CN111412755A - Method for reducing emission concentration of nitric oxide in steel rolling heating furnace - Google Patents
Method for reducing emission concentration of nitric oxide in steel rolling heating furnace Download PDFInfo
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- CN111412755A CN111412755A CN202010140611.1A CN202010140611A CN111412755A CN 111412755 A CN111412755 A CN 111412755A CN 202010140611 A CN202010140611 A CN 202010140611A CN 111412755 A CN111412755 A CN 111412755A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/46—Details, e.g. noise reduction means
- F23D14/48—Nozzles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D13/00—Apparatus for preheating charges; Arrangements for preheating charges
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/004—Systems for reclaiming waste heat
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Abstract
The invention discloses a method for reducing the nitrogen oxide emission concentration of a steel rolling heating furnace, which is applied to a heating value of 1000Kcal/Nm3‑2500Kcal/Nm3The control of the high, coke, rotary mixed gas heating furnace of (1), the heating furnace includes: the method comprises a preheating section, a first heating section, a second heating section and a soaking section which are sequentially communicated and the temperature of a hearth is increased, and comprises the following steps: controlling a first excess air coefficient of the preheating section to be 1.1-1.5, a second excess air coefficient of the first heating section to be 0.8-1.1, and a third excess air coefficient of the second heating section and the soaking end to be 0.7-1.0, wherein the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are sequentially decreased in a descending manner. The preheating section, the first heating section, the second heating section and the soaking are reasonably optimizedThe surplus air coefficient of section prevents that oxygen and nitrogen gas that are rich in the combustion process from generating nitrogen oxide under high temperature, under the prerequisite that does not influence the burning, the make full use of the energy, realizes reducing nitrogen oxide concentration's in the flue gas purpose.
Description
Technical Field
The invention relates to the technical field of heating furnace flue gas emission, in particular to a method for reducing the emission concentration of nitric oxide in a steel rolling heating furnace.
Background
Nitrogen oxides (NOx) which are one of the main pollutants causing atmospheric pollution and whose main components include NO, N2O, NO3, N2O3, N2O4, N2O5 and the like, are evolved in the atmosphere to form nitric acid and particulate matter containing nitrate, which is one of the main pollutants forming acid rain.
Nitrogen oxides in flue gas of a heating furnace are heavy pollution sources of a hot rolling plant, and at present, three main technical approaches for reducing nitrogen emission of the heating furnace are provided, namely: eliminating nitrogen oxide through chemical reaction in denitration facility; secondly, the low-nitrogen oxide combustor is utilized to reduce the generation of nitrogen oxide by improving the mixed combustion condition of air and fuel gas; and thirdly, an oxygen enrichment technology is adopted to reduce the proportion of nitrogen in the combustion-supporting gas. In the implementation of these techniques, if the heating process parameters are not properly controlled, the amount of nitrogen oxide emissions will also increase. The hourly mean concentration of nitrogen oxide emission of most of steel rolling heating furnaces of steel mills is controlled to be 150mg/m3The above.
Disclosure of Invention
The embodiment of the application provides a method for reducing the nitrogen oxide emission concentration of a steel rolling heating furnace, and the heating furnace is kept in an optimal state by optimizing parameters of a heating process on the premise of not modifying the existing equipment, so that the technical problem of high nitrogen oxide concentration in the smoke emitted by the steel rolling heating furnace in the prior art is solved.
The application provides the following technical scheme through an embodiment of the application:
a method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace is applied to a heating value of 1000Kcal/Nm3-2500Kcal/Nm3The control of the high, coke, rotary mixed gas heating furnace of (1), the heating furnace includes: the method comprises a preheating section, a first heating section, a second heating section and a soaking section which are sequentially communicated and the temperature of a hearth is increased, and comprises the following steps: controlling a first excess air coefficient of the preheating section to be 1.1-1.5, a second excess air coefficient of the first heating section to be 0.8-1.1, and a third excess air coefficient of the second heating section and the soaking end to be 0.7-1.0, wherein the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are sequentially decreased in a descending manner.
