Combustion control method and combustion control device for hot blast stove

Abstract

A combustion control method for a hot-blast stove according to the present invention comprises: a combustion step in which heat introduced by combusting a mixed gas is stored in a heat storage chamber; an air blowing step for generating hot air by supplying cold air into the heat storage chamber, and supplying the generated hot air to the blast furnace; the combustion control method for the hot-blast stove includes the steps of calculating an actual value of heat, calculating heat consumed by generating hot air, calculating an actual value of thermal efficiency of the hot-blast stove, calculating heat to be input when generating hot air next time, calculating the amount of mixed gas to be supplied when generating hot air next time, and calculating the amount of mixed gas to be supplied when generating hot air next time. The hot-blast stove is controlled on the basis of the calculated amount of the mixed gas.

Description

Technical Field

[0001] The present invention relates to a combustion control method and a combustion control device for a hot blast stove that supplies hot air to a blast furnace. Background Art

[0002] A combustion control method for a hot blast stove is described in Patent Document 1. When there is insufficient combustion time due to equipment failure, the amount of input gas is increased to supplement the amount corresponding to the shortage of combustion time, thereby maintaining the temperature of the hot air supplied to the blast furnace.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 10-226808 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] Even if the amount of gas input to the hot blast stove is stably managed, due to error factors such as changes in the calorific value of the gas and a decrease in the heat storage capacity caused by blockage of the heat storage bricks in the hot blast stove, heat excess or heat deficiency in the hot blast stove may occur. In the case of heat excess, gas is excessively input to the hot blast stove, resulting in deteriorated operating costs. On the other hand, in the case of heat deficiency, the blowing temperature decreases, and the furnace condition of the blast furnace deteriorates due to a decrease in the heat of the blast furnace.

[0008] The present invention has been made in view of the above technical problems, and an object thereof is to provide a combustion control method and a combustion control device for a hot blast stove that can suppress heat excess or heat deficiency in the hot blast stove.

[0009] Technical Solution for Solving the Technical Problem

[0010] The combustion control method for the hot blast stove of the present invention includes: a combustion step of accumulating the heat input by burning a mixed gas in a heat storage chamber; a blowing step of generating hot air by supplying cold air to the heat storage chamber and supplying the generated hot air to the blast furnace, and is characterized by including the following steps: calculating the actual value of the heat as the actual heat input amount Q using the following calculation formula (1) in , calculating the heat consumed by generating the hot air as the actual heat output amount Q using the following calculation formula (2) out , calculating the actual value of the thermal efficiency of the hot blast stove as the actual thermal efficiency η using the following calculation formula (3), and calculating the heat to be input when generating hot air next time as the necessary heat input amount Q using the following calculation formula (4) inHS , calculating the amount V of the mixed gas to be supplied when generating hot air next time using the following calculation formula (5) M_B, control the hot blast stove based on the calculated amount V of the mixed gas M_B

[0011] [[Calculation formula 1]]

[0012]

[0013] t A : Combustion elapsed time [min], k M : Calorific value of gas M [J / Nm 3

[0014] V M : Flow rate of gas M [Nm 3 / min], T AIR : Combustion air temperature,

[0015] C AIR : Specific heat of combustion air [J / g / ℃]

[0016] V AIR : Flow rate of combustion air [Nm 3 / min], M AIR : Specific heat of combustion air [J / g / ℃]

[0017] T M : Temperature of gas M [℃], C M : Specific heat of gas M [J / g / ℃]

[0018] V M : Flow rate of gas M [Nm 3 / min], M M : Molecular weight of gas M [g / mol]

[0019] [[Calculation formula 2]]

[0020]

[0021] t B : Blowing elapsed time [min], T b : Blowing temperature [℃],

[0022] C bN2 : Specific heat of N2 equivalent to 1200℃ [J / g / ℃], T C : Cold air temperature [℃],

[0023] C CN2 : Specific heat of N2 equivalent to 200℃ [J / g / ℃], Vb: Blowing flow rate [Nm 3 / min],

[0024] M N2 : Molecular weight of N2 [g / mol], C bO2 ​​: Specific heat of O₂ equivalent to 1200 °C [J / g / °C],

[0025] C CO2 : Specific heat of O₂ equivalent to 200 °C [J / g / °C], V O2 : Total O₂ flow rate [Nm 3 / min],

[0026] V OXY : O₂ flow rate [Nm 3 / min], M O2 : Specific heat of O₂ [J / g / °C],

[0027] C bmoi : Specific heat of steam equivalent to 1200 °C [J / g / °C],

[0028] C Cmoi : Specific heat of steam equivalent to 200 °C [J / g / °C],

[0029] moi: Air supply temperature [g / Nm 3 ,

[0030] [Calculation formula 3]

[0031]

[0032] [Calculation formula 4]

[0033]

[0034] [Calculation formula 5]

[0035]

[0036] α: Air-fuel ratio.

