CN114662767A - Low-carbon blast furnace smelting cost control method and system - Google Patents

Low-carbon blast furnace smelting cost control method and system Download PDF

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CN114662767A
CN114662767A CN202210315374.7A CN202210315374A CN114662767A CN 114662767 A CN114662767 A CN 114662767A CN 202210315374 A CN202210315374 A CN 202210315374A CN 114662767 A CN114662767 A CN 114662767A
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许俊
肖学文
王刚
赵运建
牛群
贺坤
李牧明
赖菲菲
侯世锋
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CISDI Engineering Co Ltd
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Abstract

The invention provides a low-carbon blast furnace smelting cost control method and a low-carbon blast furnace smelting cost control system, which are used for obtaining the fuel type and the cost unit price of each fuel during low-carbon blast furnace smelting; establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel; then obtaining constraint conditions for low-carbon blast furnace smelting and fuel proportioning ranges meeting all the constraint conditions; and then calculating the minimum cost value of the smelting cost objective function when smelting a preset amount of steel in the fuel proportioning range, and outputting the fuel proportioning at the minimum cost value. According to the method, the blast furnace smelting is carried out according to the fuel ratio corresponding to the minimum cost value, so that the influence of the fuel cost on the low-carbon blast furnace smelting can be linked, and the blast furnace can be ensured to stably and efficiently operate on the basis of high efficiency and low carbon, so that a smelting scheme with the minimum cost is obtained; and after the fuel type and/or the unit price of the fuel are changed, the smelting scheme with the minimum cost can be calculated according to the changed conditions.

Description

Low-carbon blast furnace smelting cost control method and system
Technical Field
The invention relates to the technical field of blast furnace smelting, in particular to a low-carbon blast furnace smelting cost control method and system.
Background
The low-carbon blast furnace reduces carbon emission, and meanwhile, low-cost smelting is also a pursued target. The main cost of blast furnace smelting is ore and fuel, the fuel is an important factor influencing the cost, and because the price of raw materials fluctuates along with time, the scheme of low-cost iron making is continuously changed, therefore, a set of suitable scheme should be provided for realizing low-cost blast furnace smelting, and the scheme of blast furnace smelting can be optimized according to the change of the conditions and the price of the raw materials at any time.
Disclosure of Invention
In view of the above disadvantages of the prior art, the present invention provides a method and a system for controlling smelting cost of a low-carbon blast furnace, which are used for solving the problem that the cost cannot be optimized during low-carbon blast furnace smelting in the prior art.
In order to achieve the above objects and other related objects, the present invention provides a low-carbon blast furnace smelting cost control method, comprising the steps of:
obtaining the fuel category and the cost unit price of each fuel when the low-carbon blast furnace smelting is carried out;
establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel;
obtaining constraint conditions when low-carbon blast furnace smelting is carried out and fuel proportioning ranges when all the constraint conditions are met;
calculating the cost value of the smelting cost objective function which meets smelting constraint conditions in the fuel proportioning range, and outputting the fuel proportioning of the smelting cost objective function at the minimum cost value;
wherein, the constraint conditions for smelting the low-carbon blast furnace comprise at least one of the following conditions: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas.
Optionally, the method further comprises judging whether the material balance is met when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected, and the following steps are carried out:
obtaining raw material components and blast furnace smelting technological parameters during low-carbon blast furnace smelting, wherein the blast furnace smelting technological parameters at least comprise: the element distribution rate, the slag alkalinity, the initial direct reduction degree of iron and the initial hydrogen-rich gas injection amount;
calculating the amount of iron ore according to the element distribution ratio and the raw material components, and calculating the initial amount of the flux according to the alkalinity of the slag;
calculating the amount of slag and the composition of the slag according to the amount of the iron ore, the initial amount of the molten metal, a preset initial coke ratio and a preset initial coal ratio;
checking whether the basic oxides in the slag meet the desulfurization standard based on the calculated amount of the slag and the slag components; if the amount of the basic oxides in the slag does not meet the desulfurization standard, adjusting the initial melt amount and then recalculating new slag amount and slag components until the basic oxides in the slag meet the desulfurization standard; if so, calculating the utilization rate of the gas based on the gas quantity, the gas components and the direct reduction degree of the initial iron in the tuyere raceway;
judging whether the coal gas utilization rate is less than or equal to a preset thermodynamic limit value or not; if the current time is less than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the material balance; if the quantity of the coke is larger than the preset value, judging that the low-carbon blast furnace at the current moment does not meet the material balance, adjusting the preset initial coke ratio, the preset initial coal ratio, the initial hydrogen-rich gas injection quantity and the initial iron direct reduction degree, and judging the material balance of the low-carbon blast furnace again after the adjustment is finished until the material balance is met.
Optionally, the step of calculating the gas utilization rate based on the gas amount, the gas components and the initial iron direct reduction degree of the tuyere raceway comprises:
after the basic oxides in the slag meet the desulfurization standard, calculating the components of the molten iron according to the raw material components, the amount of the iron ore, the amount of the molten metal meeting the desulfurization standard, a preset initial coal ratio, a preset initial coke ratio and the element distribution ratio;
judging whether the molten iron components calculated by the kernel meet preset requirements or not; if the new molten iron composition does not meet the preset requirements, adjusting the preset initial coal ratio, the preset initial coke ratio and the initial hydrogen-rich gas injection amount, and recalculating the molten iron composition after the adjustment is completed; if so, calculating the air volume according to carbon brought by the fuel, carburization of the molten iron and carbon consumption of reduction of elements in the molten iron;
and calculating the gas quantity and the gas component of the tuyere raceway according to the calculated air quantity, the raw material components, the coke ratio when the molten iron component accounting is met, and the coal ratio when the molten iron component accounting is met, and calculating the gas utilization rate based on the gas quantity and the gas component of the tuyere raceway and the direct reduction of the initial iron.
Optionally, the method further comprises judging whether heat balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected, and the following steps are performed:
when the low-carbon blast furnace meets the material balance, acquiring a coke ratio meeting the material balance, a coal ratio meeting the material balance and a hydrogen-rich gas injection amount meeting the material balance, calculating a coke heat value according to the coke ratio meeting the material balance and a corresponding calorific value, calculating a coal specific heat value according to the coal ratio meeting the material balance and the corresponding calorific value, and calculating a hydrogen-rich gas heat value according to the hydrogen-rich gas meeting the material balance and the corresponding calorific value;
obtaining a heat value brought when the air volume enters the low-carbon blast furnace and a heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace;
adding the coke calorific value, the coal specific heat value, the hydrogen-rich gas calorific value, the calorific value brought by the air volume when entering the low-carbon blast furnace and the calorific value brought by the hydrogen-rich gas when being blown into the low-carbon blast furnace, and taking the addition result as a heat input value;
calculating a difference value between the thermal income value and the thermal expenditure value, and judging whether a result obtained by dividing the difference value by the thermal income value is greater than or equal to a preset ratio or not; if the current time is greater than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the heat balance; if the current heat balance is smaller than the preset heat balance, judging that the low-carbon blast furnace at the current moment does not meet the heat balance, adjusting a preset initial coke ratio, a preset initial coal ratio, an initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the heat balance of the low-carbon blast furnace again;
wherein the thermal payout value comprises at least one of: the decomposition heat of the oxide brought by the ore, the decomposition heat of the oxide brought by the coke, the decomposition heat of the oxide brought by the coal powder, the heat consumed by iron reduction, the heat consumed by silicon reduction, the heat consumed by manganese reduction, the heat consumed by phosphorus reduction, the heat consumed by sulfur reduction, the enthalpy of molten iron, the enthalpy of slag, the enthalpy of coal gas and the heat value of coal gas.
Optionally, the method further includes determining whether the temperature distribution in the furnace during low-carbon blast furnace smelting after hydrogen-rich gas injection satisfies a preset temperature condition for blast furnace smelting, including:
when the low-carbon blast furnace meets the heat balance, calculating the theoretical combustion temperature according to the gas quantity and the gas components in the tuyere raceway;
calculating the material water equivalent and the gas water equivalent of the low-carbon blast furnace, and obtaining the temperature distribution from a zero stock line to a tuyere on the basis of the material water equivalent and the gas water equivalent;
determining the position and width of a reflow zone and the height of a reduction temperature zone according to the furnace temperature and the reflow temperature of the ore in the temperature distribution;
judging whether the position of the reflow zone and the height of the reduction temperature zone are in a preset interval, and if so, judging that the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when low-carbon blast furnace smelting is carried out at the current moment; if the temperature distribution is not in the preset interval, adjusting the blast parameters, the preset initial coke ratio, the preset initial coal ratio and the initial hydrogen-rich gas injection amount, and judging whether the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when the low-carbon blast furnace smelting is carried out again.