In one embodiment, the method further comprises: controlling the temperature of a first hearth of the preheating section not to exceed 1180 ℃; controlling the temperature of a second hearth of the first heating section not to exceed 1220 ℃; controlling the temperature of a third hearth of the second heating section not to exceed 1260 ℃; controlling the temperature of a fourth hearth of the soaking section not to exceed 1280 ℃; and the first hearth temperature, the second hearth temperature, the third hearth temperature and the fourth hearth temperature are sequentially increased in an increasing manner.
In one embodiment, the method further comprises: controlling the temperature rising speed of the slab in the soaking section to be more than 0.9 ℃/min.
In one embodiment, the method further comprises: and controlling the temperature rising speed of the hearth of the second heating section furnace and the soaking section not to exceed 12 ℃/min.
In one embodiment, the method further comprises: the opening degree of an air valve of the first pair of burners of the soaking section close to the outlet furnace door is controlled to be 40-60%, and the opening degree of a gas valve of the first pair of burners of the soaking section close to the outlet furnace door is controlled to be 90-100%.
In one embodiment, the method further comprises: when the thermal load is reduced and the burner needs to be closed, controlling the first closing time of an air valve of the burner to be earlier than the second closing time of a gas valve of the burner; when the thermal load is increased and the burner needs to be opened, controlling the first opening time of a gas valve of the burner to be earlier than the second opening time of an air valve of the burner, wherein the thermal load is the heat required by the slab.
In one embodiment, the method further comprises: the interval time between the first closing time and the second closing time is not more than 5 s; the interval time between the first opening time and the second opening time is not more than 5 s.
In one embodiment, the method further comprises: and controlling the hearth pressure of the preheating section, the first heating section, the second heating section and the soaking section to be 15-40 Pa.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
since the amount of nitrogen oxide produced is related to the temperature (the higher the temperature is, the more the amount of nitrogen oxide produced is, and the lower the temperature is, the less the amount of nitrogen oxide produced is), the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are controlled to be successively decreased in accordance with the principle that the temperature is gradually decreased from low to high (that is, the supplied air is gradually decreased) in consideration of the fact that the temperatures of the furnace chambers of the preheating section, the first heating section, the second heating section and the soaking section are successively increased, and the excess air coefficient set in the high temperature zone is ensured to be higher than the excess air coefficient set in the low temperature zone, so that the amount of air involved in the reaction is relatively decreased to relatively suppress the promotion effect of the high temperature on the amount of nitrogen oxide produced, thereby reducing the amount of nitrogen oxide produced. In addition, the third excess air coefficient of the high-temperature area (a second heating section and a soaking section for stably heating the plate blank) is ensured to be lower than 1, so that the smoke generated in the high-temperature area is in an oxygen-deficient environment, and nitrogen oxides generated by the reaction of nitrogen and oxygen in the smoke in the high-temperature area can be eliminated; meanwhile, the first excess air coefficient of a low-temperature area (a preheating section for preheating a plate blank) is higher than 1, namely, the air quantity is relatively surplus, so that the smoke generated by the high-temperature area can react with the smoke generated by the high-temperature area by using the surplus air quantity when flowing to the low-temperature area, the smoke generated by incomplete combustion in the high-temperature area is utilized in the section, and no waste is caused.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a schematic structural view of a steel rolling heating furnace provided in an embodiment of the present application.
FIG. 2 is a flow chart of a method for reducing the concentration of nitrogen oxide emissions from a steel rolling heating furnace according to an embodiment of the present application.
Detailed Description
The embodiment of the application provides a method for reducing the nitrogen oxide emission concentration of a steel rolling heating furnace, and the heating furnace is kept in an optimal state by optimizing parameters of a heating process on the premise of not modifying the existing equipment, so that the technical problem of high nitrogen oxide concentration in the smoke emitted by the steel rolling heating furnace in the prior art is solved.
In order to solve the technical problems, the method for reducing the emission concentration of nitrogen oxides of the steel rolling heating furnace is applied to the heating value of 1000Kcal/Nm3-2500Kcal/Nm3The control of the high, coke, rotary mixed gas heating furnace of (1), the heating furnace includes: a preheating section, a first heating section, a second heating section and a soaking section which are sequentially communicated and the temperature of the hearth is increased progressively.