[0037] It may include the following steps: When the air supply parameters of the blast furnace are changed, use the following calculation formula (6) to calculate the predicted value Q of the heat consumed by generating the hot air out预测 , use the following calculation formula (7) to calculate the required heat as the necessary heat input Q for obtaining the predicted value Q of the heat out预测 , and control the hot blast stove based on the calculated necessary heat input Q in预测 . in预测

[0038] [Calculation formula 6]

[0039]

[0040] T b设定 : Air supply temperature set value, V b设定 : Air supply flow rate set value,

[0041] V O2设定 : Total oxygen flow rate set value

[0042] V OXY设定 : Oxygen flow rate set value

[0043] [Calculation formula 7]

[0044]

[0045] It may also include the following steps: calculating the correction amount α of the actual thermal efficiency η using the opening degree after the end of the air supply process of the air supply butterfly valve provided between the regenerator and the air blower for supplying cold air to the regenerator, and calculating the corrected value η of the actual thermal efficiency η using the following calculation formula (8) 修正 , and using the calculated corrected value η 修正 for the next process.

[0046] [Calculation formula 8]

[0047]

[0048] The combustion control device of the hot blast stove of the present invention has: a combustion process for accumulating the heat input by burning a mixed gas in a regenerator; an air supply process for generating hot air by supplying cold air into the regenerator and supplying the generated hot air to a blast furnace, and is characterized in that it includes the following units: calculating the actual value of the heat as the actual heat input amount Q using the following calculation formula (1) in , calculating the heat consumed by generating the hot air as the actual heat output amount Q using the following calculation formula (2) out , calculating the actual value of the thermal efficiency of the hot blast stove as the actual thermal efficiency η using the following calculation formula (3), and calculating the heat to be input when generating hot air next time as the necessary heat input amount Q using the following calculation formula (4) inHS , calculating the amount V of the mixed gas to be supplied when generating hot air next time using the following calculation formula (5) M_B , and controlling the hot blast stove based on the calculated amount V of the mixed gas M_B .

[0049] [Calculation formula 9]

[0050]

[0051] t A : Combustion elapsed time [min], k M : Calorific value of gas M [J / Nm 3 ,

[0052] V M : Gas M flow rate [Nm 3 / min], TAIR : Combustion air temperature,

[0053] C AIR : Specific heat of combustion air [J / g / °C]

[0054] V AIR : Combustion air flow rate [Nm 3 / min], M AIR : Specific heat of combustion air [J / g / °C]

[0055] T M : Temperature of gas M [°C], C M : Specific heat of gas M [J / g / °C]

[0056] V M : Flow rate of gas M [Nm 3 / min], M M : Molecular weight of gas M [g / mol]

[0057] [Calculation formula 10]

[0058]

[0059] t B : Time elapsed for air supply [min], T b : Air supply temperature [°C],

[0060] C bN2 : Specific heat of N2 equivalent to 1200°C [J / g / °C], T C : Cold air temperature [°C],

[0061] C CN2 : Specific heat of N2 equivalent to 200°C [J / g / °C], Vb: Air supply flow rate [Nm 3 / min],

[0062] M N2 : Molecular weight of N2 [g / mol], C bO2 : Specific heat of O2 equivalent to 1200°C [J / g / °C],

[0063] C CO2 : Specific heat of O2 equivalent to 200°C [J / g / °C], V O2 : Total O2 flow rate [Nm 3 / min],

[0064] V OXY : Oxygen flow rate [Nm 3 / min], M O2 : Specific heat of O2 [J / g / °C],

[0065] C bmoi: Specific heat of steam equivalent to 1200 °C [J / g / °C],

[0066] C Cmoi : Specific heat of steam equivalent to 200 °C [J / g / °C],

[0067] moi: Air supply temperature [g / Nm 3

[0068] [Calculation formula 11]

[0069]

[0070] [Calculation formula 12]

[0071]

[0072] [Calculation formula 13]

[0073]

[0074] α: Air-fuel ratio.

