CN115218670A - Method for auxiliary sintering by alternately blowing gas and water vapor - Google Patents
Method for auxiliary sintering by alternately blowing gas and water vapor Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 95
- 238000007664 blowing Methods 0.000 title claims description 15
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B21/00—Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
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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
- F27D19/00—Arrangements of controlling devices
-
- 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
- F27D7/00—Forming, maintaining, or circulating atmospheres in heating chambers
- F27D7/02—Supplying steam, vapour, gases, or liquids
-
- 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
- F27D19/00—Arrangements of controlling devices
- F27D2019/0028—Regulation
- F27D2019/0034—Regulation through control of a heating quantity such as fuel, oxidant or intensity of current
- F27D2019/004—Fuel quantity
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Abstract
A method for auxiliary sintering by interval injection of fuel gas and water vapor is characterized in that: injecting gas and water vapor to the surface of the sintering mixture at periodic intervals, wherein the gas enters the sintering mixture layer for combustion and heat supply, and the water vapor enters the sintering mixture layer for water gas reaction with carbon in the solid fuel to accelerate the combustion of the solid fuel; in the process of gas injection, the temperature of the sintering ore zone and the combustion zone area in the sintering material layer is controlled by adjusting the time length of gas injection in a single period. According to the invention, through periodic interval injection of gas and water vapor, ignition and flameout of the gas can be controlled to repeatedly occur at the position of the sintering ore zone close to the combustion zone, so that an excessively thick red layer caused by overhigh temperature in a corresponding area is avoided, and the technical problems of poor material layer air permeability, negative pressure rise of sintering air draft and the like caused by improvement of the gas injection quantity are effectively avoided.
Description
Technical Field
The invention relates to a gas injection auxiliary sintering process, in particular to a gas and water vapor interval injection auxiliary sintering method, and belongs to the technical field of sintering.
Background
Due to CO 2 And due to greenhouse effect caused by gases, glaciers melt, sea level rises, natural ecology degeneration and natural disasters frequently occur, and the lives of human beings in partial regions are directly threatened. Along with the annual increase of the steel yield in China, the total carbon emission of the steel industry in China is on the trend of increasing year by year, the annual carbon emission is more than ten thousand, and CO in the steel industry 2 Emission reduction tasks face tremendous pressure.
As a key link in the iron-making process in the iron and steel industry, the sintering process mainly has the main functions of mixing various powdery iron-containing raw materials with proper amount of fuel and flux, adding proper amount of water, mixing and pelletizing, enabling the materials to generate a series of physical and chemical changes on sintering equipment, sintering the materials into blocks, and conveying the blocks to a blast furnace for the next working procedure.
According to the relevant data, the carbon dioxide emission of sintering and blast furnace processes accounts for about 60% of the total industrial emission. In order to reduce carbon emission in the sintering process and the subsequent blast furnace smelting cost, the blast furnace usually has high strength and high reducibility on sintered ores. In the sintering process, the sintered ore is generally required to have higher strength, high yield, lower return fines rate and lower fuel consumption. The high-strength and high-reducibility sintered ore consumes less coke in the blast furnace smelting process, thereby reducing the emission of carbon dioxide.
After the pulverized coal of the upper material layer is ignited in the sintering process, the combustion heat release is used for sintering nearby raw materials and air draft type operation production, the heat of the upper part is brought into the lower material layer by gas through the self-heat-storage effect to participate in the sintering of the lower material layer, and therefore the heat required by the material layer from top to bottom is gradually reduced. Segregation material distribution is adopted during material distribution, the amount of coal powder distributed on the upper material layer is large, and the amount of coal powder distributed on the lower material layer is small. The method can greatly improve the quality index of the finished product under the same fuel consumption index, or greatly reduce the fuel consumption index under the same finished product quality index, thereby achieving the purposes of saving energy and reducing carbon emission.
However, due to the limitation of the device technology, the strict ideal layered segregation type fuel distribution is difficult to realize in the actual industrial production of the sintering plant, and the owners have to distribute the solid fuel according to the high value of the theoretical required fuel quantity in each layer. Meanwhile, some large-particle coke powder can roll down to the bottom of the material layer when the sintering machine head distributes the material, and the opposite situation that the lower solid fuel quantity is high and the middle and upper solid fuel quantity is low can be caused. The problem that the upper material layer heat is insufficient and the middle and lower material layers heat is excessive can be caused in the sintering material layer during sintering production, the lower sintering material is easy to melt, and the like, so that energy and resource waste is caused and the generation of smoke pollutants is greatly intensified.
Under the large environment, the technology of 'sintering charge level gas fuel injection' developed by the Japan JFE company comes into force, natural gas fuel diluted to be below the lower limit of combustible concentration is injected above the sintering charge level at a distance behind an ignition furnace, and is combusted and supplied heat in a sintering charge layer, so that the solid carbon consumption and CO in the production of sintering ore are reduced 2 And (4) discharging the amount. Meanwhile, the combustion of the gas fuel widens the width of a high-temperature belt of a sinter bed during production, so that the temperature time of the sinter at 1200-1400 ℃ is prolonged, and the sintering time is shortenedSo that the strength and the porosity of 5-10 mm of the sintered ore are effectively enhanced.
In the initial sintering process, the distribution of the material layer in the sintering process is shown in fig. 3, the material layer on the trolley mainly comprises a sintering ore belt, a combustion belt, a drying preheating belt, an over-wet belt and an original material belt from top to bottom, and the approximate temperature distribution is shown by a curve corresponding to 'non-adopted injection' in fig. 4. The burning zone is at a high temperature because the coke powder in the sintering material layer is ignited, the physicochemical processes of melting, sintering and the like of minerals are realized at 1200-1400 ℃, finished sintering ore is formed (the burning zone is changed into a sintering ore zone), and the burning of the coke powder is finished at the moment. Due to the influence of the air draft, fresh air is continuously supplemented to the top of the material bed to cool the material bed, so that the temperature of the sinter band is low at a position close to the top of the material bed and high at a position close to a combustion zone.
After the gas injection technology is adopted, the combustion of the gas fuel widens the width of a high-temperature zone of a sinter bed during production, and slows down the cooling speed of fresh air on sintered finished ore, so that the temperature of the position, close to a combustion zone, in the sinter ore zone is higher than that of the sinter ore zone without injection, and the effect is shown as a curve corresponding to injection in figure 4. The laboratory research and sintering process engineering practice shows that in a certain range, the larger the gas injection amount and the injection concentration are, the more heat is released after the gas is absorbed into a material layer, the larger the solid fuel quantity is replaced, and therefore, the lower coke consumption and the lower CO are realized 2 And (5) discharging. Generally, the higher the combustible gas concentration in the mixed gas is, the lower the ignition temperature is, and therefore, it can be found from the temperature distribution in the charge bed that, after increasing the injection amount of the gas and increasing the injection concentration, the position where the gas ignites in the charge bed moves from a position near the burning zone to the direction of the burning zone, and the temperature profile in the charge bed shows that the temperature is higher at the position near the burning zone as shown by the broken line in fig. 5. The "red layer" is used to describe the region with the temperature in the sintering material layer above about 1000 deg.C, obviously, after the gas injection quantity is raised, the thickness of the red layer in the material layer is obviously increased, and because the temperature in the red layer is high and the liquid phase is generated, the red layer is too thickThe air permeability of the material layer is poor, the negative pressure of sintering air draft is too large, the air quantity passing through the material layer and the sintering process are influenced, and the yield and the quality of sintered ore are reduced.
In addition, when the gas injection amount is increased and the solid fuel ratio is reduced to a certain degree, the air permeability and the air draft negative pressure of a sinter bed are deteriorated, the sintering speed is also reduced, the sintering utilization coefficient is reduced, and the economic index of production is influenced.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method for auxiliary sintering by alternately blowing gas and water vapor. The invention aims to solve the technical problems of poor air permeability of a material layer, rising negative pressure of sintering air draft, slowing down sintering speed and the like after the gas injection quantity is increased in the gas injection auxiliary sintering process, and realizes the maximum gas injection quantity under the condition of maintaining the normal air permeability, negative pressure of air draft and sintering speed of the material layer, thereby more obviously increasing the substitute quantity of solid fuel, reducing CO and the like 2 And (5) discharging.
