A method for predicting gas consumption of hot blast stoves based on judgment of hot and cold stoves

Abstract

The present invention provides a method for predicting the gas consumption of a hot blast furnace based on the judgment of the hot blast furnace being cold or hot, which belongs to the field of energy-saving technology in the steel industry. In order to solve the technical problem of how to increase the hot blast temperature while reducing the consumption of the hot blast furnace, the technical solution adopted by the present invention includes: based on the parameter dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟 , determine the furnace condition of the hot blast furnace after the furnace is replaced; according to the determined furnace condition, calculate the residual heat of the hot blast furnace after heat exchange; according to the calculated residual heat of the hot blast furnace, predict the amount of gas for burning the furnace based on the furnace condition. The method of the present invention fully considers the energy conversion of the hot blast furnace in the heat exchange process, predicts the gas heat load required for each combustion according to the cold and hot furnace states, ensures the hot blast temperature is stable while reducing fuel consumption, provides accurate data support for the prediction of the single gas consumption of the hot blast furnace, and realizes the precise control of the hot blast furnace.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation in the steel industry, and in particular to a method for predicting gas consumption of a hot blast furnace based on determining whether the hot blast furnace is a cold furnace or a hot furnace. Background Art

[0002] The ironmaking process is the largest energy consumer in the steel industry, accounting for more than 60% of the total comprehensive energy consumption. Reducing the energy consumption of the ironmaking process is an important means to solve the energy consumption problem in the steel industry. The main energy-consuming equipment in the ironmaking process is the blast furnace and the hot blast furnace. The blast furnace uses a reduction reaction to convert iron oxides into iron-carbon alloys to provide raw materials for the next step of steelmaking and rolling. The hot blast furnace provides hot air at a suitable temperature for the blast furnace. Experience shows that every increase of 100°C in the hot air temperature reduces the blast furnace coke ratio by 3% to 7%. At the same time, the hot blast furnace is also the main gas fuel consumer in the blast furnace process, and its energy consumption accounts for more than 14% of the blast furnace process. How to increase the hot air temperature while reducing the consumption of the hot blast furnace is a difficult problem that needs to be solved in the ironmaking process.

[0003] With the continuous deepening of blast furnace intelligence, the intelligent control model of hot blast stoves is gradually applied to on-site practice. The focus of model development is to predict and manage the amount of burned fuel, use intelligent control methods, and predict the gas consumption of a single furnace to reasonably optimize load control, thereby reducing the consumption of the hot blast stove.

[0004] The invention patent (CN202110159816.9) discloses a large-scale blast furnace hot blast furnace combustion control heat balance technology. The blast furnace hot blast furnace gas is a mixture of blast furnace gas and converter gas from the pipeline network. By realizing the real-time heat balance calculation based on the PLC level in seconds, the amount of gas required for combustion can be calculated according to the target wind temperature, thereby controlling the combustion of the hot blast furnace and achieving the heat balance of combustion and air supply. This technology can well control the amount of gas required for the combustion of the hot blast furnace, which can not only stably deliver the required high wind temperature, but also reduce the excessive heat storage of the hot blast furnace, reduce heat loss, reduce energy consumption, and achieve energy saving and cost reduction.

[0005] The invention patent (CN201010206032.9) provides an intelligent control method for automatic optimization of combustion of hot blast furnaces. It is based on the calculation of total heat supply. By setting the target values ​​of combustion dome temperature and exhaust gas temperature, the air-fuel ratio fuzzy controller optimizes the optimal air-fuel ratio coefficient in real time during the combustion cycle, and adjusts the combustion air flow and mixed coal gas flow in real time; the combustion air flow is controlled by the exhaust gas temperature regulator, the heat supply regulator and the combustion air regulator; the mixed coal gas flow is controlled by the dome temperature regulator and the mixed coal gas regulator; the air-fuel ratio is controlled by the air-fuel ratio fuzzy controller. This technology can improve the combustion control level of hot blast furnaces, with high combustion efficiency, full energy utilization and strong heat storage capacity.