[0075] Advantages of the Invention

[0076] According to the combustion control method and combustion control device of the hot blast stove of the present invention, it is possible to suppress heat excess or heat shortage in the hot blast stove. Brief Description of the Drawings

[0077] Figure 1 It is a schematic diagram showing the structure of a hot blast stove according to an embodiment of the present invention.

[0078] Figure 2 It is used to Figure 1 explain the operation of the hot blast stove shown.

[0079] Figure 3 It is a flowchart showing the process of the combustion control process according to an embodiment of the present invention.

[0080] Figure 4 It is a flowchart showing the process of the combustion control process when the air supply parameters are changed.

[0081] Figure 5 It is a diagram showing an example of the daily change of the fuel consumption per unit when the combustion control process according to an embodiment of the present invention is executed and not executed.

[0082] Figure 6 It is shown Figure 3 a flowchart showing the process of a modified example of the combustion control process shown.

[0083] Figure 7 It is a diagram showing an example of the relationship between the opening degree of the air supply butterfly valve and the presence or absence of correction of the actual thermal efficiency η.

[0084] Figure 8 This is a diagram showing an example of the changes in the heat output, heat input, and M gas flow rate when the blast furnace air supply flow rate decreases after the introduction of the present invention.

[0085] Figure 9 This is a diagram showing an example of the relationship between the heat output and heat input when the blast furnace air supply flow rate decreases before and after the introduction of the present invention. Detailed implementation mode

[0086] Hereinafter, with reference to the accompanying drawings, a combustion control method and a combustion control device for a hot blast stove according to an embodiment of the present invention will be described.

[0087] 〔Structure〕

[0088] First, with reference to Figure 1 and Figure 2 the structure of the hot blast stove according to an embodiment of the present invention will be described. Figure 1 This is a schematic diagram showing the structure of the hot blast stove according to an embodiment of the present invention. Figure 2 This is for Figure 1 illustrating the operation of the hot blast stove shown.

[0089] As Figure 1 shown, the hot blast stove 1 according to an embodiment of the present invention is composed of four hot blast stoves 1a to 1d that supply hot air to the blast furnace 2, and includes combustion blowers 10a to 10c, a heat exchanger 11, an M gas preheater 12, a blower 13, combustion chambers 14a to 14d, and regenerators 15a to 15d. Figure 1 The hot blast stove 1 shown performs parallel operation of the four hot blast stoves 1a to 1d, but the present invention is not limited to this embodiment, and both internal combustion and external combustion hot blast stoves can be applied.

[0090] The combustion blowers 10a to 10c supply air to the heat exchanger 11.

[0091] The heat exchanger 11 heats the air by exchanging heat between the air supplied from the combustion blowers 10a to 10c and the gas (exhaust gas) discharged from the regenerators 15a to 15d to generate combustion air, and supplies the generated combustion air to the combustion chambers 14a to 14d.

[0092] The M gas preheater 12 preheats a mixed gas (M gas) such as coke gas and converter gas and supplies it to the combustion chambers 14a to 14d.

[0093] The blower 13 supplies cold air to the regenerators 15a to 15d. The air supply volume to the regenerators 15a to 15d can be adjusted by controlling the opening degrees of the air supply butterfly valves CB1 to CB4 provided between the blower 13 and each regenerator 15a to 15d.

[0094] The combustion chambers 14a to 14d use the combustion air supplied from the heat exchanger 11 to burn the M gas, and heat the heat storage bricks inside the heat storage chambers 15a to 15d with the combustion exhaust gas thereof.

[0095] The heat storage chambers 15a to 15d heat up the cold air supplied from the blower 13 by means of the heated heat storage bricks to generate hot air, and supply the generated hot air to the blast furnace 2.