The invention provides a method for continuously injecting fuel gas in the fuel gas injection process, which changes the original method for continuously injecting fuel gas into the fuel gas injection process, and uses the measures of injecting fuel gas and water vapor at intervals to inject the fuel gas and the water vapor into a material layer of a sintering mixture at intervals. According to the invention, the intermittent injection and stop of the fuel gas are skillfully controlled by the interval injection of the fuel gas and the water vapor, so that the fuel gas is repeatedly ignited and extinguished near the combustion zone, thereby ensuring that an excessively thick red layer caused by overhigh temperature can not appear at the positions of the combustion zone and the sintering ore zone, and effectively avoiding the technical problems of poor material bed air permeability, negative pressure rise of sintering air draft and the like. Meanwhile, the injected steam can accelerate the ignition and combustion of the solid fuel in the combustion zone and the unburned material layer and accelerate the downward movement of the front of the combustion zone, thereby improving the sintering speed and the sintering utilization coefficient.
According to an embodiment of the invention, a method of gas-steam space injection assisted sintering is provided.
A method for assisting sintering by injecting fuel gas and water vapor at intervals comprises the steps of periodically injecting fuel gas and water vapor at intervals to the surface of a sintering mixture, enabling the fuel gas to enter a sintering material layer for combustion and heat supply, enabling the water vapor to enter the sintering material layer to generate water gas reaction with carbon in solid fuel, and accelerating the combustion of the solid fuel. In the process of gas injection, the temperature of a sintering ore zone and a combustion zone area in a sintering material layer is controlled by adjusting the time length of gas injection in a single period.
Along the thickness direction of the sinter bed, the sinter bed on the sintering trolley mainly comprises a sinter ore zone, a combustion zone, a drying preheating zone, an over-wet zone and an original material zone from top to bottom in sequence.
In the invention, the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer comprises the following steps:
1) And determining the number of cycles for injecting the fuel gas, the time length for initially injecting the fuel gas in a single cycle and the time length for initially injecting the water vapor in the single cycle.
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
4) And calculating the heat released by the combustion of the injected fuel gas in the sintering material layer in the fuel gas injection time of a single period.
5) And calculating the cooling amount of the mixed gas of the water vapor and the air on the sinter layer in the water vapor blowing time of a single period.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, and further realizing the control of the temperature of the sinter band and the combustion band area in the sinter bed.
In the present invention, step 1) comprises the following substeps:
1a) Calculating the operation time t of the sintering trolley in the gas injection section according to the length L of the gas injection section on the sintering machine and the operation speed v of the sintering trolley, namely the total time t for injecting gas and water vapor to the sintering mixture in the sintering trolley is as follows:
1b) Setting the number of cycles for injecting gas into the sintering mixture in the sintering trolley to be N and the time length for initially injecting gas in a single cycle to be delta t 1 Whereby the time period deltat for the initial injection of water vapor in a single cycle 2 Comprises the following steps:
in the invention, in step 2), the total amount of gas to be injected into the sintering mixture in the sintering pallet is as follows:
in the formula: g 1 The total amount of gas to be blown for sintering the mixture in the sintering pallet. And m is the quality of the sintering mixture in the corresponding area of the gas injection section. Q Supplement device The heat quantity is needed to be supplemented for the sintering mixture of unit mass after the solid fuel proportioning is reduced integrally. Wherein Q Supplement device Is determined by the types of sintering raw materials, the average particle size of sintering mixture, the solid fuel ratio and the like. H is the heat value of the fuel gas.
Preferably, in step 2), the calculating the injection amount of the fuel gas per unit time specifically includes:
in the formula: s. the 1 Is the amount of gas injected per unit time.
In the invention, in step 3), the total amount of water vapor required to be injected into the sinter mixture in the sintering pallet is as follows:
G 2 ＝m×R carbon (C) ×γ…………(5)。
In the formula: g 2 The total amount of water vapor that needs to be blown for sintering the mix in the sintering pallet. And m is the quality of the sintering mixture in the corresponding area of the gas injection section. R Carbon (C) Is the proportion of solid carbon fuel in the sinter mix. Gamma is the proportional coefficient of water vapor/solid carbon fuel, and the value range of gamma is 3.6-5.4 m 3 /kg。
Preferably, in step 3), the calculating the blowing amount of the water vapor per unit time specifically includes:
in the formula: s 2 The amount of water vapor injected per unit time is shown.
In the present invention, in step 4), the heat released by the combustion of the injected fuel gas in the sintering bed is calculated within the single period of fuel gas injection time, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
In the present invention, in step 5), the amount of cooling the sinter layer by the mixed gas of water vapor and air is calculated within the water vapor injection time of a single cycle, specifically: water vapor injection time deltat in a single cycle 2 The sinter bed is cooled by a mixed gas of water vapor and air at a cooling rate of q co Namely, the following steps are provided:
q co ＝h co ·(T burning of -T Steaming/emptying )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 The cooling amount of the oxygen-enriched gas to the sinter bed in the time.h co Is determined according to the heat exchange experience of water vapor and high-temperature solid for the cooling coefficient of a sinter bed h co The value range of (A) is 90-110W/(m) 2 ·℃)。T Burning of The combustion temperature of the fuel gas in the sintering material layer is generally selected within the range of 1000-1200 ℃ according to experience. T is Steaming/emptying The temperature of the mixed gas of water vapor and air entering the material layer is 450 ℃, 445 ℃ or 440 ℃, for example. And m is the quality of the sintering mixture in the corresponding area of the gas injection section. A is the specific surface area of the combustion zone in the sintering material layer. Xi is the proportion of the combustion zone in the height direction to the height of the whole sinter bed, and the value range of xi is 0-1, preferably 0.01-0.1.
In the present invention, step 6) includes the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter bed at the corresponding position in a single period:
c p ·ξ·m·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter bed.
6b) Calculating the actual final temperature T of the sinter bed at the corresponding position in a single period co ：
T co ＝T Burning of +ΔT…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the time length of gas injection in a single period, thereby realizing the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer.
Preferably, substep 6 c) is specifically:
if the actual final temperature T of the sinter bed in a single cycle co = target temperature T aim The temperature of the sintering ore zone and the combustion zone is controlled within a normal range in the period, and the system is maintained as the sameThe former blowing parameters continue to run.
If the actual final temperature T in a single cycle co Greater than target temperature T aim At this time, the time length of gas injection in a single period is shortened, so that T co ＝T aim 。
If the actual final temperature T in a single cycle co < target temperature T aim At the moment, the time length of gas injection in a single period is prolonged, so that T co ＝T aim 。
Preferably, in sub-step 6 c), said target temperature T aim The value range of (A) is 600-1000 ℃, preferably 700-850 ℃, and more preferably 740-780 ℃.
Generally, in the initial sintering process, the material layers in the sintering process mainly comprise a sintering ore belt, a combustion belt, a drying preheating belt, an over-wet belt and an original material belt from top to bottom in sequence. Wherein, the burning zone has higher temperature because the coke powder in the sintering material layer is ignited, the physicochemical processes of mineral melting, sintering and the like are realized at 1200-1400 ℃, the finished product sintering ore is formed, namely, the burning zone is converted into a sintering ore zone, and the burning of the coke powder is finished. Due to the influence of air suction in the air suction type sintering, fresh air can be continuously supplemented to the top of the material layer to cool the material layer, so that the temperature of the sintering ore zone is low at a position close to the top of the material layer and high at a position close to a combustion zone.
In the prior art, to reduce CO during sintering 2 The technology of gas injection auxiliary sintering is provided. Gas fuel diluted to below the lower limit of combustible concentration is sprayed above the sintering charge level and is combusted in the sintering charge layer to supply heat, so that the solid carbon consumption and CO in the production of sintered ore are reduced 2 And (4) discharging the amount. In fig. 4, the temperature distribution of the sinter layer in the sintering process is compared between the case of using the gas injection technique and the case of not using the gas injection technique. The temperature distribution of the sinter bed not adopting the gas injection technology in the sintering process is shown by a curve corresponding to 'not adopting injection' in fig. 4, and the temperature distribution of the sinter bed adopting the gas injection technology is shown by a curve corresponding to 'adopting injection' in fig. 4. Root of herbaceous plantAs can be seen from fig. 4, after the gas injection technique is adopted, the combustion of the gas fuel widens the width of the high-temperature zone of the sinter bed during production, and slows down the cooling speed of fresh air on the sintered finished ore, so that the temperature in the sinter bed near the combustion zone is higher than the temperature when the injection is not adopted.