[0006] The invention patent (CN201210312159.8) provides an intelligent optimization control system for a blast furnace hot blast stove. The system realizes online calculation of the heat storage rate based on heat balance, sets a reasonable heat storage rate setting curve according to the total air supply heat required by the blast furnace, the furnace burning time and the heat storage rate characteristics of the hot blast stove, controls the fuel amount in the furnace burning stage in real time according to the heat storage rate, and limits the calculated fuel amount according to the upper limit of the process allowable for the dome temperature and the exhaust gas temperature. The system fully meets the blast furnace's need for hot air, reduces the heat loss carried away by the exhaust gas, and ensures the safety of the equipment. In addition, the heat storage rate is used as the optimization target value, and the advance and retreat method self-optimization algorithm is used to optimize the air-fuel ratio, so that the fuel utilization rate is maximized, ensuring the energy saving of the device from multiple levels.

[0007] The above three existing technologies all involve the calculation of the total heat supply of the hot blast furnace, but fail to fully consider the energy loss of the hot blast furnace in the heat exchange process and the conversion of the heat storage body energy. They only take the heat demand of hot blast as the target, which is bound to cause a large deviation in the calculation of the total heat of the hot blast furnace gas. At the same time, they fail to consider the heat conversion of the hot blast furnace in the process of burning and changing the furnace. The technology given will cause heat imbalance. It can only digest the energy changes brought by the cold and hot furnaces by balancing the burning and air supply time, which will cause energy loss. Summary of the invention

[0008] According to the above technical problem of how to increase the hot blast temperature while reducing the consumption of the hot blast stove, a method for predicting the gas consumption of a hot blast stove based on the judgment of a cold or hot stove is provided. The present invention fully considers the energy conversion of the hot blast stove in the heat exchange process, provides accurate data support for the prediction of the single gas consumption of the hot blast stove, and realizes the precise control of the hot blast stove.

[0009] The technical means adopted by the present invention are as follows:

[0010] A method for predicting gas consumption of a hot blast stove based on judging whether the hot blast stove is cold or hot, comprising:

[0011] Based on the parameter dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟 , determine the furnace condition of the hot blast furnace after furnace replacement;

[0012] According to the determined furnace condition, calculate the residual heat of the hot blast furnace after heat exchange;

[0013] According to the calculated residual heat of the hot blast stove, the amount of gas used to burn the stove is predicted based on the stove condition.

[0014] Furthermore, the parameter based on the dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟, determine the furnace condition of the hot blast furnace after the furnace is replaced, specifically including:

[0015] During the air supply stage of the hot blast furnace, the cold air is heated by the checker bricks, the dome and the combustion chamber to become the hot air required by the blast furnace; during the air supply stage, the dome temperature T 拱 As the air supply process gradually decreases, when the vault temperature T 拱 Equal to the set supply hot air temperature T 风设 When the residual heat of the checker brick is the same as the residual heat before combustion heating, it is in a saturated state. In the saturated state, due to the process requirements for further air supply, the vault temperature T 拱 Further reduce, below the set supply hot air temperature T 风设 , that is, T 拱 <T 风设 , it is determined that the state of the furnace after the furnace replacement is a cold furnace;

[0016] When the air supply time and air supply volume are lower than the vault temperature T 拱 , that is, T 拱 ≥T 风设 , the residual heat of the checker bricks is in an oversaturated state, then the furnace is judged to be a hot furnace after the furnace change.

[0017] Furthermore, the residual heat after heat exchange of the hot blast stove is calculated according to the determined furnace condition, specifically including:

[0018] According to the heat balance theory, the residual heat after the hot air furnace heat exchange is calculated. The calculation formula is as follows:

[0019] Q 余(n) =Q 收(n) -Q 支(n)

[0020] Among them, Q 余(n) It indicates the remaining heat of the hot blast furnace after the nth air supply and furnace change, in Mj / furnace; Q 收(n) It represents the total heat input of the nth hot blast furnace burning process, in Mj / furnace; Q 支(n) It represents the total heat expenditure of the nth air supply process, in Mj / furnace;

[0021] Calculate the total heat Q of the nth hot blast furnace burning process 收(n) , the calculation formula is as follows:

[0022] Q 收(n) =Q 化(n) +Q 物(n) +Q 余(n-1) -Q 烟(n) -Q 失(n)

