11) of the sintering machine (10) is respectively connected to a wind box flue (12) for exhausting flue gas, and the sintering flue gas in each wind box flue (12) can choose to follow the front-end internal circulation route of the front-end internal circulation system (20) or the terminal purification route of the terminal purification system (30) under the control of the dynamic control system (40); The front-end internal circulation system (20) comprises an internal circulation main flue (21), an internal circulation dust collector (22) and a waste heat recovery device (23); the sintering flue gas of each wind box flue (12) is merged into a circulating flue gas through the internal circulation main flue (21), and enters the internal circulation dust collector (22) and the waste heat recovery device (23) in sequence for treatment, and returns to the sintering material surface of the sintering machine (10) through the gas collecting hood (24) to participate in the sintering process again; the waste heat recovery device (23) is communicatively connected to the dynamic control system (40); the dynamic control system (40) can adjust the flue gas temperature at the outlet of the waste heat recovery device (23) according to the flue gas flow rate and CO concentration of the circulating flue gas; The terminal purification system (30) comprises an external exhaust gas main flue (31), an external exhaust gas dust collector (32), a desulfurization reaction device (33) and a NOx-CO reaction device (34); the sintering flue gas of each wind box flue (12) is combined into one external exhaust flue gas through the external exhaust gas main flue (31), and enters the external exhaust gas dust collector (32), the desulfurization reaction device (33) and the NOx-CO reaction device (34) in sequence for treatment, and the treated external exhaust gas enters the external exhaust chimney (50) and is discharged; The dynamic control system (40) can predict the CO concentration change of each wind box (11) according to the terminal data of the sintering machine (10), and dynamically adjust the internal circulation flue gas volume in each wind box flue (12), so that the CO concentration of the flue gas entering the terminal purification system (30) remains stable; The bellows flue (12) is provided with a first electric actuator valve (121) and a second electric actuator valve (122), and the first electric actuator valve (121) and the second electric actuator valve (122) are both communicatively connected to the dynamic control system (40); the first electric actuator valve (121) is used to control the connection between the bellows flue (12) and the internal circulation main flue (21), so as to realize the front-end internal circulation route of the sintering flue gas through the front-end internal circulation system (20); the second electric actuator valve (122) is used to control the connection between the bellows flue (12) and the external exhaust flue gas main flue (31), so as to realize the terminal purification route of the terminal purification system (30); The dynamic control system (40) controls the valve opening of the first electric actuator valve (121) in the wind box flue (12) according to the terminal data prediction of the sintering machine (10) and the CO concentration entering the front-end internal circulation system (20); if the CO concentration in any of the wind box flue (12) exceeds a preset threshold, the opening of the first electric actuator valve (121) in the wind box flue (12) is controlled to gradually increase, and the opening of the second electric actuator valve (122) is controlled to gradually decrease, until the total internal circulation flue gas flow reaches an initial threshold of 25-30% or the CO concentration of the flue gas entering the terminal purification system (30) reaches the initial concentration.

2. The full-process CO2 collaborative treatment process system according to claim 1 is characterized in that: The terminal purification system (30) further includes a GGH heat exchanger (35) and a heater (36); The GGH heat exchanger (35) is arranged before the NOx-CO reaction device (34) and is used to recover the heat released by the exhaust gas after being treated by the NOx-CO reaction device (34) so ​​as to reduce the gas consumption of the heater (36); The heater (36) is arranged between the GGH heat exchanger (35) and the NOx-CO reaction device (34) and is used to heat the exhaust gas.

3. The full-process CO2 collaborative treatment process system according to claim 2 is characterized in that: The NOx-CO reaction device (34) comprises a reactor body; The upper layer of the reactor body is filled with a denitration catalyst; The lower layer of the reactor body is filled with a CO removal catalyst.

4. The full-process CO2 collaborative treatment process system according to claim 3 is characterized in that: The CO removal catalyst is a non-precious metal catalyst; The non-precious metal catalyst uses non-precious metal elements of transition metals as active components, rare earth metals as co-catalysts and oxygen storage materials, and TiO2 and glass fiber as carriers and skeletons, wherein the active components are dispersed on the surface of the TiO2 carrier material in the form of nano-metal particles.

5. The full-process CO2 collaborative treatment process system according to claim 1 is characterized in that: The wind box flue (12) is also provided with an internal circulation online detection instrument (123), the internal circulation online detection instrument (123) is arranged after the first electric actuator valve (121), and is communicatively connected to the dynamic control system (40); The dynamic control system (40) can dynamically adjust the valve opening of the first electric actuator valve (121) according to the concentration of CO entering the front-end internal circulation system (20) detected in real time by the internal circulation online detection instrument (123).

6. A control method for a full-process CO2 collaborative treatment process system according to any one of claims 1 to 5, characterized in that: The control method comprises the following steps: detecting the concentration of CO entering a wind box flue (12) from a wind box (11) of a sintering machine (10); Determining whether the CO concentration in each of the wind box flues (12) exceeds a preset threshold; If the CO concentration in any of the wind box flues (12) exceeds a preset threshold, the sintering flue gas in the wind box flue (12) is controlled to flow through the front-end internal circulation system (20), and the sintering flue gas in the remaining wind box flues (12) is controlled to flow through the terminal purification system (30); The total internal circulation flue gas flow rate of the front-end internal circulation system (20) is set to be 25-30% lower than the initial threshold value. If it is 25-30% higher than the initial threshold value, part of the flue gas with relatively low CO concentration in the wind box flue (12) is controlled to enter the terminal purification system (30).

7. The control method according to claim 6, characterized in that: The following steps are also included: The concentration of CO entering the front-end internal circulation system (20) is detected online using an internal circulation online detection instrument (123).

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