For further reduction of CO 2 The laboratory research and the sintering process engineering practice find that in a certain range, the larger the gas injection amount and the higher the injection concentration are, the more the heat released after the gas is absorbed into a material layer is, the larger the substituted solid fuel amount is, so that the less coke consumption is realized, namely, the less CO is realized 2 And (4) discharging. The temperature distribution of the sinter bed after increasing the injection amount of the fuel gas and increasing the injection concentration is shown by the dotted line in fig. 5. As can be seen from fig. 5, after the injection amount of the fuel gas is increased and the injection concentration is increased, the ignition position of the fuel gas in the material bed moves from the position near the burning zone to the direction of the burning zone, that is, the temperature of the burning zone is higher. The 'red layer' is used for describing the region with the temperature in the sintering material layer being above about 1000 ℃, obviously, after the gas injection amount is increased, the thickness of the red layer in the material layer is obviously increased, and because the temperature in the red layer is high and liquid phase is generated, the excessively thick red layer can cause poor air permeability of the material layer and overlarge negative pressure of sintering air draft, influence the air quantity passing through the material layer and the sintering process, and reduce the yield and quality of sintering ores. In addition, when the gas injection amount is increased and the solid fuel ratio is reduced to a certain degree, the air permeability and the air draft negative pressure of a sinter bed are deteriorated, the sintering speed is also reduced, the sintering utilization coefficient is reduced, and the economic index of production is influenced. That is, the amount of solid carbon and CO used in the production of sintered ore is reduced due to the increase of the gas injection amount in the gas injection auxiliary sintering process 2 The discharge amount, however, brings new technical problems.
In the prior art, the conventional method of sintering by using a gas injection technology, or the method of sintering by injection after increasing the injection amount of gas and increasing the injection concentration, both adopt the method of continuously injecting (or injecting) gas to the sintering charge levelThe method of (1). The invention provides a method for auxiliary sintering by intermittently injecting gas and water vapor, aiming at the problems in auxiliary sintering by continuously injecting gas after increasing the injection amount and the injection concentration of the gas in the prior art. The method changes the original method of continuously injecting fuel gas in the fuel gas injection process, and uses the measures of injecting fuel gas and water vapor at intervals to inject the fuel gas and the water vapor into the material layer of the sintering mixture at intervals in order. As shown in FIG. 6, in the present invention, gas injection Δ t 1 After a long time, the water vapor is used for blowing delta t 2 For a long time, then continuing to inject the gas Δ t 1 Duration, blowing of water vapour delta t 2 Its time length is 8230, so that it can be cyclically used. Wherein the injection gas Δ t 1 Duration + injected steam Δ t 2 The duration is one injection period and is continuously repeated in the whole process of sintering and injecting the fuel gas. Gas injection duration at a single cycle Δ t 1 Because of the injection of the fuel gas, the fuel gas is ignited and burnt at the position of the area near the burning zone and the sintering ore zone to release heat; duration of water vapour injection at a single cycle Δ t 2 Interior, owing to do not have the jetting of gas to mend, the position of gas burning then can extinguish fire originally, because the benefit of vapor this moment, the temperature of the mist of vapor and air is less than the sintering ore area and the near burning area temperature of the area of igniting the heat release originally of burning to play the cooling effect to this region. That is to say, through the gas and the periodic interval jetting of vapor, can control the sintering ore area near the burning zone position take place catching fire, flame-out of gas repeatedly to guarantee that the corresponding region can not appear the high temperature and cause too thick red layer, and then effectively avoided improving the relatively poor, sintering convulsions negative pressure of bed of material gas permeability that bring behind the gas injection volume technical problem such as rise. Furthermore, the invention determines a proper injection system by adjusting parameters of the injected fuel gas (such as the periodicity of the injected fuel gas, the time length of the injected fuel gas in a period, the time length of the injected water vapor in the period and the like), thereby improving the temperature change curve of the sintered ore zone and the area near the combustion zone on the premise of maintaining the original fuel gas supplement amount (namely the existing increased fuel gas injection amount), weakening the thickness of the red layer, and ensuring proper bed permeability and normal extractionWind negative pressure, and maximum gas injection amount under the condition of maintaining the air permeability of the material layer and normal air draft negative pressure, thereby more obviously improving the solid fuel substitution amount and reducing CO 2 And (5) discharging.
It is noted that, in the present invention, the injected water vapor has a cooling effect, and after entering the sinter bed, the water vapor reacts with carbon in the solid fuel in a high-temperature region of the combustion zone (i.e. a position close to the combustion center) through water gas reaction: h 2 O(g)+C(s)→CO(g)+H 2 (g) .1. The CO and H produced by the water gas reaction 2 Can react with air quickly, so as to accelerate the burning speed of solid fuel (such as coke powder), accelerate the downward moving speed of the combustion zone front and further improve the sintering speed and the sintering utilization coefficient. Laboratory research and production practice prove that the water gas reaction between the injected water vapor and carbon can change the reaction path of coke powder combustion, so that the carbon combustion is more complete, and CO in the product is improved 2 The selectivity of (2) and the concentration of CO in the flue gas are reduced.
In the invention, the method for the gas steam interval injection auxiliary sintering firstly determines the initial parameters of the injected gas, wherein the initial parameters of the injected gas comprise the cycle number N of the injected gas and the time length delta t of the initially injected gas in a single cycle 1 Duration Deltat of initial injection of water vapor in a single cycle 2 The amount S of gas injected per unit time 1 (i.e., the gas injection flow rate), and the amount S of steam injected per unit time 2 (i.e., the water vapor injection flow rate). After the initial parameters of the injected fuel gas are determined, the fuel gas and the water vapor are periodically injected to the charge level of the sintering mixture at intervals according to the initial parameters. Gas enters the sintering material layer to be combusted for heat supply and auxiliary sintering; the water vapor enters the material layer to play a role in cooling, and simultaneously generates water gas reaction with carbon in the solid fuel to generate CO and H 2 And the reaction with air is rapidly carried out, so that the ignition and combustion of solid fuel in a combustion zone and an unburned material layer are accelerated, and the sintering speed is accelerated. Then calculating the heat Q released by the combustion of the injected fuel gas in the sintering material layer in a single period in And mixed gas of water vapor and air at delta t 2 Cooling capacity Q of the sinter bed over time co According to the heat balance principle, the temperature change condition of the sinter bed in a single period is judged, and accordingly, the control of the temperature of the sinter zone and the combustion zone area in the sinter bed is achieved. Wherein, the control to the sintering ore area in the sinter bed and the regional temperature of burning zone is realized according to the temperature change condition of sinter bed in single cycle, specifically includes: according to the heat balance principle, calculating the actual final temperature T of the sinter bed at the corresponding position of the gas injection in a single period co The actual final temperature T obtained by calculation co With a target temperature T aim And comparing the temperature of the sintering ore zone and the temperature of the combustion zone in the sintering material layer, and further adjusting the duration of gas injection in a single period, thereby realizing the control of the temperatures of the sintering ore zone and the combustion zone area in the sintering material layer and avoiding the conditions of overhigh temperature and over-thick red layer.
In the present invention, said target temperature T aim The critical temperature value is obtained according to laboratory research and practical experience summary of sintering engineering, and can enable the gas in the sintering ore zone and the combustion zone area in a single period to be extinguished. The target temperature T aim The range of values of (A) is 600-1000 ℃, preferably 700-850 ℃, more preferably 740-780 ℃. The invention determines a proper injection system by adjusting the cycle number of the injected fuel gas, the fuel gas injection time length in a single cycle and the steam injection time length in a single cycle, namely the final temperature in the cycle in the controllable type (12), thereby accurately controlling the trend of the temperature curve near the sintering ore zone and the combustion zone in the sintering process, ensuring that the temperature maintaining time in the sintering process is prolonged by the supplemented fuel gas but the temperature is not too slow due to the continuous supplement of the fuel gas, further weakening the thickness of a red layer, and ensuring that the air permeability of a material layer and the air draft negative pressure are in the optimal state. In the invention, if the actual final temperature T of the sinter bed at the corresponding position in a single period co = target temperature T aim That is, the actual final temperature of the sinter bed is within the range of the target temperature, and the gas extinction at the corresponding position of the sinter bed (i.e. the gas extinction at the corresponding position of the time gap of water vapor injection) indicates that the gas extinction is in the corresponding position of the injection cycleAnd controlling the temperature of the sintered ore zone and the combustion zone within a normal range, wherein the current injection parameter is the appropriate injection parameter, and the system keeps the current injection parameter to continuously operate. If the actual final temperature T of the sinter bed at the corresponding position in a single period co Greater than target temperature T aim The temperature of the sintered ore zone and the combustion zone area in the injection period is higher, and at the moment, the gas at the position corresponding to the sinter bed possibly has the condition of not extinguishing (namely the gas at the position corresponding to the time gap for injecting water vapor is not extinguished), and the conditions that the permeability of the sinter bed is influenced due to the over-thick red layer, the negative pressure of air draft is increased, and the sintering speed is reduced are possibly caused; the injection parameters need to be adjusted, for example, to shorten the time of injecting gas in a single period, or to increase the number of cycles of injecting gas, or to adjust the time of injecting gas and the number of cycles of injecting gas in a single period, so that T is co ＝T aim And further controlling the temperature of the sintering ore zone and the combustion zone to return to the normal range. If the actual final temperature T of the sinter bed at the corresponding position in a single period co < target temperature T aim At this time, the gas at the position corresponding to the sinter bed is extinguished (namely, the gas at the position corresponding to the time gap of water vapor injection is extinguished), which indicates that the temperature of the sintering zone and the combustion zone is low in the injection period, and the normal operation of sintering and the quality of sintering are possibly influenced; the injection parameters may need to be adjusted, for example, to extend the duration of gas injection in a single cycle, or to reduce the number of cycles of gas injection, or to adjust both the duration of gas injection and the number of cycles of gas injection in a single cycle, such that T is co ＝T aim And further controlling the temperature of the sintering ore zone and the combustion zone to return to the normal range.