[0023] Among them, Q 化(n) It indicates the chemical heat brought into the fuel during the nth combustion process; Q物(n) It represents the physical quantity brought by the fuel and combustion air during the nth firing process; Q 余(n-1) It indicates the remaining heat after the n-1th air supply and furnace change, in Mj / furnace; Q 烟(n) Indicates the heat brought out by the flue gas during the nth burning process; Q 失(n) Indicates other heat loss during the nth firing process;

[0024] Calculate the total heat expenditure Q of the nth air supply process 支(n) , the calculation formula is as follows:

[0025] Q 支(n) =Q 风(n) +Q' 失(n)

[0026] Among them, Q 风(n) Indicates the physical heat brought out by the hot air from the nth air supply; Q' 失(n) Indicates other heat loss during the nth air supply process.

[0027] Furthermore, when the remaining heat Q of the hot blast furnace after the nth air supply and furnace change is 余(n) If the result is positive, the furnace condition after the furnace change is a hot furnace. When the residual heat Q of the hot blast furnace after the nth air supply furnace change is 余(n) If the result is negative, the furnace condition after the furnace replacement is a cold furnace.

[0028] Furthermore, the fuel in the nth burning process brings in chemical heat Q 化(n) Calculated according to fuel combustion theory, the unit is Mj / furnace; the physical quantity Q brought in by the fuel and combustion air during the nth furnace burning process 物(n) Calculated according to the energy equation, the unit is Mj / furnace; the heat brought out by the flue gas during the nth furnace burning process is Q 烟(n) Calculated according to the energy equation and fuel combustion theory, the unit is Mj / furnace; the other heat loss Q 失(n) Including furnace heat dissipation, fuel incomplete combustion loss, fuel leakage, thermal balance test calibration can be carried out, or (5% ~ 20%) × Q can be taken according to the state of the hot air furnace 化(n) , the unit is Mj / furnace; the nth hot air supply brings out the physical heat Q 风(n) Calculated according to the energy equation, the unit is Mj / furnace; the other heat loss Q' in the nth air supply process 失(n) Including furnace body heat dissipation and pipeline heat dissipation, thermal balance test calibration can be carried out, and (3%~10%)×Q can be taken according to the state of the hot air furnace. 风(n) , the unit is Mj / furnace.

[0029] Furthermore, the method of predicting the amount of coal gas for burning the furnace based on the furnace condition according to the measured residual heat of the hot blast furnace specifically includes:

[0030] Predict the heat Q required for the n+1th furnace change 化(n+1) , the calculation formula is as follows:

[0031] Q 化(n+1) =Q 风(n+1) +Q 余(n) +∑Q 损(n+1)

[0032] Among them, Q 风(n+1) Indicates the predicted value of heat brought out by hot air at the n+1th furnace change; ∑Q 损(n+1) It represents the total loss prediction value of the n+1th hot blast stove production process;

[0033] Predict the heat load V required for the n+1th furnace change m(n+1) , the calculation formula is as follows:

[0034] V m(n+1) =KQ 化(n+1) / Q d

[0035] Among them, Q d Indicates the lower calorific value of the gas used, in Kj / Nm 3 ; K represents the comprehensive utilization coefficient.

[0036] Furthermore, the predicted value Q of the heat brought out by the hot air during the n+1th furnace change is 风(n+1) The prediction is made by time series or according to the burning status of the same hot blast furnace, and the unit is Mj / furnace; the total loss prediction value ∑Q of the n+1th hot blast furnace production process 损(n+1) , through the time series method, it can also be taken according to the hot blast furnace state (1% ~ 30%) × Q 风(n+1) , the unit is Mj / furnace; the comprehensive utilization coefficient K is 0.2-0.75 according to different types of coal gas and different exhaust gas temperatures.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] 1. The present invention provides a hot blast stove gas consumption prediction method based on the judgment of hot blast stove cold and hot stove, which is used in the combustion gas prediction system of the hot blast stove intelligent control system. It proposes a method for calculating the waste heat of the hot blast stove during each furnace burning and air supply process, and predicts the next hot blast stove burning gas volume based on the waste heat measurement result, providing technical support for the precise control of the hot blast stove.

[0039] 2. The hot blast furnace gas consumption prediction method based on the judgment of the hot blast furnace cold and hot furnace provided by the present invention predicts the gas heat load required for each combustion according to the cold and hot furnace states, thereby ensuring the hot blast temperature is stable while reducing fuel consumption. The method of the present invention can reduce the fuel consumption of the hot blast furnace by more than 5%.