[0096] When supplying hot air to the blast furnace 2 using the hot blast stove 1 having such a structure, first, as Figure 2 shown in (a), in the combustion chambers 14a to 14d, the M gas is burned using the combustion air supplied from the heat exchanger 11, and the heat storage bricks inside the heat storage chambers 15a to 15d are heated with the combustion exhaust gas thereof (combustion process). That is, in the combustion process, heat Q is input (accumulated) into the hot blast stove 1 by heating the heat storage bricks. IN Then, as Figure 2 shown in (b), in the heat storage chambers 15a to 15d, the cold air supplied from the blower 13 is heated up by means of the heated heat storage bricks to generate hot air, and the generated hot air is supplied to the blast furnace 2 (air supply process). That is, in the air supply process, hot air is generated by means of the heated heat storage bricks, whereby heat Q is output from the hot blast stove 1. out .

[0097] [Combustion control method]

[0098] In the hot blast stove 1 having such a structure, a control device composed of a computer or the like executes the following combustion control process, thereby suppressing the occurrence of heat excess or heat deficiency. Hereinafter, with reference to Figure 3 the operation of the control device when executing the combustion control process will be described.

[0099] Figure 3 is a flowchart showing the flow of the combustion control process according to an embodiment of the present invention. Figure 3 The flowchart shown starts at the moment when the operation of the hot blast stove 1 is instructed, and the combustion control process proceeds to the process of step S1.

[0100] In the process of step S1, the control device starts the combustion process. Thereby, the process of step S1 is completed, and the combustion control process proceeds to the process of step S2.

[0101] In the process of step S2, the control device calculates the actual value of the heat input amount to the hot blast stove as the actual heat input amount Q by accumulating the heat input to the hot blast stove. in Specifically, the control device calculates the actual heat input amount Q using the following calculation formula (1). inThat is, the control device calculates the sum of the heat input of gas M, the latent heat of combustion air, and the latent heat of gas M as the actual heat input Q. in Thus, the process of step S2 is completed, and the combustion control process proceeds to the process of step S3.

[0102] [Calculation formula 14]

[0103]

[0104] t A : Combustion elapsed time [min], k M : Calorific value of gas M [J / Nm 3

[0105] V M : Flow rate of gas M [Nm 3 / min], T AIR : Combustion air temperature,

[0106] C AIR : Specific heat of combustion air [J / g / ℃]

[0107] V AIR : Flow rate of combustion air [Nm 3 / min], M AIR : Specific heat of combustion air [J / g / ℃]

[0108] T M : Temperature of gas M [℃], C M : Specific heat of gas M [J / g / ℃]

[0109] V M : Flow rate of gas M [Nm 3 / min], M M : Molecular weight of gas M [g / mol]

[0110] In the process of step S3, the control device ends the combustion process. Thus, the process of step S3 is completed, and the combustion control process proceeds to the process of step S4.

[0111] In the process of step S4, the control device starts the air supply process. Thus, the process of step S4 is completed, and the combustion control process proceeds to the process of step S5.

[0112] In the process of step S5, the control device calculates the actual value of the heat output of the hot blast stove as the actual heat output Q by accumulating the heat output of the hot blast stove. out Specifically, the control device calculates the actual heat Q using the following calculation formula (2). out That is, the control device calculates the sum of the sensible heat of nitrogen, the sensible heat of oxygen, and the sensible heat of the moisture in the air supply as the actual heat output Q. out ​Thus, the process of step S5 is completed, and the combustion control process proceeds to the process of step S6.

[0113] [Equation 15]

[0114]

[0115] t B : Air supply passing time [min], T b : Air supply temperature [°C],

[0116] C bN2 : Specific heat of N2 equivalent to 1200°C [J / g / °C], T C : Cold air temperature [°C],

[0117] C CN2 : Specific heat of N2 equivalent to 200°C [J / g / °C], Vb: Air supply flow rate [Nm 3 / min],

[0118] M N2 : Molecular weight of N2 [g / mol], C bO2 : Specific heat of O2 equivalent to 1200°C [J / g / °C],

[0119] C CO2 : Specific heat of O2 equivalent to 200°C [J / g / °C], V O2 : Total O2 flow rate [Nm 3 / min],

[0120] V OXY : Oxygen flow rate [Nm 3 / min], M O2 : Specific heat of O2 [J / g / °C],

[0121] C bmoi : Specific heat of water vapor equivalent to 1200°C [J / g / °C],

[0122] C Cmoi : Specific heat of water vapor equivalent to 200°C [J / g / °C],

[0123] moi: Air supply temperature [g / Nm 3

[0124] In the process of step S6, the control device ends the air supply process. Thus, the process of step S6 is completed, and the combustion control process proceeds to the process of step S7.