The structure of the high coke-turning mixed gas heating furnace is shown in figure 1, and the high coke-turning mixed gas heating furnace sequentially comprises the following components along the running direction of a slab: a heat recovery section 1, a preheating section 2, a first heating section 3, a second heating section 4 and a soaking section 5. The heat recovery section 1 is provided with an inlet furnace door 12 and a smoke discharge port 11, the inlet furnace door 12 is used for allowing the plate blank to enter the furnace, the smoke discharge port 11 is used for discharging smoke in the furnace, and a fan is arranged at the position of the smoke discharge port 11 and used for providing power to draw out the smoke in the furnace, so that the movement direction of the smoke of each heating section in the furnace is opposite to the movement direction of the plate blank. The preheating section 2, the first heating section 3, the second heating section 4 and the soaking section 5 are provided with a plurality of pairs of burners at intervals, two burners of the pair of burners are respectively arranged at two sides of the furnace body, one burner is provided with an air valve and a gas valve, the system supplies high, coke and mixed gas and air to each heating section through the burners, and controls the amount of the mixed gas and the air by controlling the air valve and the gas valve on the burners. The end of the soaking section 5 far away from the second heating section 4, namely the tail end of the heating furnace, is provided with an outlet furnace door 52 for discharging the slabs.
As shown in fig. 1 and 2, the method includes:
controlling a first excess air coefficient of the preheating section 2 to be 1.1-1.5, a second excess air coefficient of the first heating section 3 to be 0.8-1.1, and a third excess air coefficient of the second heating section 4 and the heat equalizing end to be 0.7-1.0, wherein the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are sequentially decreased in a descending manner.
It should be noted that there are three pathways for nitrogen oxide formation: 1) the nitrogen and the oxygen are generated by reaction in the combustion process; 2) reacting nitrogen in the flue gas generated by combustion with oxygen; 3) the combustion of the nitrides in the fuel; 4) the hydrocarbons in the fuel are formed by co-reaction with nitrogen and oxygen. Wherein the control of the excess air ratio of the present application primarily controls the amount of the second type of nitrogen oxides produced.
The main way of generating nitrogen oxides is that nitrogen and oxygen react at high temperature to generate NO and NO2, when the excess air coefficient is larger than 1, the air supply exceeds the consumption, except nitrogen oxides formed in the combustion process, free oxygen exists in flue gas after combustion, the free oxygen can further react with nitrogen at high temperature to form nitrogen oxides, and the excess air coefficient of a high-temperature area is strictly controlled, so that the generation of the nitrogen oxides can be reduced. Therefore, the excess air coefficient of the high-temperature area is reduced, the smoke of the high-temperature area is in a poor oxygen environment, nitrogen oxides generated by the reaction of nitrogen and oxygen in the smoke can be eliminated, but the excess air coefficient of the high-temperature area cannot be too low, so that coal gas can be incompletely combusted, and energy is wasted; when the flue gas flows to the low-temperature region, the reaction speed of the nitrogen and the oxygen is reduced or the nitrogen and the oxygen hardly react, excessive oxygen exists in time, and the generation amount of nitrogen oxides is not obviously influenced, so that the air quantity can be properly increased, namely, the first excess air coefficient is controlled to be more than 1, and the incompletely combusted fuel can be utilized. The invention creatively sets the gradient excess air coefficient control standard according to different temperatures of each section in the heating furnace, can effectively reduce the generation amount of nitrogen oxides in flue gas, and simultaneously ensures the full utilization of energy.
Specifically, the first excess air coefficient may be 1.1, 1.2, 1.3, 1.4, 1.5, the second excess air coefficient may be 0.8, 0.9, 1.0, 1.1, and the third excess air coefficient may be 0.7, 0.8, 0.9, 1.0, and the residual oxygen value at the furnace end may be ensured to be not more than 5% by controlling the excess air coefficients of the respective heating stages.
As an alternative embodiment, the method further comprises:
controlling the temperature of a first hearth of the preheating section 2 not to exceed 1180 ℃; controlling the temperature of a second hearth of the first heating section 3 not to exceed 1220 ℃; controlling the temperature of a third hearth of the second heating section 4 not to exceed 1260 ℃; controlling the temperature of a fourth hearth of the soaking section 5 not to exceed 1280 ℃;
and the first hearth temperature, the second hearth temperature, the third hearth temperature and the fourth hearth temperature are sequentially increased in an increasing manner.