Optionally, the method further comprises judging whether the furnace pressure difference during low-carbon blast furnace smelting after hydrogen-rich gas injection meets the blast furnace smelting pressure difference condition, and the method comprises the following steps:
acquiring pre-calculated block belt pressure difference, reflow belt pressure difference and dripping belt pressure difference;
adding the block belt pressure difference, the reflow belt pressure difference and the dripping belt pressure difference, and taking the addition result as the furnace pressure difference during the low-carbon blast furnace smelting at the current moment;
calculating an error value of the pressure difference in the furnace and the pressure difference in the standard furnace at the current moment, and judging whether the error value is greater than a preset error value or not;
if the difference is larger than the preset difference, the furnace pressure difference when the low-carbon blast furnace smelting is carried out at the current moment is judged not to meet the blast furnace smelting pressure difference condition, and the fuel ratio when the block belt pressure difference, the reflow belt pressure difference and the dropping belt pressure difference are calculated is adjusted and calculated again until the error value is smaller than or equal to the preset error value;
and if the pressure difference is smaller than or equal to the preset value, judging that the pressure difference in the furnace meets the condition of the blast furnace smelting pressure difference when the low-carbon blast furnace smelting is carried out at the current moment.
Optionally, the calculating of the block band pressure difference includes:
obtaining average grain size of furnace burden, block belt void ratio, shape coefficient of furnace burden, empty furnace flow rate of furnace gas, density of furnace gas and dynamic viscosity of furnace gas when low-carbon blast furnace smelting is carried out, and calculating block belt pressure loss gradient according to the average grain size of furnace burden, the block belt void ratio, the shape coefficient of furnace burden, the empty furnace flow rate of furnace gas, the density of furnace gas and the dynamic viscosity of furnace gas;
acquiring a predetermined position of a reflow belt, and determining the height of a block belt according to the position of the reflow belt;
and calculating the corresponding block belt pressure difference based on the height of the block belt and the pressure loss gradient of the block belt.
Optionally, the calculation process of the reflow belt pressure difference includes:
obtaining the void ratio of a reflow zone, the density of a ore layer before reflow, the density of the ore layer during reflow, the thickness of an ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow during low-carbon blast furnace smelting, and calculating the pressure loss gradient of the reflow zone according to the void ratio of the reflow zone, the density of the ore layer before reflow, the density of the ore layer during reflow, the thickness of the ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow;
and acquiring the width of the reflow belt, and calculating the corresponding reflow belt pressure difference based on the width of the reflow belt and the pressure loss gradient of the reflow belt.
Optionally, the calculation process of the drop zone pressure difference comprises:
obtaining slag iron retention rate, a harmonic mean of average coke particle size and average slag iron droplet diameter and a dropping belt coke void ratio in a coke layer during low-carbon blast furnace smelting, and calculating a dropping belt pressure loss gradient according to the slag iron retention rate, the harmonic mean of the average coke particle size and the average slag iron droplet diameter and the dropping belt coke void ratio in the coke layer;
and acquiring the height of the dripping zone, and calculating the pressure difference of the dripping zone based on the height of the dripping zone and the pressure loss gradient of the dripping zone.
The invention also provides a low-carbon blast furnace smelting cost control system, which comprises a client subsystem and a background processing subsystem;
the client subsystem is used for inputting the fuel type for low-carbon blast furnace smelting, the cost unit price of each fuel, the constraint condition for low-carbon blast furnace smelting and the fuel proportion for displaying the smelting cost objective function at the minimum cost value;
the background processing subsystem is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel, acquiring a fuel proportioning range meeting all constraint conditions, and calculating a cost value of the smelting cost objective function meeting the smelting constraint conditions in the fuel proportioning range;
wherein, the constraint conditions for smelting the low-carbon blast furnace comprise at least one of the following conditions: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas.
Optionally, the background processing subsystem includes:
the material balance module is used for judging whether the material balance is met or not when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected;
the heat balance module is used for judging whether the heat balance is met or not when the low-carbon blast furnace is smelted after hydrogen-rich gas is injected after the low-carbon blast furnace meets the material balance;
the furnace internal temperature module is used for judging whether the temperature distribution in the furnace during low-carbon blast furnace smelting after hydrogen-rich gas injection meets the preset temperature condition for blast furnace smelting after the low-carbon blast furnace meets the heat balance;
the furnace internal pressure difference module is used for judging whether the furnace internal pressure difference meets the blast furnace smelting pressure difference condition when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected after the temperature distribution in the furnace meets the preset blast furnace smelting temperature condition;
the objective function module is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel;
and the cost calculation module is used for acquiring a fuel proportioning range meeting the fuel supply quantity and calculating the cost value of the smelting cost objective function meeting the smelting constraint condition in the fuel proportioning range.
Optionally, the client subsystem includes:
the input module is used for inputting the fuel type when the low-carbon blast furnace smelting is carried out, the cost unit price of each fuel and the constraint condition when the low-carbon blast furnace smelting is carried out;
and the display module is used for displaying the minimum cost value of the smelting cost objective function and displaying the fuel ratio corresponding to the smelting cost objective function at the minimum cost value.
As described above, the invention provides a method and a system for controlling the smelting cost of a low-carbon blast furnace, which have the following beneficial effects: the method comprises the steps of obtaining the fuel category and the cost unit price of each fuel when low-carbon blast furnace smelting is carried out; establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel; simultaneously obtaining constraint conditions for low-carbon blast furnace smelting and fuel proportioning ranges meeting all the constraint conditions; and then calculating the minimum cost value of the smelting cost objective function when a preset amount of steel is smelted in the fuel proportioning range, and outputting the fuel proportioning of the smelting cost objective function at the minimum cost value. Therefore, a smelting cost objective function for controlling the smelting cost of the blast furnace is established according to the type of the fuel and the unit price of the fuel, then the minimum value of the smelting cost objective function is determined by combining constraint conditions during smelting of the low-carbon blast furnace, and when a preset amount of steel is smelted, the fuel ratio corresponding to the minimum value of the smelting cost objective function is the optimal smelting cost scheme; the blast furnace smelting is carried out according to the fuel proportion corresponding to the minimum cost value, so that the influence of the fuel cost on the low-carbon blast furnace smelting can be linked, and the blast furnace can be ensured to stably and efficiently operate on the basis of high efficiency and low carbon, thereby obtaining an optimal blast furnace fuel scheme for low-cost smelting. Meanwhile, when blast furnace smelting is carried out, even if the type of fuel and/or the unit price of the fuel are/is changed, the smelting scheme with the minimum cost is finally obtained, so that the method can realize the smelting with the minimum cost of each low-carbon blast furnace under respective constraint conditions at any time according to market fluctuation.
Drawings
FIG. 1 is a schematic flow chart of a low-carbon blast furnace smelting cost control method provided in an embodiment;
FIG. 2 is a schematic flow chart of a low-carbon blast furnace smelting cost control method according to another embodiment;
FIG. 3 is a schematic diagram of a hardware structure of the low-carbon blast furnace smelting cost control system according to an embodiment.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Example 1:
referring to fig. 1, the present embodiment provides a method for controlling smelting cost of a low-carbon blast furnace, including the following steps:
and S10, obtaining the fuel type and the cost unit price of each fuel when the low-carbon blast furnace smelting is carried out. As an example, the fuel type and the cost unit price of each fuel in the present embodiment may be directly input by an external person, or may be obtained by a server or a processor from a database in which the fuel type and the cost unit price are stored in advance. In addition, the fuel type in this embodiment may be determined according to different blast furnaces, for example, in a blast furnace of a certain iron works, the fuel type may be coke, coal powder, and coke oven gas. The coke oven gas (also called coke oven gas) is a combustible gas produced when coke and tar products are produced after high-temperature dry distillation in a coke oven by using several kinds of bituminous coal to prepare coking coal.
And S20, establishing a smelting cost objective function according to the fuel types and the cost unit price of each fuel. By way of example, in a blast furnace of an iron works, the fuel types may be coke, coal dust and coke oven gas, where the price of coke is 2.500 yuan/kg, the price of coal dust is 0.9 yuan/kg and the coke oven gas is 0.8 yuan/cubic meter, and the objective smelting cost function for smelting a single ton of steel may be: y 2.500 Xj +0.900 Xm +0.8 Xg; in the formula, Xj represents a coke ratio, Xm represents a coal ratio, and Xg represents coke oven gas.
S30, obtaining constraint conditions for low-carbon blast furnace smelting and fuel proportioning ranges meeting all the constraint conditions; the constraint conditions for low-carbon blast furnace smelting include but are not limited to: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas.
S40, calculating the cost value of the smelting cost objective function when the smelting cost objective function is in the fuel ratio range, smelting a preset amount of steel and meeting smelting constraint conditions, and outputting the fuel ratio of the smelting cost objective function at the minimum cost value. By way of example, the fuel ratio in the present embodiment may be determined according to different blast furnaces, for example, for a certain blast furnace, the fuel ratio may be a coke ratio, a coal ratio, and a coke oven gas. Wherein, the coke ratio refers to the ton of coke consumed by the blast furnace for smelting one ton of qualified steel, and the coal ratio refers to the coal dust consumed by the blast furnace for smelting one ton of qualified steel. The preset quantity in this embodiment may be set according to an actual situation, for example, the preset quantity may be set to be a single ton, that is, a minimum cost value of the smelting cost objective function when smelting a single ton of steel in the fuel proportioning range is calculated.