[0125] In the process of step S7, the control device uses the actual heat input Q in calculated in the process of step S2 and the actual heat output Q outSubstitute into the following calculation formula (3) to calculate the actual value of the thermal efficiency η as the actual thermal efficiency η. Thus, the process of step S7 is completed, and the combustion control process proceeds to the process of step S8.

[0126] [[Calculation formula 16]]

[0127]

[0128] In the process of step S8, the control device substitutes the actual heat output Q calculated in the process of step S5 out and the actual thermal efficiency η calculated in the process of step S7 into the following calculation formula (4) to calculate the heat to be input into the hot blast stove during the next combustion process as the necessary input heat Q inHS . Thus, the process of step S8 is completed, and the combustion control process proceeds to the process of step S9.

[0129] [[Calculation formula 17]]

[0130]

[0131] In the process of step S9, the control device substitutes the necessary input heat Q calculated in the process of step S8 inHS into the following calculation formula (5) to calculate the flow rate V of the M gas required to input the necessary input heat Q inHS . Thus, the process of step S9 is completed, and a series of combustion control processes end. M_B

[0132] [[Calculation formula 18]]

[0133]

[0134] α: air-fuel ratio

[0135] According to the above description, in the combustion control process of an embodiment of the present invention, the control device uses the calculation formula (1) to calculate the actual value of the input heat as the actual heat input Q in , uses the calculation formula (2) to calculate the heat consumed by generating hot air as the actual heat output Q out , uses the calculation formula (3) to calculate the actual value of the thermal efficiency of the hot blast stove as the actual thermal efficiency η, uses the calculation formula (4) to calculate the heat to be input during the next generation of hot air as the necessary input heat Q inHS , uses the calculation formula (5) to calculate the amount V of the mixed gas to be supplied during the next generation of hot air M_B , and controls the hot blast stove based on the calculated amount V of the mixed gas M_B , so that the occurrence of heat excess or heat deficiency in the hot blast stove can be suppressed.

[0136] When there are sudden changes in the blast furnace's air supply parameters, such as a sudden reduction in the blast volume due to the furnace condition or a reduction in the blast volume accompanied by an adjustment in the tapping volume, the input heat becomes excessive and the operating cost deteriorates. Especially in the case of a sudden reduction in the blast volume, since the operator manually controls the input gas volume, it is possible that appropriate control of the input gas volume cannot be achieved due to individual differences among operators. As the blast furnace's air supply parameters, the blast flow rate V b 、total O2 flow rate V O2 、blast temperature T b 、blast humidity moi, and cold air temperature T c can be exemplified. During a failure or tapping volume adjustment, the blast flow rate V b decreases, and the hot blast stove becomes a state with surplus heat, so it is necessary to control the input heat to the hot blast stove to be reduced.

[0137] Therefore, when there is a change in the blast furnace's air supply parameters, it is preferable to control the heat input to the hot blast stove. Specifically, in this case, as shown in the flowchart of Figure 4 , first, the control device determines whether the air supply parameters have changed (step S41). In this embodiment, when the heat output deviation shown in the following calculation formula (9) calculated during the change of the air supply parameters is equal to or greater than the specified value, the control device determines that the air supply parameters have changed.

[0138] [Calculation formula 19]

[0139]

[0140] Q out（基点） : The heat output that is the basis for calculating the heat output deviation

[0141] Q out预测 : The predicted heat output after the change of the air supply parameters

[0142] Then, when it is determined that the air supply parameters have changed, the control device uses the following calculation formula (6) to calculate the predicted heat output Q out预测 after the change of the air supply parameters, and substitutes the calculated predicted heat output Q out预测 into the following formula (7) to calculate the necessary heat input Q in预测 (step S42). Then, the control device calculates the flow rate of gas M input to the hot blast stove based on the calculated necessary heat input Q in预测 (step S43).