In the process of adjusting the period of time for which gas is injected and/or the number of cycles for which gas is injected in a single cycle according to the present invention, when the period of time for which gas is injected in a single cycle is adjusted (extended or shortened), the period of time for which water vapor is injected in a single cycle needs to be adjusted (shortened or extended) synchronously in the adjustment process because the number of cycles for which gas is injected is not changed at that time. When only the number of cycles of gas injection is adjusted (increased or decreased), since thenThe time length of the gas injection in a single period is not changed, so that the time length of the water vapor injection in the single period needs to be synchronously adjusted (shortened or prolonged) in the adjustment process. When the time length of gas injection and the cycle number of the gas injection in a single period are adjusted simultaneously, the time length of water vapor injection in the single period also needs to be adjusted synchronously. Further, according to the formula (4), the amount of gas injected per unit time
Therefore, when the time length of gas injection and/or the number of cycles of gas injection in a single cycle are/is adjusted, the injection amount of gas in unit time is synchronously adjusted correspondingly. According to the formula (6), i.e. the amount of water vapor injected per unit time
Therefore, when the time length of gas injection and/or the number of cycles of gas injection in a single cycle are/is adjusted, correspondingly, the injection amount of water vapor in unit time is also synchronously adjusted.
In the invention, the total amount of fuel gas required to be injected into the sintering mixture in the sintering trolley
Wherein Q is Supplement device The amount of the gas to be blown into the sintering material in the sintering pallet is determined by the kind of the sintering material, the average particle size of the sintering material, the proportion of the solid fuel in the sintering material, the kind of the gas, and the like.
In the invention, the total amount G of water vapor required to be injected into the sinter mixture in the sintering pallet 2 ＝m×R Carbon (C) The x γ is the total amount of steam to be injected into the sinter mix in the sintering pallet, and is related to the mass of the sinter mix, the ratio of solid fuel in the sinter mix, and the ratio coefficient of steam to solid carbon fuel.
Single week in the present inventionDelta t of injected steam 2 In the time zone, the temperature of the area where the burning fire and heat release originally occurred in the vicinity of the sintering zone and the combustion zone is temporarily lowered due to the quenching of the gas and the cooling of the mixed gas of the water vapor and the air after the water vapor is injected. The cooling rate q of the sinter bed cooled by the mixed gas of water vapor and air co ＝h co (T Burning of -T Steaming/emptying ) Where xi x m x a, it can be seen that the cooling rate is related to the sinter bed cooling coefficient, the gas combustion temperature, the water vapor temperature, the ambient temperature, the internal surface area of the sinter bed, the proportion of the combustion zone in the height direction to the height of the entire bed, and the like. In addition, in the present application, the specific values of the parameters involved in formulas (1) - (12) can be obtained by detection, calculation or according to production experience.
It should be noted that the cycle number of the injected gas, the total amount of the gas to be injected into the sinter mix in the sintering pallet, and the total amount of the water vapor to be injected into the sinter mix in the sintering pallet are all based on the sinter mix in the region corresponding to the gas injection segment. The cycle number of the injected gas refers to the number of times of injecting gas and water vapor when the sintering mixture passes through the gas injection section. The total amount of gas to be injected into the sintering mixture in the sintering trolley is based on the realization of the maximum gas injection amount, so that the solid fuel substitution amount is increased, and the CO is reduced 2 On the premise of emission, the amount of gas required to be injected by the sintering mixture is increased. The total amount of steam to be injected into the sintering mixture in the sintering pallet is based on the cooling effect of the mixed gas of the steam and air on a gas combustion area and the premise that the steam and carbon generate water gas reaction to accelerate the combustion speed of the solid fuel and improve the sintering speed, and the steam to be injected into the sintering mixture is required to be injected.
In addition, since the "red layer" means a region in which the temperature in the sintering material layer is about 1000 ℃ or higher, and the region in which the temperature in the sintering material layer is 1000 ℃ or higher is mainly concentrated in the combustion zone and a partial region of the sintering ore zone close to the combustion zone, the present application realizes the control of the thickness of the red layer by controlling the temperatures of the sintering ore zone and the combustion zone region in the sintering material layer, and mainly controls the temperature of the upper region of the combustion zone and the temperature of the sintering ore zone close to the combustion zone within a reasonable range in the thickness direction of the material layer.
In the present application, the terms "gas combustion position", "position near gas combustion", and "corresponding position" have the same meaning.
Compared with the prior art, the invention has the following beneficial technical effects:
1. the invention changes the existing method for continuously injecting fuel gas, adopts periodic interval injection measures, skillfully controls the injection and the stop of the fuel gas through the interval injection of the fuel gas and water vapor, further ensures that the fuel gas is repeatedly ignited and extinguished near a combustion zone, and leaves a certain cooling time for sintering finished ore in a specific area while supplementing heat through a fuel gas feeding layer, thereby being capable of controlling the temperature of the combustion zone and the sintering ore zone without overhigh temperature.
2. The invention can control the final temperature in the period of the sinter bed by selecting and adjusting the cycle number of the injected fuel gas, the fuel gas injection time length in a single period and the steam injection time length in a single period and determining a proper injection system, thereby accurately controlling the trend of the temperature curve near the sinter bed and the combustion zone in the sintering process, ensuring that the temperature maintaining time in the sintering process is prolonged by the supplemented fuel gas but the temperature is not too slow due to the continuous supplement of the fuel gas, further weakening the thickness of a red layer, and ensuring that the air permeability of the bed and the air draft negative pressure are in the optimal state.
3. According to the invention, a method of periodically injecting gas and water vapor at intervals is adopted, the injected water vapor plays a role in cooling a gas combustion area, and meanwhile, the injected water vapor can generate a water-gas reaction with carbon in solid fuel, so that the combustion of the solid fuel is accelerated, the moving speed of a combustion zone front is increased, and the problems of greatly increasing the gas injection amount, reducing the post-sintering speed of the solid fuel and reducing the sintering utilization coefficient are solved; the water gas reaction changes part of the solid fuel combustion reaction path, so that carbon is combusted more completely, and the concentration of CO in the flue gas is reduced.
4. The invention realizes the maximum gas injection amount in the sintering process under the condition of maintaining the air permeability, the negative pressure of air draft and the normal sintering speed of the material layer, thereby realizing the substitution of solid fuel and CO with larger proportion 2 And (5) emission reduction.
Drawings
FIG. 1 is a schematic diagram of a method for sintering by gas-steam interval blowing assistance according to the invention;
FIG. 2 is a flow chart of a method for sintering by gas-steam interval injection auxiliary sintering according to the present invention;
FIG. 3 is a bed distribution diagram of a sinter mix;
FIG. 4 is a graph showing the temperature of the sinter bed in the case of gas injection and in the case of no gas injection;
FIG. 5 is a graph showing the temperature of a sinter bed in two cases of increasing the gas injection concentration and adopting the conventional gas injection;
FIG. 6 is a schematic view of the present invention with periodic intervals of gas and water vapor injection;
FIG. 7 is a graph showing the temperature of the sinter bed in the case of the intermittent injection of fuel gas steam and the case of the conventional continuous injection of fuel gas.
Reference numerals are as follows:
1: sintering the trolley; a1: sintering the ore belt; a2: a combustion zone; a3: drying the preheating zone; a4: an overwetting belt; a5: an original material tape.
Detailed Description
According to an embodiment of the invention, a method of gas-steam space injection assisted sintering is provided.