According to the above description, step S30 of this embodiment further includes determining whether the material balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected after the constraint condition of the material balance is obtained. Specifically, raw material components and blast furnace smelting process parameters during low-carbon blast furnace smelting are obtained, and the blast furnace smelting process parameters at least comprise: the element distribution rate, the slag alkalinity, the initial direct reduction degree of iron and the initial hydrogen-rich gas injection amount; calculating the amount of iron ore according to the element distribution ratio and the raw material components, and calculating the initial amount of the flux according to the alkalinity of the slag; calculating the amount of slag and the composition of the slag according to the amount of the iron ore, the initial amount of the molten metal, a preset initial coke ratio and a preset initial coal ratio; checking whether the basic oxides in the slag meet the desulfurization standard based on the calculated amount of the slag and the slag components; if the amount of the basic oxides in the slag does not meet the desulfurization standard, adjusting the initial melt amount and then recalculating new slag amount and slag components until the basic oxides in the slag meet the desulfurization standard; if so, calculating the components of the molten iron according to the components of the raw materials, the quantity of the iron ores, the quantity of the molten metal meeting the desulfurization standard, a preset initial coal ratio, a preset initial coke ratio and the element distribution rate; judging whether the molten iron components calculated by the kernel meet preset requirements or not; if the new molten iron composition does not meet the preset requirements, adjusting the preset initial coal ratio, the preset initial coke ratio and the initial hydrogen-rich gas injection amount, and recalculating the molten iron composition after the adjustment is completed; if so, calculating the air volume according to carbon brought by the fuel, carburization of the molten iron and carbon consumption of reduction of elements in the molten iron; calculating the gas quantity and the gas component of the tuyere raceway according to the calculated air quantity, the raw material components, the coke ratio when the molten iron component accounting is met, and the coal ratio when the molten iron component accounting is met, calculating the top gas component based on the gas quantity and the gas component of the tuyere raceway and the direct reduction of iron, and calculating the gas utilization rate according to the top gas component; judging whether the coal gas utilization rate is less than or equal to a preset thermodynamic limit value or not; if the current time is less than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the material balance; if the initial coke ratio is larger than the initial coal ratio, judging that the low-carbon blast furnace at the current moment does not meet the material balance, adjusting the preset initial coke ratio, the preset initial coal ratio, the initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the material balance of the low-carbon blast furnace again after the adjustment is finished until the material balance is met. As an example, the preset thermodynamic limit value in the present embodiment may be set according to actual conditions, for example, the preset thermodynamic limit value may be set to 49.5%. In the embodiment, the blast furnace meets the material balance after the hydrogen-rich medium is injected, and the coal gas utilization rate can meet the thermodynamic condition of iron oxide reduction.
According to the above description, the step S30 of the present embodiment further includes determining whether the thermal balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected after the constraint condition of the thermal balance is obtained. Specifically, when the low-carbon blast furnace meets the material balance, acquiring a coke ratio meeting the material balance, a coal ratio meeting the material balance and a hydrogen-rich gas injection amount meeting the material balance, calculating a coke heat value according to the coke ratio meeting the material balance and a corresponding calorific value, calculating a coal specific heat value according to the coal ratio meeting the material balance and the corresponding calorific value, and calculating a hydrogen-rich gas heat value according to the hydrogen-rich gas meeting the material balance and the corresponding calorific value; obtaining a heat value brought when the air volume enters the low-carbon blast furnace and a heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace; adding the coke heat value, the coal specific heat value, the hydrogen-rich gas heat value, the heat value brought when the air volume enters the low-carbon blast furnace and the heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace, and taking the added result as a heat input value; calculating a difference value between the thermal income value and the thermal expenditure value, and judging whether a result obtained by dividing the difference value by the thermal income value is greater than or equal to a preset ratio or not; if the current time is more than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the heat balance; if the current heat balance is smaller than the preset heat balance, judging that the low-carbon blast furnace at the current moment does not meet the heat balance, adjusting a preset initial coke ratio, a preset initial coal ratio, an initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the heat balance of the low-carbon blast furnace again; wherein the thermal payout values include, but are not limited to: the decomposition heat of the oxide brought by the ore, the decomposition heat of the oxide brought by the coke, the decomposition heat of the oxide brought by the coal powder, the heat consumed by iron reduction, the heat consumed by silicon reduction, the heat consumed by manganese reduction, the heat consumed by phosphorus reduction, the heat consumed by sulfur reduction, the enthalpy of molten iron, the enthalpy of slag, the enthalpy of coal gas and the heat value of coal gas. As an example, the preset ratio in the embodiment may be set according to actual conditions, for example, the preset ratio may be set to 5%. According to the embodiment, the blast furnace can meet the heat balance after the hydrogen-rich medium is injected, and the heat balance of the blast furnace can be ensured.
According to the above description, the step S30 of the present embodiment further includes, after obtaining the constraint condition of the temperature distribution in the furnace, determining whether the temperature distribution in the furnace during the low-carbon blast furnace smelting after the hydrogen-rich gas is injected satisfies the preset temperature condition for blast furnace smelting. Specifically, when the low-carbon blast furnace meets the heat balance, the theoretical combustion temperature is calculated according to the gas quantity and the gas components in the tuyere raceway; calculating the material water equivalent and the coal gas water equivalent of the low-carbon blast furnace, and obtaining the temperature distribution from a zero material line to a tuyere based on the material water equivalent and the coal gas water equivalent; determining the position and the width of a reflow zone and the height of a reduction temperature zone according to the furnace temperature and the reflow temperature of the ore in the temperature distribution; judging whether the position of the reflow zone and the height of the reduction temperature zone are in a preset interval, and if so, judging that the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when low-carbon blast furnace smelting is carried out at the current moment; if the temperature distribution is not in the preset interval, adjusting the blast parameters, the preset initial coke ratio, the preset initial coal ratio and the initial hydrogen-rich gas injection amount, and judging whether the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when the low-carbon blast furnace smelting is carried out again. As an example, the preset interval in the present embodiment may be set for each blast furnace. According to the embodiment, after the hydrogen-rich medium is injected, the temperature distribution in the blast furnace meets the preset temperature condition, and the position of the blast furnace reflow zone and the indirect reduction zone can be ensured to be proper. Specifically, a temperature distribution from a zero stock line to a tuyere is obtained based on the material water equivalent and the gas water equivalent, and there are:
Figure BDA0003568848270000081
in the formula, ωs＝mscsRepresenting the equivalent weight of material water;
ωg＝mgcgrepresents the equivalent of gas water;
q represents the volume of the iron material per ton;
kvexpressing the comprehensive heat exchange coefficient of unit furnace burden and coal gas;
z represents the height of the calculation point from the starting point;
v represents the volume of material descending per second;
r represents the radius at the point of initiation of the calculation;
r represents the radius at the end of the calculation;
h represents the height of the furnace body;
tg(Z) represents the gas temperature at Z;
ts(Z) represents the temperature of the material at Z.
According to the above description, step S30 of this embodiment further includes determining whether or not the furnace pressure difference at the time of low-carbon blast furnace smelting after injecting hydrogen-rich gas satisfies the blast furnace smelting pressure difference condition after acquiring the constraint condition of the furnace pressure difference. Specifically, a block belt pressure difference, a reflow belt pressure difference and a dripping belt pressure difference which are calculated in advance are obtained; adding the block belt pressure difference, the reflow belt pressure difference and the dripping belt pressure difference, and taking the addition result as the furnace pressure difference during the low-carbon blast furnace smelting at the current moment; calculating an error value of the pressure difference in the furnace and the pressure difference in the standard furnace at the current moment, and judging whether the error value is greater than a preset error value or not; if the difference is larger than the preset difference, the furnace pressure difference when the low-carbon blast furnace smelting is carried out at the current moment is judged not to meet the blast furnace smelting pressure difference condition, and the fuel ratio when the block belt pressure difference, the reflow belt pressure difference and the dropping belt pressure difference are calculated is adjusted and calculated again until the error value is smaller than or equal to the preset error value; and if the pressure difference is smaller than or equal to the preset value, judging that the pressure difference in the furnace meets the condition of the blast furnace smelting pressure difference when the low-carbon blast furnace smelting is carried out at the current moment. As an example, the standard furnace differential pressure in the embodiment may be the same type of blast furnace differential pressure, and the preset error value may be set according to the actual situation, for example, the preset error value may be set to 10%. According to the embodiment, the pressure difference in the blast furnace after the hydrogen-rich medium is injected meets the smelting pressure difference condition of the blast furnace, so that the blast furnace can be ensured to stably and smoothly move.
According to the above description, the process of calculating the block belt pressure difference includes: obtaining average grain size of furnace burden, block belt void ratio, shape coefficient of furnace burden, empty furnace flow rate of furnace gas, density of furnace gas and dynamic viscosity of furnace gas when low-carbon blast furnace smelting is carried out, and calculating block belt pressure loss gradient according to the average grain size of furnace burden, the block belt void ratio, the shape coefficient of furnace burden, the empty furnace flow rate of furnace gas, the density of furnace gas and the dynamic viscosity of furnace gas; obtaining a predetermined position of a reflow belt, and determining the height of a block belt according to the position of the reflow belt; and calculating the corresponding block belt pressure difference based on the height of the block belt and the pressure loss gradient of the block belt. Specifically, the calculation method of the block belt pressure difference comprises the following steps:
Figure BDA0003568848270000091
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000092
representing a bulk tape pressure loss gradient;
Figure BDA0003568848270000101
expressed as the height of the block belt;
dprepresents the average particle size of the charge;
ε represents the blocky band void fraction;
Figure BDA0003568848270000107
representing a charge shape factor;
ugrepresenting the empty furnace flow rate of the coal gas;
ρgrepresents the density of the gas;
mu represents the kinetic viscosity of the gas.