[0143] [Calculation formula 20]

[0144]

[0145] T b设定 : The blast temperature set value, Vb设定 : Blast air flow rate set value,

[0146] V O2设定 : Total oxygen flow rate set value

[0147] V OXY设定 : Oxygen flow rate set value

[0148] [Calculation formula 21]

[0149]

[0150] [Correction of thermal efficiency]

[0151] Figure 5 is a diagram showing an example of the daily change in fuel consumption per unit in the case of performing and not performing the combustion control process of an embodiment of the present invention. As Figure 5 shown, it was confirmed that the fuel consumption per unit decreased by performing the combustion control process of an embodiment of the present invention. However, even when the combustion control process of an embodiment of the present invention was performed, there were days when the fuel consumption per unit decreased significantly and days when it decreased slightly. Therefore, the inventors of the present invention investigated in detail the operation content on the days when the fuel consumption per unit decreased slightly. As a result, it was found that there was a tendency for the fuel consumption per unit to decrease slightly on the days when the blast air flow rate was decreased to adjust the tapping volume of the blast furnace and on the days when the decreased blast air flow rate was restored. It is considered that this is because the furnace heat state of the hot blast stove is different from normal during unstable operations.

[0152] Therefore, as a reference for determining the furnace heat state, it is preferable to correct the value of the thermal efficiency η using the opening degrees of the blast air butterfly valves CB1 to CB4 at the end of the blast air supply. Specifically, during the parallel operation of the four hot blast stoves 1a to 1d, the heat of the leading furnace decreases over time. Therefore, the blast air butterfly valve corresponding to the leading furnace is gradually closed, and the opening degree of the blast air butterfly valve of the trailing furnace with sufficient furnace heat is opened, thereby controlling the blast air temperature to be constant. Therefore, the furnace heat state of the hot blast stove after the end of the blast air supply process can be estimated based on the opening degree of the blast air butterfly valve. For example, when the opening degree of the blast air butterfly valve at the end of the blast air supply process is large, it is considered that heat remains in the hot blast stove after the end of the blast air supply process, and more heat than necessary was input during the previous combustion process. When the opening degree of the blast air butterfly valve is large, the hot blast stove is in a state of heat surplus. Therefore, when the heat input during the next combustion process is excessive, the thermal efficiency deteriorates. On the other hand, when the opening degree of the blast air butterfly valve is small, the heat of the hot blast stove is insufficient, so the set blast air temperature cannot be maintained, which may have an adverse effect on the blast furnace operation.

[0153] Then, as Figure 6As shown in the flowchart, after the control device calculates the actual thermal efficiency η in the process of step S27, it determines whether it is necessary to correct the actual thermal efficiency η by adjusting the opening degree of the air supply butterfly valve (step S28). In the present embodiment, as Figure 7 shown, the lower lower limit opening B2, the lower limit opening B1, the upper limit opening A1, and the upper upper limit opening A2 are set for the opening degree of the air supply butterfly valve at the end of the air supply process. The control device determines whether it is necessary to correct the actual thermal efficiency η based on which range the opening degree of the air supply butterfly valve at the end of the air supply process is in Figure 6 shown. Then, when it is determined that it is necessary to correct the actual thermal efficiency η (step S28: Yes), the control device corrects the actual thermal efficiency η according to the opening degree of the air supply butterfly valve.

[0154] Specifically, when the opening degree of the air supply butterfly valve is small, the control device adds a negative correction value α to the thermal efficiency η using the following calculation formula (8), and performs control to increase the amount of M gas input next time to supplement the heat shortage. On the other hand, when the opening degree of the air supply butterfly valve is large, in order to suppress the deterioration of the thermal efficiency caused by heat excess and the remaining input of M gas, the control device adds a positive correction value α to the thermal efficiency η using the following calculation formula (8), and performs control to reduce the amount of M gas input next time to suppress heat excess. On the other hand, when it is determined that it is not necessary to correct the actual thermal efficiency η (step S28: No), the control device proceeds to the process of step S30 for the combustion control process. Figure 6 The contents of the processes of steps S21 to S27 and steps S30 to S31 shown are the same as the contents of the processes of Figure 3 steps S1 to S9 shown, so the description thereof is omitted.