[0040] Based on the above reasons, the present invention can be widely promoted in the fields of energy saving in the steel industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] like Figure 1 As shown, the present invention provides a method for predicting gas consumption of a hot blast furnace based on the judgment of a hot blast furnace cold furnace and a hot furnace, comprising:

[0046] S1, based on the parameter dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟 , determine the furnace condition of the hot blast furnace after furnace replacement;

[0047] S2. Calculate the residual heat of the hot blast furnace after heat exchange according to the determined furnace condition;

[0048] S3. According to the calculated residual heat of the hot blast furnace, the amount of gas used to burn the furnace is predicted based on the furnace condition.

[0049] In specific implementation, as a preferred embodiment of the present invention, in step S1, based on the parameter dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟 , determine the furnace condition of the hot blast furnace after the furnace is replaced, specifically including:

[0050] S11, hot blast furnace air supply stage, the cold air is heated by the checker bricks, the dome and the combustion chamber to become the hot air required by the blast furnace; in the air supply stage, the dome temperature T 拱 As the air supply process gradually decreases, when the vault temperature T 拱 Equal to the set supply hot air temperature T 风设 When the cold wind just takes out the heat of the checker bricks, the remaining heat of the checker bricks is the same as the remaining heat before combustion heating, and is in a saturated state; in the saturated state, due to the process requirements of further air supply, the vault temperature T 拱 Further reduce, below the set supply hot air temperature T 风设 , that is, T 拱 <T 风设 , it is determined that the state of the furnace after the furnace replacement is a cold furnace;

[0051] S12, on the contrary, since the air supply time and air supply volume are lower than the vault temperature T 拱 , that is, T 拱 ≥T 风设 , the residual heat of the checker bricks is in an oversaturated state, then the furnace is judged to be a hot furnace after the furnace change.

[0052] In specific implementation, as a preferred embodiment of the present invention, in step S2, the residual heat after heat exchange of the hot blast stove is calculated according to the determined furnace condition, which specifically includes:

[0053] S21. According to the heat balance theory, calculate the residual heat after the hot air furnace heat exchange. The calculation formula is as follows:

[0054] Q 余(n) =Q 收(n) -Q 支(n)

[0055] Among them, Q 余(n) It indicates the remaining heat of the hot blast furnace after the nth air supply and furnace change, in Mj / furnace; Q 收(n) It represents the total heat input of the nth hot blast furnace burning process, in Mj / furnace; Q 支(n) represents the total heat expenditure during the nth air supply process, in units of Mj / furnace; in this embodiment, when the hot blast furnace has residual heat Q after the nth air supply and furnace change, 余(n)If the result is positive, the furnace condition after the furnace change is a hot furnace. When the residual heat Q of the hot blast furnace after the nth air supply furnace change is 余(n) If the result is negative, the furnace condition after the furnace replacement is a cold furnace.

[0056] S22. Calculate the total heat Q of the nth hot blast furnace burning process 收(n) , the calculation formula is as follows:

[0057] Q 收(n) =Q 化(n) +Q 物(n) +Q 余(n-1) -Q 烟(n) -Q 失(n)

[0058] Among them, Q 化(n) It indicates the chemical heat brought into the fuel during the nth combustion process; Q 物(n) It represents the physical quantity brought by the fuel and combustion air during the nth firing process; Q 余(n-1) It indicates the remaining heat after the n-1th air supply and furnace change, in Mj / furnace; Q 烟(n) Indicates the heat brought out by the flue gas during the nth burning process; Q 失(n) Indicates other heat loss during the nth firing process;

[0059] S23. Calculate the total heat expenditure Q of the nth air supply process 支(n) , the calculation formula is as follows:

[0060] Q 支(n) =Q 风(n) +Q' 失(n)

[0061] Among them, Q 风(n) Indicates the physical heat brought out by the hot air from the nth air supply; Q' 失(n) Indicates other heat loss during the nth air supply process.