According to the above record, the calculation process of the reflow zone pressure difference comprises: obtaining the void ratio of a reflow zone, the density of a ore layer before reflow, the density of the ore layer during reflow, the thickness of an ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow during low-carbon blast furnace smelting, and calculating the pressure loss gradient of the reflow zone according to the void ratio of the reflow zone, the density of the ore layer before reflow, the density of the ore layer during reflow, the thickness of the ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow; and acquiring the width of the reflow belt, and calculating the corresponding reflow belt pressure difference based on the width of the reflow belt and the pressure loss gradient of the reflow belt. Specifically, the calculation method of the reflow belt pressure difference comprises the following steps:
Figure BDA0003568848270000102
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000103
representing a pressure loss gradient of the reflow belt;
Figure BDA0003568848270000104
expressed as the width of the reflow ribbon;
εbthe void ratio of the reflow band is shown,
Figure BDA0003568848270000105
ρprepresenting the density of the ore layer before the reflow;
ρbthe density of the ore layer in the reflow is shown;
fbdenotes the resistance coefficient of the reflow layer, fb＝3.5+44Sr1.44；
Sr represents the shrinkage of the ore layer during reflow,
Figure BDA0003568848270000106
Lprepresents the thickness of the ore layer before reflow;
l represents the thickness of the ore layer during reflow.
According to the above description, the calculation process of the drop zone pressure difference includes: obtaining slag iron retention rate, a harmonic mean of average coke particle size and average slag iron droplet diameter and a dropping belt coke void ratio in a coke layer during low-carbon blast furnace smelting, and calculating a dropping belt pressure loss gradient according to the slag iron retention rate, the harmonic mean of the average coke particle size and the average slag iron droplet diameter and the dropping belt coke void ratio in the coke layer; and acquiring the height of the dripping zone, and calculating the pressure difference of the dripping zone based on the height of the dripping zone and the pressure loss gradient of the dripping zone. Specifically, the calculation method of the drop zone pressure difference comprises the following steps:
Figure BDA0003568848270000111
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000112
representing a pressure loss gradient of the drip zone;
Figure BDA0003568848270000113
indicating the height of the drip zone;
htthe retention rate of iron slag in the coke layer is expressed;
dwrepresents the harmonic mean of the average particle size of the coke and the average diameter of the iron slag droplets;
εtrepresents the void ratio of the coke in the dripping zone;
ugrepresenting the empty furnace flow rate of the coal gas;
mu represents the kinetic viscosity of the gas.
In summary, the present embodiment provides a method for controlling the smelting cost of a low-carbon blast furnace, by obtaining the type of fuel and the unit cost of each fuel when smelting the low-carbon blast furnace; establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel; simultaneously obtaining constraint conditions when the low-carbon blast furnace smelting is carried out and a fuel proportioning range when the constraint conditions are met; and then calculating the minimum cost value of the smelting cost objective function in the fuel proportioning range, and outputting the fuel proportioning of the smelting cost objective function at the minimum cost value. Therefore, in the embodiment, a smelting cost objective function for controlling the smelting cost of the blast furnace is established according to the fuel type and the unit price of the fuel, and then the minimum value of the smelting cost objective function is determined by combining constraint conditions during smelting of the low-carbon blast furnace, and the fuel ratio corresponding to the minimum value of the smelting cost objective function is the optimal smelting cost scheme; the blast furnace smelting is carried out according to the fuel proportion corresponding to the minimum cost value, so that the influence of the fuel cost on the low-carbon blast furnace smelting can be linked, and the blast furnace can be ensured to stably and efficiently operate on the basis of high efficiency and low carbon, thereby obtaining an optimal blast furnace fuel scheme for low-cost smelting. Meanwhile, when blast furnace smelting is carried out, even if the fuel type and/or the unit price of the fuel are/is changed, the smelting scheme with the minimum cost is finally obtained, so that the embodiment can realize the smelting with the minimum cost of each low-carbon blast furnace under respective constraint conditions at any time according to market fluctuation.
Example 2:
as shown in fig. 2, the embodiment provides a method for controlling smelting cost of a low-carbon blast furnace, which comprises the following steps:
s100, generating a group of fuel proportions, and acquiring the maximum fuel supply amount input in advance; as an example, the pre-entered maximum fueling quantity may be a coke ratio of less than 400 kilograms per ton of iron, Xj<400 Kg/tFe; coal ratio less than 200kg per ton of iron, Xm<200 Kg/tFe; coke oven gas less than 200 cubic meters per ton of iron, Xg<200m3/TfE。
S200, judging whether material balance is met or not when low-carbon blast furnace smelting is carried out after hydrogen-rich gas is injected according to the generated fuel proportion and the input maximum fuel supply amount; if the material balance is met, the step S300 is executed; if the material balance is not met, returning to the step S100;
s300, judging whether heat balance is met or not when low-carbon blast furnace smelting is carried out after hydrogen-rich gas is injected, and if the heat balance is met, entering the step S400; if the thermal balance is not satisfied, returning to step S100;
s400, calculating the temperature distribution in the furnace when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected, and judging whether the temperature distribution in the furnace when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected meets the preset temperature condition of the blast furnace smelting or not; if the preset temperature condition of blast furnace smelting is met, the step S500 is carried out; if the preset temperature condition for blast furnace smelting is not met, returning to the step S100;
s500, calculating the pressure difference in the furnace when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected, and judging whether the error value of the calculated pressure difference in the furnace and the pressure difference in the standard furnace is larger than a preset error value or not; if the difference is larger than the preset error value, judging that the pressure difference in the furnace at the current moment does not meet the blast furnace smelting pressure difference condition, and returning to the step S100; if the current time is less than or equal to the preset error value, judging that the pressure difference in the furnace at the current time meets the blast furnace smelting pressure difference condition, and entering the step S600;
s600, establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel during low-furnace high-carbon smelting, obtaining a fuel proportioning range meeting the fuel supply amount, and calculating a cost value when the smelting cost objective function smelts a preset amount of steel and steel in the fuel proportioning range and meets smelting constraint conditions; and comparing the calculated minimum cost value with a pre-recorded fuel cost value for smelting a single ton of steel, and using the cost value with a smaller value as the pre-recorded fuel cost value for the next comparison. By way of example, in a blast furnace of an iron works, the fuel types may be coke, coal dust and coke oven gas, where the price of coke is 2.500 yuan/kg, the price of coal dust is 0.9 yuan/kg and the coke oven gas is 0.8 yuan/cubic meter, and the objective smelting cost function for smelting a single ton of steel may be: y 2.500 x Xj +0.900 x Xm +0.8 x Xg; in the formula, Xj represents a coke ratio, Xm represents a coal ratio, and Xg represents coke oven gas.
S700, judging whether the comparison frequency N is greater than or equal to a preset frequency Nmax, and if so, outputting the fuel ratio corresponding to the minimum cost value at the moment; if less, the process returns to step S100.
According to the above description, in the present embodiment, the step S200 of determining whether the material balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected according to the generated fuel ratio and the input maximum fuel supply amount includes: obtaining raw material components and blast furnace smelting process parameters during low-carbon blast furnace smelting, wherein the blast furnace smelting process parameters at least comprise: the element distribution rate, the slag alkalinity, the initial direct reduction degree of iron and the initial hydrogen-rich gas injection amount; calculating the amount of iron ore according to the element distribution ratio and the raw material components, and calculating the initial amount of the flux according to the alkalinity of the slag; calculating the amount of slag and the composition of the slag according to the amount of the iron ore, the initial amount of the molten metal, a preset initial coke ratio and a preset initial coal ratio; checking whether the basic oxides in the slag meet the desulfurization standard based on the calculated amount of the slag and the slag components; if the amount of the basic oxides in the slag does not meet the desulfurization standard, adjusting the initial melt amount and then recalculating new slag amount and slag components until the basic oxides in the slag meet the desulfurization standard; if so, calculating the components of the molten iron according to the components of the raw materials, the quantity of the iron ores, the quantity of the molten metal meeting the desulfurization standard, a preset initial coal ratio, a preset initial coke ratio and the element distribution rate; judging whether the molten iron components calculated by the kernel meet preset requirements or not; if the new molten iron composition does not meet the preset requirements, adjusting the preset initial coal ratio, the preset initial coke ratio and the initial hydrogen-rich gas injection amount, and recalculating the molten iron composition after the adjustment is completed; if so, calculating the air volume according to carbon brought by the fuel, carburization of the molten iron and carbon consumption of reduction of elements in the molten iron; calculating the gas quantity and the gas component of the tuyere raceway according to the calculated air quantity, the raw material components, the coke ratio when the molten iron component accounting is met, and the coal ratio when the molten iron component accounting is met, calculating the top gas component based on the gas quantity and the gas component of the tuyere raceway and the direct reduction of iron, and calculating the gas utilization rate according to the top gas component; judging whether the coal gas utilization rate is less than or equal to a preset thermodynamic limit value or not; if the current time is less than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the material balance; if the quantity of the coke is larger than the preset value, judging that the low-carbon blast furnace at the current moment does not meet the material balance, adjusting the preset initial coke ratio, the preset initial coal ratio, the initial hydrogen-rich gas injection quantity and the initial iron direct reduction degree, and judging the material balance of the low-carbon blast furnace again after the adjustment is finished until the material balance is met. As an example, the preset thermodynamic limit value in the present embodiment may be set according to actual conditions, for example, the preset thermodynamic limit value may be set to 49.5%. In the embodiment, the blast furnace meets the material balance after the hydrogen-rich medium is injected, and the coal gas utilization rate can meet the thermodynamic condition of iron oxide reduction.