A method for assisting sintering by injecting fuel gas and water vapor at intervals comprises the steps of periodically injecting fuel gas and water vapor at intervals to the surface of a sintering mixture, enabling the fuel gas to enter a sintering material layer for combustion and heat supply, enabling the water vapor to enter the sintering material layer to generate water gas reaction with carbon in solid fuel, and accelerating the combustion of the solid fuel. In the process of gas injection, the temperature of the sintering ore zone and the combustion zone area in the sintering material layer is controlled by adjusting the time length of gas injection in a single period.
Along the thickness direction of the sinter bed, the sinter bed on the sintering trolley mainly comprises a sinter ore belt A1, a combustion belt A2, a drying preheating belt A3, an overwetting belt A4 and an original material belt A5 from top to bottom.
In the invention, the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer comprises the following steps:
1) And determining the number of cycles for injecting the fuel gas, the time length for initially injecting the fuel gas in a single cycle and the time length for initially injecting the water vapor in the single cycle.
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
4) And calculating the heat released by the combustion of the injected fuel gas in the sintering bed within the fuel gas injection time of a single period.
5) And calculating the cooling quantity of the mixed gas of the water vapor and the air to the sinter bed in the water vapor injection time of a single period.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, thereby realizing the control of the temperature of the sinter band and the combustion band area in the sinter bed.
In the present invention, step 1) comprises the following substeps:
1a) Calculating the operation time t of the sintering pallet in the gas injection section according to the length L of the gas injection section on the sintering machine and the operation speed v of the sintering pallet, namely the total duration t of injecting gas and water vapor to the sintering mixture in the sintering pallet is as follows:
1b) Setting the number of cycles of gas injection to the sintering mixture in the sintering trolley to be N andthe time length of initial gas injection in each period is delta t 1 Whereby the time period deltat for the initial injection of water vapor in a single cycle 2 Comprises the following steps:
in the invention, in step 2), the total amount of gas to be injected into the sintering mixture in the sintering pallet is:
in the formula: g 1 The total amount of gas to be injected for sintering the mixture in the sintering pallet. And m is the quality of the sintering mixture in the corresponding area of the gas injection section. Q Supplement device The heat quantity needs to be supplemented for the sintering mixture of unit mass after the solid fuel proportion is reduced integrally. Wherein Q is Supplement device Is determined by the types of sintering raw materials, the average particle size of sintering mixture, the solid fuel ratio and the like. H is the heat value of the fuel gas.
Preferably, in step 2), the calculating the injection amount of the fuel gas in unit time includes:
in the formula: s 1 Is the amount of gas injected per unit time.
In the invention, in step 3), the total amount of water vapor required to be injected into the sinter mixture in the sintering pallet is as follows:
G 2 ＝m×R carbon (C) ×γ…………(5)。
In the formula: g 2 The total amount of water vapor required to be blown for sintering the mixture in the sintering pallet. And m is the mass of the sintering mixture in the corresponding area of the gas injection section. R Carbon (C) Is the proportion of the solid carbon fuel in the sinter mix. Gamma is the proportionality coefficient of water vapor/solid carbon fuel, and the value range of gamma is 3.6 to5.4m 3 /kg。
Preferably, in step 3), the calculating the blowing amount of the water vapor in the unit time includes:
in the formula: s. the 2 The amount of water vapor injected per unit time is shown.
In the invention, in step 4), the heat released by the combustion of the injected fuel gas in the sintering bed is calculated within the single period of fuel gas injection time, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
In the present invention, in step 5), the amount of cooling the sinter layer by the mixed gas of water vapor and air is calculated within the water vapor injection time of a single cycle, specifically: water vapor injection time deltat in a single cycle 2 The cooling rate of the sinter bed by the mixed gas of water vapor and air is q co Namely, the following steps are provided:
q co =h co ·(T burning of -T Steam/air )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 The cooling amount of the oxygen-enriched gas to the sinter bed in the time. h is a total of co The cooling coefficient of the sinter bed is determined according to the heat exchange experience of water vapor and high-temperature solid, h co The value range of (a) is 90-110W/(m) 2 ·℃)。T Burning of The combustion temperature of the fuel gas in the sintering material layer is generally selected within the range of 1000-1200 ℃ according to experience. T is a unit of Steaming/emptying The temperature of the mixed gas of water vapor and air entering the material layer is 450 ℃, 445 ℃ or 440 ℃, for example. And m is the quality of the sintering mixture in the corresponding area of the gas injection section. A is the specific surface area of the combustion zone in the sintering material layer. Xi is the proportion of the combustion zone in the height direction to the height of the whole sinter bed, and the value range of xi is 0-1, preferably 0.01-0.1.
In the present invention, step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter bed at the corresponding position in a single period:
c p ·ξ·m·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter bed.
6b) Calculating the actual final temperature T of the sinter bed at the corresponding position in a single period co ：
T co ＝T Burning of +ΔT…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the duration of gas injection in a single period, thereby realizing the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer.
Preferably, substep 6 c) is specifically:
if the actual final temperature T of the sinter bed in a single cycle co = target temperature T aim And controlling the temperature of the sintering zone and the combustion zone within a normal range in the period, and keeping the current injection parameters of the system to continuously operate.
If the actual final temperature T within a single cycle co > target temperature T aim At the moment, the time length of gas injection in a single period is shortened, so that T co ＝T aim 。
If the actual final temperature T in a single cycle co < target temperature T aim At the moment, the time length of gas injection in a single period is prolonged, so that T co ＝T aim 。
Preferably, in sub-step 6 c), said target temperature T aim The value range of (A) is 600-1000 ℃, preferably 700-850 ℃, and more preferably 740-780 ℃.
Example 1
As shown in figure 1, in the method for auxiliary sintering by periodically and alternately injecting the fuel gas, the fuel gas and the water vapor are periodically and alternately injected to the surface of a sintering mixture, the fuel gas enters the sintering mixture to burn and supply heat, and the water vapor enters the sintering mixture to carry out water-gas reaction with carbon in the solid fuel so as to accelerate the burning of the solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
As shown in fig. 3, the sinter bed on the sintering pallet 1 mainly includes, in order from top to bottom, a sinter bed A1, a combustion zone A2, a drying and preheating zone A3, an over-wetting zone A4, and an original material zone A5 along the thickness direction of the sinter bed.
Example 2
A method for assisting sintering by periodically and intermittently injecting gas and water vapor to the surface of a sintering mixture includes such steps as introducing gas into the sintering mixture for combustion, supplying heat, introducing water vapor into the sintering mixture for water-gas reaction with carbon in solid fuel, and accelerating the combustion of solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
The method for controlling the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed specifically comprises the following steps:
1) Determining the number of cycles for injecting gas, the time length for initially injecting gas in a single cycle, and the time length for initially injecting water vapor in a single cycle.
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
4) And calculating the heat released by the combustion of the injected fuel gas in the sintering material layer in the fuel gas injection time of a single period.
5) And calculating the cooling amount of the mixed gas of the water vapor and the air on the sinter layer in the water vapor blowing time of a single period.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of water vapor and air on the sinter bed, and further realizing the control of the temperature of the regions of the sinter band A1 and the combustion band A2 in the sinter bed.
Example 3
A method for assisting sintering by periodically and intermittently injecting gas and water vapor to the surface of a sintering mixture includes such steps as introducing gas into the sintering mixture for combustion, supplying heat, introducing water vapor into the sintering mixture for water-gas reaction with carbon in solid fuel, and accelerating the combustion of solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
As shown in fig. 2, the implementation of controlling the temperature of the sintering ore zone A1 and the combustion zone A2 in the sinter layer specifically includes the following steps:
1) Determining the number of cycles for injecting gas, the time length for initially injecting gas in a single cycle, and the time length for initially injecting water vapor in a single cycle.
Step 1) comprises the following substeps:
1a) Calculating the operation time t of the sintering trolley in the gas injection section according to the length L of the gas injection section on the sintering machine and the operation speed v of the sintering trolley, namely the total time t for injecting gas and water vapor to the sintering mixture in the sintering trolley is as follows:
1b) Setting the cycle number of gas injection for the sintering mixture in the sintering trolley as N and the time length of initial gas injection in a single cycle as delta t 1 Whereby the time period deltat for the initial injection of water vapor in a single cycle 2 Comprises the following steps:
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of gas to be injected into the sintering mixture in the sintering trolley is as follows:
in the formula: g 1 The total amount of gas to be injected for sintering the mixture in the sintering pallet. And m is the mass of the sintering mixture in the corresponding area of the gas injection section. Q Supplement device The heat quantity needs to be supplemented for the sintering mixture of unit mass after the solid fuel proportion is reduced integrally. H is the heat value of the fuel gas.