The lower limits of the first furnace temperature, the second furnace temperature, the third furnace temperature, and the fourth furnace temperature are set according to the amount of heat required for the slab, and are not limited here. In this embodiment, the upper limits of the first furnace temperature, the second furnace temperature, the third furnace temperature and the fourth furnace temperature are controlled, the upper limit temperature of each heating section is strictly controlled, and compared with the prior art, the maximum temperature of each furnace is reduced, and the generation rate of nitrogen oxides is limited.
As an alternative embodiment, the method further comprises:
the temperature rising speed of the slab in the soaking section 5 is controlled to be more than 0.9 ℃/min.
It should be noted that the slab heating rate is high, the required air flow rate and gas flow rate increase, and when the flow rate is high, the air or gas valve detection accuracy improves with respect to when the flow rate is low.
Specifically, the temperature rise of the slab is promoted by the temperature of the hearth, and when the temperature rise speed of the slab is more than 0.9, the temperature of the hearth needs to be increased to realize the temperature rise.
As an alternative embodiment, the method further comprises:
and controlling the temperature rising speed of the hearth of the second heating section 4 furnace and the soaking section 5 not to exceed 12 ℃/min.
In addition, the temperature of the furnace must be raised slowly in advance to maintain the temperature rise rate of the slab at 0.9 ℃/min or more, and the temperature of the furnace cannot be raised rapidly in a short time.
As an alternative embodiment, the method further comprises:
the opening degree of an air valve of the first pair of burners 51 of the soaking section 5 close to the outlet furnace door 52 is controlled to be 40-60%, and the opening degree of a gas valve of the first pair of burners 51 of the soaking section 5 close to the outlet furnace door 52 is controlled to be 90-100%.
Specifically, the air valve opening degree of the first pair of burners 51 may be 40%, 50%, or 60%, and the gas valve opening degree of the first pair of burners 51 may be 100%.
In practical application, since the outlet furnace door 52 needs to be opened at any time, a small amount of air will be sucked in the process, the embodiment can ensure that the position close to the outlet furnace door 52 is in a gas incomplete combustion state by reducing the opening degree of the air valves of the first pair of burners 51 close to the outlet furnace door 52, and even if a small amount of air is sucked, the oxygen in the air is consumed, so that the oxygen content in the soaking section 5 is controlled, and the generation amount of nitrogen oxides is reduced.
As an alternative embodiment, the method further comprises:
when the thermal load is reduced and the burner needs to be closed, controlling the first closing time of an air valve of the burner to be earlier than the second closing time of a gas valve of the burner;
when the thermal load is increased and the burner needs to be opened, controlling the first opening time of a gas valve of the burner to be earlier than the second opening time of an air valve of the burner, wherein the thermal load is the heat required by the slab.
This embodiment can prevent the air valve from opening first or closing later during the process of opening and closing the burner, resulting in additional air being supplied into the furnace.
As an alternative embodiment, the method further comprises:
the interval time between the first closing time and the second closing time is not more than 5 s;
the interval time between the first opening time and the second opening time is not more than 5 s.
As an alternative embodiment, the method further comprises:
and controlling the hearth pressure of the preheating section 2, the first heating section 3, the second heating section 4 and the soaking section 5 to be 15-40 Pa. Specifically, the furnace pressure may be 15Pa, 20Pa, 30Pa, 40 Pa.
It should be noted that the pressure of the hearth needs to be set at 15-40 Pa, and an excessively high pressure can cause fire to fire the outlet furnace door 52 and affect normal production; too low will cause cold air to be sucked from the outlet door 52, resulting in an increase in oxygen concentration and an increase in the production of nitrogen oxides.