[0155] [Calculation formula 22]

[0156]

[0157] 〔Example〕

[0158] In this example, the present invention is applied to the operation of supplying hot air from four hot blast stoves with a rated air volume of 7000 Nm 3 / min and a rated heat input of 9000 - 10000 MJ / min to a blast furnace with a volume of 4500 m 3 . Figure 8 (a) to (d) show an example of the changes in the heat output, heat input, and M gas flow rate during the reduction of the blast furnace air supply flow rate after the introduction of the present invention. In Figure 8 the examples shown in (a) to (d), the thermal efficiency η: 1.5% is corrected with the air supply butterfly valve opening degree of 65%, and the thermal efficiency η: -7.0% is corrected with the air supply butterfly valve opening degree of 50%. As Figure 8As shown in (a) to (d), as the heat output decreases due to the reduction of the blast furnace blowing flow rate, the heat input also decreases. Thus, according to the present invention, it is confirmed that M gas and operating costs can be reduced according to the change in heat output. In addition, Figure 9 (a) and Figure 9 (b) show an example of the relationship between the heat output and heat input when the blast furnace blowing flow rate is reduced before and after the introduction of the present invention. As shown in Figure 9 (a), before the introduction of the present invention, when the heat output decreases due to individual differences of operators, there are cases where the heat input cannot follow and decrease (region R1). In contrast, as shown in Figure 9 (b), it is confirmed that after the introduction of the present invention, the heat input can follow the decrease in heat output.

[0159] As described above, embodiments applying the invention completed by the inventors have been described, but the present invention is not limited to the description and drawings that are part of the disclosure of the present invention constituting this embodiment. That is, other embodiments, examples, and application techniques completed by those skilled in the art based on this embodiment are all included in the scope of the present invention.

[0160] Industrial Applicability

[0161] According to the present invention, it is possible to provide a combustion control method and a combustion control device for a hot blast stove that can suppress the occurrence of heat excess and heat deficiency in the hot blast stove.

[0162] Explanation of Reference Numerals

[0163] 1, 1a, 1b, 1c, 1d: Hot blast stoves;

[0164] 2: Blast furnace;

[0165] 11: Heat exchanger;

[0166] 12: M gas preheater;

[0167] 13: Blower;

[0168] 14a, 14b, 14c, 14d: Combustion chambers;

[0169] 15a, 15b, 15c, 15d: Regenerators;

[0170] CB1, CB2, CB3, CB4: Blowing butterfly valves.

Claims

1. A combustion control method for a hot blast stove, comprising: a combustion process of accumulating heat input by burning a mixed gas in a regenerator; a blast supply process of generating hot blast by supplying cold air to the regenerator and supplying the generated hot blast to a blast furnace, characterized in that, It includes the following steps: Calculate the actual value of the heat as the actual heat input Q using the following calculation formula (1). in Calculate the heat consumed by generating the hot air as the actual heat output Q using the following calculation formula (2). out Calculate the actual value of the thermal efficiency of the hot blast stove as the actual thermal efficiency η using the following calculation formula (3), and calculate the heat to be input when generating hot air next time as the required heat input Q using the following calculation formula (4). inHS Calculate the amount V of the mixed gas to be supplied when generating hot air next time using the following calculation formula (5). M_B Based on the calculated amount V of the mixed gas M_B control the hot blast stove. [Calculation formula 1] ， t A : Combustion elapsed time [min], k M : Calorific value of gas M [J / Nm 3 ​ V M : Flow rate of gas M [Nm 3 / min], T AIR : Combustion air temperature, C AIR : Specific heat of combustion air [J / g / ℃] V AIR : Combustion air flow rate [Nm 3 / min], M AIR : Specific heat of combustion air [J / g / ℃] T M : Temperature of gas M [°C], C M : Specific heat of gas M [J / g / °C] V M : Flow rate of gas M [Nm 3 / min], M M : Molecular weight of gas M [g / mol] [Calculation formula 2] ， t B : Air supply passing time [min], T b : Air supply temperature [°C], C bN2 : N2 specific heat equivalent to 1200 °C [J / g / °C], T C : Cold air temperature [°C], C CN2 : Specific heat of N2 equivalent to 200 °C [J / g / °C], Vb: Air supply flow rate [Nm 3 / min], M N2 : Molecular weight of N2 [g / mol], C bO2 : Specific heat of O2 equivalent to 1200 °C [J / g / °C], C CO2 : Specific heat of O2 equivalent to 200 °C [J / g / °C], V O2 : Total O2 flow rate [Nm 3 / min], V OXY : Oxygen flow rate [Nm 3 / min], M O2 : Specific heat of O2 [J / g / °C], C bmoi : Specific heat of steam equivalent to 1200 °C [J / g / °C], C Cmoi : Specific heat of steam equivalent to 200 °C [J / g / °C], moi: Supply air temperature [g / Nm 3 ​ [Calculation formula 3] ， [Calculation formula 4] ， [Calculation formula 5] ， α: air-fuel ratio.