The calculation of the injection amount of the fuel gas in unit time specifically comprises the following steps:
in the formula: s. the 1 Is the amount of gas injected per unit time.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
In step 3), the total amount of steam to be injected into the sintering mixture in the sintering trolley is as follows:
G 2 ＝m×R carbon (C) ×γ…………(5)。
In the formula: g 2 The total amount of water vapor required to be blown for sintering the mixture in the sintering pallet. And m is the mass of the sintering mixture in the corresponding area of the gas injection section. R Carbon (C) Is the proportion of solid carbon fuel in the sinter mix. Gamma is the proportional coefficient of water vapor/solid carbon fuel, and the value of gamma is 4.2m 3 /kg。
The calculation of the injection amount of the water vapor in unit time specifically comprises the following steps:
in the formula: s 2 The amount of steam injected per unit time is shown.
4) In the gas injection time of a single period, calculating the heat released by the injected gas in the sintering bed by combustion, specifically comprising the following steps:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
5) In the single period of water vapor injection time, the cooling capacity of the mixed gas of the water vapor and the air to the sinter bed is calculated, and the method specifically comprises the following steps: water vapor injection time at a single cycle 2 The cooling rate of the sinter bed by the mixed gas of water vapor and air is q co Namely, the following steps are provided:
q co ＝h co ·(T burning of -T Steam/air )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 Mixture of water vapor and air in timeThe amount of cooling of the sinter bed. h is co Is the sinter bed cooling coefficient, h co Is 100W/(m) 2 ·℃)。T Burning of The combustion temperature of fuel gas in the material layer. T is Steaming/emptying The temperature of the mixed gas of water vapor and air entering the material layer. A is the specific surface area of the combustion zone in the sintering material layer. Xi is the proportion of the combustion zone in the height direction to the height of the whole material layer, and the value of xi is 0.04.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, and further realizing the control of the temperature of the sinter band and the combustion band area in the sinter bed.
Step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter bed at the corresponding position in a single period:
c p ·ξm·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter layer.
6b) Calculating the actual final temperature T of the sinter bed in a single period co ：
T co ＝T Burning of +ΔT…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the duration of gas injection in a single period, thereby realizing the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer.
Example 4
Example 3 is repeated except that in substep 6 c), the target temperature T is aim The value of (a) is 710 ℃.
Substep 6 c) is specifically:
if the actual final temperature of the sinter bed in a single cycleT co = target temperature T aim And controlling the temperature of the sintering zone and the combustion zone within a normal range in the period, and keeping the current injection parameters of the system to continuously operate.
If the actual final temperature T of the sinter bed in a single cycle co Greater than target temperature T aim At the moment, the time length of gas injection in a single period is shortened, so that T co ＝T aim 。
If the actual final temperature T of the sinter bed in a single cycle co < target temperature T aim At the moment, the time length of gas injection in a single period is prolonged, so that T co ＝T aim 。
Example 5
Example 4 is repeated except that in substep 6 c), the target temperature T aim The value of (A) is 840 ℃.
Example 6
Example 4 is repeated except that in substep 6 c), the target temperature T aim The value of (A) is 760 ℃.
Application example 1
A method for assisting sintering by periodically and intermittently injecting gas and water vapor to the surface of a sintering mixture includes such steps as introducing gas into the sintering mixture for combustion, supplying heat, introducing water vapor into the sintering mixture for water-gas reaction with carbon in solid fuel, and accelerating the combustion of solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
The method for controlling the temperature of the sintering ore zone A1 and the combustion zone A2 in the sintering material layer specifically comprises the following steps:
1) Determining the number of cycles for injecting gas, the time length for initially injecting gas in a single cycle, and the time length for initially injecting water vapor in a single cycle.
Step 1) comprises the following substeps:
1a) Calculating the running time t of the sintering trolley in the gas injection section according to the length L =14.2m of the gas injection section on the sintering machine and the running speed v =2m/min of the sintering trolley, namely the total time t for injecting gas and water vapor to the sintering mixture in the sintering trolley is as follows:
1b) Setting the number of cycles N =10 for injecting gas into the sinter mix in the sintering pallet, and the time length Deltat for initially injecting gas in a single cycle 1 =30s, whereby the time duration Δ t for the initial injection of water vapour in a single cycle 2 Comprises the following steps:
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of gas to be injected into the sintering mixture in the sintering trolley is as follows:
in the formula: g 1 The total amount of gas to be injected for sintering the mixture in the sintering pallet. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. Q Supplement device The heat quantity, Q, is required to be supplemented for integrally reducing the sintered mixture of unit mass after the solid fuel is proportioned Supplement device =12000kJ/kg. H is the heat value of the fuel gas, and H =35588kJ/m 3 。
The calculation of the injection amount of the fuel gas in unit time specifically comprises the following steps:
in the formula: s. the 1 Is the amount of gas injected per unit time.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of steam to be injected into the sintering mixture in the sintering trolley is as follows:
G 2 ＝m×R carbon (C) ×γ＝172800×5％×4.2＝36288m 3 …………(5)。
In the formula: g 2 The total amount of water vapor that needs to be blown for sintering the mix in the sintering pallet. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. R is Carbon (C) The proportion of solid carbon fuel in the sinter mix, R Carbon (C) And =5%. Gamma is the proportionality coefficient of water vapor/solid carbon fuel, and gamma =4.2m 3 /kg。
The calculation of the injection amount of the water vapor in the unit time specifically comprises the following steps:
in the formula: s 2 The amount of water vapor injected per unit time is shown.
4) In the single period of gas injection time, calculating the heat released by the injected gas in the sintering bed by combustion, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
5) In the single period of water vapor injection time, the cooling capacity of the mixed gas of the water vapor and the air to the sinter bed is calculated, and the method specifically comprises the following steps: water vapor injection time at a single cycle 2 The sinter bed is cooled by a mixed gas of water vapor and air at a cooling rate of q co Namely, the following steps are provided:
q co ＝h co ·T burning of -T Steam/air )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 The cooling amount of the mixed gas of the water vapor and the air to the sinter bed in the time. h is co Is the sinter bed cooling coefficient, h co ＝95W/(m 2 ·℃)。T Burning of The combustion temperature, T, of the combustion gas in the sinter bed Burning of ＝1200℃。T Steaming/emptying Is the mixed gas temperature of water vapor and air, T Steam/air =320 ℃. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. A is the specific surface area of a combustion zone in a sintering material layer, and A =0.02326m 2 (iv) g. Xi is the proportion of the combustion zone in the height direction accounting for the height of the whole sinter bed, and xi =0.05.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, and further realizing the control of the temperature of the sinter band A1 and the combustion band A2 in the sinter bed.
Step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter layer at the position close to the gas combustion in a single period:
c p ·ξ·m·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter bed, c p ＝1.1kJ/(kg·℃)。
6b) Calculating the actual final temperature T of the sinter bed at the position close to the gas combustion in a single period co ：
T co ＝T Burning of +ΔT＝1200℃+(-456)℃＝744℃…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the time length of gas injection in a single period, thereby realizing the control of the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed.
Due to the target temperature T aim =744 ℃, obviously with T co ＝T aim In the period, the temperature of the sintering ore zone A1 and the combustion zone A2 is controlled in a normal range, and the system keeps the current injection parameters to continue to operate.
Application example 2
A method for assisting sintering by periodically and intermittently injecting fuel gas comprises the steps of periodically and intermittently injecting fuel gas and water vapor to the surface of a sintering mixture, enabling the fuel gas to enter a sintering material layer for combustion and heat supply, enabling the water vapor to enter the sintering material layer for water gas reaction with carbon in solid fuel, and accelerating the combustion of the solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
The method for controlling the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed specifically comprises the following steps:
1) Determining the number of cycles for injecting gas, the time length for initially injecting gas in a single cycle, and the time length for initially injecting water vapor in a single cycle.