[0062] In specific implementation, as a preferred embodiment of the present invention, in step S2, the fuel in the nth burning process brings in chemical heat Q 化(n) Calculated according to fuel combustion theory, the unit is Mj / furnace; the physical quantity Q brought in by the fuel and combustion air during the nth furnace burning process 物(n) Calculated according to the energy equation, the unit is Mj / furnace; the heat brought out by the flue gas during the nth furnace burning process is Q 烟(n) Calculated according to the energy equation and fuel combustion theory, the unit is Mj / furnace; the other heat loss Q 失(n) Including furnace heat dissipation, fuel incomplete combustion loss, fuel leakage, thermal balance test calibration can be carried out, or (5% ~ 20%) × Q can be taken according to the state of the hot air furnace 化(n) , the unit is Mj / furnace; the nth hot air supply brings out the physical heat Q 风(n)Calculated according to the energy equation, the unit is Mj / furnace; the other heat loss Q' in the nth air supply process 失(n) Including furnace body heat dissipation and pipeline heat dissipation, thermal balance test calibration can be carried out, and (3%~10%)×Q can be taken according to the state of the hot air furnace. 风(n) , the unit is Mj / furnace.

[0063] In specific implementation, as a preferred embodiment of the present invention, in step S3, according to the measured residual heat of the hot blast stove, the amount of gas for burning the stove is predicted based on the stove condition, which specifically includes:

[0064] S31. Predict the heat Q required for the n+1th furnace change 化(n+1) , the calculation formula is as follows:

[0065] Q 化(n+1) =Q 风(n+1) +Q 余(n) +∑Q 损(n+1)

[0066] Among them, Q 风(n+1) Indicates the predicted value of heat brought out by hot air at the n+1th furnace change; ∑Q 损(n+1) It represents the total loss prediction value of the n+1th hot blast stove production process;

[0067] S32, predict the heat load V required for the n+1th furnace change m(n+1) , the calculation formula is as follows:

[0068] V m(n+1) =KQ 化(n+1) / Q d

[0069] Among them, Q d Indicates the lower calorific value of the gas used, in Kj / Nm 3 ; K represents the comprehensive utilization coefficient.

[0070] In specific implementation, as a preferred embodiment of the present invention, in step S3, the predicted value of heat brought out by the hot air of the n+1th furnace exchange is Q 风(n+1) Predicted by time series or according to other hot blast furnace burning status, unit is Mj / furnace; the total loss prediction value ∑Q of the n+1th hot blast furnace production process 损(n+1) , through the time series method, it can also be taken according to the hot blast furnace state (1% ~ 30%) × Q 风(n+1) , the unit is Mj / furnace; the comprehensive utilization coefficient K is 0.2-0.75 according to different types of coal gas and different exhaust gas temperatures.

[0071] The present invention provides a method for predicting gas consumption of a hot blast furnace for judging whether the hot blast furnace is cold or hot. The technical principle is as follows: the working mode of the hot blast furnace is alternating combustion / air supply. The residual heat of the hot blast furnace after each air supply has a great influence on the amount of gas for the next combustion. During the combustion period, the lattice bricks are heated by the chemical heat of gas combustion. After the temperature of the lattice bricks is saturated, the high-pressure air brought in by the blast furnace blower is heated after the furnace is changed to reach the target temperature and enters the blast furnace through the blast furnace surrounding pipe for smelting. For the hot blast furnace after heat exchange, the heat of the lattice bricks is taken away by the cold air. When the air supply time is long and the air supply volume is large, the heat of the lattice bricks will be excessively taken out, resulting in the heat of the lattice bricks being lower than the heat supply in the previous combustion process, so that the lattice bricks are in a heat unsaturated state. The hot blast furnace condition in this state is defined as a "cold furnace". Conversely, when the air supply time and the air supply volume are lower than the heat supply, the residual heat of the lattice bricks is in an oversaturated state. The hot blast furnace condition in this state is defined as a "hot furnace". After the hot blast furnace "cold and hot furnace" is replaced, the required heat is quite different according to the heat saturation of the checker bricks. In order to ensure the hot blast temperature is stable and reduce fuel consumption at the same time, the present invention predicts the gas heat load required for each combustion according to the cold and hot furnace states.