2. The combustion control method of the hot blast stove according to claim 1, wherein, It includes the following steps: In the case where the blast parameters of the blast furnace are changed, the predicted value Q of the heat consumed by generating the hot air is calculated using the following calculation formula (6) out预测 , the required heat is calculated as the necessary heat input amount Q using the following calculation formula (7) to obtain the predicted value Q of the heat out预测 in预测 , based on the calculated necessary heat input amount Q in预测 to control the hot blast stove​ [Calculation formula 6] ， T b设定 : Set value of supply air temperature, V b设定 : Set value of supply air flow rate V O2设定 : Total oxygen flow setpoint V OXY设定 : Oxygen flow setpoint [Calculation formula 7] 。 3. The combustion control method of the hot blast stove according to claim 1 or 2, wherein, It includes the following steps: Calculate the correction amount α of the actual thermal efficiency η using the opening degree after the completion of the air supply process of the air supply butterfly valve provided between the regenerator and the air blower that supplies cold air to the regenerator, and calculate the corrected value η of the actual thermal efficiency η using the following calculation formula (8). 修正 and use the calculated corrected value η 修正 for the next process. [Calculation formula 8] 。 4. A combustion control device for a hot blast stove, comprising: a combustion process for accumulating heat input by burning a mixed gas in a heat storage chamber; a blast process for generating hot air by supplying cold air to the heat storage chamber and supplying the generated hot air to a blast furnace, characterized in that, It has the following units: Calculate the actual value of the heat as the actual heat input Q using the following calculation formula (1) in , calculate the heat consumed by generating the hot air as the actual heat output Q using the following calculation formula (2) out , calculate the actual value of the thermal efficiency of the hot blast stove as the actual thermal efficiency η using the following calculation formula (3), and calculate the heat to be input when generating hot air next time as the necessary heat input Q using the following calculation formula (4) inHS , calculate the amount V of the mixed gas to be supplied when generating hot air next time using the following calculation formula (5) M_B , based on the calculated amount V of the mixed gas M_B to control the hot blast stove [Calculation formula 9] ， t A : Combustion elapsed time [min], k M : Calorific value of gas M [J / Nm 3 ​ V M : Flow rate of gas M [Nm 3 / min], T AIR : Combustion air temperature, C AIR : Specific heat of combustion air [J / g / ℃] V AIR : Combustion air flow rate [Nm 3 / min], M AIR : Specific heat of combustion air [J / g / ℃] T M : Temperature of gas M [°C], C M : Specific heat of gas M [J / g / °C] V M : Flow rate of gas M [Nm 3 / min], M M : Molecular weight of gas M [g / mol] [Calculation formula 10] ， t B : Air supply passing time [min], T b : Air supply temperature [°C], C bN2 : Specific heat of N2 equivalent to 1200 °C [J / g / °C], T C : Cold air temperature [°C], C CN2 : Specific heat of N2 equivalent to 200 °C [J / g / °C], Vb: Air supply flow rate [Nm 3 / min], M N2 : Molecular weight of N2 [g / mol], C bO2 : Specific heat of O2 corresponding to 1200 °C [J / g / °C], C CO2 : Specific heat of O2 equivalent to 200 °C [J / g / °C], V O2 : Total O2 flow rate [Nm 3 / min], V OXY : Oxygen flow rate [Nm 3 / min], M O2 : Specific heat of O2 [J / g / °C], C bmoi : Specific heat of steam equivalent to 1200 °C [J / g / °C], C Cmoi : Specific heat of steam equivalent to 200 °C [J / g / °C], moi: Supply air temperature [g / Nm 3 ​ [Calculation formula 11] ， [Calculation formula 12] ， [Calculation formula 13] ， α: air-fuel ratio.

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