After the invention is implemented, the average value of the emission hour discharge amount of nitrogen oxides is 130mg/m3Reduced to 90mg/m3The smoke emission of each heating furnace of 8 hot rolling furnaces is about 20 ten thousand cubic meters per hour, the heating furnaces are operated for 11 months per year, the emission of nitrogen oxides is reduced by 8X 200000X (130-90)/1000X 24X 30X 11-506.88 tons per year, and the temporary method of paid use and trade management of the emission right of Hebei province is adoptedThe price of nitrogen oxide per ton is 6000 yuan, and the economic benefit is 6000 x 506.88-304.1 ten thousand yuan/year. Simultaneously, the hour-average concentration of nitrogen oxides in the smoke of the steel rolling heating furnace is controlled to be 100mg/m3The emission standard of the ultra-low emission in Hebei province is 150mg/m3The method strongly supports the implementation of environmental protection policies in China.
The technical scheme in the embodiment of the application at least has the following technical effects or advantages:
since the amount of nitrogen oxide produced is related to the temperature (the higher the temperature is, the more the amount of nitrogen oxide produced is, and the lower the temperature is, the less the amount of nitrogen oxide produced is), the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are controlled to be successively decreased in accordance with the principle that the temperature is gradually decreased from low to high (that is, the supplied air is gradually decreased) in consideration of the fact that the temperatures of the furnace chambers of the preheating section 2, the first heating section 3, the second heating section 4 and the soaking section 5 are successively increased, and the excess air coefficient set in the high temperature zone is higher than the excess air coefficient set in the low temperature zone, so that the amount of air involved in the reaction is relatively decreased to relatively suppress the promotion effect of the high temperature on the amount of nitrogen oxide produced, thereby reducing the amount of nitrogen oxide produced. In addition, the third excess air coefficient of the high-temperature area (the second heating section 4 and the soaking section 5 for stably heating the plate blank) is ensured to be lower than 1, so that the smoke generated in the high-temperature area is in an oxygen-deficient environment, and nitrogen oxides generated by the reaction of nitrogen and oxygen in the smoke in the high-temperature area can be eliminated; meanwhile, the first excess air coefficient of a low-temperature area (a preheating section 2 for preheating the plate blank) is higher than 1, namely, the air quantity is relatively surplus, so that the smoke generated in the high-temperature area can react with the smoke generated in the high-temperature area by using the surplus air quantity when flowing to the low-temperature area, the smoke generated in the high-temperature area due to incomplete combustion is utilized in the section, and no waste is caused.
Example one
Using 2000Kcal/Nm3The high, coke and rotary mixed gas heats the plate blank in the heating furnace, the pressure of the hearth is controlled to be 25Pa, the opening degree of a first pair of burners 51 of the soaking section 5 close to the steel tapping furnace door is controlled to be 50 percent, and the opening degree of a gas hand valve is controlled to be 100 percent. Controlling the excess air coefficient of the soaking section 5 and the second heating section to be 0.7; controlling the excess air coefficient of the first heating section 3 to be 1.0; controlling the excess air coefficient of the preheating section 2 to be 1.2, analyzing and measuring the components of the furnace tail smoke through a smoke analyzer, wherein the residual oxygen value of the furnace tail is 3.5%, the hearth temperature of the soaking section 5 is 1255 ℃, the hearth temperature of the second heating section is 1230 ℃, the hearth temperature of the first heating section 3 is 1185 ℃, and the hearth temperature of the preheating section 2 is 1040 ℃. When the burner is closed, the air valve is closed first and then is closed; when the burner is opened, the gas valve needs to be opened first, and then the air valve needs to be opened, and the interval time is 4 seconds. The temperature rising speed of the slab in the soaking section 5 is controlled to be 1.2 ℃/min, and the temperature rising speed of the second heating section 4 furnace and the soaking section 5 chamber is controlled to be 9 ℃/min. The nitrogen oxide detection data are shown in table 1.