According to the above description, in the present embodiment, the step S300 of determining whether the heat balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected includes: when the low-carbon blast furnace meets the material balance, acquiring a coke ratio meeting the material balance, a coal ratio meeting the material balance and a hydrogen-rich gas injection amount meeting the material balance, calculating a coke heat value according to the coke ratio meeting the material balance and a corresponding calorific value, calculating a coal specific heat value according to the coal ratio meeting the material balance and the corresponding calorific value, and calculating a hydrogen-rich gas heat value according to the hydrogen-rich gas meeting the material balance and the corresponding calorific value; obtaining a heat value brought when the air volume enters the low-carbon blast furnace and a heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace; adding the coke heat value, the coal specific heat value, the hydrogen-rich gas heat value, the heat value brought when the air volume enters the low-carbon blast furnace and the heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace, and taking the added result as a heat input value; calculating a difference value between the thermal income value and the thermal expenditure value, and judging whether a result obtained by dividing the difference value by the thermal income value is greater than or equal to a preset ratio or not; if the current time is greater than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the heat balance; if the current heat balance is smaller than the preset heat balance, judging that the low-carbon blast furnace at the current moment does not meet the heat balance, adjusting a preset initial coke ratio, a preset initial coal ratio, an initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the heat balance of the low-carbon blast furnace again; wherein the thermal payout values include, but are not limited to: the decomposition heat of the oxide brought by the ore, the decomposition heat of the oxide brought by the coke, the decomposition heat of the oxide brought by the coal powder, the heat consumed by iron reduction, the heat consumed by silicon reduction, the heat consumed by manganese reduction, the heat consumed by phosphorus reduction, the heat consumed by sulfur reduction, the enthalpy of molten iron, the enthalpy of slag, the enthalpy of coal gas and the heat value of coal gas. As an example, the preset ratio in the present embodiment may be set according to actual conditions, for example, the preset ratio may be set to 5%. According to the embodiment, the blast furnace can meet the heat balance after the hydrogen-rich medium is injected, and the heat balance of the blast furnace can be ensured.
According to the above description, in this embodiment, the step S400 of determining whether the temperature distribution in the furnace during the low-carbon blast furnace smelting after the hydrogen-rich gas is injected satisfies the preset temperature condition for blast furnace smelting includes: when the low-carbon blast furnace meets the heat balance, calculating the theoretical combustion temperature according to the gas quantity and the gas components in the tuyere raceway; calculating the material water equivalent and the gas water equivalent of the low-carbon blast furnace, and obtaining the temperature distribution from a zero stock line to a tuyere on the basis of the material water equivalent and the gas water equivalent; determining the position and width of a reflow zone and the height of a reduction temperature zone according to the furnace temperature and the reflow temperature of the ore in the temperature distribution; judging whether the position of the reflow zone and the height of the reduction temperature zone are in a preset interval, and if so, judging that the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when low-carbon blast furnace smelting is carried out at the current moment; if the temperature distribution is not in the preset interval, adjusting the blast parameters, the preset initial coke ratio, the preset initial coal ratio and the initial hydrogen-rich gas injection amount, and judging whether the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when the low-carbon blast furnace smelting is carried out again. As an example, the preset interval in the present embodiment may be set for each blast furnace. According to the embodiment, after the hydrogen-rich medium is injected, the temperature distribution in the blast furnace meets the preset temperature condition, and the position of the blast furnace reflow zone and the indirect reduction zone can be ensured to be proper. Specifically, a temperature distribution from the zero stock line to the tuyere is obtained based on the material water equivalent and the gas water equivalent, and there are:
Figure BDA0003568848270000141
in the formula, ωs＝mscsRepresents the material water equivalent;
ωg＝mgcgrepresents the equivalent of gas water;
q represents the volume of the iron material per ton;
kvexpressing the comprehensive heat exchange coefficient of unit furnace burden and coal gas;
z represents the height of the calculation point from the starting point;
v represents the volume of material descending per second;
r represents the radius at the point of initiation of the calculation;
r represents the radius at the end of the calculation;
h represents the height of the furnace body;
tg(Z) represents the gas temperature at Z;
ts(Z) represents the temperature of the material at Z.
According to the above descriptions, in this embodiment, the step S500 of determining whether the calculated error value between the furnace internal pressure difference and the standard furnace internal pressure difference is greater than the preset error value includes: acquiring pre-calculated block belt pressure difference, reflow belt pressure difference and dripping belt pressure difference; adding the block belt pressure difference, the reflow belt pressure difference and the dripping belt pressure difference, and taking the addition result as the furnace pressure difference during the low-carbon blast furnace smelting at the current moment; calculating an error value of the pressure difference in the furnace and the pressure difference in the standard furnace at the current moment, and judging whether the error value is greater than a preset error value or not; if the difference is larger than the preset difference, the furnace pressure difference when the low-carbon blast furnace smelting is carried out at the current moment is judged not to meet the blast furnace smelting pressure difference condition, and the fuel ratio when the block belt pressure difference, the reflow belt pressure difference and the dropping belt pressure difference are calculated is adjusted and calculated again until the error value is smaller than or equal to the preset error value; and if the pressure difference is smaller than or equal to the preset value, judging that the pressure difference in the furnace meets the condition of the blast furnace smelting pressure difference when the low-carbon blast furnace smelting is carried out at the current moment. As an example, the standard furnace differential pressure in the embodiment may be the same type of blast furnace differential pressure, and the preset error value may be set according to the actual situation, for example, the preset error value may be set to 10%. In the embodiment, the pressure difference in the blast furnace after the hydrogen-rich medium is injected meets the smelting pressure difference condition of the blast furnace, so that the blast furnace can be ensured to run stably and smoothly.
According to the above description, the process of calculating the block belt pressure difference includes: obtaining average grain size of furnace burden, block belt void ratio, shape coefficient of furnace burden, empty furnace flow rate of furnace gas, density of furnace gas and dynamic viscosity of furnace gas when low-carbon blast furnace smelting is carried out, and calculating block belt pressure loss gradient according to the average grain size of furnace burden, the block belt void ratio, the shape coefficient of furnace burden, the empty furnace flow rate of furnace gas, the density of furnace gas and the dynamic viscosity of furnace gas; obtaining a predetermined position of a reflow belt, and determining the height of a block belt according to the position of the reflow belt; and calculating the corresponding block belt pressure difference based on the height of the block belt and the pressure loss gradient of the block belt. Specifically, the calculation of the bulk band pressure difference includes:
Figure BDA0003568848270000151
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000152
representing a bulk ribbon pressure loss gradient;
Figure BDA0003568848270000153
expressed as the height of the block belt;
dprepresents the average particle size of the charge;
ε represents the blocky band void fraction;
Figure BDA0003568848270000154
representing a charge shape factor;
ugrepresenting the empty furnace flow rate of the coal gas;
ρgrepresents the density of the gas;
mu represents the kinetic viscosity of the coal gas.
According to the above description, the calculation process of the reflow belt pressure difference includes: obtaining the void ratio of a reflow zone, the density of a ore layer before reflow, the density of the ore layer during reflow, the thickness of an ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow during low-carbon blast furnace smelting, and calculating the pressure loss gradient of the reflow zone according to the void ratio of the reflow zone, the density of the ore layer before reflow, the density of the ore layer during reflow, the thickness of the ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow; and acquiring the width of the reflow belt, and calculating the corresponding reflow belt pressure difference based on the width of the reflow belt and the pressure loss gradient of the reflow belt. Specifically, the calculation method of the reflow belt pressure difference comprises the following steps:
Figure BDA0003568848270000161
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000162
representing a pressure loss gradient of the reflow belt;
Figure BDA0003568848270000163
expressed as the width of the reflow ribbon;
εbthe ratio of voids in the reflow zone is shown,
Figure BDA0003568848270000164
ρprepresenting the density of the ore layer before the reflow;
ρbthe density of the ore layer in the reflow is shown;
fbdenotes the resistance coefficient of the reflow layer, fb＝3.5+44Sr1.44；
Sr represents the shrinkage of the ore layer during reflow,
Figure BDA0003568848270000165
Lprepresents the thickness of the ore layer before reflow;
l represents the thickness of the ore layer during reflow.
According to the above description, the calculation process of the drop zone pressure difference includes: obtaining slag iron retention rate, a harmonic mean of average coke particle size and average slag iron droplet diameter and a dropping belt coke void ratio in a coke layer during low-carbon blast furnace smelting, and calculating a dropping belt pressure loss gradient according to the slag iron retention rate, the harmonic mean of the average coke particle size and the average slag iron droplet diameter and the dropping belt coke void ratio in the coke layer; and acquiring the height of the dripping zone, and calculating the pressure difference of the dripping zone based on the height of the dripping zone and the pressure loss gradient of the dripping zone. Specifically, the calculation method of the drop zone pressure difference comprises the following steps:
Figure BDA0003568848270000166
in the formula (I), the compound is shown in the specification,
Figure BDA0003568848270000167
representing a drop zone pressure loss gradient;
Figure BDA0003568848270000168
indicating the height of the drip zone;
htthe retention rate of iron slag in the coke layer is expressed;
dwrepresents the harmonic mean of the average particle size of the coke and the average diameter of the iron slag droplets;
represents the void ratio of the coke in the dripping zone;
ugrepresenting the empty furnace flow rate of the coal gas;
mu represents the kinetic viscosity of the gas.