[0072] Example 1

[0073] A factory 2580m 3 The blast furnace has three hot blast furnaces, which are internal combustion hot blast furnaces. The combustion method adopts two burning and one sending. The original furnace uses conventional burning method and conventional fuel quantity control method. The furnace gas is blast furnace gas with a calorific value of 800Kcal / Nm 3 , real-time flow rate is 100000Nm 3 / h, furnace burning time 120min, last air supply time 99min, air supply volume 5000Nm 3 / min, the air supply target is 1220℃, the dome temperature after air supply is 1100℃, it is determined that the current hot blast furnace is a cold furnace after the furnace change, and the fuel amount needs to be increased in the next cycle. According to the method of the present invention, the heat loss Q of the hot blast furnace after air supply and furnace change is predicted. 余(n) =-169901Mj / furnace. This part of heat needs to be compensated in the next cycle. According to the working status of other hot blast stoves and the forward operation of the blast furnace, the air supply volume in the next cycle is still 5000Nm 3 / min, air supply target 1220℃, air supply time 87min, then the predicted heating heat of the next cycle is 854504Mj / furnace, gas load Vm=127766Nm 3 / h, which can meet the 120min furnace burning time, and still use 100000Nm 3 / h of furnace load, the combustion time needs to be extended to 153min to meet the heat demand, resulting in a 12.3% increase in heat dissipation and smoke exhaust losses during operation.

[0074] Example 2

[0075] A factory 2580m 3 The blast furnace has three hot blast furnaces, which are internal combustion hot blast furnaces. The combustion method adopted is two burning and one sending. The original furnace burning state adopts the conventional furnace burning method and conventional fuel quantity control method. The furnace burning gas is blast furnace gas with a calorific value of 800Kcal / Nm 3 , real-time flow rate is 100000Nm 3 / h, furnace burning time 120min, last air supply time 76min, air supply volume 5000Nm 3 / min, the air supply target is 1220℃, the dome temperature after air supply is 1100℃, it is determined that the current hot blast furnace is a cold furnace after the furnace change, and the fuel amount needs to be increased in the next cycle. According to the method of the present invention, the heat loss Q of the hot blast furnace after air supply and furnace change is predicted. 余(n) =11086Mj / furnace. This part of heat will reduce the load in the next cycle. According to the working status of other hot blast stoves and the smooth operation of the blast furnace, the air supply volume in the next cycle will still be 5000Nm 3 / min, air supply target 1220℃, air supply time 87min, then the predicted heating heat of the next cycle is 673517Mj / furnace, gas load Vm=92469Nm 3 / h, which can meet the 120min furnace burning time, and still use 100000Nm 3 / h of furnace load, the furnace can be replaced after 110 minutes of burning time. If the 120-minute burning system is still used, energy loss of 5.2% will be caused.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting gas consumption of hot blast stoves based on the judgment of hot and cold stoves, characterized in that: include: Based on the parameter dome temperature T 拱 , hot air temperature T 风 , exhaust temperature T 烟 , determine the furnace condition of the hot blast furnace after the furnace is replaced, specifically including: During the air supply stage of the hot blast furnace, the cold air is heated by the checker bricks, the dome and the combustion chamber to become the hot air required by the blast furnace; during the air supply stage, the dome temperature T 拱 As the air supply process gradually decreases, when the vault temperature T 拱 Equal to the set supply hot air temperature T 风设 When the residual heat of the checker brick is the same as the residual heat before combustion heating, it is in a saturated state. In the saturated state, due to the process requirements of continuous air supply, the vault temperature T 拱 Further reduce, below the set supply hot air temperature T 风设 , that is, T 拱 <T 风设 , it is determined that the state of the furnace after the furnace replacement is a cold furnace; When the air supply time and air supply volume are lower than the vault temperature T 拱 , that is, T 拱 ≥T 风设 , the residual heat of the checker bricks is in an oversaturated state, then the furnace is judged to be a hot furnace after the furnace change; According to the determined furnace condition, the residual heat after the hot blast furnace heat exchange is calculated, including: According to the heat balance theory, the residual heat after the hot air furnace heat exchange is calculated. The calculation formula is as follows: Q 余(n) =Q 收(n) -Q 支(n) Among them, Q 余(n) It indicates the remaining heat of the hot blast furnace after the nth air supply and furnace change, in Mj / furnace; Q 收(n) It represents the total heat input of the nth hot blast furnace burning process, in Mj / furnace; Q 支(n) It represents the total heat expenditure of the nth air supply process, in Mj / furnace; Calculate the total heat Q of the nth hot blast furnace burning process 收(n) , the calculation formula is as follows: Q 收(n) =Q 化(n) +Q 物(n) +Q 余(n-1) -Q 烟(n) -Q 失(n) Among them, Q 化(n) It indicates the chemical heat brought into the fuel during the nth combustion process; Q 物(n) It represents the physical quantity brought in by the fuel and combustion air during the nth firing process; Q 余(n-1) It indicates the remaining heat after the n-1th air supply and furnace change, in Mj / furnace; Q 烟(n) Indicates the heat brought out by the flue gas during the nth burning process; Q 失(n) Indicates other heat loss during the nth firing process; Calculate the total heat expenditure Q of the nth air supply process 支(n) , the calculation formula is as follows: Q 支(n) =Q 风(n) +Q’ 失(n) Among them, Q 风(n) Indicates the physical heat brought out by the hot air from the nth air supply; Q' 失(n) Indicates other heat loss during the nth air supply process; According to the calculated residual heat of the hot blast furnace, the amount of gas burning the furnace is predicted based on the furnace condition, including: Predict the heat Q required for the n+1th furnace change 化(n+1) , the calculation formula is as follows: Q 化(n+1) =Q 风(n+1) +Q 余(n) +∑Q 损(n+1) Among them, Q 风(n+1) Indicates the predicted value of heat brought out by hot air at the n+1th furnace change; ∑Q 损(n+1) It represents the total loss prediction value of the n+1th hot blast stove production process; Predict the heat load V required for the n+1th furnace change m(n+1) , the calculation formula is as follows: V m(n+1) =KQ 化(n+1) / Q d Among them, Q d Indicates the lower calorific value of the gas used, in Kj / Nm 3 ; K represents the comprehensive utilization coefficient.