Table 1: mean concentration of nitrogen oxide emissions within 24 hours
Example two
Using 2100Kcal/Nm3The high, coke and rotary mixed gas heats the plate blank in the heating furnace, the pressure of the hearth is controlled to be 20Pa, the opening degree of a first pair of burners 51 of the soaking section 5 close to the steel tapping furnace door is controlled to be 50 percent of the air hand valve, the opening degree of the gas hand valve is controlled to be 100 percent, and the opening degrees of the rest burners are controlled to be 100 percent of the air hand valve and the gas hand valve. Controlling the excess air coefficient of the soaking section 5 and the second heating section to be 0.8; controlling the excess air coefficient of the first heating section 3 to be 0.9; the excess air coefficient of the preheating section 2 is controlled to be 1.1, the residual oxygen value at the tail of the furnace is 2%, the temperature of a hearth of the soaking section 5 is 1270 ℃, the temperature of a hearth of the second heating section is 1250 ℃, the temperature of a hearth of the first heating section 3 is 1205 ℃, and the temperature of a hearth of the preheating section 2 is 1100 ℃. When the burner is closed, the air valve is closed first and then is closed; when the burner is opened, the gas valve needs to be opened first and then openedAnd air valve interval of 2 seconds. The temperature rising speed of the slab in the soaking section 5 is controlled to be 1.6 ℃/min, and the temperature rising speed of the second heating section 4 furnace and the soaking section 5 chamber is controlled to be 11 ℃/min. The nitrogen oxide detection data are shown in table 2.
Table 2: mean concentration of nitrogen oxide emissions within 24 hours
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. A method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace is applied to a heating value of 1000Kcal/Nm3-2500Kcal/Nm3The control of the high, coke, rotary mixed gas heating furnace of (1), the heating furnace includes: the preheating section, the first heating section, the second heating section and the soaking section are sequentially communicated and the temperature of the hearth is increased, and the method is characterized by comprising the following steps of:
controlling a first excess air coefficient of the preheating section to be 1.1-1.5, a second excess air coefficient of the first heating section to be 0.8-1.1, and a third excess air coefficient of the second heating section and the soaking end to be 0.7-1.0, wherein the first excess air coefficient, the second excess air coefficient and the third excess air coefficient are sequentially decreased in a descending manner.
2. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
controlling the temperature of a first hearth of the preheating section not to exceed 1180 ℃; controlling the temperature of a second hearth of the first heating section not to exceed 1220 ℃; controlling the temperature of a third hearth of the second heating section not to exceed 1260 ℃; controlling the temperature of a fourth hearth of the soaking section not to exceed 1280 ℃;
and the first hearth temperature, the second hearth temperature, the third hearth temperature and the fourth hearth temperature are sequentially increased in an increasing manner.
3. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
controlling the temperature rising speed of the slab in the soaking section to be more than 0.9 ℃/min.
4. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
and controlling the temperature rising speed of the hearth of the second heating section furnace and the soaking section not to exceed 12 ℃/min.
5. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
the opening degree of an air valve of the first pair of burners of the soaking section close to the outlet furnace door is controlled to be 40-60%, and the opening degree of a gas valve of the first pair of burners of the soaking section close to the outlet furnace door is controlled to be 90-100%.
6. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
when the thermal load is reduced and the burner needs to be closed, controlling the first closing time of an air valve of the burner to be earlier than the second closing time of a gas valve of the burner;
when the thermal load is increased and the burner needs to be opened, controlling the first opening time of a gas valve of the burner to be earlier than the second opening time of an air valve of the burner, wherein the thermal load is the heat required by the slab.
7. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 6, further comprising:
the interval time between the first closing time and the second closing time is not more than 5 s;
the interval time between the first opening time and the second opening time is not more than 5 s.
8. The method for reducing nitrogen oxide emission concentration of a steel rolling heating furnace according to claim 1, further comprising:
and controlling the hearth pressure of the preheating section, the first heating section, the second heating section and the soaking section to be 15-40 Pa.