According to the above description, in one embodiment, the types of fuel in the blast furnace of a certain ironworks are coke, pulverized coal and coke oven gas, respectively, in which caseThe price of coke is 2.500 yuan/kg, the price of coal powder is 0.9 yuan/kg, and the price of coke oven gas is 0.8 yuan/cubic meter, so the smelting cost objective function when smelting single ton of steel can be as follows: y 2.500 x Xj +0.900 x Xm +0.8 x Xg; in the formula, Xj represents a coke ratio, Xm represents a coal ratio, and Xg represents coke oven gas. The maximum fuel supply amount inputted in advance is the coke ratio Xj<400Kg/tFe, coal ratio Xm<200Kg/tFe, coke oven gas Xg<200m3and/tFe. At the moment, when the blast furnace smelting meets the material balance and the heat balance, the coke reduction is required to be more than 200 Kg/tFe; the temperature distribution in the blast furnace needs to meet the requirement of 800-1200 ℃ and the height of the blast furnace is more than 18 m; the pressure difference in the blast furnace smelting furnace needs to meet the requirement of delta P<200 Kpa. After comparing the smelting costs for 2000 times, the minimum cost value of the cost objective function is obtained, namely: y is 2.500 x 330+0.900 x 150+0.8 x 100-1040 yuan, the coke ratio Xj is 330Kg/tFe, the coal ratio Xm is 150Kg/tFe, the coke oven gas Xg is 100m3/tFe。
In summary, the present embodiment provides a method for controlling smelting cost of a low-carbon blast furnace, by obtaining the type of fuel and the cost unit price of each fuel when smelting the low-carbon blast furnace; establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel; simultaneously obtaining constraint conditions for low-carbon blast furnace smelting and a fuel proportioning range when the constraint conditions are met; and then calculating the minimum cost value of the smelting cost objective function in the fuel proportioning range, and outputting the fuel proportioning of the smelting cost objective function at the minimum cost value. Therefore, in the embodiment, a smelting cost objective function for controlling the smelting cost of the blast furnace is established according to the fuel type and the unit price of the fuel, and then the minimum value of the smelting cost objective function is determined by combining constraint conditions during smelting of the low-carbon blast furnace, and the fuel ratio corresponding to the minimum value of the smelting cost objective function is the optimal smelting cost scheme; the blast furnace smelting is carried out according to the fuel proportion corresponding to the minimum cost value, so that the influence of the fuel cost on the low-carbon blast furnace smelting can be linked, and the blast furnace can be ensured to stably and efficiently operate on the basis of high efficiency and low carbon, thereby obtaining an optimal blast furnace fuel scheme for low-cost smelting. Meanwhile, when blast furnace smelting is carried out, even if the fuel type and/or the unit price of the fuel are/is changed, the smelting scheme with the minimum cost is finally obtained, so that the embodiment can realize the smelting with the minimum cost of each low-carbon blast furnace under respective constraint conditions at any time according to market fluctuation.
Example 3:
as shown in FIG. 3, the invention provides a low-carbon blast furnace smelting cost control system, which comprises a client subsystem and a background processing subsystem; the client subsystem is used for inputting the fuel type for low-carbon blast furnace smelting, the cost unit price of each fuel, the constraint condition for low-carbon blast furnace smelting and the fuel proportion for displaying the smelting cost objective function at the minimum cost value; the background processing subsystem is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel, acquiring a fuel proportioning range meeting all constraint conditions, and calculating a cost value when the smelting cost objective function is in the fuel proportioning range, smelts a preset amount of steel and meets the smelting constraint conditions.
According to the above, the background processing subsystem comprises:
the material balance module is used for judging whether the material balance is met or not when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected; specifically, raw material components and blast furnace smelting process parameters during low-carbon blast furnace smelting are obtained, and the blast furnace smelting process parameters at least comprise: the element distribution rate, the slag alkalinity, the initial direct reduction degree of iron and the initial hydrogen-rich gas injection amount; calculating the amount of iron ore according to the element distribution rate and the raw material components, and calculating the initial amount of the melt according to the slag alkalinity; calculating the amount of slag and the composition of the slag according to the amount of the iron ore, the amount of the initial melt, a preset initial coke ratio and a preset initial coal ratio; checking whether the basic oxides in the slag meet the desulfurization standard based on the calculated amount of the slag and the slag components; if the amount of the basic oxides in the slag does not meet the desulfurization standard, adjusting the initial melt amount and then recalculating new slag amount and slag components until the basic oxides in the slag meet the desulfurization standard; if so, calculating the components of the molten iron according to the components of the raw materials, the quantity of the iron ores, the quantity of the molten metal meeting the desulfurization standard, a preset initial coal ratio, a preset initial coke ratio and the element distribution rate; judging whether the molten iron components calculated by the kernel meet preset requirements or not; if the new molten iron composition does not meet the preset requirements, adjusting the preset initial coal ratio, the preset initial coke ratio and the initial hydrogen-rich gas injection amount, and recalculating the molten iron composition after the adjustment is completed; if so, calculating the air volume according to carbon brought by the fuel, carburization of the molten iron and carbon consumption of element reduction in the molten iron; calculating the gas quantity and the gas component of the tuyere raceway according to the calculated air quantity, the raw material components, the coke ratio when the molten iron component accounting is met, and the coal ratio when the molten iron component accounting is met, calculating the top gas component based on the gas quantity and the gas component of the tuyere raceway and the direct reduction of iron, and calculating the gas utilization rate according to the top gas component; judging whether the coal gas utilization rate is less than or equal to a preset thermodynamic limit value or not; if the current time is less than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the material balance; if the quantity of the coke is larger than the preset value, judging that the low-carbon blast furnace at the current moment does not meet the material balance, adjusting the preset initial coke ratio, the preset initial coal ratio, the initial hydrogen-rich gas injection quantity and the initial iron direct reduction degree, and judging the material balance of the low-carbon blast furnace again after the adjustment is finished until the material balance is met. As an example, the preset thermodynamic limit value in the present embodiment may be set according to actual conditions, for example, the preset thermodynamic limit value may be set to 49.5%. In the embodiment, the blast furnace meets the material balance after the hydrogen-rich medium is injected, and the coal gas utilization rate can meet the thermodynamic condition of iron oxide reduction.
The heat balance module is used for judging whether the heat balance is met or not when the low-carbon blast furnace is smelted after hydrogen-rich gas is injected after the low-carbon blast furnace meets the material balance; specifically, when the low-carbon blast furnace meets the material balance, acquiring a coke ratio when the material balance is met, a coal ratio when the material balance is met and a hydrogen-rich gas injection amount when the material balance is met, calculating a coke heat value according to the coke ratio when the material balance is met and a corresponding calorific value, calculating a coal specific heat value according to the coal ratio when the material balance is met and the corresponding calorific value, and calculating the hydrogen-rich gas heat value according to the hydrogen-rich gas when the material balance is met and the corresponding calorific value; obtaining a heat value brought when the air volume enters the low-carbon blast furnace and a heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace; adding the coke heat value, the coal specific heat value, the hydrogen-rich gas heat value, the heat value brought when the air volume enters the low-carbon blast furnace and the heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace, and taking the added result as a heat input value; calculating a difference value between the thermal income value and the thermal expenditure value, and judging whether a result obtained by dividing the difference value by the thermal income value is greater than or equal to a preset ratio or not; if the current time is greater than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the heat balance; if the current heat balance is smaller than the preset heat balance, judging that the low-carbon blast furnace at the current moment does not meet the heat balance, adjusting a preset initial coke ratio, a preset initial coal ratio, an initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the heat balance of the low-carbon blast furnace again; wherein the thermal payout values include, but are not limited to: the heat of decomposition of oxides carried by ores, the heat of decomposition of oxides carried by coke, the heat of decomposition of oxides carried by coal dust, the heat consumed by iron reduction, the heat consumed by silicon reduction, the heat consumed by manganese reduction, the heat consumed by phosphorus reduction, the heat consumed by sulfur reduction, the enthalpy of molten iron, the enthalpy of slag, the enthalpy of gas, and the calorific value of gas. As an example, the preset ratio in the present embodiment may be set according to actual conditions, for example, the preset ratio may be set to 5%. According to the embodiment, the blast furnace can meet the heat balance after the hydrogen-rich medium is injected, and the heat balance of the blast furnace can be ensured.
The furnace internal temperature module is used for judging whether the temperature distribution in the furnace during low-carbon blast furnace smelting after hydrogen-rich gas injection meets the preset temperature condition for blast furnace smelting after the low-carbon blast furnace meets the heat balance; specifically, when the low-carbon blast furnace meets the heat balance, the theoretical combustion temperature is calculated according to the gas quantity and the gas components in the tuyere raceway; calculating the material water equivalent and the coal gas water equivalent of the low-carbon blast furnace, and obtaining the temperature distribution from a zero material line to a tuyere based on the material water equivalent and the coal gas water equivalent; determining the position and width of a reflow zone and the height of a reduction temperature zone according to the furnace temperature and the reflow temperature of the ore in the temperature distribution; judging whether the position of the reflow zone and the height of the reduction temperature zone are in a preset interval, and if so, judging that the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when low-carbon blast furnace smelting is carried out at the current moment; if the temperature distribution is not in the preset interval, adjusting the blast parameters, the preset initial coke ratio, the preset initial coal ratio and the initial hydrogen-rich gas injection amount, and judging whether the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when the low-carbon blast furnace smelting is carried out again. As an example, the preset interval in the present embodiment may be set for each blast furnace. According to the embodiment, after the hydrogen-rich medium is injected, the temperature distribution in the blast furnace meets the preset temperature condition, and the position of the blast furnace reflow zone and the indirect reduction zone can be ensured to be proper.