Step 1) comprises the following substeps:
1a) Calculating the running time t of the sintering trolley in the gas injection section according to the length L =14.2m of the gas injection section on the sintering machine and the running speed v =2m/min of the sintering trolley, namely the total time t for injecting gas and water vapor to the sintering mixture in the sintering trolley is as follows:
1b) Setting the number N =10 of the cycles of injecting gas into the sintering mixture in the sintering trolley and the time length delta t of initially injecting gas in a single cycle 1 =30.2s, whereby the time period Δ t for the initial injection of water vapour in a single cycle 2 Comprises the following steps:
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of gas to be injected into the sintering mixture in the sintering trolley is as follows:
in the formula: g 1 The total amount of gas to be blown for sintering the mixture in the sintering pallet. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. Q Supplement device The heat quantity, Q, is required to be supplemented for integrally reducing the sintered mixture of unit mass after the solid fuel is proportioned Supplement device =12000kJ/kg. H is the heat value of the fuel gas, and H =35588kJ/m 3 。
The calculation of the injection amount of the fuel gas in unit time specifically comprises the following steps:
in the formula: s. the 1 Is the amount of gas injected per unit time.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of steam to be injected into the sintering mixture in the sintering trolley is as follows:
G 2 ＝m×R carbon (C) ×γ＝172800×5％×4.2＝36288m 3 …………(5)。
In the formula: g 2 The total amount of water vapor that needs to be blown for sintering the mix in the sintering pallet.m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. R is Carbon (C) The proportion of solid carbon fuel in the sinter mix, R Carbon (C) And =5%. Gamma is the proportionality coefficient of water vapor/solid carbon fuel, gamma =4.2m 3 /kg。
The calculation of the injection amount of the water vapor in unit time specifically comprises the following steps:
in the formula: s. the 2 The amount of steam injected per unit time is shown.
4) In the single period of gas injection time, calculating the heat released by the injected gas in the sintering bed by combustion, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
5) In the single-period steam injection time, calculating the cooling capacity of the mixed gas of the steam and the air on the sinter bed, specifically: water vapor injection time at a single cycle 2 The sinter bed is cooled by a mixed gas of water vapor and air at a cooling rate of q co Namely, the following steps are provided:
q co ＝h co ·T burning of -T Steaming/emptying )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 And cooling the sinter layer by the mixed gas of the water vapor and the air in the time. h is co Is the sinter bed cooling coefficient, h co ＝95W/(m 2 ·℃)。T Burning of For the combustion temperature of the gas in the sinter bed，T Burning of ＝1200℃。T Steam/air Is the mixed gas temperature of water vapor and air, T Steaming/emptying =320 ℃. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. A is the specific surface area of a combustion zone in a sintering material layer, and A =0.02326m 2 (ii) in terms of/g. Xi is the proportion of the combustion zone in the height direction accounting for the height of the whole sinter bed, and xi =0.05.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of water vapor and air on the sinter bed, and further realizing the control of the temperature of the regions of the sinter band A1 and the combustion band A2 in the sinter bed.
Step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter bed at the position close to the gas combustion in a single period:
c p ·ξ·m·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter bed, c p ＝1.1kJ/(kg·℃)。
6b) Calculating the actual final temperature T of the sinter layer at the position close to the gas combustion in a single period co ：
T co ＝T Burning of +ΔT＝1200℃+(-102)℃＝1098℃…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the duration of gas injection in a single period, thereby realizing the control of the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed.
Due to the target temperature T aim =744 ℃ obviously having T co ＞T aim The higher temperature of the sintering zone and the combustion zone area in the injection period indicates that the interstitial time sintering of the injected water vapor is possibleThe gas in the material layer is not flamed out, so that the condition that the red layer is too thick to influence the air permeability of the material layer and cause the negative pressure rise of air draft occurs, the time length of the gas injection in a single period is shortened, and the T-shaped gas injection device is enabled to be T-shaped co ＝T aim And further controlling the temperature of the sintering ore zone and the combustion zone to return to the normal range.
Application example 3
A method for assisting sintering by periodically and intermittently injecting fuel gas comprises the steps of periodically and intermittently injecting fuel gas and water vapor to the surface of a sintering mixture, enabling the fuel gas to enter a sintering material layer for combustion and heat supply, enabling the water vapor to enter the sintering material layer for water gas reaction with carbon in solid fuel, and accelerating the combustion of the solid fuel. In the process of gas injection, the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed is controlled by adjusting the time length of gas injection in a single period.
The method for controlling the temperature of the sintering ore zone A1 and the combustion zone A2 in the sintering material layer specifically comprises the following steps:
1) Determining the number of cycles for injecting gas, the time length for initially injecting gas in a single cycle, and the time length for initially injecting water vapor in a single cycle.
Step 1) comprises the following substeps:
1a) Calculating the operation time t of the sintering pallet in the gas injection section according to the length L =14.2m of the gas injection section on the sintering machine and the operation speed v =2m/min of the sintering pallet, namely the total time t for injecting gas and water vapor to the sintering mixture in the sintering pallet is as follows:
1b) Setting the number N =10 of the cycles of injecting gas into the sintering mixture in the sintering trolley and the time length delta t of initially injecting gas in a single cycle 1 =29.8s, whereby the time period Δ t for the initial injection of water vapour in a single cycle 2 Comprises the following steps:
2) And calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley.
In the step 2), the total amount of gas to be injected into the sintering mixture in the sintering trolley is as follows:
in the formula: g 1 The total amount of gas to be blown for sintering the mixture in the sintering pallet. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. Q Supplement device The heat quantity, Q, of the sintered mixture of unit mass needs to be supplemented after the solid fuel proportion is reduced integrally Supplement device =12000kJ/kg. H is the heat value of the fuel gas, and H =35588kJ/m 3 。
The calculation of the injection amount of the fuel gas in unit time specifically comprises the following steps:
in the formula: s 1 Is the amount of gas injected per unit time.
3) And calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley.
In step 2), the total amount of steam to be injected into the sintering mixture in the sintering trolley is as follows:
G 2 ＝m×R carbon (C) ×γ＝172800×5％×4.2＝36288m 3 …………(5)。
In the formula: g 2 The total amount of water vapor required to be blown for sintering the mixture in the sintering pallet. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. R Carbon (C) The proportion of solid carbon fuel in the sinter mix, R Carbon (C) And =5%. Gamma is the proportionality coefficient of water vapor/solid carbon fuel,γ＝4.2m 3 /kg。
the calculation of the injection amount of the water vapor in the unit time specifically comprises the following steps:
in the formula: s 2 The amount of water vapor injected per unit time is shown.
4) In the single period of gas injection time, calculating the heat released by the injected gas in the sintering bed by combustion, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
5) In the single period of water vapor injection time, the cooling capacity of the mixed gas of the water vapor and the air to the sinter bed is calculated, and the method specifically comprises the following steps: water vapor injection time at a single cycle 2 The sinter bed is cooled by a mixed gas of water vapor and air at a cooling rate of q co Namely, the following steps are provided:
q co ＝h co ·T burning of -T Steaming/emptying )·ξ·m·A…………(8)。
In the formula: q co Is Δ t 2 And cooling the sinter layer by the mixed gas of the water vapor and the air in the time. h is co Is the sinter bed cooling coefficient, h co ＝95W/(m 2 ·℃)。T Burning of The combustion temperature, T, of the combustion gas in the sinter bed Burning of ＝1200℃。T Steaming/emptying Is the mixed gas temperature of water vapor and air, T Steaming/emptying =320 ℃. m is the mass of the sintering mixture in the corresponding area of the gas injection section, and m =172800kg. A is burnSpecific surface area of combustion zone in caking layer, A =0.02326m 2 (ii) in terms of/g. Xi is the proportion of the height of the combustion zone in the height direction in the whole sinter layer, and xi =0.05.
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, and further realizing the control of the temperature of the sinter band A1 and the combustion band A2 in the sinter bed.
Step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of the sinter layer at the position close to the gas combustion in a single period:
c p ·ξ·m·ΔT＝Q in -Q co …………(10)。
namely have
In the formula: c. C p Is the average specific heat capacity of the sinter bed, c p ＝1.1kJ/(kg·℃)。
6b) Calculating the actual final temperature T of the sinter bed at the position close to the gas combustion in a single period co ：
T co ＝T Burning of +ΔT＝1200℃+(-809)℃＝391℃…………(12)。
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the time length of gas injection in a single period, thereby realizing the control of the temperature of the sintered ore zone A1 and the combustion zone A2 in the sinter bed.
Due to the target temperature T aim =744 ℃, i.e. having T co ＜T aim The lower temperature of the sintering zone and the combustion zone area in the injection period possibly influences the normal operation of sintering and the quality of sintering ore, and at the moment, the duration of gas injection in a single period is prolonged, so that T is co ＝T aim And further controlling the temperature of the sintering ore zone and the combustion zone to return to the normal range.