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| CN202010140611.1A CN111412755A (en) | 2020-03-03 | 2020-03-03 | Method for reducing emission concentration of nitric oxide in steel rolling heating furnace |
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| CN202010140611.1A CN111412755A (en) | 2020-03-03 | 2020-03-03 | Method for reducing emission concentration of nitric oxide in steel rolling heating furnace |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112146458A (en) * | 2020-09-09 | 2020-12-29 | 武汉钢铁有限公司 | Method for improving yield of low-carbon high-microalloyed steel |
| CN113154874A (en) * | 2021-04-14 | 2021-07-23 | 鞍钢股份有限公司 | Heating furnace low NOx combustion control method based on gas fuel |
| CN114214500A (en) * | 2021-12-20 | 2022-03-22 | 重庆钢铁股份有限公司 | Heating process of three-pass heating furnace |
| CN114214506A (en) * | 2022-02-21 | 2022-03-22 | 山西太钢不锈钢精密带钢有限公司 | Low-nitrogen combustion method for vertical annealing furnace |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101839638A (en) * | 2010-04-29 | 2010-09-22 | 北京首钢国际工程技术有限公司 | Heat accumulating and preheating combined heating method of slag-drip high-temperature silicon steel plate blank heating furnace |
| CN201634740U (en) * | 2010-03-30 | 2010-11-17 | 权芳民 | Series-type heating furnace before rolling of stainless steel billet |
| CN102634651A (en) * | 2011-02-11 | 2012-08-15 | 宝山钢铁股份有限公司 | Heating method of weak, micro-oxidation and oxidation combustion for ferrous metal steel slab |
| CN103062790A (en) * | 2012-12-29 | 2013-04-24 | 聚光科技(杭州)股份有限公司 | Method for controlling combustion inside heating furnace |
| CN104060080A (en) * | 2013-11-01 | 2014-09-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Heating control method and system of steel rolling heating furnace plate blank |
| CN106370021A (en) * | 2016-08-29 | 2017-02-01 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Control method for air-fuel ratio of pusher heat accumulating type heating furnace |
| CN106694567A (en) * | 2016-11-22 | 2017-05-24 | 首钢京唐钢铁联合有限责任公司 | Heating method for IF steel in ferrite rolling |
| CN110252809A (en) * | 2019-07-01 | 2019-09-20 | 山西太钢不锈钢股份有限公司 | The method of chrome ferritic stainless steel rough surface band in reduction |
-
2020
- 2020-03-03 CN CN202010140611.1A patent/CN111412755A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201634740U (en) * | 2010-03-30 | 2010-11-17 | 权芳民 | Series-type heating furnace before rolling of stainless steel billet |
| CN101839638A (en) * | 2010-04-29 | 2010-09-22 | 北京首钢国际工程技术有限公司 | Heat accumulating and preheating combined heating method of slag-drip high-temperature silicon steel plate blank heating furnace |
| CN102634651A (en) * | 2011-02-11 | 2012-08-15 | 宝山钢铁股份有限公司 | Heating method of weak, micro-oxidation and oxidation combustion for ferrous metal steel slab |
| CN103062790A (en) * | 2012-12-29 | 2013-04-24 | 聚光科技(杭州)股份有限公司 | Method for controlling combustion inside heating furnace |
| CN104060080A (en) * | 2013-11-01 | 2014-09-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Heating control method and system of steel rolling heating furnace plate blank |
| CN106370021A (en) * | 2016-08-29 | 2017-02-01 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Control method for air-fuel ratio of pusher heat accumulating type heating furnace |
| CN106694567A (en) * | 2016-11-22 | 2017-05-24 | 首钢京唐钢铁联合有限责任公司 | Heating method for IF steel in ferrite rolling |
| CN110252809A (en) * | 2019-07-01 | 2019-09-20 | 山西太钢不锈钢股份有限公司 | The method of chrome ferritic stainless steel rough surface band in reduction |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112146458A (en) * | 2020-09-09 | 2020-12-29 | 武汉钢铁有限公司 | Method for improving yield of low-carbon high-microalloyed steel |
| CN113154874A (en) * | 2021-04-14 | 2021-07-23 | 鞍钢股份有限公司 | Heating furnace low NOx combustion control method based on gas fuel |
| CN113154874B (en) * | 2021-04-14 | 2023-03-03 | 鞍钢股份有限公司 | Heating furnace low NOx combustion control method based on gas fuel |
| CN114214500A (en) * | 2021-12-20 | 2022-03-22 | 重庆钢铁股份有限公司 | Heating process of three-pass heating furnace |
| CN114214506A (en) * | 2022-02-21 | 2022-03-22 | 山西太钢不锈钢精密带钢有限公司 | Low-nitrogen combustion method for vertical annealing furnace |
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Application publication date: 20200714 |