The furnace internal pressure difference module is used for judging whether the furnace internal pressure difference meets the blast furnace smelting pressure difference condition when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected after the temperature distribution in the furnace meets the preset blast furnace smelting temperature condition; specifically, a block belt pressure difference, a reflow belt pressure difference and a dripping belt pressure difference which are calculated in advance are obtained; adding the block belt pressure difference, the reflow belt pressure difference and the dripping belt pressure difference, and taking the addition result as the furnace pressure difference during the low-carbon blast furnace smelting at the current moment; calculating an error value of the pressure difference in the furnace and the pressure difference in the standard furnace at the current moment, and judging whether the error value is greater than a preset error value or not; if the difference is larger than the preset difference, the furnace pressure difference when the low-carbon blast furnace smelting is carried out at the current moment is judged not to meet the blast furnace smelting pressure difference condition, and the fuel ratio when the block belt pressure difference, the reflow belt pressure difference and the dropping belt pressure difference are calculated is adjusted and calculated again until the error value is smaller than or equal to the preset error value; and if the pressure difference is smaller than or equal to the preset value, judging that the pressure difference in the furnace meets the condition of the blast furnace smelting pressure difference when the low-carbon blast furnace smelting is carried out at the current moment. As an example, the standard furnace pressure difference in the embodiment may be the same type of blast furnace pressure difference, and the preset error value may be set according to an actual situation, for example, the preset error value may be set to 10%. According to the embodiment, the pressure difference in the blast furnace after the hydrogen-rich medium is injected meets the smelting pressure difference condition of the blast furnace, so that the blast furnace can be ensured to stably and smoothly move.
The objective function module is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel; if the fuel types are coke, coal powder and coke oven gas, respectively, and the price of the coke is 2.500 yuan/kg, the price of the coal powder is 0.9 yuan/kg, and the price of the coke oven gas is 0.8 yuan/cubic meter, the objective function of the smelting cost when smelting a single ton of steel can be as follows: y 2.500 x Xj +0.900 x Xm +0.8 x Xg; in the formula, Xj represents a coke ratio, Xm represents a coal ratio, and Xg represents coke oven gas.
And the cost calculation module is used for acquiring a fuel proportioning range meeting the fuel supply quantity and calculating the cost value when the smelting cost objective function is in the fuel proportioning range, a preset amount of steel is smelted and smelting constraint conditions are met.
According to the above, the client subsystem comprises:
the input module is used for inputting the fuel type when the low-carbon blast furnace smelting is carried out, the cost unit price of each fuel and the constraint condition when the low-carbon blast furnace smelting is carried out; as an example, the input fuel categories may be coke, coal dust, and coke oven gas; the price of coke is 2.500 yuan/kg, the price of coal powder is 0.9 yuan/kg, and the price of coke oven gas is 0.8 yuan/cubic meter; constraints for the inputs include, but are not limited to: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas. And the display module is used for displaying the minimum cost value of the smelting cost objective function and displaying the fuel ratio corresponding to the smelting cost objective function at the minimum cost value.
In summary, the present embodiment provides a low-carbon blast furnace smelting cost control system, which inputs the fuel type for low-carbon blast furnace smelting, the cost unit price of each fuel, the constraint condition for low-carbon blast furnace smelting, and the fuel ratio for displaying the smelting cost objective function at the minimum cost value through a client-side subsystem; and establishing a smelting cost objective function through a background processing subsystem according to the fuel category and the cost unit price of each fuel, acquiring a fuel proportioning range when all constraint conditions are met, and calculating the minimum cost value of the smelting cost objective function when a preset amount of steel is smelted in the fuel proportioning range. Therefore, in the embodiment, a smelting cost objective function for controlling the smelting cost of the blast furnace is established according to the fuel type and the unit price of the fuel, and then the minimum value of the smelting cost objective function is determined by combining constraint conditions during smelting of the low-carbon blast furnace, and the fuel ratio corresponding to the minimum value of the smelting cost objective function is the optimal smelting cost scheme; the blast furnace smelting is carried out according to the fuel proportion corresponding to the minimum cost value, so that the influence of the fuel cost on the low-carbon blast furnace smelting can be linked, and the blast furnace can be ensured to stably and efficiently operate on the basis of high efficiency and low carbon, thereby obtaining an optimal blast furnace fuel scheme for low-cost smelting. Meanwhile, when blast furnace smelting is carried out, even if the fuel type and/or the unit price of the fuel are/is changed, the smelting scheme with the minimum cost is finally obtained, so that the embodiment can realize the smelting with the minimum cost of each low-carbon blast furnace under respective constraint conditions at any time according to market fluctuation. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims (12)

1. The method for controlling the smelting cost of the low-carbon blast furnace is characterized by comprising the following steps of:
acquiring the type of fuel and the cost unit price of each fuel when low-carbon blast furnace smelting is carried out;
establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel;
obtaining constraint conditions for low-carbon blast furnace smelting and fuel proportioning ranges meeting all the constraint conditions;
calculating the cost value of the smelting cost objective function in the fuel proportioning range when the smelting cost objective function meets smelting constraint conditions, and outputting the fuel proportioning of the smelting cost objective function at the minimum cost value;
wherein, the constraint conditions for smelting the low-carbon blast furnace comprise at least one of the following conditions: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas.
2. The method for controlling the smelting cost of the low-carbon blast furnace according to claim 1, further comprising the step of judging whether the material balance is met when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected, wherein the method comprises the following steps:
obtaining raw material components and blast furnace smelting technological parameters during low-carbon blast furnace smelting, wherein the blast furnace smelting technological parameters at least comprise: the element distribution rate, the slag alkalinity, the initial direct reduction degree of iron and the initial hydrogen-rich gas injection amount;
calculating the amount of iron ore according to the element distribution ratio and the raw material components, and calculating the initial amount of the flux according to the alkalinity of the slag;
calculating the amount of slag and the composition of the slag according to the amount of the iron ore, the initial amount of the molten metal, a preset initial coke ratio and a preset initial coal ratio;
checking whether the basic oxides in the slag meet the desulfurization standard based on the calculated amount of the slag and the slag components; if the amount of the basic oxides in the slag does not meet the desulfurization standard, adjusting the initial melt amount and then recalculating new slag amount and slag components until the basic oxides in the slag meet the desulfurization standard; if so, calculating the utilization rate of the gas based on the gas quantity, the gas components and the direct reduction degree of the initial iron in the tuyere raceway;
judging whether the coal gas utilization rate is less than or equal to a preset thermodynamic limit value or not; if the current time is less than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the material balance; if the initial coke ratio is larger than the initial coal ratio, judging that the low-carbon blast furnace at the current moment does not meet the material balance, adjusting the preset initial coke ratio, the preset initial coal ratio, the initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the material balance of the low-carbon blast furnace again after the adjustment is finished until the material balance is met.
3. The method for controlling the smelting cost of the low-carbon blast furnace according to claim 2, wherein the step of calculating the utilization rate of the gas based on the amount and components of the gas in the tuyere raceway and the direct reduction degree of the initial iron comprises the steps of:
after the basic oxides in the slag meet the desulfurization standard, calculating the components of the molten iron according to the raw material components, the amount of the iron ore, the amount of the molten metal meeting the desulfurization standard, a preset initial coal ratio, a preset initial coke ratio and the element distribution ratio;
judging whether the molten iron components calculated by the kernel meet preset requirements or not; if the new molten iron composition does not meet the preset requirements, adjusting the preset initial coal ratio, the preset initial coke ratio and the initial hydrogen-rich gas injection amount, and recalculating the molten iron composition after the adjustment is completed; if so, calculating the air volume according to carbon brought by the fuel, carburization of the molten iron and carbon consumption of element reduction in the molten iron;
and calculating the gas quantity and the gas component of the tuyere raceway according to the calculated air quantity, the raw material components, the coke ratio when the molten iron component accounting is met, and the coal ratio when the molten iron component accounting is met, and calculating the gas utilization rate based on the gas quantity and the gas component of the tuyere raceway and the direct reduction of the initial iron.