Comparative example 1
A method for assisting sintering by continuously blowing gas is characterized in that gas is continuously blown to the charge level of a sintering mixture, and the gas enters a sintering charge layer to burn for supplying heat to assist sintering. Wherein, aiming at the sintering mixture in the corresponding area of the gas injection section, the total amount G of the continuously injected gas 0 ＝58266m 3 Here, the total amount of gas G continuously blown 0 Total amount of gas G injected periodically with respect to application example 1 1 And are equal. According to the length L of a gas injection section on a sintering machine 0 =14.2m, running speed v of sintering pallet 0 =2m/min, calculating the total time t for blowing gas into the sintering mixture in the sintering trolley 0 ＝L 0 /v 0 =426s, total duration t of gas injection into sinter mix in sinter car here 0 The total time period t for blowing the gas and the water vapor to the sinter mix in the sintering pallet in application example 1 was the same. In comparative example 1, the gas injection flow rate, that is, the injection amount S of gas per unit time 0 ＝G 0 /t 0 ＝136.78m 3 /s。
The temperature of the sinter layer during sintering was measured, and the temperature change curves of the sinter layer of application example 1 and comparative example 1 were plotted, as shown in fig. 7. The relevant test data for application example 1 and comparative example 1 are recorded as follows:
the invention changes the existing method for continuously injecting fuel gas, and adopts periodic interval injection measures to inject fuel gas and water vapor into the sintering material layer at intervals and orderly. As can be seen from the above table in conjunction with FIG. 7, the present invention can achieve the maximum gas injection amount to ensure a large proportion of solid fuel substitution and CO substitution while maintaining the original gas supply amount 2 On the premise of emission reduction, the temperature change curve of the sintered ore zone and the area near the combustion zone is improved, the thickness of a red layer is weakened, and proper material bed air permeability and normal air draft negative pressure are ensured, so that the yield and the quality of the sintered ore are improved. At the same timeThe sprayed water vapor and carbon generate water gas reaction, so that the ignition and combustion of the solid fuel in a combustion zone and an unburned material layer are accelerated, the downward moving speed of a front of the combustion zone is accelerated, and the problems of greatly improving the gas injection amount, reducing the sintering speed after the solid fuel and reducing the sintering utilization coefficient are solved. The water gas reaction changes part of the solid fuel combustion reaction path, so that carbon combustion is more complete, and the CO concentration in the flue gas is reduced.
Claims (10)
1. A method for auxiliary sintering by interval injection of fuel gas and water vapor is characterized in that: injecting gas and water vapor to the surface of the sintering mixture at periodic intervals, wherein the gas enters the sintering mixture layer for combustion and heat supply, and the water vapor enters the sintering mixture layer for water gas reaction with carbon in the solid fuel to accelerate the combustion of the solid fuel; in the process of gas injection, the temperature of the sintering ore zone and the combustion zone area in the sintering material layer is controlled by adjusting the time length of gas injection in a single period.
2. The method of claim 1, wherein: the method for controlling the temperature of the sintering ore zone and the combustion zone area in the sintering material layer specifically comprises the following steps:
1) Determining the cycle number of gas injection, the time length of initial gas injection in a single cycle and the time length of initial steam injection in a single cycle;
2) Calculating the injection amount of the fuel gas in unit time according to the total amount of the fuel gas to be injected into the sintering mixture in the sintering trolley;
3) Calculating the injection amount of the water vapor in unit time according to the total amount of the water vapor required to be injected into the sintering mixture in the sintering trolley;
4) Calculating the heat released by the combustion of the injected fuel gas in the sintering bed within the fuel gas injection time of a single period;
5) In the steam injection time of a single period, calculating the cooling capacity of the mixed gas of the steam and the air to the sinter bed;
6) And judging the temperature change condition of the sinter bed in a single period according to the heat released by the combustion of the injected gas and the cooling capacity of the mixed gas of the water vapor and the air on the sinter bed, thereby realizing the control of the temperature of the sinter band and the combustion band area in the sinter bed.
3. The method of claim 2, wherein: step 1) comprises the following substeps:
1a) Calculating the operation time t of the sintering pallet in the gas injection section according to the length L of the gas injection section on the sintering machine and the operation speed v of the sintering pallet, namely the total duration t of injecting gas and water vapor to the sintering mixture in the sintering pallet is as follows:
1b) Setting the number of cycles for injecting gas into the sintering mixture in the sintering trolley to be N and the time length for initially injecting gas in a single cycle to be delta t 1 Whereby the time period deltat for the initial injection of water vapor in a single cycle 2 Comprises the following steps:
4. a method according to claim 2 or 3, characterized in that: in the step 2), the total amount of gas to be injected into the sintering mixture in the sintering trolley is as follows:
in the formula: g 1 The total amount of gas to be injected for sintering the mixture in the sintering trolley; m is the quality of the sintering mixture in the corresponding area of the gas injection section; q Supplement device Heat is required to be supplemented for integrally reducing the sintering mixture of unit mass after the solid fuel is proportioned; h is the heat value of the fuel gas;
preferably, in step 2), the calculating the injection amount of the fuel gas per unit time specifically includes:
in the formula: s. the 1 Is the amount of gas injected per unit time.
5. The method according to any one of claims 2-4, wherein: in step 3), the total amount of steam to be injected into the sintering mixture in the sintering trolley is as follows:
G 2 ＝m×R carbon (C) ×γ............(5)；
In the formula: g 2 The total amount of steam required to be blown for sintering the mixture in the sintering trolley; m is the quality of the sintering mixture in the corresponding area of the gas injection section; r Carbon (C) The proportion of the solid carbon fuel in the sintering mixture; gamma is the proportional coefficient of water vapor/solid carbon fuel, and the value range of gamma is 3.6-5.4 m 3 /kg；
Preferably, in step 3), the calculating the blowing amount of the water vapor per unit time specifically includes:
in the formula: s. the 2 The amount of steam injected per unit time is shown.
6. The method according to claim 4 or 5, characterized in that: in step 4), calculating the heat released by the combustion of the injected fuel gas in the sintering bed within the single period of fuel gas injection time, specifically:
in the formula: q in Is Δ t 1 The heat released by the combustion of the injected gas in the time.
7. The method according to any one of claims 3-6, wherein: in step 5), the cooling amount of the mixed gas of the water vapor and the air to the sinter layer is calculated within the water vapor injection time of a single period, specifically: water vapor injection time at a single cycle 2 The sinter bed is cooled by a mixed gas of water vapor and air at a cooling rate of q co Namely, the following steps are provided:
q co ＝h co ·(T burning of -T Steaming/emptying )·ξ·m·A............(8)；
In the formula: q co Is Δ t 2 The cooling capacity of the mixed gas of the water vapor and the air to the sinter bed in time; h is co Is the sinter bed cooling coefficient, h co The value range of (A) is 90-110W/(m) 2 ·℃)；T Burning of The combustion temperature of fuel gas in the sintering material layer; t is Steaming/emptying The temperature of the mixed gas of water vapor and air entering the material layer; m is the quality of the sintering mixture in the corresponding area of the gas injection section; a is the specific surface area of a combustion zone in a sintering charge layer; xi is the proportion of the height of the combustion zone in the height direction of the whole sintering material layer, and the value range of xi is 0-1, preferably 0.01-0.1.
8. The method of claim 7, wherein: step 6) comprises the following substeps:
6a) According to the heat balance principle, calculating the temperature change value delta T of a sinter bed at the gas combustion position in a single period:
c p .ξ·m.ΔT＝Q in -Q co ............(10)；
namely have
In the formula: c. C p The average specific heat capacity of the sinter bed;
6b) Calculating the actual final temperature T of the sinter bed at the corresponding position in a single period co ：
T co ＝T Burning of +ΔT............(12)；
6c) Comparing the actual final temperature T of the sinter bed in a single cycle co With a target temperature T aim And further adjusting the time length of gas injection in a single period, thereby realizing the control of the temperature of the sintering ore zone and the combustion zone area in the sintering material layer.
9. The method of claim 8, wherein: substep 6 c) is specifically:
if the actual final temperature T of the sinter bed in a single cycle co = target temperature T aim The temperature of the sintering zone and the combustion zone is controlled within a normal range in the period, and the system keeps the current injection parameters to continue to operate;
if the actual final temperature T of the sinter bed in a single cycle co Greater than target temperature T aim At the moment, the time length of gas injection in a single period is shortened, so that T co ＝T aim ；
If the actual final temperature T of the sinter bed in a single cycle co < target temperature T aim At the moment, the time length of gas injection in a single period is prolonged, so that T co ＝T aim 。
10. The method according to claim 8 or 9, characterized in that: in sub-step 6 c), the target temperature T aim The value range of (A) is 600-1000 ℃, preferably 700-850 ℃, and more preferably 740-780 ℃.
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