2. The method for predicting gas consumption of hot blast stoves based on the judgment of hot blast stove cold and hot stoves according to claim 1 is characterized in that: When the remaining heat Q of the hot blast furnace after the nth air supply and furnace change 余(n) If the result is positive, the furnace condition after the furnace change is a hot furnace. When the residual heat Q of the hot blast furnace after the nth air supply furnace change is 余(n) If the result is negative, the furnace condition after the furnace replacement is a cold furnace.

3. The method for predicting gas consumption of hot blast stoves based on the judgment of hot blast stove cold and hot stoves according to claim 1 is characterized in that: The fuel in the nth burning process brings in chemical heat Q 化(n) Calculated according to fuel combustion theory, the unit is Mj / furnace; The fuel and combustion air in the nth burning process bring in the physical quantity Q 物(n) Calculated according to the energy equation, the unit is Mj / furnace; The flue gas from the nth burning process brings out heat Q 烟(n) Calculated according to the energy equation and fuel combustion theory, the unit is Mj / furnace; the other heat loss Q 失(n) Including furnace heat dissipation, furnace heat storage, fuel incomplete combustion loss, fuel leakage, thermal balance test calibration can be carried out, or (5% ~ 20%) × Q can be taken according to the state of the hot air furnace 化(n) , the unit is Mj / furnace; the nth hot air supply brings out the physical heat Q 风(n) Calculated according to the energy equation, the unit is Mj / furnace; The other heat loss Q' in the nth air supply process 失(n) Including furnace body heat dissipation and pipeline heat dissipation, thermal balance test calibration can be carried out, and (3%~10%)×Q can be taken according to the state of the hot air furnace. 风(n) , the unit is Mj / furnace.

4. The method for predicting gas consumption of hot blast stoves based on judgment of hot and cold stoves according to claim 1, characterized in that: The predicted value Q of the heat brought out by the hot air during the n+1th furnace replacement 风(n+1) The prediction is made by time series or according to the burning status of the same hot blast furnace, and the unit is Mj / furnace; the total loss prediction value ∑Q of the n+1th hot blast furnace production process 损(n+1) , through the time series method, it can also be taken according to the hot blast furnace state (1% ~ 30%) × Q 风(n+1) , the unit is Mj / furnace; the comprehensive utilization coefficient K is 0.2-0.75 according to different types of coal gas and different exhaust gas temperatures.

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