4. The method for controlling the smelting cost of the low-carbon blast furnace according to claim 2 or 3, further comprising judging whether the heat balance is satisfied when the low-carbon blast furnace smelting is performed after the hydrogen-rich gas is injected, and the following steps are performed:
when the low-carbon blast furnace meets the material balance, acquiring a coke ratio meeting the material balance, a coal ratio meeting the material balance and a hydrogen-rich gas injection amount meeting the material balance, calculating a coke heat value according to the coke ratio meeting the material balance and a corresponding calorific value, calculating a coal specific heat value according to the coal ratio meeting the material balance and the corresponding calorific value, and calculating a hydrogen-rich gas heat value according to the hydrogen-rich gas meeting the material balance and the corresponding calorific value;
obtaining a heat value brought when the air volume enters the low-carbon blast furnace and a heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace;
adding the coke heat value, the coal specific heat value, the hydrogen-rich gas heat value, the heat value brought when the air volume enters the low-carbon blast furnace and the heat value brought when the hydrogen-rich gas is blown into the low-carbon blast furnace, and taking the added result as a heat input value;
calculating a difference value between the thermal income value and the thermal expenditure value, and judging whether a result obtained by dividing the difference value by the thermal income value is greater than or equal to a preset ratio or not; if the current time is more than or equal to the preset time, judging that the low-carbon blast furnace at the current time meets the heat balance; if the current heat balance is smaller than the preset heat balance, judging that the low-carbon blast furnace at the current moment does not meet the heat balance, adjusting a preset initial coke ratio, a preset initial coal ratio, an initial hydrogen-rich gas injection amount and the initial iron direct reduction degree, and judging the heat balance of the low-carbon blast furnace again;
wherein the thermal payout value comprises at least one of: the heat of decomposition of oxides carried by ores, the heat of decomposition of oxides carried by coke, the heat of decomposition of oxides carried by coal dust, the heat consumed by iron reduction, the heat consumed by silicon reduction, the heat consumed by manganese reduction, the heat consumed by phosphorus reduction, the heat consumed by sulfur reduction, the enthalpy of molten iron, the enthalpy of slag, the enthalpy of gas, and the calorific value of gas.
5. The method for controlling the smelting cost of the low-carbon blast furnace according to claim 4, wherein the method further comprises the step of judging whether the temperature distribution in the furnace during the low-carbon blast furnace smelting after the hydrogen-rich gas is injected meets the preset temperature condition for the blast furnace smelting, and the method comprises the following steps:
when the low-carbon blast furnace meets the heat balance, calculating the theoretical combustion temperature according to the gas quantity and the gas components in the tuyere raceway;
calculating the material water equivalent and the coal gas water equivalent of the low-carbon blast furnace, and obtaining the temperature distribution from a zero material line to a tuyere based on the material water equivalent and the coal gas water equivalent;
determining the position and width of a reflow zone and the height of a reduction temperature zone according to the furnace temperature and the reflow temperature of the ore in the temperature distribution;
judging whether the position of the reflow zone and the height of the reduction temperature zone are in a preset interval, and if so, judging that the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when low-carbon blast furnace smelting is carried out at the current moment; if the temperature distribution is not in the preset interval, adjusting the blast parameters, the preset initial coke ratio, the preset initial coal ratio and the initial hydrogen-rich gas injection amount, and judging whether the temperature distribution in the furnace meets the preset temperature condition for blast furnace smelting when the low-carbon blast furnace smelting is carried out again.
6. The method for controlling the smelting cost of the low-carbon blast furnace according to claim 1 or 5, further comprising judging whether the pressure difference in the furnace during the low-carbon blast furnace smelting after the hydrogen-rich gas is injected meets the pressure difference condition of the blast furnace smelting, and comprising the following steps:
acquiring pre-calculated block belt pressure difference, reflow belt pressure difference and dripping belt pressure difference;
adding the block belt pressure difference, the reflow belt pressure difference and the dripping belt pressure difference, and taking the addition result as the furnace pressure difference during the low-carbon blast furnace smelting at the current moment;
calculating an error value of the pressure difference in the furnace and the pressure difference in the standard furnace at the current moment, and judging whether the error value is greater than a preset error value or not;
if the difference is larger than the preset difference, the furnace pressure difference when the low-carbon blast furnace smelting is carried out at the current moment is judged not to meet the blast furnace smelting pressure difference condition, and the fuel ratio when the block belt pressure difference, the reflow belt pressure difference and the dropping belt pressure difference are calculated is adjusted and calculated again until the error value is smaller than or equal to the preset error value;
and if the pressure difference is smaller than or equal to the preset value, judging that the pressure difference in the furnace meets the condition of the blast furnace smelting pressure difference when the low-carbon blast furnace smelting is carried out at the current moment.
7. The low-carbon blast furnace smelting cost control method according to claim 6, wherein the calculation process of the block belt pressure difference comprises the following steps:
obtaining average grain size of furnace burden, block belt void ratio, shape coefficient of furnace burden, empty furnace flow rate of furnace gas, density of furnace gas and dynamic viscosity of furnace gas when low-carbon blast furnace smelting is carried out, and calculating block belt pressure loss gradient according to the average grain size of furnace burden, the block belt void ratio, the shape coefficient of furnace burden, the empty furnace flow rate of furnace gas, the density of furnace gas and the dynamic viscosity of furnace gas;
obtaining a predetermined position of a reflow belt, and determining the height of a block belt according to the position of the reflow belt;
and calculating the corresponding block belt pressure difference based on the height of the block belt and the pressure loss gradient of the block belt.
8. The low-carbon blast furnace smelting cost control method according to claim 6, wherein the calculation process of the reflow band pressure difference comprises the following steps:
obtaining the void ratio of a reflow zone, the density of an ore layer before reflow, the density of the ore layer during reflow, the thickness of an ore layer before reflow, the thickness of an ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow, and calculating the pressure loss gradient of the reflow zone according to the void ratio of the reflow zone, the density of the ore layer before reflow, the density of the ore layer during reflow, the thickness of the ore layer before reflow, the thickness of the ore layer during reflow, the resistance coefficient of the reflow layer and the shrinkage rate of the ore layer during reflow;
and acquiring the width of the reflow belt, and calculating the corresponding reflow belt pressure difference based on the width of the reflow belt and the pressure loss gradient of the reflow belt.
9. The low-carbon blast furnace smelting cost control method according to claim 6, wherein the calculation process of the pressure difference of the dripping zone comprises the following steps:
obtaining slag iron retention rate, a harmonic mean of average coke particle size and average slag iron droplet diameter and a dropping belt coke void ratio in a coke layer during low-carbon blast furnace smelting, and calculating a dropping belt pressure loss gradient according to the slag iron retention rate, the harmonic mean of the average coke particle size and the average slag iron droplet diameter and the dropping belt coke void ratio in the coke layer;
and acquiring the height of the dripping zone, and calculating the pressure difference of the dripping zone based on the height of the dripping zone and the pressure loss gradient of the dripping zone.
10. The low-carbon blast furnace smelting cost control system is characterized by comprising a client subsystem and a background processing subsystem;
the client subsystem is used for inputting the type of fuel for low-carbon blast furnace smelting, the cost unit price of each fuel, constraint conditions for low-carbon blast furnace smelting and the fuel ratio for displaying the smelting cost objective function at the minimum cost value;
the background processing subsystem is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel, acquiring a fuel proportioning range meeting all constraint conditions, and calculating a cost value of the smelting cost objective function meeting the smelting constraint conditions in the fuel proportioning range;
wherein, the constraint conditions for smelting the low-carbon blast furnace comprise at least one of the following conditions: the fuel supply amount, the material balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the heat balance when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, the temperature distribution in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas, and the pressure difference in the furnace when performing low-carbon blast furnace smelting after injecting hydrogen-rich gas.
11. The low carbon blast furnace smelting cost control system of claim 10, wherein the background processing subsystem comprises:
the material balance module is used for judging whether the material balance is met or not when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected;
the heat balance module is used for judging whether the heat balance is met or not when the low-carbon blast furnace is smelted after hydrogen-rich gas is injected after the low-carbon blast furnace meets the material balance;
the furnace internal temperature module is used for judging whether the temperature distribution in the furnace during low-carbon blast furnace smelting after hydrogen-rich gas injection meets the preset temperature condition for blast furnace smelting after the low-carbon blast furnace meets the heat balance;
the furnace internal pressure difference module is used for judging whether the furnace internal pressure difference meets the blast furnace smelting pressure difference condition when the low-carbon blast furnace smelting is carried out after the hydrogen-rich gas is injected after the temperature distribution in the furnace meets the preset blast furnace smelting temperature condition;
the objective function module is used for establishing a smelting cost objective function according to the fuel type and the cost unit price of each fuel;
and the cost calculation module is used for acquiring a fuel proportioning range meeting the fuel supply quantity and calculating the cost value when the smelting cost objective function is in the fuel proportioning range and meets the smelting constraint condition.
12. The low carbon blast furnace smelting cost control system according to claim 10 or 11, wherein the client subsystem comprises:
the input module is used for inputting the fuel type when the low-carbon blast furnace smelting is carried out, the cost unit price of each fuel and the constraint condition when the low-carbon blast furnace smelting is carried out;
and the display module is used for displaying the minimum cost value of the smelting cost objective function and displaying the fuel ratio corresponding to the smelting cost objective function at the minimum cost value.
CN202210315374.7A 2022-03-28 2022-03-28 Low-carbon blast furnace smelting cost control method and system Pending CN114662767A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115216569A (en) * 2022-07-22 2022-10-21 北京科技大学 Method for regulating and controlling technological parameters of blast furnace blowing flux through theoretical combustion temperature

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115216569A (en) * 2022-07-22 2022-10-21 北京科技大学 Method for regulating and controlling technological parameters of blast furnace blowing flux through theoretical combustion temperature
CN115216569B (en) * 2022-07-22 2023-06-27 北京科技大学 Method for regulating and controlling process parameters of blast furnace blowing flux through theoretical combustion temperature

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